brotli-no-stdlib 1.0.4

#![allow(non_snake_case)]
use core::default::Default;
macro_rules! xprintln (
  ($a : expr) => ();
  ($a : expr, $b : expr) => ();
  ($a : expr, $b : expr, $c : expr) => ();
  ($a : expr, $b : expr, $c : expr, $d : expr) => ();
  ($a : expr, $b : expr, $c : expr, $d : expr, $e : expr) => ();
  ($a : expr, $b : expr, $c : expr, $d : expr, $e : expr, $f : expr) => ();
);

pub const BROTLI_SHORT_FILL_BIT_WINDOW_READ : u32 = 4;

#[allow(non_camel_case_types)]
pub type reg_t = u64;

#[allow(non_upper_case_globals)]
const kBitMask : [u32;33] = [ 0x0000,
    0x00000001, 0x00000003, 0x00000007, 0x0000000F,
    0x0000001F, 0x0000003F, 0x0000007F, 0x000000FF,
    0x000001FF, 0x000003FF, 0x000007FF, 0x00000FFF,
    0x00001FFF, 0x00003FFF, 0x00007FFF, 0x0000FFFF,
    0x0001FFFF, 0x0003FFFF, 0x0007FFFF, 0x000FFFFF,
    0x001FFFFF, 0x003FFFFF, 0x007FFFFF, 0x00FFFFFF,
    0x01FFFFFF, 0x03FFFFFF, 0x07FFFFFF, 0x0FFFFFFF,
    0x1FFFFFFF, 0x3FFFFFFF, 0x7FFFFFFF, 0xFFFFFFFF
];

#[inline]
pub fn BitMask(n : u32) -> u32{
  if false {
    /* Masking with this expression turns to a single
       "Unsigned Bit Field Extract" UBFX instruction on ARM. */
    return !((0xffffffffu32) << n);
  } else {
    return kBitMask[n as usize];
  }
}

pub struct BrotliBitReader {
  pub val_ : reg_t,             /* pre-fetched bits */
  pub bit_pos_ : u32,       /* current bit-reading position in val_ */
  pub next_in : u32,  /* the byte we're reading from */
  pub avail_in : u32,
}

impl Default for BrotliBitReader {
    fn default() -> Self {
        return BrotliBitReader {
            val_ : 0,
            bit_pos_ : 0,
            next_in : 0,
            avail_in : 0,
        }
    }
}

pub struct BrotliBitReaderState {
  pub val_ : reg_t,             /* pre-fetched bits */
  pub bit_pos_ : u32,       /* current bit-reading position in val_ */
  pub next_in : u32,  /* the byte we're reading from */
  pub avail_in : u32,
}
impl Default for BrotliBitReaderState {
    #[inline]
    fn default() -> Self {
        return BrotliBitReaderState {
            val_ : 0,
            bit_pos_ : 0,
            next_in : 0,
            avail_in : 0,
        }
    }
}

pub fn BrotliBitReaderSaveState(
    from : &BrotliBitReader) -> BrotliBitReaderState {

  return BrotliBitReaderState { val_ : from.val_,
                              bit_pos_ : from.bit_pos_,
                              next_in : from.next_in,
                              avail_in : from.avail_in };
}

pub fn BrotliBitReaderRestoreState(
    to : &mut BrotliBitReader, from : &BrotliBitReaderState) {
  to.val_ = from.val_;
  to.bit_pos_ = from.bit_pos_;
  to.next_in = from.next_in;
  to.avail_in = from.avail_in;
}

pub fn BrotliGetAvailableBits(
    br: &BrotliBitReader) -> u32{
  return ((::core::mem::size_of::<reg_t>() as u32) << 3) - br.bit_pos_;
}

/* Returns amount of unread bytes the bit reader still has buffered from the
   BrotliInput, including whole bytes in br->val_. */
pub fn BrotliGetRemainingBytes(br : &BrotliBitReader) -> u32 {
  return br.avail_in + (BrotliGetAvailableBits(br) >> 3);
}

