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mozilla-central/third_party/rust/bitreader/src/tests.rs

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// 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

});