bitreader-0.3.7/.cargo_vcs_info.json0000644000000001360000000000100130040ustar { "git": { "sha1": "49ad34c52118beb3fc6d2c609a01101a82263a52" }, "path_in_vcs": "" }bitreader-0.3.7/.github/workflows/rust.yml000064400000000000000000000005011046102023000167050ustar 00000000000000name: build on: push: branches: [ "master" ] pull_request: branches: [ "master" ] env: CARGO_TERM_COLOR: always jobs: build: runs-on: ubuntu-latest steps: - uses: actions/checkout@v3 - name: Build run: cargo build --verbose - name: Run tests run: cargo test --verbose bitreader-0.3.7/.gitignore000064400000000000000000000000301046102023000135550ustar 00000000000000target Cargo.lock .idea bitreader-0.3.7/Cargo.toml0000644000000021540000000000100110040ustar # 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] name = "bitreader" version = "0.3.7" authors = ["Ilkka Rauta "] description = """ BitReader helps reading individual bits from a slice of bytes. You can read \"unusual\" numbers of bits from the byte slice, for example 13 bits at once. The reader internally keeps track of position within the buffer. """ homepage = "https://github.com/irauta/bitreader" documentation = "https://docs.rs/bitreader" readme = "README.md" keywords = [ "bit", "bits", "bitstream", ] license = "MIT OR Apache-2.0" repository = "https://github.com/irauta/bitreader" [dependencies.cfg-if] version = "1" [features] default = ["std"] std = [] bitreader-0.3.7/Cargo.toml.orig000064400000000000000000000011601046102023000144610ustar 00000000000000[package] name = "bitreader" version = "0.3.7" authors = ["Ilkka Rauta "] description = """ BitReader helps reading individual bits from a slice of bytes. You can read "unusual" numbers of bits from the byte slice, for example 13 bits at once. The reader internally keeps track of position within the buffer. """ documentation = "https://docs.rs/bitreader" homepage = "https://github.com/irauta/bitreader" repository = "https://github.com/irauta/bitreader" keywords = ["bit", "bits", "bitstream"] license = "MIT OR Apache-2.0" [dependencies] cfg-if = "1" [features] std = [] default = ["std"] bitreader-0.3.7/LICENSE-APACHE000064400000000000000000000261361046102023000135300ustar 00000000000000 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. 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See the License for the specific language governing permissions and limitations under the License. bitreader-0.3.7/LICENSE-MIT000064400000000000000000000020371046102023000132320ustar 00000000000000Copyright (c) 2015 Ilkka Rauta 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. bitreader-0.3.7/README.md000064400000000000000000000024611046102023000130560ustar 00000000000000# BitReader BitReader is a helper type to extract strings of bits from a slice of bytes. [![Published Package](https://img.shields.io/crates/v/bitreader.svg)](https://crates.io/crates/bitreader) [![Documentation](https://docs.rs/bitreader/badge.svg)](https://docs.rs/bitreader) [![Build Status](https://github.com/irauta/bitreader/actions/workflows/rust.yml/badge.svg?branch=master)](https://github.com/irauta/bitreader/actions/workflows/rust.yml) Here is how you read first a single bit, then three bits and finally four bits from a byte buffer: use bitreader::BitReader; let slice_of_u8 = &[0b1000_1111]; let mut reader = BitReader::new(slice_of_u8); // You obviously should use try! or some other error handling mechanism here let a_single_bit = reader.read_u8(1).unwrap(); // 1 