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-rw-r--r--modules/brotli/dec/bit_reader.c28
-rw-r--r--modules/brotli/dec/bit_reader.h74
-rw-r--r--modules/brotli/dec/decode.c604
-rw-r--r--modules/brotli/dec/huffman.h18
-rw-r--r--modules/brotli/dec/prefix.h18
-rw-r--r--modules/brotli/dec/state.c23
-rw-r--r--modules/brotli/dec/state.h181
7 files changed, 598 insertions, 348 deletions
diff --git a/modules/brotli/dec/bit_reader.c b/modules/brotli/dec/bit_reader.c
index 722fd906d..7f7b256a4 100644
--- a/modules/brotli/dec/bit_reader.c
+++ b/modules/brotli/dec/bit_reader.c
@@ -15,6 +15,17 @@
extern "C" {
#endif
+const uint32_t kBrotliBitMask[33] = { 0x00000000,
+ 0x00000001, 0x00000003, 0x00000007, 0x0000000F,
+ 0x0000001F, 0x0000003F, 0x0000007F, 0x000000FF,
+ 0x000001FF, 0x000003FF, 0x000007FF, 0x00000FFF,
+ 0x00001FFF, 0x00003FFF, 0x00007FFF, 0x0000FFFF,
+ 0x0001FFFF, 0x0003FFFF, 0x0007FFFF, 0x000FFFFF,
+ 0x001FFFFF, 0x003FFFFF, 0x007FFFFF, 0x00FFFFFF,
+ 0x01FFFFFF, 0x03FFFFFF, 0x07FFFFFF, 0x0FFFFFFF,
+ 0x1FFFFFFF, 0x3FFFFFFF, 0x7FFFFFFF, 0xFFFFFFFF
+};
+
void BrotliInitBitReader(BrotliBitReader* const br) {
br->val_ = 0;
br->bit_pos_ = sizeof(br->val_) << 3;
@@ -43,6 +54,23 @@ BROTLI_BOOL BrotliWarmupBitReader(BrotliBitReader* const br) {
return BROTLI_TRUE;
}
+BROTLI_BOOL BrotliSafeReadBits32Slow(BrotliBitReader* const br,
+ uint32_t n_bits, uint32_t* val) {
+ uint32_t low_val;
+ uint32_t high_val;
+ BrotliBitReaderState memento;
+ BROTLI_DCHECK(n_bits <= 32);
+ BROTLI_DCHECK(n_bits > 24);
+ BrotliBitReaderSaveState(br, &memento);
+ if (!BrotliSafeReadBits(br, 16, &low_val) ||
+ !BrotliSafeReadBits(br, n_bits - 16, &high_val)) {
+ BrotliBitReaderRestoreState(br, &memento);
+ return BROTLI_FALSE;
+ }
+ *val = low_val | (high_val << 16);
+ return BROTLI_TRUE;
+}
+
#if defined(__cplusplus) || defined(c_plusplus)
} /* extern "C" */
#endif
diff --git a/modules/brotli/dec/bit_reader.h b/modules/brotli/dec/bit_reader.h
index c06e91419..22bc060ca 100644
--- a/modules/brotli/dec/bit_reader.h
+++ b/modules/brotli/dec/bit_reader.h
@@ -11,6 +11,7 @@
#include <string.h> /* memcpy */
+#include "../common/constants.h"
#include "../common/platform.h"
#include <brotli/types.h>
@@ -20,16 +21,7 @@ extern "C" {
#define BROTLI_SHORT_FILL_BIT_WINDOW_READ (sizeof(brotli_reg_t) >> 1)
-static const uint32_t kBitMask[33] = { 0x00000000,
- 0x00000001, 0x00000003, 0x00000007, 0x0000000F,
- 0x0000001F, 0x0000003F, 0x0000007F, 0x000000FF,
- 0x000001FF, 0x000003FF, 0x000007FF, 0x00000FFF,
- 0x00001FFF, 0x00003FFF, 0x00007FFF, 0x0000FFFF,
- 0x0001FFFF, 0x0003FFFF, 0x0007FFFF, 0x000FFFFF,
- 0x001FFFFF, 0x003FFFFF, 0x007FFFFF, 0x00FFFFFF,
- 0x01FFFFFF, 0x03FFFFFF, 0x07FFFFFF, 0x0FFFFFFF,
- 0x1FFFFFFF, 0x3FFFFFFF, 0x7FFFFFFF, 0xFFFFFFFF
-};
+BROTLI_INTERNAL extern const uint32_t kBrotliBitMask[33];
static BROTLI_INLINE uint32_t BitMask(uint32_t n) {
if (BROTLI_IS_CONSTANT(n) || BROTLI_HAS_UBFX) {
@@ -37,7 +29,7 @@ static BROTLI_INLINE uint32_t BitMask(uint32_t n) {
"Unsigned Bit Field Extract" UBFX instruction on ARM. */
return ~((0xFFFFFFFFu) << n);
} else {
- return kBitMask[n];
+ return kBrotliBitMask[n];
}
}
@@ -65,6 +57,12 @@ BROTLI_INTERNAL void BrotliInitBitReader(BrotliBitReader* const br);
reading. */
BROTLI_INTERNAL BROTLI_BOOL BrotliWarmupBitReader(BrotliBitReader* const br);
+/* Fallback for BrotliSafeReadBits32. Extracted as noninlined method to unburden
+ the main code-path. Never called for RFC brotli streams, required only for
+ "large-window" mode and other extensions. */
+BROTLI_INTERNAL BROTLI_NOINLINE BROTLI_BOOL BrotliSafeReadBits32Slow(
+ BrotliBitReader* const br, uint32_t n_bits, uint32_t* val);
+
static BROTLI_INLINE void BrotliBitReaderSaveState(
BrotliBitReader* const from, BrotliBitReaderState* to) {
to->val_ = from->val_;
@@ -87,8 +85,11 @@ static BROTLI_INLINE uint32_t BrotliGetAvailableBits(
}
/* Returns amount of unread bytes the bit reader still has buffered from the
- BrotliInput, including whole bytes in br->val_. */
+ BrotliInput, including whole bytes in br->val_. Result is capped with
+ maximal ring-buffer size (larger number won't be utilized anyway). */
static BROTLI_INLINE size_t BrotliGetRemainingBytes(BrotliBitReader* br) {
+ static const size_t kCap = (size_t)1 << BROTLI_LARGE_MAX_WBITS;
+ if (br->avail_in > kCap) return kCap;
return br->avail_in + (BrotliGetAvailableBits(br) >> 3);
}
@@ -237,15 +238,17 @@ static BROTLI_INLINE void BrotliBitReaderUnload(BrotliBitReader* br) {
static BROTLI_INLINE void BrotliTakeBits(
BrotliBitReader* const br, uint32_t n_bits, uint32_t* val) {
*val = (uint32_t)BrotliGetBitsUnmasked(br) & BitMask(n_bits);
- BROTLI_LOG(("[BrotliReadBits] %d %d %d val: %6x\n",
+ BROTLI_LOG(("[BrotliTakeBits] %d %d %d val: %6x\n",
(int)br->avail_in, (int)br->bit_pos_, (int)n_bits, (int)*val));
BrotliDropBits(br, n_bits);
}
/* Reads the specified number of bits from |br| and advances the bit pos.
- Assumes that there is enough input to perform BrotliFillBitWindow. */
-static BROTLI_INLINE uint32_t BrotliReadBits(
+ Assumes that there is enough input to perform BrotliFillBitWindow.
+ Up to 24 bits are allowed to be requested from this method. */
+static BROTLI_INLINE uint32_t BrotliReadBits24(
BrotliBitReader* const br, uint32_t n_bits) {
+ BROTLI_DCHECK(n_bits <= 24);
if (BROTLI_64_BITS || (n_bits <= 16)) {
uint32_t val;
BrotliFillBitWindow(br, n_bits);
@@ -262,10 +265,32 @@ static BROTLI_INLINE uint32_t BrotliReadBits(
}
}
+/* Same as BrotliReadBits24, but allows reading up to 32 bits. */
+static BROTLI_INLINE uint32_t BrotliReadBits32(
+ BrotliBitReader* const br, uint32_t n_bits) {
+ BROTLI_DCHECK(n_bits <= 32);
+ if (BROTLI_64_BITS || (n_bits <= 16)) {
+ uint32_t val;
+ BrotliFillBitWindow(br, n_bits);
+ BrotliTakeBits(br, n_bits, &val);
+ return val;
+ } else {
+ uint32_t low_val;
+ uint32_t high_val;
+ BrotliFillBitWindow(br, 16);
+ BrotliTakeBits(br, 16, &low_val);
+ BrotliFillBitWindow(br, 16);
+ BrotliTakeBits(br, n_bits - 16, &high_val);
+ return low_val | (high_val << 16);
+ }
+}
+
/* Tries to read the specified amount of bits. Returns BROTLI_FALSE, if there
- is not enough input. |n_bits| MUST be positive. */
+ is not enough input. |n_bits| MUST be positive.
