memmap2-0.9.3/.cargo_vcs_info.json 0000644 00000000136 00000000001 0012403 0 ustar {
"git": {
"sha1": "5a49e8ab0bda97770a6ed972633dfb862e17cd38"
},
"path_in_vcs": ""
} memmap2-0.9.3/.github/workflows/main.yml 0000644 0000000 0000000 00000005002 10461020230 0016234 0 ustar 0000000 0000000 name: Rust
on: [push, pull_request]
env:
CARGO_TERM_COLOR: always
jobs:
check:
runs-on: ubuntu-latest
steps:
- name: Checkout
uses: actions/checkout@v3
- name: Install toolchain
uses: dtolnay/rust-toolchain@stable
with:
targets: x86_64-pc-windows-gnu
components: clippy, rustfmt
- name: Run checks
env:
CLIPPY_OPTS: --all-targets
run: |
cargo fmt --check
cargo clippy $CLIPPY_OPTS
cargo clippy --target x86_64-pc-windows-gnu $CLIPPY_OPTS
test-win:
runs-on: windows-latest
strategy:
matrix:
target:
- i686-pc-windows-gnu
- i686-pc-windows-msvc
- x86_64-pc-windows-gnu
- x86_64-pc-windows-msvc
steps:
- name: Checkout
uses: actions/checkout@v3
- name: Install toolchain
uses: dtolnay/rust-toolchain@master
with:
toolchain: stable-${{ matrix.target }}
- name: Run tests
run: cargo test --all-features
test-macos:
runs-on: macos-latest
steps:
- name: Checkout
uses: actions/checkout@v3
- name: Install toolchain
uses: dtolnay/rust-toolchain@stable
- name: Run tests
run: cargo test --all-features
test-linux:
runs-on: ubuntu-latest
strategy:
matrix:
target:
- i686-unknown-linux-gnu
- i686-unknown-linux-musl
- x86_64-unknown-linux-gnu
- x86_64-unknown-linux-musl
steps:
- name: Checkout
uses: actions/checkout@v3
- name: Install toolchain
uses: dtolnay/rust-toolchain@stable
with:
target: ${{ matrix.target }}
- name: Install multilib
if: ${{ contains(matrix.target, 'i686-unknown-linux-') }}
run: |
sudo apt update -yqq
sudo apt install gcc-multilib
- name: Run tests
run: cargo test --all-features --target ${{ matrix.target }}
check-stub:
runs-on: ubuntu-latest
steps:
- name: Checkout
uses: actions/checkout@v3
- name: Install toolchain
uses: dtolnay/rust-toolchain@stable
with:
targets: wasm32-unknown-unknown
- name: Run check
run: cargo check --all-features --target wasm32-unknown-unknown
test-msrv:
runs-on: ubuntu-latest
steps:
- name: Checkout
uses: actions/checkout@v3
- name: Install toolchain
uses: dtolnay/rust-toolchain@1.36.0
# do not test, because dev-dependencies do not follow MSRV
- name: Build
run: cargo build --all-features
memmap2-0.9.3/.gitignore 0000644 0000000 0000000 00000000022 10461020230 0013155 0 ustar 0000000 0000000 target
Cargo.lock
memmap2-0.9.3/CHANGELOG.md 0000644 0000000 0000000 00000020733 10461020230 0013011 0 ustar 0000000 0000000 # Change Log
All notable changes to this project will be documented in this file.
The format is based on [Keep a Changelog](http://keepachangelog.com/)
and this project adheres to [Semantic Versioning](http://semver.org/).
## [Unreleased]
## [0.9.3] - 2023-12-19
### Fixed
- Build on Android.
## [0.9.2] - 2023-12-17
### Fixed
- Build on FreeBSD.
## [0.9.1] - 2023-12-16
### Changed
- Added `MmapOptions::huge` method to support mapping hugetlb. Linux only.
[@ollie-etl](https://github.com/ollie-etl)
[@oliverbunting](https://github.com/oliverbunting)
## [0.9.0] - 2023-10-03
### Changed
- The `Advice` struct was split into two enums: `Advice` and `UncheckedAdvice`.
`Advice` can be passed to safe `advise` and `advise_range` methods.
And `UncheckedAdvice` can be passed to unsafe `unchecked_advise`
and `unchecked_advise_range` methods.
[@adamreichold](https://github.com/adamreichold)
## [0.8.0] - 2023-09-25
### Changed
- The `Advice` type is a struct and not an enum now.
[@adamreichold](https://github.com/adamreichold)
### Fixed
- Some of the `Advise` variants were unsound and now require `unsafe` to be constructed.
[@adamreichold](https://github.com/adamreichold)
## [0.7.1] - 2023-06-24
### Fixed
- Mapping beyond 4GB offset on 32 bit glibc. Linux-only.
[@lvella](https://github.com/lvella)
## [0.7.0] - 2023-06-08
### Added
- `Mmap::remap`, `MmapMut::remap` and `MmapRaw::remap`. Linux-only.
[@Phantomical](https://github.com/Phantomical)
- `Advice::PopulateRead` and `Advice::PopulateWrite`. Linux-only.
[@Jesse-Bakker](https://github.com/Jesse-Bakker)
### Changed
- libc crate >= 0.2.143 is required now.
## [0.6.2] - 2023-05-24
### Fixed
- Alignment for empty files on Windows.
[@timvisee](https://github.com/timvisee)
## [0.6.1] - 2023-05-10
### Added
- Add `MmapOptions::map_raw_read_only` to avoid intermediate invalid `Mmap` instances.
[@adamreichold](https://github.com/adamreichold)
## [0.6.0] - 2023-05-09
### Changed
- `lock()` and `unlock` methods require `&self` and not `&mut self` now.
[@timvisee](https://github.com/timvisee)
## [0.5.10] - 2023-02-22
### Added
- `MmapOptions::map_anon` accounts for `populate` on Linux now.
[@jsgf](https://github.com/jsgf)
## [0.5.9] - 2023-02-17
### Added
- `From for MmapRaw` and `From for MmapRaw`.
[@swlynch99](https://github.com/swlynch99)
- `Mmap::advise_range`, `MmapMut::advise_range`, `MmapRaw::advise_range`.
[@ho-229](https://github.com/ho-229)
## [0.5.8] - 2022-11-09
### Added
- `MmapRaw::advise`, `MmapRaw::lock` and `MmapRaw::unlock`.
[@diwic](https://github.com/diwic)
- Improve `MmapMut::make_exec` documentation.
## [0.5.7] - 2022-08-15
### Changed
- Simplify file size retrieving code.
[@saethlin](https://github.com/saethlin)
## [0.5.6] - 2022-08-11
### Added
- Memory locking and unlocking. See `Mmap::lock`, `Mmap::unlock`,
`MmapMut::lock` and `MmapMut::unlock`.
[@vmx](https://github.com/vmx)
## [0.5.5] - 2022-07-09
### Fixed
- Limit mapping length to `isize::MAX` to prevent undefined behavior
on calling `std::slice::from_raw_parts`. Technically affects only 32-bit systems.
[@adamreichold](https://github.com/adamreichold)
## [0.5.4] - 2022-06-04
### Added
- Add madvice operations specific to Darwin. [@turbocool3r](https://github.com/turbocool3r)
- Implement common traits for the `Advice` enum. [@nyurik](https://github.com/nyurik)
### Changed
- Make stub implementation Infallible. [@coolreader18](https://github.com/coolreader18)
- Use `tempfile` crate instead of `tempdir` in tests.
[@alexanderkjall](https://github.com/alexanderkjall)
## [0.5.3] - 2022-02-10
### Added
- `Mmap::advise` and `MmapMut::advise`. [@nyurik](https://github.com/nyurik)
## [0.5.2] - 2022-01-10
### Added
- `flush`, `flush_async`, `flush_range` and `flush_async_range` to `MmapRaw` matching
the corresponding methods on `MmapMut`.
[@cberner](https://github.com/cberner)
## [0.5.1] - 2022-01-09
### Fixed
- Explicitly call `fstat64` on Linux, emscripten and l4re targets.
[@adamreichold](https://github.com/adamreichold)
## [0.5.0] - 2021-09-19
### Added
- `MmapOptions` accepts any type that supports `RawHandle`/`RawFd` returning now.
This allows using `memmap2` not only with Rust std types, but also with
[async-std](https://github.com/async-rs/async-std) one.
[@adamreichold](https://github.com/adamreichold)
- (unix) Memoize page size to avoid repeatedly calling into sysconf machinery.
[@adamreichold](https://github.com/adamreichold)
### Changed
- (win) Use `std::os::windows::io::AsRawHandle` directly, without relying on `std::fs::File`.
[@adamreichold](https://github.com/adamreichold)
- Do not panic when failing to release resources in Drop impls.
[@adamreichold](https://github.com/adamreichold)
## [0.4.0] - 2021-09-16
### Added
- Optional [`StableDeref`](https://github.com/storyyeller/stable_deref_trait) support.
[@SimonSapin](https://github.com/SimonSapin)
### Changed
- Mapping of zero-sized files is no longer an error.
[@SimonSapin](https://github.com/SimonSapin)
- MSRV changed from 1.31 to 1.36
## [0.3.1] - 2021-08-15
### Fixed
- Integer overflow during file length calculation on 32bit targets.
- Stub implementation. [@Mrmaxmeier](https://github.com/Mrmaxmeier)
## [0.3.0] - 2021-06-10
### Changed
- `MmapOptions` allows mapping using Unix descriptors and not only `std::fs::File` now.
[@mripard](https://github.com/mripard)
## [0.2.3] - 2021-05-24
### Added
- Allow compilation on unsupported platforms.
The code will panic on access just like in `std`.
[@jcaesar](https://github.com/jcaesar)
## [0.2.2] - 2021-04-03
### Added
- `MmapOptions::populate`. [@adamreichold](https://github.com/adamreichold)
### Fixed
- Fix alignment computation for `flush_async` to match `flush`.
[@adamreichold](https://github.com/adamreichold)
## [0.2.1] - 2021-02-08
### Added
- `MmapOptions::map_raw` and `MmapRaw`. [@diwic](https://github.com/diwic)
## [0.2.0] - 2020-12-19
### Changed
- MSRV is 1.31 now (edition 2018).
- Make anonymous memory maps private by default on unix. [@CensoredUsername](https://github.com/CensoredUsername)
- Add `map_copy_read_only`. [@zseri](https://github.com/zseri)
## 0.1.0 - 2020-01-18
### Added
- Fork [memmap-rs](https://github.com/danburkert/memmap-rs).
### Changed
- Use `LICENSE-APACHE` instead of `README.md` for some tests since it's immutable.
### Removed
- `winapi` dependency. [memmap-rs/pull/89](https://github.com/danburkert/memmap-rs/pull/89)
[Unreleased]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.9.3...HEAD
[0.9.3]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.9.2...v0.9.3
[0.9.2]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.9.1...v0.9.2
[0.9.1]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.9.0...v0.9.1
[0.9.0]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.8.0...v0.9.0
[0.8.0]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.7.1...v0.8.0
[0.7.1]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.7.0...v0.7.1
[0.7.0]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.6.2...v0.7.0
[0.6.2]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.6.1...v0.6.2
[0.6.1]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.6.0...v0.6.1
[0.6.0]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.5.10...v0.6.0
[0.5.10]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.5.9...v0.5.10
[0.5.9]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.5.8...v0.5.9
[0.5.8]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.5.7...v0.5.8
[0.5.7]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.5.6...v0.5.7
[0.5.6]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.5.5...v0.5.6
[0.5.5]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.5.4...v0.5.5
[0.5.4]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.5.3...v0.5.4
[0.5.3]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.5.2...v0.5.3
[0.5.2]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.5.1...v0.5.2
[0.5.1]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.5.0...v0.5.1
[0.5.0]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.4.0...v0.5.0
[0.4.0]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.3.1...v0.4.0
[0.3.1]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.3.0...v0.3.1
[0.3.0]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.2.3...v0.3.0
[0.2.3]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.2.2...v0.2.3
[0.2.2]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.2.1...v0.2.2
[0.2.1]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.2.0...v0.2.1
[0.2.0]: https://github.com/RazrFalcon/memmap2-rs/compare/v0.1.0...v0.2.0
memmap2-0.9.3/Cargo.lock 0000644 00000015666 00000000001 0010374 0 ustar # This file is automatically @generated by Cargo.
# It is not intended for manual editing.
version = 3
[[package]]
name = "bitflags"
version = "1.3.2"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
[[package]]
name = "bitflags"
version = "2.4.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "327762f6e5a765692301e5bb513e0d9fef63be86bbc14528052b1cd3e6f03e07"
[[package]]
name = "cfg-if"
version = "1.0.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
[[package]]
name = "errno"
version = "0.3.8"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "a258e46cdc063eb8519c00b9fc845fc47bcfca4130e2f08e88665ceda8474245"
dependencies = [
"libc",
"windows-sys 0.52.0",
]
[[package]]
name = "fastrand"
version = "2.0.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "25cbce373ec4653f1a01a31e8a5e5ec0c622dc27ff9c4e6606eefef5cbbed4a5"
[[package]]
name = "libc"
version = "0.2.151"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "302d7ab3130588088d277783b1e2d2e10c9e9e4a16dd9050e6ec93fb3e7048f4"
[[package]]
name = "linux-raw-sys"
version = "0.4.12"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "c4cd1a83af159aa67994778be9070f0ae1bd732942279cabb14f86f986a21456"
[[package]]
name = "memmap2"
version = "0.9.3"
dependencies = [
"libc",
"owning_ref",
"stable_deref_trait",
"tempfile",
]
[[package]]
name = "owning_ref"
version = "0.4.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "6ff55baddef9e4ad00f88b6c743a2a8062d4c6ade126c2a528644b8e444d52ce"
dependencies = [
"stable_deref_trait",
]
[[package]]
name = "redox_syscall"
version = "0.4.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "4722d768eff46b75989dd134e5c353f0d6296e5aaa3132e776cbdb56be7731aa"
dependencies = [
"bitflags 1.3.2",
]
[[package]]
name = "rustix"
version = "0.38.28"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "72e572a5e8ca657d7366229cdde4bd14c4eb5499a9573d4d366fe1b599daa316"
dependencies = [
"bitflags 2.4.1",
"errno",
"libc",
"linux-raw-sys",
"windows-sys 0.52.0",
]
[[package]]
name = "stable_deref_trait"
version = "1.2.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "a8f112729512f8e442d81f95a8a7ddf2b7c6b8a1a6f509a95864142b30cab2d3"
[[package]]
name = "tempfile"
version = "3.8.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "7ef1adac450ad7f4b3c28589471ade84f25f731a7a0fe30d71dfa9f60fd808e5"
dependencies = [
"cfg-if",
"fastrand",
"redox_syscall",
"rustix",
"windows-sys 0.48.0",
]
[[package]]
name = "windows-sys"
version = "0.48.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "677d2418bec65e3338edb076e806bc1ec15693c5d0104683f2efe857f61056a9"
dependencies = [
"windows-targets 0.48.5",
]
[[package]]
name = "windows-sys"
version = "0.52.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
dependencies = [
"windows-targets 0.52.0",
]
[[package]]
name = "windows-targets"
version = "0.48.5"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "9a2fa6e2155d7247be68c096456083145c183cbbbc2764150dda45a87197940c"
dependencies = [
"windows_aarch64_gnullvm 0.48.5",
"windows_aarch64_msvc 0.48.5",
"windows_i686_gnu 0.48.5",
"windows_i686_msvc 0.48.5",
"windows_x86_64_gnu 0.48.5",
"windows_x86_64_gnullvm 0.48.5",
"windows_x86_64_msvc 0.48.5",
]
[[package]]
name = "windows-targets"
version = "0.52.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "8a18201040b24831fbb9e4eb208f8892e1f50a37feb53cc7ff887feb8f50e7cd"
dependencies = [
"windows_aarch64_gnullvm 0.52.0",
"windows_aarch64_msvc 0.52.0",
"windows_i686_gnu 0.52.0",
"windows_i686_msvc 0.52.0",
"windows_x86_64_gnu 0.52.0",
"windows_x86_64_gnullvm 0.52.0",
"windows_x86_64_msvc 0.52.0",
]
[[package]]
name = "windows_aarch64_gnullvm"
version = "0.48.5"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "2b38e32f0abccf9987a4e3079dfb67dcd799fb61361e53e2882c3cbaf0d905d8"
[[package]]
name = "windows_aarch64_gnullvm"
version = "0.52.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "cb7764e35d4db8a7921e09562a0304bf2f93e0a51bfccee0bd0bb0b666b015ea"
[[package]]
name = "windows_aarch64_msvc"
version = "0.48.5"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "dc35310971f3b2dbbf3f0690a219f40e2d9afcf64f9ab7cc1be722937c26b4bc"
[[package]]
name = "windows_aarch64_msvc"
version = "0.52.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "bbaa0368d4f1d2aaefc55b6fcfee13f41544ddf36801e793edbbfd7d7df075ef"
[[package]]
name = "windows_i686_gnu"
version = "0.48.5"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "a75915e7def60c94dcef72200b9a8e58e5091744960da64ec734a6c6e9b3743e"
[[package]]
name = "windows_i686_gnu"
version = "0.52.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "a28637cb1fa3560a16915793afb20081aba2c92ee8af57b4d5f28e4b3e7df313"
[[package]]
name = "windows_i686_msvc"
version = "0.48.5"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "8f55c233f70c4b27f66c523580f78f1004e8b5a8b659e05a4eb49d4166cca406"
[[package]]
name = "windows_i686_msvc"
version = "0.52.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "ffe5e8e31046ce6230cc7215707b816e339ff4d4d67c65dffa206fd0f7aa7b9a"
[[package]]
name = "windows_x86_64_gnu"
version = "0.48.5"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "53d40abd2583d23e4718fddf1ebec84dbff8381c07cae67ff7768bbf19c6718e"
[[package]]
name = "windows_x86_64_gnu"
version = "0.52.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "3d6fa32db2bc4a2f5abeacf2b69f7992cd09dca97498da74a151a3132c26befd"
[[package]]
name = "windows_x86_64_gnullvm"
version = "0.48.5"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "0b7b52767868a23d5bab768e390dc5f5c55825b6d30b86c844ff2dc7414044cc"
[[package]]
name = "windows_x86_64_gnullvm"
version = "0.52.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "1a657e1e9d3f514745a572a6846d3c7aa7dbe1658c056ed9c3344c4109a6949e"
[[package]]
name = "windows_x86_64_msvc"
version = "0.48.5"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "ed94fce61571a4006852b7389a063ab983c02eb1bb37b47f8272ce92d06d9538"
[[package]]
name = "windows_x86_64_msvc"
version = "0.52.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "dff9641d1cd4be8d1a070daf9e3773c5f67e78b4d9d42263020c057706765c04"
memmap2-0.9.3/Cargo.toml 0000644 00000002153 00000000001 0010402 0 ustar # THIS FILE IS AUTOMATICALLY GENERATED BY CARGO