let more_bits = reader.read_u8(3).unwrap(); // 0 let last_bits_of_byte = reader.read_u8(4).unwrap(); // 0b1111 You can naturally read bits from longer buffer of data than just a single byte. As you read bits, the internal cursor of BitReader moves on along the stream of bits. Big endian format is assumed when reading the multi-byte values. BitReader supports reading maximum of 64 bits at a time (with read_u64). ## License Licensed under the Apache License, Version 2.0 or the MIT license, at your option. bitreader-0.3.7/src/lib.rs000064400000000000000000000414051046102023000135030ustar 00000000000000// Copyright 2015 Ilkka Rauta // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. //! BitReader is a helper type to extract strings of bits from a slice of bytes. //! //! Here is how you read first a single bit, then three bits and finally four bits from a byte //! buffer: //! //! ``` //! use bitreader::BitReader; //! //! let slice_of_u8 = &[0b1000_1111]; //! let mut reader = BitReader::new(slice_of_u8); //! //! // You probably should use try! or some other error handling mechanism in real code if the //! // length of the input is not known in advance. //! let a_single_bit = reader.read_u8(1).unwrap(); //! assert_eq!(a_single_bit, 1); //! //! let more_bits = reader.read_u8(3).unwrap(); //! assert_eq!(more_bits, 0); //! //! let last_bits_of_byte = reader.read_u8(4).unwrap(); //! assert_eq!(last_bits_of_byte, 0b1111); //! ``` //! You can naturally read bits from longer buffer of data than just a single byte. //! //! As you read bits, the internal cursor of BitReader moves on along the stream of bits. Big //! endian format is assumed when reading the multi-byte values. BitReader supports reading maximum //! of 64 bits at a time (with read_u64). Reading signed values directly is not supported at the //! moment. //! //! The reads do not need to be aligned in any particular way. //! //! Reading zero bits is a no-op. //! //! You can also skip over a number of bits, in which case there is no arbitrary small limits like //! when reading the values to a variable. However, you can not seek past the end of the slice, //! either when reading or when skipping bits. //! //! Note that the code will likely not work correctly if the slice is longer than 2^61 bytes, but //! exceeding that should be pretty unlikely. Let's get back to this when people read exabytes of //! information one bit at a time. #![no_std] cfg_if::cfg_if!{ if #[cfg(feature = "std")] { extern crate std; use std::cmp::min; use std::prelude::v1::*; use std::fmt; use std::error::Error; use std::result; } else { use core::result; use core::fmt; use core::cmp::min; } } #[cfg(test)] mod tests; /// BitReader reads data from a byte slice at the granularity of a single bit. pub struct BitReader<'a> { bytes: &'a [u8], /// Position from the start of the slice, counted as bits instead of bytes position: u64, relative_offset: u64, /// Length this reader is allowed to read from the slice, counted as bits instead of bytes. length: u64, } impl<'a> BitReader<'a> { /// Construct a new BitReader from a byte slice. The returned reader lives at most as long as /// the slice given to is valid. pub fn new(bytes: &'a [u8]) -> BitReader<'a> { BitReader { bytes: bytes, position: 0, relative_offset: 0, length: bytes.len() as u64 * 8, } } /// Returns a copy of current BitReader, with the difference that its position() returns /// positions relative to the position of the original BitReader at the construction time. /// After construction, both readers are otherwise completely independent, except of course /// for sharing the same source data. /// /// ``` /// use bitreader::BitReader; /// /// let bytes = &[0b11110000, 0b00001111]; /// let mut original = BitReader::new(bytes); /// assert_eq!