+ Up to 24 bits are allowed to be requested from this method. */
static BROTLI_INLINE BROTLI_BOOL BrotliSafeReadBits(
BrotliBitReader* const br, uint32_t n_bits, uint32_t* val) {
+ BROTLI_DCHECK(n_bits <= 24);
while (BrotliGetAvailableBits(br) < n_bits) {
if (!BrotliPullByte(br)) {
return BROTLI_FALSE;
@@ -275,6 +300,23 @@ static BROTLI_INLINE BROTLI_BOOL BrotliSafeReadBits(
return BROTLI_TRUE;
}
+/* Same as BrotliSafeReadBits, but allows reading up to 32 bits. */
+static BROTLI_INLINE BROTLI_BOOL BrotliSafeReadBits32(
+ BrotliBitReader* const br, uint32_t n_bits, uint32_t* val) {
+ BROTLI_DCHECK(n_bits <= 32);
+ if (BROTLI_64_BITS || (n_bits <= 24)) {
+ while (BrotliGetAvailableBits(br) < n_bits) {
+ if (!BrotliPullByte(br)) {
+ return BROTLI_FALSE;
+ }
+ }
+ BrotliTakeBits(br, n_bits, val);
+ return BROTLI_TRUE;
+ } else {
+ return BrotliSafeReadBits32Slow(br, n_bits, val);
+ }
+}
+
/* Advances the bit reader position to the next byte boundary and verifies
that any skipped bits are set to zero. */
static BROTLI_INLINE BROTLI_BOOL BrotliJumpToByteBoundary(BrotliBitReader* br) {
diff --git a/modules/brotli/dec/decode.c b/modules/brotli/dec/decode.c
index 08bd76ca1..ae5a3d3fa 100644
--- a/modules/brotli/dec/decode.c
+++ b/modules/brotli/dec/decode.c
@@ -41,7 +41,8 @@ extern "C" {
/* We need the slack region for the following reasons:
- doing up to two 16-byte copies for fast backward copying
- - inserting transformed dictionary word (5 prefix + 24 base + 8 suffix) */
+ - inserting transformed dictionary word:
+ 5 prefix + 24 base + 8 suffix */
static const uint32_t kRingBufferWriteAheadSlack = 42;
static const uint8_t kCodeLengthCodeOrder[BROTLI_CODE_LENGTH_CODES] = {
@@ -274,7 +275,8 @@ static BrotliDecoderErrorCode BROTLI_NOINLINE DecodeMetaBlockLength(
s->loop_counter = i;
return BROTLI_DECODER_NEEDS_MORE_INPUT;
}
- if (i + 1 == s->size_nibbles && s->size_nibbles > 4 && bits == 0) {
+ if (i + 1 == (int)s->size_nibbles && s->size_nibbles > 4 &&
+ bits == 0) {
return BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_EXUBERANT_NIBBLE);
}
s->meta_block_remaining_len |= (int)(bits << (i * 4));
@@ -323,7 +325,8 @@ static BrotliDecoderErrorCode BROTLI_NOINLINE DecodeMetaBlockLength(
s->loop_counter = i;
return BROTLI_DECODER_NEEDS_MORE_INPUT;
}
- if (i + 1 == s->size_nibbles && s->size_nibbles > 1 && bits == 0) {
+ if (i + 1 == (int)s->size_nibbles && s->size_nibbles > 1 &&
+ bits == 0) {
return BROTLI_FAILURE(
BROTLI_DECODER_ERROR_FORMAT_EXUBERANT_META_NIBBLE);
}
@@ -470,32 +473,34 @@ static BROTLI_INLINE uint32_t Log2Floor(uint32_t x) {
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, uint32_t max_symbol, BrotliDecoderState* s) {
+ uint32_t alphabet_size_max, uint32_t alphabet_size_limit,
+ 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;
- uint32_t num_symbols = s->symbol;
+ BrotliMetablockHeaderArena* h = &s->arena.header;
+ uint32_t max_bits = Log2Floor(alphabet_size_max - 1);
+ uint32_t i = h->sub_loop_counter;
+ uint32_t num_symbols = h->symbol;
while (i <= num_symbols) {
uint32_t v;
if (BROTLI_PREDICT_FALSE(!BrotliSafeReadBits(br, max_bits, &v))) {
- s->sub_loop_counter = i;
- s->substate_huffman = BROTLI_STATE_HUFFMAN_SIMPLE_READ;
+ h->sub_loop_counter = i;
+ h->substate_huffman = BROTLI_STATE_HUFFMAN_SIMPLE_READ;
return BROTLI_DECODER_NEEDS_MORE_INPUT;
}
- if (v >= max_symbol) {
+ if (v >= alphabet_size_limit) {
return
BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_SIMPLE_HUFFMAN_ALPHABET);
}
- s->symbols_lists_array[i] = (uint16_t)v;
- BROTLI_LOG_UINT(s->symbols_lists_array[i]);
+ h->symbols_lists_array[i] = (uint16_t)v;
+ BROTLI_LOG_UINT(h->symbols_lists_array[i]);
++i;
}
for (i = 0; i < num_symbols; ++i) {
uint32_t k = i + 1;
for (; k <= num_symbols; ++k) {
- if (s->symbols_lists_array[i] == s->symbols_lists_array[k]) {
+ if (h->symbols_lists_array[i] == h->symbols_lists_array[k]) {
return BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_SIMPLE_HUFFMAN_SAME);
}
}
@@ -588,27 +593,28 @@ static BROTLI_INLINE void ProcessRepeatedCodeLength(uint32_t code_len,
static BrotliDecoderErrorCode ReadSymbolCodeLengths(
uint32_t alphabet_size, BrotliDecoderState* s) {
BrotliBitReader* br = &s->br;
- uint32_t symbol = s->symbol;
- uint32_t repeat = s->repeat;
- uint32_t space = s->space;
- uint32_t prev_code_len = s->prev_code_len;
- uint32_t repeat_code_len = s->repeat_code_len;
- uint16_t* symbol_lists = s->symbol_lists;
- uint16_t* code_length_histo = s->code_length_histo;
- int* next_symbol = s->next_symbol;
+ BrotliMetablockHeaderArena* h = &s->arena.header;
+ uint32_t symbol = h->symbol;
+ uint32_t repeat = h->repeat;
+ uint32_t space = h->space;
+ uint32_t prev_code_len = h->prev_code_len;
+ uint32_t repeat_code_len = h->repeat_code_len;
+ uint16_t* symbol_lists = h->symbol_lists;
+ uint16_t* code_length_histo = h->code_length_histo;
+ int* next_symbol = h->next_symbol;
if (!BrotliWarmupBitReader(br)) {
return BROTLI_DECODER_NEEDS_MORE_INPUT;
}
while (symbol < alphabet_size && space > 0) {
- const HuffmanCode* p = s->table;
+ const HuffmanCode* p = h->table;
uint32_t code_len;
BROTLI_HC_MARK_TABLE_FOR_FAST_LOAD(p);
if (!BrotliCheckInputAmount(br, BROTLI_SHORT_FILL_BIT_WINDOW_READ)) {
- s->symbol = symbol;
- s->repeat = repeat;
- s->prev_code_len = prev_code_len;
- s->repeat_code_len = repeat_code_len;
- s->space = space;
+ h->symbol = symbol;
+ h->repeat = repeat;
+ h->prev_code_len = prev_code_len;
+ h->repeat_code_len = repeat_code_len;
+ h->space = space;
return BROTLI_DECODER_NEEDS_MORE_INPUT;
}
BrotliFillBitWindow16(br);
@@ -630,16 +636,17 @@ static BrotliDecoderErrorCode ReadSymbolCodeLengths(
symbol_lists, code_length_histo, next_symbol);
}
}
- s->space = space;
+ h->space = space;
return BROTLI_DECODER_SUCCESS;
}
static BrotliDecoderErrorCode SafeReadSymbolCodeLengths(
uint32_t alphabet_size, BrotliDecoderState* s) {
BrotliBitReader* br = &s->br;
+ BrotliMetablockHeaderArena* h = &s->arena.header;
BROTLI_BOOL get_byte = BROTLI_FALSE;
- while (s->symbol < alphabet_size && s->space > 0) {
- const HuffmanCode* p = s->table;