/* Checks if there is at least num bytes left in the input ringbuffer (excluding
   the bits remaining in br->val_). */
pub fn BrotliCheckInputAmount(
    br : &BrotliBitReader, num: u32) -> bool{
  return br.avail_in >= num;
}



fn BrotliLoad16LE(input : &[u8], next_in_u32 : u32) -> u16 {
  let next_in : usize = next_in_u32 as usize;
  let mut two_byte : [u8; 2] = [0;2];
  two_byte.clone_from_slice(&input[next_in..next_in + 2]);
  return (two_byte[0] as u16) | ((two_byte[1] as u16) << 8);
}

fn BrotliLoad32LE(input : &[u8], next_in_u32 : u32) -> u32 {
  let next_in : usize = next_in_u32 as usize;
  let mut four_byte : [u8; 4] = [0;4];
  four_byte.clone_from_slice(&input[next_in..next_in + 4]);
  return (four_byte[0] as u32) | ((four_byte[1] as u32) << 8)
      | ((four_byte[2] as u32) << 16) | ((four_byte[3] as u32) << 24);
}

fn BrotliLoad64LE(input : &[u8], next_in_u32 : u32) -> u64 {
  let next_in : usize = next_in_u32 as usize;
  let mut eight_byte : [u8; 8] = [0;8];
  eight_byte.clone_from_slice(&input[next_in..next_in + 8]);
  return (eight_byte[0] as u64) | ((eight_byte[1] as u64) << 8)
      | ((eight_byte[2] as u64) << 16) | ((eight_byte[3] as u64) << 24)
      | ((eight_byte[4] as u64) << 32) | ((eight_byte[5] as u64) << 40)
      | ((eight_byte[6] as u64) << 48) | ((eight_byte[7] as u64) << 56);
}
pub const BROTLI_ALIGNED_READ : u8 = 0;

pub fn BrotliFillBitWindow(br : &mut BrotliBitReader, n_bits : u32, input : &[u8]) {
  if ::core::mem::size_of::<reg_t>() == 8 {
    if (n_bits <= 8) {
      if (BROTLI_ALIGNED_READ == 0 && br.bit_pos_ >= 56) {
        br.val_ >>= 56;
        br.bit_pos_ ^= 56;  // here same as -= 56 because of the if condition
        br.val_ |= BrotliLoad64LE(input, br.next_in) << 8;
        br.avail_in -= 7;
        br.next_in += 7;
      }
    } else if (BROTLI_ALIGNED_READ == 0 && n_bits <= 16) {
      if (br.bit_pos_ >= 48) {
        br.val_ >>= 48;
        br.bit_pos_ ^= 48;  // here same as -= 48 because of the if condition
        br.val_ |= BrotliLoad64LE(input, br.next_in) << 16;
        br.avail_in -= 6;
        br.next_in += 6;
      }
    } else if br.bit_pos_ >= 32 {
      br.val_ >>= 32;
      br.bit_pos_ ^= 32;  /* here same as -= 32 because of the if condition */
      br.val_ |= (BrotliLoad32LE(input, br.next_in) as reg_t) << 32;
      br.avail_in -= BROTLI_SHORT_FILL_BIT_WINDOW_READ;
      br.next_in += BROTLI_SHORT_FILL_BIT_WINDOW_READ;
    }
  } else {
    if (BROTLI_ALIGNED_READ == 0 && (n_bits <= 8)) {
      if (br.bit_pos_ >= 24) {
        br.val_ >>= 24;
        br.bit_pos_ ^= 24;  // here same as -= 24 because of the if condition
        br.val_ |= (BrotliLoad32LE(input, br.next_in) << 8) as u64;
        br.avail_in -= 3;
        br.next_in += 3;
      }
    } else {
      if br.bit_pos_ >= 16 {
        br.val_ >>= 16;
        br.bit_pos_ ^= 16;  /* here same as -= 16 because of the if condition */
        br.val_ |= (BrotliLoad16LE(input, br.next_in) as reg_t) << 16;
        br.avail_in -= BROTLI_SHORT_FILL_BIT_WINDOW_READ;
        br.next_in += BROTLI_SHORT_FILL_BIT_WINDOW_READ;
      }
    }
  }
}

