diff options
Diffstat (limited to 'c/dec/decode.c')
-rw-r--r-- | c/dec/decode.c | 455 |
1 files changed, 280 insertions, 175 deletions
diff --git a/c/dec/decode.c b/c/dec/decode.c index 846557a..630edeb 100644 --- a/c/dec/decode.c +++ b/c/dec/decode.c @@ -14,15 +14,15 @@ #include <string.h> /* memcpy, memset */ #include "../common/constants.h" +#include "../common/context.h" #include "../common/dictionary.h" #include "../common/platform.h" +#include "../common/transform.h" #include "../common/version.h" #include "./bit_reader.h" -#include "./context.h" #include "./huffman.h" #include "./prefix.h" #include "./state.h" -#include "./transform.h" #if defined(__cplusplus) || defined(c_plusplus) extern "C" { @@ -37,7 +37,7 @@ extern "C" { (unsigned long)(idx), (unsigned long)array_name[idx])) #define HUFFMAN_TABLE_BITS 8U -#define HUFFMAN_TABLE_MASK 0xff +#define HUFFMAN_TABLE_MASK 0xFF /* We need the slack region for the following reasons: - doing up to two 16-byte copies for fast backward copying @@ -59,11 +59,16 @@ static const uint8_t kCodeLengthPrefixValue[16] = { BROTLI_BOOL BrotliDecoderSetParameter( BrotliDecoderState* state, BrotliDecoderParameter p, uint32_t value) { + if (state->state != BROTLI_STATE_UNINITED) return BROTLI_FALSE; switch (p) { case BROTLI_DECODER_PARAM_DISABLE_RING_BUFFER_REALLOCATION: state->canny_ringbuffer_allocation = !!value ? 0 : 1; return BROTLI_TRUE; + case BROTLI_DECODER_PARAM_LARGE_WINDOW: + state->large_window = TO_BROTLI_BOOL(!!value); + return BROTLI_TRUE; + default: return BROTLI_FALSE; } } @@ -80,8 +85,15 @@ BrotliDecoderState* BrotliDecoderCreateInstance( BROTLI_DUMP(); return 0; } - BrotliDecoderStateInitWithCustomAllocators( - state, alloc_func, free_func, opaque); + if (!BrotliDecoderStateInit(state, alloc_func, free_func, opaque)) { + BROTLI_DUMP(); + if (!alloc_func && !free_func) { + free(state); + } else if (alloc_func && free_func) { + free_func(opaque, state); + } + return 0; + } return state; } @@ -97,39 +109,61 @@ void BrotliDecoderDestroyInstance(BrotliDecoderState* state) { } } -/* Saves error code and converts it to BrotliDecoderResult */ +/* Saves error code and converts it to BrotliDecoderResult. */ static BROTLI_NOINLINE BrotliDecoderResult SaveErrorCode( BrotliDecoderState* s, BrotliDecoderErrorCode e) { s->error_code = (int)e; switch (e) { case BROTLI_DECODER_SUCCESS: return BROTLI_DECODER_RESULT_SUCCESS; + case BROTLI_DECODER_NEEDS_MORE_INPUT: return BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT; + case BROTLI_DECODER_NEEDS_MORE_OUTPUT: return BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT; + default: return BROTLI_DECODER_RESULT_ERROR; } } -/* Decodes a number in the range [9..24], by reading 1 - 7 bits. - Precondition: bit-reader accumulator has at least 7 bits. */ -static uint32_t DecodeWindowBits(BrotliBitReader* br) { +/* Decodes WBITS by reading 1 - 7 bits, or 0x11 for "Large Window Brotli". + Precondition: bit-reader accumulator has at least 8 bits. */ +static BrotliDecoderErrorCode DecodeWindowBits(BrotliDecoderState* s, + BrotliBitReader* br) { uint32_t n; + BROTLI_BOOL large_window = s->large_window; + s->large_window = BROTLI_FALSE; BrotliTakeBits(br, 1, &n); if (n == 0) { - return 16; + s->window_bits = 16; + return BROTLI_DECODER_SUCCESS; } BrotliTakeBits(br, 3, &n); if (n != 0) { - return 17 + n; + s->window_bits = 17 + n; + return BROTLI_DECODER_SUCCESS; } BrotliTakeBits(br, 3, &n); + if (n == 1) { + if (large_window) { + BrotliTakeBits(br, 1, &n); + if (n == 1) { + return BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_WINDOW_BITS); + } + s->large_window = BROTLI_TRUE; + return BROTLI_DECODER_SUCCESS; + } else { + return BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_WINDOW_BITS); + } + } if (n != 0) { - return 8 + n; + s->window_bits = 8 + n; + return BROTLI_DECODER_SUCCESS; } - return 17; + s->window_bits = 17; + return BROTLI_DECODER_SUCCESS; } static BROTLI_INLINE void memmove16(uint8_t* dst, uint8_t* src) { @@ -342,7 +376,7 @@ static BROTLI_NOINLINE BROTLI_BOOL SafeDecodeSymbol( *result = table->value; return BROTLI_TRUE; } - return BROTLI_FALSE; /* No valid bits at all. */ + return BROTLI_FALSE; /* No valid bits at all. */ } val = (uint32_t)BrotliGetBitsUnmasked(br); table += val & HUFFMAN_TABLE_MASK; @@ -352,11 +386,11 @@ static BROTLI_NOINLINE BROTLI_BOOL SafeDecodeSymbol( *result = table->value; return BROTLI_TRUE; } else { - return BROTLI_FALSE; /* Not enough bits for the first level. */ + return BROTLI_FALSE; /* Not enough bits for the first level. */ } } if (available_bits <= HUFFMAN_TABLE_BITS) { - return BROTLI_FALSE; /* Not enough bits to move to the second level. */ + return BROTLI_FALSE; /* Not enough bits to move to the second level. */ } /* Speculatively drop HUFFMAN_TABLE_BITS. */ @@ -364,7 +398,7 @@ static BROTLI_NOINLINE BROTLI_BOOL SafeDecodeSymbol( available_bits -= HUFFMAN_TABLE_BITS; table += table->value + val; if (available_bits < table->bits) { - return BROTLI_FALSE; /* Not enough bits for the second level. */ + return BROTLI_FALSE; /* Not enough bits for the second level. */ } BrotliDropBits(br, HUFFMAN_TABLE_BITS + table->bits); @@ -428,12 +462,11 @@ static BROTLI_INLINE uint32_t Log2Floor(uint32_t x) { } /* Reads (s->symbol + 1) symbols. - Totally 1..4 symbols are read, 1..10 bits each. - The list of symbols MUST NOT contain duplicates. - */ + Totally 1..4 symbols are read, 1..11 bits each. + The list of symbols MUST NOT contain