+ while (h->symbol < alphabet_size && h->space > 0) {
+ const HuffmanCode* p = h->table;
uint32_t code_len;
uint32_t available_bits;
uint32_t bits = 0;
@@ -659,9 +666,9 @@ static BrotliDecoderErrorCode SafeReadSymbolCodeLengths(
code_len = BROTLI_HC_FAST_LOAD_VALUE(p); /* code_len == 0..17 */
if (code_len < BROTLI_REPEAT_PREVIOUS_CODE_LENGTH) {
BrotliDropBits(br, BROTLI_HC_FAST_LOAD_BITS(p));
- ProcessSingleCodeLength(code_len, &s->symbol, &s->repeat, &s->space,
- &s->prev_code_len, s->symbol_lists, s->code_length_histo,
- s->next_symbol);
+ ProcessSingleCodeLength(code_len, &h->symbol, &h->repeat, &h->space,
+ &h->prev_code_len, h->symbol_lists, h->code_length_histo,
+ h->next_symbol);
} else { /* code_len == 16..17, extra_bits == 2..3 */
uint32_t extra_bits = code_len - 14U;
uint32_t repeat_delta = (bits >> BROTLI_HC_FAST_LOAD_BITS(p)) &
@@ -672,9 +679,9 @@ static BrotliDecoderErrorCode SafeReadSymbolCodeLengths(
}
BrotliDropBits(br, BROTLI_HC_FAST_LOAD_BITS(p) + extra_bits);
ProcessRepeatedCodeLength(code_len, repeat_delta, alphabet_size,
- &s->symbol, &s->repeat, &s->space, &s->prev_code_len,
- &s->repeat_code_len, s->symbol_lists, s->code_length_histo,
- s->next_symbol);
+ &h->symbol, &h->repeat, &h->space, &h->prev_code_len,
+ &h->repeat_code_len, h->symbol_lists, h->code_length_histo,
+ h->next_symbol);
}
}
return BROTLI_DECODER_SUCCESS;
@@ -684,9 +691,10 @@ static BrotliDecoderErrorCode SafeReadSymbolCodeLengths(
Each code is 2..4 bits long. In total 30..72 bits are used. */
static BrotliDecoderErrorCode ReadCodeLengthCodeLengths(BrotliDecoderState* s) {
BrotliBitReader* br = &s->br;
- uint32_t num_codes = s->repeat;
- unsigned space = s->space;
- uint32_t i = s->sub_loop_counter;
+ BrotliMetablockHeaderArena* h = &s->arena.header;
+ uint32_t num_codes = h->repeat;
+ unsigned space = h->space;
+ uint32_t i = h->sub_loop_counter;
for (; i < BROTLI_CODE_LENGTH_CODES; ++i) {
const uint8_t code_len_idx = kCodeLengthCodeOrder[i];
uint32_t ix;
@@ -699,21 +707,21 @@ static BrotliDecoderErrorCode ReadCodeLengthCodeLengths(BrotliDecoderState* s) {
ix = 0;
}
if (kCodeLengthPrefixLength[ix] > available_bits) {
- s->sub_loop_counter = i;
- s->repeat = num_codes;
- s->space = space;
- s->substate_huffman = BROTLI_STATE_HUFFMAN_COMPLEX;
+ h->sub_loop_counter = i;
+ h->repeat = num_codes;
+ h->space = space;
+ h->substate_huffman = BROTLI_STATE_HUFFMAN_COMPLEX;
return BROTLI_DECODER_NEEDS_MORE_INPUT;
}
}
v = kCodeLengthPrefixValue[ix];
BrotliDropBits(br, kCodeLengthPrefixLength[ix]);
- s->code_length_code_lengths[code_len_idx] = (uint8_t)v;
- BROTLI_LOG_ARRAY_INDEX(s->code_length_code_lengths, code_len_idx);
+ h->code_length_code_lengths[code_len_idx] = (uint8_t)v;
+ BROTLI_LOG_ARRAY_INDEX(h->code_length_code_lengths, code_len_idx);
if (v != 0) {
space = space - (32U >> v);
++num_codes;
- ++s->code_length_histo[v];
+ ++h->code_length_histo[v];
if (space - 1U >= 32U) {
/* space is 0 or wrapped around. */
break;
@@ -737,49 +745,48 @@ static BrotliDecoderErrorCode ReadCodeLengthCodeLengths(BrotliDecoderState* s) {
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. */
-static BrotliDecoderErrorCode ReadHuffmanCode(uint32_t alphabet_size,
- uint32_t max_symbol,
+static BrotliDecoderErrorCode ReadHuffmanCode(uint32_t alphabet_size_max,
+ uint32_t alphabet_size_limit,
HuffmanCode* table,
uint32_t* opt_table_size,
BrotliDecoderState* s) {
BrotliBitReader* br = &s->br;
- /* Unnecessary masking, but might be good for safety. */
- alphabet_size &= 0x7FF;
+ BrotliMetablockHeaderArena* h = &s->arena.header;
/* State machine. */
for (;;) {
- switch (s->substate_huffman) {
+ switch (h->substate_huffman) {
case BROTLI_STATE_HUFFMAN_NONE:
- if (!BrotliSafeReadBits(br, 2, &s->sub_loop_counter)) {
+ if (!BrotliSafeReadBits(br, 2, &h->sub_loop_counter)) {
return BROTLI_DECODER_NEEDS_MORE_INPUT;
}
- BROTLI_LOG_UINT(s->sub_loop_counter);
+ BROTLI_LOG_UINT(h->sub_loop_counter);
/* The value is used as follows:
1 for simple code;
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 */
- memset(&s->code_length_histo[0], 0, sizeof(s->code_length_histo[0]) *
+ if (h->sub_loop_counter != 1) {
+ h->space = 32;
+ h->repeat = 0; /* num_codes */
+ memset(&h->code_length_histo[0], 0, sizeof(h->code_length_histo[0]) *
(BROTLI_HUFFMAN_MAX_CODE_LENGTH_CODE_LENGTH + 1));
- memset(&s->code_length_code_lengths[0], 0,
- sizeof(s->code_length_code_lengths));
- s->substate_huffman = BROTLI_STATE_HUFFMAN_COMPLEX;
+ memset(&h->code_length_code_lengths[0], 0,
+ sizeof(h->code_length_code_lengths));
+ h->substate_huffman = BROTLI_STATE_HUFFMAN_COMPLEX;
continue;
}
/* Fall through. */
case BROTLI_STATE_HUFFMAN_SIMPLE_SIZE:
/* Read symbols, codes & code lengths directly. */
- if (!BrotliSafeReadBits(br, 2, &s->symbol)) { /* num_symbols */
- s->substate_huffman = BROTLI_STATE_HUFFMAN_SIMPLE_SIZE;
+ if (!BrotliSafeReadBits(br, 2, &h->symbol)) { /* num_symbols */
+ h->substate_huffman = BROTLI_STATE_HUFFMAN_SIMPLE_SIZE;
return BROTLI_DECODER_NEEDS_MORE_INPUT;
}
- s->sub_loop_counter = 0;
+ h->sub_loop_counter = 0;
/* Fall through. */
case BROTLI_STATE_HUFFMAN_SIMPLE_READ: {
BrotliDecoderErrorCode result =
- ReadSimpleHuffmanSymbols(alphabet_size, max_symbol, s);
+ ReadSimpleHuffmanSymbols(alphabet_size_max, alphabet_size_limit, s);
if (result != BROTLI_DECODER_SUCCESS) {
return result;
}
@@ -788,21 +795,21 @@ static BrotliDecoderErrorCode ReadHuffmanCode(uint32_t alphabet_size,
case BROTLI_STATE_HUFFMAN_SIMPLE_BUILD: {
uint32_t table_size;
- if (s->symbol == 3) {
+ if (h->symbol == 3) {
uint32_t bits;
if (!BrotliSafeReadBits(br, 1, &bits)) {
- s->substate_huffman = BROTLI_STATE_HUFFMAN_SIMPLE_BUILD;
+ h->substate_huffman = BROTLI_STATE_HUFFMAN_SIMPLE_BUILD;
return BROTLI_DECODER_NEEDS_MORE_INPUT;
}
- s->symbol += bits;
+ h->symbol += bits;
}
- BROTLI_LOG_UINT(s->symbol);
+ BROTLI_LOG_UINT(h->symbol);
table_size = BrotliBuildSimpleHuffmanTable(
- table, HUFFMAN_TABLE_BITS, s->symbols_lists_array, s->symbol);
+ table, HUFFMAN_TABLE_BITS, h->symbols_lists_array, h->symbol);
if (opt_table_size) {
*opt_table_size = table_size;
}
- s->substate_huffman = BROTLI_STATE_HUFFMAN_NONE;
