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author | Anton Samokhvalov <pg83@yandex.ru> | 2022-02-10 16:45:15 +0300 |
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committer | Daniil Cherednik <dcherednik@yandex-team.ru> | 2022-02-10 16:45:15 +0300 |
commit | 72cb13b4aff9bc9cf22e49251bc8fd143f82538f (patch) | |
tree | da2c34829458c7d4e74bdfbdf85dff449e9e7fb8 /contrib/libs/brotli/dec/bit_reader.h | |
parent | 778e51ba091dc39e7b7fcab2b9cf4dbedfb6f2b5 (diff) | |
download | ydb-72cb13b4aff9bc9cf22e49251bc8fd143f82538f.tar.gz |
Restoring authorship annotation for Anton Samokhvalov <pg83@yandex.ru>. Commit 1 of 2.
Diffstat (limited to 'contrib/libs/brotli/dec/bit_reader.h')
-rw-r--r-- | contrib/libs/brotli/dec/bit_reader.h | 232 |
1 files changed, 116 insertions, 116 deletions
diff --git a/contrib/libs/brotli/dec/bit_reader.h b/contrib/libs/brotli/dec/bit_reader.h index c06e91419f..732072bfdd 100644 --- a/contrib/libs/brotli/dec/bit_reader.h +++ b/contrib/libs/brotli/dec/bit_reader.h @@ -1,25 +1,25 @@ -/* Copyright 2013 Google Inc. All Rights Reserved. - +/* 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_ - +*/ + +/* Bit reading helpers */ + +#ifndef BROTLI_DEC_BIT_READER_H_ +#define BROTLI_DEC_BIT_READER_H_ + #include <string.h> /* memcpy */ - + #include "../common/platform.h" #include <brotli/types.h> - -#if defined(__cplusplus) || defined(c_plusplus) -extern "C" { -#endif - + +#if defined(__cplusplus) || defined(c_plusplus) +extern "C" { +#endif + #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, @@ -30,7 +30,7 @@ static const uint32_t kBitMask[33] = { 0x00000000, 0x01FFFFFF, 0x03FFFFFF, 0x07FFFFFF, 0x0FFFFFFF, 0x1FFFFFFF, 0x3FFFFFFF, 0x7FFFFFFF, 0xFFFFFFFF }; - + static BROTLI_INLINE uint32_t BitMask(uint32_t n) { if (BROTLI_IS_CONSTANT(n) || BROTLI_HAS_UBFX) { /* Masking with this expression turns to a single @@ -41,20 +41,20 @@ static BROTLI_INLINE uint32_t BitMask(uint32_t n) { } } -typedef struct { +typedef struct { brotli_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; - +} BrotliBitReader; + typedef struct { brotli_reg_t val_; uint32_t bit_pos_; const uint8_t* next_in; size_t avail_in; } BrotliBitReaderState; - + /* Initializes the BrotliBitReader fields. */ BROTLI_INTERNAL void BrotliInitBitReader(BrotliBitReader* const br); @@ -64,7 +64,7 @@ BROTLI_INTERNAL void BrotliInitBitReader(BrotliBitReader* const br); For BROTLI_ALIGNED_READ this function also prepares bit reader for aligned reading. */ BROTLI_INTERNAL BROTLI_BOOL BrotliWarmupBitReader(BrotliBitReader* const br); - + static BROTLI_INLINE void BrotliBitReaderSaveState( BrotliBitReader* const from, BrotliBitReaderState* to) { to->val_ = from->val_; @@ -72,7 +72,7 @@ static BROTLI_INLINE void BrotliBitReaderSaveState( 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_; @@ -80,15 +80,15 @@ static BROTLI_INLINE void BrotliBitReaderRestoreState( 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) { +} + +/* 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); } @@ -100,59 +100,59 @@ static BROTLI_INLINE BROTLI_BOOL BrotliCheckInputAmount( } /* Guarantees that there are at least |n_bits| + 1 bits in accumulator. - Precondition: accumulator contains at least 1 bit. + 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( +static BROTLI_INLINE void BrotliFillBitWindow( BrotliBitReader* const br, uint32_t n_bits) { #if (BROTLI_64_BITS) if (!BROTLI_ALIGNED_READ && BROTLI_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 */ + if (br->bit_pos_ >= 56) { + br->val_ >>= 56; + br->bit_pos_ ^= 56; /* here same as -= 56 because of the if condition */ br->val_ |= BROTLI_UNALIGNED_LOAD64LE(br->next_in) << 8; - br->avail_in -= 7; - br->next_in += 7; - } + br->avail_in -= 7; + br->next_in += 7; + } } else if ( !BROTLI_ALIGNED_READ && BROTLI_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 */ + if (br->bit_pos_ >= 48) { + br->val_ >>= 48; + br->bit_pos_ ^= 48; /* here same as -= 48 because of the if condition */ br->val_ |= BROTLI_UNALIGNED_LOAD64LE(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->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)BROTLI_UNALIGNED_LOAD32LE(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 && BROTLI_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 */ + if (br->bit_pos_ >= 24) { + br->val_ >>= 24; + br->bit_pos_ ^= 24; /* here same as -= 24 because of the if condition */ br->val_ |= BROTLI_UNALIGNED_LOAD32LE(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->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)BROTLI_UNALIGNED_LOAD16LE(br->next_in)) << 16; br->avail_in -= BROTLI_SHORT_FILL_BIT_WINDOW_READ; br->next_in += BROTLI_SHORT_FILL_BIT_WINDOW_READ; - } - } -#endif -} - + } + } +#endif +} + /* Mostly 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) { @@ -165,25 +165,25 @@ static BROTLI_INLINE BROTLI_BOOL BrotliPullByte(BrotliBitReader* const br) { if (br->avail_in == 0) { return BROTLI_FALSE; } - br->val_ >>= 8; + br->val_ >>= 8; #if (BROTLI_64_BITS) br->val_ |= ((uint64_t)*br->next_in) << 56; -#else +#else br->val_ |= ((uint32_t)*br->next_in) << 24; -#endif - br->bit_pos_ -= 8; - --br->avail_in; - ++br->next_in; +#endif + br->bit_pos_ -= 8; + --br->avail_in; + ++br->next_in; return BROTLI_TRUE; -} - +} + /* Returns currently available bits. The number of valid bits could be calculated by BrotliGetAvailableBits. */ static BROTLI_INLINE brotli_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( @@ -194,12 +194,12 @@ static BROTLI_INLINE uint32_t BrotliGet16BitsUnmasked( /* Returns the specified number of bits from |br| without advancing bit position. */ -static BROTLI_INLINE uint32_t BrotliGetBits( +static BROTLI_INLINE uint32_t BrotliGetBits( BrotliBitReader* const br, uint32_t n_bits) { - BrotliFillBitWindow(br, n_bits); + BrotliFillBitWindow(br, n_bits); return (uint32_t)BrotliGetBitsUnmasked(br) & BitMask(n_bits); -} - +} + /* Tries to peek the specified amount of bits. Returns BROTLI_FALSE, if there is not enough input. */ static BROTLI_INLINE BROTLI_BOOL BrotliSafeGetBits( @@ -214,11 +214,11 @@ static BROTLI_INLINE BROTLI_BOOL BrotliSafeGetBits( } /* Advances the bit pos by |n_bits|. */ -static BROTLI_INLINE void BrotliDropBits( +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; @@ -234,17 +234,17 @@ static BROTLI_INLINE void BrotliBitReaderUnload(BrotliBitReader* br) { /* 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( +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_, (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. */ +static BROTLI_INLINE uint32_t BrotliReadBits( BrotliBitReader* const br, uint32_t n_bits) { if (BROTLI_64_BITS || (n_bits <= 16)) { uint32_t val; @@ -260,8 +260,8 @@ static BROTLI_INLINE uint32_t BrotliReadBits( 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. */ static BROTLI_INLINE BROTLI_BOOL BrotliSafeReadBits( @@ -269,41 +269,41 @@ static BROTLI_INLINE BROTLI_BOOL BrotliSafeReadBits( while (BrotliGetAvailableBits(br) < n_bits) { if (!BrotliPullByte(br)) { return BROTLI_FALSE; - } - } - BrotliTakeBits(br, n_bits, val); + } + } + BrotliTakeBits(br, n_bits, val); return BROTLI_TRUE; -} - -/* Advances the bit reader position to the next byte boundary and verifies - that any skipped bits are set to zero. */ +} + +/* 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) { 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); - } + uint32_t pad_bits = 0; + if (pad_bits_count != 0) { + BrotliTakeBits(br, pad_bits_count, &pad_bits); + } return TO_BROTLI_BOOL(pad_bits == 0); -} - -/* Copies remaining input bytes stored in the bit reader to the output. Value +} + +/* 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) { + 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); + ++dest; + --num; + } + memcpy(dest, br->next_in, num); br->avail_in -= num; - br->next_in += num; -} - -#if defined(__cplusplus) || defined(c_plusplus) + br->next_in += num; +} + +#if defined(__cplusplus) || defined(c_plusplus) } /* extern "C" */ -#endif - -#endif /* BROTLI_DEC_BIT_READER_H_ */ +#endif + +#endif /* BROTLI_DEC_BIT_READER_H_ */ |