#
# When uploading crates to the registry Cargo will automatically
# "normalize" Cargo.toml files for maximal compatibility
# with all versions of Cargo and also rewrite `path` dependencies
# to registry (e.g., crates.io) dependencies.
#
# If you are reading this file be aware that the original Cargo.toml
# will likely look very different (and much more reasonable).
# See Cargo.toml.orig for the original contents.
[package]
edition = "2018"
name = "memmap2"
version = "0.9.3"
authors = [
"Dan Burkert ",
"Yevhenii Reizner ",
]
description = "Cross-platform Rust API for memory-mapped file IO"
documentation = "https://docs.rs/memmap2"
readme = "README.md"
keywords = [
"mmap",
"memory-map",
"io",
"file",
]
license = "MIT OR Apache-2.0"
repository = "https://github.com/RazrFalcon/memmap2-rs"
[dependencies.stable_deref_trait]
version = "1.0"
optional = true
[dev-dependencies.owning_ref]
version = "0.4.1"
[dev-dependencies.tempfile]
version = "3"
[target."cfg(unix)".dependencies.libc]
version = "0.2.143"
memmap2-0.9.3/Cargo.toml.orig 0000644 0000000 0000000 00000001100 10461020230 0014052 0 ustar 0000000 0000000 [package]
name = "memmap2"
version = "0.9.3"
authors = ["Dan Burkert ", "Yevhenii Reizner "]
license = "MIT OR Apache-2.0"
repository = "https://github.com/RazrFalcon/memmap2-rs"
documentation = "https://docs.rs/memmap2"
description = "Cross-platform Rust API for memory-mapped file IO"
keywords = ["mmap", "memory-map", "io", "file"]
edition = "2018"
[dependencies]
stable_deref_trait = { version = "1.0", optional = true }
[target.'cfg(unix)'.dependencies]
libc = "0.2.143"
[dev-dependencies]
tempfile = "3"
owning_ref = "0.4.1"
memmap2-0.9.3/LICENSE-APACHE 0000644 0000000 0000000 00000025123 10461020230 0013122 0 ustar 0000000 0000000 Apache License
Version 2.0, January 2004
http://www.apache.org/licenses/
TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
1. Definitions.
"License" shall mean the terms and conditions for use, reproduction,
and distribution as defined by Sections 1 through 9 of this document.
"Licensor" shall mean the copyright owner or entity authorized by
the copyright owner that is granting the License.
"Legal Entity" shall mean the union of the acting entity and all
other entities that control, are controlled by, or are under common
control with that entity. For the purposes of this definition,
"control" means (i) the power, direct or indirect, to cause the
direction or management of such entity, whether by contract or
otherwise, or (ii) ownership of fifty percent (50%) or more of the
outstanding shares, or (iii) beneficial ownership of such entity.
"You" (or "Your") shall mean an individual or Legal Entity
exercising permissions granted by this License.
"Source" form shall mean the preferred form for making modifications,
including but not limited to software source code, documentation
source, and configuration files.
"Object" form shall mean any form resulting from mechanical
transformation or translation of a Source form, including but
not limited to compiled object code, generated documentation,
and conversions to other media types.
"Work" shall mean the work of authorship, whether in Source or
Object form, made available under the License, as indicated by a
copyright notice that is included in or attached to the work
(an example is provided in the Appendix below).
"Derivative Works" shall mean any work, whether in Source or Object
form, that is based on (or derived from) the Work and for which the
editorial revisions, annotations, elaborations, or other modifications
represent, as a whole, an original work of authorship. For the purposes
of this License, Derivative Works shall not include works that remain
separable from, or merely link (or bind by name) to the interfaces of,
the Work and Derivative Works thereof.
"Contribution" shall mean any work of authorship, including
the original version of the Work and any modifications or additions
to that Work or Derivative Works thereof, that is intentionally
submitted to Licensor for inclusion in the Work by the copyright owner
or by an individual or Legal Entity authorized to submit on behalf of
the copyright owner. For the purposes of this definition, "submitted"
means any form of electronic, verbal, or written communication sent
to the Licensor or its representatives, including but not limited to
communication on electronic mailing lists, source code control systems,
and issue tracking systems that are managed by, or on behalf of, the
Licensor for the purpose of discussing and improving the Work, but
excluding communication that is conspicuously marked or otherwise
designated in writing by the copyright owner as "Not a Contribution."
"Contributor" shall mean Licensor and any individual or Legal Entity
on behalf of whom a Contribution has been received by Licensor and
subsequently incorporated within the Work.
2. Grant of Copyright License. Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
copyright license to reproduce, prepare Derivative Works of,
publicly display, publicly perform, sublicense, and distribute the
Work and such Derivative Works in Source or Object form.
3. Grant of Patent License. Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
(except as stated in this section) patent license to make, have made,
use, offer to sell, sell, import, and otherwise transfer the Work,
where such license applies only to those patent claims licensable
by such Contributor that are necessarily infringed by their
Contribution(s) alone or by combination of their Contribution(s)
with the Work to which such Contribution(s) was submitted. If You
institute patent litigation against any entity (including a
cross-claim or counterclaim in a lawsuit) alleging that the Work
or a Contribution incorporated within the Work constitutes direct
or contributory patent infringement, then any patent licenses
granted to You under this License for that Work shall terminate
as of the date such litigation is filed.
4. Redistribution. You may reproduce and distribute copies of the
Work or Derivative Works thereof in any medium, with or without
modifications, and in Source or Object form, provided that You
meet the following conditions:
(a) You must give any other recipients of the Work or
Derivative Works a copy of this License; and
(b) You must cause any modified files to carry prominent notices
stating that You changed the files; and
(c) You must retain, in the Source form of any Derivative Works
that You distribute, all copyright, patent, trademark, and
attribution notices from the Source form of the Work,
excluding those notices that do not pertain to any part of
the Derivative Works; and
(d) If the Work includes a "NOTICE" text file as part of its
distribution, then any Derivative Works that You distribute must
include a readable copy of the attribution notices contained
within such NOTICE file, excluding those notices that do not
pertain to any part of the Derivative Works, in at least one
of the following places: within a NOTICE text file distributed
as part of the Derivative Works; within the Source form or
documentation, if provided along with the Derivative Works; or,
within a display generated by the Derivative Works, if and
wherever such third-party notices normally appear. The contents
of the NOTICE file are for informational purposes only and
do not modify the License. You may add Your own attribution
notices within Derivative Works that You distribute, alongside
or as an addendum to the NOTICE text from the Work, provided
that such additional attribution notices cannot be construed
as modifying the License.
You may add Your own copyright statement to Your modifications and
may provide additional or different license terms and conditions
for use, reproduction, or distribution of Your modifications, or
for any such Derivative Works as a whole, provided Your use,
reproduction, and distribution of the Work otherwise complies with
the conditions stated in this License.
5. Submission of Contributions. Unless You explicitly state otherwise,
any Contribution intentionally submitted for inclusion in the Work
by You to the Licensor shall be under the terms and conditions of
this License, without any additional terms or conditions.
Notwithstanding the above, nothing herein shall supersede or modify
the terms of any separate license agreement you may have executed
with Licensor regarding such Contributions.
6. Trademarks. This License does not grant permission to use the trade
names, trademarks, service marks, or product names of the Licensor,
except as required for reasonable and customary use in describing the
origin of the Work and reproducing the content of the NOTICE file.
7. Disclaimer of Warranty. Unless required by applicable law or
agreed to in writing, Licensor provides the Work (and each
Contributor provides its Contributions) on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
implied, including, without limitation, any warranties or conditions
of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
PARTICULAR PURPOSE. You are solely responsible for determining the
appropriateness of using or redistributing the Work and assume any
risks associated with Your exercise of permissions under this License.
8. Limitation of Liability. In no event and under no legal theory,
whether in tort (including negligence), contract, or otherwise,
unless required by applicable law (such as deliberate and grossly
negligent acts) or agreed to in writing, shall any Contributor be
liable to You for damages, including any direct, indirect, special,
incidental, or consequential damages of any character arising as a
result of this License or out of the use or inability to use the
Work (including but not limited to damages for loss of goodwill,
work stoppage, computer failure or malfunction, or any and all
other commercial damages or losses), even if such Contributor
has been advised of the possibility of such damages.
9. Accepting Warranty or Additional Liability. While redistributing
the Work or Derivative Works thereof, You may choose to offer,
and charge a fee for, acceptance of support, warranty, indemnity,
or other liability obligations and/or rights consistent with this
License. However, in accepting such obligations, You may act only
on Your own behalf and on Your sole responsibility, not on behalf
of any other Contributor, and only if You agree to indemnify,
defend, and hold each Contributor harmless for any liability
incurred by, or claims asserted against, such Contributor by reason
of your accepting any such warranty or additional liability.
END OF TERMS AND CONDITIONS
APPENDIX: How to apply the Apache License to your work.
To apply the Apache License to your work, attach the following
boilerplate notice, with the fields enclosed by brackets "[]"
replaced with your own identifying information. (Don't include
the brackets!) The text should be enclosed in the appropriate
comment syntax for the file format. We also recommend that a
file or class name and description of purpose be included on the
same "printed page" as the copyright notice for easier
identification within third-party archives.
Copyright [2015] [Dan Burkert]
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
memmap2-0.9.3/LICENSE-MIT 0000644 0000000 0000000 00000002103 10461020230 0012623 0 ustar 0000000 0000000 Copyright (c) 2020 Yevhenii Reizner
Copyright (c) 2015 Dan Burkert
Permission is hereby granted, free of charge, to any
person obtaining a copy of this software and associated
documentation files (the "Software"), to deal in the
Software without restriction, including without
limitation the rights to use, copy, modify, merge,
publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software
is furnished to do so, subject to the following
conditions:
The above copyright notice and this permission notice
shall be included in all copies or substantial portions
of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.
memmap2-0.9.3/README.md 0000644 0000000 0000000 00000002224 10461020230 0012452 0 ustar 0000000 0000000 # memmap2

[](https://crates.io/crates/memmap2)
[](https://docs.rs/memmap2)
[](https://www.rust-lang.org)
A Rust library for cross-platform memory mapped IO.
This is a **fork** of the [memmap-rs](https://github.com/danburkert/memmap-rs) crate.
## Features
- [x] file-backed memory maps
- [x] anonymous memory maps
- [x] synchronous and asynchronous flushing
- [x] copy-on-write memory maps
- [x] read-only memory maps
- [x] stack support (`MAP_STACK` on unix)
- [x] executable memory maps
- [x] huge page support (linux only)
A list of supported/tested targets can be found in [Actions](https://github.com/RazrFalcon/memmap2-rs/actions).
## License
`memmap2` is primarily distributed under the terms of both the MIT license and the
Apache License (Version 2.0).
See [LICENSE-APACHE](LICENSE-APACHE), [LICENSE-MIT](LICENSE-MIT) for details.
Copyright (c) 2020 Yevhenii Reizner
Copyright (c) 2015 Dan Burkert
memmap2-0.9.3/examples/cat.rs 0000644 0000000 0000000 00000001106 10461020230 0014124 0 ustar 0000000 0000000 extern crate memmap2;
use std::env;
use std::fs::File;
use std::io::{self, Write};
use memmap2::Mmap;
/// Output a file's contents to stdout. The file path must be provided as the first process
/// argument.
fn main() {
let path = env::args()
.nth(1)
.expect("supply a single path as the program argument");
let file = File::open(path).expect("failed to open the file");
let mmap = unsafe { Mmap::map(&file).expect("failed to map the file") };
io::stdout()
.write_all(&mmap[..])
.expect("failed to output the file contents");
}
memmap2-0.9.3/src/advice.rs 0000644 0000000 0000000 00000042154 10461020230 0013571 0 ustar 0000000 0000000 /// Values supported by [`Mmap::advise`][crate::Mmap::advise] and [`MmapMut::advise`][crate::MmapMut::advise] functions.
///
/// See [madvise()](https://man7.org/linux/man-pages/man2/madvise.2.html) map page.
#[repr(i32)]
#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
pub enum Advice {
/// **MADV_NORMAL**
///
/// No special treatment. This is the default.
Normal = libc::MADV_NORMAL,
/// **MADV_RANDOM**
///
/// Expect page references in random order. (Hence, read
/// ahead may be less useful than normally.)
Random = libc::MADV_RANDOM,
/// **MADV_SEQUENTIAL**
///
/// Expect page references in sequential order. (Hence, pages
/// in the given range can be aggressively read ahead, and may
/// be freed soon after they are accessed.)
Sequential = libc::MADV_SEQUENTIAL,
/// **MADV_WILLNEED**
///
/// Expect access in the near future. (Hence, it might be a
/// good idea to read some pages ahead.)
WillNeed = libc::MADV_WILLNEED,
/// **MADV_DONTFORK** - Linux only (since Linux 2.6.16)
///
/// Do not make the pages in this range available to the child
/// after a fork(2). This is useful to prevent copy-on-write
/// semantics from changing the physical location of a page if
/// the parent writes to it after a fork(2). (Such page
/// relocations cause problems for hardware that DMAs into the
/// page.)
#[cfg(target_os = "linux")]
DontFork = libc::MADV_DONTFORK,
/// **MADV_DOFORK** - Linux only (since Linux 2.6.16)
///
/// Undo the effect of MADV_DONTFORK, restoring the default
/// behavior, whereby a mapping is inherited across fork(2).
#[cfg(target_os = "linux")]
DoFork = libc::MADV_DOFORK,
/// **MADV_MERGEABLE** - Linux only (since Linux 2.6.32)
///
/// Enable Kernel Samepage Merging (KSM) for the pages in the
/// range specified by addr and length. The kernel regularly
/// scans those areas of user memory that have been marked as
/// mergeable, looking for pages with identical content.
/// These are replaced by a single write-protected page (which
/// is automatically copied if a process later wants to update
/// the content of the page). KSM merges only private
/// anonymous pages (see mmap(2)).
///
/// The KSM feature is intended for applications that generate
/// many instances of the same data (e.g., virtualization
/// systems such as KVM). It can consume a lot of processing
/// power; use with care. See the Linux kernel source file
/// Documentation/admin-guide/mm/ksm.rst for more details.
///
/// The MADV_MERGEABLE and MADV_UNMERGEABLE operations are
/// available only if the kernel was configured with
/// CONFIG_KSM.
#[cfg(target_os = "linux")]
Mergeable = libc::MADV_MERGEABLE,
/// **MADV_UNMERGEABLE** - Linux only (since Linux 2.6.32)
///
/// Undo the effect of an earlier MADV_MERGEABLE operation on
/// the specified address range; KSM unmerges whatever pages
/// it had merged in the address range specified by addr and
/// length.
#[cfg(target_os = "linux")]
Unmergeable = libc::MADV_UNMERGEABLE,
/// **MADV_HUGEPAGE** - Linux only (since Linux 2.6.38)
///
/// Enable Transparent Huge Pages (THP) for pages in the range
/// specified by addr and length. Currently, Transparent Huge
/// Pages work only with private anonymous pages (see
/// mmap(2)). The kernel will regularly scan the areas marked
/// as huge page candidates to replace them with huge pages.
/// The kernel will also allocate huge pages directly when the
/// region is naturally aligned to the huge page size (see
/// posix_memalign(2)).
///
/// This feature is primarily aimed at applications that use
/// large mappings of data and access large regions of that
/// memory at a time (e.g., virtualization systems such as
/// QEMU). It can very easily waste memory (e.g., a 2 MB
/// mapping that only ever accesses 1 byte will result in 2 MB
/// of wired memory instead of one 4 KB page). See the Linux
/// kernel source file
/// Documentation/admin-guide/mm/transhuge.rst for more
/// details.
///
/// Most common kernels configurations provide MADV_HUGEPAGE-
/// style behavior by default, and thus MADV_HUGEPAGE is
/// normally not necessary. It is mostly intended for
/// embedded systems, where MADV_HUGEPAGE-style behavior may
/// not be enabled by default in the kernel. On such systems,
/// this flag can be used in order to selectively enable THP.
/// Whenever MADV_HUGEPAGE is used, it should always be in
/// regions of memory with an access pattern that the
/// developer knows in advance won't risk to increase the
/// memory footprint of the application when transparent
/// hugepages are enabled.
///
/// The MADV_HUGEPAGE and MADV_NOHUGEPAGE operations are
/// available only if the kernel was configured with
/// CONFIG_TRANSPARENT_HUGEPAGE.
#[cfg(target_os = "linux")]
HugePage = libc::MADV_HUGEPAGE,
/// **MADV_NOHUGEPAGE** - Linux only (since Linux 2.6.38)
///
/// Ensures that memory in the address range specified by addr
/// and length will not be backed by transparent hugepages.
#[cfg(target_os = "linux")]
NoHugePage = libc::MADV_NOHUGEPAGE,
/// **MADV_DONTDUMP** - Linux only (since Linux 3.4)
///
/// Exclude from a core dump those pages in the range
/// specified by addr and length. This is useful in
/// applications that have large areas of memory that are
/// known not to be useful in a core dump. The effect of
/// **MADV_DONTDUMP** takes precedence over the bit mask that is
/// set via the `/proc/[pid]/coredump_filter` file (see
/// core(5)).