duplicates. */ static BrotliDecoderErrorCode ReadSimpleHuffmanSymbols( - uint32_t alphabet_size, BrotliDecoderState* s) { - /* max_bits == 1..10; symbol == 0..3; 1..40 bits will be read. */ + uint32_t alphabet_size, uint32_t max_symbol, BrotliDecoderState* s) { + /* max_bits == 1..11; symbol == 0..3; 1..44 bits will be read. */ BrotliBitReader* br = &s->br; uint32_t max_bits = Log2Floor(alphabet_size - 1); uint32_t i = s->sub_loop_counter; @@ -445,7 +478,7 @@ static BrotliDecoderErrorCode ReadSimpleHuffmanSymbols( s->substate_huffman = BROTLI_STATE_HUFFMAN_SIMPLE_READ; return BROTLI_DECODER_NEEDS_MORE_INPUT; } - if (v >= alphabet_size) { + if (v >= max_symbol) { return BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_SIMPLE_HUFFMAN_ALPHABET); } @@ -471,14 +504,13 @@ static BrotliDecoderErrorCode ReadSimpleHuffmanSymbols( B) remember code length (if it is not 0) C) extend corresponding index-chain D) reduce the Huffman space - E) update the histogram - */ + E) update the histogram */ static BROTLI_INLINE void ProcessSingleCodeLength(uint32_t code_len, uint32_t* symbol, uint32_t* repeat, uint32_t* space, uint32_t* prev_code_len, uint16_t* symbol_lists, uint16_t* code_length_histo, int* next_symbol) { *repeat = 0; - if (code_len != 0) { /* code_len == 1..15 */ + if (code_len != 0) { /* code_len == 1..15 */ symbol_lists[next_symbol[code_len]] = (uint16_t)(*symbol); next_symbol[code_len] = (int)(*symbol); *prev_code_len = code_len; @@ -498,8 +530,7 @@ static BROTLI_INLINE void ProcessSingleCodeLength(uint32_t code_len, D) For each symbol do the same operations as in ProcessSingleCodeLength PRECONDITION: code_len == BROTLI_REPEAT_PREVIOUS_CODE_LENGTH or - code_len == BROTLI_REPEAT_ZERO_CODE_LENGTH - */ + code_len == BROTLI_REPEAT_ZERO_CODE_LENGTH */ static BROTLI_INLINE void ProcessRepeatedCodeLength(uint32_t code_len, uint32_t repeat_delta, uint32_t alphabet_size, uint32_t* symbol, uint32_t* repeat, uint32_t* space, uint32_t* prev_code_len, @@ -576,12 +607,12 @@ static BrotliDecoderErrorCode ReadSymbolCodeLengths( BrotliFillBitWindow16(br); p += BrotliGetBitsUnmasked(br) & BitMask(BROTLI_HUFFMAN_MAX_CODE_LENGTH_CODE_LENGTH); - BrotliDropBits(br, p->bits); /* Use 1..5 bits */ + BrotliDropBits(br, p->bits); /* Use 1..5 bits. */ code_len = p->value; /* code_len == 0..17 */ if (code_len < BROTLI_REPEAT_PREVIOUS_CODE_LENGTH) { ProcessSingleCodeLength(code_len, &symbol, &repeat, &space, &prev_code_len, symbol_lists, code_length_histo, next_symbol); - } else { /* code_len == 16..17, extra_bits == 2..3 */ + } else { /* code_len == 16..17, extra_bits == 2..3 */ uint32_t extra_bits = (code_len == BROTLI_REPEAT_PREVIOUS_CODE_LENGTH) ? 2 : 3; uint32_t repeat_delta = @@ -616,13 +647,13 @@ static BrotliDecoderErrorCode SafeReadSymbolCodeLengths( get_byte = BROTLI_TRUE; continue; } - code_len = p->value; /* code_len == 0..17 */ + code_len = p->value; /* code_len == 0..17 */ if (code_len < BROTLI_REPEAT_PREVIOUS_CODE_LENGTH) { BrotliDropBits(br, p->bits); ProcessSingleCodeLength(code_len, &s->symbol, &s->repeat, &s->space, &s->prev_code_len, s->symbol_lists, s->code_length_histo, s->next_symbol); - } else { /* code_len == 16..17, extra_bits == 2..3 */ + } else { /* code_len == 16..17, extra_bits == 2..3 */ uint32_t extra_bits = code_len - 14U; uint32_t repeat_delta = (bits >> p->bits) & BitMask(extra_bits); if (available_bits < p->bits + extra_bits) { @@ -674,7 +705,7 @@ static BrotliDecoderErrorCode ReadCodeLengthCodeLengths(BrotliDecoderState* s) { ++num_codes; ++s->code_length_histo[v]; if (space - 1U >= 32U) { - /* space is 0 or wrapped around */ + /* space is 0 or wrapped around. */ break; } } @@ -689,22 +720,22 @@ static BrotliDecoderErrorCode ReadCodeLengthCodeLengths(BrotliDecoderState* s) { There are 2 scenarios: A) Huffman code contains only few symbols (1..4). Those symbols are read directly; their code lengths are defined by the number of symbols. - For this scenario 4 - 45 bits will be read. + For this scenario 4 - 49 bits will be read. B) 2-phase decoding: B.1) Small Huffman table is decoded; it is specified with code lengths encoded with predefined entropy code. 32 - 74 bits are used. B.2) Decoded table is used to decode code lengths of symbols in resulting - Huffman table. In worst case 3520 bits are read. -*/ + Huffman table. In worst case 3520 bits are read. */ static BrotliDecoderErrorCode ReadHuffmanCode(uint32_t alphabet_size, + uint32_t max_symbol, HuffmanCode* table, uint32_t* opt_table_size, BrotliDecoderState* s) { BrotliBitReader* br = &s->br; /* Unnecessary masking, but might be good for safety. */ - alphabet_size &= 0x3ff; - /* State machine */ + alphabet_size &= 0x7FF; + /* State machine. */ for (;;) { switch (s->substate_huffman) { case BROTLI_STATE_HUFFMAN_NONE: @@ -717,7 +748,7 @@ static BrotliDecoderErrorCode ReadHuffmanCode(uint32_t alphabet_size, 0 for no skipping, 2 skips 2 code lengths, 3 skips 3 code lengths */ if (s->sub_loop_counter != 1) { s->space = 32; - s->repeat = 0; /* num_codes */ + s->repeat = 0; /* num_codes */ memset(&s->code_length_histo[0], 0, sizeof(s->code_length_histo[0]) * (BROTLI_HUFFMAN_MAX_CODE_LENGTH_CODE_LENGTH + 1)); memset(&s->code_length_code_lengths[0], 0, @@ -729,20 +760,22 @@ static BrotliDecoderErrorCode ReadHuffmanCode(uint32_t alphabet_size, case BROTLI_STATE_HUFFMAN_SIMPLE_SIZE: /* Read symbols, codes & code lengths directly. */ - if (!BrotliSafeReadBits(br, 2, &s->symbol)) { /* num_symbols */ + if (!BrotliSafeReadBits(br, 2, &s->symbol)) { /* num_symbols */ s->substate_huffman = BROTLI_STATE_HUFFMAN_SIMPLE_SIZE; return BROTLI_DECODER_NEEDS_MORE_INPUT; } s->sub_loop_counter = 0; /* No break, transit to the next state. */ + case BROTLI_STATE_HUFFMAN_SIMPLE_READ: { BrotliDecoderErrorCode result = - ReadSimpleHuffmanSymbols(alphabet_size, s); + ReadSimpleHuffmanSymbols(alphabet_size, max_symbol, s); if (result != BROTLI_DECODER_SUCCESS) { return result; } /* No break, transit to the next state. */ } + case BROTLI_STATE_HUFFMAN_SIMPLE_BUILD: { uint32_t table_size; if (s->symbol == 3) { @@ -787,11 +820,12 @@ static BrotliDecoderErrorCode ReadHuffmanCode(uint32_t alphabet_size, s->substate_huffman = BROTLI_STATE_HUFFMAN_LENGTH_SYMBOLS; /* No break, transit to the next state. */ } + case BROTLI_STATE_HUFFMAN_LENGTH_SYMBOLS: { uint32_t table_size; - BrotliDecoderErrorCode result = ReadSymbolCodeLengths(alphabet_size, s); + BrotliDecoderErrorCode result = ReadSymbolCodeLengths(max_symbol, s); if (result == BROTLI_DECODER_NEEDS_MORE_INPUT) { - result = SafeReadSymbolCodeLengths(alphabet_size, s); + result = SafeReadSymbolCodeLengths(max_symbol, s); } if (result != BROTLI_DECODER_SUCCESS) { return result; @@ -823,7 +857,7 @@ static BROTLI_INLINE uint32_t ReadBlockLength(const HuffmanCode* table, uint32_t code; uint32_t nbits; code = ReadSymbol(table, br); - nbits = kBlockLengthPrefixCode[code].nbits; /* nbits == 2..24 */ + nbits = kBlockLengthPrefixCode[code].nbits; /* nbits == 2..24 */ return kBlockLengthPrefixCode[code].offset + BrotliReadBits(br, nbits); } @@ -842,7 +876,7 @@ static BROTLI_INLINE BROTLI_BOOL SafeReadBlockLength( } { uint32_t bits; - uint32_t nbits = kBlockLengthPrefixCode[index].nbits; /* nbits == 2..24 */ + uint32_t nbits = kBlockLengthPrefixCode[index].nbits; /* nbits == 2..24 */ if (!BrotliSafeReadBits(br, nbits, &bits)) { s->block_length_index = index; s->substate_read_block_length = BROTLI_STATE_READ_BLOCK_LENGTH_SUFFIX; @@ -867,8 +901,7 @@ static BROTLI_INLINE BROTLI_BOOL SafeReadBlockLength( of Y values, and reinitialize only first elements in L. Most of input values are 0 and 1. To reduce number of branches, we replace - inner for loop with do-while. - */ + inner for loop with do-while. */ static BROTLI_NOINLINE void InverseMoveToFrontTransform( uint8_t* v, uint32_t v_len, BrotliDecoderState* state) { /* Reinitialize elements that could have been changed. */ @@ -884,7 +917,7 @@ static BROTLI_NOINLINE void InverseMoveToFrontTransform( /* Initialize list using 4 consequent values pattern. */ mtf[0] = pattern; do { - pattern += 0x04040404; /* Advance all 4 values by 4. */ + pattern += 0x04040404; /* Advance all 4 values by 4. */ mtf[i] = pattern; i++; } while (i <= upper_bound); @@ -917,7 +950,8 @@ static BrotliDecoderErrorCode HuffmanTreeGroupDecode( while (s->htree_index < group->num_htrees) { uint32_t table_size; BrotliDecoderErrorCode result = - ReadHuffmanCode(group->alphabet_size, s->next, &table_size, s); + ReadHuffmanCode(group->alphabet_size, group->max_symbol, + s->next, &table_size, s); if (result != BROTLI_DECODER_SUCCESS) return result; group->htrees[s->htree_index] = s->next; s->next += table_size; @@ -934,8 +968,7 @@ static BrotliDecoderErrorCode HuffmanTreeGroupDecode( 2) Decode Huffman table using ReadHuffmanCode function. This table will be used for reading context map items. 3) Read context map items; "0" values could be run-length encoded. - 4) Optionally, apply InverseMoveToFront transform to the resulting map. - */ + 4) Optionally, apply InverseMoveToFront transform to the resulting map. */ static BrotliDecoderErrorCode DecodeContextMap(uint32_t context_map_size, uint32_t* num_htrees, uint8_t** context_map_arg, @@ -964,6 +997,7 @@ static BrotliDecoderErrorCode DecodeContextMap(uint32_t context_map_size, } s->substate_context_map = BROTLI_STATE_CONTEXT_MAP_READ_PREFIX; /* No break, continue to next state. */ + case BROTLI_STATE_CONTEXT_MAP_READ_PREFIX: { uint32_t bits; /* In next stage ReadHuffmanCode uses at least 4 bits, so it is safe @@ -982,13 +1016,17 @@ static BrotliDecoderErrorCode DecodeContextMap(uint32_t context_map_size, s->substate_context_map = BROTLI_STATE_CONTEXT_MAP_HUFFMAN; /* No break, continue to next state. */ } - case BROTLI_STATE_CONTEXT_MAP_HUFFMAN: - result = ReadHuffmanCode(*num_htrees + s->max_run_length_prefix, + + case BROTLI_STATE_CONTEXT_MAP_HUFFMAN: { + uint32_t alphabet_size = *num_htrees + s->max_run_length_prefix; + result = ReadHuffmanCode(alphabet_size, alphabet_size, s->context_map_table, NULL, s); if (result != BROTLI_DECODER_SUCCESS) return result; s->code = 0xFFFF; s->substate_context_map = BROTLI_STATE_CONTEXT_MAP_DECODE; /* No break, continue to next state. */ + } + case BROTLI_STATE_CONTEXT_MAP_DECODE: { uint32_t context_index = s->context_index; uint32_t max_run_length_prefix = s->max_run_length_prefix; @@ -1037,6 +1075,7 @@ static BrotliDecoderErrorCode DecodeContextMap(uint32_t context_map_size, } /* No break, continue to next state. */ } + case BROTLI_STATE_CONTEXT_MAP_TRANSFORM: { uint32_t bits; if (!BrotliSafeReadBits(br, 1, &bits)) { @@ -1049,6 +1088,7 @@ static BrotliDecoderErrorCode DecodeContextMap(uint32_t context_map_size, s->substate_context_map = BROTLI_STATE_CONTEXT_MAP_NONE; return BROTLI_DECODER_SUCCESS; } + default: return BROTLI_FAILURE(BROTLI_DECODER_ERROR_UNREACHABLE); @@ -1067,8 +1107,11 @@ static BROTLI_INLINE BROTLI_BOOL DecodeBlockTypeAndLength( BrotliBitReader* br = &s->br; uint32_t* ringbuffer = &s->block_type_rb[tree_type * 2]; uint32_t block_type; + if (max_block_type <= 1) { + return BROTLI_FALSE; + } - /* Read 0..15 + 3..39 bits */ + /* Read 0..15 + 3..39 bits. */ if (!safe) { block_type = ReadSymbol(type_tree, br); s->block_length[tree_type] = ReadBlockLength(len_tree, br); @@ -1125,9 +1168,8 @@ static BROTLI_INLINE void PrepareLiteralDecoding(BrotliDecoderState* s) { trivial = s->trivial_literal_contexts[block_type >> 5]; s->trivial_literal_context = (trivial >> (block_type & 31)) & 1; s->literal_htree = s->literal_hgroup.htrees[s->context_map_slice[0]]; - context_mode = s->context_modes[block_type]; - s->context_lookup1 = &kContextLookup[kContextLookupOffsets[context_mode]]; - s->context_lookup2 = &kContextLookup[kContextLookupOffsets[context_mode + 1]]; + context_mode = s->context_modes[block_type] & 3; + s->context_lookup = BROTLI_CONTEXT_LUT(context_mode); } /* Decodes the block type and updates the state for literal context. @@ -1164,6 +1206,7 @@ static BROTLI_INLINE BROTLI_BOOL DecodeCommandBlockSwitchInternal( static void BROTLI_NOINLINE DecodeCommandBlockSwitch(BrotliDecoderState* s) { DecodeCommandBlockSwitchInternal(0, s); } + static BROTLI_BOOL BROTLI_NOINLINE SafeDecodeCommandBlockSwitch( BrotliDecoderState* s) { return DecodeCommandBlockSwitchInternal(1, s); @@ -1200,8 +1243,7 @@ static size_t UnwrittenBytes(const BrotliDecoderState* s, BROTLI_BOOL wrap) { /* Dumps output. Returns BROTLI_DECODER_NEEDS_MORE_OUTPUT only if there is more output to push - and either ring-buffer is as big as window size, or |force| is true. - */ + and either ring-buffer is as big as window size, or |force| is true. */ static BrotliDecoderErrorCode BROTLI_NOINLINE WriteRingBuffer( BrotliDecoderState* s, size_t* available_out, uint8_t** next_out, size_t* total_out, BROTLI_BOOL force) { @@ -1260,8 +1302,7 @@ static void BROTLI_NOINLINE WrapRingBuffer(BrotliDecoderState* s) { this function is called. Last two bytes of ring-buffer are initialized to 0, so context calculation - could be done uniformly for the first two and all other positions. -*/ + could be done uniformly for the first two and all other positions. */ static BROTLI_BOOL BROTLI_NOINLINE BrotliEnsureRingBuffer( BrotliDecoderState* s) { uint8_t* old_ringbuffer = s->ringbuffer; @@ -1321,8 +1362,9 @@ static BrotliDecoderErrorCode BROTLI_NOINLINE CopyUncompressedBlockToOutput( return BROTLI_DECODER_NEEDS_MORE_INPUT; } s->substate_uncompressed = BROTLI_STATE_UNCOMPRESSED_WRITE; - /* No break, continue to next state */ + /* No break, continue to next state. */ } + case BROTLI_STATE_UNCOMPRESSED_WRITE: { BrotliDecoderErrorCode result; result = WriteRingBuffer( @@ -1346,8 +1388,7 @@ static BrotliDecoderErrorCode BROTLI_NOINLINE CopyUncompressedBlockToOutput( If we know the data size is small, do not allocate more ring buffer size than needed to reduce memory usage. - When this method is called, metablock size and flags MUST be decoded. -*/ + When this method is called, metablock size and flags MUST be decoded. */ static void BROTLI_NOINLINE BrotliCalculateRingBufferSize( BrotliDecoderState* s) { int window_size = 1 << s->window_bits; @@ -1378,7 +1419,7 @@ static void BROTLI_NOINLINE BrotliCalculateRingBufferSize( if (!!s->canny_ringbuffer_allocation) { /* Reduce ring buffer size to save memory when server is unscrupulous. In worst case memory usage might be 1.5x bigger for a short period of - ring buffer reallocation.*/ + ring buffer reallocation. */ while ((new_ringbuffer_size >> 1) >= min_size) { new_ringbuffer_size >>= 1; } @@ -1398,7 +1439,7 @@ static BrotliDecoderErrorCode ReadContextModes(BrotliDecoderState* s) { s->loop_counter = i; return BROTLI_DECODER_NEEDS_MORE_INPUT; } - s->context_modes[i] = (uint8_t)(bits << 1); + s->context_modes[i] = (uint8_t)bits; BROTLI_LOG_ARRAY_INDEX(s->context_modes, i); i++; } @@ -1413,12 +1454,12 @@ static BROTLI_INLINE void TakeDistanceFromRingBuffer(BrotliDecoderState* s) { s->distance_context = 1; } else { int distance_code = s->distance_code << 1; - /* kDistanceShortCodeIndexOffset has 2-bit values from LSB: */ - /* 3, 2, 1, 0, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2 */ - const uint32_t kDistanceShortCodeIndexOffset = 0xaaafff1b; - /* kDistanceShortCodeValueOffset has 2-bit values from LSB: */ - /*-0, 0,-0, 0,-1, 1,-2, 2,-3, 3,-1, 1,-2, 2,-3, 3 */ - const uint32_t kDistanceShortCodeValueOffset = 0xfa5fa500; + /* kDistanceShortCodeIndexOffset has 2-bit values from LSB: + 3, 2, 1, 0, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2 */ + const uint32_t kDistanceShortCodeIndexOffset = 0xAAAFFF1B; + /* kDistanceShortCodeValueOffset has 2-bit values from LSB: + -0, 0,-0, 0,-1, 1,-2, 2,-3, 3,-1, 1,-2, 2,-3, 3 */ + const uint32_t kDistanceShortCodeValueOffset = 0xFA5FA500; int v = (s->dist_rb_idx + (int)(kDistanceShortCodeIndexOffset >> distance_code)) & 0x3; s->distance_code = s->dist_rb[v]; @@ -1428,9 +1469,9 @@ static BROTLI_INLINE void TakeDistanceFromRingBuffer(BrotliDecoderState* s) { } else { s->distance_code -= v; if (s->distance_code <= 0) { - /* A huge distance will cause a BROTLI_FAILURE() soon. */ - /* This is a little faster than failing here. */ - s->distance_code = 0x0fffffff; + /* A huge distance will cause a BROTLI_FAILURE() soon. + This is a little faster than failing here. */ + s->distance_code = 0x7FFFFFFF; } } } @@ -1446,7 +1487,7 @@ static BROTLI_INLINE BROTLI_BOOL SafeReadBits( } } -/* Precondition: s->distance_code < 0 */ +/* Precondition: s->distance_code < 0. */ static BROTLI_INLINE BROTLI_BOOL ReadDistanceInternal( int safe, BrotliDecoderState* s, BrotliBitReader* br) { int distval; @@ -1462,10 +1503,10 @@ static BROTLI_INLINE BROTLI_BOOL ReadDistanceInternal( } s->distance_code = (int)code; } - /* Convert the distance code to the actual distance by possibly */ - /* looking up past distances from the s->ringbuffer. */ + /* Convert the distance code to the actual distance by possibly + looking up past distances from the s->ringbuffer. */ s->distance_context = 0; - if ((s->distance_code & ~0xf) == 0) { + if ((s->distance_code & ~0xF) == 0) { TakeDistanceFromRingBuffer(s); --s->block_length[2]; return BROTLI_TRUE; @@ -1481,14 +1522,14 @@ static BROTLI_INLINE BROTLI_BOOL ReadDistanceInternal( s->distance_code = (int)s->num_direct_distance_codes + offset + (int)BrotliReadBits(br, nbits); } else { - /* This branch also works well when s->distance_postfix_bits == 0 */ + /* This branch also works well when s->distance_postfix_bits == 0. */ uint32_t bits; postfix = distval & s->distance_postfix_mask; distval >>= s->distance_postfix_bits; nbits = ((uint32_t)distval >> 1) + 1; if (safe) { if (!SafeReadBits(br, nbits, &bits)) { - s->distance_code = -1; /* Restore precondition. */ + s->distance_code = -1; /* Restore precondition. */ BrotliBitReaderRestoreState(br, &memento); return BROTLI_FALSE; } @@ -1615,7 +1656,7 @@ CommandBegin: if (safe) { s->state = BROTLI_STATE_COMMAND_BEGIN; } - if (!CheckInputAmount(safe, br, 28)) { /* 156 bits + 7 bytes */ + if (!CheckInputAmount(safe, br, 28)) { /* 156 bits + 7 bytes */ s->state = BROTLI_STATE_COMMAND_BEGIN; result = BROTLI_DECODER_NEEDS_MORE_INPUT; goto saveStateAndReturn; @@ -1624,7 +1665,7 @@ CommandBegin: BROTLI_SAFE(DecodeCommandBlockSwitch(s)); goto CommandBegin; } - /* Read the insert/copy length in the command */ + /* Read the insert/copy length in the command. */ BROTLI_SAFE(ReadCommand(s, br, &i)); BROTLI_LOG(("[ProcessCommandsInternal] pos = %d insert = %d copy = %d\n", pos, i, s->copy_length)); @@ -1637,13 +1678,13 @@ CommandInner: if (safe) { s->state = BROTLI_STATE_COMMAND_INNER; } - /* Read the literals in the command */ + /* Read the literals in the command. */ if (s->trivial_literal_context) { uint32_t bits; uint32_t value; PreloadSymbol(safe, s->literal_htree, br, &bits, &value); do { - if (!CheckInputAmount(safe, br, 28)) { /* 162 bits + 7 bytes */ + if (!CheckInputAmount(safe, br, 28)) { /* 162 bits + 7 bytes */ s->state = BROTLI_STATE_COMMAND_INNER; result = BROTLI_DECODER_NEEDS_MORE_INPUT; goto saveStateAndReturn; @@ -1679,7 +1720,7 @@ CommandInner: do { const HuffmanCode* hc; uint8_t context; - if (!CheckInputAmount(safe, br, 28)) { /* 162 bits + 7 bytes */ + if (!CheckInputAmount(safe, br, 28)) { /* 162 bits + 7 bytes */ s->state = BROTLI_STATE_COMMAND_INNER; result = BROTLI_DECODER_NEEDS_MORE_INPUT; goto saveStateAndReturn; @@ -1688,7 +1729,7 @@ CommandInner: BROTLI_SAFE(DecodeLiteralBlockSwitch(s)); if (s->trivial_literal_context) goto CommandInner; } - context = s->context_lookup1[p1] | s->context_lookup2[p2]; + context = BROTLI_CONTEXT(p1, p2, s->context_lookup); BROTLI_LOG_UINT(context); hc = s->literal_hgroup.htrees[s->context_map_slice[context]]; p2 = p1; @@ -1744,14 +1785,25 @@ CommandPostDecodeLiterals: } i = s->copy_length; /* Apply copy of LZ77 back-reference, or static dictionary reference if - the distance is larger than the max LZ77 distance */ + the distance is larger than the max LZ77 distance */ if (s->distance_code > s->max_distance) { - int address = s->distance_code - s->max_distance - 1; + /* The maximum allowed distance is BROTLI_MAX_ALLOWED_DISTANCE = 0x7FFFFFFC. + With this choice, no signed overflow can occur after decoding + a special distance code (e.g., after adding 3 to the last distance). */ + if (s->distance_code > BROTLI_MAX_ALLOWED_DISTANCE) { + BROTLI_LOG(("Invalid backward reference. pos: %d distance: %d " + "len: %d bytes left: %d\n", + pos, s->distance_code, i, s->meta_block_remaining_len)); + return BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_DISTANCE); + } if (i >= BROTLI_MIN_DICTIONARY_WORD_LENGTH && i <= BROTLI_MAX_DICTIONARY_WORD_LENGTH) { + int address = s->distance_code - s->max_distance - 1; const BrotliDictionary* words = s->dictionary; + const BrotliTransforms* transforms = s->transforms; int offset = (int)s->dictionary->offsets_by_length[i]; uint32_t shift = s->dictionary->size_bits_by_length[i]; + int mask = (int)BitMask(shift); int word_idx = address & mask; int transform_idx = address >> shift; @@ -1761,16 +1813,16 @@ CommandPostDecodeLiterals: if (BROTLI_PREDICT_FALSE(!words->data)) { return BROTLI_FAILURE(BROTLI_DECODER_ERROR_DICTIONARY_NOT_SET); } - if (transform_idx < kNumTransforms) { + if (transform_idx < (int)transforms->num_transforms) { const uint8_t* word = &words->data[offset]; int len = i; - if (transform_idx == 0) { + if (transform_idx == transforms->cutOffTransforms[0]) { memcpy(&s->ringbuffer[pos], word, (size_t)len); BROTLI_LOG(("[ProcessCommandsInternal] dictionary word: [%.*s]\n", len, word)); } else { len = BrotliTransformDictionaryWord(&s->ringbuffer[pos], word, len, - transform_idx); + transforms, transform_idx); BROTLI_LOG(("[ProcessCommandsInternal] dictionary word: [%.*s]," " transform_idx = %d, transformed: [%.