(original.read_u8(4).unwrap(), 0b1111); /// assert_eq!(original.position(), 4); /// /// let mut relative = original.relative_reader(); /// assert_eq!(relative.position(), 0); /// /// assert_eq!(original.read_u8(8).unwrap(), 0); /// assert_eq!(relative.read_u8(8).unwrap(), 0); /// /// assert_eq!(original.position(), 12); /// assert_eq!(relative.position(), 8); /// ``` pub fn relative_reader(&self) -> BitReader<'a> { BitReader { bytes: self.bytes, position: self.position, relative_offset: self.position, length: self.length - self.position, } } /// Returns a copy of current BitReader, with the difference that its position() returns /// positions relative to the position of the original BitReader at the construction time, and /// will not allow reading more than len bits. After construction, both readers are otherwise // completely independent, except of course for sharing the same source data. /// /// ``` /// use bitreader::BitReader; /// use bitreader::BitReaderError; /// /// let bytes = &[0b11110000, 0b00001111]; /// let mut original = BitReader::new(bytes); /// assert_eq!(original.read_u8(4).unwrap(), 0b1111); /// assert_eq!(original.position(), 4); /// /// let mut relative = original.relative_reader_atmost(8); /// assert_eq!(relative.position(), 0); /// /// assert_eq!(original.read_u8(8).unwrap(), 0); /// assert_eq!(relative.read_u8(8).unwrap(), 0); /// /// assert_eq!(original.position(), 12); /// assert_eq!(relative.position(), 8); /// /// assert_eq!(relative.read_u8(8).unwrap_err(), BitReaderError::NotEnoughData{ /// position: 8, /// length: 8, /// requested: 8 /// }); /// ``` pub fn relative_reader_atmost(&self, len: u64) -> BitReader<'a> { BitReader { bytes: self.bytes, position: self.position, relative_offset: self.position, length: min(self.length - self.position, len), } } /// Read at most 8 bits into a u8. pub fn read_u8(&mut self, bit_count: u8) -> Result { let value = self.read_value(bit_count, 8)?; Ok((value & 0xff) as u8) } /// Read at most 8 bits into a u8, but without moving the cursor forward. pub fn peek_u8(&self, bit_count: u8) -> Result { self.relative_reader().read_u8(bit_count) } /// Fills the entire `output_bytes` slice. If there aren't enough bits remaining /// after the internal cursor's current position, the cursor won't be moved forward /// and the contents of `output_bytes` won't be modified. pub fn read_u8_slice(&mut self, output_bytes: &mut [u8]) -> Result<()> { let requested = output_bytes.len() as u64 * 8; if requested > self.remaining() { Err(BitReaderError::NotEnoughData { position: self.position(), length: self.length, requested, }) } else { for byte in output_bytes.iter_mut() { *byte = self.read_u8(8)?; } Ok(()) } } /// Read at most 16 bits into a u16. pub fn read_u16(&mut self, bit_count: u8) -> Result { let value = self.read_value(bit_count, 16)?; Ok((value & 0xffff) as u16) } /// Read at most 16 bits into a u16, but without moving the cursor forward. pub fn peek_u16(&self, bit_count: u8) -> Result { self.relative_reader().read_u16(bit_count) } /// Read at most 32 bits into a u32. pub fn read_u32(&mut self, bit_count: u8) -> Result { let value = self.read_value(bit_count, 