#[cfg(target_os = "linux")]
DontDump = libc::MADV_DONTDUMP,
/// **MADV_DODUMP** - Linux only (since Linux 3.4)
///
/// Undo the effect of an earlier MADV_DONTDUMP.
#[cfg(target_os = "linux")]
DoDump = libc::MADV_DODUMP,
/// **MADV_HWPOISON** - Linux only (since Linux 2.6.32)
///
/// Poison the pages in the range specified by addr and length
/// and handle subsequent references to those pages like a
/// hardware memory corruption. This operation is available
/// only for privileged (CAP_SYS_ADMIN) processes. This
/// operation may result in the calling process receiving a
/// SIGBUS and the page being unmapped.
///
/// This feature is intended for testing of memory error-
/// handling code; it is available only if the kernel was
/// configured with CONFIG_MEMORY_FAILURE.
#[cfg(target_os = "linux")]
HwPoison = libc::MADV_HWPOISON,
/// **MADV_POPULATE_READ** - Linux only (since Linux 5.14)
///
/// Populate (prefault) page tables readable, faulting in all
/// pages in the range just as if manually reading from each
/// page; however, avoid the actual memory access that would have
/// been performed after handling the fault.
///
/// In contrast to MAP_POPULATE, MADV_POPULATE_READ does not hide
/// errors, can be applied to (parts of) existing mappings and
/// will always populate (prefault) page tables readable. One
/// example use case is prefaulting a file mapping, reading all
/// file content from disk; however, pages won't be dirtied and
/// consequently won't have to be written back to disk when
/// evicting the pages from memory.
///
/// Depending on the underlying mapping, map the shared zeropage,
/// preallocate memory or read the underlying file; files with
/// holes might or might not preallocate blocks. If populating
/// fails, a SIGBUS signal is not generated; instead, an error is
/// returned.
///
/// If MADV_POPULATE_READ succeeds, all page tables have been
/// populated (prefaulted) readable once. If MADV_POPULATE_READ
/// fails, some page tables might have been populated.
///
/// MADV_POPULATE_READ cannot be applied to mappings without read
/// permissions and special mappings, for example, mappings
/// marked with kernel-internal flags such as VM_PFNMAP or VM_IO,
/// or secret memory regions created using memfd_secret(2).
///
/// Note that with MADV_POPULATE_READ, the process can be killed
/// at any moment when the system runs out of memory.
#[cfg(target_os = "linux")]
PopulateRead = libc::MADV_POPULATE_READ,
/// **MADV_POPULATE_WRITE** - Linux only (since Linux 5.14)
///
/// Populate (prefault) page tables writable, faulting in all
/// pages in the range just as if manually writing to each each
/// page; however, avoid the actual memory access that would have
/// been performed after handling the fault.
///
/// In contrast to MAP_POPULATE, MADV_POPULATE_WRITE does not
/// hide errors, can be applied to (parts of) existing mappings
/// and will always populate (prefault) page tables writable.
/// One example use case is preallocating memory, breaking any
/// CoW (Copy on Write).
///
/// Depending on the underlying mapping, preallocate memory or
/// read the underlying file; files with holes will preallocate
/// blocks. If populating fails, a SIGBUS signal is not gener‐
/// ated; instead, an error is returned.
///
/// If MADV_POPULATE_WRITE succeeds, all page tables have been
/// populated (prefaulted) writable once. If MADV_POPULATE_WRITE
/// fails, some page tables might have been populated.
///
/// MADV_POPULATE_WRITE cannot be applied to mappings without
/// write permissions and special mappings, for example, mappings
/// marked with kernel-internal flags such as VM_PFNMAP or VM_IO,
/// or secret memory regions created using memfd_secret(2).
///
/// Note that with MADV_POPULATE_WRITE, the process can be killed
/// at any moment when the system runs out of memory.
#[cfg(target_os = "linux")]
PopulateWrite = libc::MADV_POPULATE_WRITE,
/// **MADV_ZERO_WIRED_PAGES** - Darwin only
///
/// Indicates that the application would like the wired pages in this address range to be
/// zeroed out if the address range is deallocated without first unwiring the pages (i.e.
/// a munmap(2) without a preceding munlock(2) or the application quits). This is used
/// with madvise() system call.
#[cfg(any(target_os = "macos", target_os = "ios"))]
ZeroWiredPages = libc::MADV_ZERO_WIRED_PAGES,
}
/// Values supported by [`Mmap::unsafe_advise`][crate::Mmap::unsafe_advise] and [`MmapMut::unsafe_advise`][crate::MmapMut::unsafe_advise] functions.
///
/// These flags can be passed to the [madvise (2)][man_page] system call
/// and effects on the mapped pages which are conceptually writes,
/// i.e. the change the observable contents of these pages which
/// implies undefined behaviour if the mapping is still borrowed.
///
/// Hence, these potentially unsafe flags must be used with the unsafe
/// methods and the programmer has to justify that the code
/// does not keep any borrows of the mapping active while the mapped pages
/// are updated by the kernel's memory management subsystem.
///
/// [man_page]: https://man7.org/linux/man-pages/man2/madvise.2.html
#[repr(i32)]
#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
pub enum UncheckedAdvice {
/// **MADV_DONTNEED**
///
/// Do not expect access in the near future. (For the time
/// being, the application is finished with the given range,
/// so the kernel can free resources associated with it.)
///
/// After a successful MADV_DONTNEED operation, the semantics
/// of memory access in the specified region are changed:
/// subsequent accesses of pages in the range will succeed,
/// but will result in either repopulating the memory contents
/// from the up-to-date contents of the underlying mapped file
/// (for shared file mappings, shared anonymous mappings, and
/// shmem-based techniques such as System V shared memory
/// segments) or zero-fill-on-demand pages for anonymous
/// private mappings.
///
/// Note that, when applied to shared mappings, MADV_DONTNEED
/// might not lead to immediate freeing of the pages in the
/// range. The kernel is free to delay freeing the pages
/// until an appropriate moment. The resident set size (RSS)
/// of the calling process will be immediately reduced
/// however.
///
/// **MADV_DONTNEED** cannot be applied to locked pages, Huge TLB
/// pages, or VM_PFNMAP pages. (Pages marked with the kernel-
/// internal VM_PFNMAP flag are special memory areas that are
/// not managed by the virtual memory subsystem. Such pages
/// are typically created by device drivers that map the pages
/// into user space.)
///
/// # Safety
///
/// Using the returned value with conceptually write to the
/// mapped pages, i.e. borrowing the mapping when the pages
/// are freed results in undefined behaviour.
DontNeed = libc::MADV_DONTNEED,
//
// The rest are Linux-specific
//
/// **MADV_FREE** - Linux (since Linux 4.5) and Darwin
///
/// The application no longer requires the pages in the range
/// specified by addr and len. The kernel can thus free these
/// pages, but the freeing could be delayed until memory
/// pressure occurs. For each of the pages that has been
/// marked to be freed but has not yet been freed, the free
/// operation will be canceled if the caller writes into the
/// page. After a successful MADV_FREE operation, any stale
/// data (i.e., dirty, unwritten pages) will be lost when the
/// kernel frees the pages. However, subsequent writes to
/// pages in the range will succeed and then kernel cannot
/// free those dirtied pages, so that the caller can always
/// see just written data. If there is no subsequent write,
/// the kernel can free the pages at any time. Once pages in
/// the range have been freed, the caller will see zero-fill-
/// on-demand pages upon subsequent page references.
///
/// The MADV_FREE operation can be applied only to private
/// anonymous pages (see mmap(2)). In Linux before version
/// 4.12, when freeing pages on a swapless system, the pages
/// in the given range are freed instantly, regardless of
/// memory pressure.
///
/// # Safety
///
/// Using the returned value with conceptually write to the
/// mapped pages, i.e. borrowing the mapping while the pages
/// are still being freed results in undefined behaviour.
#[cfg(any(target_os = "linux", target_os = "macos", target_os = "ios"))]
Free = libc::MADV_FREE,
/// **MADV_REMOVE** - Linux only (since Linux 2.6.16)
///
/// Free up a given range of pages and its associated backing
/// store. This is equivalent to punching a hole in the
/// corresponding byte range of the backing store (see
/// fallocate(2)). Subsequent accesses in the specified
/// address range will see bytes containing zero.
///
/// The specified address range must be mapped shared and
/// writable. This flag cannot be applied to locked pages,
/// Huge TLB pages, or VM_PFNMAP pages.
///
/// In the initial implementation, only tmpfs(5) was supported
/// **MADV_REMOVE**; but since Linux 3.5, any filesystem which
/// supports the fallocate(2) FALLOC_FL_PUNCH_HOLE mode also
/// supports MADV_REMOVE. Hugetlbfs fails with the error
/// EINVAL and other filesystems fail with the error
/// EOPNOTSUPP.
///
/// # Safety
///
/// Using the returned value with conceptually write to the
/// mapped pages, i.e. borrowing the mapping when the pages
/// are freed results in undefined behaviour.
#[cfg(target_os = "linux")]
Remove = libc::MADV_REMOVE,
/// **MADV_FREE_REUSABLE** - Darwin only
///
/// Behaves like **MADV_FREE**, but the freed pages are accounted for in the RSS of the process.
///
/// # Safety
///
/// Using the returned value with conceptually write to the
/// mapped pages, i.e. borrowing the mapping while the pages
/// are still being freed results in undefined behaviour.
#[cfg(any(target_os = "macos", target_os = "ios"))]
FreeReusable = libc::MADV_FREE_REUSABLE,
/// **MADV_FREE_REUSE** - Darwin only
///
/// Marks a memory region previously freed by **MADV_FREE_REUSABLE** as non-reusable, accounts
/// for the pages in the RSS of the process. Pages that have been freed will be replaced by
/// zero-filled pages on demand, other pages will be left as is.
///
/// # Safety
///
/// Using the returned value with conceptually write to the
/// mapped pages, i.e. borrowing the mapping while the pages
/// are still being freed results in undefined behaviour.
#[cfg(any(target_os = "macos", target_os = "ios"))]
FreeReuse = libc::MADV_FREE_REUSE,
}
// Future expansion:
// MADV_SOFT_OFFLINE (since Linux 2.6.33)
// MADV_WIPEONFORK (since Linux 4.14)
// MADV_KEEPONFORK (since Linux 4.14)
// MADV_COLD (since Linux 5.4)
// MADV_PAGEOUT (since Linux 5.4)
memmap2-0.9.3/src/lib.rs 0000644 0000000 0000000 00000210471 10461020230 0013103 0 ustar 0000000 0000000 //! A cross-platform Rust API for memory mapped buffers.
//!
//! The core functionality is provided by either [`Mmap`] or [`MmapMut`],
//! which correspond to mapping a [`File`] to a [`&[u8]`](https://doc.rust-lang.org/std/primitive.slice.html)
//! or [`&mut [u8]`](https://doc.rust-lang.org/std/primitive.slice.html)
//! respectively. Both function by dereferencing to a slice, allowing the
//! [`Mmap`]/[`MmapMut`] to be used in the same way you would the equivalent slice
//! types.
//!
//! [`File`]: std::fs::File
//!
//! # Examples
//!
//! For simple cases [`Mmap`] can be used directly:
//!
//! ```
//! use std::fs::File;
//! use std::io::Read;
//!
//! use memmap2::Mmap;
//!
//! # fn main() -> std::io::Result<()> {
//! let mut file = File::open("LICENSE-APACHE")?;
//!
//! let mut contents = Vec::new();
//! file.read_to_end(&mut contents)?;
//!
//! let mmap = unsafe { Mmap::map(&file)? };
//!
//! assert_eq!(&contents[..], &mmap[..]);
//! # Ok(())
//! # }
//! ```
//!
//! However for cases which require configuration of the mapping, then
//! you can use [`MmapOptions`] in order to further configure a mapping
//! before you create it.
#![allow(clippy::len_without_is_empty, clippy::missing_safety_doc)]
#[cfg_attr(unix, path = "unix.rs")]
#[cfg_attr(windows, path = "windows.rs")]
#[cfg_attr(not(any(unix, windows)), path = "stub.rs")]
mod os;
use crate::os::{file_len, MmapInner};
#[cfg(unix)]
mod advice;
#[cfg(unix)]
pub use crate::advice::{Advice, UncheckedAdvice};
use std::fmt;
#[cfg(not(any(unix, windows)))]
use std::fs::File;
use std::io::{Error, ErrorKind, Result};
use std::isize;
use std::mem;
use std::ops::{Deref, DerefMut};
#[cfg(unix)]
use std::os::unix::io::{AsRawFd, RawFd};
#[cfg(windows)]
use std::os::windows::io::{AsRawHandle, RawHandle};
use std::slice;
#[cfg(not(any(unix, windows)))]
pub struct MmapRawDescriptor<'a>(&'a File);
#[cfg(unix)]
pub struct MmapRawDescriptor(RawFd);
#[cfg(windows)]
pub struct MmapRawDescriptor(RawHandle);
pub trait MmapAsRawDesc {
fn as_raw_desc(&self) -> MmapRawDescriptor;
}
#[cfg(not(any(unix, windows)))]
impl MmapAsRawDesc for &File {
fn as_raw_desc(&self) -> MmapRawDescriptor {
MmapRawDescriptor(self)
}
}
#[cfg(unix)]
impl MmapAsRawDesc for RawFd {
fn as_raw_desc(&self) -> MmapRawDescriptor {
MmapRawDescriptor(*self)
}
}
#[cfg(unix)]
impl<'a, T> MmapAsRawDesc for &'a T
where
T: AsRawFd,
{
fn as_raw_desc(&self) -> MmapRawDescriptor {
MmapRawDescriptor(self.as_raw_fd())
}
}
#[cfg(windows)]
impl MmapAsRawDesc for RawHandle {
fn as_raw_desc(&self) -> MmapRawDescriptor {
MmapRawDescriptor(*self)
}
}
#[cfg(windows)]
impl<'a, T> MmapAsRawDesc for &'a T
where
T: AsRawHandle,
{
fn as_raw_desc(&self) -> MmapRawDescriptor {
MmapRawDescriptor(self.as_raw_handle())
}
}
/// A memory map builder, providing advanced options and flags for specifying memory map behavior.
///
/// `MmapOptions` can be used to create an anonymous memory map using [`map_anon()`], or a
/// file-backed memory map using one of [`map()`], [`map_mut()`], [`map_exec()`],
/// [`map_copy()`], or [`map_copy_read_only()`].
///
/// ## Safety
///
/// All file-backed memory map constructors are marked `unsafe` because of the potential for
/// *Undefined Behavior* (UB) using the map if the underlying file is subsequently modified, in or
/// out of process. Applications must consider the risk and take appropriate precautions when
/// using file-backed maps. Solutions such as file permissions, locks or process-private (e.g.
/// unlinked) files exist but are platform specific and limited.
///
/// [`map_anon()`]: MmapOptions::map_anon()
/// [`map()`]: MmapOptions::map()
/// [`map_mut()`]: MmapOptions::map_mut()
/// [`map_exec()`]: MmapOptions::map_exec()
/// [`map_copy()`]: MmapOptions::map_copy()
/// [`map_copy_read_only()`]: MmapOptions::map_copy_read_only()
#[derive(Clone, Debug, Default)]
pub struct MmapOptions {
offset: u64,
len: Option,
huge: Option,
stack: bool,
populate: bool,
}
impl MmapOptions {
/// Creates a new set of options for configuring and creating a memory map.
///
/// # Example
///
/// ```
/// use memmap2::{MmapMut, MmapOptions};
/// # use std::io::Result;
///
/// # fn main() -> Result<()> {
/// // Create a new memory map builder.
/// let mut mmap_options = MmapOptions::new();
///
/// // Configure the memory map builder using option setters, then create
/// // a memory map using one of `mmap_options.map_anon`, `mmap_options.map`,
/// // `mmap_options.map_mut`, `mmap_options.map_exec`, or `mmap_options.map_copy`:
/// let mut mmap: MmapMut = mmap_options.len(36).map_anon()?;
///
/// // Use the memory map:
/// mmap.copy_from_slice(b"...data to copy to the memory map...");
/// # Ok(())
/// # }
/// ```
pub fn new() -> MmapOptions {
MmapOptions::default()
}
/// Configures the memory map to start at byte `offset` from the beginning of the file.
///
/// This option has no effect on anonymous memory maps.
///
/// By default, the offset is 0.
///
/// # Example
///
/// ```
/// use memmap2::MmapOptions;
/// use std::fs::File;
///
/// # fn main() -> std::io::Result<()> {
/// let mmap = unsafe {
/// MmapOptions::new()
/// .offset(30)
/// .map(&File::open("LICENSE-APACHE")?)?
/// };
/// assert_eq!(&b"Apache License"[..],
/// &mmap[..14]);
/// # Ok(())
/// # }
/// ```
pub fn offset(&mut self, offset: u64) -> &mut Self {
self.offset = offset;
self
}
/// Configures the created memory mapped buffer to be `len` bytes long.
///
/// This option is mandatory for anonymous memory maps.
///
/// For file-backed memory maps, the length will default to the file length.
///
/// # Example
///
/// ```
/// use memmap2::MmapOptions;
/// use std::fs::File;
///
/// # fn main() -> std::io::Result<()> {
/// let mmap = unsafe {
/// MmapOptions::new()
/// .len(9)
/// .map(&File::open("README.md")?)?
/// };
/// assert_eq!(&b"# memmap2"[..], &mmap[..]);
/// # Ok(())
/// # }
/// ```
pub fn len(&mut self, len: usize) -> &mut Self {
self.len = Some(len);
self
}
/// Returns the configured length, or the length of the provided file.
fn get_len(&self, file: &T) -> Result {
self.len.map(Ok).unwrap_or_else(|| {
let desc = file.as_raw_desc();
let file_len = file_len(desc.0)?;
if file_len < self.offset {
return Err(Error::new(
ErrorKind::InvalidData,
"memory map offset is larger than length",
));
}
let len = file_len - self.offset;
// Rust's slice cannot be larger than isize::MAX.
