Initial import of bitreader-0.3.6 am: 7016150b58 am: ec3462a199
Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/bitreader/+/2287737
Change-Id: I8328ba5d4cc440e6f44a4cdfbfc6513706b158f8
Signed-off-by: Automerger Merge Worker <[email protected]>
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..4ec13d2
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,27 @@
+[package]
+name = "bitreader"
+version = "0.3.6"
+authors = ["Ilkka Rauta <[email protected]>"]
+
+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"]
diff --git a/Cargo.toml.orig b/Cargo.toml.orig
new file mode 100644
index 0000000..4ec13d2
--- /dev/null
+++ b/Cargo.toml.orig
@@ -0,0 +1,27 @@
+[package]
+name = "bitreader"
+version = "0.3.6"
+authors = ["Ilkka Rauta <[email protected]>"]
+
+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"]
diff --git a/LICENSE b/LICENSE
new file mode 120000
index 0000000..6b579aa
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1 @@
+LICENSE-APACHE
\ No newline at end of file
diff --git a/LICENSE-APACHE b/LICENSE-APACHE
new file mode 100644
index 0000000..d645695
--- /dev/null
+++ b/LICENSE-APACHE
@@ -0,0 +1,202 @@
+
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+ http://www.apache.org/licenses/
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diff --git a/METADATA b/METADATA
new file mode 100644
index 0000000..8884e7f
--- /dev/null
+++ b/METADATA
@@ -0,0 +1,20 @@
+name: "bitreader"
+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."
+third_party {
+ url {
+ type: HOMEPAGE
+ value: "https://crates.io/crates/bitreader"
+ }
+ url {
+ type: ARCHIVE
+ value: "https://static.crates.io/crates/bitreader/bitreader-0.3.6.crate"
+ }
+ version: "0.3.6"
+ # Dual-licensed, using the least restrictive per go/thirdpartylicenses#same.
+ license_type: NOTICE
+ last_upgrade_date {
+ year: 2022
+ month: 11
+ day: 2
+ }
+}
diff --git a/MODULE_LICENSE_APACHE2 b/MODULE_LICENSE_APACHE2
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/MODULE_LICENSE_APACHE2
diff --git a/OWNERS b/OWNERS
new file mode 100644
index 0000000..45dc4dd
--- /dev/null
+++ b/OWNERS
@@ -0,0 +1 @@
+include platform/prebuilts/rust:master:/OWNERS
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..36ffd56
--- /dev/null
+++ b/README.md
@@ -0,0 +1,27 @@
+# BitReader
+
+BitReader is a helper type to extract strings of bits from a slice of bytes.
+
+[](https://crates.io/crates/bitreader)
+[](https://docs.rs/bitreader)
+[](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.
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..6c85391
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,472 @@
+// Copyright 2015 Ilkka Rauta
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, 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<u8> {
+ 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<u8> {
+ 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<u16> {
+ 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<u16> {
+ 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<u32> {
+ 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<u32> {
+ 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<u64> {
+ 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<u64> {
+ 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<i8> {
+ 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<i16> {
+ 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<i32> {
+ 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<i64> {
+ 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<bool> {
+ 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<bool> {
+ 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<i64> {
+ 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<u64> {
+ 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<T> = result::Result<T, BitReaderError>;
+
+/// 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<Self>;
+}
+
+// There's eight almost identical implementations, let's make this easier.
+macro_rules! impl_read_into {
+ ($T:ty, $method:ident) => (
+ impl ReadInto for $T {
+ fn read(reader: &mut BitReader, bits: u8) -> Result<Self> {
+ reader.$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<Self> {
+ match reader.read_u8(bits)? {
+ 0 => Ok(false),
+ _ => Ok(true),
+ }
+ }
+}
diff --git a/src/tests.rs b/src/tests.rs
new file mode 100644
index 0000000..f91a23b
--- /dev/null
+++ b/src/tests.rs
@@ -0,0 +1,316 @@
+// Copyright 2015 Ilkka Rauta
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, 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);
+ }
+}
+
+#[test]
+fn boolean_values() {
+ let bytes: Vec<u8> = (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
+ });
+}