32)?; Ok((value & 0xffffffff) as u32) } /// Read at most 32 bits into a u32, but without moving the cursor forward. pub fn peek_u32(&self, bit_count: u8) -> Result { self.relative_reader().read_u32(bit_count) } /// Read at most 64 bits into a u64. pub fn read_u64(&mut self, bit_count: u8) -> Result { let value = self.read_value(bit_count, 64)?; Ok(value) } /// Read at most 64 bits into a u64, but without moving the cursor forward. pub fn peek_u64(&self, bit_count: u8) -> Result { self.relative_reader().read_u64(bit_count) } /// Read at most 8 bits into a i8. /// Assumes the bits are stored in two's complement format. pub fn read_i8(&mut self, bit_count: u8) -> Result { let value = self.read_signed_value(bit_count, 8)?; Ok((value & 0xff) as i8) } /// Read at most 16 bits into a i16. /// Assumes the bits are stored in two's complement format. pub fn read_i16(&mut self, bit_count: u8) -> Result { let value = self.read_signed_value(bit_count, 16)?; Ok((value & 0xffff) as i16) } /// Read at most 32 bits into a i32. /// Assumes the bits are stored in two's complement format. pub fn read_i32(&mut self, bit_count: u8) -> Result { let value = self.read_signed_value(bit_count, 32)?; Ok((value & 0xffffffff) as i32) } /// Read at most 64 bits into a i64. /// Assumes the bits are stored in two's complement format. pub fn read_i64(&mut self, bit_count: u8) -> Result { let value = self.read_signed_value(bit_count, 64)?; Ok(value) } /// Read a single bit as a boolean value. /// Interprets 1 as true and 0 as false. pub fn read_bool(&mut self) -> Result { match self.read_value(1, 1)? { 0 => Ok(false), _ => Ok(true), } } /// Read a single bit as a boolean value, but without moving the cursor forward. /// Interprets 1 as true and 0 as false. pub fn peek_bool(&self) -> Result { self.relative_reader().read_bool() } /// Skip arbitrary number of bits. However, you can skip at most to the end of the byte slice. pub fn skip(&mut self, bit_count: u64) -> Result<()> { let end_position = self.position + bit_count; if end_position > (self.relative_offset + self.length) { return Err(BitReaderError::NotEnoughData { position: self.position(), length: self.length, requested: bit_count, }); } self.position = end_position; Ok(()) } /// Returns the position of the cursor, or how many bits have been read so far. pub fn position(&self) -> u64 { self.position - self.relative_offset } /// Returns the number of bits not yet read from the underlying slice. pub fn remaining(&self) -> u64 { self.length - self.position } /// Helper to make sure the "bit cursor" is exactly at the beginning of a byte, or at specific /// multi-byte alignment position. /// /// For example `reader.is_aligned(1)` returns true if exactly n bytes, or n * 8 bits, has been /// read. Similarly, `reader.is_aligned(4)` returns true if exactly n * 32 bits, or n 4-byte /// sequences has been read. /// /// This function can be used to validate the data is being read properly, for example by /// adding invocations wrapped into `debug_assert!