// See https://doc.rust-lang.org/std/slice/fn.from_raw_parts.html
//
// This is not a problem on 64-bit targets, but on 32-bit one
// having a file or an anonymous mapping larger than 2GB is quite normal
// and we have to prevent it.
//
// The code below is essentially the same as in Rust's std:
// https://github.com/rust-lang/rust/blob/db78ab70a88a0a5e89031d7ee4eccec835dcdbde/library/alloc/src/raw_vec.rs#L495
if mem::size_of::() < 8 && len > isize::MAX as u64 {
return Err(Error::new(
ErrorKind::InvalidData,
"memory map length overflows isize",
));
}
Ok(len as usize)
})
}
/// Configures the anonymous memory map to be suitable for a process or thread stack.
///
/// This option corresponds to the `MAP_STACK` flag on Linux. It has no effect on Windows.
///
/// This option has no effect on file-backed memory maps.
///
/// # Example
///
/// ```
/// use memmap2::MmapOptions;
///
/// # fn main() -> std::io::Result<()> {
/// let stack = MmapOptions::new().stack().len(4096).map_anon();
/// # Ok(())
/// # }
/// ```
pub fn stack(&mut self) -> &mut Self {
self.stack = true;
self
}
/// Configures the anonymous memory map to be allocated using huge pages.
///
/// This option corresponds to the `MAP_HUGETLB` flag on Linux. It has no effect on Windows.
///
/// The size of the requested page can be specified in page bits. If not provided, the system
/// default is requested. The requested length should be a multiple of this, or the mapping
/// will fail.
///
/// This option has no effect on file-backed memory maps.
///
/// # Example
///
/// ```
/// use memmap2::MmapOptions;
///
/// # fn main() -> std::io::Result<()> {
/// let stack = MmapOptions::new().huge(Some(21)).len(2*1024*1024).map_anon();
/// # Ok(())
/// # }
/// ```
pub fn huge(&mut self, page_bits: Option) -> &mut Self {
self.huge = Some(page_bits.unwrap_or(0));
self
}
/// Populate (prefault) page tables for a mapping.
///
/// For a file mapping, this causes read-ahead on the file. This will help to reduce blocking on page faults later.
///
/// This option corresponds to the `MAP_POPULATE` flag on Linux. It has no effect on Windows.
///
/// # Example
///
/// ```
/// use memmap2::MmapOptions;
/// use std::fs::File;
///
/// # fn main() -> std::io::Result<()> {
/// let file = File::open("LICENSE-MIT")?;
///
/// let mmap = unsafe {
/// MmapOptions::new().populate().map(&file)?
/// };
///
/// assert_eq!(&b"Copyright"[..], &mmap[..9]);
/// # Ok(())
/// # }
/// ```
pub fn populate(&mut self) -> &mut Self {
self.populate = true;
self
}
/// Creates a read-only memory map backed by a file.
///
/// # Errors
///
/// This method returns an error when the underlying system call fails, which can happen for a
/// variety of reasons, such as when the file is not open with read permissions.
///
/// # Example
///
/// ```
/// use memmap2::MmapOptions;
/// use std::fs::File;
/// use std::io::Read;
///
/// # fn main() -> std::io::Result<()> {
/// let mut file = File::open("LICENSE-APACHE")?;
///
/// let mut contents = Vec::new();
/// file.read_to_end(&mut contents)?;
///
/// let mmap = unsafe {
/// MmapOptions::new().map(&file)?
/// };
///
/// assert_eq!(&contents[..], &mmap[..]);
/// # Ok(())
/// # }
/// ```
pub unsafe fn map(&self, file: T) -> Result {
let desc = file.as_raw_desc();
MmapInner::map(self.get_len(&file)?, desc.0, self.offset, self.populate)
.map(|inner| Mmap { inner })
}
/// Creates a readable and executable memory map backed by a file.
///
/// # Errors
///
/// This method returns an error when the underlying system call fails, which can happen for a
/// variety of reasons, such as when the file is not open with read permissions.
pub unsafe fn map_exec(&self, file: T) -> Result {
let desc = file.as_raw_desc();
MmapInner::map_exec(self.get_len(&file)?, desc.0, self.offset, self.populate)
.map(|inner| Mmap { inner })
}
/// Creates a writeable memory map backed by a file.
///
/// # Errors
///
/// This method returns an error when the underlying system call fails, which can happen for a
/// variety of reasons, such as when the file is not open with read and write permissions.
///
/// # Example
///
/// ```
/// # extern crate memmap2;
/// # extern crate tempfile;
/// #
/// use std::fs::OpenOptions;
/// use std::path::PathBuf;
///
/// use memmap2::MmapOptions;
/// #
/// # fn main() -> std::io::Result<()> {
/// # let tempdir = tempfile::tempdir()?;
/// let path: PathBuf = /* path to file */
/// # tempdir.path().join("map_mut");
/// let file = OpenOptions::new().read(true).write(true).create(true).open(&path)?;
/// file.set_len(13)?;
///
/// let mut mmap = unsafe {
/// MmapOptions::new().map_mut(&file)?
/// };
///
/// mmap.copy_from_slice(b"Hello, world!");
/// # Ok(())
/// # }
/// ```
pub unsafe fn map_mut(&self, file: T) -> Result {
let desc = file.as_raw_desc();
MmapInner::map_mut(self.get_len(&file)?, desc.0, self.offset, self.populate)
.map(|inner| MmapMut { inner })
}
/// Creates a copy-on-write memory map backed by a file.
///
/// Data written to the memory map will not be visible by other processes,
/// and will not be carried through to the underlying file.
///
/// # Errors
///
/// This method returns an error when the underlying system call fails, which can happen for a
/// variety of reasons, such as when the file is not open with writable permissions.
///
/// # Example
///
/// ```
/// use memmap2::MmapOptions;
/// use std::fs::File;
/// use std::io::Write;
///
/// # fn main() -> std::io::Result<()> {
/// let file = File::open("LICENSE-APACHE")?;
/// let mut mmap = unsafe { MmapOptions::new().map_copy(&file)? };
/// (&mut mmap[..]).write_all(b"Hello, world!")?;
/// # Ok(())
/// # }
/// ```
pub unsafe fn map_copy(&self, file: T) -> Result {
let desc = file.as_raw_desc();
MmapInner::map_copy(self.get_len(&file)?, desc.0, self.offset, self.populate)
.map(|inner| MmapMut { inner })
}
/// Creates a copy-on-write read-only memory map backed by a file.
///
/// # Errors
///
/// This method returns an error when the underlying system call fails, which can happen for a
/// variety of reasons, such as when the file is not open with read permissions.
///
/// # Example
///
/// ```
/// use memmap2::MmapOptions;
/// use std::fs::File;
/// use std::io::Read;
///
/// # fn main() -> std::io::Result<()> {
/// let mut file = File::open("README.md")?;
///
/// let mut contents = Vec::new();
/// file.read_to_end(&mut contents)?;
///
/// let mmap = unsafe {
/// MmapOptions::new().map_copy_read_only(&file)?
/// };
///
/// assert_eq!(&contents[..], &mmap[..]);
/// # Ok(())
/// # }
/// ```
pub unsafe fn map_copy_read_only(&self, file: T) -> Result {
let desc = file.as_raw_desc();
MmapInner::map_copy_read_only(self.get_len(&file)?, desc.0, self.offset, self.populate)
.map(|inner| Mmap { inner })
}
/// Creates an anonymous memory map.
///
/// The memory map length should be configured using [`MmapOptions::len()`]
/// before creating an anonymous memory map, otherwise a zero-length mapping
/// will be crated.
///
/// # Errors
///
/// This method returns an error when the underlying system call fails or
/// when `len > isize::MAX`.
pub fn map_anon(&self) -> Result {
let len = self.len.unwrap_or(0);
// See get_len() for details.
if mem::size_of::() < 8 && len > isize::MAX as usize {
return Err(Error::new(
ErrorKind::InvalidData,
"memory map length overflows isize",
));
}
MmapInner::map_anon(len, self.stack, self.populate, self.huge)
.map(|inner| MmapMut { inner })
}
/// Creates a raw memory map.
///
/// # Errors
///
/// This method returns an error when the underlying system call fails, which can happen for a
/// variety of reasons, such as when the file is not open with read and write permissions.
pub fn map_raw(&self, file: T) -> Result {
let desc = file.as_raw_desc();
MmapInner::map_mut(self.get_len(&file)?, desc.0, self.offset, self.populate)
.map(|inner| MmapRaw { inner })
}
/// Creates a read-only raw memory map
///
/// This is primarily useful to avoid intermediate `Mmap` instances when
/// read-only access to files modified elsewhere are required.
///
/// # Errors
///
/// This method returns an error when the underlying system call fails
pub fn map_raw_read_only(&self, file: T) -> Result {
let desc = file.as_raw_desc();
MmapInner::map(self.get_len(&file)?, desc.0, self.offset, self.populate)
.map(|inner| MmapRaw { inner })
}
}
/// A handle to an immutable memory mapped buffer.
///
/// A `Mmap` may be backed by a file, or it can be anonymous map, backed by volatile memory. Use
/// [`MmapOptions`] or [`map()`] to create a file-backed memory map. To create an immutable
/// anonymous memory map, first create a mutable anonymous memory map, and then make it immutable
/// with [`MmapMut::make_read_only()`].
///
/// A file backed `Mmap` is created by `&File` reference, and will remain valid even after the
/// `File` is dropped. In other words, the `Mmap` handle is completely independent of the `File`
/// used to create it. For consistency, on some platforms this is achieved by duplicating the
/// underlying file handle. The memory will be unmapped when the `Mmap` handle is dropped.
///
/// Dereferencing and accessing the bytes of the buffer may result in page faults (e.g. swapping
/// the mapped pages into physical memory) though the details of this are platform specific.
///
/// `Mmap` is [`Sync`] and [`Send`].
///
/// ## Safety
///
/// All file-backed memory map constructors are marked `unsafe` because of the potential for
/// *Undefined Behavior* (UB) using the map if the underlying file is subsequently modified, in or
/// out of process. Applications must consider the risk and take appropriate precautions when using
/// file-backed maps. Solutions such as file permissions, locks or process-private (e.g. unlinked)
/// files exist but are platform specific and limited.
///
/// ## Example
///
/// ```
/// use memmap2::MmapOptions;
/// use std::io::Write;
/// use std::fs::File;
///
/// # fn main() -> std::io::Result<()> {
/// let file = File::open("README.md")?;
/// let mmap = unsafe { MmapOptions::new().map(&file)? };
/// assert_eq!(b"# memmap2", &mmap[0..9]);
/// # Ok(())
/// # }
/// ```
///
/// See [`MmapMut`] for the mutable version.
///
/// [`map()`]: Mmap::map()
pub struct Mmap {
inner: MmapInner,
}
impl Mmap {
/// Creates a read-only memory map backed by a file.
///
/// This is equivalent to calling `MmapOptions::new().map(file)`.
///
/// # Errors
///
/// This method returns an error when the underlying system call fails, which can happen for a
/// variety of reasons, such as when the file is not open with read permissions.
///
/// # Example
///
/// ```
/// use std::fs::File;
/// use std::io::Read;
///
/// use memmap2::Mmap;
///
/// # fn main() -> std::io::Result<()> {
/// let mut file = File::open("LICENSE-APACHE")?;
///
/// let mut contents = Vec::new();
/// file.read_to_end(&mut contents)?;
///
/// let mmap = unsafe { Mmap::map(&file)? };
///
/// assert_eq!(&contents[..], &mmap[..]);
/// # Ok(())
/// # }
/// ```
pub unsafe fn map(file: T) -> Result {
MmapOptions::new().map(file)
}
/// Transition the memory map to be writable.
///
/// If the memory map is file-backed, the file must have been opened with write permissions.
///
/// # Errors
///
/// This method returns an error when the underlying system call fails, which can happen for a
/// variety of reasons, such as when the file is not open with writable permissions.
///
/// # Example
///
/// ```
/// # extern crate memmap2;
/// # extern crate tempfile;
/// #
/// use memmap2::Mmap;
/// use std::ops::DerefMut;
/// use std::io::Write;
/// # use std::fs::OpenOptions;
///
/// # fn main() -> std::io::Result<()> {
/// # let tempdir = tempfile::tempdir()?;
/// let file = /* file opened with write permissions */
/// # OpenOptions::new()
/// # .read(true)
/// # .write(true)
/// # .create(true)
/// # .open(tempdir.path()
/// # .join("make_mut"))?;
/// # file.set_len(128)?;
/// let mmap = unsafe { Mmap::map(&file)? };
/// // ... use the read-only memory map ...
/// let mut mut_mmap = mmap.make_mut()?;
/// mut_mmap.deref_mut().write_all(b"hello, world!")?;
/// # Ok(())
/// # }
/// ```
pub fn make_mut(mut self) -> Result {
self.inner.make_mut()?;
Ok(MmapMut { inner: self.inner })
}
/// Advise OS how this memory map will be accessed.
///
/// Only supported on Unix.
///
/// See [madvise()](https://man7.org/linux/man-pages/man2/madvise.2.html) map page.
#[cfg(unix)]
pub fn advise(&self, advice: Advice) -> Result<()> {
self.inner
.advise(advice as libc::c_int, 0, self.inner.len())
}
/// Advise OS how this memory map will be accessed.
///
/// Used with the [unchecked flags][UncheckedAdvice]. Only supported on Unix.
///
/// See [madvise()](https://man7.org/linux/man-pages/man2/madvise.2.html) map page.
#[cfg(unix)]
pub unsafe fn unchecked_advise(&self, advice: UncheckedAdvice) -> Result<()> {
self.inner
.advise(advice as libc::c_int, 0, self.inner.len())
}
/// Advise OS how this range of memory map will be accessed.
///
/// Only supported on Unix.
///
/// The offset and length must be in the bounds of the memory map.
///
/// See [madvise()](https://man7.org/linux/man-pages/man2/madvise.2.html) map page.
#[cfg(unix)]
pub fn advise_range(&self, advice: Advice, offset: usize, len: usize) -> Result<()> {
self.inner.advise(advice as libc::c_int, offset, len)
}
/// Advise OS how this range of memory map will be accessed.
///
/// Used with the [unchecked flags][UncheckedAdvice]. Only supported on Unix.
///
/// The offset and length must be in the bounds of the memory map.
///
/// See [madvise()](https://man7.org/linux/man-pages/man2/madvise.2.html) map page.
#[cfg(unix)]
pub unsafe fn unchecked_advise_range(
&self,
advice: UncheckedAdvice,
offset: usize,
len: usize,
) -> Result<()> {
self.inner.advise(advice as libc::c_int, offset, len)
}
/// Lock the whole memory map into RAM. Only supported on Unix.
///
/// See [mlock()](https://man7.org/linux/man-pages/man2/mlock.2.html) map page.
#[cfg(unix)]
pub fn lock(&self) -> Result<()> {
self.inner.lock()
}
/// Unlock the whole memory map. Only supported on Unix.
///
/// See [munlock()](https://man7.org/linux/man-pages/man2/munlock.2.html) map page.
#[cfg(unix)]
pub fn unlock(&self) -> Result<()> {
self.inner.unlock()
}
/// Adjust the size of the memory mapping.
///
/// This will try to resize the memory mapping in place. If
/// [`RemapOptions::may_move`] is specified it will move the mapping if it
/// could not resize in place, otherwise it will error.
///
/// Only supported on Linux.
///
/// See the [`mremap(2)`] man page.
///
/// # Safety
///
/// Resizing the memory mapping beyond the end of the mapped file will
/// result in UB should you happen to access memory beyond the end of the
/// file.
///
/// [`mremap(2)`]: https://man7.org/linux/man-pages/man2/mremap.2.html
#[cfg(target_os = "linux")]
pub unsafe fn remap(&mut self, new_len: usize, options: RemapOptions) -> Result<()> {
self.inner.remap(new_len, options)
}
}
#[cfg(feature = "stable_deref_trait")]
unsafe impl stable_deref_trait::StableDeref for Mmap {}
impl Deref for Mmap {
type Target = [u8];
#[inline]
fn deref(&self) -> &[u8] {
unsafe { slice::from_raw_parts(self.inner.ptr(), self.inner.len()) }
}
}
impl AsRef<[u8]> for Mmap {
#[inline]
fn as_ref(&self) -> &[u8] {
self.deref()
}
}
impl fmt::Debug for Mmap {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
fmt.debug_struct("Mmap")
.field("ptr", &self.as_ptr())
.field("len", &self.len())
.finish()
}
}
/// A handle to a raw memory mapped buffer.
///
/// This struct never hands out references to its interior, only raw pointers.
/// This can be helpful when creating shared memory maps between untrusted processes.
pub struct MmapRaw {
inner: MmapInner,
}
impl MmapRaw {
/// Creates a writeable memory map backed by a file.
///
/// This is equivalent to calling `MmapOptions::new().map_raw(file)`.
///
/// # Errors
///
/// This method returns an error when the underlying system call fails, which can happen for a
/// variety of reasons, such as when the file is not open with read and write permissions.
pub fn map_raw(file: T) -> Result {
MmapOptions::new().map_raw(file)
}
/// Returns a raw pointer to the memory mapped file.
///
/// Before dereferencing this pointer, you have to make sure that the file has not been
/// truncated since the memory map was created.
/// Avoiding this will not introduce memory safety issues in Rust terms,
/// but will cause SIGBUS (or equivalent) signal.
#[inline]
pub fn as_ptr(&self) -> *const u8 {
self.inner.ptr()
}
/// Returns an unsafe mutable pointer to the memory mapped file.
///
/// Before dereferencing this pointer, you have to make sure that the file has not been
/// truncated since the memory map was created.
/// Avoiding this will not introduce memory safety issues in Rust terms,
/// but will cause SIGBUS (or equivalent) signal.
