--- /dev/null
+/* Copyright 2013 Google Inc. All Rights Reserved.\r
+\r
+ Distributed under MIT license.\r
+ See file LICENSE for detail or copy at https://opensource.org/licenses/MIT\r
+*/\r
+\r
+#include "./decode.h"\r
+\r
+#ifdef __ARM_NEON__\r
+#include <arm_neon.h>\r
+#endif\r
+\r
+#include <stdlib.h> /* free, malloc */\r
+#include <string.h> /* memcpy, memset */\r
+\r
+#include "../common/constants.h"\r
+#include "../common/dictionary.h"\r
+#include "./bit_reader.h"\r
+#include "./context.h"\r
+#include "./huffman.h"\r
+#include "./port.h"\r
+#include "./prefix.h"\r
+#include "./state.h"\r
+#include "./transform.h"\r
+\r
+#if defined(__cplusplus) || defined(c_plusplus)\r
+extern "C" {\r
+#endif\r
+\r
+#define BROTLI_FAILURE(CODE) (BROTLI_DUMP(), CODE)\r
+\r
+#define BROTLI_LOG_UINT(name) \\r
+ BROTLI_LOG(("[%s] %s = %lu\n", __func__, #name, (unsigned long)(name)))\r
+#define BROTLI_LOG_ARRAY_INDEX(array_name, idx) \\r
+ BROTLI_LOG(("[%s] %s[%lu] = %lu\n", __func__, #array_name, \\r
+ (unsigned long)(idx), (unsigned long)array_name[idx]))\r
+\r
+#define HUFFMAN_TABLE_BITS 8U\r
+#define HUFFMAN_TABLE_MASK 0xff\r
+\r
+static const uint8_t kCodeLengthCodeOrder[BROTLI_CODE_LENGTH_CODES] = {\r
+ 1, 2, 3, 4, 0, 5, 17, 6, 16, 7, 8, 9, 10, 11, 12, 13, 14, 15,\r
+};\r
+\r
+/* Static prefix code for the complex code length code lengths. */\r
+static const uint8_t kCodeLengthPrefixLength[16] = {\r
+ 2, 2, 2, 3, 2, 2, 2, 4, 2, 2, 2, 3, 2, 2, 2, 4,\r
+};\r
+\r
+static const uint8_t kCodeLengthPrefixValue[16] = {\r
+ 0, 4, 3, 2, 0, 4, 3, 1, 0, 4, 3, 2, 0, 4, 3, 5,\r
+};\r
+\r
+BrotliDecoderState* BrotliDecoderCreateInstance(\r
+ brotli_alloc_func alloc_func, brotli_free_func free_func, void* opaque) {\r
+ BrotliDecoderState* state = 0;\r
+ if (!alloc_func && !free_func) {\r
+ state = (BrotliDecoderState*)malloc(sizeof(BrotliDecoderState));\r
+ } else if (alloc_func && free_func) {\r
+ state = (BrotliDecoderState*)alloc_func(opaque, sizeof(BrotliDecoderState));\r
+ }\r
+ if (state == 0) {\r
+ BROTLI_DUMP();\r
+ return 0;\r
+ }\r
+ BrotliDecoderStateInitWithCustomAllocators(\r
+ state, alloc_func, free_func, opaque);\r
+ state->error_code = BROTLI_DECODER_NO_ERROR;\r
+ return state;\r
+}\r
+\r
+/* Deinitializes and frees BrotliDecoderState instance. */\r
+void BrotliDecoderDestroyInstance(BrotliDecoderState* state) {\r
+ if (!state) {\r
+ return;\r
+ } else {\r
+ brotli_free_func free_func = state->free_func;\r
+ void* opaque = state->memory_manager_opaque;\r
+ BrotliDecoderStateCleanup(state);\r
+ free_func(opaque, state);\r
+ }\r
+}\r
+\r
+/* Saves error code and converts it to BrotliDecoderResult */\r
+static BROTLI_NOINLINE BrotliDecoderResult SaveErrorCode(\r
+ BrotliDecoderState* s, BrotliDecoderErrorCode e) {\r
+ s->error_code = (int)e;\r
+ switch (e) {\r
+ case BROTLI_DECODER_SUCCESS:\r
+ return BROTLI_DECODER_RESULT_SUCCESS;\r
+ case BROTLI_DECODER_NEEDS_MORE_INPUT:\r
+ return BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT;\r
+ case BROTLI_DECODER_NEEDS_MORE_OUTPUT:\r
+ return BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT;\r
+ default:\r
+ return BROTLI_DECODER_RESULT_ERROR;\r
+ }\r
+}\r
+\r
+/* Decodes a number in the range [9..24], by reading 1 - 7 bits.\r
+ Precondition: bit-reader accumulator has at least 7 bits. */\r
+static uint32_t DecodeWindowBits(BrotliBitReader* br) {\r
+ uint32_t n;\r
+ BrotliTakeBits(br, 1, &n);\r
+ if (n == 0) {\r
+ return 16;\r
+ }\r
+ BrotliTakeBits(br, 3, &n);\r
+ if (n != 0) {\r
+ return 17 + n;\r
+ }\r
+ BrotliTakeBits(br, 3, &n);\r
+ if (n != 0) {\r
+ return 8 + n;\r
+ }\r
+ return 17;\r
+}\r
+\r
+static BROTLI_INLINE void memmove16(uint8_t* dst, uint8_t* src) {\r
+#if defined(__ARM_NEON__)\r
+ vst1q_u8(dst, vld1q_u8(src));\r
+#else\r
+ uint32_t buffer[4];\r
+ memcpy(buffer, src, 16);\r
+ memcpy(dst, buffer, 16);\r
+#endif\r
+}\r
+\r
+/* Decodes a number in the range [0..255], by reading 1 - 11 bits. */\r
+static BROTLI_NOINLINE BrotliDecoderErrorCode DecodeVarLenUint8(\r
+ BrotliDecoderState* s, BrotliBitReader* br, uint32_t* value) {\r
+ uint32_t bits;\r
+ switch (s->substate_decode_uint8) {\r
+ case BROTLI_STATE_DECODE_UINT8_NONE:\r
+ if (PREDICT_FALSE(!BrotliSafeReadBits(br, 1, &bits))) {\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ if (bits == 0) {\r
+ *value = 0;\r
+ return BROTLI_DECODER_SUCCESS;\r
+ }\r
+ /* No break, transit to the next state. */\r
+\r
+ case BROTLI_STATE_DECODE_UINT8_SHORT:\r
+ if (PREDICT_FALSE(!BrotliSafeReadBits(br, 3, &bits))) {\r
+ s->substate_decode_uint8 = BROTLI_STATE_DECODE_UINT8_SHORT;\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ if (bits == 0) {\r
+ *value = 1;\r
+ s->substate_decode_uint8 = BROTLI_STATE_DECODE_UINT8_NONE;\r
+ return BROTLI_DECODER_SUCCESS;\r
+ }\r
+ /* Use output value as a temporary storage. It MUST be persisted. */\r
+ *value = bits;\r
+ /* No break, transit to the next state. */\r
+\r
+ case BROTLI_STATE_DECODE_UINT8_LONG:\r
+ if (PREDICT_FALSE(!BrotliSafeReadBits(br, *value, &bits))) {\r
+ s->substate_decode_uint8 = BROTLI_STATE_DECODE_UINT8_LONG;\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ *value = (1U << *value) + bits;\r
+ s->substate_decode_uint8 = BROTLI_STATE_DECODE_UINT8_NONE;\r
+ return BROTLI_DECODER_SUCCESS;\r
+\r
+ default:\r
+ return\r
+ BROTLI_FAILURE(BROTLI_DECODER_ERROR_UNREACHABLE);\r
+ }\r
+}\r
+\r
+/* Decodes a metablock length and flags by reading 2 - 31 bits. */\r
+static BrotliDecoderErrorCode BROTLI_NOINLINE DecodeMetaBlockLength(\r
+ BrotliDecoderState* s, BrotliBitReader* br) {\r
+ uint32_t bits;\r
+ int i;\r
+ for (;;) {\r
+ switch (s->substate_metablock_header) {\r
+ case BROTLI_STATE_METABLOCK_HEADER_NONE:\r
+ if (!BrotliSafeReadBits(br, 1, &bits)) {\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ s->is_last_metablock = (uint8_t)bits;\r
+ s->meta_block_remaining_len = 0;\r
+ s->is_uncompressed = 0;\r
+ s->is_metadata = 0;\r
+ if (!s->is_last_metablock) {\r
+ s->substate_metablock_header = BROTLI_STATE_METABLOCK_HEADER_NIBBLES;\r
+ break;\r
+ }\r
+ s->substate_metablock_header = BROTLI_STATE_METABLOCK_HEADER_EMPTY;\r
+ /* No break, transit to the next state. */\r
+\r
+ case BROTLI_STATE_METABLOCK_HEADER_EMPTY:\r
+ if (!BrotliSafeReadBits(br, 1, &bits)) {\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ if (bits) {\r
+ s->substate_metablock_header = BROTLI_STATE_METABLOCK_HEADER_NONE;\r
+ return BROTLI_DECODER_SUCCESS;\r
+ }\r
+ s->substate_metablock_header = BROTLI_STATE_METABLOCK_HEADER_NIBBLES;\r
+ /* No break, transit to the next state. */\r
+\r
+ case BROTLI_STATE_METABLOCK_HEADER_NIBBLES:\r
+ if (!BrotliSafeReadBits(br, 2, &bits)) {\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ s->size_nibbles = (uint8_t)(bits + 4);\r
+ s->loop_counter = 0;\r
+ if (bits == 3) {\r
+ s->is_metadata = 1;\r
+ s->substate_metablock_header = BROTLI_STATE_METABLOCK_HEADER_RESERVED;\r
+ break;\r
+ }\r
+ s->substate_metablock_header = BROTLI_STATE_METABLOCK_HEADER_SIZE;\r
+ /* No break, transit to the next state. */\r
+\r
+ case BROTLI_STATE_METABLOCK_HEADER_SIZE:\r
+ i = s->loop_counter;\r
+ for (; i < s->size_nibbles; ++i) {\r
+ if (!BrotliSafeReadBits(br, 4, &bits)) {\r
+ s->loop_counter = i;\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ if (i + 1 == s->size_nibbles && s->size_nibbles > 4 && bits == 0) {\r
+ return BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_EXUBERANT_NIBBLE);\r
+ }\r
+ s->meta_block_remaining_len |= (int)(bits << (i * 4));\r
+ }\r
+ s->substate_metablock_header =\r
+ BROTLI_STATE_METABLOCK_HEADER_UNCOMPRESSED;\r
+ /* No break, transit to the next state. */\r
+\r
+ case BROTLI_STATE_METABLOCK_HEADER_UNCOMPRESSED:\r
+ if (!s->is_last_metablock) {\r
+ if (!BrotliSafeReadBits(br, 1, &bits)) {\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ s->is_uncompressed = (uint8_t)bits;\r
+ }\r
+ ++s->meta_block_remaining_len;\r
+ s->substate_metablock_header = BROTLI_STATE_METABLOCK_HEADER_NONE;\r
+ return BROTLI_DECODER_SUCCESS;\r
+\r
+ case BROTLI_STATE_METABLOCK_HEADER_RESERVED:\r
+ if (!BrotliSafeReadBits(br, 1, &bits)) {\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ if (bits != 0) {\r
+ return BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_RESERVED);\r
+ }\r
+ s->substate_metablock_header = BROTLI_STATE_METABLOCK_HEADER_BYTES;\r
+ /* No break, transit to the next state. */\r
+\r
+ case BROTLI_STATE_METABLOCK_HEADER_BYTES:\r
+ if (!BrotliSafeReadBits(br, 2, &bits)) {\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ if (bits == 0) {\r
+ s->substate_metablock_header = BROTLI_STATE_METABLOCK_HEADER_NONE;\r
+ return BROTLI_DECODER_SUCCESS;\r
+ }\r
+ s->size_nibbles = (uint8_t)bits;\r
+ s->substate_metablock_header = BROTLI_STATE_METABLOCK_HEADER_METADATA;\r
+ /* No break, transit to the next state. */\r
+\r
+ case BROTLI_STATE_METABLOCK_HEADER_METADATA:\r
+ i = s->loop_counter;\r
+ for (; i < s->size_nibbles; ++i) {\r
+ if (!BrotliSafeReadBits(br, 8, &bits)) {\r
+ s->loop_counter = i;\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ if (i + 1 == s->size_nibbles && s->size_nibbles > 1 && bits == 0) {\r
+ return BROTLI_FAILURE(\r
+ BROTLI_DECODER_ERROR_FORMAT_EXUBERANT_META_NIBBLE);\r
+ }\r
+ s->meta_block_remaining_len |= (int)(bits << (i * 8));\r
+ }\r
+ ++s->meta_block_remaining_len;\r
+ s->substate_metablock_header = BROTLI_STATE_METABLOCK_HEADER_NONE;\r
+ return BROTLI_DECODER_SUCCESS;\r
+\r
+ default:\r
+ return\r
+ BROTLI_FAILURE(BROTLI_DECODER_ERROR_UNREACHABLE);\r
+ }\r
+ }\r
+}\r
+\r
+/* Decodes the Huffman code.\r
+ This method doesn't read data from the bit reader, BUT drops the amount of\r
+ bits that correspond to the decoded symbol.\r
+ bits MUST contain at least 15 (BROTLI_HUFFMAN_MAX_CODE_LENGTH) valid bits. */\r
+static BROTLI_INLINE uint32_t DecodeSymbol(uint32_t bits,\r
+ const HuffmanCode* table,\r
+ BrotliBitReader* br) {\r
+ table += bits & HUFFMAN_TABLE_MASK;\r
+ if (table->bits > HUFFMAN_TABLE_BITS) {\r
+ uint32_t nbits = table->bits - HUFFMAN_TABLE_BITS;\r
+ BrotliDropBits(br, HUFFMAN_TABLE_BITS);\r
+ table += table->value;\r
+ table += (bits >> HUFFMAN_TABLE_BITS) & BitMask(nbits);\r
+ }\r
+ BrotliDropBits(br, table->bits);\r