()` to places where it is known the data /// should be n-byte aligned. pub fn is_aligned(&self, alignment_bytes: u32) -> bool { self.position % (alignment_bytes as u64 * 8) == 0 } /// Helper to move the "bit cursor" to exactly the beginning of a byte, or to a specific /// multi-byte alignment position. /// /// That is, `reader.align(n)` moves the cursor to the next position that /// is a multiple of n * 8 bits, if it's not correctly aligned already. pub fn align(&mut self, alignment_bytes: u32) -> Result<()> { let alignment_bits = alignment_bytes as u64 * 8; let cur_alignment = self.position % alignment_bits; let bits_to_skip = (alignment_bits - cur_alignment) % alignment_bits; self.skip(bits_to_skip) } fn read_signed_value(&mut self, bit_count: u8, maximum_count: u8) -> Result { if bit_count == 0 { return Ok(0); } let unsigned = self.read_value(bit_count, maximum_count)?; // Fill the bits above the requested bits with all ones or all zeros, // depending on the sign bit. let sign_bit = unsigned >> (bit_count - 1) & 1; let high_bits = if sign_bit == 1 { -1 } else { 0 }; Ok(high_bits << bit_count | unsigned as i64) } fn read_value(&mut self, bit_count: u8, maximum_count: u8) -> Result { if bit_count == 0 { return Ok(0); } if bit_count > maximum_count { return Err(BitReaderError::TooManyBitsForType { position: self.position, requested: bit_count, allowed: maximum_count, }); } let start_position = self.position; let end_position = self.position + bit_count as u64; if end_position > (self.relative_offset + self.length) { return Err(BitReaderError::NotEnoughData { position: self.position(), length: self.length, requested: bit_count as u64, }); } let mut value: u64 = 0; for i in start_position..end_position { let byte_index = (i / 8) as usize; let byte = self.bytes[byte_index]; let shift = 7 - (i % 8); let bit = (byte >> shift) as u64 & 1; value = (value << 1) | bit; } self.position = end_position; Ok(value) } } /// Result type for those BitReader operations that can fail. pub type Result = result::Result; /// Error enumeration of BitReader errors. #[derive(Debug,PartialEq,Copy,Clone)] pub enum BitReaderError { /// Requested more bits than there are left in the byte slice at the current position. NotEnoughData { /// Current posititon in bits relative to the beginning of the reader. position: u64, /// Total readable length in bits of the underlaying slice. length: u64, /// Bits requested to be read. requested: u64, }, /// Requested more bits than the returned variable can hold, for example more than 8 bits when /// reading into a u8. TooManyBitsForType { position: u64, requested: u8, allowed: u8, } } #[cfg(feature = "std")] impl Error for BitReaderError { fn description(&self) -> &str { match *self { BitReaderError::NotEnoughData {..} => "Requested more bits than the byte slice has left", BitReaderError::TooManyBitsForType {..} => "Requested more bits than the requested integer type can hold", } } } impl fmt::Display for BitReaderError { fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { //self.description().fmt(fmt) match *self { BitReaderError::NotEnoughData { position, length, requested } => write!(fmt, "BitReader: Requested {} bits with only {}/{} bits left (position {})", requested, length - position, length, position), BitReaderError::TooManyBitsForType { position, requested, allowed } => write!(fmt, "BitReader: Requested {} bits while the type can only hold {} (position {})", requested, allowed, position), } } } /// Helper trait to allow reading bits into a variable without explicitly mentioning its type. /// /// If you can't or want, for some reason, to use BitReader's read methods (`read_u8` etc.) but /// want to rely on type inference instead, you can use the ReadInto trait. The trait is /// implemented for all basic integer types (8/16/32/64 bits, signed/unsigned) /// and the boolean type. /// /// ``` /// use bitreader::{BitReader,ReadInto}; /// /// let slice_of_u8 = &[0b1110_0000]; /// let mut reader = BitReader::new(slice_of_u8); /// /// struct Foo { /// bar: u8, /// valid: bool, /// } /// /// // No type mentioned here, instead the type of bits is inferred from the type of Foo::bar, /// // and consequently the correct "overload" is used. /// let bits = ReadInto::read(&mut reader, 2).unwrap(); /// let valid = ReadInto::read(&mut reader, 1).unwrap(); /// /// let foo = Foo { bar: bits, valid: valid }; /// assert_eq!