+ h->substate_huffman = BROTLI_STATE_HUFFMAN_NONE;
return BROTLI_DECODER_SUCCESS;
}
@@ -813,44 +820,45 @@ static BrotliDecoderErrorCode ReadHuffmanCode(uint32_t alphabet_size,
if (result != BROTLI_DECODER_SUCCESS) {
return result;
}
- BrotliBuildCodeLengthsHuffmanTable(s->table,
- s->code_length_code_lengths,
- s->code_length_histo);
- memset(&s->code_length_histo[0], 0, sizeof(s->code_length_histo));
+ BrotliBuildCodeLengthsHuffmanTable(h->table,
+ h->code_length_code_lengths,
+ h->code_length_histo);
+ memset(&h->code_length_histo[0], 0, sizeof(h->code_length_histo));
for (i = 0; i <= BROTLI_HUFFMAN_MAX_CODE_LENGTH; ++i) {
- s->next_symbol[i] = (int)i - (BROTLI_HUFFMAN_MAX_CODE_LENGTH + 1);
- s->symbol_lists[s->next_symbol[i]] = 0xFFFF;
+ h->next_symbol[i] = (int)i - (BROTLI_HUFFMAN_MAX_CODE_LENGTH + 1);
+ h->symbol_lists[h->next_symbol[i]] = 0xFFFF;
}
- s->symbol = 0;
- s->prev_code_len = BROTLI_INITIAL_REPEATED_CODE_LENGTH;
- s->repeat = 0;
- s->repeat_code_len = 0;
- s->space = 32768;
- s->substate_huffman = BROTLI_STATE_HUFFMAN_LENGTH_SYMBOLS;
+ h->symbol = 0;
+ h->prev_code_len = BROTLI_INITIAL_REPEATED_CODE_LENGTH;
+ h->repeat = 0;
+ h->repeat_code_len = 0;
+ h->space = 32768;
+ h->substate_huffman = BROTLI_STATE_HUFFMAN_LENGTH_SYMBOLS;
}
/* Fall through. */
case BROTLI_STATE_HUFFMAN_LENGTH_SYMBOLS: {
uint32_t table_size;
- BrotliDecoderErrorCode result = ReadSymbolCodeLengths(max_symbol, s);
+ BrotliDecoderErrorCode result = ReadSymbolCodeLengths(
+ alphabet_size_limit, s);
if (result == BROTLI_DECODER_NEEDS_MORE_INPUT) {
- result = SafeReadSymbolCodeLengths(max_symbol, s);
+ result = SafeReadSymbolCodeLengths(alphabet_size_limit, s);
}
if (result != BROTLI_DECODER_SUCCESS) {
return result;
}
- if (s->space != 0) {
- BROTLI_LOG(("[ReadHuffmanCode] space = %d\n", (int)s->space));
+ if (h->space != 0) {
+ BROTLI_LOG(("[ReadHuffmanCode] space = %d\n", (int)h->space));
return BROTLI_FAILURE(BROTLI_DECODER_ERROR_FORMAT_HUFFMAN_SPACE);
}
table_size = BrotliBuildHuffmanTable(
- table, HUFFMAN_TABLE_BITS, s->symbol_lists, s->code_length_histo);
+ table, HUFFMAN_TABLE_BITS, h->symbol_lists, h->code_length_histo);
if (opt_table_size) {
*opt_table_size = table_size;
}
- s->substate_huffman = BROTLI_STATE_HUFFMAN_NONE;
+ h->substate_huffman = BROTLI_STATE_HUFFMAN_NONE;
return BROTLI_DECODER_SUCCESS;
}
@@ -867,8 +875,8 @@ 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 */
- return kBlockLengthPrefixCode[code].offset + BrotliReadBits(br, nbits);
+ nbits = _kBrotliPrefixCodeRanges[code].nbits; /* nbits == 2..24 */
+ return _kBrotliPrefixCodeRanges[code].offset + BrotliReadBits24(br, nbits);
}
/* WARNING: if state is not BROTLI_STATE_READ_BLOCK_LENGTH_NONE, then
@@ -886,13 +894,14 @@ static BROTLI_INLINE BROTLI_BOOL SafeReadBlockLength(
}
{
uint32_t bits;
- uint32_t nbits = kBlockLengthPrefixCode[index].nbits; /* nbits == 2..24 */
+ uint32_t nbits = _kBrotliPrefixCodeRanges[index].nbits;
+ uint32_t offset = _kBrotliPrefixCodeRanges[index].offset;
if (!BrotliSafeReadBits(br, nbits, &bits)) {
s->block_length_index = index;
s->substate_read_block_length = BROTLI_STATE_READ_BLOCK_LENGTH_SUFFIX;
return BROTLI_FALSE;
}
- *result = kBlockLengthPrefixCode[index].offset + bits;
+ *result = offset + bits;
s->substate_read_block_length = BROTLI_STATE_READ_BLOCK_LENGTH_NONE;
return BROTLI_TRUE;
}
@@ -952,22 +961,22 @@ static BROTLI_NOINLINE void InverseMoveToFrontTransform(
/* Decodes a series of Huffman table using ReadHuffmanCode function. */
static BrotliDecoderErrorCode HuffmanTreeGroupDecode(
HuffmanTreeGroup* group, BrotliDecoderState* s) {
- if (s->substate_tree_group != BROTLI_STATE_TREE_GROUP_LOOP) {
- s->next = group->codes;
- s->htree_index = 0;
- s->substate_tree_group = BROTLI_STATE_TREE_GROUP_LOOP;
+ BrotliMetablockHeaderArena* h = &s->arena.header;
+ if (h->substate_tree_group != BROTLI_STATE_TREE_GROUP_LOOP) {
+ h->next = group->codes;
+ h->htree_index = 0;
+ h->substate_tree_group = BROTLI_STATE_TREE_GROUP_LOOP;
}
- while (s->htree_index < group->num_htrees) {
+ while (h->htree_index < group->num_htrees) {
uint32_t table_size;
- BrotliDecoderErrorCode result =
- ReadHuffmanCode(group->alphabet_size, group->max_symbol,
- s->next, &table_size, s);
+ BrotliDecoderErrorCode result = ReadHuffmanCode(group->alphabet_size_max,
+ group->alphabet_size_limit, h->next, &table_size, s);
if (result != BROTLI_DECODER_SUCCESS) return result;
- group->htrees[s->htree_index] = s->next;
- s->next += table_size;
- ++s->htree_index;
+ group->htrees[h->htree_index] = h->next;
+ h->next += table_size;
+ ++h->htree_index;
}
- s->substate_tree_group = BROTLI_STATE_TREE_GROUP_NONE;
+ h->substate_tree_group = BROTLI_STATE_TREE_GROUP_NONE;
return BROTLI_DECODER_SUCCESS;
}
@@ -985,15 +994,16 @@ static BrotliDecoderErrorCode DecodeContextMap(uint32_t context_map_size,
BrotliDecoderState* s) {
BrotliBitReader* br = &s->br;
BrotliDecoderErrorCode result = BROTLI_DECODER_SUCCESS;
+ BrotliMetablockHeaderArena* h = &s->arena.header;
- switch ((int)s->substate_context_map) {
+ switch ((int)h->substate_context_map) {
case BROTLI_STATE_CONTEXT_MAP_NONE:
result = DecodeVarLenUint8(s, br, num_htrees);
if (result != BROTLI_DECODER_SUCCESS) {
return result;
}
(*num_htrees)++;
- s->context_index = 0;
+ h->context_index = 0;
BROTLI_LOG_UINT(context_map_size);
BROTLI_LOG_UINT(*num_htrees);
*context_map_arg =
@@ -1005,7 +1015,7 @@ static BrotliDecoderErrorCode DecodeContextMap(uint32_t context_map_size,
memset(*context_map_arg, 0, (size_t)context_map_size);
return BROTLI_DECODER_SUCCESS;
}
- s->substate_context_map = BROTLI_STATE_CONTEXT_MAP_READ_PREFIX;
+ h->substate_context_map = BROTLI_STATE_CONTEXT_MAP_READ_PREFIX;
/* Fall through. */
case BROTLI_STATE_CONTEXT_MAP_READ_PREFIX: {
@@ -1016,38 +1026,38 @@ static BrotliDecoderErrorCode DecodeContextMap(uint32_t context_map_size,
return BROTLI_DECODER_NEEDS_MORE_INPUT;
}
if ((bits & 1) != 0) { /* Use RLE for zeros. */
- s->max_run_length_prefix = (bits >> 1) + 1;
+ h->max_run_length_prefix = (bits >> 1) + 1;
BrotliDropBits(br, 5);
} else {
- s->max_run_length_prefix = 0;