+ return table->value;\r
+}\r
+\r
+/* Reads and decodes the next Huffman code from bit-stream.\r
+ This method peeks 16 bits of input and drops 0 - 15 of them. */\r
+static BROTLI_INLINE uint32_t ReadSymbol(const HuffmanCode* table,\r
+ BrotliBitReader* br) {\r
+ return DecodeSymbol(BrotliGet16BitsUnmasked(br), table, br);\r
+}\r
+\r
+/* Same as DecodeSymbol, but it is known that there is less than 15 bits of\r
+ input are currently available. */\r
+static BROTLI_NOINLINE BROTLI_BOOL SafeDecodeSymbol(\r
+ const HuffmanCode* table, BrotliBitReader* br, uint32_t* result) {\r
+ uint32_t val;\r
+ uint32_t available_bits = BrotliGetAvailableBits(br);\r
+ if (available_bits == 0) {\r
+ if (table->bits == 0) {\r
+ *result = table->value;\r
+ return BROTLI_TRUE;\r
+ }\r
+ return BROTLI_FALSE; /* No valid bits at all. */\r
+ }\r
+ val = (uint32_t)BrotliGetBitsUnmasked(br);\r
+ table += val & HUFFMAN_TABLE_MASK;\r
+ if (table->bits <= HUFFMAN_TABLE_BITS) {\r
+ if (table->bits <= available_bits) {\r
+ BrotliDropBits(br, table->bits);\r
+ *result = table->value;\r
+ return BROTLI_TRUE;\r
+ } else {\r
+ return BROTLI_FALSE; /* Not enough bits for the first level. */\r
+ }\r
+ }\r
+ if (available_bits <= HUFFMAN_TABLE_BITS) {\r
+ return BROTLI_FALSE; /* Not enough bits to move to the second level. */\r
+ }\r
+\r
+ /* Speculatively drop HUFFMAN_TABLE_BITS. */\r
+ val = (val & BitMask(table->bits)) >> HUFFMAN_TABLE_BITS;\r
+ available_bits -= HUFFMAN_TABLE_BITS;\r
+ table += table->value + val;\r
+ if (available_bits < table->bits) {\r
+ return BROTLI_FALSE; /* Not enough bits for the second level. */\r
+ }\r
+\r
+ BrotliDropBits(br, HUFFMAN_TABLE_BITS + table->bits);\r
+ *result = table->value;\r
+ return BROTLI_TRUE;\r
+}\r
+\r
+static BROTLI_INLINE BROTLI_BOOL SafeReadSymbol(\r
+ const HuffmanCode* table, BrotliBitReader* br, uint32_t* result) {\r
+ uint32_t val;\r
+ if (PREDICT_TRUE(BrotliSafeGetBits(br, 15, &val))) {\r
+ *result = DecodeSymbol(val, table, br);\r
+ return BROTLI_TRUE;\r
+ }\r
+ return SafeDecodeSymbol(table, br, result);\r
+}\r
+\r
+/* Makes a look-up in first level Huffman table. Peeks 8 bits. */\r
+static BROTLI_INLINE void PreloadSymbol(int safe,\r
+ const HuffmanCode* table,\r
+ BrotliBitReader* br,\r
+ uint32_t* bits,\r
+ uint32_t* value) {\r
+ if (safe) {\r
+ return;\r
+ }\r
+ table += BrotliGetBits(br, HUFFMAN_TABLE_BITS);\r
+ *bits = table->bits;\r
+ *value = table->value;\r
+}\r
+\r
+/* Decodes the next Huffman code using data prepared by PreloadSymbol.\r
+ Reads 0 - 15 bits. Also peeks 8 following bits. */\r
+static BROTLI_INLINE uint32_t ReadPreloadedSymbol(const HuffmanCode* table,\r
+ BrotliBitReader* br,\r
+ uint32_t* bits,\r
+ uint32_t* value) {\r
+ uint32_t result = *value;\r
+ if (PREDICT_FALSE(*bits > HUFFMAN_TABLE_BITS)) {\r
+ uint32_t val = BrotliGet16BitsUnmasked(br);\r
+ const HuffmanCode* ext = table + (val & HUFFMAN_TABLE_MASK) + *value;\r
+ uint32_t mask = BitMask((*bits - HUFFMAN_TABLE_BITS));\r
+ BrotliDropBits(br, HUFFMAN_TABLE_BITS);\r
+ ext += (val >> HUFFMAN_TABLE_BITS) & mask;\r
+ BrotliDropBits(br, ext->bits);\r
+ result = ext->value;\r
+ } else {\r
+ BrotliDropBits(br, *bits);\r
+ }\r
+ PreloadSymbol(0, table, br, bits, value);\r
+ return result;\r
+}\r
+\r
+static BROTLI_INLINE uint32_t Log2Floor(uint32_t x) {\r
+ uint32_t result = 0;\r
+ while (x) {\r
+ x >>= 1;\r
+ ++result;\r
+ }\r
+ return result;\r
+}\r
+\r
+/* Reads (s->symbol + 1) symbols.\r
+ Totally 1..4 symbols are read, 1..10 bits each.\r
+ The list of symbols MUST NOT contain duplicates.\r
+ */\r
+static BrotliDecoderErrorCode ReadSimpleHuffmanSymbols(\r
+ uint32_t alphabet_size, BrotliDecoderState* s) {\r
+ /* max_bits == 1..10; symbol == 0..3; 1..40 bits will be read. */\r
+ BrotliBitReader* br = &s->br;\r
+ uint32_t max_bits = Log2Floor(alphabet_size - 1);\r
+ uint32_t i = s->sub_loop_counter;\r
+ uint32_t num_symbols = s->symbol;\r
+ while (i <= num_symbols) {\r
+ uint32_t v;\r
+ if (PREDICT_FALSE(!BrotliSafeReadBits(br, max_bits, &v))) {\r
+ s->sub_loop_counter = i;\r
+ s->substate_huffman = BROTLI_STATE_HUFFMAN_SIMPLE_READ;\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ if (v >= alphabet_size) {\r
+ return\r
+ BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_SIMPLE_HUFFMAN_ALPHABET);\r
+ }\r
+ s->symbols_lists_array[i] = (uint16_t)v;\r
+ BROTLI_LOG_UINT(s->symbols_lists_array[i]);\r
+ ++i;\r
+ }\r
+\r
+ for (i = 0; i < num_symbols; ++i) {\r
+ uint32_t k = i + 1;\r
+ for (; k <= num_symbols; ++k) {\r
+ if (s->symbols_lists_array[i] == s->symbols_lists_array[k]) {\r
+ return BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_SIMPLE_HUFFMAN_SAME);\r
+ }\r
+ }\r
+ }\r
+\r
+ return BROTLI_DECODER_SUCCESS;\r
+}\r
+\r
+/* Process single decoded symbol code length:\r
+ A) reset the repeat variable\r
+ B) remember code length (if it is not 0)\r
+ C) extend corredponding index-chain\r
+ D) reduce the huffman space\r
+ E) update the histogram\r
+ */\r
+static BROTLI_INLINE void ProcessSingleCodeLength(uint32_t code_len,\r
+ uint32_t* symbol, uint32_t* repeat, uint32_t* space,\r
+ uint32_t* prev_code_len, uint16_t* symbol_lists,\r
+ uint16_t* code_length_histo, int* next_symbol) {\r
+ *repeat = 0;\r
+ if (code_len != 0) { /* code_len == 1..15 */\r
+ symbol_lists[next_symbol[code_len]] = (uint16_t)(*symbol);\r
+ next_symbol[code_len] = (int)(*symbol);\r
+ *prev_code_len = code_len;\r
+ *space -= 32768U >> code_len;\r
+ code_length_histo[code_len]++;\r
+ BROTLI_LOG(("[ReadHuffmanCode] code_length[%d] = %d\n", *symbol, code_len));\r
+ }\r
+ (*symbol)++;\r
+}\r
+\r
+/* Process repeated symbol code length.\r
+ A) Check if it is the extension of previous repeat sequence; if the decoded\r
+ value is not BROTLI_REPEAT_PREVIOUS_CODE_LENGTH, then it is a new\r
+ symbol-skip\r
+ B) Update repeat variable\r
+ C) Check if operation is feasible (fits alphapet)\r
+ D) For each symbol do the same operations as in ProcessSingleCodeLength\r
+\r
+ PRECONDITION: code_len == BROTLI_REPEAT_PREVIOUS_CODE_LENGTH or\r
+ code_len == BROTLI_REPEAT_ZERO_CODE_LENGTH\r
+ */\r
+static BROTLI_INLINE void ProcessRepeatedCodeLength(uint32_t code_len,\r
+ uint32_t repeat_delta, uint32_t alphabet_size, uint32_t* symbol,\r
+ uint32_t* repeat, uint32_t* space, uint32_t* prev_code_len,\r
+ uint32_t* repeat_code_len, uint16_t* symbol_lists,\r
+ uint16_t* code_length_histo, int* next_symbol) {\r
+ uint32_t old_repeat;\r
+ uint32_t extra_bits = 3; /* for BROTLI_REPEAT_ZERO_CODE_LENGTH */\r
+ uint32_t new_len = 0; /* for BROTLI_REPEAT_ZERO_CODE_LENGTH */\r
+ if (code_len == BROTLI_REPEAT_PREVIOUS_CODE_LENGTH) {\r
+ new_len = *prev_code_len;\r
+ extra_bits = 2;\r
+ }\r
+ if (*repeat_code_len != new_len) {\r
+ *repeat = 0;\r
+ *repeat_code_len = new_len;\r
+ }\r
+ old_repeat = *repeat;\r
+ if (*repeat > 0) {\r
+ *repeat -= 2;\r
+ *repeat <<= extra_bits;\r
+ }\r
+ *repeat += repeat_delta + 3U;\r
+ repeat_delta = *repeat - old_repeat;\r
+ if (*symbol + repeat_delta > alphabet_size) {\r
+ BROTLI_DUMP();\r
+ *symbol = alphabet_size;\r
+ *space = 0xFFFFF;\r
+ return;\r
+ }\r
+ BROTLI_LOG(("[ReadHuffmanCode] code_length[%d..%d] = %d\n",\r
+ *symbol, *symbol + repeat_delta - 1, *repeat_code_len));\r
+ if (*repeat_code_len != 0) {\r
+ unsigned last = *symbol + repeat_delta;\r
+ int next = next_symbol[*repeat_code_len];\r
+ do {\r
+ symbol_lists[next] = (uint16_t)*symbol;\r
+ next = (int)*symbol;\r
+ } while (++(*symbol) != last);\r
+ next_symbol[*repeat_code_len] = next;\r
+ *space -= repeat_delta << (15 - *repeat_code_len);\r
+ code_length_histo[*repeat_code_len] =\r
+ (uint16_t)(code_length_histo[*repeat_code_len] + repeat_delta);\r
+ } else {\r
+ *symbol += repeat_delta;\r
+ }\r
+}\r
+\r
+/* Reads and decodes symbol codelengths. */\r
+static BrotliDecoderErrorCode ReadSymbolCodeLengths(\r
+ uint32_t alphabet_size, BrotliDecoderState* s) {\r
+ BrotliBitReader* br = &s->br;\r
+ uint32_t symbol = s->symbol;\r
+ uint32_t repeat = s->repeat;\r
+ uint32_t space = s->space;\r
+ uint32_t prev_code_len = s->prev_code_len;\r
+ uint32_t repeat_code_len = s->repeat_code_len;\r
+ uint16_t* symbol_lists = s->symbol_lists;\r
+ uint16_t* code_length_histo = s->code_length_histo;\r
+ int* next_symbol = s->next_symbol;\r
+ if (!BrotliWarmupBitReader(br)) {\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ while (symbol < alphabet_size && space > 0) {\r
+ const HuffmanCode* p = s->table;\r
+ uint32_t code_len;\r
+ if (!BrotliCheckInputAmount(br, BROTLI_SHORT_FILL_BIT_WINDOW_READ)) {\r
+ s->symbol = symbol;\r
+ s->repeat = repeat;\r
+ s->prev_code_len = prev_code_len;\r
+ s->repeat_code_len = repeat_code_len;\r
+ s->space = space;\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ BrotliFillBitWindow16(br);\r
+ p += BrotliGetBitsUnmasked(br) &\r
+ BitMask(BROTLI_HUFFMAN_MAX_CODE_LENGTH_CODE_LENGTH);\r
+ BrotliDropBits(br, p->bits); /* Use 1..5 bits */\r
+ code_len = p->value; /* code_len == 0..17 */\r
+ if (code_len < BROTLI_REPEAT_PREVIOUS_CODE_LENGTH) {\r
+ ProcessSingleCodeLength(code_len, &symbol, &repeat, &space,\r
+ &prev_code_len, symbol_lists, code_length_histo, next_symbol);\r
+ } else { /* code_len == 16..17, extra_bits == 2..3 */\r
+ uint32_t extra_bits =\r
+ (code_len == BROTLI_REPEAT_PREVIOUS_CODE_LENGTH) ? 2 : 3;\r
+ uint32_t repeat_delta =\r
+ (uint32_t)BrotliGetBitsUnmasked(br) & BitMask(extra_bits);\r
+ BrotliDropBits(br, extra_bits);\r
+ ProcessRepeatedCodeLength(code_len, repeat_delta, alphabet_size,\r
+ &symbol, &repeat, &space, &prev_code_len, &repeat_code_len,\r
+ symbol_lists, code_length_histo, next_symbol);\r
+ }\r
+ }\r
+ s->space = space;\r
+ return BROTLI_DECODER_SUCCESS;\r
+}\r
+\r
+static BrotliDecoderErrorCode SafeReadSymbolCodeLengths(\r
+ uint32_t alphabet_size, BrotliDecoderState* s) {\r
+ BrotliBitReader* br = &s->br;\r
+ while (s->symbol < alphabet_size && s->space > 0) {\r
+ const HuffmanCode* p = s->table;\r
+ uint32_t code_len;\r
+ uint32_t bits = 0;\r
+ uint32_t available_bits = BrotliGetAvailableBits(br);\r
+ if (available_bits != 0) {\r
+ bits = (uint32_t)BrotliGetBitsUnmasked(br);\r
+ }\r
+ p += bits & BitMask(BROTLI_HUFFMAN_MAX_CODE_LENGTH_CODE_LENGTH);\r