#[inline(always)]
fn BrotliFillBitWindowCompileTimeNbits(br : &mut BrotliBitReader, n_bits : u32, input : &[u8]) {
  if ::core::mem::size_of::<reg_t>() == 8 {
    if BROTLI_ALIGNED_READ == 0 && n_bits <= 8 {// !BROTLI_ALIGNED_READ && IS_CONSTANT(n_bits) && (n_bits <= 8)) {
      if br.bit_pos_ >= 56 {
        br.val_ >>= 56;
        br.bit_pos_ ^= 56;  /* here same as -= 56 because of the if condition */
        br.val_ |= BrotliLoad64LE(input, br.next_in) << 8;
        br.avail_in -= 7;
        br.next_in += 7;
      }
    } else if BROTLI_ALIGNED_READ == 0 && n_bits <= 16 {// (!BROTLI_ALIGNED_READ && IS_CONSTANT(n_bits) && (n_bits <= 16)) {
      if br.bit_pos_ >= 48 {
        br.val_ >>= 48;
        br.bit_pos_ ^= 48;  /* here same as -= 48 because of the if condition */
        br.val_ |= BrotliLoad64LE(input, br.next_in) << 16;
        br.avail_in -= 6;
        br.next_in += 6;
      }
    } else {
      if br.bit_pos_ >= 32 {
        br.val_ >>= 32;
        br.bit_pos_ ^= 32;  /* here same as -= 32 because of the if condition */
        br.val_ |= (BrotliLoad32LE(input, br.next_in) as reg_t) << 32;
        br.avail_in -= BROTLI_SHORT_FILL_BIT_WINDOW_READ;
        br.next_in += BROTLI_SHORT_FILL_BIT_WINDOW_READ;
      }
    }
  } else {
    if /*BROTLI_ALIGNED_READ == false && */n_bits <= 8 { // !BROTLI_ALIGNED_READ && IS_CONSTANT(n_bits) && (n_bits <= 8)) {
      if br.bit_pos_ >= 24 {
        br.val_ >>= 24;
        br.bit_pos_ ^= 24;  /* here same as -= 24 because of the if condition */
        br.val_ |= (BrotliLoad32LE(input, br.next_in) as reg_t) << 8;
        br.avail_in -= 3;
        br.next_in += 3;
      }
    } else {
      if br.bit_pos_ >= 16 {
        br.val_ >>= 16;
        br.bit_pos_ ^= 16;  /* here same as -= 16 because of the if condition */
        br.val_ |= (BrotliLoad16LE(input, br.next_in) as reg_t) << 16;
        br.avail_in -= BROTLI_SHORT_FILL_BIT_WINDOW_READ;
        br.next_in += BROTLI_SHORT_FILL_BIT_WINDOW_READ;
      }
    }
  }
}

/* Mosltly like BrotliFillBitWindow, but guarantees only 16 bits and reads no
   more than BROTLI_SHORT_FILL_BIT_WINDOW_READ bytes of input. */
pub fn BrotliFillBitWindow16(br: &mut BrotliBitReader, input : &[u8]) {
  BrotliFillBitWindowCompileTimeNbits(br, 17, input);
}

/* Pulls one byte of input to accumulator. */
pub fn BrotliPullByte(br : &mut BrotliBitReader, input : &[u8]) -> bool {
  if br.avail_in == 0 {
    return false;
  }
  br.val_ >>= 8;
  if ::core::mem::size_of::<reg_t>() == 8 {
    br.val_ |= (input[br.next_in as usize] as reg_t) << 56;
  } else {
    br.val_ |= (input[br.next_in as usize] as reg_t) << 24;
  }
  br.bit_pos_ -= 8;
  br.avail_in -= 1;
  br.next_in += 1;
  return true;
}

/* Returns currently available bits.
   The number of valid bits could be calclulated by BrotliGetAvailableBits. */
#[inline]
pub fn BrotliGetBitsUnmasked(br : &BrotliBitReader) -> reg_t {
  return br.val_ >> br.bit_pos_;
}

/* Like BrotliGetBits, but does not mask the result.
   The result contains at least 16 valid bits. */
pub fn BrotliGet16BitsUnmasked(
    br : &mut BrotliBitReader,
    input : &[u8]) -> u32 {
  BrotliFillBitWindowCompileTimeNbits(br, 16, input);
  return (BrotliGetBitsUnmasked(br) & (0xffffffffu32 as reg_t)) as u32;
}

/* Returns the specified number of bits from br without advancing bit pos. */
pub fn BrotliGetBits(
    br : &mut BrotliBitReader, n_bits : u32, input : &[u8]) -> u32{
  BrotliFillBitWindow(br, n_bits, input);
  return (BrotliGetBitsUnmasked(br) as u32) & BitMask(n_bits);
}