+ h->max_run_length_prefix = 0;
BrotliDropBits(br, 1);
}
- BROTLI_LOG_UINT(s->max_run_length_prefix);
- s->substate_context_map = BROTLI_STATE_CONTEXT_MAP_HUFFMAN;
+ BROTLI_LOG_UINT(h->max_run_length_prefix);
+ h->substate_context_map = BROTLI_STATE_CONTEXT_MAP_HUFFMAN;
}
/* Fall through. */
case BROTLI_STATE_CONTEXT_MAP_HUFFMAN: {
- uint32_t alphabet_size = *num_htrees + s->max_run_length_prefix;
+ uint32_t alphabet_size = *num_htrees + h->max_run_length_prefix;
result = ReadHuffmanCode(alphabet_size, alphabet_size,
- s->context_map_table, NULL, s);
+ h->context_map_table, NULL, s);
if (result != BROTLI_DECODER_SUCCESS) return result;
- s->code = 0xFFFF;
- s->substate_context_map = BROTLI_STATE_CONTEXT_MAP_DECODE;
+ h->code = 0xFFFF;
+ h->substate_context_map = BROTLI_STATE_CONTEXT_MAP_DECODE;
}
/* Fall through. */
case BROTLI_STATE_CONTEXT_MAP_DECODE: {
- uint32_t context_index = s->context_index;
- uint32_t max_run_length_prefix = s->max_run_length_prefix;
+ uint32_t context_index = h->context_index;
+ uint32_t max_run_length_prefix = h->max_run_length_prefix;
uint8_t* context_map = *context_map_arg;
- uint32_t code = s->code;
+ uint32_t code = h->code;
BROTLI_BOOL skip_preamble = (code != 0xFFFF);
while (context_index < context_map_size || skip_preamble) {
if (!skip_preamble) {
- if (!SafeReadSymbol(s->context_map_table, br, &code)) {
- s->code = 0xFFFF;
- s->context_index = context_index;
+ if (!SafeReadSymbol(h->context_map_table, br, &code)) {
+ h->code = 0xFFFF;
+ h->context_index = context_index;
return BROTLI_DECODER_NEEDS_MORE_INPUT;
}
BROTLI_LOG_UINT(code);
@@ -1068,8 +1078,8 @@ static BrotliDecoderErrorCode DecodeContextMap(uint32_t context_map_size,
{
uint32_t reps;
if (!BrotliSafeReadBits(br, code, &reps)) {
- s->code = code;
- s->context_index = context_index;
+ h->code = code;
+ h->context_index = context_index;
return BROTLI_DECODER_NEEDS_MORE_INPUT;
}
reps += 1U << code;
@@ -1089,13 +1099,13 @@ static BrotliDecoderErrorCode DecodeContextMap(uint32_t context_map_size,
case BROTLI_STATE_CONTEXT_MAP_TRANSFORM: {
uint32_t bits;
if (!BrotliSafeReadBits(br, 1, &bits)) {
- s->substate_context_map = BROTLI_STATE_CONTEXT_MAP_TRANSFORM;
+ h->substate_context_map = BROTLI_STATE_CONTEXT_MAP_TRANSFORM;
return BROTLI_DECODER_NEEDS_MORE_INPUT;
}
if (bits != 0) {
InverseMoveToFrontTransform(*context_map_arg, context_map_size, s);
}
- s->substate_context_map = BROTLI_STATE_CONTEXT_MAP_NONE;
+ h->substate_context_map = BROTLI_STATE_CONTEXT_MAP_NONE;
return BROTLI_DECODER_SUCCESS;
}
@@ -1457,32 +1467,28 @@ static BrotliDecoderErrorCode ReadContextModes(BrotliDecoderState* s) {
}
static BROTLI_INLINE void TakeDistanceFromRingBuffer(BrotliDecoderState* s) {
- if (s->distance_code == 0) {
- --s->dist_rb_idx;
- s->distance_code = s->dist_rb[s->dist_rb_idx & 3];
+ int offset = s->distance_code - 3;
+ if (s->distance_code <= 3) {
/* Compensate double distance-ring-buffer roll for dictionary items. */
- s->distance_context = 1;
+ s->distance_context = 1 >> s->distance_code;
+ s->distance_code = s->dist_rb[(s->dist_rb_idx - offset) & 3];
+ s->dist_rb_idx -= s->distance_context;
} 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;
- int v = (s->dist_rb_idx +
- (int)(kDistanceShortCodeIndexOffset >> distance_code)) & 0x3;
- s->distance_code = s->dist_rb[v];
- v = (int)(kDistanceShortCodeValueOffset >> distance_code) & 0x3;
- if ((distance_code & 0x3) != 0) {
- s->distance_code += v;
+ int index_delta = 3;
+ int delta;
+ int base = s->distance_code - 10;
+ if (s->distance_code < 10) {
+ base = s->distance_code - 4;
} 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 = 0x7FFFFFFF;
- }
+ index_delta = 2;
+ }
+ /* Unpack one of six 4-bit values. */
+ delta = ((0x605142 >> (4 * base)) & 0xF) - 3;
+ s->distance_code = s->dist_rb[(s->dist_rb_idx + index_delta) & 0x3] + delta;
+ 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 = 0x7FFFFFFF;
}
}
}
@@ -1497,62 +1503,153 @@ static BROTLI_INLINE BROTLI_BOOL SafeReadBits(
}
}
+static BROTLI_INLINE BROTLI_BOOL SafeReadBits32(
+ BrotliBitReader* const br, uint32_t n_bits, uint32_t* val) {
+ if (n_bits != 0) {
+ return BrotliSafeReadBits32(br, n_bits, val);
+ } else {
+ *val = 0;
+ return BROTLI_TRUE;
+ }
+}
+
+/*
+ RFC 7932 Section 4 with "..." shortenings and "[]" emendations.
+
+ Each distance ... is represented with a pair <distance code, extra bits>...
+ The distance code is encoded using a prefix code... The number of extra bits
+ can be 0..24... Two additional parameters: NPOSTFIX (0..3), and ...
+ NDIRECT (0..120) ... are encoded in the meta-block header...
+
+ The first 16 distance symbols ... reference past distances... ring buffer ...
+ Next NDIRECT distance symbols ... represent distances from 1 to NDIRECT...
+ [For] distance symbols 16 + NDIRECT and greater ... the number of extra bits
+ ... is given by the following formula:
+
+ [ xcode = dcode - NDIRECT - 16 ]
+ ndistbits = 1 + [ xcode ] >> (NPOSTFIX + 1)
+
+ ...
+*/
+
+/*
+ RFC 7932 Section 9.2 with "..." shortenings and "[]" emendations.
+
+ ... to get the actual value of the parameter NDIRECT, left-shift this
+ four-bit number by NPOSTFIX bits ...
+*/
+
+/* Remaining formulas from RFC 7932 Section 4 could be rewritten as following:
+
+ alphabet_size = 16 + NDIRECT + (max_distbits << (NPOSTFIX + 1))
+
+ half = ((xcode >> NPOSTFIX) & 1) << ndistbits
+ postfix = xcode & ((1 << NPOSTFIX) - 1)
+ range_start = 2 * (1 << ndistbits - 1 - 1)
+
+ distance = (range_start + half + extra) << NPOSTFIX + postfix + NDIRECT + 1
+
+ NB: ndistbits >= 1 -> range_start >= 0
+ NB: range_start has factor 2, as the range is covered by 2 "halves"
+ NB: extra -1 offset in range_start formula covers the absence of
+ ndistbits = 0 case
+ NB: when NPOSTFIX = 0, NDIRECT is not greater than 15
+
+ In other words, xcode has the following binary structure - XXXHPPP:
+ - XXX represent the number of extra distance bits
+ - H selects upper / lower range of distances
+ - PPP represent "postfix"
+
+ "Regular" distance encoding has NPOSTFIX = 0; omitting the postfix part
+ simplifies distance calculation.