(foo.bar, 3); /// assert!(foo.valid); /// ``` pub trait ReadInto where Self: Sized { fn read(reader: &mut BitReader, bits: u8) -> Result; } // There's eight almost identical implementations, let's make this easier. macro_rules! impl_read_into { ($T:ty, $method:ident) => ( impl ReadInto for $T { fn read(reader: &mut BitReader, bits: u8) -> Result { reader.$method(bits) } } ) } impl_read_into!(u8, read_u8); impl_read_into!(u16, read_u16); impl_read_into!(u32, read_u32); impl_read_into!(u64, read_u64); impl_read_into!(i8, read_i8); impl_read_into!(i16, read_i16); impl_read_into!(i32, read_i32); impl_read_into!(i64, read_i64); // We can't cast to bool, so this requires a separate method. impl ReadInto for bool { fn read(reader: &mut BitReader, bits: u8) -> Result { match reader.read_u8(bits)? { 0 => Ok(false), _ => Ok(true), } } } bitreader-0.3.7/src/tests.rs000064400000000000000000000242241046102023000140770ustar 00000000000000// Copyright 2015 Ilkka Rauta // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. use super::*; #[test] fn read_buffer() { let bytes = &[ 0b1011_0101, 0b0110_1010, 0b1010_1100, 0b1001_1001, 0b1001_1001, 0b1001_1001, 0b1001_1001, 0b1110_0111, ]; let mut reader = BitReader::new(bytes); assert_eq!(reader.read_u8(1).unwrap(), 0b1); assert_eq!(reader.peek_u8(3).unwrap(), 0b011); assert_eq!(reader.read_u8(1).unwrap(), 0b0); assert_eq!(reader.read_u8(2).unwrap(), 0b11); assert!(!reader.is_aligned(1)); assert!(!reader.is_aligned(2)); assert!(!reader.is_aligned(4)); assert_eq!(reader.position(), 4); assert_eq!(reader.remaining(), 60); assert_eq!(reader.read_u8(4).unwrap(), 0b0101); assert!(reader.is_aligned(1)); assert!(!reader.is_aligned(2)); assert!(!reader.is_aligned(4)); assert_eq!(reader.align(1), Ok(())); // shouldn't do anything if already aligned assert_eq!(reader.peek_u64(16).unwrap(), 0b110_1010_1010_1100); assert_eq!(reader.read_u8(3).unwrap(), 0b11); assert_eq!(reader.peek_u16(13).unwrap(), 0b1010_1010_1100); assert_eq!(reader.peek_u32(13).unwrap(), 0b1010_1010_1100); assert_eq!(reader.peek_u64(13).unwrap(), 0b1010_1010_1100); assert_eq!(reader.peek_u16(10).unwrap(), 0b01_0101_0101); assert_eq!(reader.peek_u8(8).unwrap(), 0b0101_0101); assert_eq!(reader.read_u16(10).unwrap(), 0b01_0101_0101); assert_eq!(reader.read_u8(3).unwrap(), 0b100); assert_eq!(reader.position(), 24); assert_eq!(reader.remaining(), 40); assert!(reader.is_aligned(1)); assert_eq!(reader.read_u32(32).unwrap(), 0b1001_1001_1001_1001_1001_1001_1001_1001); assert_eq!(reader.peek_bool().unwrap(), true); assert_eq!(reader.read_u8(4).unwrap(), 0b1110); assert_eq!(reader.peek_bool().unwrap(), false); assert_eq!(reader.read_u8(3).unwrap(), 0b011); assert_eq!(reader.peek_bool().unwrap(), true); assert_eq!(reader.read_bool().unwrap(), true); // Could also be 8 at this point! assert!(reader.is_aligned(4)); // shouldn't do anything if already aligned assert_eq!(reader.align(1), Ok(())); assert_eq!(reader.align(2), Ok(())); assert_eq!(reader.align(4), Ok(())); assert_eq!