Mercurial > hgrepos > Python2 > PyMuPDF
diff mupdf-source/thirdparty/brotli/c/dec/bit_reader.c @ 2:b50eed0cc0ef upstream
ADD: MuPDF v1.26.7: the MuPDF source as downloaded by a default build of PyMuPDF 1.26.4.
The directory name has changed: no version number in the expanded directory now.
| author | Franz Glasner <fzglas.hg@dom66.de> |
|---|---|
| date | Mon, 15 Sep 2025 11:43:07 +0200 |
| parents | |
| children |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mupdf-source/thirdparty/brotli/c/dec/bit_reader.c Mon Sep 15 11:43:07 2025 +0200 @@ -0,0 +1,78 @@ +/* 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 <brotli/types.h> + +#include "../common/platform.h" + +#if defined(__cplusplus) || defined(c_plusplus) +extern "C" { +#endif + +const brotli_reg_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_ = 0; +} + +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_UNALIGNED_READ_FAST) { + aligned_read_mask = 0; + } + if (BrotliGetAvailableBits(br) == 0) { + br->val_ = 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, + brotli_reg_t n_bits, brotli_reg_t* val) { + brotli_reg_t low_val; + brotli_reg_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
