Add m-esr52 at 52.6.0

1 files changed, 383 insertions, 0 deletions

diff --git a/modules/brotli/dec/bit_reader.h b/modules/brotli/dec/bit_reader.h
new file mode 100644
index 000000000..7096afaa3
--- /dev/null
+++ b/modules/brotli/dec/bit_reader.h
@@ -0,0 +1,383 @@
+/* Copyright 2013 Google Inc. All Rights Reserved.
+
+   Distributed under MIT license.
+   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
+*/
+
+/* Bit reading helpers */
+
+#ifndef BROTLI_DEC_BIT_READER_H_
+#define BROTLI_DEC_BIT_READER_H_
+
+#include <string.h>  /* memcpy */
+
+#include "./port.h"
+#include "./types.h"
+
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
+
+#if (BROTLI_64_BITS)
+#define BROTLI_SHORT_FILL_BIT_WINDOW_READ 4
+typedef uint64_t reg_t;
+#else
+#define BROTLI_SHORT_FILL_BIT_WINDOW_READ 2
+typedef uint32_t reg_t;
+#endif
+
+static const uint32_t kBitMask[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
+};
+
+static BROTLI_INLINE uint32_t BitMask(uint32_t n) {
+  if (IS_CONSTANT(n) || BROTLI_HAS_UBFX) {
+    /* Masking with this expression turns to a single
+       "Unsigned Bit Field Extract" UBFX instruction on ARM. */
+    return ~((0xffffffffU) << n);
+  } else {
+    return kBitMask[n];
+  }
+}
+
+typedef struct {
+  reg_t val_;              /* pre-fetched bits */
+  uint32_t bit_pos_;       /* current bit-reading position in val_ */
+  const uint8_t* next_in;  /* the byte we're reading from */
+  size_t avail_in;
+} BrotliBitReader;
+
+typedef struct {
+  reg_t val_;
+  uint32_t bit_pos_;
+  const uint8_t* next_in;
+  size_t avail_in;
+} BrotliBitReaderState;
+
+/* Initializes the bitreader fields. */
+BROTLI_INTERNAL void BrotliInitBitReader(BrotliBitReader* const br);
+
+/* Ensures that accumulator is not empty. May consume one byte of input.
+   Returns 0 if data is required but there is no input available.
+   For BROTLI_ALIGNED_READ this function also prepares bit reader for aligned
+   reading. */
+BROTLI_INTERNAL int BrotliWarmupBitReader(BrotliBitReader* const br);
+
+static BROTLI_INLINE void BrotliBitReaderSaveState(
+    BrotliBitReader* const from, BrotliBitReaderState* to) {
+  to->val_ = from->val_;
+  to->bit_pos_ = from->bit_pos_;
+  to->next_in = from->next_in;
+  to->avail_in = from->avail_in;
+}
+
+static BROTLI_INLINE void BrotliBitReaderRestoreState(
+    BrotliBitReader* const to, BrotliBitReaderState* from) {
+  to->val_ = from->val_;
+  to->bit_pos_ = from->bit_pos_;
+  to->next_in = from->next_in;
+  to->avail_in = from->avail_in;
+}
+
+static BROTLI_INLINE uint32_t BrotliGetAvailableBits(
+    const BrotliBitReader* br) {
+  return (BROTLI_64_BITS ? 64 : 32) - br->bit_pos_;
+}
+
+/* Returns amount of unread bytes the bit reader still has buffered from the
+   BrotliInput, including whole bytes in br->val_. */
+static BROTLI_INLINE size_t BrotliGetRemainingBytes(BrotliBitReader* br) {
+  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_). */
+static BROTLI_INLINE int BrotliCheckInputAmount(
+    BrotliBitReader* const br, size_t num) {
+  return br->avail_in >= num;
+}
+
+static BROTLI_INLINE uint16_t BrotliLoad16LE(const uint8_t* in) {
+  if (BROTLI_LITTLE_ENDIAN) {
+    return *((const uint16_t*)in);
+  } else if (BROTLI_BIG_ENDIAN) {
+    uint16_t value = *((const uint16_t*)in);
+    return (uint16_t)(((value & 0xFFU) << 8) | ((value & 0xFF00U) >> 8));
+  } else {
+    return (uint16_t)(in[0] | (in[1] << 8));
+  }
+}
+
+static BROTLI_INLINE uint32_t BrotliLoad32LE(const uint8_t* in) {
+  if (BROTLI_LITTLE_ENDIAN) {