+ if (p->bits > available_bits) goto pullMoreInput;\r
+ code_len = p->value; /* code_len == 0..17 */\r
+ if (code_len < BROTLI_REPEAT_PREVIOUS_CODE_LENGTH) {\r
+ BrotliDropBits(br, p->bits);\r
+ ProcessSingleCodeLength(code_len, &s->symbol, &s->repeat, &s->space,\r
+ &s->prev_code_len, s->symbol_lists, s->code_length_histo,\r
+ s->next_symbol);\r
+ } else { /* code_len == 16..17, extra_bits == 2..3 */\r
+ uint32_t extra_bits = code_len - 14U;\r
+ uint32_t repeat_delta = (bits >> p->bits) & BitMask(extra_bits);\r
+ if (available_bits < p->bits + extra_bits) goto pullMoreInput;\r
+ BrotliDropBits(br, p->bits + extra_bits);\r
+ ProcessRepeatedCodeLength(code_len, repeat_delta, alphabet_size,\r
+ &s->symbol, &s->repeat, &s->space, &s->prev_code_len,\r
+ &s->repeat_code_len, s->symbol_lists, s->code_length_histo,\r
+ s->next_symbol);\r
+ }\r
+ continue;\r
+\r
+pullMoreInput:\r
+ if (!BrotliPullByte(br)) {\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ }\r
+ return BROTLI_DECODER_SUCCESS;\r
+}\r
+\r
+/* Reads and decodes 15..18 codes using static prefix code.\r
+ Each code is 2..4 bits long. In total 30..72 bits are used. */\r
+static BrotliDecoderErrorCode ReadCodeLengthCodeLengths(BrotliDecoderState* s) {\r
+ BrotliBitReader* br = &s->br;\r
+ uint32_t num_codes = s->repeat;\r
+ unsigned space = s->space;\r
+ uint32_t i = s->sub_loop_counter;\r
+ for (; i < BROTLI_CODE_LENGTH_CODES; ++i) {\r
+ const uint8_t code_len_idx = kCodeLengthCodeOrder[i];\r
+ uint32_t ix;\r
+ uint32_t v;\r
+ if (PREDICT_FALSE(!BrotliSafeGetBits(br, 4, &ix))) {\r
+ uint32_t available_bits = BrotliGetAvailableBits(br);\r
+ if (available_bits != 0) {\r
+ ix = BrotliGetBitsUnmasked(br) & 0xF;\r
+ } else {\r
+ ix = 0;\r
+ }\r
+ if (kCodeLengthPrefixLength[ix] > available_bits) {\r
+ s->sub_loop_counter = i;\r
+ s->repeat = num_codes;\r
+ s->space = space;\r
+ s->substate_huffman = BROTLI_STATE_HUFFMAN_COMPLEX;\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ }\r
+ v = kCodeLengthPrefixValue[ix];\r
+ BrotliDropBits(br, kCodeLengthPrefixLength[ix]);\r
+ s->code_length_code_lengths[code_len_idx] = (uint8_t)v;\r
+ BROTLI_LOG_ARRAY_INDEX(s->code_length_code_lengths, code_len_idx);\r
+ if (v != 0) {\r
+ space = space - (32U >> v);\r
+ ++num_codes;\r
+ ++s->code_length_histo[v];\r
+ if (space - 1U >= 32U) {\r
+ /* space is 0 or wrapped around */\r
+ break;\r
+ }\r
+ }\r
+ }\r
+ if (!(num_codes == 1 || space == 0)) {\r
+ return BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_CL_SPACE);\r
+ }\r
+ return BROTLI_DECODER_SUCCESS;\r
+}\r
+\r
+/* Decodes the Huffman tables.\r
+ There are 2 scenarios:\r
+ A) Huffman code contains only few symbols (1..4). Those symbols are read\r
+ directly; their code lengths are defined by the number of symbols.\r
+ For this scenario 4 - 45 bits will be read.\r
+\r
+ B) 2-phase decoding:\r
+ B.1) Small Huffman table is decoded; it is specified with code lengths\r
+ encoded with predefined entropy code. 32 - 74 bits are used.\r
+ B.2) Decoded table is used to decode code lengths of symbols in resulting\r
+ Huffman table. In worst case 3520 bits are read.\r
+*/\r
+static BrotliDecoderErrorCode ReadHuffmanCode(uint32_t alphabet_size,\r
+ HuffmanCode* table,\r
+ uint32_t* opt_table_size,\r
+ BrotliDecoderState* s) {\r
+ BrotliBitReader* br = &s->br;\r
+ /* Unnecessary masking, but might be good for safety. */\r
+ alphabet_size &= 0x3ff;\r
+ /* State machine */\r
+ switch (s->substate_huffman) {\r
+ case BROTLI_STATE_HUFFMAN_NONE:\r
+ if (!BrotliSafeReadBits(br, 2, &s->sub_loop_counter)) {\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ BROTLI_LOG_UINT(s->sub_loop_counter);\r
+ /* The value is used as follows:\r
+ 1 for simple code;\r
+ 0 for no skipping, 2 skips 2 code lengths, 3 skips 3 code lengths */\r
+ if (s->sub_loop_counter != 1) {\r
+ s->space = 32;\r
+ s->repeat = 0; /* num_codes */\r
+ memset(&s->code_length_histo[0], 0, sizeof(s->code_length_histo[0]) *\r
+ (BROTLI_HUFFMAN_MAX_CODE_LENGTH_CODE_LENGTH + 1));\r
+ memset(&s->code_length_code_lengths[0], 0,\r
+ sizeof(s->code_length_code_lengths));\r
+ s->substate_huffman = BROTLI_STATE_HUFFMAN_COMPLEX;\r
+ goto Complex;\r
+ }\r
+ /* No break, transit to the next state. */\r
+\r
+ case BROTLI_STATE_HUFFMAN_SIMPLE_SIZE:\r
+ /* Read symbols, codes & code lengths directly. */\r
+ if (!BrotliSafeReadBits(br, 2, &s->symbol)) { /* num_symbols */\r
+ s->substate_huffman = BROTLI_STATE_HUFFMAN_SIMPLE_SIZE;\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ s->sub_loop_counter = 0;\r
+ /* No break, transit to the next state. */\r
+ case BROTLI_STATE_HUFFMAN_SIMPLE_READ: {\r
+ BrotliDecoderErrorCode result =\r
+ ReadSimpleHuffmanSymbols(alphabet_size, s);\r
+ if (result != BROTLI_DECODER_SUCCESS) {\r
+ return result;\r
+ }\r
+ /* No break, transit to the next state. */\r
+ }\r
+ case BROTLI_STATE_HUFFMAN_SIMPLE_BUILD: {\r
+ uint32_t table_size;\r
+ if (s->symbol == 3) {\r
+ uint32_t bits;\r
+ if (!BrotliSafeReadBits(br, 1, &bits)) {\r
+ s->substate_huffman = BROTLI_STATE_HUFFMAN_SIMPLE_BUILD;\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ s->symbol += bits;\r
+ }\r
+ BROTLI_LOG_UINT(s->symbol);\r
+ table_size = BrotliBuildSimpleHuffmanTable(\r
+ table, HUFFMAN_TABLE_BITS, s->symbols_lists_array, s->symbol);\r
+ if (opt_table_size) {\r
+ *opt_table_size = table_size;\r
+ }\r
+ s->substate_huffman = BROTLI_STATE_HUFFMAN_NONE;\r
+ return BROTLI_DECODER_SUCCESS;\r
+ }\r
+\r
+Complex: /* Decode Huffman-coded code lengths. */\r
+ case BROTLI_STATE_HUFFMAN_COMPLEX: {\r
+ uint32_t i;\r
+ BrotliDecoderErrorCode result = ReadCodeLengthCodeLengths(s);\r
+ if (result != BROTLI_DECODER_SUCCESS) {\r
+ return result;\r
+ }\r
+ BrotliBuildCodeLengthsHuffmanTable(s->table,\r
+ s->code_length_code_lengths,\r
+ s->code_length_histo);\r
+ memset(&s->code_length_histo[0], 0, sizeof(s->code_length_histo));\r
+ for (i = 0; i <= BROTLI_HUFFMAN_MAX_CODE_LENGTH; ++i) {\r
+ s->next_symbol[i] = (int)i - (BROTLI_HUFFMAN_MAX_CODE_LENGTH + 1);\r
+ s->symbol_lists[(int)i - (BROTLI_HUFFMAN_MAX_CODE_LENGTH + 1)] = 0xFFFF;\r
+ }\r
+\r
+ s->symbol = 0;\r
+ s->prev_code_len = BROTLI_INITIAL_REPEATED_CODE_LENGTH;\r
+ s->repeat = 0;\r
+ s->repeat_code_len = 0;\r
+ s->space = 32768;\r
+ s->substate_huffman = BROTLI_STATE_HUFFMAN_LENGTH_SYMBOLS;\r
+ /* No break, transit to the next state. */\r
+ }\r
+ case BROTLI_STATE_HUFFMAN_LENGTH_SYMBOLS: {\r
+ uint32_t table_size;\r
+ BrotliDecoderErrorCode result = ReadSymbolCodeLengths(alphabet_size, s);\r
+ if (result == BROTLI_DECODER_NEEDS_MORE_INPUT) {\r
+ result = SafeReadSymbolCodeLengths(alphabet_size, s);\r
+ }\r
+ if (result != BROTLI_DECODER_SUCCESS) {\r
+ return result;\r
+ }\r
+\r
+ if (s->space != 0) {\r
+ BROTLI_LOG(("[ReadHuffmanCode] space = %d\n", s->space));\r
+ return BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_HUFFMAN_SPACE);\r
+ }\r
+ table_size = BrotliBuildHuffmanTable(\r
+ table, HUFFMAN_TABLE_BITS, s->symbol_lists, s->code_length_histo);\r
+ if (opt_table_size) {\r
+ *opt_table_size = table_size;\r
+ }\r
+ s->substate_huffman = BROTLI_STATE_HUFFMAN_NONE;\r
+ return BROTLI_DECODER_SUCCESS;\r
+ }\r
+\r
+ default:\r
+ return\r
+ BROTLI_FAILURE(BROTLI_DECODER_ERROR_UNREACHABLE);\r
+ }\r
+}\r
+\r
+/* Decodes a block length by reading 3..39 bits. */\r
+static BROTLI_INLINE uint32_t ReadBlockLength(const HuffmanCode* table,\r
+ BrotliBitReader* br) {\r
+ uint32_t code;\r
+ uint32_t nbits;\r
+ code = ReadSymbol(table, br);\r
+ nbits = kBlockLengthPrefixCode[code].nbits; /* nbits == 2..24 */\r
+ return kBlockLengthPrefixCode[code].offset + BrotliReadBits(br, nbits);\r
+}\r
+\r
+/* WARNING: if state is not BROTLI_STATE_READ_BLOCK_LENGTH_NONE, then\r
+ reading can't be continued with ReadBlockLength. */\r
+static BROTLI_INLINE BROTLI_BOOL SafeReadBlockLength(\r
+ BrotliDecoderState* s, uint32_t* result, const HuffmanCode* table,\r
+ BrotliBitReader* br) {\r
+ uint32_t index;\r
+ if (s->substate_read_block_length == BROTLI_STATE_READ_BLOCK_LENGTH_NONE) {\r
+ if (!SafeReadSymbol(table, br, &index)) {\r
+ return BROTLI_FALSE;\r
+ }\r
+ } else {\r
+ index = s->block_length_index;\r
+ }\r
+ {\r
+ uint32_t bits;\r
+ uint32_t nbits = kBlockLengthPrefixCode[index].nbits; /* nbits == 2..24 */\r
+ if (!BrotliSafeReadBits(br, nbits, &bits)) {\r
+ s->block_length_index = index;\r
+ s->substate_read_block_length = BROTLI_STATE_READ_BLOCK_LENGTH_SUFFIX;\r
+ return BROTLI_FALSE;\r
+ }\r
+ *result = kBlockLengthPrefixCode[index].offset + bits;\r
+ s->substate_read_block_length = BROTLI_STATE_READ_BLOCK_LENGTH_NONE;\r
+ return BROTLI_TRUE;\r
+ }\r
+}\r
+\r
+/* Transform:\r
+ 1) initialize list L with values 0, 1,... 255\r
+ 2) For each input element X:\r
+ 2.1) let Y = L[X]\r
+ 2.2) remove X-th element from L\r
+ 2.3) prepend Y to L\r
+ 2.4) append Y to output\r
+\r
+ In most cases max(Y) <= 7, so most of L remains intact.\r
+ To reduce the cost of initialization, we reuse L, remember the upper bound\r
+ of Y values, and reinitialize only first elements in L.\r
+\r
+ Most of input values are 0 and 1. To reduce number of branches, we replace\r
+ inner for loop with do-while.\r
+ */\r
+static BROTLI_NOINLINE void InverseMoveToFrontTransform(\r
+ uint8_t* v, uint32_t v_len, BrotliDecoderState* state) {\r
+ /* Reinitialize elements that could have been changed. */\r
+ uint32_t i = 4;\r
+ uint32_t upper_bound = state->mtf_upper_bound;\r
+ uint8_t* mtf = &state->mtf[4]; /* Make mtf[-1] addressable. */\r
+ /* Load endian-aware constant. */\r
+ const uint8_t b0123[4] = {0, 1, 2, 3};\r
+ uint32_t pattern;\r
+ memcpy(&pattern, &b0123, 4);\r
+\r
+ /* Initialize list using 4 consequent values pattern. */\r
+ *(uint32_t*)mtf = pattern;\r
+ do {\r
+ pattern += 0x04040404; /* Advance all 4 values by 4. */\r
+ *(uint32_t*)(mtf + i) = pattern;\r
+ i += 4;\r
+ } while (i <= upper_bound);\r
+\r
+ /* Transform the input. */\r
+ upper_bound = 0;\r
+ for (i = 0; i < v_len; ++i) {\r
+ int index = v[i];\r
+ uint8_t value = mtf[index];\r
+ upper_bound |= v[i];\r
+ v[i] = value;\r
+ mtf[-1] = value;\r
+ do {\r
+ index--;\r
+ mtf[index + 1] = mtf[index];\r
+ } while (index >= 0);\r
+ }\r