+
+ Using NPOSTFIX > 0 allows cheaper encoding of regular structures, e.g. where
+ most of distances have the same reminder of division by 2/4/8. For example,
+ the table of int32_t values that come from different sources; if it is likely
+ that 3 highest bytes of values from the same source are the same, then
+ copy distance often looks like 4x + y.
+
+ Distance calculation could be rewritten to:
+
+ ndistbits = NDISTBITS(NDIRECT, NPOSTFIX)[dcode]
+ distance = OFFSET(NDIRECT, NPOSTFIX)[dcode] + extra << NPOSTFIX
+
+ NDISTBITS and OFFSET could be pre-calculated, as NDIRECT and NPOSTFIX could
+ change only once per meta-block.
+*/
+
+/* Calculates distance lookup table.
+ NB: it is possible to have all 64 tables precalculated. */
+static void CalculateDistanceLut(BrotliDecoderState* s) {
+ BrotliMetablockBodyArena* b = &s->arena.body;
+ uint32_t npostfix = s->distance_postfix_bits;
+ uint32_t ndirect = s->num_direct_distance_codes;
+ uint32_t alphabet_size_limit = s->distance_hgroup.alphabet_size_limit;
+ uint32_t postfix = 1u << npostfix;
+ uint32_t j;
+ uint32_t bits = 1;
+ uint32_t half = 0;
+
+ /* Skip short codes. */
+ uint32_t i = BROTLI_NUM_DISTANCE_SHORT_CODES;
+
+ /* Fill direct codes. */
+ for (j = 0; j < ndirect; ++j) {
+ b->dist_extra_bits[i] = 0;
+ b->dist_offset[i] = j + 1;
+ ++i;
+ }
+
+ /* Fill regular distance codes. */
+ while (i < alphabet_size_limit) {
+ uint32_t base = ndirect + ((((2 + half) << bits) - 4) << npostfix) + 1;
+ /* Always fill the complete group. */
+ for (j = 0; j < postfix; ++j) {
+ b->dist_extra_bits[i] = (uint8_t)bits;
+ b->dist_offset[i] = base + j;
+ ++i;
+ }
+ bits = bits + half;
+ half = half ^ 1;
+ }
+}
+
/* Precondition: s->distance_code < 0. */
static BROTLI_INLINE BROTLI_BOOL ReadDistanceInternal(
int safe, BrotliDecoderState* s, BrotliBitReader* br) {
- int distval;
+ BrotliMetablockBodyArena* b = &s->arena.body;
+ uint32_t code;
+ uint32_t bits;
BrotliBitReaderState memento;
HuffmanCode* distance_tree = s->distance_hgroup.htrees[s->dist_htree_index];
if (!safe) {
- s->distance_code = (int)ReadSymbol(distance_tree, br);
+ code = ReadSymbol(distance_tree, br);
} else {
- uint32_t code;
BrotliBitReaderSaveState(br, &memento);
if (!SafeReadSymbol(distance_tree, br, &code)) {
return BROTLI_FALSE;
}
- s->distance_code = (int)code;
}
+ --s->block_length[2];
/* Convert the distance code to the actual distance by possibly
- looking up past distances from the s->ringbuffer. */
+ looking up past distances from the s->dist_rb. */
s->distance_context = 0;
- if ((s->distance_code & ~0xF) == 0) {
+ if ((code & ~0xFu) == 0) {
+ s->distance_code = (int)code;
TakeDistanceFromRingBuffer(s);
- --s->block_length[2];
return BROTLI_TRUE;
}
- distval = s->distance_code - (int)s->num_direct_distance_codes;
- if (distval >= 0) {
- uint32_t nbits;
- int postfix;
- int offset;
- if (!safe && (s->distance_postfix_bits == 0)) {
- nbits = ((uint32_t)distval >> 1) + 1;
- offset = ((2 + (distval & 1)) << nbits) - 4;
- 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. */
- 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. */
- BrotliBitReaderRestoreState(br, &memento);
- return BROTLI_FALSE;
- }
- } else {
- bits = BrotliReadBits(br, nbits);
- }
- offset = ((2 + (distval & 1)) << nbits) - 4;
- s->distance_code = (int)s->num_direct_distance_codes +
- ((offset + (int)bits) << s->distance_postfix_bits) + postfix;
+ if (!safe) {
+ bits = BrotliReadBits32(br, b->dist_extra_bits[code]);
+ } else {
+ if (!SafeReadBits32(br, b->dist_extra_bits[code], &bits)) {
+ ++s->block_length[2];
+ BrotliBitReaderRestoreState(br, &memento);
+ return BROTLI_FALSE;
}
}
- s->distance_code = s->distance_code - BROTLI_NUM_DISTANCE_SHORT_CODES + 1;
- --s->block_length[2];
+ s->distance_code =
+ (int)(b->dist_offset[code] + (bits << s->distance_postfix_bits));
return BROTLI_TRUE;
}
@@ -1588,9 +1685,9 @@ static BROTLI_INLINE BROTLI_BOOL ReadCommandInternal(
*insert_length = v.insert_len_offset;
if (!safe) {
if (BROTLI_PREDICT_FALSE(v.insert_len_extra_bits != 0)) {
- insert_len_extra = BrotliReadBits(br, v.insert_len_extra_bits);
+ insert_len_extra = BrotliReadBits24(br, v.insert_len_extra_bits);
}
- copy_length = BrotliReadBits(br, v.copy_len_extra_bits);
+ copy_length = BrotliReadBits24(br, v.copy_len_extra_bits);
} else {
if (!SafeReadBits(br, v.insert_len_extra_bits, &insert_len_extra) ||
!SafeReadBits(br, v.copy_len_extra_bits, &copy_length)) {
@@ -1935,21 +2032,6 @@ 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) {
@@ -2167,33 +2249,23 @@ BrotliDecoderResult BrotliDecoderDecompressStream(
s->state = BROTLI_STATE_UNCOMPRESSED;
break;
}
+ s->state = BROTLI_STATE_BEFORE_COMPRESSED_METABLOCK_HEADER;
+ /* Fall through. */
+
+ case BROTLI_STATE_BEFORE_COMPRESSED_METABLOCK_HEADER: {
+ BrotliMetablockHeaderArena* h = &s->arena.header;
s->loop_counter = 0;
+ /* Initialize compressed metablock header arena. */
+ h->sub_loop_counter = 0;
+ /* Make small negative indexes addressable. */
+ h->symbol_lists =
+ &h->symbols_lists_array[BROTLI_HUFFMAN_MAX_CODE_LENGTH + 1];
+ h->substate_huffman = BROTLI_STATE_HUFFMAN_NONE;
+ h->substate_tree_group = BROTLI_STATE_TREE_GROUP_NONE;
+ h->substate_context_map = BROTLI_STATE_CONTEXT_MAP_NONE;
s->state = BROTLI_STATE_HUFFMAN_CODE_0;
- break;
-
- case BROTLI_STATE_UNCOMPRESSED: {
- result = CopyUncompressedBlockToOutput(
- available_out, next_out, total_out, s);