(reader.align(8), Ok(())); // Start over to test align() let mut reader = BitReader::new(bytes); // shouldn't do anything if already aligned assert_eq!(reader.align(1), Ok(())); assert_eq!(reader.align(2), Ok(())); assert_eq!(reader.align(4), Ok(())); assert_eq!(reader.align(8), Ok(())); assert_eq!(reader.position(), 0); assert_eq!(reader.read_u8(1).unwrap(), 0b1); assert_eq!(reader.align(1), Ok(())); assert_eq!(reader.position(), 8); assert!(reader.is_aligned(1)); assert!(!reader.is_aligned(2)); assert!(!reader.is_aligned(4)); assert_eq!(reader.align(2), Ok(())); assert_eq!(reader.position(), 16); assert!(reader.is_aligned(1)); assert!(reader.is_aligned(2)); assert!(!reader.is_aligned(4)); assert_eq!(reader.read_u8(7).unwrap(), 0b0101_0110); assert_eq!(reader.align(4), Ok(())); assert_eq!(reader.position(), 32); assert!(reader.is_aligned(1)); assert!(reader.is_aligned(2)); assert!(reader.is_aligned(4)); let mut reader = BitReader::new(bytes); assert_eq!(reader.position(), 0); assert_eq!(reader.skip(1), Ok(())); assert_eq!(reader.align(4), Ok(())); assert_eq!(reader.position(), 32); assert_eq!(reader.skip(7), Ok(())); assert_eq!(reader.align(1), Ok(())); assert_eq!(reader.position(), 40); assert_eq!(reader.align(2), Ok(())); assert_eq!(reader.position(), 48); assert_eq!(reader.skip(5), Ok(())); assert_eq!(reader.align(2), Ok(())); assert_eq!(reader.position(), 64); let mut reader = BitReader::new(bytes); assert_eq!(reader.skip(1), Ok(())); assert_eq!(reader.align(3), Ok(())); assert_eq!(reader.position(), 24); assert!(!reader.align(128).is_ok()); } #[test] fn try_all_sizes() { let bytes = &[ 0x4a, 0x1e, 0x39, 0xbb, 0xd0, 0x07, 0xca, 0x9a, 0xa6, 0xba, 0x25, 0x52, 0x6f, 0x0a, 0x6a, 0xba, ]; let mut reader = BitReader::new(bytes); assert_eq!(reader.read_u64(64).unwrap(), 0x4a1e39bbd007ca9a); assert_eq!(reader.read_u64(64).unwrap(), 0xa6ba25526f0a6aba); let mut reader = BitReader::new(bytes); assert_eq!(reader.read_u32(32).unwrap(), 0x4a1e39bb); assert_eq!(reader.read_u32(32).unwrap(), 0xd007ca9a); assert_eq!(reader.read_u32(32).unwrap(), 0xa6ba2552); assert_eq!(reader.read_u32(32).unwrap(), 0x6f0a6aba); let mut reader = BitReader::new(bytes); assert_eq!(reader.read_u16(16).unwrap(), 0x4a1e); assert_eq!(reader.read_u16(16).unwrap(), 0x39bb); assert_eq!(reader.read_u16(16).unwrap(), 0xd007); assert_eq!(reader.read_u16(16).unwrap(), 0xca9a); assert_eq!(reader.read_u16(16).unwrap(), 0xa6ba); assert_eq!(reader.read_u16(16).unwrap(), 0x2552); assert_eq!(reader.read_u16(16).unwrap(), 0x6f0a); assert_eq!(reader.read_u16(16).unwrap(), 0x6aba); let mut reader = BitReader::new(&bytes[..]); for byte in bytes { assert_eq!(reader.read_u8(8).unwrap(), *byte); } } #[test] fn skipping_and_zero_reads() { let bytes = &[ 0b1011_0101, 0b1110_1010, 0b1010_1100, 0b0011_0101, ]; let mut reader = BitReader::new(bytes); assert_eq!(reader.read_u8(4).unwrap(), 0b1011); // Reading zero bits should be a no-op assert_eq!(reader.read_u8(0).unwrap(), 0b0); assert_eq!(reader.read_i8(0).unwrap(), 0b0); assert_eq!(reader.read_u8(4).unwrap(), 0b0101); reader.skip(3).unwrap(); // 0b111 assert_eq!(reader.read_u16(10).unwrap(), 0b0101010101); assert_eq!(reader.read_u8(3).unwrap(), 0b100); reader.skip(4).unwrap(); // 0b0011 assert_eq!(reader.read_u32(2).unwrap(), 0b01); assert_eq!(reader.read_bool().unwrap(), false); assert_eq!(reader.read_bool().unwrap(), true); } #[test] fn errors() { let bytes = &[ 0b1011_0101, 0b1110_1010, 0b1010_1100, ]; let mut reader = BitReader::new(bytes); assert_eq!