+ /* Remember amount of elements to be reinitialized. */\r
+ state->mtf_upper_bound = upper_bound;\r
+}\r
+\r
+/* Decodes a series of Huffman table using ReadHuffmanCode function. */\r
+static BrotliDecoderErrorCode HuffmanTreeGroupDecode(\r
+ HuffmanTreeGroup* group, BrotliDecoderState* s) {\r
+ if (s->substate_tree_group != BROTLI_STATE_TREE_GROUP_LOOP) {\r
+ s->next = group->codes;\r
+ s->htree_index = 0;\r
+ s->substate_tree_group = BROTLI_STATE_TREE_GROUP_LOOP;\r
+ }\r
+ while (s->htree_index < group->num_htrees) {\r
+ uint32_t table_size;\r
+ BrotliDecoderErrorCode result =\r
+ ReadHuffmanCode(group->alphabet_size, s->next, &table_size, s);\r
+ if (result != BROTLI_DECODER_SUCCESS) return result;\r
+ group->htrees[s->htree_index] = s->next;\r
+ s->next += table_size;\r
+ ++s->htree_index;\r
+ }\r
+ s->substate_tree_group = BROTLI_STATE_TREE_GROUP_NONE;\r
+ return BROTLI_DECODER_SUCCESS;\r
+}\r
+\r
+/* Decodes a context map.\r
+ Decoding is done in 4 phases:\r
+ 1) Read auxiliary information (6..16 bits) and allocate memory.\r
+ In case of trivial context map, decoding is finished at this phase.\r
+ 2) Decode Huffman table using ReadHuffmanCode function.\r
+ This table will be used for reading context map items.\r
+ 3) Read context map items; "0" values could be run-length encoded.\r
+ 4) Optionally, apply InverseMoveToFront transform to the resulting map.\r
+ */\r
+static BrotliDecoderErrorCode DecodeContextMap(uint32_t context_map_size,\r
+ uint32_t* num_htrees,\r
+ uint8_t** context_map_arg,\r
+ BrotliDecoderState* s) {\r
+ BrotliBitReader* br = &s->br;\r
+ BrotliDecoderErrorCode result = BROTLI_DECODER_SUCCESS;\r
+\r
+ switch ((int)s->substate_context_map) {\r
+ case BROTLI_STATE_CONTEXT_MAP_NONE:\r
+ result = DecodeVarLenUint8(s, br, num_htrees);\r
+ if (result != BROTLI_DECODER_SUCCESS) {\r
+ return result;\r
+ }\r
+ (*num_htrees)++;\r
+ s->context_index = 0;\r
+ BROTLI_LOG_UINT(context_map_size);\r
+ BROTLI_LOG_UINT(*num_htrees);\r
+ *context_map_arg = (uint8_t*)BROTLI_ALLOC(s, (size_t)context_map_size);\r
+ if (*context_map_arg == 0) {\r
+ return BROTLI_FAILURE(BROTLI_DECODER_ERROR_ALLOC_CONTEXT_MAP);\r
+ }\r
+ if (*num_htrees <= 1) {\r
+ memset(*context_map_arg, 0, (size_t)context_map_size);\r
+ return BROTLI_DECODER_SUCCESS;\r
+ }\r
+ s->substate_context_map = BROTLI_STATE_CONTEXT_MAP_READ_PREFIX;\r
+ /* No break, continue to next state. */\r
+ case BROTLI_STATE_CONTEXT_MAP_READ_PREFIX: {\r
+ uint32_t bits;\r
+ /* In next stage ReadHuffmanCode uses at least 4 bits, so it is safe\r
+ to peek 4 bits ahead. */\r
+ if (!BrotliSafeGetBits(br, 5, &bits)) {\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ if ((bits & 1) != 0) { /* Use RLE for zeroes. */\r
+ s->max_run_length_prefix = (bits >> 1) + 1;\r
+ BrotliDropBits(br, 5);\r
+ } else {\r
+ s->max_run_length_prefix = 0;\r
+ BrotliDropBits(br, 1);\r
+ }\r
+ BROTLI_LOG_UINT(s->max_run_length_prefix);\r
+ s->substate_context_map = BROTLI_STATE_CONTEXT_MAP_HUFFMAN;\r
+ /* No break, continue to next state. */\r
+ }\r
+ case BROTLI_STATE_CONTEXT_MAP_HUFFMAN:\r
+ result = ReadHuffmanCode(*num_htrees + s->max_run_length_prefix,\r
+ s->context_map_table, NULL, s);\r
+ if (result != BROTLI_DECODER_SUCCESS) return result;\r
+ s->code = 0xFFFF;\r
+ s->substate_context_map = BROTLI_STATE_CONTEXT_MAP_DECODE;\r
+ /* No break, continue to next state. */\r
+ case BROTLI_STATE_CONTEXT_MAP_DECODE: {\r
+ uint32_t context_index = s->context_index;\r
+ uint32_t max_run_length_prefix = s->max_run_length_prefix;\r
+ uint8_t* context_map = *context_map_arg;\r
+ uint32_t code = s->code;\r
+ if (code != 0xFFFF) {\r
+ goto rleCode;\r
+ }\r
+ while (context_index < context_map_size) {\r
+ if (!SafeReadSymbol(s->context_map_table, br, &code)) {\r
+ s->code = 0xFFFF;\r
+ s->context_index = context_index;\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ BROTLI_LOG_UINT(code);\r
+\r
+ if (code == 0) {\r
+ context_map[context_index++] = 0;\r
+ continue;\r
+ }\r
+ if (code > max_run_length_prefix) {\r
+ context_map[context_index++] =\r
+ (uint8_t)(code - max_run_length_prefix);\r
+ continue;\r
+ }\r
+rleCode:\r
+ {\r
+ uint32_t reps;\r
+ if (!BrotliSafeReadBits(br, code, &reps)) {\r
+ s->code = code;\r
+ s->context_index = context_index;\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ reps += 1U << code;\r
+ BROTLI_LOG_UINT(reps);\r
+ if (context_index + reps > context_map_size) {\r
+ return\r
+ BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_CONTEXT_MAP_REPEAT);\r
+ }\r
+ do {\r
+ context_map[context_index++] = 0;\r
+ } while (--reps);\r
+ }\r
+ }\r
+ /* No break, continue to next state. */\r
+ }\r
+ case BROTLI_STATE_CONTEXT_MAP_TRANSFORM: {\r
+ uint32_t bits;\r
+ if (!BrotliSafeReadBits(br, 1, &bits)) {\r
+ s->substate_context_map = BROTLI_STATE_CONTEXT_MAP_TRANSFORM;\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ if (bits != 0) {\r
+ InverseMoveToFrontTransform(*context_map_arg, context_map_size, s);\r
+ }\r
+ s->substate_context_map = BROTLI_STATE_CONTEXT_MAP_NONE;\r
+ return BROTLI_DECODER_SUCCESS;\r
+ }\r
+ default:\r
+ return\r
+ BROTLI_FAILURE(BROTLI_DECODER_ERROR_UNREACHABLE);\r
+ }\r
+}\r
+\r
+/* Decodes a command or literal and updates block type ringbuffer.\r
+ Reads 3..54 bits. */\r
+static BROTLI_INLINE BROTLI_BOOL DecodeBlockTypeAndLength(\r
+ int safe, BrotliDecoderState* s, int tree_type) {\r
+ uint32_t max_block_type = s->num_block_types[tree_type];\r
+ const HuffmanCode* type_tree = &s->block_type_trees[\r
+ tree_type * BROTLI_HUFFMAN_MAX_SIZE_258];\r
+ const HuffmanCode* len_tree = &s->block_len_trees[\r
+ tree_type * BROTLI_HUFFMAN_MAX_SIZE_26];\r
+ BrotliBitReader* br = &s->br;\r
+ uint32_t* ringbuffer = &s->block_type_rb[tree_type * 2];\r
+ uint32_t block_type;\r
+\r
+ /* Read 0..15 + 3..39 bits */\r
+ if (!safe) {\r
+ block_type = ReadSymbol(type_tree, br);\r
+ s->block_length[tree_type] = ReadBlockLength(len_tree, br);\r
+ } else {\r
+ BrotliBitReaderState memento;\r
+ BrotliBitReaderSaveState(br, &memento);\r
+ if (!SafeReadSymbol(type_tree, br, &block_type)) return BROTLI_FALSE;\r
+ if (!SafeReadBlockLength(s, &s->block_length[tree_type], len_tree, br)) {\r
+ s->substate_read_block_length = BROTLI_STATE_READ_BLOCK_LENGTH_NONE;\r
+ BrotliBitReaderRestoreState(br, &memento);\r
+ return BROTLI_FALSE;\r
+ }\r
+ }\r
+\r
+ if (block_type == 1) {\r
+ block_type = ringbuffer[1] + 1;\r
+ } else if (block_type == 0) {\r
+ block_type = ringbuffer[0];\r
+ } else {\r
+ block_type -= 2;\r
+ }\r
+ if (block_type >= max_block_type) {\r
+ block_type -= max_block_type;\r
+ }\r
+ ringbuffer[0] = ringbuffer[1];\r
+ ringbuffer[1] = block_type;\r
+ return BROTLI_TRUE;\r
+}\r
+\r
+static BROTLI_INLINE void DetectTrivialLiteralBlockTypes(\r
+ BrotliDecoderState* s) {\r
+ size_t i;\r
+ for (i = 0; i < 8; ++i) s->trivial_literal_contexts[i] = 0;\r
+ for (i = 0; i < s->num_block_types[0]; i++) {\r
+ size_t offset = i << BROTLI_LITERAL_CONTEXT_BITS;\r
+ size_t error = 0;\r
+ size_t sample = s->context_map[offset];\r
+ size_t j;\r
+ for (j = 0; j < (1u << BROTLI_LITERAL_CONTEXT_BITS);) {\r
+ BROTLI_REPEAT(4, error |= s->context_map[offset + j++] ^ sample;)\r
+ }\r
+ if (error == 0) {\r
+ s->trivial_literal_contexts[i >> 5] |= 1u << (i & 31);\r
+ }\r
+ }\r
+}\r
+\r
+static BROTLI_INLINE void PrepareLiteralDecoding(BrotliDecoderState* s) {\r
+ uint8_t context_mode;\r
+ size_t trivial;\r
+ uint32_t block_type = s->block_type_rb[1];\r
+ uint32_t context_offset = block_type << BROTLI_LITERAL_CONTEXT_BITS;\r
+ s->context_map_slice = s->context_map + context_offset;\r
+ trivial = s->trivial_literal_contexts[block_type >> 5];\r
+ s->trivial_literal_context = (trivial >> (block_type & 31)) & 1;\r
+ s->literal_htree = s->literal_hgroup.htrees[s->context_map_slice[0]];\r
+ context_mode = s->context_modes[block_type];\r
+ s->context_lookup1 = &kContextLookup[kContextLookupOffsets[context_mode]];\r
+ s->context_lookup2 = &kContextLookup[kContextLookupOffsets[context_mode + 1]];\r
+}\r
+\r
+/* Decodes the block type and updates the state for literal context.\r
+ Reads 3..54 bits. */\r
+static BROTLI_INLINE BROTLI_BOOL DecodeLiteralBlockSwitchInternal(\r
+ int safe, BrotliDecoderState* s) {\r
+ if (!DecodeBlockTypeAndLength(safe, s, 0)) {\r
+ return BROTLI_FALSE;\r
+ }\r
+ PrepareLiteralDecoding(s);\r
+ return BROTLI_TRUE;\r
+}\r
+\r
+static void BROTLI_NOINLINE DecodeLiteralBlockSwitch(BrotliDecoderState* s) {\r
+ DecodeLiteralBlockSwitchInternal(0, s);\r
+}\r
+\r
+static BROTLI_BOOL BROTLI_NOINLINE SafeDecodeLiteralBlockSwitch(\r
+ BrotliDecoderState* s) {\r
+ return DecodeLiteralBlockSwitchInternal(1, s);\r
+}\r
+\r
+/* Block switch for insert/copy length.\r
+ Reads 3..54 bits. */\r
+static BROTLI_INLINE BROTLI_BOOL DecodeCommandBlockSwitchInternal(\r
+ int safe, BrotliDecoderState* s) {\r
+ if (!DecodeBlockTypeAndLength(safe, s, 1)) {\r
+ return BROTLI_FALSE;\r
+ }\r
+ s->htree_command = s->insert_copy_hgroup.htrees[s->block_type_rb[3]];\r
+ return BROTLI_TRUE;\r
+}\r
+\r
+static void BROTLI_NOINLINE DecodeCommandBlockSwitch(BrotliDecoderState* s) {\r
+ DecodeCommandBlockSwitchInternal(0, s);\r
+}\r
+static BROTLI_BOOL BROTLI_NOINLINE SafeDecodeCommandBlockSwitch(\r
+ BrotliDecoderState* s) {\r
+ return DecodeCommandBlockSwitchInternal(1, s);\r
+}\r
+\r
+/* Block switch for distance codes.\r
+ Reads 3..54 bits. */\r
+static BROTLI_INLINE BROTLI_BOOL DecodeDistanceBlockSwitchInternal(\r
+ int safe, BrotliDecoderState* s) {\r
+ if (!DecodeBlockTypeAndLength(safe, s, 2)) {\r
+ return BROTLI_FALSE;\r
+ }\r
+ s->dist_context_map_slice = s->dist_context_map +\r
+ (s->block_type_rb[5] << BROTLI_DISTANCE_CONTEXT_BITS);\r
+ s->dist_htree_index = s->dist_context_map_slice[s->distance_context];\r
+ return BROTLI_TRUE;\r
+}\r
+\r
+static void BROTLI_NOINLINE DecodeDistanceBlockSwitch(BrotliDecoderState* s) {\r
+ DecodeDistanceBlockSwitchInternal(0, s);\r
+}\r
+\r
+static BROTLI_BOOL BROTLI_NOINLINE SafeDecodeDistanceBlockSwitch(\r
+ BrotliDecoderState* s) {\r
+ return DecodeDistanceBlockSwitchInternal(1, s);\r
+}\r
+\r
+static size_t UnwrittenBytes(const BrotliDecoderState* s, BROTLI_BOOL wrap) {\r
+ size_t pos = wrap && s->pos > s->ringbuffer_size ?\r