#[inline]
pub fn as_mut_ptr(&self) -> *mut u8 {
self.inner.ptr() as _
}
/// Returns the length in bytes of the memory map.
///
/// Note that truncating the file can cause the length to change (and render this value unusable).
#[inline]
pub fn len(&self) -> usize {
self.inner.len()
}
/// Flushes outstanding memory map modifications to disk.
///
/// When this method returns with a non-error result, all outstanding changes to a file-backed
/// memory map are guaranteed to be durably stored. The file's metadata (including last
/// modification timestamp) may not be updated.
///
/// # Example
///
/// ```
/// # extern crate memmap2;
/// # extern crate tempfile;
/// #
/// use std::fs::OpenOptions;
/// use std::io::Write;
/// use std::path::PathBuf;
/// use std::slice;
///
/// use memmap2::MmapRaw;
///
/// # fn main() -> std::io::Result<()> {
/// let tempdir = tempfile::tempdir()?;
/// let path: PathBuf = /* path to file */
/// # tempdir.path().join("flush");
/// let file = OpenOptions::new().read(true).write(true).create(true).open(&path)?;
/// file.set_len(128)?;
///
/// let mut mmap = unsafe { MmapRaw::map_raw(&file)? };
///
/// let mut memory = unsafe { slice::from_raw_parts_mut(mmap.as_mut_ptr(), 128) };
/// memory.write_all(b"Hello, world!")?;
/// mmap.flush()?;
/// # Ok(())
/// # }
/// ```
pub fn flush(&self) -> Result<()> {
let len = self.len();
self.inner.flush(0, len)
}
/// Asynchronously flushes outstanding memory map modifications to disk.
///
/// This method initiates flushing modified pages to durable storage, but it will not wait for
/// the operation to complete before returning. The file's metadata (including last
/// modification timestamp) may not be updated.
pub fn flush_async(&self) -> Result<()> {
let len = self.len();
self.inner.flush_async(0, len)
}
/// Flushes outstanding memory map modifications in the range to disk.
///
/// The offset and length must be in the bounds of the memory map.
///
/// When this method returns with a non-error result, all outstanding changes to a file-backed
/// memory in the range are guaranteed to be durable stored. The file's metadata (including
/// last modification timestamp) may not be updated. It is not guaranteed the only the changes
/// in the specified range are flushed; other outstanding changes to the memory map may be
/// flushed as well.
pub fn flush_range(&self, offset: usize, len: usize) -> Result<()> {
self.inner.flush(offset, len)
}
/// Asynchronously flushes outstanding memory map modifications in the range to disk.
///
/// The offset and length must be in the bounds of the memory map.
///
/// This method initiates flushing modified pages to durable storage, but it will not wait for
/// the operation to complete before returning. The file's metadata (including last
/// modification timestamp) may not be updated. It is not guaranteed that the only changes
/// flushed are those in the specified range; other outstanding changes to the memory map may
/// be flushed as well.
pub fn flush_async_range(&self, offset: usize, len: usize) -> Result<()> {
self.inner.flush_async(offset, len)
}
/// Advise OS how this memory map will be accessed.
///
/// Only supported on Unix.
///
/// See [madvise()](https://man7.org/linux/man-pages/man2/madvise.2.html) map page.
#[cfg(unix)]
pub fn advise(&self, advice: Advice) -> Result<()> {
self.inner
.advise(advice as libc::c_int, 0, self.inner.len())
}
/// Advise OS how this memory map will be accessed.
///
/// Used with the [unchecked flags][UncheckedAdvice]. Only supported on Unix.
///
/// See [madvise()](https://man7.org/linux/man-pages/man2/madvise.2.html) map page.
#[cfg(unix)]
pub unsafe fn unchecked_advise(&self, advice: UncheckedAdvice) -> Result<()> {
self.inner
.advise(advice as libc::c_int, 0, self.inner.len())
}
/// Advise OS how this range of memory map will be accessed.
///
/// The offset and length must be in the bounds of the memory map.
///
/// Only supported on Unix.
///
/// See [madvise()](https://man7.org/linux/man-pages/man2/madvise.2.html) map page.
#[cfg(unix)]
pub fn advise_range(&self, advice: Advice, offset: usize, len: usize) -> Result<()> {
self.inner.advise(advice as libc::c_int, offset, len)
}
/// Advise OS how this range of memory map will be accessed.
///
/// Used with the [unchecked flags][UncheckedAdvice]. Only supported on Unix.
///
/// The offset and length must be in the bounds of the memory map.
///
/// See [madvise()](https://man7.org/linux/man-pages/man2/madvise.2.html) map page.
#[cfg(unix)]
pub unsafe fn unchecked_advise_range(
&self,
advice: UncheckedAdvice,
offset: usize,
len: usize,
) -> Result<()> {
self.inner.advise(advice as libc::c_int, offset, len)
}
/// Lock the whole memory map into RAM. Only supported on Unix.
///
/// See [mlock()](https://man7.org/linux/man-pages/man2/mlock.2.html) map page.
#[cfg(unix)]
pub fn lock(&self) -> Result<()> {
self.inner.lock()
}
/// Unlock the whole memory map. Only supported on Unix.
///
/// See [munlock()](https://man7.org/linux/man-pages/man2/munlock.2.html) map page.
#[cfg(unix)]
pub fn unlock(&self) -> Result<()> {
self.inner.unlock()
}
/// Adjust the size of the memory mapping.
///
/// This will try to resize the memory mapping in place. If
/// [`RemapOptions::may_move`] is specified it will move the mapping if it
/// could not resize in place, otherwise it will error.
///
/// Only supported on Linux.
///
/// See the [`mremap(2)`] man page.
///
/// # Safety
///
/// Resizing the memory mapping beyond the end of the mapped file will
/// result in UB should you happen to access memory beyond the end of the
/// file.
///
/// [`mremap(2)`]: https://man7.org/linux/man-pages/man2/mremap.2.html
#[cfg(target_os = "linux")]
pub unsafe fn remap(&mut self, new_len: usize, options: RemapOptions) -> Result<()> {
self.inner.remap(new_len, options)
}
}
impl fmt::Debug for MmapRaw {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
fmt.debug_struct("MmapRaw")
.field("ptr", &self.as_ptr())
.field("len", &self.len())
.finish()
}
}
impl From for MmapRaw {
fn from(value: Mmap) -> Self {
Self { inner: value.inner }
}
}
impl From for MmapRaw {
fn from(value: MmapMut) -> Self {
Self { inner: value.inner }
}
}
/// A handle to a mutable memory mapped buffer.
///
/// A file-backed `MmapMut` buffer may be used to read from or write to a file. An anonymous
/// `MmapMut` buffer may be used any place that an in-memory byte buffer is needed. Use
/// [`MmapMut::map_mut()`] and [`MmapMut::map_anon()`] to create a mutable memory map of the
/// respective types, or [`MmapOptions::map_mut()`] and [`MmapOptions::map_anon()`] if non-default
/// options are required.
///
/// A file backed `MmapMut` is created by `&File` reference, and will remain valid even after the
/// `File` is dropped. In other words, the `MmapMut` handle is completely independent of the `File`
/// used to create it. For consistency, on some platforms this is achieved by duplicating the
/// underlying file handle. The memory will be unmapped when the `MmapMut` handle is dropped.
///
/// Dereferencing and accessing the bytes of the buffer may result in page faults (e.g. swapping
/// the mapped pages into physical memory) though the details of this are platform specific.
///
/// `Mmap` is [`Sync`] and [`Send`].
///
/// See [`Mmap`] for the immutable version.
///
/// ## Safety
///
/// All file-backed memory map constructors are marked `unsafe` because of the potential for
/// *Undefined Behavior* (UB) using the map if the underlying file is subsequently modified, in or
/// out of process. Applications must consider the risk and take appropriate precautions when using
/// file-backed maps. Solutions such as file permissions, locks or process-private (e.g. unlinked)
/// files exist but are platform specific and limited.
pub struct MmapMut {
inner: MmapInner,
}
impl MmapMut {
/// Creates a writeable memory map backed by a file.
///
/// This is equivalent to calling `MmapOptions::new().map_mut(file)`.
///
/// # Errors
///
/// This method returns an error when the underlying system call fails, which can happen for a
/// variety of reasons, such as when the file is not open with read and write permissions.
///
/// # Example
///
/// ```
/// # extern crate memmap2;
/// # extern crate tempfile;
/// #
/// use std::fs::OpenOptions;
/// use std::path::PathBuf;
///
/// use memmap2::MmapMut;
/// #
/// # fn main() -> std::io::Result<()> {
/// # let tempdir = tempfile::tempdir()?;
/// let path: PathBuf = /* path to file */
/// # tempdir.path().join("map_mut");
/// let file = OpenOptions::new()
/// .read(true)
/// .write(true)
/// .create(true)
/// .open(&path)?;
/// file.set_len(13)?;
///
/// let mut mmap = unsafe { MmapMut::map_mut(&file)? };
///
/// mmap.copy_from_slice(b"Hello, world!");
/// # Ok(())
/// # }
/// ```
pub unsafe fn map_mut(file: T) -> Result {
MmapOptions::new().map_mut(file)
}
/// Creates an anonymous memory map.
///
/// This is equivalent to calling `MmapOptions::new().len(length).map_anon()`.
///
/// # Errors
///
/// This method returns an error when the underlying system call fails or
/// when `len > isize::MAX`.
pub fn map_anon(length: usize) -> Result {
MmapOptions::new().len(length).map_anon()
}
/// Flushes outstanding memory map modifications to disk.
///
/// When this method returns with a non-error result, all outstanding changes to a file-backed
/// memory map are guaranteed to be durably stored. The file's metadata (including last
/// modification timestamp) may not be updated.
///
/// # Example
///
/// ```
/// # extern crate memmap2;
/// # extern crate tempfile;
/// #
/// use std::fs::OpenOptions;
/// use std::io::Write;
/// use std::path::PathBuf;
///
/// use memmap2::MmapMut;
///
/// # fn main() -> std::io::Result<()> {
/// # let tempdir = tempfile::tempdir()?;
/// let path: PathBuf = /* path to file */
/// # tempdir.path().join("flush");
/// let file = OpenOptions::new().read(true).write(true).create(true).open(&path)?;
/// file.set_len(128)?;
///
/// let mut mmap = unsafe { MmapMut::map_mut(&file)? };
///
/// (&mut mmap[..]).write_all(b"Hello, world!")?;
/// mmap.flush()?;
/// # Ok(())
/// # }
/// ```
pub fn flush(&self) -> Result<()> {
let len = self.len();
self.inner.flush(0, len)
}
/// Asynchronously flushes outstanding memory map modifications to disk.
///
/// This method initiates flushing modified pages to durable storage, but it will not wait for
/// the operation to complete before returning. The file's metadata (including last
/// modification timestamp) may not be updated.
pub fn flush_async(&self) -> Result<()> {
let len = self.len();
self.inner.flush_async(0, len)
}
/// Flushes outstanding memory map modifications in the range to disk.
///
/// The offset and length must be in the bounds of the memory map.
///
/// When this method returns with a non-error result, all outstanding changes to a file-backed
/// memory in the range are guaranteed to be durable stored. The file's metadata (including
/// last modification timestamp) may not be updated. It is not guaranteed the only the changes
/// in the specified range are flushed; other outstanding changes to the memory map may be
/// flushed as well.
pub fn flush_range(&self, offset: usize, len: usize) -> Result<()> {
self.inner.flush(offset, len)
}
/// Asynchronously flushes outstanding memory map modifications in the range to disk.
///
/// The offset and length must be in the bounds of the memory map.
///
/// This method initiates flushing modified pages to durable storage, but it will not wait for
/// the operation to complete before returning. The file's metadata (including last
/// modification timestamp) may not be updated. It is not guaranteed that the only changes
/// flushed are those in the specified range; other outstanding changes to the memory map may
/// be flushed as well.
pub fn flush_async_range(&self, offset: usize, len: usize) -> Result<()> {
self.inner.flush_async(offset, len)
}
/// Returns an immutable version of this memory mapped buffer.
///
/// If the memory map is file-backed, the file must have been opened with read permissions.
///
/// # Errors
///
/// This method returns an error when the underlying system call fails, which can happen for a
/// variety of reasons, such as when the file has not been opened with read permissions.
///
/// # Example
///
/// ```
/// # extern crate memmap2;
/// #
/// use std::io::Write;
/// use std::path::PathBuf;
///
/// use memmap2::{Mmap, MmapMut};
///
/// # fn main() -> std::io::Result<()> {
/// let mut mmap = MmapMut::map_anon(128)?;
///
/// (&mut mmap[..]).write(b"Hello, world!")?;
///
/// let mmap: Mmap = mmap.make_read_only()?;
/// # Ok(())
/// # }
/// ```
pub fn make_read_only(mut self) -> Result {
self.inner.make_read_only()?;
Ok(Mmap { inner: self.inner })
}
/// Transition the memory map to be readable and executable.
///
/// If the memory map is file-backed, the file must have been opened with execute permissions.
///
/// On systems with separate instructions and data caches (a category that includes many ARM
/// chips), a platform-specific call may be needed to ensure that the changes are visible to the
/// execution unit (e.g. when using this function to implement a JIT compiler). For more
/// details, see [this ARM write-up](https://community.arm.com/arm-community-blogs/b/architectures-and-processors-blog/posts/caches-and-self-modifying-code)
/// or the `man` page for [`sys_icache_invalidate`](https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man3/sys_icache_invalidate.3.html).
///
/// # Errors
///
/// This method returns an error when the underlying system call fails, which can happen for a
/// variety of reasons, such as when the file has not been opened with execute permissions.
pub fn make_exec(mut self) -> Result {
self.inner.make_exec()?;
Ok(Mmap { inner: self.inner })
}
/// Advise OS how this memory map will be accessed.
///
/// Only supported on Unix.
///
/// See [madvise()](https://man7.org/linux/man-pages/man2/madvise.2.html) map page.
#[cfg(unix)]
pub fn advise(&self, advice: Advice) -> Result<()> {
self.inner
.advise(advice as libc::c_int, 0, self.inner.len())
}
/// Advise OS how this memory map will be accessed.
///
/// Used with the [unchecked flags][UncheckedAdvice]. Only supported on Unix.
///
/// See [madvise()](https://man7.org/linux/man-pages/man2/madvise.2.html) map page.
#[cfg(unix)]
pub unsafe fn unchecked_advise(&self, advice: UncheckedAdvice) -> Result<()> {
self.inner
.advise(advice as libc::c_int, 0, self.inner.len())
}
/// Advise OS how this range of memory map will be accessed.
///
/// Only supported on Unix.
///
/// The offset and length must be in the bounds of the memory map.
///
/// See [madvise()](https://man7.org/linux/man-pages/man2/madvise.2.html) map page.
#[cfg(unix)]
pub fn advise_range(&self, advice: Advice, offset: usize, len: usize) -> Result<()> {
self.inner.advise(advice as libc::c_int, offset, len)
}
/// Advise OS how this range of memory map will be accessed.
///
/// Used with the [unchecked flags][UncheckedAdvice]. Only supported on Unix.
///
/// The offset and length must be in the bounds of the memory map.
///
/// See [madvise()](https://man7.org/linux/man-pages/man2/madvise.2.html) map page.
#[cfg(unix)]
pub fn unchecked_advise_range(
&self,
advice: UncheckedAdvice,
offset: usize,
len: usize,
) -> Result<()> {
self.inner.advise(advice as libc::c_int, offset, len)
}
/// Lock the whole memory map into RAM. Only supported on Unix.
///
/// See [mlock()](https://man7.org/linux/man-pages/man2/mlock.2.html) map page.
#[cfg(unix)]
pub fn lock(&self) -> Result<()> {
self.inner.lock()
}
/// Unlock the whole memory map. Only supported on Unix.
///
/// See [munlock()](https://man7.org/linux/man-pages/man2/munlock.2.html) map page.
#[cfg(unix)]
pub fn unlock(&self) -> Result<()> {
self.inner.unlock()
}
/// Adjust the size of the memory mapping.
///
/// This will try to resize the memory mapping in place. If
/// [`RemapOptions::may_move`] is specified it will move the mapping if it
/// could not resize in place, otherwise it will error.
///
/// Only supported on Linux.
///
/// See the [`mremap(2)`] man page.
///
/// # Safety
///
/// Resizing the memory mapping beyond the end of the mapped file will
/// result in UB should you happen to access memory beyond the end of the
/// file.
///
/// [`mremap(2)`]: https://man7.org/linux/man-pages/man2/mremap.2.html
#[cfg(target_os = "linux")]
pub unsafe fn remap(&mut self, new_len: usize, options: RemapOptions) -> Result<()> {
self.inner.remap(new_len, options)
}
}
#[cfg(feature = "stable_deref_trait")]
unsafe impl stable_deref_trait::StableDeref for MmapMut {}
impl Deref for MmapMut {
type Target = [u8];
#[inline]
fn deref(&self) -> &[u8] {
unsafe { slice::from_raw_parts(self.inner.ptr(), self.inner.len()) }
}
}
impl DerefMut for MmapMut {
#[inline]
fn deref_mut(&mut self) -> &mut [u8] {
unsafe { slice::from_raw_parts_mut(self.inner.mut_ptr(), self.inner.len()) }
}
}
impl AsRef<[u8]> for MmapMut {
#[inline]
fn as_ref(&self) -> &[u8] {
self.deref()
}
}
impl AsMut<[u8]> for MmapMut {
#[inline]
fn as_mut(&mut self) -> &mut [u8] {
self.deref_mut()
}
}
impl fmt::Debug for MmapMut {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
fmt.debug_struct("MmapMut")
.field("ptr", &self.as_ptr())
.field("len", &self.len())
.finish()
}
}
/// Options for [`Mmap::remap`] and [`MmapMut::remap`].
#[derive(Copy, Clone, Default, Debug)]
#[cfg(target_os = "linux")]
pub struct RemapOptions {
may_move: bool,
}
#[cfg(target_os = "linux")]
impl RemapOptions {
/// Creates a mew set of options for resizing a memory map.
pub fn new() -> Self {
Self::default()
}
/// Controls whether the memory map can be moved if it is not possible to
/// resize it in place.
