From 0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 03:47:29 +0200 Subject: Adding upstream version 115.8.0esr. Signed-off-by: Daniel Baumann --- modules/brotli/dec/bit_reader.c | 76 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 modules/brotli/dec/bit_reader.c (limited to 'modules/brotli/dec/bit_reader.c') diff --git a/modules/brotli/dec/bit_reader.c b/modules/brotli/dec/bit_reader.c new file mode 100644 index 0000000000..7f7b256a40 --- /dev/null +++ b/modules/brotli/dec/bit_reader.c @@ -0,0 +1,76 @@ +/* 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 */ + +#include "./bit_reader.h" + +#include "../common/platform.h" +#include + +#if defined(__cplusplus) || defined(c_plusplus) +extern "C" { +#endif + +const uint32_t kBrotliBitMask[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 +}; + +void BrotliInitBitReader(BrotliBitReader* const br) { + br->val_ = 0; + br->bit_pos_ = sizeof(br->val_) << 3; +} + +BROTLI_BOOL BrotliWarmupBitReader(BrotliBitReader* const br) { + size_t aligned_read_mask = (sizeof(br->val_) >> 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 alignment. */ + if (!BROTLI_ALIGNED_READ) { + aligned_read_mask = 0; + } + if (BrotliGetAvailableBits(br) == 0) { + if (!BrotliPullByte(br)) { + return BROTLI_FALSE; + } + } + + 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 BROTLI_TRUE; + } + } + return BROTLI_TRUE; +} + +BROTLI_BOOL BrotliSafeReadBits32Slow(BrotliBitReader* const br, + uint32_t n_bits, uint32_t* val) { + uint32_t low_val; + uint32_t high_val; + BrotliBitReaderState memento; + BROTLI_DCHECK(n_bits <= 32); + BROTLI_DCHECK(n_bits > 24); + BrotliBitReaderSaveState(br, &memento); + if (!BrotliSafeReadBits(br, 16, &low_val) || + !BrotliSafeReadBits(br, n_bits - 16, &high_val)) { + BrotliBitReaderRestoreState(br, &memento); + return BROTLI_FALSE; + } + *val = low_val | (high_val << 16); + return BROTLI_TRUE; +} + +#if defined(__cplusplus) || defined(c_plusplus) +} /* extern "C" */ +#endif -- cgit v1.2.3