+ (size_t)s->ringbuffer_size : (size_t)(s->pos);\r
+ size_t partial_pos_rb = (s->rb_roundtrips * (size_t)s->ringbuffer_size) + pos;\r
+ return partial_pos_rb - s->partial_pos_out;\r
+}\r
+\r
+static BrotliDecoderErrorCode BROTLI_NOINLINE WriteRingBuffer(\r
+ BrotliDecoderState* s, size_t* available_out, uint8_t** next_out,\r
+ size_t* total_out) {\r
+ uint8_t* start =\r
+ s->ringbuffer + (s->partial_pos_out & (size_t)s->ringbuffer_mask);\r
+ size_t to_write = UnwrittenBytes(s, BROTLI_TRUE);\r
+ size_t num_written = *available_out;\r
+ if (num_written > to_write) {\r
+ num_written = to_write;\r
+ }\r
+ if (s->meta_block_remaining_len < 0) {\r
+ return BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_BLOCK_LENGTH_1);\r
+ }\r
+ memcpy(*next_out, start, num_written);\r
+ *next_out += num_written;\r
+ *available_out -= num_written;\r
+ BROTLI_LOG_UINT(to_write);\r
+ BROTLI_LOG_UINT(num_written);\r
+ s->partial_pos_out += num_written;\r
+ if (total_out) *total_out = s->partial_pos_out;\r
+ if (num_written < to_write) {\r
+ return BROTLI_DECODER_NEEDS_MORE_OUTPUT;\r
+ }\r
+\r
+ if (s->pos >= s->ringbuffer_size) {\r
+ s->pos -= s->ringbuffer_size;\r
+ s->rb_roundtrips++;\r
+ }\r
+ return BROTLI_DECODER_SUCCESS;\r
+}\r
+\r
+/* Allocates ringbuffer.\r
+\r
+ s->ringbuffer_size MUST be updated by BrotliCalculateRingBufferSize before\r
+ this function is called.\r
+\r
+ Last two bytes of ringbuffer are initialized to 0, so context calculation\r
+ could be done uniformly for the first two and all other positions.\r
+\r
+ Custom dictionary, if any, is copied to the end of ringbuffer.\r
+*/\r
+static BROTLI_BOOL BROTLI_NOINLINE BrotliAllocateRingBuffer(\r
+ BrotliDecoderState* s) {\r
+ /* We need the slack region for the following reasons:\r
+ - doing up to two 16-byte copies for fast backward copying\r
+ - inserting transformed dictionary word (5 prefix + 24 base + 8 suffix) */\r
+ static const int kRingBufferWriteAheadSlack = 42;\r
+ s->ringbuffer = (uint8_t*)BROTLI_ALLOC(s, (size_t)(s->ringbuffer_size +\r
+ kRingBufferWriteAheadSlack));\r
+ if (s->ringbuffer == 0) {\r
+ return BROTLI_FALSE;\r
+ }\r
+\r
+ s->ringbuffer_end = s->ringbuffer + s->ringbuffer_size;\r
+\r
+ s->ringbuffer[s->ringbuffer_size - 2] = 0;\r
+ s->ringbuffer[s->ringbuffer_size - 1] = 0;\r
+\r
+ if (s->custom_dict) {\r
+ memcpy(&s->ringbuffer[(-s->custom_dict_size) & s->ringbuffer_mask],\r
+ s->custom_dict, (size_t)s->custom_dict_size);\r
+ }\r
+\r
+ return BROTLI_TRUE;\r
+}\r
+\r
+static BrotliDecoderErrorCode BROTLI_NOINLINE CopyUncompressedBlockToOutput(\r
+ size_t* available_out, uint8_t** next_out, size_t* total_out,\r
+ BrotliDecoderState* s) {\r
+ /* TODO: avoid allocation for single uncompressed block. */\r
+ if (!s->ringbuffer && !BrotliAllocateRingBuffer(s)) {\r
+ return BROTLI_FAILURE(BROTLI_DECODER_ERROR_ALLOC_RING_BUFFER_1);\r
+ }\r
+\r
+ /* State machine */\r
+ for (;;) {\r
+ switch (s->substate_uncompressed) {\r
+ case BROTLI_STATE_UNCOMPRESSED_NONE: {\r
+ int nbytes = (int)BrotliGetRemainingBytes(&s->br);\r
+ if (nbytes > s->meta_block_remaining_len) {\r
+ nbytes = s->meta_block_remaining_len;\r
+ }\r
+ if (s->pos + nbytes > s->ringbuffer_size) {\r
+ nbytes = s->ringbuffer_size - s->pos;\r
+ }\r
+ /* Copy remaining bytes from s->br.buf_ to ringbuffer. */\r
+ BrotliCopyBytes(&s->ringbuffer[s->pos], &s->br, (size_t)nbytes);\r
+ s->pos += nbytes;\r
+ s->meta_block_remaining_len -= nbytes;\r
+ if (s->pos < s->ringbuffer_size) {\r
+ if (s->meta_block_remaining_len == 0) {\r
+ return BROTLI_DECODER_SUCCESS;\r
+ }\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ s->substate_uncompressed = BROTLI_STATE_UNCOMPRESSED_WRITE;\r
+ /* No break, continue to next state */\r
+ }\r
+ case BROTLI_STATE_UNCOMPRESSED_WRITE: {\r
+ BrotliDecoderErrorCode result =\r
+ WriteRingBuffer(s, available_out, next_out, total_out);\r
+ if (result != BROTLI_DECODER_SUCCESS) {\r
+ return result;\r
+ }\r
+ s->max_distance = s->max_backward_distance;\r
+ s->substate_uncompressed = BROTLI_STATE_UNCOMPRESSED_NONE;\r
+ break;\r
+ }\r
+ }\r
+ }\r
+ BROTLI_DCHECK(0); /* Unreachable */\r
+}\r
+\r
+BROTLI_BOOL BrotliDecompressedSize(size_t encoded_size,\r
+ const uint8_t* encoded_buffer,\r
+ size_t* decoded_size) {\r
+ size_t total_size = 0;\r
+ BrotliDecoderState s;\r
+ BrotliBitReader* br;\r
+ BrotliDecoderStateInit(&s);\r
+ br = &s.br;\r
+ *decoded_size = 0;\r
+ br->next_in = encoded_buffer;\r
+ br->avail_in = encoded_size;\r
+ if (!BrotliWarmupBitReader(br)) return BROTLI_FALSE;\r
+ DecodeWindowBits(br);\r
+ while (1) {\r
+ size_t block_size;\r
+ if (DecodeMetaBlockLength(&s, br) != BROTLI_DECODER_SUCCESS) {\r
+ return BROTLI_FALSE;\r
+ }\r
+ block_size = (size_t)s.meta_block_remaining_len;\r
+ if (!s.is_metadata) {\r
+ if ((block_size + total_size) < total_size) return BROTLI_FALSE;\r
+ total_size += block_size;\r
+ }\r
+ if (s.is_last_metablock) {\r
+ *decoded_size = total_size;\r
+ return BROTLI_TRUE;\r
+ }\r
+ if (!s.is_uncompressed && !s.is_metadata) return BROTLI_FALSE;\r
+ if (!BrotliJumpToByteBoundary(br)) return BROTLI_FALSE;\r
+ BrotliBitReaderUnload(br);\r
+ if (br->avail_in < block_size) return BROTLI_FALSE;\r
+ br->avail_in -= block_size;\r
+ br->next_in += block_size;\r
+ if (!BrotliWarmupBitReader(br)) return BROTLI_FALSE;\r
+ }\r
+}\r
+\r
+/* Calculates the smallest feasible ring buffer.\r
+\r
+ If we know the data size is small, do not allocate more ringbuffer\r
+ size than needed to reduce memory usage.\r
+\r
+ When this method is called, metablock size and flags MUST be decoded.\r
+*/\r
+static void BROTLI_NOINLINE BrotliCalculateRingBufferSize(\r
+ BrotliDecoderState* s, BrotliBitReader* br) {\r
+ BROTLI_BOOL is_last = TO_BROTLI_BOOL(s->is_last_metablock);\r
+ int window_size = 1 << s->window_bits;\r
+ s->ringbuffer_size = window_size;\r
+\r
+ if (s->is_uncompressed) {\r
+ int next_block_header =\r
+ BrotliPeekByte(br, (size_t)s->meta_block_remaining_len);\r
+ if (next_block_header != -1) { /* Peek succeeded */\r
+ if ((next_block_header & 3) == 3) { /* ISLAST and ISEMPTY */\r
+ is_last = BROTLI_TRUE;\r
+ }\r
+ }\r
+ }\r
+\r
+ /* We need at least 2 bytes of ring buffer size to get the last two\r
+ bytes for context from there */\r
+ if (is_last) {\r
+ int min_size_x2 = (s->meta_block_remaining_len + s->custom_dict_size) * 2;\r
+ while (s->ringbuffer_size >= min_size_x2 && s->ringbuffer_size > 32) {\r
+ s->ringbuffer_size >>= 1;\r
+ }\r
+ }\r
+\r
+ s->ringbuffer_mask = s->ringbuffer_size - 1;\r
+}\r
+\r
+/* Reads 1..256 2-bit context modes. */\r
+static BrotliDecoderErrorCode ReadContextModes(BrotliDecoderState* s) {\r
+ BrotliBitReader* br = &s->br;\r
+ int i = s->loop_counter;\r
+\r
+ while (i < (int)s->num_block_types[0]) {\r
+ uint32_t bits;\r
+ if (!BrotliSafeReadBits(br, 2, &bits)) {\r
+ s->loop_counter = i;\r
+ return BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ }\r
+ s->context_modes[i] = (uint8_t)(bits << 1);\r
+ BROTLI_LOG_ARRAY_INDEX(s->context_modes, i);\r
+ i++;\r
+ }\r
+ return BROTLI_DECODER_SUCCESS;\r
+}\r
+\r
+static BROTLI_INLINE void TakeDistanceFromRingBuffer(BrotliDecoderState* s) {\r
+ if (s->distance_code == 0) {\r
+ --s->dist_rb_idx;\r
+ s->distance_code = s->dist_rb[s->dist_rb_idx & 3];\r
+ } else {\r
+ int distance_code = s->distance_code << 1;\r
+ /* kDistanceShortCodeIndexOffset has 2-bit values from LSB: */\r
+ /* 3, 2, 1, 0, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2 */\r
+ const uint32_t kDistanceShortCodeIndexOffset = 0xaaafff1b;\r
+ /* kDistanceShortCodeValueOffset has 2-bit values from LSB: */\r
+ /*-0, 0,-0, 0,-1, 1,-2, 2,-3, 3,-1, 1,-2, 2,-3, 3 */\r
+ const uint32_t kDistanceShortCodeValueOffset = 0xfa5fa500;\r
+ int v = (s->dist_rb_idx +\r
+ (int)(kDistanceShortCodeIndexOffset >> distance_code)) & 0x3;\r
+ s->distance_code = s->dist_rb[v];\r
+ v = (int)(kDistanceShortCodeValueOffset >> distance_code) & 0x3;\r
+ if ((distance_code & 0x3) != 0) {\r
+ s->distance_code += v;\r
+ } else {\r
+ s->distance_code -= v;\r
+ if (s->distance_code <= 0) {\r
+ /* A huge distance will cause a BROTLI_FAILURE() soon. */\r
+ /* This is a little faster than failing here. */\r
+ s->distance_code = 0x0fffffff;\r
+ }\r
+ }\r
+ }\r
+}\r
+\r
+static BROTLI_INLINE BROTLI_BOOL SafeReadBits(\r
+ BrotliBitReader* const br, uint32_t n_bits, uint32_t* val) {\r
+ if (n_bits != 0) {\r
+ return BrotliSafeReadBits(br, n_bits, val);\r
+ } else {\r
+ *val = 0;\r
+ return BROTLI_TRUE;\r
+ }\r
+}\r
+\r
+/* Precondition: s->distance_code < 0 */\r
+static BROTLI_INLINE BROTLI_BOOL ReadDistanceInternal(\r
+ int safe, BrotliDecoderState* s, BrotliBitReader* br) {\r
+ int distval;\r
+ BrotliBitReaderState memento;\r
+ HuffmanCode* distance_tree = s->distance_hgroup.htrees[s->dist_htree_index];\r
+ if (!safe) {\r
+ s->distance_code = (int)ReadSymbol(distance_tree, br);\r
+ } else {\r
+ uint32_t code;\r
+ BrotliBitReaderSaveState(br, &memento);\r
+ if (!SafeReadSymbol(distance_tree, br, &code)) {\r
+ return BROTLI_FALSE;\r
+ }\r
+ s->distance_code = (int)code;\r
+ }\r
+ /* Convert the distance code to the actual distance by possibly */\r
+ /* looking up past distances from the s->ringbuffer. */\r
+ if ((s->distance_code & ~0xf) == 0) {\r
+ TakeDistanceFromRingBuffer(s);\r
+ --s->block_length[2];\r
+ return BROTLI_TRUE;\r
+ }\r
+ distval = s->distance_code - (int)s->num_direct_distance_codes;\r
+ if (distval >= 0) {\r
+ uint32_t nbits;\r
+ int postfix;\r
+ int offset;\r
+ if (!safe && (s->distance_postfix_bits == 0)) {\r
+ nbits = ((uint32_t)distval >> 1) + 1;\r
+ offset = ((2 + (distval & 1)) << nbits) - 4;\r
+ s->distance_code = (int)s->num_direct_distance_codes + offset +\r
+ (int)BrotliReadBits(br, nbits);\r
+ } else {\r
+ /* This branch also works well when s->distance_postfix_bits == 0 */\r
+ uint32_t bits;\r
+ postfix = distval & s->distance_postfix_mask;\r
+ distval >>= s->distance_postfix_bits;\r
+ nbits = ((uint32_t)distval >> 1) + 1;\r
+ if (safe) {\r
+ if (!SafeReadBits(br, nbits, &bits)) {\r
+ s->distance_code = -1; /* Restore precondition. */\r
+ BrotliBitReaderRestoreState(br, &memento);\r
+ return BROTLI_FALSE;\r
+ }\r
+ } else {\r