(reader.read_u8(4).unwrap(), 0b1011); assert_eq!(reader.read_u8(9).unwrap_err(), BitReaderError::TooManyBitsForType { position: 4, requested: 9, allowed: 8 }); // If an error happens, it should be possible to resume as if nothing had happened assert_eq!(reader.read_u8(4).unwrap(), 0b0101); let mut reader = BitReader::new(bytes); assert_eq!(reader.read_u8(4).unwrap(), 0b1011); // Same with this error assert_eq!(reader.read_u32(21).unwrap_err(), BitReaderError::NotEnoughData { position: 4, length: (bytes.len() * 8) as u64, requested: 21 }); assert_eq!(reader.read_u8(4).unwrap(), 0b0101); } #[test] fn signed_values() { let from = -2048; let to = 2048; for x in from..to { let bytes = &[ (x >> 8) as u8, x as u8, ]; let mut reader = BitReader::new(bytes); assert_eq!(reader.read_u8(4).unwrap(), if x < 0 { 0b1111 } else { 0 }); assert_eq!(reader.read_i16(12).unwrap(), x); } } #[cfg(feature = "std")] #[test] fn boolean_values() { let bytes: Vec = (0..16).collect(); let mut reader = BitReader::new(&bytes); for v in &bytes { assert_eq!(reader.read_bool().unwrap(), false); reader.skip(3).unwrap(); assert_eq!(reader.read_bool().unwrap(), v & 0x08 == 8); assert_eq!(reader.read_bool().unwrap(), v & 0x04 == 4); assert_eq!(reader.read_bool().unwrap(), v & 0x02 == 2); assert_eq!(reader.read_bool().unwrap(), v & 0x01 == 1); } } #[test] fn read_slice() { let bytes = &[ 0b1111_0000, 0b0000_1111, 0b1111_0000, 0b0000_1000, 0b0000_0100, 0b0000_0011, 0b1111_1100, 0b0000_0011, 0b1101_1000, ]; let mut reader = BitReader::new(bytes); assert_eq!(reader.read_u8(4).unwrap(), 0b1111); // Just some pattern that's definitely not in the bytes array let mut output = [0b1010_1101; 3]; reader.read_u8_slice(&mut output).unwrap(); assert_eq!(&output, &[0u8, 255u8, 0u8]); assert_eq!(reader.read_u8(1).unwrap(), 1); reader.read_u8_slice(&mut output[1..2]).unwrap(); assert_eq!(&output, &[0u8, 0u8, 0u8]); assert_eq!(reader.read_u8(1).unwrap(), 1); output = [0b1010_1101; 3]; reader.read_u8_slice(&mut output).unwrap(); assert_eq!(&output, &[0u8, 255u8, 0u8]); reader.read_u8_slice(&mut output[0..1]).unwrap(); assert_eq!(output[0], 0b1111_0110); assert_eq!(reader.read_u8(2).unwrap(), 0); } #[test] fn read_slice_too_much() { let bytes = &[ 0b1111_1111, 0b1111_1111, 0b1111_1111, 0b1111_1111, ]; let mut reader = BitReader::new(bytes); assert_eq!(reader.read_u8(1).unwrap(), 1); let mut output = [0u8; 4]; let should_be_error = reader.read_u8_slice(&mut output); assert_eq!(should_be_error.unwrap_err(), BitReaderError::NotEnoughData { position: 1, length: (bytes.len() * 8) as u64, requested: (&output.len() * 8) as u64 }); assert_eq!(&output, &[0u8; 4]); } #[test] fn relative_reader() { let bytes = &[ 0b0001_0010, 0b0011_0100, ]; let mut reader = BitReader::new(bytes); assert_eq!(reader.read_u8(4).unwrap(), 0b0001); let mut relative_reader = reader.relative_reader(); assert_eq!(reader.read_u8(4).unwrap(), 0b0010); assert_eq!(reader.read_u8(4).unwrap(), 0b0011); assert_eq!(reader.read_u8(4).unwrap(), 0b0100); assert_eq!(reader.read_u8(1).unwrap_err(), BitReaderError::NotEnoughData { position: 16, length: 16, requested: 1 }); assert_eq!(relative_reader.read_u8(4).unwrap(), 0b0010); assert_eq!(relative_reader.read_u8(4).unwrap(), 0b0011); assert_eq!(relative_reader.read_u8(4).unwrap(), 0b0100); assert_eq!(relative_reader.read_u8(1).unwrap_err(), BitReaderError::NotEnoughData { position: 12, length: 12, requested: 1 }); }