/* Returns the specified number of bits from br without advancing bit pos. */
#[allow (dead_code)]
pub fn BrotliGetConstantNBits(
    br : &mut BrotliBitReader, n_bits : u32, input : &[u8]) -> u32{
  BrotliFillBitWindowCompileTimeNbits(br, n_bits, input);
  return (BrotliGetBitsUnmasked(br) as u32) & BitMask(n_bits);
}

/* Tries to peek the specified amount of bits. Returns 0, if there is not
   enough input. */
pub fn BrotliSafeGetBits(
    br : &mut BrotliBitReader, n_bits : u32, val : &mut u32, input : &[u8]) -> bool {
  while BrotliGetAvailableBits(br) < n_bits {
    if !BrotliPullByte(br, input) {
      return false;
    }
  }
  *val = (BrotliGetBitsUnmasked(br) as u32) & BitMask(n_bits);
  return true;
}

/* Advances the bit pos by n_bits. */
pub fn BrotliDropBits(
    br : &mut BrotliBitReader, n_bits : u32) {
  br.bit_pos_ += n_bits;
}

pub fn BrotliBitReaderUnload(br : &mut BrotliBitReader) {
  let unused_bytes : u32 = BrotliGetAvailableBits(br) >> 3;
  let unused_bits : u32 = unused_bytes << 3;
  br.avail_in += unused_bytes;
  br.next_in -= unused_bytes;
  if unused_bits as usize == (::core::mem::size_of::<reg_t>() << 3) {
    br.val_ = 0;
  } else {
    br.val_ <<= unused_bits;
  }
  br.bit_pos_ += unused_bits;
}

/* Reads the specified number of bits from br and advances the bit pos.
   Precondition: accumulator MUST contain at least n_bits. */
pub fn BrotliTakeBits(
  br : &mut BrotliBitReader, n_bits : u32, val : &mut u32) {
  *val = (BrotliGetBitsUnmasked(br) as u32) & BitMask(n_bits);
  //if true {
    xprintln!("[BrotliReadBits]  {:?} {:?} {:?} val: {:x}\n",
           br.avail_in, br.bit_pos_, n_bits, *val);
  //}
  BrotliDropBits(br, n_bits);
}

/* Reads the specified number of bits from br and advances the bit pos.
   Assumes that there is enough input to perform BrotliFillBitWindow. */
pub fn BrotliReadBits(
    br : &mut BrotliBitReader, n_bits : u32, input : &[u8]) -> u32{
  if ::core::mem::size_of::<reg_t>() == 8 || (n_bits <= 16) {
    let mut val : u32 = 0;
    BrotliFillBitWindow(br, n_bits, input);
    BrotliTakeBits(br, n_bits, &mut val);
    return val;
  } else {
    let mut low_val : u32 = 0;
    let mut high_val : u32 = 0;
    BrotliFillBitWindowCompileTimeNbits(br, 16, input);
    BrotliTakeBits(br, 16, &mut low_val);
    BrotliFillBitWindowCompileTimeNbits(br, 8, input);
    BrotliTakeBits(br, n_bits - 16, &mut high_val);
    return low_val | (high_val << 16);
  }
}

/* Reads the specified number of bits from br and advances the bit pos.
   Assumes that there is enough input to perform BrotliFillBitWindow. */
#[allow (dead_code)]
pub fn BrotliReadConstantNBits(
    br : &mut BrotliBitReader, n_bits : u32, input : &[u8]) -> u32{
  if ::core::mem::size_of::<reg_t>() == 8 || (n_bits <= 16) {
    let mut val : u32 = 0;
    BrotliFillBitWindowCompileTimeNbits(br, n_bits, input);
    BrotliTakeBits(br, n_bits, &mut val);
    return val;
  } else {
    let mut low_val : u32 = 0;
    let mut high_val : u32 = 0;
    BrotliFillBitWindowCompileTimeNbits(br, 16, input);
    BrotliTakeBits(br, 16, &mut low_val);
    BrotliFillBitWindowCompileTimeNbits(br, 8, input);
    BrotliTakeBits(br, n_bits - 16, &mut high_val);
    return low_val | (high_val << 16);
  }
}

/* Tries to read the specified amount of bits. Returns 0, if there is not
   enough input. n_bits MUST be positive. */
pub fn BrotliSafeReadBits(
    br : &mut BrotliBitReader, n_bits : u32, val : &mut u32, input : &[u8]) -> bool{
  while BrotliGetAvailableBits(br) < n_bits {
    if !BrotliPullByte(br, input) {
      return false;
    }
  }
  BrotliTakeBits(br, n_bits, val);
  return true;
}