+ bits = BrotliReadBits(br, nbits);\r
+ }\r
+ offset = ((2 + (distval & 1)) << nbits) - 4;\r
+ s->distance_code = (int)s->num_direct_distance_codes +\r
+ ((offset + (int)bits) << s->distance_postfix_bits) + postfix;\r
+ }\r
+ }\r
+ s->distance_code = s->distance_code - BROTLI_NUM_DISTANCE_SHORT_CODES + 1;\r
+ --s->block_length[2];\r
+ return BROTLI_TRUE;\r
+}\r
+\r
+static BROTLI_INLINE void ReadDistance(\r
+ BrotliDecoderState* s, BrotliBitReader* br) {\r
+ ReadDistanceInternal(0, s, br);\r
+}\r
+\r
+static BROTLI_INLINE BROTLI_BOOL SafeReadDistance(\r
+ BrotliDecoderState* s, BrotliBitReader* br) {\r
+ return ReadDistanceInternal(1, s, br);\r
+}\r
+\r
+static BROTLI_INLINE BROTLI_BOOL ReadCommandInternal(\r
+ int safe, BrotliDecoderState* s, BrotliBitReader* br, int* insert_length) {\r
+ uint32_t cmd_code;\r
+ uint32_t insert_len_extra = 0;\r
+ uint32_t copy_length;\r
+ CmdLutElement v;\r
+ BrotliBitReaderState memento;\r
+ if (!safe) {\r
+ cmd_code = ReadSymbol(s->htree_command, br);\r
+ } else {\r
+ BrotliBitReaderSaveState(br, &memento);\r
+ if (!SafeReadSymbol(s->htree_command, br, &cmd_code)) {\r
+ return BROTLI_FALSE;\r
+ }\r
+ }\r
+ v = kCmdLut[cmd_code];\r
+ s->distance_code = v.distance_code;\r
+ s->distance_context = v.context;\r
+ s->dist_htree_index = s->dist_context_map_slice[s->distance_context];\r
+ *insert_length = v.insert_len_offset;\r
+ if (!safe) {\r
+ if (PREDICT_FALSE(v.insert_len_extra_bits != 0)) {\r
+ insert_len_extra = BrotliReadBits(br, v.insert_len_extra_bits);\r
+ }\r
+ copy_length = BrotliReadBits(br, v.copy_len_extra_bits);\r
+ } else {\r
+ if (!SafeReadBits(br, v.insert_len_extra_bits, &insert_len_extra) ||\r
+ !SafeReadBits(br, v.copy_len_extra_bits, ©_length)) {\r
+ BrotliBitReaderRestoreState(br, &memento);\r
+ return BROTLI_FALSE;\r
+ }\r
+ }\r
+ s->copy_length = (int)copy_length + v.copy_len_offset;\r
+ --s->block_length[1];\r
+ *insert_length += (int)insert_len_extra;\r
+ return BROTLI_TRUE;\r
+}\r
+\r
+static BROTLI_INLINE void ReadCommand(\r
+ BrotliDecoderState* s, BrotliBitReader* br, int* insert_length) {\r
+ ReadCommandInternal(0, s, br, insert_length);\r
+}\r
+\r
+static BROTLI_INLINE BROTLI_BOOL SafeReadCommand(\r
+ BrotliDecoderState* s, BrotliBitReader* br, int* insert_length) {\r
+ return ReadCommandInternal(1, s, br, insert_length);\r
+}\r
+\r
+static BROTLI_INLINE BROTLI_BOOL CheckInputAmount(\r
+ int safe, BrotliBitReader* const br, size_t num) {\r
+ if (safe) {\r
+ return BROTLI_TRUE;\r
+ }\r
+ return BrotliCheckInputAmount(br, num);\r
+}\r
+\r
+#define BROTLI_SAFE(METHOD) \\r
+ { \\r
+ if (safe) { \\r
+ if (!Safe##METHOD) { \\r
+ result = BROTLI_DECODER_NEEDS_MORE_INPUT; \\r
+ goto saveStateAndReturn; \\r
+ } \\r
+ } else { \\r
+ METHOD; \\r
+ } \\r
+ }\r
+\r
+static BROTLI_INLINE BrotliDecoderErrorCode ProcessCommandsInternal(\r
+ int safe, BrotliDecoderState* s) {\r
+ int pos = s->pos;\r
+ int i = s->loop_counter;\r
+ BrotliDecoderErrorCode result = BROTLI_DECODER_SUCCESS;\r
+ BrotliBitReader* br = &s->br;\r
+\r
+ if (!CheckInputAmount(safe, br, 28)) {\r
+ result = BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ goto saveStateAndReturn;\r
+ }\r
+ if (!safe) {\r
+ BROTLI_UNUSED(BrotliWarmupBitReader(br));\r
+ }\r
+\r
+ /* Jump into state machine. */\r
+ if (s->state == BROTLI_STATE_COMMAND_BEGIN) {\r
+ goto CommandBegin;\r
+ } else if (s->state == BROTLI_STATE_COMMAND_INNER) {\r
+ goto CommandInner;\r
+ } else if (s->state == BROTLI_STATE_COMMAND_POST_DECODE_LITERALS) {\r
+ goto CommandPostDecodeLiterals;\r
+ } else if (s->state == BROTLI_STATE_COMMAND_POST_WRAP_COPY) {\r
+ goto CommandPostWrapCopy;\r
+ } else {\r
+ return BROTLI_FAILURE(BROTLI_DECODER_ERROR_UNREACHABLE);\r
+ }\r
+\r
+CommandBegin:\r
+ if (safe) {\r
+ s->state = BROTLI_STATE_COMMAND_BEGIN;\r
+ }\r
+ if (!CheckInputAmount(safe, br, 28)) { /* 156 bits + 7 bytes */\r
+ s->state = BROTLI_STATE_COMMAND_BEGIN;\r
+ result = BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ goto saveStateAndReturn;\r
+ }\r
+ if (PREDICT_FALSE(s->block_length[1] == 0)) {\r
+ BROTLI_SAFE(DecodeCommandBlockSwitch(s));\r
+ goto CommandBegin;\r
+ }\r
+ /* Read the insert/copy length in the command */\r
+ BROTLI_SAFE(ReadCommand(s, br, &i));\r
+ BROTLI_LOG(("[ProcessCommandsInternal] pos = %d insert = %d copy = %d\n",\r
+ pos, i, s->copy_length));\r
+ if (i == 0) {\r
+ goto CommandPostDecodeLiterals;\r
+ }\r
+ s->meta_block_remaining_len -= i;\r
+\r
+CommandInner:\r
+ if (safe) {\r
+ s->state = BROTLI_STATE_COMMAND_INNER;\r
+ }\r
+ /* Read the literals in the command */\r
+ if (s->trivial_literal_context) {\r
+ uint32_t bits;\r
+ uint32_t value;\r
+ PreloadSymbol(safe, s->literal_htree, br, &bits, &value);\r
+ do {\r
+ if (!CheckInputAmount(safe, br, 28)) { /* 162 bits + 7 bytes */\r
+ s->state = BROTLI_STATE_COMMAND_INNER;\r
+ result = BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ goto saveStateAndReturn;\r
+ }\r
+ if (PREDICT_FALSE(s->block_length[0] == 0)) {\r
+ BROTLI_SAFE(DecodeLiteralBlockSwitch(s));\r
+ PreloadSymbol(safe, s->literal_htree, br, &bits, &value);\r
+ if (!s->trivial_literal_context) goto CommandInner;\r
+ }\r
+ if (!safe) {\r
+ s->ringbuffer[pos] =\r
+ (uint8_t)ReadPreloadedSymbol(s->literal_htree, br, &bits, &value);\r
+ } else {\r
+ uint32_t literal;\r
+ if (!SafeReadSymbol(s->literal_htree, br, &literal)) {\r
+ result = BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ goto saveStateAndReturn;\r
+ }\r
+ s->ringbuffer[pos] = (uint8_t)literal;\r
+ }\r
+ --s->block_length[0];\r
+ BROTLI_LOG_ARRAY_INDEX(s->ringbuffer, pos);\r
+ ++pos;\r
+ if (PREDICT_FALSE(pos == s->ringbuffer_size)) {\r
+ s->state = BROTLI_STATE_COMMAND_INNER_WRITE;\r
+ --i;\r
+ goto saveStateAndReturn;\r
+ }\r
+ } while (--i != 0);\r
+ } else {\r
+ uint8_t p1 = s->ringbuffer[(pos - 1) & s->ringbuffer_mask];\r
+ uint8_t p2 = s->ringbuffer[(pos - 2) & s->ringbuffer_mask];\r
+ do {\r
+ const HuffmanCode* hc;\r
+ uint8_t context;\r
+ if (!CheckInputAmount(safe, br, 28)) { /* 162 bits + 7 bytes */\r
+ s->state = BROTLI_STATE_COMMAND_INNER;\r
+ result = BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ goto saveStateAndReturn;\r
+ }\r
+ if (PREDICT_FALSE(s->block_length[0] == 0)) {\r
+ BROTLI_SAFE(DecodeLiteralBlockSwitch(s));\r
+ if (s->trivial_literal_context) goto CommandInner;\r
+ }\r
+ context = s->context_lookup1[p1] | s->context_lookup2[p2];\r
+ BROTLI_LOG_UINT(context);\r
+ hc = s->literal_hgroup.htrees[s->context_map_slice[context]];\r
+ p2 = p1;\r
+ if (!safe) {\r
+ p1 = (uint8_t)ReadSymbol(hc, br);\r
+ } else {\r
+ uint32_t literal;\r
+ if (!SafeReadSymbol(hc, br, &literal)) {\r
+ result = BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ goto saveStateAndReturn;\r
+ }\r
+ p1 = (uint8_t)literal;\r
+ }\r
+ s->ringbuffer[pos] = p1;\r
+ --s->block_length[0];\r
+ BROTLI_LOG_UINT(s->context_map_slice[context]);\r
+ BROTLI_LOG_ARRAY_INDEX(s->ringbuffer, pos & s->ringbuffer_mask);\r
+ ++pos;\r
+ if (PREDICT_FALSE(pos == s->ringbuffer_size)) {\r
+ s->state = BROTLI_STATE_COMMAND_INNER_WRITE;\r
+ --i;\r
+ goto saveStateAndReturn;\r
+ }\r
+ } while (--i != 0);\r
+ }\r
+ BROTLI_LOG_UINT(s->meta_block_remaining_len);\r
+ if (PREDICT_FALSE(s->meta_block_remaining_len <= 0)) {\r
+ s->state = BROTLI_STATE_METABLOCK_DONE;\r
+ goto saveStateAndReturn;\r
+ }\r
+\r
+CommandPostDecodeLiterals:\r
+ if (safe) {\r
+ s->state = BROTLI_STATE_COMMAND_POST_DECODE_LITERALS;\r
+ }\r
+ if (s->distance_code >= 0) {\r
+ --s->dist_rb_idx;\r
+ s->distance_code = s->dist_rb[s->dist_rb_idx & 3];\r
+ goto postReadDistance; /* We already have the implicit distance */\r
+ }\r
+ /* Read distance code in the command, unless it was implicitly zero. */\r
+ if (PREDICT_FALSE(s->block_length[2] == 0)) {\r
+ BROTLI_SAFE(DecodeDistanceBlockSwitch(s));\r
+ }\r
+ BROTLI_SAFE(ReadDistance(s, br));\r
+postReadDistance:\r
+ BROTLI_LOG(("[ProcessCommandsInternal] pos = %d distance = %d\n",\r
+ pos, s->distance_code));\r
+ if (s->max_distance != s->max_backward_distance) {\r
+ if (pos < s->max_backward_distance_minus_custom_dict_size) {\r
+ s->max_distance = pos + s->custom_dict_size;\r
+ } else {\r
+ s->max_distance = s->max_backward_distance;\r
+ }\r
+ }\r
+ i = s->copy_length;\r
+ /* Apply copy of LZ77 back-reference, or static dictionary reference if\r
+ the distance is larger than the max LZ77 distance */\r
+ if (s->distance_code > s->max_distance) {\r
+ if (i >= kBrotliMinDictionaryWordLength &&\r
+ i <= kBrotliMaxDictionaryWordLength) {\r
+ int offset = (int)kBrotliDictionaryOffsetsByLength[i];\r
+ int word_id = s->distance_code - s->max_distance - 1;\r
+ uint32_t shift = kBrotliDictionarySizeBitsByLength[i];\r
+ int mask = (int)BitMask(shift);\r
+ int word_idx = word_id & mask;\r
+ int transform_idx = word_id >> shift;\r
+ offset += word_idx * i;\r
+ if (transform_idx < kNumTransforms) {\r
+ const uint8_t* word = &kBrotliDictionary[offset];\r
+ int len = i;\r
+ if (transform_idx == 0) {\r
+ memcpy(&s->ringbuffer[pos], word, (size_t)len);\r
+ } else {\r
+ len = TransformDictionaryWord(\r
+ &s->ringbuffer[pos], word, len, transform_idx);\r
+ }\r
+ pos += len;\r
+ s->meta_block_remaining_len -= len;\r
+ if (pos >= s->ringbuffer_size) {\r
+ /*s->partial_pos_rb += (size_t)s->ringbuffer_size;*/\r
+ s->state = BROTLI_STATE_COMMAND_POST_WRITE_1;\r
+ goto saveStateAndReturn;\r
+ }\r
+ } else {\r
+ BROTLI_LOG(("Invalid backward reference. pos: %d distance: %d "\r
+ "len: %d bytes left: %d\n",\r
+ pos, s->distance_code, i, s->meta_block_remaining_len));\r
+ return BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_TRANSFORM);\r
+ }\r
+ } else {\r
+ BROTLI_LOG(("Invalid backward reference. pos: %d distance: %d "\r
+ "len: %d bytes left: %d\n",\r
+ pos, s->distance_code, i, s->meta_block_remaining_len));\r
+ return BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_DICTIONARY);\r
+ }\r
+ } else {\r
+ int src_start = (pos - s->distance_code) & s->ringbuffer_mask;\r
+ uint8_t* copy_dst = &s->ringbuffer[pos];\r
+ uint8_t* copy_src = &s->ringbuffer[src_start];\r
+ int dst_end = pos + i;\r
+ int src_end = src_start + i;\r
+ /* update the recent distances cache */\r