///
/// If false then the memory map is guaranteed to remain at the same
/// address when being resized but attempting to resize will return an
/// error if the new memory map would overlap with something else in the
/// current process' memory.
///
/// By default this is false.
///
/// # `may_move` and `StableDeref`
/// If the `stable_deref_trait` feature is enabled then [`Mmap`] and
/// [`MmapMut`] implement `StableDeref`. `StableDeref` promises that the
/// memory map dereferences to a fixed address, however, calling `remap`
/// with `may_move` set may result in the backing memory of the mapping
/// being moved to a new address. This may cause UB in other code
/// depending on the `StableDeref` guarantees.
pub fn may_move(mut self, may_move: bool) -> Self {
self.may_move = may_move;
self
}
pub(crate) fn into_flags(self) -> libc::c_int {
if self.may_move {
libc::MREMAP_MAYMOVE
} else {
0
}
}
}
#[cfg(test)]
mod test {
extern crate tempfile;
#[cfg(unix)]
use crate::advice::Advice;
use std::fs::{File, OpenOptions};
use std::io::{Read, Write};
use std::mem;
#[cfg(unix)]
use std::os::unix::io::AsRawFd;
#[cfg(windows)]
use std::os::windows::fs::OpenOptionsExt;
#[cfg(windows)]
const GENERIC_ALL: u32 = 0x10000000;
use super::{Mmap, MmapMut, MmapOptions};
#[test]
fn map_file() {
let expected_len = 128;
let tempdir = tempfile::tempdir().unwrap();
let path = tempdir.path().join("mmap");
let file = OpenOptions::new()
.read(true)
.write(true)
.create(true)
.open(path)
.unwrap();
file.set_len(expected_len as u64).unwrap();
let mut mmap = unsafe { MmapMut::map_mut(&file).unwrap() };
let len = mmap.len();
assert_eq!(expected_len, len);
let zeros = vec![0; len];
let incr: Vec = (0..len as u8).collect();
// check that the mmap is empty
assert_eq!(&zeros[..], &mmap[..]);
// write values into the mmap
(&mut mmap[..]).write_all(&incr[..]).unwrap();
// read values back
assert_eq!(&incr[..], &mmap[..]);
}
#[test]
#[cfg(unix)]
fn map_fd() {
let expected_len = 128;
let tempdir = tempfile::tempdir().unwrap();
let path = tempdir.path().join("mmap");
let file = OpenOptions::new()
.read(true)
.write(true)
.create(true)
.open(path)
.unwrap();
file.set_len(expected_len as u64).unwrap();
let mut mmap = unsafe { MmapMut::map_mut(file.as_raw_fd()).unwrap() };
let len = mmap.len();
assert_eq!(expected_len, len);
let zeros = vec![0; len];
let incr: Vec = (0..len as u8).collect();
// check that the mmap is empty
assert_eq!(&zeros[..], &mmap[..]);
// write values into the mmap
(&mut mmap[..]).write_all(&incr[..]).unwrap();
// read values back
assert_eq!(&incr[..], &mmap[..]);
}
/// Checks that "mapping" a 0-length file derefs to an empty slice.
#[test]
fn map_empty_file() {
let tempdir = tempfile::tempdir().unwrap();
let path = tempdir.path().join("mmap");
let file = OpenOptions::new()
.read(true)
.write(true)
.create(true)
.open(path)
.unwrap();
let mmap = unsafe { Mmap::map(&file).unwrap() };
assert!(mmap.is_empty());
assert_eq!(mmap.as_ptr().align_offset(mem::size_of::()), 0);
let mmap = unsafe { MmapMut::map_mut(&file).unwrap() };
assert!(mmap.is_empty());
assert_eq!(mmap.as_ptr().align_offset(mem::size_of::()), 0);
}
#[test]
fn map_anon() {
let expected_len = 128;
let mut mmap = MmapMut::map_anon(expected_len).unwrap();
let len = mmap.len();
assert_eq!(expected_len, len);
let zeros = vec![0; len];
let incr: Vec = (0..len as u8).collect();
// check that the mmap is empty
assert_eq!(&zeros[..], &mmap[..]);
// write values into the mmap
(&mut mmap[..]).write_all(&incr[..]).unwrap();
// read values back
assert_eq!(&incr[..], &mmap[..]);
}
#[test]
fn map_anon_zero_len() {
assert!(MmapOptions::new().map_anon().unwrap().is_empty())
}
#[test]
#[cfg(target_pointer_width = "32")]
fn map_anon_len_overflow() {
let res = MmapMut::map_anon(0x80000000);
assert_eq!(
res.unwrap_err().to_string(),
"memory map length overflows isize"
);
}
#[test]
fn file_write() {
let tempdir = tempfile::tempdir().unwrap();
let path = tempdir.path().join("mmap");
let mut file = OpenOptions::new()
.read(true)
.write(true)
.create(true)
.open(path)
.unwrap();
file.set_len(128).unwrap();
let write = b"abc123";
let mut read = [0u8; 6];
let mut mmap = unsafe { MmapMut::map_mut(&file).unwrap() };
(&mut mmap[..]).write_all(write).unwrap();
mmap.flush().unwrap();
file.read_exact(&mut read).unwrap();
assert_eq!(write, &read);
}
#[test]
fn flush_range() {
let tempdir = tempfile::tempdir().unwrap();
let path = tempdir.path().join("mmap");
let file = OpenOptions::new()
.read(true)
.write(true)
.create(true)
.open(path)
.unwrap();
file.set_len(128).unwrap();
let write = b"abc123";
let mut mmap = unsafe {
MmapOptions::new()
.offset(2)
.len(write.len())
.map_mut(&file)
.unwrap()
};
(&mut mmap[..]).write_all(write).unwrap();
mmap.flush_async_range(0, write.len()).unwrap();
mmap.flush_range(0, write.len()).unwrap();
}
#[test]
fn map_copy() {
let tempdir = tempfile::tempdir().unwrap();
let path = tempdir.path().join("mmap");
let mut file = OpenOptions::new()
.read(true)
.write(true)
.create(true)
.open(path)
.unwrap();
file.set_len(128).unwrap();
let nulls = b"\0\0\0\0\0\0";
let write = b"abc123";
let mut read = [0u8; 6];
let mut mmap = unsafe { MmapOptions::new().map_copy(&file).unwrap() };
(&mut mmap[..]).write_all(write).unwrap();
mmap.flush().unwrap();
// The mmap contains the write
(&mmap[..]).read_exact(&mut read).unwrap();
assert_eq!(write, &read);
// The file does not contain the write
file.read_exact(&mut read).unwrap();
assert_eq!(nulls, &read);
// another mmap does not contain the write
let mmap2 = unsafe { MmapOptions::new().map(&file).unwrap() };
(&mmap2[..]).read_exact(&mut read).unwrap();
assert_eq!(nulls, &read);
}
#[test]
fn map_copy_read_only() {
let tempdir = tempfile::tempdir().unwrap();
let path = tempdir.path().join("mmap");
let file = OpenOptions::new()
.read(true)
.write(true)
.create(true)
.open(path)
.unwrap();
file.set_len(128).unwrap();
let nulls = b"\0\0\0\0\0\0";
let mut read = [0u8; 6];
let mmap = unsafe { MmapOptions::new().map_copy_read_only(&file).unwrap() };
(&mmap[..]).read_exact(&mut read).unwrap();
assert_eq!(nulls, &read);
let mmap2 = unsafe { MmapOptions::new().map(&file).unwrap() };
(&mmap2[..]).read_exact(&mut read).unwrap();
assert_eq!(nulls, &read);
}
#[test]
fn map_offset() {
let tempdir = tempfile::tempdir().unwrap();
let path = tempdir.path().join("mmap");
let file = OpenOptions::new()
.read(true)
.write(true)
.create(true)
.open(path)
.unwrap();
let offset = u32::MAX as u64 + 2;
let len = 5432;
file.set_len(offset + len as u64).unwrap();
// Check inferred length mmap.
let mmap = unsafe { MmapOptions::new().offset(offset).map_mut(&file).unwrap() };
assert_eq!(len, mmap.len());
// Check explicit length mmap.
let mut mmap = unsafe {
MmapOptions::new()
.offset(offset)
.len(len)
.map_mut(&file)
.unwrap()
};
assert_eq!(len, mmap.len());
let zeros = vec![0; len];
let incr: Vec<_> = (0..len).map(|i| i as u8).collect();
// check that the mmap is empty
assert_eq!(&zeros[..], &mmap[..]);
// write values into the mmap
(&mut mmap[..]).write_all(&incr[..]).unwrap();
// read values back
assert_eq!(&incr[..], &mmap[..]);
}
#[test]
fn index() {
let mut mmap = MmapMut::map_anon(128).unwrap();
mmap[0] = 42;
assert_eq!(42, mmap[0]);
}
#[test]
fn sync_send() {
let mmap = MmapMut::map_anon(129).unwrap();
fn is_sync_send(_val: T)
where
T: Sync + Send,
{
}
is_sync_send(mmap);
}
#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
fn jit_x86(mut mmap: MmapMut) {
mmap[0] = 0xB8; // mov eax, 0xAB
mmap[1] = 0xAB;
mmap[2] = 0x00;
mmap[3] = 0x00;
mmap[4] = 0x00;
mmap[5] = 0xC3; // ret
let mmap = mmap.make_exec().expect("make_exec");
let jitfn: extern "C" fn() -> u8 = unsafe { mem::transmute(mmap.as_ptr()) };
assert_eq!(jitfn(), 0xab);
}
#[test]
#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
fn jit_x86_anon() {
jit_x86(MmapMut::map_anon(4096).unwrap());
}
#[test]
#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
fn jit_x86_file() {
let tempdir = tempfile::tempdir().unwrap();
let mut options = OpenOptions::new();
#[cfg(windows)]
options.access_mode(GENERIC_ALL);
let file = options
.read(true)
.write(true)
.create(true)
.open(tempdir.path().join("jit_x86"))
.expect("open");
file.set_len(4096).expect("set_len");
jit_x86(unsafe { MmapMut::map_mut(&file).expect("map_mut") });
}
#[test]
fn mprotect_file() {
let tempdir = tempfile::tempdir().unwrap();
let path = tempdir.path().join("mmap");
let mut options = OpenOptions::new();
#[cfg(windows)]
options.access_mode(GENERIC_ALL);
let mut file = options
.read(true)
.write(true)
.create(true)
.open(path)
.expect("open");
file.set_len(256_u64).expect("set_len");
let mmap = unsafe { MmapMut::map_mut(&file).expect("map_mut") };
let mmap = mmap.make_read_only().expect("make_read_only");
let mut mmap = mmap.make_mut().expect("make_mut");
let write = b"abc123";
let mut read = [0u8; 6];
(&mut mmap[..]).write_all(write).unwrap();
mmap.flush().unwrap();
// The mmap contains the write
(&mmap[..]).read_exact(&mut read).unwrap();
assert_eq!(write, &read);
// The file should contain the write
file.read_exact(&mut read).unwrap();
assert_eq!(write, &read);
// another mmap should contain the write
let mmap2 = unsafe { MmapOptions::new().map(&file).unwrap() };
(&mmap2[..]).read_exact(&mut read).unwrap();
assert_eq!(write, &read);
let mmap = mmap.make_exec().expect("make_exec");
drop(mmap);
}
#[test]
fn mprotect_copy() {
let tempdir = tempfile::tempdir().unwrap();
let path = tempdir.path().join("mmap");
let mut options = OpenOptions::new();
#[cfg(windows)]
options.access_mode(GENERIC_ALL);
let mut file = options
.read(true)
.write(true)
.create(true)
.open(path)
.expect("open");
file.set_len(256_u64).expect("set_len");
let mmap = unsafe { MmapOptions::new().map_copy(&file).expect("map_mut") };
let mmap = mmap.make_read_only().expect("make_read_only");
let mut mmap = mmap.make_mut().expect("make_mut");
let nulls = b"\0\0\0\0\0\0";
let write = b"abc123";
let mut read = [0u8; 6];
(&mut mmap[..]).write_all(write).unwrap();
mmap.flush().unwrap();
// The mmap contains the write
(&mmap[..]).read_exact(&mut read).unwrap();
assert_eq!(write, &read);
// The file does not contain the write
file.read_exact(&mut read).unwrap();
assert_eq!(nulls, &read);
// another mmap does not contain the write
let mmap2 = unsafe { MmapOptions::new().map(&file).unwrap() };
(&mmap2[..]).read_exact(&mut read).unwrap();
assert_eq!(nulls, &read);
let mmap = mmap.make_exec().expect("make_exec");
drop(mmap);
}
#[test]
fn mprotect_anon() {
let mmap = MmapMut::map_anon(256).expect("map_mut");
let mmap = mmap.make_read_only().expect("make_read_only");
let mmap = mmap.make_mut().expect("make_mut");
let mmap = mmap.make_exec().expect("make_exec");
drop(mmap);
}
#[test]
fn raw() {
let tempdir = tempfile::tempdir().unwrap();
let path = tempdir.path().join("mmapraw");
let mut options = OpenOptions::new();
let mut file = options
.read(true)
.write(true)
.create(true)
.open(path)
.expect("open");
file.write_all(b"abc123").unwrap();
let mmap = MmapOptions::new().map_raw(&file).unwrap();
assert_eq!(mmap.len(), 6);
assert!(!mmap.as_ptr().is_null());
assert_eq!(unsafe { std::ptr::read(mmap.as_ptr()) }, b'a');
}
#[test]
fn raw_read_only() {
let tempdir = tempfile::tempdir().unwrap();
let path = tempdir.path().join("mmaprawro");
File::create(&path).unwrap().write_all(b"abc123").unwrap();
let mmap = MmapOptions::new()
.map_raw_read_only(&File::open(&path).unwrap())
.unwrap();
assert_eq!(mmap.len(), 6);
assert!(!mmap.as_ptr().is_null());
assert_eq!(unsafe { std::ptr::read(mmap.as_ptr()) }, b'a');
}
/// Something that relies on StableDeref
#[test]
#[cfg(feature = "stable_deref_trait")]
fn owning_ref() {
extern crate owning_ref;
let mut map = MmapMut::map_anon(128).unwrap();
map[10] = 42;
let owning = owning_ref::OwningRef::new(map);
let sliced = owning.map(|map| &map[10..20]);
assert_eq!(42, sliced[0]);
let map = sliced.into_owner().make_read_only().unwrap();
let owning = owning_ref::OwningRef::new(map);
let sliced = owning.map(|map| &map[10..20]);
assert_eq!(42, sliced[0]);
}
#[test]
#[cfg(unix)]
fn advise() {
let expected_len = 128;
let tempdir = tempfile::tempdir().unwrap();
let path = tempdir.path().join("mmap_advise");
let file = OpenOptions::new()
.read(true)
.write(true)
.create(true)
.open(path)
.unwrap();
file.set_len(expected_len as u64).unwrap();
// Test MmapMut::advise
let mut mmap = unsafe { MmapMut::map_mut(&file).unwrap() };
mmap.advise(Advice::Random)
.expect("mmap advising should be supported on unix");
let len = mmap.len();
assert_eq!(expected_len, len);
let zeros = vec![0; len];
let incr: Vec = (0..len as u8).collect();
// check that the mmap is empty
assert_eq!(&zeros[..], &mmap[..]);
mmap.advise_range(Advice::Sequential, 0, mmap.len())
.expect("mmap advising should be supported on unix");
// write values into the mmap
(&mut mmap[..]).write_all(&incr[..]).unwrap();
// read values back
assert_eq!(&incr[..], &mmap[..]);
// Set advice and Read from the read-only map
let mmap = unsafe { Mmap::map(&file).unwrap() };
mmap.advise(Advice::Random)
.expect("mmap advising should be supported on unix");
// read values back
assert_eq!(&incr[..], &mmap[..]);
}
#[test]
#[cfg(target_os = "linux")]
fn advise_writes_unsafely() {
let page_size = unsafe { libc::sysconf(libc::_SC_PAGESIZE) as usize };
let mut mmap = MmapMut::map_anon(page_size).unwrap();
mmap.as_mut().fill(255);
let mmap = mmap.make_read_only().unwrap();
let a = mmap.as_ref()[0];
unsafe {
mmap.unchecked_advise(crate::UncheckedAdvice::DontNeed)
.unwrap();
}
let b = mmap.as_ref()[0];
assert_eq!(a, 255);
assert_eq!(b, 0);
}
#[test]
#[cfg(target_os = "linux")]
fn advise_writes_unsafely_to_part_of_map() {
let page_size = unsafe { libc::sysconf(libc::_SC_PAGESIZE) as usize };
let mut mmap = MmapMut::map_anon(2 * page_size).unwrap();
mmap.as_mut().fill(255);
let mmap = mmap.make_read_only().unwrap();
let a = mmap.as_ref()[0];
let b = mmap.as_ref()[page_size];
unsafe {
mmap.unchecked_advise_range(crate::UncheckedAdvice::DontNeed, page_size, page_size)
.unwrap();
}
let c = mmap.as_ref()[0];
let d = mmap.as_ref()[page_size];
assert_eq!(a, 255);
assert_eq!(b, 255);
assert_eq!(c, 255);
assert_eq!(d, 0);
}
/// Returns true if a non-zero amount of memory is locked.
