From b645d59b1e170af1cb0963935bd8c915e56c431c Mon Sep 17 00:00:00 2001 From: Moonchild Date: Fri, 13 Nov 2020 15:59:29 +0000 Subject: Issue #1683 - Update Brotli lib to 1.0.9 --- modules/brotli/dec/bit_reader.h | 74 ++++++++++++++++++++++++++++++++--------- 1 file changed, 58 insertions(+), 16 deletions(-) (limited to 'modules/brotli/dec/bit_reader.h') diff --git a/modules/brotli/dec/bit_reader.h b/modules/brotli/dec/bit_reader.h index c06e91419..22bc060ca 100644 --- a/modules/brotli/dec/bit_reader.h +++ b/modules/brotli/dec/bit_reader.h @@ -11,6 +11,7 @@ #include /* memcpy */ +#include "../common/constants.h" #include "../common/platform.h" #include @@ -20,16 +21,7 @@ extern "C" { #define BROTLI_SHORT_FILL_BIT_WINDOW_READ (sizeof(brotli_reg_t) >> 1) -static const uint32_t kBitMask[33] = { 0x00000000, - 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 -}; +BROTLI_INTERNAL extern const uint32_t kBrotliBitMask[33]; static BROTLI_INLINE uint32_t BitMask(uint32_t n) { if (BROTLI_IS_CONSTANT(n) || BROTLI_HAS_UBFX) { @@ -37,7 +29,7 @@ static BROTLI_INLINE uint32_t BitMask(uint32_t n) { "Unsigned Bit Field Extract" UBFX instruction on ARM. */ return ~((0xFFFFFFFFu) << n); } else { - return kBitMask[n]; + return kBrotliBitMask[n]; } } @@ -65,6 +57,12 @@ BROTLI_INTERNAL void BrotliInitBitReader(BrotliBitReader* const br); reading. */ BROTLI_INTERNAL BROTLI_BOOL BrotliWarmupBitReader(BrotliBitReader* const br); +/* Fallback for BrotliSafeReadBits32. Extracted as noninlined method to unburden + the main code-path. Never called for RFC brotli streams, required only for + "large-window" mode and other extensions. */ +BROTLI_INTERNAL BROTLI_NOINLINE BROTLI_BOOL BrotliSafeReadBits32Slow( + BrotliBitReader* const br, uint32_t n_bits, uint32_t* val); + static BROTLI_INLINE void BrotliBitReaderSaveState( BrotliBitReader* const from, BrotliBitReaderState* to) { to->val_ = from->val_; @@ -87,8 +85,11 @@ static BROTLI_INLINE uint32_t BrotliGetAvailableBits( } /* Returns amount of unread bytes the bit reader still has buffered from the - BrotliInput, including whole bytes in br->val_. */ + BrotliInput, including whole bytes in br->val_. Result is capped with + maximal ring-buffer size (larger number won't be utilized anyway). */ static BROTLI_INLINE size_t BrotliGetRemainingBytes(BrotliBitReader* br) { + static const size_t kCap = (size_t)1 << BROTLI_LARGE_MAX_WBITS; + if (br->avail_in > kCap) return kCap; return br->avail_in + (BrotliGetAvailableBits(br) >> 3); } @@ -237,15 +238,17 @@ static BROTLI_INLINE void BrotliBitReaderUnload(BrotliBitReader* br) { 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", + BROTLI_LOG(("[BrotliTakeBits] %d %d %d val: %6x\n", (int)br->avail_in, (int)br->bit_pos_, (int)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( + Assumes that there is enough input to perform BrotliFillBitWindow. + Up to 24 bits are allowed to be requested from this method. */ +static BROTLI_INLINE uint32_t BrotliReadBits24( BrotliBitReader* const br, uint32_t n_bits) { + BROTLI_DCHECK(n_bits <= 24); if (BROTLI_64_BITS || (n_bits <= 16)) { uint32_t val; BrotliFillBitWindow(br, n_bits); @@ -262,10 +265,32 @@ static BROTLI_INLINE uint32_t BrotliReadBits( } } +/* Same as BrotliReadBits24, but allows reading up to 32 bits. */ +static BROTLI_INLINE uint32_t BrotliReadBits32( + BrotliBitReader* const br, uint32_t n_bits) { + BROTLI_DCHECK(n_bits <= 32); + 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, 16); + BrotliTakeBits(br, n_bits - 16, &high_val); + return low_val | (high_val << 16); + } +} + /* Tries to read the specified amount of bits. Returns BROTLI_FALSE, if there - is not enough input. |n_bits| MUST be positive. */ + is not enough input. |n_bits| MUST be positive. + Up to 24 bits are allowed to be requested from this method. */ static BROTLI_INLINE BROTLI_BOOL BrotliSafeReadBits( BrotliBitReader* const br, uint32_t n_bits, uint32_t* val) { + BROTLI_DCHECK(n_bits <= 24); while (BrotliGetAvailableBits(br) < n_bits) { if (!BrotliPullByte(br)) { return BROTLI_FALSE; @@ -275,6 +300,23 @@ static BROTLI_INLINE BROTLI_BOOL BrotliSafeReadBits( return BROTLI_TRUE; } +/* Same as BrotliSafeReadBits, but allows reading up to 32 bits. */ +static BROTLI_INLINE BROTLI_BOOL BrotliSafeReadBits32( + BrotliBitReader* const br, uint32_t n_bits, uint32_t* val) { + BROTLI_DCHECK(n_bits <= 32); + if (BROTLI_64_BITS || (n_bits <= 24)) { + while (BrotliGetAvailableBits(br) < n_bits) { + if (!BrotliPullByte(br)) { + return BROTLI_FALSE; + } + } + BrotliTakeBits(br, n_bits, val); + return BROTLI_TRUE; + } else { + return BrotliSafeReadBits32Slow(br, n_bits, val); + } +} + /* Advances the bit reader position to the next byte boundary and verifies that any skipped bits are set to zero. */ static BROTLI_INLINE BROTLI_BOOL BrotliJumpToByteBoundary(BrotliBitReader* br) { -- cgit v1.2.3