+ s->dist_rb[s->dist_rb_idx & 3] = s->distance_code;\r
+ ++s->dist_rb_idx;\r
+ s->meta_block_remaining_len -= i;\r
+ /* There are 32+ bytes of slack in the ringbuffer allocation.\r
+ Also, we have 16 short codes, that make these 16 bytes irrelevant\r
+ in the ringbuffer. Let's copy over them as a first guess.\r
+ */\r
+ memmove16(copy_dst, copy_src);\r
+ if (src_end > pos && dst_end > src_start) {\r
+ /* Regions intersect. */\r
+ goto CommandPostWrapCopy;\r
+ }\r
+ if (dst_end >= s->ringbuffer_size || src_end >= s->ringbuffer_size) {\r
+ /* At least one region wraps. */\r
+ goto CommandPostWrapCopy;\r
+ }\r
+ pos += i;\r
+ if (i > 16) {\r
+ if (i > 32) {\r
+ memcpy(copy_dst + 16, copy_src + 16, (size_t)(i - 16));\r
+ } else {\r
+ /* This branch covers about 45% cases.\r
+ Fixed size short copy allows more compiler optimizations. */\r
+ memmove16(copy_dst + 16, copy_src + 16);\r
+ }\r
+ }\r
+ }\r
+ BROTLI_LOG_UINT(s->meta_block_remaining_len);\r
+ if (s->meta_block_remaining_len <= 0) {\r
+ /* Next metablock, if any */\r
+ s->state = BROTLI_STATE_METABLOCK_DONE;\r
+ goto saveStateAndReturn;\r
+ } else {\r
+ goto CommandBegin;\r
+ }\r
+CommandPostWrapCopy:\r
+ {\r
+ int wrap_guard = s->ringbuffer_size - pos;\r
+ while (--i >= 0) {\r
+ s->ringbuffer[pos] =\r
+ s->ringbuffer[(pos - s->distance_code) & s->ringbuffer_mask];\r
+ ++pos;\r
+ if (PREDICT_FALSE(--wrap_guard == 0)) {\r
+ s->state = BROTLI_STATE_COMMAND_POST_WRITE_2;\r
+ goto saveStateAndReturn;\r
+ }\r
+ }\r
+ }\r
+ if (s->meta_block_remaining_len <= 0) {\r
+ /* Next metablock, if any */\r
+ s->state = BROTLI_STATE_METABLOCK_DONE;\r
+ goto saveStateAndReturn;\r
+ } else {\r
+ goto CommandBegin;\r
+ }\r
+\r
+saveStateAndReturn:\r
+ s->pos = pos;\r
+ s->loop_counter = i;\r
+ return result;\r
+}\r
+\r
+#undef BROTLI_SAFE\r
+\r
+static BROTLI_NOINLINE BrotliDecoderErrorCode ProcessCommands(\r
+ BrotliDecoderState* s) {\r
+ return ProcessCommandsInternal(0, s);\r
+}\r
+\r
+static BROTLI_NOINLINE BrotliDecoderErrorCode SafeProcessCommands(\r
+ BrotliDecoderState* s) {\r
+ return ProcessCommandsInternal(1, s);\r
+}\r
+\r
+BrotliDecoderResult BrotliDecoderDecompress(\r
+ size_t encoded_size, const uint8_t* encoded_buffer, size_t* decoded_size,\r
+ uint8_t* decoded_buffer) {\r
+ BrotliDecoderState s;\r
+ BrotliDecoderResult result;\r
+ size_t total_out = 0;\r
+ size_t available_in = encoded_size;\r
+ const uint8_t* next_in = encoded_buffer;\r
+ size_t available_out = *decoded_size;\r
+ uint8_t* next_out = decoded_buffer;\r
+ BrotliDecoderStateInit(&s);\r
+ result = BrotliDecoderDecompressStream(\r
+ &s, &available_in, &next_in, &available_out, &next_out, &total_out);\r
+ *decoded_size = total_out;\r
+ BrotliDecoderStateCleanup(&s);\r
+ if (result != BROTLI_DECODER_RESULT_SUCCESS) {\r
+ result = BROTLI_DECODER_RESULT_ERROR;\r
+ }\r
+ return result;\r
+}\r
+\r
+/* Invariant: input stream is never overconsumed:\r
+ * invalid input implies that the whole stream is invalid -> any amount of\r
+ input could be read and discarded\r
+ * when result is "needs more input", then at leat one more byte is REQUIRED\r
+ to complete decoding; all input data MUST be consumed by decoder, so\r
+ client could swap the input buffer\r
+ * when result is "needs more output" decoder MUST ensure that it doesn't\r
+ hold more than 7 bits in bit reader; this saves client from swapping input\r
+ buffer ahead of time\r
+ * when result is "success" decoder MUST return all unused data back to input\r
+ buffer; this is possible because the invariant is hold on enter\r
+*/\r
+BrotliDecoderResult BrotliDecoderDecompressStream(\r
+ BrotliDecoderState* s, size_t* available_in, const uint8_t** next_in,\r
+ size_t* available_out, uint8_t** next_out, size_t* total_out) {\r
+ BrotliDecoderErrorCode result = BROTLI_DECODER_SUCCESS;\r
+ BrotliBitReader* br = &s->br;\r
+ if (s->buffer_length == 0) { /* Just connect bit reader to input stream. */\r
+ br->avail_in = *available_in;\r
+ br->next_in = *next_in;\r
+ } else {\r
+ /* At least one byte of input is required. More than one byte of input may\r
+ be required to complete the transaction -> reading more data must be\r
+ done in a loop -> do it in a main loop. */\r
+ result = BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ br->next_in = &s->buffer.u8[0];\r
+ }\r
+ /* State machine */\r
+ for (;;) {\r
+ if (result != BROTLI_DECODER_SUCCESS) { /* Error, needs more input/output */\r
+ if (result == BROTLI_DECODER_NEEDS_MORE_INPUT) {\r
+ if (s->ringbuffer != 0) { /* Proactively push output. */\r
+ WriteRingBuffer(s, available_out, next_out, total_out);\r
+ }\r
+ if (s->buffer_length != 0) { /* Used with internal buffer. */\r
+ if (br->avail_in == 0) { /* Successfully finished read transaction. */\r
+ /* Accamulator contains less than 8 bits, because internal buffer\r
+ is expanded byte-by-byte until it is enough to complete read. */\r
+ s->buffer_length = 0;\r
+ /* Switch to input stream and restart. */\r
+ result = BROTLI_DECODER_SUCCESS;\r
+ br->avail_in = *available_in;\r
+ br->next_in = *next_in;\r
+ continue;\r
+ } else if (*available_in != 0) {\r
+ /* Not enough data in buffer, but can take one more byte from\r
+ input stream. */\r
+ result = BROTLI_DECODER_SUCCESS;\r
+ s->buffer.u8[s->buffer_length] = **next_in;\r
+ s->buffer_length++;\r
+ br->avail_in = s->buffer_length;\r
+ (*next_in)++;\r
+ (*available_in)--;\r
+ /* Retry with more data in buffer. */\r
+ continue;\r
+ }\r
+ /* Can't finish reading and no more input.*/\r
+ break;\r
+ } else { /* Input stream doesn't contain enough input. */\r
+ /* Copy tail to internal buffer and return. */\r
+ *next_in = br->next_in;\r
+ *available_in = br->avail_in;\r
+ while (*available_in) {\r
+ s->buffer.u8[s->buffer_length] = **next_in;\r
+ s->buffer_length++;\r
+ (*next_in)++;\r
+ (*available_in)--;\r
+ }\r
+ break;\r
+ }\r
+ /* Unreachable. */\r
+ }\r
+\r
+ /* Fail or needs more output. */\r
+\r
+ if (s->buffer_length != 0) {\r
+ /* Just consumed the buffered input and produced some output. Otherwise\r
+ it would result in "needs more input". Reset internal buffer.*/\r
+ s->buffer_length = 0;\r
+ } else {\r
+ /* Using input stream in last iteration. When decoder switches to input\r
+ stream it has less than 8 bits in accamulator, so it is safe to\r
+ return unused accamulator bits there. */\r
+ BrotliBitReaderUnload(br);\r
+ *available_in = br->avail_in;\r
+ *next_in = br->next_in;\r
+ }\r
+ break;\r
+ }\r
+ switch (s->state) {\r
+ case BROTLI_STATE_UNINITED:\r
+ /* Prepare to the first read. */\r
+ if (!BrotliWarmupBitReader(br)) {\r
+ result = BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ break;\r
+ }\r
+ /* Decode window size. */\r
+ s->window_bits = DecodeWindowBits(br); /* Reads 1..7 bits. */\r
+ BROTLI_LOG_UINT(s->window_bits);\r
+ if (s->window_bits == 9) {\r
+ /* Value 9 is reserved for future use. */\r
+ result = BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_WINDOW_BITS);\r
+ break;\r
+ }\r
+ /* Maximum distance, see section 9.1. of the spec. */\r
+ s->max_backward_distance = (1 << s->window_bits) - 16;\r
+ /* Limit custom dictionary size. */\r
+ if (s->custom_dict_size >= s->max_backward_distance) {\r
+ s->custom_dict += s->custom_dict_size - s->max_backward_distance;\r
+ s->custom_dict_size = s->max_backward_distance;\r
+ }\r
+ s->max_backward_distance_minus_custom_dict_size =\r
+ s->max_backward_distance - s->custom_dict_size;\r
+\r
+ /* Allocate memory for both block_type_trees and block_len_trees. */\r
+ s->block_type_trees = (HuffmanCode*)BROTLI_ALLOC(s,\r
+ sizeof(HuffmanCode) * 3 *\r
+ (BROTLI_HUFFMAN_MAX_SIZE_258 + BROTLI_HUFFMAN_MAX_SIZE_26));\r
+ if (s->block_type_trees == 0) {\r
+ result = BROTLI_FAILURE(BROTLI_DECODER_ERROR_ALLOC_BLOCK_TYPE_TREES);\r
+ break;\r
+ }\r
+ s->block_len_trees =\r
+ s->block_type_trees + 3 * BROTLI_HUFFMAN_MAX_SIZE_258;\r
+\r
+ s->state = BROTLI_STATE_METABLOCK_BEGIN;\r
+ /* No break, continue to next state */\r
+ case BROTLI_STATE_METABLOCK_BEGIN:\r
+ BrotliDecoderStateMetablockBegin(s);\r
+ BROTLI_LOG_UINT(s->pos);\r
+ s->state = BROTLI_STATE_METABLOCK_HEADER;\r
+ /* No break, continue to next state */\r
+ case BROTLI_STATE_METABLOCK_HEADER:\r
+ result = DecodeMetaBlockLength(s, br); /* Reads 2 - 31 bits. */\r
+ if (result != BROTLI_DECODER_SUCCESS) {\r
+ break;\r
+ }\r
+ BROTLI_LOG_UINT(s->is_last_metablock);\r
+ BROTLI_LOG_UINT(s->meta_block_remaining_len);\r
+ BROTLI_LOG_UINT(s->is_metadata);\r
+ BROTLI_LOG_UINT(s->is_uncompressed);\r
+ if (s->is_metadata || s->is_uncompressed) {\r
+ if (!BrotliJumpToByteBoundary(br)) {\r
+ result = BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_PADDING_1);\r
+ break;\r
+ }\r
+ }\r
+ if (s->is_metadata) {\r
+ s->state = BROTLI_STATE_METADATA;\r
+ break;\r
+ }\r
+ if (s->meta_block_remaining_len == 0) {\r
+ s->state = BROTLI_STATE_METABLOCK_DONE;\r
+ break;\r
+ }\r
+ if (!s->ringbuffer) {\r
+ BrotliCalculateRingBufferSize(s, br);\r
+ }\r
+ if (s->is_uncompressed) {\r
+ s->state = BROTLI_STATE_UNCOMPRESSED;\r
+ break;\r
+ }\r
+ s->loop_counter = 0;\r
+ s->state = BROTLI_STATE_HUFFMAN_CODE_0;\r
+ break;\r
+ case BROTLI_STATE_UNCOMPRESSED: {\r
+ int bytes_copied = s->meta_block_remaining_len;\r
+ result = CopyUncompressedBlockToOutput(\r
+ available_out, next_out, total_out, s);\r
+ bytes_copied -= s->meta_block_remaining_len;\r
+ if (result != BROTLI_DECODER_SUCCESS) {\r
+ break;\r
+ }\r
+ s->state = BROTLI_STATE_METABLOCK_DONE;\r
+ break;\r
+ }\r
+ case BROTLI_STATE_METADATA:\r
+ for (; s->meta_block_remaining_len > 0; --s->meta_block_remaining_len) {\r
+ uint32_t bits;\r
+ /* Read one byte and ignore it. */\r
+ if (!BrotliSafeReadBits(br, 8, &bits)) {\r
+ result = BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ break;\r
+ }\r
+ }\r
+ if (result == BROTLI_DECODER_SUCCESS) {\r
+ s->state = BROTLI_STATE_METABLOCK_DONE;\r
+ }\r
+ break;\r
+ case BROTLI_STATE_HUFFMAN_CODE_0:\r
+ if (s->loop_counter >= 3) {\r
+ s->state = BROTLI_STATE_METABLOCK_HEADER_2;\r
+ break;\r
+ }\r
+ /* Reads 1..11 bits. */\r
+ result = DecodeVarLenUint8(s, br, &s->num_block_types[s->loop_counter]);\r
+ if (result != BROTLI_DECODER_SUCCESS) {\r
+ break;\r
+ }\r
+ s->num_block_types[s->loop_counter]++;\r