#[cfg(target_os = "linux")]
fn is_locked() -> bool {
let status = &std::fs::read_to_string("/proc/self/status")
.expect("/proc/self/status should be available");
for line in status.lines() {
if line.starts_with("VmLck:") {
let numbers = line.replace(|c: char| !c.is_ascii_digit(), "");
return numbers != "0";
}
}
panic!("cannot get VmLck information")
}
#[test]
#[cfg(unix)]
fn lock() {
let tempdir = tempfile::tempdir().unwrap();
let path = tempdir.path().join("mmap_lock");
let file = OpenOptions::new()
.read(true)
.write(true)
.create(true)
.open(path)
.unwrap();
file.set_len(128).unwrap();
let mmap = unsafe { Mmap::map(&file).unwrap() };
#[cfg(target_os = "linux")]
assert!(!is_locked());
mmap.lock().expect("mmap lock should be supported on unix");
#[cfg(target_os = "linux")]
assert!(is_locked());
mmap.lock()
.expect("mmap lock again should not cause problems");
#[cfg(target_os = "linux")]
assert!(is_locked());
mmap.unlock()
.expect("mmap unlock should be supported on unix");
#[cfg(target_os = "linux")]
assert!(!is_locked());
mmap.unlock()
.expect("mmap unlock again should not cause problems");
#[cfg(target_os = "linux")]
assert!(!is_locked());
}
#[test]
#[cfg(target_os = "linux")]
fn remap_grow() {
use crate::RemapOptions;
let initial_len = 128;
let final_len = 2000;
let zeros = vec![0u8; final_len];
let incr: Vec = (0..final_len).map(|v| v as u8).collect();
let file = tempfile::tempfile().unwrap();
file.set_len(final_len as u64).unwrap();
let mut mmap = unsafe { MmapOptions::new().len(initial_len).map_mut(&file).unwrap() };
assert_eq!(mmap.len(), initial_len);
assert_eq!(&mmap[..], &zeros[..initial_len]);
unsafe {
mmap.remap(final_len, RemapOptions::new().may_move(true))
.unwrap()
};
// The size should have been updated
assert_eq!(mmap.len(), final_len);
// Should still be all zeros
assert_eq!(&mmap[..], &zeros);
// Write out to the whole expanded slice.
mmap.copy_from_slice(&incr);
}
#[test]
#[cfg(target_os = "linux")]
fn remap_shrink() {
use crate::RemapOptions;
let initial_len = 20000;
let final_len = 400;
let incr: Vec = (0..final_len).map(|v| v as u8).collect();
let file = tempfile::tempfile().unwrap();
file.set_len(initial_len as u64).unwrap();
let mut mmap = unsafe { MmapMut::map_mut(&file).unwrap() };
assert_eq!(mmap.len(), initial_len);
unsafe { mmap.remap(final_len, RemapOptions::new()).unwrap() };
assert_eq!(mmap.len(), final_len);
// Check that the mmap is still writable along the slice length
mmap.copy_from_slice(&incr);
}
#[test]
#[cfg(target_os = "linux")]
#[cfg(target_pointer_width = "32")]
fn remap_len_overflow() {
use crate::RemapOptions;
let file = tempfile::tempfile().unwrap();
file.set_len(1024).unwrap();
let mut mmap = unsafe { MmapOptions::new().len(1024).map(&file).unwrap() };
let res = unsafe { mmap.remap(0x80000000, RemapOptions::new().may_move(true)) };
assert_eq!(
res.unwrap_err().to_string(),
"memory map length overflows isize"
);
assert_eq!(mmap.len(), 1024);
}
#[test]
#[cfg(target_os = "linux")]
fn remap_with_offset() {
use crate::RemapOptions;
let offset = 77;
let initial_len = 128;
let final_len = 2000;
let zeros = vec![0u8; final_len];
let incr: Vec = (0..final_len).map(|v| v as u8).collect();
let file = tempfile::tempfile().unwrap();
file.set_len(final_len as u64 + offset).unwrap();
let mut mmap = unsafe {
MmapOptions::new()
.len(initial_len)
.offset(offset)
.map_mut(&file)
.unwrap()
};
assert_eq!(mmap.len(), initial_len);
assert_eq!(&mmap[..], &zeros[..initial_len]);
unsafe {
mmap.remap(final_len, RemapOptions::new().may_move(true))
.unwrap()
};
// The size should have been updated
assert_eq!(mmap.len(), final_len);
// Should still be all zeros
assert_eq!(&mmap[..], &zeros);
// Write out to the whole expanded slice.
mmap.copy_from_slice(&incr);
}
}
memmap2-0.9.3/src/stub.rs 0000644 0000000 0000000 00000003520 10461020230 0013305 0 ustar 0000000 0000000 use std::fs::File;
use std::io;
// A stable alternative to https://doc.rust-lang.org/stable/std/primitive.never.html
enum Never {}
pub struct MmapInner {
never: Never,
}
impl MmapInner {
fn new() -> io::Result {
Err(io::Error::new(
io::ErrorKind::Other,
"platform not supported",
))
}
pub fn map(_: usize, _: &File, _: u64, _: bool) -> io::Result {
MmapInner::new()
}
pub fn map_exec(_: usize, _: &File, _: u64, _: bool) -> io::Result {
MmapInner::new()
}
pub fn map_mut(_: usize, _: &File, _: u64, _: bool) -> io::Result {
MmapInner::new()
}
pub fn map_copy(_: usize, _: &File, _: u64, _: bool) -> io::Result {
MmapInner::new()
}
pub fn map_copy_read_only(_: usize, _: &File, _: u64, _: bool) -> io::Result {
MmapInner::new()
}
pub fn map_anon(_: usize, _: bool, _: bool, _: Option) -> io::Result {
MmapInner::new()
}
pub fn flush(&self, _: usize, _: usize) -> io::Result<()> {
match self.never {}
}
pub fn flush_async(&self, _: usize, _: usize) -> io::Result<()> {
match self.never {}
}
pub fn make_read_only(&mut self) -> io::Result<()> {
match self.never {}
}
pub fn make_exec(&mut self) -> io::Result<()> {
match self.never {}
}
pub fn make_mut(&mut self) -> io::Result<()> {
match self.never {}
}
#[inline]
pub fn ptr(&self) -> *const u8 {
match self.never {}
}
#[inline]
pub fn mut_ptr(&mut self) -> *mut u8 {
match self.never {}
}
#[inline]
pub fn len(&self) -> usize {
match self.never {}
}
}
pub fn file_len(file: &File) -> io::Result {
Ok(file.metadata()?.len())
}
memmap2-0.9.3/src/unix.rs 0000644 0000000 0000000 00000036660 10461020230 0013326 0 ustar 0000000 0000000 extern crate libc;
use std::fs::File;
use std::mem::ManuallyDrop;
use std::os::unix::io::{FromRawFd, RawFd};
use std::sync::atomic::{AtomicUsize, Ordering};
use std::{io, ptr};
#[cfg(any(
all(target_os = "linux", not(target_arch = "mips")),
target_os = "freebsd",
target_os = "android"
))]
const MAP_STACK: libc::c_int = libc::MAP_STACK;
#[cfg(not(any(
all(target_os = "linux", not(target_arch = "mips")),
target_os = "freebsd",
target_os = "android"
)))]
const MAP_STACK: libc::c_int = 0;
#[cfg(any(target_os = "linux", target_os = "android"))]
const MAP_POPULATE: libc::c_int = libc::MAP_POPULATE;
#[cfg(not(any(target_os = "linux", target_os = "android")))]
const MAP_POPULATE: libc::c_int = 0;
#[cfg(any(target_os = "linux", target_os = "android"))]
const MAP_HUGETLB: libc::c_int = libc::MAP_HUGETLB;
#[cfg(target_os = "linux")]
const MAP_HUGE_MASK: libc::c_int = libc::MAP_HUGE_MASK;
#[cfg(any(target_os = "linux", target_os = "android"))]
const MAP_HUGE_SHIFT: libc::c_int = libc::MAP_HUGE_SHIFT;
#[cfg(not(any(target_os = "linux", target_os = "android")))]
const MAP_HUGETLB: libc::c_int = 0;
#[cfg(not(target_os = "linux"))]
const MAP_HUGE_MASK: libc::c_int = 0;
#[cfg(not(any(target_os = "linux", target_os = "android")))]
const MAP_HUGE_SHIFT: libc::c_int = 0;
#[cfg(any(
target_os = "android",
all(target_os = "linux", not(target_env = "musl"))
))]
use libc::{mmap64 as mmap, off64_t as off_t};
#[cfg(not(any(
target_os = "android",
all(target_os = "linux", not(target_env = "musl"))
)))]
use libc::{mmap, off_t};
pub struct MmapInner {
ptr: *mut libc::c_void,
len: usize,
}
impl MmapInner {
/// Creates a new `MmapInner`.
///
/// This is a thin wrapper around the `mmap` system call.
fn new(
len: usize,
prot: libc::c_int,
flags: libc::c_int,
file: RawFd,
offset: u64,
) -> io::Result {
let alignment = offset % page_size() as u64;
let aligned_offset = offset - alignment;
let (map_len, map_offset) = Self::adjust_mmap_params(len, alignment as usize)?;
unsafe {
let ptr = mmap(
ptr::null_mut(),
map_len as libc::size_t,
prot,
flags,
file,
aligned_offset as off_t,
);
if ptr == libc::MAP_FAILED {
Err(io::Error::last_os_error())
} else {
Ok(Self::from_raw_parts(ptr, len, map_offset))
}
}
}
fn adjust_mmap_params(len: usize, alignment: usize) -> io::Result<(usize, usize)> {
use std::isize;
// Rust's slice cannot be larger than isize::MAX.
// See https://doc.rust-lang.org/std/slice/fn.from_raw_parts.html
//
// This is not a problem on 64-bit targets, but on 32-bit one
// having a file or an anonymous mapping larger than 2GB is quite normal
// and we have to prevent it.
//
// The code below is essentially the same as in Rust's std:
// https://github.com/rust-lang/rust/blob/db78ab70a88a0a5e89031d7ee4eccec835dcdbde/library/alloc/src/raw_vec.rs#L495
if std::mem::size_of::() < 8 && len > isize::MAX as usize {
return Err(io::Error::new(
io::ErrorKind::InvalidData,
"memory map length overflows isize",
));
}
let map_len = len + alignment;
let map_offset = alignment;
// `libc::mmap` does not support zero-size mappings. POSIX defines:
//
// https://pubs.opengroup.org/onlinepubs/9699919799/functions/mmap.html
// > If `len` is zero, `mmap()` shall fail and no mapping shall be established.
//
// So if we would create such a mapping, crate a one-byte mapping instead:
let map_len = map_len.max(1);
// Note that in that case `MmapInner::len` is still set to zero,
// and `Mmap` will still dereferences to an empty slice.
//
// If this mapping is backed by an empty file, we create a mapping larger than the file.
// This is unusual but well-defined. On the same man page, POSIX further defines:
//
// > The `mmap()` function can be used to map a region of memory that is larger
// > than the current size of the object.
//
// (The object here is the file.)
//
// > Memory access within the mapping but beyond the current end of the underlying
// > objects may result in SIGBUS signals being sent to the process. The reason for this
// > is that the size of the object can be manipulated by other processes and can change
// > at any moment. The implementation should tell the application that a memory reference
// > is outside the object where this can be detected; otherwise, written data may be lost
// > and read data may not reflect actual data in the object.
//
// Because `MmapInner::len` is not incremented, this increment of `aligned_len`
// will not allow accesses past the end of the file and will not cause SIGBUS.
//
// (SIGBUS is still possible by mapping a non-empty file and then truncating it
// to a shorter size, but that is unrelated to this handling of empty files.)
Ok((map_len, map_offset))
}
/// Get the current memory mapping as a `(ptr, map_len, offset)` tuple.
///
/// Note that `map_len` is the length of the memory mapping itself and
/// _not_ the one that would be passed to `from_raw_parts`.
fn as_mmap_params(&self) -> (*mut libc::c_void, usize, usize) {
let offset = self.ptr as usize % page_size();
let len = self.len + offset;
// There are two possible memory layouts we could have, depending on
// the length and offset passed when constructing this instance:
//
// 1. The "normal" memory layout looks like this:
//
// |<------------------>|<---------------------->|
// mmap ptr offset ptr public slice
//
// That is, we have
// - The start of the page-aligned memory mapping returned by mmap,
// followed by,
// - Some number of bytes that are memory mapped but ignored since
// they are before the byte offset requested by the user, followed
// by,
// - The actual memory mapped slice requested by the user.
//
// This maps cleanly to a (ptr, len, offset) tuple.
//
// 2. Then, we have the case where the user requested a zero-length
// memory mapping. mmap(2) does not support zero-length mappings so
// this crate works around that by actually making a mapping of
// length one. This means that we have
// - A length zero slice, followed by,
// - A single memory mapped byte
//
// Note that this only happens if the offset within the page is also
// zero. Otherwise, we have a memory map of offset bytes and not a
// zero-length memory map.
//
// This doesn't fit cleanly into a (ptr, len, offset) tuple. Instead,
// we fudge it slightly: a zero-length memory map turns into a
// mapping of length one and can't be told apart outside of this
// method without knowing the original length.
if len == 0 {
(self.ptr, 1, 0)
} else {
(unsafe { self.ptr.offset(-(offset as isize)) }, len, offset)
}
}
/// Construct this `MmapInner` from its raw components
///
/// # Safety
///
/// - `ptr` must point to the start of memory mapping that can be freed
/// using `munmap(2)` (i.e. returned by `mmap(2)` or `mremap(2)`)
/// - The memory mapping at `ptr` must have a length of `len + offset`.
/// - If `len + offset == 0` then the memory mapping must be of length 1.
/// - `offset` must be less than the current page size.
unsafe fn from_raw_parts(ptr: *mut libc::c_void, len: usize, offset: usize) -> Self {
debug_assert_eq!(ptr as usize % page_size(), 0, "ptr not page-aligned");
debug_assert!(offset < page_size(), "offset larger than page size");
Self {
ptr: ptr.add(offset),
len,
}
}
pub fn map(len: usize, file: RawFd, offset: u64, populate: bool) -> io::Result {
let populate = if populate { MAP_POPULATE } else { 0 };
MmapInner::new(
len,
libc::PROT_READ,
libc::MAP_SHARED | populate,
file,
offset,
)
}
pub fn map_exec(len: usize, file: RawFd, offset: u64, populate: bool) -> io::Result {
let populate = if populate { MAP_POPULATE } else { 0 };
MmapInner::new(
len,
libc::PROT_READ | libc::PROT_EXEC,
libc::MAP_SHARED | populate,
file,
offset,
)
}
pub fn map_mut(len: usize, file: RawFd, offset: u64, populate: bool) -> io::Result {
let populate = if populate { MAP_POPULATE } else { 0 };
MmapInner::new(
len,
libc::PROT_READ | libc::PROT_WRITE,
libc::MAP_SHARED | populate,
file,
offset,
)
}
pub fn map_copy(len: usize, file: RawFd, offset: u64, populate: bool) -> io::Result {
let populate = if populate { MAP_POPULATE } else { 0 };
MmapInner::new(
len,
libc::PROT_READ | libc::PROT_WRITE,
libc::MAP_PRIVATE | populate,
file,
offset,
)
}
pub fn map_copy_read_only(
len: usize,
file: RawFd,
offset: u64,
populate: bool,
) -> io::Result {
let populate = if populate { MAP_POPULATE } else { 0 };
MmapInner::new(
len,
libc::PROT_READ,
libc::MAP_PRIVATE | populate,
file,
offset,
)
}
/// Open an anonymous memory map.
pub fn map_anon(
len: usize,
stack: bool,
populate: bool,
huge: Option,
) -> io::Result {
let stack = if stack { MAP_STACK } else { 0 };
let populate = if populate { MAP_POPULATE } else { 0 };
let hugetlb = if huge.is_some() { MAP_HUGETLB } else { 0 };
let offset = huge
.map(|mask| ((mask as u64) & (MAP_HUGE_MASK as u64)) << MAP_HUGE_SHIFT)
.unwrap_or(0);
MmapInner::new(
len,
libc::PROT_READ | libc::PROT_WRITE,
libc::MAP_PRIVATE | libc::MAP_ANON | stack | populate | hugetlb,
-1,
offset,
)
}
pub fn flush(&self, offset: usize, len: usize) -> io::Result<()> {
let alignment = (self.ptr as usize + offset) % page_size();
let offset = offset as isize - alignment as isize;
let len = len + alignment;
let result =
unsafe { libc::msync(self.ptr.offset(offset), len as libc::size_t, libc::MS_SYNC) };
if result == 0 {
Ok(())
} else {
Err(io::Error::last_os_error())
}
}
pub fn flush_async(&self, offset: usize, len: usize) -> io::Result<()> {
let alignment = (self.ptr as usize + offset) % page_size();
let offset = offset as isize - alignment as isize;
let len = len + alignment;
let result =
unsafe { libc::msync(self.ptr.offset(offset), len as libc::size_t, libc::MS_ASYNC) };
if result == 0 {
Ok(())
} else {
Err(io::Error::last_os_error())
}
}
fn mprotect(&mut self, prot: libc::c_int) -> io::Result<()> {
unsafe {
let alignment = self.ptr as usize % page_size();
let ptr = self.ptr.offset(-(alignment as isize));
let len = self.len + alignment;
let len = len.max(1);
if libc::mprotect(ptr, len, prot) == 0 {
Ok(())
} else {
Err(io::Error::last_os_error())
}
}
}
pub fn make_read_only(&mut self) -> io::Result<()> {
self.mprotect(libc::PROT_READ)
}
pub fn make_exec(&mut self) -> io::Result<()> {
self.mprotect(libc::PROT_READ | libc::PROT_EXEC)
}
pub fn make_mut(&mut self) -> io::Result<()> {
self.mprotect(libc::PROT_READ | libc::PROT_WRITE)
}
#[inline]
pub fn ptr(&self) -> *const u8 {
self.ptr as *const u8
}
#[inline]
pub fn mut_ptr(&mut self) -> *mut u8 {
self.ptr as *mut u8
}
#[inline]
pub fn len(&self) -> usize {
self.len
}
pub fn advise(&self, advice: libc::c_int, offset: usize, len: usize) -> io::Result<()> {
let alignment = (self.ptr as usize + offset) % page_size();
let offset = offset as isize - alignment as isize;
let len = len + alignment;
unsafe {
if libc::madvise(self.ptr.offset(offset), len, advice) != 0 {
Err(io::Error::last_os_error())
} else {
Ok(())
}
}
}
#[cfg(target_os = "linux")]
pub fn remap(&mut self, new_len: usize, options: crate::RemapOptions) -> io::Result<()> {
let (old_ptr, old_len, offset) = self.as_mmap_params();
let (map_len, offset) = Self::adjust_mmap_params(new_len, offset)?;
unsafe {
let new_ptr = libc::mremap(old_ptr, old_len, map_len, options.into_flags());
if new_ptr == libc::MAP_FAILED {
Err(io::Error::last_os_error())
} else {
// We explicitly don't drop self since the pointer within is no longer valid.