/* Advances the bit reader position to the next byte boundary and verifies
   that any skipped bits are set to zero. */
pub fn BrotliJumpToByteBoundary(br : &mut BrotliBitReader) -> bool {
  let pad_bits_count : u32 = BrotliGetAvailableBits(br) & 0x7;
  let mut pad_bits : u32 = 0;
  if pad_bits_count != 0 {
    BrotliTakeBits(br, pad_bits_count, &mut pad_bits);
  }
  return pad_bits == 0;
}

/* Peeks a byte at specified offset.
   Precondition: bit reader is parked to a byte boundary.
   Returns -1 if operation is not feasible. */
pub fn BrotliPeekByte(br : &mut BrotliBitReader, mut offset : u32, input : &[u8]) -> i32 {
  let available_bits : u32 = BrotliGetAvailableBits(br);
  let bytes_left : u32 = (available_bits >> 3);
  assert!((available_bits & 7) == 0);
  if offset < bytes_left {
    return ((BrotliGetBitsUnmasked(br) >> ((offset << 3)) as u32) & 0xFF) as i32;
  }
  offset -= bytes_left;
  if offset < br.avail_in {
    return input[br.next_in as usize + offset as usize] as i32;
  }
  return -1;
}

/* Copies remaining input bytes stored in the bit reader to the output. Value
   num may not be larger than BrotliGetRemainingBytes. The bit reader must be
   warmed up again after this. */
pub fn BrotliCopyBytes(dest : &mut [u8],
                   br : &mut BrotliBitReader, mut num : u32, input : &[u8]) {
  let mut offset : u32 = 0;
  while BrotliGetAvailableBits(br) >= 8 && num > 0 {
    dest[offset as usize] = BrotliGetBitsUnmasked(br) as u8;
    BrotliDropBits(br, 8);
    offset += 1;
    num -= 1;
  }
  for index in 0..num {
     dest[offset as usize + index as usize] = input[br.next_in as usize + index as usize];
  }
  br.avail_in -= num;
  br.next_in += num;
}

pub fn BrotliInitBitReader(br : &mut BrotliBitReader) {
  br.val_ = 0;
  br.bit_pos_ = (::core::mem::size_of::<reg_t>() << 3) as u32;
}

pub fn BrotliWarmupBitReader(br : &mut BrotliBitReader, input : &[u8]) -> bool{
  let _aligned_read_mask : usize = (::core::mem::size_of::<reg_t>() >> 1) - 1;
  /* Fixing alignment after unaligned BrotliFillWindow would result accumulator
     overflow. If unalignment is caused by BrotliSafeReadBits, then there is
     enough space in accumulator to fix aligment. */
  if BrotliGetAvailableBits(br) == 0 {
    if !BrotliPullByte(br, input) {
      return false;
    }
  }
/* we can't tell about alignment yet
  while (((size_t)br->next_in) & aligned_read_mask) != 0 {
    if !BrotliPullByte(br) {
      /* If we consumed all the input, we don't care about the alignment. */
      return true;
    }
  }
*/
  return true;
}