*s]\n", i, word, transform_idx, len, &s->ringbuffer[pos])); @@ -1778,7 +1830,6 @@ CommandPostDecodeLiterals: pos += len; s->meta_block_remaining_len -= len; if (pos >= s->ringbuffer_size) { - /*s->partial_pos_rb += (size_t)s->ringbuffer_size;*/ s->state = BROTLI_STATE_COMMAND_POST_WRITE_1; goto saveStateAndReturn; } @@ -1800,14 +1851,13 @@ CommandPostDecodeLiterals: uint8_t* copy_src = &s->ringbuffer[src_start]; int dst_end = pos + i; int src_end = src_start + i; - /* update the recent distances cache */ + /* Update the recent distances cache. */ s->dist_rb[s->dist_rb_idx & 3] = s->distance_code; ++s->dist_rb_idx; s->meta_block_remaining_len -= i; /* There are 32+ bytes of slack in the ring-buffer allocation. Also, we have 16 short codes, that make these 16 bytes irrelevant - in the ring-buffer. Let's copy over them as a first guess. - */ + in the ring-buffer. Let's copy over them as a first guess. */ memmove16(copy_dst, copy_src); if (src_end > pos && dst_end > src_start) { /* Regions intersect. */ @@ -1830,7 +1880,7 @@ CommandPostDecodeLiterals: } BROTLI_LOG_UINT(s->meta_block_remaining_len); if (s->meta_block_remaining_len <= 0) { - /* Next metablock, if any */ + /* Next metablock, if any. */ s->state = BROTLI_STATE_METABLOCK_DONE; goto saveStateAndReturn; } else { @@ -1850,7 +1900,7 @@ CommandPostWrapCopy: } } if (s->meta_block_remaining_len <= 0) { - /* Next metablock, if any */ + /* Next metablock, if any. */ s->state = BROTLI_STATE_METABLOCK_DONE; goto saveStateAndReturn; } else { @@ -1875,6 +1925,21 @@ static BROTLI_NOINLINE BrotliDecoderErrorCode SafeProcessCommands( return ProcessCommandsInternal(1, s); } +/* Returns the maximum number of distance symbols which can only represent + distances not exceeding BROTLI_MAX_ALLOWED_DISTANCE. */ +static uint32_t BrotliMaxDistanceSymbol(uint32_t ndirect, uint32_t npostfix) { + static const uint32_t bound[BROTLI_MAX_NPOSTFIX + 1] = {0, 4, 12, 28}; + static const uint32_t diff[BROTLI_MAX_NPOSTFIX + 1] = {73, 126, 228, 424}; + uint32_t postfix = 1U << npostfix; + if (ndirect < bound[npostfix]) { + return ndirect + diff[npostfix] + postfix; + } else if (ndirect > bound[npostfix] + postfix) { + return ndirect + diff[npostfix]; + } else { + return bound[npostfix] + diff[npostfix] + postfix; + } +} + BrotliDecoderResult BrotliDecoderDecompress( size_t encoded_size, const uint8_t* encoded_buffer, size_t* decoded_size, uint8_t* decoded_buffer) { @@ -1885,7 +1950,9 @@ BrotliDecoderResult BrotliDecoderDecompress( const uint8_t* next_in = encoded_buffer; size_t available_out = *decoded_size; uint8_t* next_out = decoded_buffer; - BrotliDecoderStateInit(&s); + if (!BrotliDecoderStateInit(&s, 0, 0, 0)) { + return BROTLI_DECODER_RESULT_ERROR; + } result = BrotliDecoderDecompressStream( &s, &available_in, &next_in, &available_out, &next_out, &total_out); *decoded_size = total_out; @@ -1897,23 +1964,22 @@ BrotliDecoderResult BrotliDecoderDecompress( } /* Invariant: input stream is never overconsumed: - * invalid input implies that the whole stream is invalid -> any amount of + - invalid input implies that the whole stream is invalid -> any amount of input could be read and discarded - * when result is "needs more input", then at least one more byte is REQUIRED + - when result is "needs more input", then at least one more byte is REQUIRED to complete decoding; all input data MUST be consumed by decoder, so client could swap the input buffer - * when result is "needs more output" decoder MUST ensure that it doesn't + - when result is "needs more output" decoder MUST ensure that it doesn't hold more than 7 bits in bit reader; this saves client from swapping input buffer ahead of time - * when result is "success" decoder MUST return all unused data back to input - buffer; this is possible because the invariant is hold on enter -*/ + - when result is "success" decoder MUST return all unused data back to input + buffer; this is possible because the invariant is held on enter */ BrotliDecoderResult BrotliDecoderDecompressStream( BrotliDecoderState* s, size_t* available_in, const uint8_t** next_in, size_t* available_out, uint8_t** next_out, size_t* total_out) { BrotliDecoderErrorCode result = BROTLI_DECODER_SUCCESS; BrotliBitReader* br = &s->br; - /* Ensure that *total_out is set, even if no data will ever be pushed out. */ + /* Ensure that |total_out| is set, even if no data will ever be pushed out. */ if (total_out) { *total_out = s->partial_pos_out; } @@ -1926,7 +1992,7 @@ BrotliDecoderResult BrotliDecoderDecompressStream( s, BROTLI_FAILURE(BROTLI_DECODER_ERROR_INVALID_ARGUMENTS)); } if (!*available_out) next_out = 0; - if (s->buffer_length == 0) { /* Just connect bit reader to input stream. */ + if (s->buffer_length == 0) { /* Just connect bit reader to input stream. */ br->avail_in = *available_in; br->next_in = *next_in; } else { @@ -1938,9 +2004,10 @@ BrotliDecoderResult BrotliDecoderDecompressStream( } /* State machine */ for (;;) { - if (result != BROTLI_DECODER_SUCCESS) { /* Error, needs more input/output */ + if (result != BROTLI_DECODER_SUCCESS) { + /* Error, needs more input/output. */ if (result == BROTLI_DECODER_NEEDS_MORE_INPUT) { - if (s->ringbuffer != 0) { /* Pro-actively push output. */ + if (s->ringbuffer != 0) { /* Pro-actively push output. */ BrotliDecoderErrorCode intermediate_result = WriteRingBuffer(s, available_out, next_out, total_out, BROTLI_TRUE); /* WriteRingBuffer checks s->meta_block_remaining_len validity. */ @@ -1949,9 +2016,10 @@ BrotliDecoderResult BrotliDecoderDecompressStream( break; } } - if (s->buffer_length != 0) { /* Used with internal buffer. */ - if (br->avail_in == 0) { /* Successfully finished read transaction. */ - /* Accumulator contains less than 8 bits, because internal buffer + if (s->buffer_length != 0) { /* Used with internal buffer. */ + if (br->avail_in == 0) { + /* Successfully finished read transaction. + Accumulator contains less than 8 bits, because internal buffer is expanded byte-by-byte until it is enough to complete read. */ s->buffer_length = 0; /* Switch to input stream and restart. */ @@ -1971,9 +2039,9 @@ BrotliDecoderResult BrotliDecoderDecompressStream( /* Retry with more data in buffer. */ continue; } - /* Can't finish reading and no more input.