+    return *((const uint32_t*)in);
+  } else if (BROTLI_BIG_ENDIAN) {
+    uint32_t value = *((const uint32_t*)in);
+    return ((value & 0xFFU) << 24) | ((value & 0xFF00U) << 8) |
+        ((value & 0xFF0000U) >> 8) | ((value & 0xFF000000U) >> 24);
+  } else {
+    uint32_t value = (uint32_t)(*(in++));
+    value |= (uint32_t)(*(in++)) << 8;
+    value |= (uint32_t)(*(in++)) << 16;
+    value |= (uint32_t)(*(in++)) << 24;
+    return value;
+  }
+}
+
+#if (BROTLI_64_BITS)
+static BROTLI_INLINE uint64_t BrotliLoad64LE(const uint8_t* in) {
+  if (BROTLI_LITTLE_ENDIAN) {
+    return *((const uint64_t*)in);
+  } else if (BROTLI_BIG_ENDIAN) {
+    uint64_t value = *((const uint64_t*)in);
+    return
+        ((value & 0xFFU) << 56) |
+        ((value & 0xFF00U) << 40) |
+        ((value & 0xFF0000U) << 24) |
+        ((value & 0xFF000000U) << 8) |
+        ((value & 0xFF00000000U) >> 8) |
+        ((value & 0xFF0000000000U) >> 24) |
+        ((value & 0xFF000000000000U) >> 40) |
+        ((value & 0xFF00000000000000U) >> 56);
+  } else {
+    uint64_t value = (uint64_t)(*(in++));
+    value |= (uint64_t)(*(in++)) << 8;
+    value |= (uint64_t)(*(in++)) << 16;
+    value |= (uint64_t)(*(in++)) << 24;
+    value |= (uint64_t)(*(in++)) << 32;
+    value |= (uint64_t)(*(in++)) << 40;
+    value |= (uint64_t)(*(in++)) << 48;
+    value |= (uint64_t)(*(in++)) << 56;
+    return value;
+  }
+}
+#endif
+
+/* Guarantees that there are at least n_bits + 1 bits in accumulator.
+   Precondition: accumulator contains at least 1 bit.
+   n_bits should be in the range [1..24] for regular build. For portable
+   non-64-bit little endian build only 16 bits are safe to request. */
+static BROTLI_INLINE void BrotliFillBitWindow(
+    BrotliBitReader* const br, uint32_t n_bits) {
+#if (BROTLI_64_BITS)
+  if (!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(br->next_in) << 8;
+      br->avail_in -= 7;
+      br->next_in += 7;
+    }
+  } else if (!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(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_ |= ((uint64_t)BrotliLoad32LE(br->next_in)) << 32;
+      br->avail_in -= BROTLI_SHORT_FILL_BIT_WINDOW_READ;
+      br->next_in += BROTLI_SHORT_FILL_BIT_WINDOW_READ;
+    }
+  }
+#else
+  if (!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(br->next_in) << 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_ |= ((uint32_t)BrotliLoad16LE(br->next_in)) << 16;
+      br->avail_in -= BROTLI_SHORT_FILL_BIT_WINDOW_READ;
+      br->next_in += BROTLI_SHORT_FILL_BIT_WINDOW_READ;
+    }
+  }
+#endif
+}
+
+/* Mosltly like BrotliFillBitWindow, but guarantees only 16 bits and reads no
+   more than BROTLI_SHORT_FILL_BIT_WINDOW_READ bytes of input. */
+static BROTLI_INLINE void BrotliFillBitWindow16(BrotliBitReader* const br) {
+  BrotliFillBitWindow(br, 17);
+}
+
+/* Pulls one byte of input to accumulator. */
+static BROTLI_INLINE int BrotliPullByte(BrotliBitReader* const br) {
+  if (br->avail_in == 0) {
+    return 0;
+  }
+  br->val_ >>= 8;
+#if (BROTLI_64_BITS)
+  br->val_ |= ((uint64_t)*br->next_in) << 56;
+#else
+  br->val_ |= ((uint32_t)*br->next_in) << 24;
+#endif
+  br->bit_pos_ -= 8;
+  --br->avail_in;
+  ++br->next_in;
+  return 1;
+}
+
+/* Returns currently available bits.
+   The number of valid bits could be calclulated by BrotliGetAvailableBits. */
+static BROTLI_INLINE reg_t BrotliGetBitsUnmasked(BrotliBitReader* const br) {
+  return br->val_ >> br->bit_pos_;
+}
+
+/* Like BrotliGetBits, but does not mask the result.