#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn warmup_works() {
        let data : [u8; 37] = [0xde, 0xad, 0xbe, 0xef, // 4 bytes garbage at beginning
                               0x21, 0xfd, 0xff, 0x87, 0x03, 0x6c, 0x63, 0x90,
                               0xde, 0xe9, 0x36, 0x04, 0xf8, 0x89, 0xb4, 0x4d,
                               0x57, 0x96, 0x51, 0x0a, 0x54, 0xb7, 0x54, 0xee,
                               0xf4, 0xdc, 0xa0, 0x05, 0x9b, 0xd2, 0x2b, 0x30, 0x8f]; // 33 b goods
        let mut bit_reader = BrotliBitReader{val_ : 0x0,
                                         bit_pos_ : 64,
                                         avail_in : 33,
                                         next_in : 4};
        let ret = BrotliWarmupBitReader(&mut bit_reader, &data[..]);
        assert_eq!(ret, true);
        assert_eq!(bit_reader.val_, 0x2100000000000000);
        assert_eq!(bit_reader.bit_pos_, 56);
        assert_eq!(bit_reader.avail_in, 32);
        assert_eq!(bit_reader.next_in, 5);
    }
    #[test]
    fn warmup_errcheck() {
        let data : [u8; 3] = [0xde, 0xad, 0xeb,]; // 3 bytes garbage at beginning
        let mut bit_reader = BrotliBitReader{val_ : 0x86e884e1ffff577b,
                                         bit_pos_ : 64,
                                         avail_in : 0,
                                         next_in : 3};
        let ret = BrotliWarmupBitReader(&mut bit_reader, &data[..]);
        assert_eq!(ret, false);
        assert_eq!(bit_reader.val_, 0x86e884e1ffff577b);
        assert_eq!(bit_reader.bit_pos_, 64);
        assert_eq!(bit_reader.avail_in, 0);
        assert_eq!(bit_reader.next_in, 3);
    }
    #[test]
    fn safe_read_tests() {
        {
           let data : [u8; 12] = [0x50, 0x3b, 0xbb, 0x5e, 0xc5, 0x96, 0x81, 0xb7, 0x52, 0x89, 0xea, 0x3d];
           let mut bit_reader = BrotliBitReader{val_ : 0xe1e56a736e04fbf5,
                                                bit_pos_ : 6,
                                                avail_in : 12,
                                                next_in : 0};
           let mut val : u32 = 0;
           let ret = BrotliSafeReadBits(&mut bit_reader, 7, &mut val, &data[..]);
           assert_eq!(ret, true);
           assert_eq!(val, 0x6f);
           assert_eq!(bit_reader.avail_in, 12);
           assert_eq!(bit_reader.next_in, 0);
           assert_eq!(bit_reader.bit_pos_, 13);
       }
       {
           let data : [u8; 7] = [0xba, 0xd0, 0xf0, 0x0d, 0xc8, 0xcd, 0xcc];
           let mut bit_reader = BrotliBitReader{val_ : 0x17f115ae26916f0,
                                                bit_pos_ : 57,
                                                avail_in : 3,
                                                next_in : 4};
           let mut val : u32 = 0;
           let ret = BrotliSafeReadBits(&mut bit_reader, 15, &mut val, &data[..]);
           assert_eq!(ret, true);
           assert_eq!(val, 0x6400);
           assert_eq!(bit_reader.avail_in, 2);
           assert_eq!(bit_reader.next_in, 5);
           assert_eq!(bit_reader.bit_pos_, 64);
       }
       {
           let data : [u8; 4] = [0xee, 0xee, 0xf0, 0xd5];
           let mut bit_reader = BrotliBitReader{val_ : 0x5f43f252c027e447,
                                                bit_pos_ : 53,
                                                avail_in : 2,
                                                next_in : 2};
           let mut val : u32 = 0;
           let ret = BrotliSafeReadBits(&mut bit_reader, 14, &mut val, &data[..]);
           assert_eq!(ret, true);
           assert_eq!(bit_reader.avail_in, 1);
           assert_eq!(bit_reader.next_in, 3);
           assert_eq!(bit_reader.bit_pos_, 59);
           assert_eq!(bit_reader.val_, 0xf05f43f252c027e4);
           assert_eq!(val, 0x2fa);
       }
       {
           let data : [u8; 4] = [0xee, 0xee, 0xf0, 0xd5];
           let mut bit_reader = BrotliBitReader{val_ : 0x2f902339697460,
                                                bit_pos_ : 57,
                                                avail_in : 0,
                                                next_in : 4};
           let mut val : u32 = 0x74eca3f0;
           let ret = BrotliSafeReadBits(&mut bit_reader, 14, &mut val, &data[..]);
           assert_eq!(ret, false);
           assert_eq!(bit_reader.avail_in, 0);
           assert_eq!(bit_reader.next_in, 4);
           assert_eq!(bit_reader.bit_pos_, 57);
           assert_eq!(bit_reader.val_, 0x2f902339697460);
           assert_eq!(val, 0x74eca3f0);
       }
    }
    #[test]
    fn bit_read_tests() {
        {
            let data : [u8; 32] = [0xba, 0xaa, 0xad, 0xdd, 0x57, 0x5c, 0xd9, 0xa3, 0x3e, 0xb3, 0x77, 0xe7, 0xa0, 0x1e, 0x09, 0xd3, 0x12, 0xa1, 0x3f, 0xb8, 0x7e, 0x5a, 0x06, 0x86, 0xe5, 0x36, 0xef, 0x9c, 0x9f, 0x6d, 0x9b, 0xcc];
            let mut bit_reader = BrotliBitReader{val_ : 0xf5917f07daaaeabb,
                                                bit_pos_ : 33,
                                                avail_in : 29,
                                                next_in : 3};
            let ret = BrotliReadBits(&mut bit_reader, 8, &data[..]);
            assert_eq!(ret, 0x83);
            if super::BROTLI_ALIGNED_READ == 0 {
              assert_eq!(bit_reader.bit_pos_, 41);
              assert_eq!(bit_reader.avail_in, 29);
              assert_eq!(bit_reader.next_in, 3);