*/ + /* Can't finish reading and no more input. */ break; - } else { /* Input stream doesn't contain enough input. */ + } else { /* Input stream doesn't contain enough input. */ /* Copy tail to internal buffer and return. */ *next_in = br->next_in; *available_in = br->avail_in; @@ -1992,7 +2060,7 @@ BrotliDecoderResult BrotliDecoderDecompressStream( if (s->buffer_length != 0) { /* Just consumed the buffered input and produced some output. Otherwise - it would result in "needs more input". Reset internal buffer.*/ + it would result in "needs more input". Reset internal buffer. */ s->buffer_length = 0; } else { /* Using input stream in last iteration. When decoder switches to input @@ -2012,13 +2080,32 @@ BrotliDecoderResult BrotliDecoderDecompressStream( break; } /* Decode window size. */ - s->window_bits = DecodeWindowBits(br); /* Reads 1..7 bits. */ - BROTLI_LOG_UINT(s->window_bits); - if (s->window_bits == 9) { - /* Value 9 is reserved for future use. */ + result = DecodeWindowBits(s, br); /* Reads 1..8 bits. */ + if (result != BROTLI_DECODER_SUCCESS) { + break; + } + if (s->large_window) { + s->state = BROTLI_STATE_LARGE_WINDOW_BITS; + break; + } + s->state = BROTLI_STATE_INITIALIZE; + break; + + case BROTLI_STATE_LARGE_WINDOW_BITS: + if (!BrotliSafeReadBits(br, 6, &s->window_bits)) { + result = BROTLI_DECODER_NEEDS_MORE_INPUT; + break; + } + if (s->window_bits < BROTLI_LARGE_MIN_WBITS || + s->window_bits > BROTLI_LARGE_MAX_WBITS) { result = BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_WINDOW_BITS); break; } + s->state = BROTLI_STATE_INITIALIZE; + /* No break, continue to next state */ + + case BROTLI_STATE_INITIALIZE: + BROTLI_LOG_UINT(s->window_bits); /* Maximum distance, see section 9.1. of the spec. */ s->max_backward_distance = (1 << s->window_bits) - BROTLI_WINDOW_GAP; @@ -2034,14 +2121,16 @@ BrotliDecoderResult BrotliDecoderDecompressStream( s->block_type_trees + 3 * BROTLI_HUFFMAN_MAX_SIZE_258; s->state = BROTLI_STATE_METABLOCK_BEGIN; - /* No break, continue to next state */ + /* No break, continue to next state. */ + case BROTLI_STATE_METABLOCK_BEGIN: BrotliDecoderStateMetablockBegin(s); BROTLI_LOG_UINT(s->pos); s->state = BROTLI_STATE_METABLOCK_HEADER; - /* No break, continue to next state */ + /* No break, continue to next state. */ + case BROTLI_STATE_METABLOCK_HEADER: - result = DecodeMetaBlockLength(s, br); /* Reads 2 - 31 bits. */ + result = DecodeMetaBlockLength(s, br); /* Reads 2 - 31 bits. */ if (result != BROTLI_DECODER_SUCCESS) { break; } @@ -2071,6 +2160,7 @@ BrotliDecoderResult BrotliDecoderDecompressStream( s->loop_counter = 0; s->state = BROTLI_STATE_HUFFMAN_CODE_0; break; + case BROTLI_STATE_UNCOMPRESSED: { result = CopyUncompressedBlockToOutput( available_out, next_out, total_out, s); @@ -2080,6 +2170,7 @@ BrotliDecoderResult BrotliDecoderDecompressStream( s->state = BROTLI_STATE_METABLOCK_DONE; break; } + case BROTLI_STATE_METADATA: for (; s->meta_block_remaining_len > 0; --s->meta_block_remaining_len) { uint32_t bits; @@ -2093,6 +2184,7 @@ BrotliDecoderResult BrotliDecoderDecompressStream( s->state = BROTLI_STATE_METABLOCK_DONE; } break; + case BROTLI_STATE_HUFFMAN_CODE_0: if (s->loop_counter >= 3) { s->state = BROTLI_STATE_METABLOCK_HEADER_2; @@ -2110,23 +2202,28 @@ BrotliDecoderResult BrotliDecoderDecompressStream( break; } s->state = BROTLI_STATE_HUFFMAN_CODE_1; - /* No break, continue to next state */ + /* No break, continue to next state. */ + case BROTLI_STATE_HUFFMAN_CODE_1: { + uint32_t alphabet_size = s->num_block_types[s->loop_counter] + 2; int tree_offset = s->loop_counter * BROTLI_HUFFMAN_MAX_SIZE_258; - result = ReadHuffmanCode(s->num_block_types[s->loop_counter] + 2, + result = ReadHuffmanCode(alphabet_size, alphabet_size, &s->block_type_trees[tree_offset], NULL, s); if (result != BROTLI_DECODER_SUCCESS) break; s->state = BROTLI_STATE_HUFFMAN_CODE_2; - /* No break, continue to next state */ + /* No break, continue to next state. */ } + case BROTLI_STATE_HUFFMAN_CODE_2: { + uint32_t alphabet_size = BROTLI_NUM_BLOCK_LEN_SYMBOLS; int tree_offset = s->loop_counter * BROTLI_HUFFMAN_MAX_SIZE_26; - result = ReadHuffmanCode(BROTLI_NUM_BLOCK_LEN_SYMBOLS, + result = ReadHuffmanCode(alphabet_size, alphabet_size, &s->block_len_trees[tree_offset], NULL, s); if (result != BROTLI_DECODER_SUCCESS) break; s->state = BROTLI_STATE_HUFFMAN_CODE_3; - /* No break, continue to next state */ + /* No break, continue to next state. */ } + case BROTLI_STATE_HUFFMAN_CODE_3: { int tree_offset = s->loop_counter * BROTLI_HUFFMAN_MAX_SIZE_26; if (!SafeReadBlockLength(s, &s->block_length[s->loop_counter], @@ -2139,6 +2236,7 @@ BrotliDecoderResult BrotliDecoderDecompressStream( s->state = BROTLI_STATE_HUFFMAN_CODE_0; break; } + case BROTLI_STATE_METABLOCK_HEADER_2: { uint32_t bits; if (!BrotliSafeReadBits(br, 6, &bits)) { @@ -2160,15 +2258,17 @@ BrotliDecoderResult BrotliDecoderDecompressStream( } s->loop_counter = 0; s->state = BROTLI_STATE_CONTEXT_MODES; - /* No break, continue to next state */ + /* No break, continue to next state. */ } + case BROTLI_STATE_CONTEXT_MODES: result = ReadContextModes(s); if (result != BROTLI_DECODER_SUCCESS) { break; } s->state = BROTLI_STATE_CONTEXT_MAP_1; - /* No break, continue to next state */ + /* No break, continue to next state. */ + case BROTLI_STATE_CONTEXT_MAP_1: result = DecodeContextMap( s->num_block_types[0] << BROTLI_LITERAL_CONTEXT_BITS, @@ -2178,54 +2278,54 @@ BrotliDecoderResult BrotliDecoderDecompressStream( } DetectTrivialLiteralBlockTypes(s); s->state = BROTLI_STATE_CONTEXT_MAP_2; - /* No break, continue to next state */ - case BROTLI_STATE_CONTEXT_MAP_2: - { - uint32_t num_distance_codes = s->num_direct_distance_codes + - ((2 * BROTLI_MAX_DISTANCE_BITS) << s->distance_postfix_bits); - BROTLI_BOOL allocation_success = BROTLI_TRUE; - result = DecodeContextMap( - s->num_block_types[2] << BROTLI_DISTANCE_CONTEXT_BITS, - &s->num_dist_htrees, &s->dist_context_map, s); - if (result != BROTLI_DECODER_SUCCESS) { - break; - } - allocation_success &= BrotliDecoderHuffmanTreeGroupInit( - s, &s->literal_hgroup, BROTLI_NUM_LITERAL_SYMBOLS, - s->num_literal_htrees); - allocation_success &= BrotliDecoderHuffmanTreeGroupInit( - s, &s->insert_copy_hgroup, BROTLI_NUM_COMMAND_SYMBOLS, - s->num_block_types[1]); - allocation_success &= BrotliDecoderHuffmanTreeGroupInit( - s, &s->distance_hgroup, num_distance_codes, - s->num_dist_htrees); - if (!allocation_success) { - return SaveErrorCode(s, - BROTLI_FAILURE(BROTLI_DECODER_ERROR_ALLOC_TREE_GROUPS)); - } + /* No break, continue to next state. */ + + case BROTLI_STATE_CONTEXT_MAP_2: { + uint32_t num_direct_codes = + s->num_direct_distance_codes - BROTLI_NUM_DISTANCE_SHORT_CODES; + uint32_t num_distance_codes = BROTLI_DISTANCE_ALPHABET_SIZE( + num_direct_codes, s->distance_postfix_bits, + (s->large_window ? BROTLI_LARGE_MAX_DISTANCE_BITS : + BROTLI_MAX_DISTANCE_BITS)); + uint32_t max_distance_symbol = (s->large_window ? + BrotliMaxDistanceSymbol( + num_direct_codes, s->distance_postfix_bits) : + num_distance_codes); + BROTLI_BOOL allocation_success = BROTLI_TRUE; + result = DecodeContextMap( + s->num_block_types[2] << BROTLI_DISTANCE_CONTEXT_BITS, + &s->num_dist_htrees, &s->dist_context_map, s); + if (result != BROTLI_DECODER_SUCCESS) { + break; + } + allocation_success &= BrotliDecoderHuffmanTreeGroupInit( + s, &s->literal_hgroup, BROTLI_NUM_LITERAL_SYMBOLS, + BROTLI_NUM_LITERAL_SYMBOLS, s->num_literal_htrees); + allocation_success &= BrotliDecoderHuffmanTreeGroupInit( + s, &s->insert_copy_hgroup, BROTLI_NUM_COMMAND_SYMBOLS, + BROTLI_NUM_COMMAND_SYMBOLS, s->num_block_types[1]); + allocation_success &= BrotliDecoderHuffmanTreeGroupInit( + s, &s->distance_hgroup, num_distance_codes, + max_distance_symbol, s->num_dist_htrees); + if (!allocation_success) { + return SaveErrorCode(s, + BROTLI_FAILURE(BROTLI_DECODER_ERROR_ALLOC_TREE_GROUPS)); } s->loop_counter = 0; s->state = BROTLI_STATE_TREE_GROUP; - /* No break, continue to next state */ - case BROTLI_STATE_TREE_GROUP: - { - HuffmanTreeGroup* hgroup = NULL; - switch (s->loop_counter) { - case 0: - hgroup = &s->literal_hgroup; - break; - case 1: - hgroup = &s->insert_copy_hgroup; - break; - case 2: - hgroup = &s->distance_hgroup; - break; - default: - return SaveErrorCode(s, BROTLI_FAILURE( - BROTLI_DECODER_ERROR_UNREACHABLE)); - } - result = HuffmanTreeGroupDecode(hgroup, s); + /* No break, continue to next state. */ + } + + case BROTLI_STATE_TREE_GROUP: { + HuffmanTreeGroup* hgroup = NULL; + switch (s->loop_counter) { + case 0: hgroup = &s->literal_hgroup; break; + case 1: hgroup = &s->insert_copy_hgroup; break; + case 2: hgroup = &s->distance_hgroup; break; + default: return SaveErrorCode(s, BROTLI_FAILURE( + BROTLI_DECODER_ERROR_UNREACHABLE)); } + result = HuffmanTreeGroupDecode(hgroup, s); if (result != BROTLI_DECODER_SUCCESS) break; s->loop_counter++; if (s->loop_counter >= 3) { @@ -2239,6 +2339,8 @@ BrotliDecoderResult BrotliDecoderDecompressStream( s->state = BROTLI_STATE_COMMAND_BEGIN; } break; + } + case BROTLI_STATE_COMMAND_BEGIN: case BROTLI_STATE_COMMAND_INNER: case BROTLI_STATE_COMMAND_POST_DECODE_LITERALS: @@ -2248,6 +2350,7 @@ BrotliDecoderResult BrotliDecoderDecompressStream( result = SafeProcessCommands(s); } break; + case BROTLI_STATE_COMMAND_INNER_WRITE: case BROTLI_STATE_COMMAND_POST_WRITE_1: case BROTLI_STATE_COMMAND_POST_WRITE_2: @@ -2262,7 +2365,7 @@ BrotliDecoderResult BrotliDecoderDecompressStream( } if (s->state == BROTLI_STATE_COMMAND_POST_WRITE_1) { if (s->meta_block_remaining_len == 0) { - /* Next metablock, if any */ + /* Next metablock, if any. */ s->state = BROTLI_STATE_METABLOCK_DONE; } else { s->state = BROTLI_STATE_COMMAND_BEGIN; @@ -2282,6 +2385,7 @@ BrotliDecoderResult BrotliDecoderDecompressStream( s->state = BROTLI_STATE_COMMAND_INNER; } break; + case BROTLI_STATE_METABLOCK_DONE: if (s->meta_block_remaining_len < 0) { result = BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_BLOCK_LENGTH_2); @@ -2302,7 +2406,8 @@ BrotliDecoderResult BrotliDecoderDecompressStream( *next_in = br->next_in; } s->state = BROTLI_STATE_DONE; - /* No break, continue to next state */ + /* No break, continue to next state. */ + case BROTLI_STATE_DONE: if (s->ringbuffer != 0) { result = WriteRingBuffer( |