- if (result != BROTLI_DECODER_SUCCESS) {
- break;
- }
- 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;
- /* Read one byte and ignore it. */
- if (!BrotliSafeReadBits(br, 8, &bits)) {
- result = BROTLI_DECODER_NEEDS_MORE_INPUT;
- break;
- }
- }
- if (result == BROTLI_DECODER_SUCCESS) {
- s->state = BROTLI_STATE_METABLOCK_DONE;
- }
- break;
+ /* Fall through. */
case BROTLI_STATE_HUFFMAN_CODE_0:
if (s->loop_counter >= 3) {
@@ -2247,6 +2319,30 @@ BrotliDecoderResult BrotliDecoderDecompressStream(
break;
}
+ case BROTLI_STATE_UNCOMPRESSED: {
+ result = CopyUncompressedBlockToOutput(
+ available_out, next_out, total_out, s);
+ if (result != BROTLI_DECODER_SUCCESS) {
+ break;
+ }
+ 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;
+ /* Read one byte and ignore it. */
+ if (!BrotliSafeReadBits(br, 8, &bits)) {
+ result = BROTLI_DECODER_NEEDS_MORE_INPUT;
+ break;
+ }
+ }
+ if (result == BROTLI_DECODER_SUCCESS) {
+ s->state = BROTLI_STATE_METABLOCK_DONE;
+ }
+ break;
+
case BROTLI_STATE_METABLOCK_HEADER_2: {
uint32_t bits;
if (!BrotliSafeReadBits(br, 6, &bits)) {
@@ -2255,11 +2351,9 @@ BrotliDecoderResult BrotliDecoderDecompressStream(
}
s->distance_postfix_bits = bits & BitMask(2);
bits >>= 2;
- s->num_direct_distance_codes = BROTLI_NUM_DISTANCE_SHORT_CODES +
- (bits << s->distance_postfix_bits);
+ s->num_direct_distance_codes = bits << s->distance_postfix_bits;
BROTLI_LOG_UINT(s->num_direct_distance_codes);
BROTLI_LOG_UINT(s->distance_postfix_bits);
- s->distance_postfix_mask = (int)BitMask(s->distance_postfix_bits);
s->context_modes =
(uint8_t*)BROTLI_DECODER_ALLOC(s, (size_t)s->num_block_types[0]);
if (s->context_modes == 0) {
@@ -2291,17 +2385,19 @@ BrotliDecoderResult BrotliDecoderDecompressStream(
/* Fall through. */
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(
- s->distance_postfix_bits, num_direct_codes,
- (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);
+ uint32_t npostfix = s->distance_postfix_bits;
+ uint32_t ndirect = s->num_direct_distance_codes;
+ uint32_t distance_alphabet_size_max = BROTLI_DISTANCE_ALPHABET_SIZE(
+ npostfix, ndirect, BROTLI_MAX_DISTANCE_BITS);
+ uint32_t distance_alphabet_size_limit = distance_alphabet_size_max;
BROTLI_BOOL allocation_success = BROTLI_TRUE;
+ if (s->large_window) {
+ BrotliDistanceCodeLimit limit = BrotliCalculateDistanceCodeLimit(
+ BROTLI_MAX_ALLOWED_DISTANCE, npostfix, ndirect);
+ distance_alphabet_size_max = BROTLI_DISTANCE_ALPHABET_SIZE(
+ npostfix, ndirect, BROTLI_LARGE_MAX_DISTANCE_BITS);
+ distance_alphabet_size_limit = limit.max_alphabet_size;
+ }
result = DecodeContextMap(
s->num_block_types[2] << BROTLI_DISTANCE_CONTEXT_BITS,
&s->num_dist_htrees, &s->dist_context_map, s);
@@ -2315,8 +2411,8 @@ BrotliDecoderResult BrotliDecoderDecompressStream(
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);
+ s, &s->distance_hgroup, distance_alphabet_size_max,
+ distance_alphabet_size_limit, s->num_dist_htrees);
if (!allocation_success) {
return SaveErrorCode(s,
BROTLI_FAILURE(BROTLI_DECODER_ERROR_ALLOC_TREE_GROUPS));
@@ -2338,18 +2434,24 @@ BrotliDecoderResult BrotliDecoderDecompressStream(
result = HuffmanTreeGroupDecode(hgroup, s);
if (result != BROTLI_DECODER_SUCCESS) break;
s->loop_counter++;
- if (s->loop_counter >= 3) {
- PrepareLiteralDecoding(s);
- s->dist_context_map_slice = s->dist_context_map;
- s->htree_command = s->insert_copy_hgroup.htrees[0];
- if (!BrotliEnsureRingBuffer(s)) {
- result = BROTLI_FAILURE(BROTLI_DECODER_ERROR_ALLOC_RING_BUFFER_2);
- break;
- }
- s->state = BROTLI_STATE_COMMAND_BEGIN;
+ if (s->loop_counter < 3) {
+ break;
}
- break;
+ s->state = BROTLI_STATE_BEFORE_COMPRESSED_METABLOCK_BODY;
}
+ /* Fall through. */
+
+ case BROTLI_STATE_BEFORE_COMPRESSED_METABLOCK_BODY:
+ PrepareLiteralDecoding(s);
+ s->dist_context_map_slice = s->dist_context_map;
+ s->htree_command = s->insert_copy_hgroup.htrees[0];
+ if (!BrotliEnsureRingBuffer(s)) {
+ result = BROTLI_FAILURE(BROTLI_DECODER_ERROR_ALLOC_RING_BUFFER_2);
+ break;
+ }
+ CalculateDistanceLut(s);
+ s->state = BROTLI_STATE_COMMAND_BEGIN;
+ /* Fall through. */
case BROTLI_STATE_COMMAND_BEGIN:
/* Fall through. */
diff --git a/modules/brotli/dec/huffman.h b/modules/brotli/dec/huffman.h
index b9f0716c1..a8fbc4534 100644
--- a/modules/brotli/dec/huffman.h
+++ b/modules/brotli/dec/huffman.h
@@ -18,12 +18,6 @@ extern "C" {
#define BROTLI_HUFFMAN_MAX_CODE_LENGTH 15
-/* Maximum possible Huffman table size for an alphabet size of (index * 32),
- max code length 15 and root table bits 8. */
-static const uint16_t kMaxHuffmanTableSize[] = {
- 256, 402, 436, 468, 500, 534, 566, 598, 630, 662, 694, 726, 758, 790, 822,
- 854, 886, 920, 952, 984, 1016, 1048, 1080, 1112, 1144, 1176, 1208, 1240, 1272,
- 1304, 1336, 1368, 1400, 1432, 1464, 1496, 1528};
/* BROTLI_NUM_BLOCK_LEN_SYMBOLS == 26 */
#define BROTLI_HUFFMAN_MAX_SIZE_26 396
/* BROTLI_MAX_BLOCK_TYPE_SYMBOLS == 258 */
@@ -82,7 +76,7 @@ typedef BROTLI_ALIGNED(4) uint32_t HuffmanCode;
static BROTLI_INLINE HuffmanCode ConstructHuffmanCode(const uint8_t bits,
const uint16_t value) {
- return ((value & 0xFFFF) << 16) | (bits & 0xFF);
+ return (HuffmanCode) ((value & 0xFFFF) << 16) | (bits & 0xFF);
}
#define BROTLI_HC_MARK_TABLE_FOR_FAST_LOAD(H) uint32_t __fastload_##H = (*H)
@@ -100,7 +94,7 @@ BROTLI_INTERNAL void BrotliBuildCodeLengthsHuffmanTable(HuffmanCode* root_table,
/* Builds Huffman lookup table assuming code lengths are in symbol order.