ptr::write(self, Self::from_raw_parts(new_ptr, new_len, offset));
Ok(())
}
}
}
pub fn lock(&self) -> io::Result<()> {
unsafe {
if libc::mlock(self.ptr, self.len) != 0 {
Err(io::Error::last_os_error())
} else {
Ok(())
}
}
}
pub fn unlock(&self) -> io::Result<()> {
unsafe {
if libc::munlock(self.ptr, self.len) != 0 {
Err(io::Error::last_os_error())
} else {
Ok(())
}
}
}
}
impl Drop for MmapInner {
fn drop(&mut self) {
let (ptr, len, _) = self.as_mmap_params();
// Any errors during unmapping/closing are ignored as the only way
// to report them would be through panicking which is highly discouraged
// in Drop impls, c.f. https://github.com/rust-lang/lang-team/issues/97
unsafe { libc::munmap(ptr, len as libc::size_t) };
}
}
unsafe impl Sync for MmapInner {}
unsafe impl Send for MmapInner {}
fn page_size() -> usize {
static PAGE_SIZE: AtomicUsize = AtomicUsize::new(0);
match PAGE_SIZE.load(Ordering::Relaxed) {
0 => {
let page_size = unsafe { libc::sysconf(libc::_SC_PAGESIZE) as usize };
PAGE_SIZE.store(page_size, Ordering::Relaxed);
page_size
}
page_size => page_size,
}
}
pub fn file_len(file: RawFd) -> io::Result {
// SAFETY: We must not close the passed-in fd by dropping the File we create,
// we ensure this by immediately wrapping it in a ManuallyDrop.
unsafe {
let file = ManuallyDrop::new(File::from_raw_fd(file));
Ok(file.metadata()?.len())
}
}
memmap2-0.9.3/src/windows.rs 0000644 0000000 0000000 00000036034 10461020230 0014030 0 ustar 0000000 0000000 #![allow(non_camel_case_types)]
#![allow(non_snake_case)]
use std::fs::File;
use std::mem::ManuallyDrop;
use std::os::raw::c_void;
use std::os::windows::io::{FromRawHandle, RawHandle};
use std::{io, mem, ptr};
type BOOL = i32;
type WORD = u16;
type DWORD = u32;
type WCHAR = u16;
type HANDLE = *mut c_void;
type LPHANDLE = *mut HANDLE;
type LPVOID = *mut c_void;
type LPCVOID = *const c_void;
type ULONG_PTR = usize;
type SIZE_T = ULONG_PTR;
type LPCWSTR = *const WCHAR;
type PDWORD = *mut DWORD;
type DWORD_PTR = ULONG_PTR;
type LPSECURITY_ATTRIBUTES = *mut SECURITY_ATTRIBUTES;
type LPSYSTEM_INFO = *mut SYSTEM_INFO;
const INVALID_HANDLE_VALUE: HANDLE = -1isize as HANDLE;
const DUPLICATE_SAME_ACCESS: DWORD = 0x00000002;
const STANDARD_RIGHTS_REQUIRED: DWORD = 0x000F0000;
const SECTION_QUERY: DWORD = 0x0001;
const SECTION_MAP_WRITE: DWORD = 0x0002;
const SECTION_MAP_READ: DWORD = 0x0004;
const SECTION_MAP_EXECUTE: DWORD = 0x0008;
const SECTION_EXTEND_SIZE: DWORD = 0x0010;
const SECTION_MAP_EXECUTE_EXPLICIT: DWORD = 0x0020;
const SECTION_ALL_ACCESS: DWORD = STANDARD_RIGHTS_REQUIRED
| SECTION_QUERY
| SECTION_MAP_WRITE
| SECTION_MAP_READ
| SECTION_MAP_EXECUTE
| SECTION_EXTEND_SIZE;
const PAGE_READONLY: DWORD = 0x02;
const PAGE_READWRITE: DWORD = 0x04;
const PAGE_WRITECOPY: DWORD = 0x08;
const PAGE_EXECUTE_READ: DWORD = 0x20;
const PAGE_EXECUTE_READWRITE: DWORD = 0x40;
const PAGE_EXECUTE_WRITECOPY: DWORD = 0x80;
const FILE_MAP_WRITE: DWORD = SECTION_MAP_WRITE;
const FILE_MAP_READ: DWORD = SECTION_MAP_READ;
const FILE_MAP_ALL_ACCESS: DWORD = SECTION_ALL_ACCESS;
const FILE_MAP_EXECUTE: DWORD = SECTION_MAP_EXECUTE_EXPLICIT;
const FILE_MAP_COPY: DWORD = 0x00000001;
#[repr(C)]
struct SECURITY_ATTRIBUTES {
nLength: DWORD,
lpSecurityDescriptor: LPVOID,
bInheritHandle: BOOL,
}
#[repr(C)]
struct SYSTEM_INFO {
wProcessorArchitecture: WORD,
wReserved: WORD,
dwPageSize: DWORD,
lpMinimumApplicationAddress: LPVOID,
lpMaximumApplicationAddress: LPVOID,
dwActiveProcessorMask: DWORD_PTR,
dwNumberOfProcessors: DWORD,
dwProcessorType: DWORD,
dwAllocationGranularity: DWORD,
wProcessorLevel: WORD,
wProcessorRevision: WORD,
}
#[repr(C)]
#[derive(Copy, Clone)]
pub struct FILETIME {
pub dwLowDateTime: DWORD,
pub dwHighDateTime: DWORD,
}
extern "system" {
fn GetCurrentProcess() -> HANDLE;
fn CloseHandle(hObject: HANDLE) -> BOOL;
fn DuplicateHandle(
hSourceProcessHandle: HANDLE,
hSourceHandle: HANDLE,
hTargetProcessHandle: HANDLE,
lpTargetHandle: LPHANDLE,
dwDesiredAccess: DWORD,
bInheritHandle: BOOL,
dwOptions: DWORD,
) -> BOOL;
fn CreateFileMappingW(
hFile: HANDLE,
lpFileMappingAttributes: LPSECURITY_ATTRIBUTES,
flProtect: DWORD,
dwMaximumSizeHigh: DWORD,
dwMaximumSizeLow: DWORD,
lpName: LPCWSTR,
) -> HANDLE;
fn FlushFileBuffers(hFile: HANDLE) -> BOOL;
fn FlushViewOfFile(lpBaseAddress: LPCVOID, dwNumberOfBytesToFlush: SIZE_T) -> BOOL;
fn UnmapViewOfFile(lpBaseAddress: LPCVOID) -> BOOL;
fn MapViewOfFile(
hFileMappingObject: HANDLE,
dwDesiredAccess: DWORD,
dwFileOffsetHigh: DWORD,
dwFileOffsetLow: DWORD,
dwNumberOfBytesToMap: SIZE_T,
) -> LPVOID;
fn VirtualProtect(
lpAddress: LPVOID,
dwSize: SIZE_T,
flNewProtect: DWORD,
lpflOldProtect: PDWORD,
) -> BOOL;
fn GetSystemInfo(lpSystemInfo: LPSYSTEM_INFO);
}
/// Returns a fixed aligned pointer that is valid for `slice::from_raw_parts::` with `len == 0`.
///
/// This aligns the pointer to `allocation_granularity()` or 1 if unknown.
fn empty_slice_ptr() -> *mut c_void {
let align = allocation_granularity().max(1);
unsafe { mem::transmute(align) }
}
pub struct MmapInner {
handle: Option,
ptr: *mut c_void,
len: usize,
copy: bool,
}
impl MmapInner {
/// Creates a new `MmapInner`.
///
/// This is a thin wrapper around the `CreateFileMappingW` and `MapViewOfFile` system calls.
pub fn new(
handle: RawHandle,
protect: DWORD,
access: DWORD,
offset: u64,
len: usize,
copy: bool,
) -> io::Result {
let alignment = offset % allocation_granularity() as u64;
let aligned_offset = offset - alignment as u64;
let aligned_len = len + alignment as usize;
if aligned_len == 0 {
// `CreateFileMappingW` documents:
//
// https://docs.microsoft.com/en-us/windows/win32/api/memoryapi/nf-memoryapi-createfilemappingw
// > An attempt to map a file with a length of 0 (zero) fails with an error code
// > of ERROR_FILE_INVALID. Applications should test for files with a length of 0
// > (zero) and reject those files.
//
// For such files, don’t create a mapping at all and use a marker pointer instead.
return Ok(MmapInner {
handle: None,
ptr: empty_slice_ptr(),
len: 0,
copy,
});
}
unsafe {
let mapping = CreateFileMappingW(handle, ptr::null_mut(), protect, 0, 0, ptr::null());
if mapping.is_null() {
return Err(io::Error::last_os_error());
}
let ptr = MapViewOfFile(
mapping,
access,
(aligned_offset >> 16 >> 16) as DWORD,
(aligned_offset & 0xffffffff) as DWORD,
aligned_len as SIZE_T,
);
CloseHandle(mapping);
if ptr.is_null() {
return Err(io::Error::last_os_error());
}
let mut new_handle = 0 as RawHandle;
let cur_proc = GetCurrentProcess();
let ok = DuplicateHandle(
cur_proc,
handle,
cur_proc,
&mut new_handle,
0,
0,
DUPLICATE_SAME_ACCESS,
);
if ok == 0 {
UnmapViewOfFile(ptr);
return Err(io::Error::last_os_error());
}
Ok(MmapInner {
handle: Some(new_handle),
ptr: ptr.offset(alignment as isize),
len: len as usize,
copy,
})
}
}
pub fn map(
len: usize,
handle: RawHandle,
offset: u64,
_populate: bool,
) -> io::Result {
let write = protection_supported(handle, PAGE_READWRITE);
let exec = protection_supported(handle, PAGE_EXECUTE_READ);
let mut access = FILE_MAP_READ;
let protection = match (write, exec) {
(true, true) => {
access |= FILE_MAP_WRITE | FILE_MAP_EXECUTE;
PAGE_EXECUTE_READWRITE
}
(true, false) => {
access |= FILE_MAP_WRITE;
PAGE_READWRITE
}
(false, true) => {
access |= FILE_MAP_EXECUTE;
PAGE_EXECUTE_READ
}
(false, false) => PAGE_READONLY,
};
let mut inner = MmapInner::new(handle, protection, access, offset, len, false)?;
if write || exec {
inner.make_read_only()?;
}
Ok(inner)
}
pub fn map_exec(
len: usize,
handle: RawHandle,
offset: u64,
_populate: bool,
) -> io::Result {
let write = protection_supported(handle, PAGE_READWRITE);
let mut access = FILE_MAP_READ | FILE_MAP_EXECUTE;
let protection = if write {
access |= FILE_MAP_WRITE;
PAGE_EXECUTE_READWRITE
} else {
PAGE_EXECUTE_READ
};
let mut inner = MmapInner::new(handle, protection, access, offset, len, false)?;
if write {
inner.make_exec()?;
}
Ok(inner)
}
pub fn map_mut(
len: usize,
handle: RawHandle,
offset: u64,
_populate: bool,
) -> io::Result {
let exec = protection_supported(handle, PAGE_EXECUTE_READ);
let mut access = FILE_MAP_READ | FILE_MAP_WRITE;
let protection = if exec {
access |= FILE_MAP_EXECUTE;
PAGE_EXECUTE_READWRITE
} else {
PAGE_READWRITE
};
let mut inner = MmapInner::new(handle, protection, access, offset, len, false)?;
if exec {
inner.make_mut()?;
}
Ok(inner)
}
pub fn map_copy(
len: usize,
handle: RawHandle,
offset: u64,
_populate: bool,
) -> io::Result {
let exec = protection_supported(handle, PAGE_EXECUTE_READWRITE);
let mut access = FILE_MAP_COPY;
let protection = if exec {
access |= FILE_MAP_EXECUTE;
PAGE_EXECUTE_WRITECOPY
} else {
PAGE_WRITECOPY
};
let mut inner = MmapInner::new(handle, protection, access, offset, len, true)?;
if exec {
inner.make_mut()?;
}
Ok(inner)
}
pub fn map_copy_read_only(
len: usize,
handle: RawHandle,
offset: u64,
_populate: bool,
) -> io::Result {
let write = protection_supported(handle, PAGE_READWRITE);
let exec = protection_supported(handle, PAGE_EXECUTE_READ);
let mut access = FILE_MAP_COPY;
let protection = if exec {
access |= FILE_MAP_EXECUTE;
PAGE_EXECUTE_WRITECOPY
} else {
PAGE_WRITECOPY
};
let mut inner = MmapInner::new(handle, protection, access, offset, len, true)?;
if write || exec {
inner.make_read_only()?;
}
Ok(inner)
}
pub fn map_anon(
len: usize,
_stack: bool,
_populate: bool,
_huge: Option,
) -> io::Result {
// Ensure a non-zero length for the underlying mapping
let mapped_len = len.max(1);
unsafe {
// Create a mapping and view with maximum access permissions, then use `VirtualProtect`
// to set the actual `Protection`. This way, we can set more permissive protection later
// on.
// Also see https://msdn.microsoft.com/en-us/library/windows/desktop/aa366537.aspx
let mapping = CreateFileMappingW(
INVALID_HANDLE_VALUE,
ptr::null_mut(),
PAGE_EXECUTE_READWRITE,
(mapped_len >> 16 >> 16) as DWORD,
(mapped_len & 0xffffffff) as DWORD,
ptr::null(),
);
if mapping.is_null() {
return Err(io::Error::last_os_error());
}
let access = FILE_MAP_ALL_ACCESS | FILE_MAP_EXECUTE;
let ptr = MapViewOfFile(mapping, access, 0, 0, mapped_len as SIZE_T);
CloseHandle(mapping);
if ptr.is_null() {
return Err(io::Error::last_os_error());
}
let mut old = 0;
let result = VirtualProtect(ptr, mapped_len as SIZE_T, PAGE_READWRITE, &mut old);
if result != 0 {
Ok(MmapInner {
handle: None,
ptr,
len: len as usize,
copy: false,
})
} else {
Err(io::Error::last_os_error())
}
}
}
pub fn flush(&self, offset: usize, len: usize) -> io::Result<()> {
self.flush_async(offset, len)?;
if let Some(handle) = self.handle {
let ok = unsafe { FlushFileBuffers(handle) };
if ok == 0 {
return Err(io::Error::last_os_error());
}
}
Ok(())
}
pub fn flush_async(&self, offset: usize, len: usize) -> io::Result<()> {
if self.ptr == empty_slice_ptr() {
return Ok(());
}
let result = unsafe { FlushViewOfFile(self.ptr.add(offset), len as SIZE_T) };
if result != 0 {
Ok(())
} else {
Err(io::Error::last_os_error())
}
}
fn virtual_protect(&mut self, protect: DWORD) -> io::Result<()> {
if self.ptr == empty_slice_ptr() {
return Ok(());
}
unsafe {
let alignment = self.ptr as usize % allocation_granularity();
let ptr = self.ptr.offset(-(alignment as isize));
let aligned_len = self.len as SIZE_T + alignment as SIZE_T;
let mut old = 0;
let result = VirtualProtect(ptr, aligned_len, protect, &mut old);
if result != 0 {
Ok(())
} else {
Err(io::Error::last_os_error())
}
}
}
pub fn make_read_only(&mut self) -> io::Result<()> {
self.virtual_protect(PAGE_READONLY)
}
pub fn make_exec(&mut self) -> io::Result<()> {
if self.copy {
self.virtual_protect(PAGE_EXECUTE_WRITECOPY)
} else {
self.virtual_protect(PAGE_EXECUTE_READ)
}
}
pub fn make_mut(&mut self) -> io::Result<()> {
if self.copy {
self.virtual_protect(PAGE_WRITECOPY)
} else {
self.virtual_protect(PAGE_READWRITE)
}
}
#[inline]
pub fn ptr(&self) -> *const u8 {
self.ptr as *const u8
}
#[inline]
pub fn mut_ptr(&mut self) -> *mut u8 {
self.ptr as *mut u8
}
#[inline]
pub fn len(&self) -> usize {
self.len
}
}
impl Drop for MmapInner {
fn drop(&mut self) {
if self.ptr == empty_slice_ptr() {
return;
}
let alignment = self.ptr as usize % allocation_granularity();
// Any errors during unmapping/closing are ignored as the only way
// to report them would be through panicking which is highly discouraged
// in Drop impls, c.f. https://github.com/rust-lang/lang-team/issues/97
unsafe {
let ptr = self.ptr.offset(-(alignment as isize));
UnmapViewOfFile(ptr);
if let Some(handle) = self.handle {
CloseHandle(handle);
}
}
}
}
unsafe impl Sync for MmapInner {}
unsafe impl Send for MmapInner {}
fn protection_supported(handle: RawHandle, protection: DWORD) -> bool {
unsafe {
let mapping = CreateFileMappingW(handle, ptr::null_mut(), protection, 0, 0, ptr::null());
if mapping.is_null() {
return false;
}
CloseHandle(mapping);
true
}
}
fn allocation_granularity() -> usize {
unsafe {
let mut info = mem::zeroed();
GetSystemInfo(&mut info);
info.dwAllocationGranularity as usize
}
}
pub fn file_len(handle: RawHandle) -> io::Result {
// SAFETY: We must not close the passed-in fd by dropping the File we create,
// we ensure this by immediately wrapping it in a ManuallyDrop.
unsafe {
let file = ManuallyDrop::new(File::from_raw_handle(handle));
Ok(file.metadata()?.len())
}
}