            } else {
              assert_eq!(bit_reader.bit_pos_, 9);
              assert_eq!(bit_reader.avail_in, 25);
              assert_eq!(bit_reader.next_in, 7);
            }
        }
        {
            let data : [u8; 28] = [0xba, 0xaa, 0xaa, 0xad, 0x74, 0x40, 0x8e, 0xee, 0xd2, 0x38, 0xf1, 0xf4, 0xf8, 0x1d, 0x9f, 0x24, 0x48, 0x1e, 0x82, 0xce, 0x48, 0x88, 0xd7, 0x25, 0x74, 0xaf, 0xe3, 0xea];
            let mut bit_reader = BrotliBitReader{val_ : 0x27e33b2440d3feaf,
                                                bit_pos_ : 18,
                                                avail_in : 24,
                                                next_in : 4};
            let ret = BrotliReadBits(&mut bit_reader, 15, &data[..]);
            assert_eq!(ret, 0x1034);
            assert_eq!(bit_reader.bit_pos_, 33);
            assert_eq!(bit_reader.avail_in, 24);
            assert_eq!(bit_reader.next_in, 4);
        }
    }
    #[test]
    fn const_fill_bit_window_tests() {
        {
            let data : [u8; 36] = [0xff, 0x9a, 0xa0, 0xde, 0x50, 0x99, 0x67, 0x67, 0x69, 0x87, 0x0e, 0x69, 0xeb, 0x6a, 0xd1, 0x56, 0xc0, 0x32, 0x96, 0xed, 0x78, 0x0e, 0x19, 0xdd, 0x0b, 0xe8, 0xf8, 0x33, 0x9f, 0xe0, 0x69, 0x55, 0x59, 0x3f, 0x5d, 0xc8];
            let mut bit_reader = BrotliBitReader{val_ : 0xb3fc441e0181dc4,
                                                bit_pos_ : 59,
                                                avail_in : 33,
                                                next_in : 1};
            let ret = BrotliReadConstantNBits(&mut bit_reader, 4, &data[..]);
            assert_eq!(ret, 0x1);
            assert_eq!(bit_reader.bit_pos_, 7);
            assert_eq!(bit_reader.avail_in, 26);
            assert_eq!(bit_reader.next_in, 8);
        }
        {
            let data : [u8; 67] = [0xf0, 0x0d, 0x7e, 0x18, 0x70, 0x1c, 0x18, 0x57, 0xbd, 0x73, 0x47, 0xc1, 0xb4, 0xf7, 0xe2, 0xbe, 0x17, 0x6e, 0x26, 0x01, 0xb2, 0xd5, 0x55, 0xd8, 0x68, 0x1b, 0xc2, 0x87, 0xb4, 0xb1, 0xd9, 0x42, 0xac, 0x0d, 0x67, 0xb1, 0x93, 0x54, 0x49, 0xa4, 0x69, 0xf8, 0x16, 0x0e, 0x61, 0xb3, 0xdb, 0x98, 0xbb, 0xeb, 0xfa, 0xcb, 0x14, 0xcd, 0x68, 0x77, 0xa1, 0x33, 0x6c, 0x49, 0xfa, 0x35, 0xbb, 0xeb, 0xee, 0x7b, 0xae];
            let mut bit_reader = BrotliBitReader{val_ : 0x655b1fe0dd6f1e78,
                                                bit_pos_ : 63,
                                                avail_in : 65,
                                                next_in : 2};
            let ret = BrotliGet16BitsUnmasked(&mut bit_reader, &data[..]);
            assert_eq!(ret, 0x38e030fc);
            assert_eq!(bit_reader.bit_pos_, 15);
            assert_eq!(bit_reader.avail_in, 59);
            assert_eq!(bit_reader.next_in, 8);
        }
    }
}