+ BROTLI_LOG_UINT(s->num_block_types[s->loop_counter]);\r
+ if (s->num_block_types[s->loop_counter] < 2) {\r
+ s->loop_counter++;\r
+ break;\r
+ }\r
+ s->state = BROTLI_STATE_HUFFMAN_CODE_1;\r
+ /* No break, continue to next state */\r
+ case BROTLI_STATE_HUFFMAN_CODE_1: {\r
+ int tree_offset = s->loop_counter * BROTLI_HUFFMAN_MAX_SIZE_258;\r
+ result = ReadHuffmanCode(s->num_block_types[s->loop_counter] + 2,\r
+ &s->block_type_trees[tree_offset], NULL, s);\r
+ if (result != BROTLI_DECODER_SUCCESS) break;\r
+ s->state = BROTLI_STATE_HUFFMAN_CODE_2;\r
+ /* No break, continue to next state */\r
+ }\r
+ case BROTLI_STATE_HUFFMAN_CODE_2: {\r
+ int tree_offset = s->loop_counter * BROTLI_HUFFMAN_MAX_SIZE_26;\r
+ result = ReadHuffmanCode(BROTLI_NUM_BLOCK_LEN_SYMBOLS,\r
+ &s->block_len_trees[tree_offset], NULL, s);\r
+ if (result != BROTLI_DECODER_SUCCESS) break;\r
+ s->state = BROTLI_STATE_HUFFMAN_CODE_3;\r
+ /* No break, continue to next state */\r
+ }\r
+ case BROTLI_STATE_HUFFMAN_CODE_3: {\r
+ int tree_offset = s->loop_counter * BROTLI_HUFFMAN_MAX_SIZE_26;\r
+ if (!SafeReadBlockLength(s, &s->block_length[s->loop_counter],\r
+ &s->block_len_trees[tree_offset], br)) {\r
+ result = BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ break;\r
+ }\r
+ BROTLI_LOG_UINT(s->block_length[s->loop_counter]);\r
+ s->loop_counter++;\r
+ s->state = BROTLI_STATE_HUFFMAN_CODE_0;\r
+ break;\r
+ }\r
+ case BROTLI_STATE_METABLOCK_HEADER_2: {\r
+ uint32_t bits;\r
+ if (!BrotliSafeReadBits(br, 6, &bits)) {\r
+ result = BROTLI_DECODER_NEEDS_MORE_INPUT;\r
+ break;\r
+ }\r
+ s->distance_postfix_bits = bits & BitMask(2);\r
+ bits >>= 2;\r
+ s->num_direct_distance_codes = BROTLI_NUM_DISTANCE_SHORT_CODES +\r
+ (bits << s->distance_postfix_bits);\r
+ BROTLI_LOG_UINT(s->num_direct_distance_codes);\r
+ BROTLI_LOG_UINT(s->distance_postfix_bits);\r
+ s->distance_postfix_mask = (int)BitMask(s->distance_postfix_bits);\r
+ s->context_modes =\r
+ (uint8_t*)BROTLI_ALLOC(s, (size_t)s->num_block_types[0]);\r
+ if (s->context_modes == 0) {\r
+ result = BROTLI_FAILURE(BROTLI_DECODER_ERROR_ALLOC_CONTEXT_MODES);\r
+ break;\r
+ }\r
+ s->loop_counter = 0;\r
+ s->state = BROTLI_STATE_CONTEXT_MODES;\r
+ /* No break, continue to next state */\r
+ }\r
+ case BROTLI_STATE_CONTEXT_MODES:\r
+ result = ReadContextModes(s);\r
+ if (result != BROTLI_DECODER_SUCCESS) {\r
+ break;\r
+ }\r
+ s->state = BROTLI_STATE_CONTEXT_MAP_1;\r
+ /* No break, continue to next state */\r
+ case BROTLI_STATE_CONTEXT_MAP_1:\r
+ result = DecodeContextMap(\r
+ s->num_block_types[0] << BROTLI_LITERAL_CONTEXT_BITS,\r
+ &s->num_literal_htrees, &s->context_map, s);\r
+ if (result != BROTLI_DECODER_SUCCESS) {\r
+ break;\r
+ }\r
+ DetectTrivialLiteralBlockTypes(s);\r
+ s->state = BROTLI_STATE_CONTEXT_MAP_2;\r
+ /* No break, continue to next state */\r
+ case BROTLI_STATE_CONTEXT_MAP_2:\r
+ {\r
+ uint32_t num_distance_codes =\r
+ s->num_direct_distance_codes + (48U << s->distance_postfix_bits);\r
+ result = DecodeContextMap(\r
+ s->num_block_types[2] << BROTLI_DISTANCE_CONTEXT_BITS,\r
+ &s->num_dist_htrees, &s->dist_context_map, s);\r
+ if (result != BROTLI_DECODER_SUCCESS) {\r
+ break;\r
+ }\r
+ BrotliDecoderHuffmanTreeGroupInit(\r
+ s, &s->literal_hgroup, BROTLI_NUM_LITERAL_SYMBOLS,\r
+ s->num_literal_htrees);\r
+ BrotliDecoderHuffmanTreeGroupInit(\r
+ s, &s->insert_copy_hgroup, BROTLI_NUM_COMMAND_SYMBOLS,\r
+ s->num_block_types[1]);\r
+ BrotliDecoderHuffmanTreeGroupInit(\r
+ s, &s->distance_hgroup, num_distance_codes,\r
+ s->num_dist_htrees);\r
+ if (s->literal_hgroup.codes == 0 ||\r
+ s->insert_copy_hgroup.codes == 0 ||\r
+ s->distance_hgroup.codes == 0) {\r
+ return SaveErrorCode(s,\r
+ BROTLI_FAILURE(BROTLI_DECODER_ERROR_ALLOC_TREE_GROUPS));\r
+ }\r
+ }\r
+ s->loop_counter = 0;\r
+ s->state = BROTLI_STATE_TREE_GROUP;\r
+ /* No break, continue to next state */\r
+ case BROTLI_STATE_TREE_GROUP:\r
+ {\r
+ HuffmanTreeGroup* hgroup = NULL;\r
+ switch (s->loop_counter) {\r
+ case 0:\r
+ hgroup = &s->literal_hgroup;\r
+ break;\r
+ case 1:\r
+ hgroup = &s->insert_copy_hgroup;\r
+ break;\r
+ case 2:\r
+ hgroup = &s->distance_hgroup;\r
+ break;\r
+ default:\r
+ return SaveErrorCode(s, BROTLI_FAILURE(\r
+ BROTLI_DECODER_ERROR_UNREACHABLE));\r
+ }\r
+ result = HuffmanTreeGroupDecode(hgroup, s);\r
+ }\r
+ if (result != BROTLI_DECODER_SUCCESS) break;\r
+ s->loop_counter++;\r
+ if (s->loop_counter >= 3) {\r
+ PrepareLiteralDecoding(s);\r
+ s->dist_context_map_slice = s->dist_context_map;\r
+ s->htree_command = s->insert_copy_hgroup.htrees[0];\r
+ if (!s->ringbuffer && !BrotliAllocateRingBuffer(s)) {\r
+ result = BROTLI_FAILURE(BROTLI_DECODER_ERROR_ALLOC_RING_BUFFER_2);\r
+ break;\r
+ }\r
+ s->state = BROTLI_STATE_COMMAND_BEGIN;\r
+ }\r
+ break;\r
+ case BROTLI_STATE_COMMAND_BEGIN:\r
+ case BROTLI_STATE_COMMAND_INNER:\r
+ case BROTLI_STATE_COMMAND_POST_DECODE_LITERALS:\r
+ case BROTLI_STATE_COMMAND_POST_WRAP_COPY:\r
+ result = ProcessCommands(s);\r
+ if (result == BROTLI_DECODER_NEEDS_MORE_INPUT) {\r
+ result = SafeProcessCommands(s);\r
+ }\r
+ break;\r
+ case BROTLI_STATE_COMMAND_INNER_WRITE:\r
+ case BROTLI_STATE_COMMAND_POST_WRITE_1:\r
+ case BROTLI_STATE_COMMAND_POST_WRITE_2:\r
+ result = WriteRingBuffer(s, available_out, next_out, total_out);\r
+ if (result != BROTLI_DECODER_SUCCESS) {\r
+ break;\r
+ }\r
+ s->max_distance = s->max_backward_distance;\r
+ if (s->state == BROTLI_STATE_COMMAND_POST_WRITE_1) {\r
+ memcpy(s->ringbuffer, s->ringbuffer_end, (size_t)s->pos);\r
+ if (s->meta_block_remaining_len == 0) {\r
+ /* Next metablock, if any */\r
+ s->state = BROTLI_STATE_METABLOCK_DONE;\r
+ } else {\r
+ s->state = BROTLI_STATE_COMMAND_BEGIN;\r
+ }\r
+ break;\r
+ } else if (s->state == BROTLI_STATE_COMMAND_POST_WRITE_2) {\r
+ s->state = BROTLI_STATE_COMMAND_POST_WRAP_COPY;\r
+ } else { /* BROTLI_STATE_COMMAND_INNER_WRITE */\r
+ if (s->loop_counter == 0) {\r
+ if (s->meta_block_remaining_len == 0) {\r
+ s->state = BROTLI_STATE_METABLOCK_DONE;\r
+ } else {\r
+ s->state = BROTLI_STATE_COMMAND_POST_DECODE_LITERALS;\r
+ }\r
+ break;\r
+ }\r
+ s->state = BROTLI_STATE_COMMAND_INNER;\r
+ }\r
+ break;\r
+ case BROTLI_STATE_METABLOCK_DONE:\r
+ if (s->meta_block_remaining_len < 0) {\r
+ result = BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_BLOCK_LENGTH_2);\r
+ break;\r
+ }\r
+ BrotliDecoderStateCleanupAfterMetablock(s);\r
+ if (!s->is_last_metablock) {\r
+ s->state = BROTLI_STATE_METABLOCK_BEGIN;\r
+ break;\r
+ }\r
+ if (!BrotliJumpToByteBoundary(br)) {\r
+ result = BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_PADDING_2);\r
+ break;\r
+ }\r
+ if (s->buffer_length == 0) {\r
+ BrotliBitReaderUnload(br);\r
+ *available_in = br->avail_in;\r
+ *next_in = br->next_in;\r
+ }\r
+ s->state = BROTLI_STATE_DONE;\r
+ /* No break, continue to next state */\r
+ case BROTLI_STATE_DONE:\r
+ if (s->ringbuffer != 0) {\r
+ result = WriteRingBuffer(s, available_out, next_out, total_out);\r
+ if (result != BROTLI_DECODER_SUCCESS) {\r
+ break;\r
+ }\r
+ }\r
+ return SaveErrorCode(s, result);\r
+ }\r
+ }\r
+ return SaveErrorCode(s, result);\r
+}\r
+\r
+void BrotliDecoderSetCustomDictionary(\r
+ BrotliDecoderState* s, size_t size, const uint8_t* dict) {\r
+ if (size > (1u << 24)) {\r
+ return;\r
+ }\r
+ s->custom_dict = dict;\r
+ s->custom_dict_size = (int)size;\r
+}\r
+\r
+BROTLI_BOOL BrotliDecoderHasMoreOutput(const BrotliDecoderState* s) {\r
+ return TO_BROTLI_BOOL(\r
+ s->ringbuffer != 0 && UnwrittenBytes(s, BROTLI_FALSE) != 0);\r
+}\r
+\r
+BROTLI_BOOL BrotliDecoderIsUsed(const BrotliDecoderState* s) {\r
+ return TO_BROTLI_BOOL(s->state != BROTLI_STATE_UNINITED ||\r
+ BrotliGetAvailableBits(&s->br) != 0);\r
+}\r
+\r
+BROTLI_BOOL BrotliDecoderIsFinished(const BrotliDecoderState* s) {\r
+ return TO_BROTLI_BOOL(s->state == BROTLI_STATE_DONE);\r
+}\r
+\r
+BrotliDecoderErrorCode BrotliDecoderGetErrorCode(const BrotliDecoderState* s) {\r
+ return (BrotliDecoderErrorCode)s->error_code;\r
+}\r
+\r
+const char* BrotliDecoderErrorString(BrotliDecoderErrorCode c) {\r
+ switch (c) {\r
+#define _BROTLI_ERROR_CODE_CASE(PREFIX, NAME, CODE) \\r
+ case BROTLI_DECODER ## PREFIX ## NAME: return #NAME;\r
+#define _BROTLI_NOTHING\r
+ BROTLI_DECODER_ERROR_CODES_LIST(_BROTLI_ERROR_CODE_CASE, _BROTLI_NOTHING)\r
+#undef _BROTLI_ERROR_CODE_CASE\r
+#undef _BROTLI_NOTHING\r
+ default: return "INVALID";\r
+ }\r
+}\r
+\r
+/* DEPRECATED >>> */\r
+BrotliState* BrotliCreateState(\r
+ brotli_alloc_func alloc, brotli_free_func free, void* opaque) {\r
+ return (BrotliState*)BrotliDecoderCreateInstance(alloc, free, opaque);\r
+}\r
+void BrotliDestroyState(BrotliState* state) {\r
+ BrotliDecoderDestroyInstance((BrotliDecoderState*)state);\r
+}\r
+BrotliResult BrotliDecompressBuffer(\r
+ size_t encoded_size, const uint8_t* encoded_buffer, size_t* decoded_size,\r
+ uint8_t* decoded_buffer) {\r
+ return (BrotliResult)BrotliDecoderDecompress(\r
+ encoded_size, encoded_buffer, decoded_size, decoded_buffer);\r
+}\r
+BrotliResult BrotliDecompressStream(\r
+ size_t* available_in, const uint8_t** next_in, size_t* available_out,\r
+ uint8_t** next_out, size_t* total_out, BrotliState* s) {\r
+ return (BrotliResult)BrotliDecoderDecompressStream((BrotliDecoderState*)s,\r
+ available_in, next_in, available_out, next_out, total_out);\r
+}\r
+void BrotliSetCustomDictionary(\r
+ size_t size, const uint8_t* dict, BrotliState* s) {\r
+ BrotliDecoderSetCustomDictionary((BrotliDecoderState*)s, size, dict);\r
+}\r
+BROTLI_BOOL BrotliStateIsStreamStart(const BrotliState* s) {\r
+ return !BrotliDecoderIsUsed((const BrotliDecoderState*)s);\r
+}\r
+BROTLI_BOOL BrotliStateIsStreamEnd(const BrotliState* s) {\r
+ return BrotliDecoderIsFinished((const BrotliDecoderState*)s);\r
+}\r
+BrotliErrorCode BrotliGetErrorCode(const BrotliState* s) {\r
+ return (BrotliErrorCode)BrotliDecoderGetErrorCode(\r
+ (const BrotliDecoderState*)s);\r
+}\r
+const char* BrotliErrorString(BrotliErrorCode c) {\r
+ return BrotliDecoderErrorString((BrotliDecoderErrorCode)c);\r
+}\r
+/* <<< DEPRECATED */\r
+\r
+#if defined(__cplusplus) || defined(c_plusplus)\r
+} /* extern "C" */\r
+#endif\r
projects / mirror_edk2.git / blobdiff