+   The result contains at least 16 valid bits. */
+static BROTLI_INLINE uint32_t BrotliGet16BitsUnmasked(
+    BrotliBitReader* const br) {
+  BrotliFillBitWindow(br, 16);
+  return (uint32_t)BrotliGetBitsUnmasked(br);
+}
+
+/* Returns the specified number of bits from br without advancing bit pos. */
+static BROTLI_INLINE uint32_t BrotliGetBits(
+    BrotliBitReader* const br, uint32_t n_bits) {
+  BrotliFillBitWindow(br, n_bits);
+  return (uint32_t)BrotliGetBitsUnmasked(br) & BitMask(n_bits);
+}
+
+/* Tries to peek the specified amount of bits. Returns 0, if there is not
+   enough input. */
+static BROTLI_INLINE int BrotliSafeGetBits(
+    BrotliBitReader* const br, uint32_t n_bits, uint32_t* val) {
+  while (BrotliGetAvailableBits(br) < n_bits) {
+    if (!BrotliPullByte(br)) {
+      return 0;
+    }
+  }
+  *val = (uint32_t)BrotliGetBitsUnmasked(br) & BitMask(n_bits);
+  return 1;
+}
+
+/* Advances the bit pos by n_bits. */
+static BROTLI_INLINE void BrotliDropBits(
+    BrotliBitReader* const br, uint32_t n_bits) {
+  br->bit_pos_ += n_bits;
+}
+
+static BROTLI_INLINE void BrotliBitReaderUnload(BrotliBitReader* br) {
+  uint32_t unused_bytes = BrotliGetAvailableBits(br) >> 3;
+  uint32_t unused_bits = unused_bytes << 3;
+  br->avail_in += unused_bytes;
+  br->next_in -= unused_bytes;
+  if (unused_bits == sizeof(br->val_) << 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. */
+static BROTLI_INLINE void BrotliTakeBits(
+  BrotliBitReader* const br, uint32_t n_bits, uint32_t* val) {
+  *val = (uint32_t)BrotliGetBitsUnmasked(br) & BitMask(n_bits);
+  BROTLI_LOG(("[BrotliReadBits]  %d %d %d val: %6x\n",
+      (int)br->avail_in, (int)br->bit_pos_, n_bits, (int)*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. */
+static BROTLI_INLINE uint32_t BrotliReadBits(
+    BrotliBitReader* const br, uint32_t n_bits) {
+  if (BROTLI_64_BITS || (n_bits <= 16)) {
+    uint32_t val;
+    BrotliFillBitWindow(br, n_bits);
+    BrotliTakeBits(br, n_bits, &val);
+    return val;
+  } else {
+    uint32_t low_val;
+    uint32_t high_val;
+    BrotliFillBitWindow(br, 16);
+    BrotliTakeBits(br, 16, &low_val);
+    BrotliFillBitWindow(br, 8);
+    BrotliTakeBits(br, n_bits - 16, &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. */
+static BROTLI_INLINE int BrotliSafeReadBits(
+    BrotliBitReader* const br, uint32_t n_bits, uint32_t* val) {
+  while (BrotliGetAvailableBits(br) < n_bits) {
+    if (!BrotliPullByte(br)) {
+      return 0;
+    }
+  }
+  BrotliTakeBits(br, n_bits, val);
+  return 1;
+}
+
+/* Advances the bit reader position to the next byte boundary and verifies
+   that any skipped bits are set to zero. */
+static BROTLI_INLINE int BrotliJumpToByteBoundary(BrotliBitReader* br) {
+  uint32_t pad_bits_count = BrotliGetAvailableBits(br) & 0x7;
+  uint32_t pad_bits = 0;
+  if (pad_bits_count != 0) {
+    BrotliTakeBits(br, pad_bits_count, &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. */
+static BROTLI_INLINE int BrotliPeekByte(BrotliBitReader* br, size_t offset) {
+  uint32_t available_bits = BrotliGetAvailableBits(br);
+  size_t bytes_left = available_bits >> 3;
+  BROTLI_DCHECK((available_bits & 7) == 0);
+  if (offset < bytes_left) {
+    return (BrotliGetBitsUnmasked(br) >> (unsigned)(offset << 3)) & 0xFF;
+  }
+  offset -= bytes_left;
+  if (offset < br->avail_in) {
+    return br->next_in[offset];
+  }
+  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. */
+static BROTLI_INLINE void BrotliCopyBytes(uint8_t* dest,
+                                          BrotliBitReader* br, size_t num) {
+  while (BrotliGetAvailableBits(br) >= 8 && num > 0) {
+    *dest = (uint8_t)BrotliGetBitsUnmasked(br);
+    BrotliDropBits(br, 8);
+    ++dest;
+    --num;
+  }
+  memcpy(dest, br->next_in, num);
+  br->avail_in -= num;
+  br->next_in += num;
+}
+
+#if defined(__cplusplus) || defined(c_plusplus)
+}  /* extern "C" */
+#endif
+
+#endif  /* BROTLI_DEC_BIT_READER_H_ */