Returns size of resulting table. */
BROTLI_INTERNAL uint32_t BrotliBuildHuffmanTable(HuffmanCode* root_table,
- int root_bits, const uint16_t* const symbol_lists, uint16_t* count_arg);
+ int root_bits, const uint16_t* const symbol_lists, uint16_t* count);
/* Builds a simple Huffman table. The |num_symbols| parameter is to be
interpreted as follows: 0 means 1 symbol, 1 means 2 symbols,
@@ -110,13 +104,13 @@ BROTLI_INTERNAL uint32_t BrotliBuildSimpleHuffmanTable(HuffmanCode* table,
int root_bits, uint16_t* symbols, uint32_t num_symbols);
/* Contains a collection of Huffman trees with the same alphabet size. */
-/* max_symbol is needed due to simple codes since log2(alphabet_size) could be
- greater than log2(max_symbol). */
+/* alphabet_size_limit is needed due to simple codes, since
+ log2(alphabet_size_max) could be greater than log2(alphabet_size_limit). */
typedef struct {
HuffmanCode** htrees;
HuffmanCode* codes;
- uint16_t alphabet_size;
- uint16_t max_symbol;
+ uint16_t alphabet_size_max;
+ uint16_t alphabet_size_limit;
uint16_t num_htrees;
} HuffmanTreeGroup;
diff --git a/modules/brotli/dec/prefix.h b/modules/brotli/dec/prefix.h
index 3ea062d84..481a2c791 100644
--- a/modules/brotli/dec/prefix.h
+++ b/modules/brotli/dec/prefix.h
@@ -13,24 +13,6 @@
#include "../common/constants.h"
#include <brotli/types.h>
-/* Represents the range of values belonging to a prefix code:
- [offset, offset + 2^nbits) */
-struct PrefixCodeRange {
- uint16_t offset;
- uint8_t nbits;
-};
-
-static const struct PrefixCodeRange
- kBlockLengthPrefixCode[BROTLI_NUM_BLOCK_LEN_SYMBOLS] = {
- { 1, 2}, { 5, 2}, { 9, 2}, { 13, 2},
- { 17, 3}, { 25, 3}, { 33, 3}, { 41, 3},
- { 49, 4}, { 65, 4}, { 81, 4}, { 97, 4},
- { 113, 5}, { 145, 5}, { 177, 5}, { 209, 5},
- { 241, 6}, { 305, 6}, { 369, 7}, { 497, 8},
- { 753, 9}, { 1265, 10}, {2289, 11}, {4337, 12},
- {8433, 13}, {16625, 24}
-};
-
typedef struct CmdLutElement {
uint8_t insert_len_extra_bits;
uint8_t copy_len_extra_bits;
diff --git a/modules/brotli/dec/state.c b/modules/brotli/dec/state.c
index e0b37c2dc..f847836dd 100644
--- a/modules/brotli/dec/state.c
+++ b/modules/brotli/dec/state.c
@@ -33,10 +33,7 @@ BROTLI_BOOL BrotliDecoderStateInit(BrotliDecoderState* s,
s->state = BROTLI_STATE_UNINITED;
s->large_window = 0;
s->substate_metablock_header = BROTLI_STATE_METABLOCK_HEADER_NONE;
- s->substate_tree_group = BROTLI_STATE_TREE_GROUP_NONE;
- s->substate_context_map = BROTLI_STATE_CONTEXT_MAP_NONE;
s->substate_uncompressed = BROTLI_STATE_UNCOMPRESSED_NONE;
- s->substate_huffman = BROTLI_STATE_HUFFMAN_NONE;
s->substate_decode_uint8 = BROTLI_STATE_DECODE_UINT8_NONE;
s->substate_read_block_length = BROTLI_STATE_READ_BLOCK_LENGTH_NONE;
@@ -59,8 +56,6 @@ BROTLI_BOOL BrotliDecoderStateInit(BrotliDecoderState* s,
s->context_map_slice = NULL;
s->dist_context_map_slice = NULL;
- s->sub_loop_counter = 0;
-
s->literal_hgroup.codes = NULL;
s->literal_hgroup.htrees = NULL;
s->insert_copy_hgroup.codes = NULL;
@@ -84,9 +79,6 @@ BROTLI_BOOL BrotliDecoderStateInit(BrotliDecoderState* s,
s->block_type_trees = NULL;
s->block_len_trees = NULL;
- /* Make small negative indexes addressable. */
- s->symbol_lists = &s->symbols_lists_array[BROTLI_HUFFMAN_MAX_CODE_LENGTH + 1];
-
s->mtf_upper_bound = 63;
s->dictionary = BrotliGetDictionary();
@@ -142,17 +134,20 @@ void BrotliDecoderStateCleanup(BrotliDecoderState* s) {
}
BROTLI_BOOL BrotliDecoderHuffmanTreeGroupInit(BrotliDecoderState* s,
- HuffmanTreeGroup* group, uint32_t alphabet_size, uint32_t max_symbol,
- uint32_t ntrees) {
- /* Pack two allocations into one */
- const size_t max_table_size = kMaxHuffmanTableSize[(alphabet_size + 31) >> 5];
+ HuffmanTreeGroup* group, uint32_t alphabet_size_max,
+ uint32_t alphabet_size_limit, uint32_t ntrees) {
+ /* 376 = 256 (1-st level table) + 4 + 7 + 15 + 31 + 63 (2-nd level mix-tables)
+ This number is discovered "unlimited" "enough" calculator; it is actually
+ a wee bigger than required in several cases (especially for alphabets with
+ less than 16 symbols). */
+ const size_t max_table_size = alphabet_size_limit + 376;
const size_t code_size = sizeof(HuffmanCode) * ntrees * max_table_size;
const size_t htree_size = sizeof(HuffmanCode*) * ntrees;
/* Pointer alignment is, hopefully, wider than sizeof(HuffmanCode). */
HuffmanCode** p = (HuffmanCode**)BROTLI_DECODER_ALLOC(s,
code_size + htree_size);
- group->alphabet_size = (uint16_t)alphabet_size;
- group->max_symbol = (uint16_t)max_symbol;
+ group->alphabet_size_max = (uint16_t)alphabet_size_max;
+ group->alphabet_size_limit = (uint16_t)alphabet_size_limit;
group->num_htrees = (uint16_t)ntrees;
group->htrees = p;
group->codes = (HuffmanCode*)(&p[ntrees]);
diff --git a/modules/brotli/dec/state.h b/modules/brotli/dec/state.h
index d28b63920..54dab698b 100644
--- a/modules/brotli/dec/state.h
+++ b/modules/brotli/dec/state.h
@@ -21,6 +21,95 @@
extern "C" {
#endif
+/* Graphviz diagram that describes state transitions:
+
+digraph States {
+ graph [compound=true]
+ concentrate=true
+ node [shape="box"]
+
+ UNINITED -> {LARGE_WINDOW_BITS -> INITIALIZE}
+ subgraph cluster_metablock_workflow {
+ style="rounded"
+ label=< <B>METABLOCK CYCLE</B> >
+ METABLOCK_BEGIN -> METABLOCK_HEADER
+ METABLOCK_HEADER:sw -> METADATA
+ METABLOCK_HEADER:s -> UNCOMPRESSED
+ METABLOCK_HEADER:se -> METABLOCK_DONE:ne
+ METADATA:s -> METABLOCK_DONE:w
+ UNCOMPRESSED:s -> METABLOCK_DONE:n
+ METABLOCK_DONE:e -> METABLOCK_BEGIN:e [constraint="false"]
+ }
+ INITIALIZE -> METABLOCK_BEGIN
+ METABLOCK_DONE -> DONE
+
+ subgraph cluster_compressed_metablock {
+ style="rounded"
+ label=< <B>COMPRESSED METABLOCK</B> >
+
+ subgraph cluster_command {
+ style="rounded"
+ label=< <B>HOT LOOP</B> >
+
+ _METABLOCK_DONE_PORT_ [shape=point style=invis]
+
+ {
+ // Set different shape for nodes returning from "compressed metablock".
+ node [shape=invhouse]; CMD_INNER CMD_POST_DECODE_LITERALS;
+ CMD_POST_WRAP_COPY; CMD_INNER_WRITE; CMD_POST_WRITE_1;
+ }
+
+ CMD_BEGIN -> CMD_INNER -> CMD_POST_DECODE_LITERALS -> CMD_POST_WRAP_COPY
+
+ // IO ("write") nodes are not in the hot loop!
+ CMD_INNER_WRITE [style=dashed]
+ CMD_INNER -> CMD_INNER_WRITE
+ CMD_POST_WRITE_1 [style=dashed]
+ CMD_POST_DECODE_LITERALS -> CMD_POST_WRITE_1
+ CMD_POST_WRITE_2 [style=dashed]
+ CMD_POST_WRAP_COPY -> CMD_POST_WRITE_2
+
+ CMD_POST_WRITE_1 -> CMD_BEGIN:s [constraint="false"]
+ CMD_INNER_WRITE -> {CMD_INNER CMD_POST_DECODE_LITERALS}
+ [constraint="false"]
+ CMD_BEGIN:ne -> CMD_POST_DECODE_LITERALS [constraint="false"]
+ CMD_POST_WRAP_COPY -> CMD_BEGIN [constraint="false"]
+ CMD_POST_DECODE_LITERALS -> CMD_BEGIN:ne [constraint="false"]
+ CMD_POST_WRITE_2 -> CMD_POST_WRAP_COPY [constraint="false"]
+ {rank=same; CMD_BEGIN; CMD_INNER; CMD_POST_DECODE_LITERALS;
+ CMD_POST_WRAP_COPY}
+ {rank=same; CMD_INNER_WRITE; CMD_POST_WRITE_1; CMD_POST_WRITE_2}
+
+ {CMD_INNER CMD_POST_DECODE_LITERALS CMD_POST_WRAP_COPY} ->
+ _METABLOCK_DONE_PORT_ [style=invis]
+ {CMD_INNER_WRITE CMD_POST_WRITE_1} -> _METABLOCK_DONE_PORT_
+ [constraint="false" style=invis]
+ }
+
+ BEFORE_COMPRESSED_METABLOCK_HEADER:s -> HUFFMAN_CODE_0:n
+ HUFFMAN_CODE_0 -> HUFFMAN_CODE_1 -> HUFFMAN_CODE_2 -> HUFFMAN_CODE_3
+ HUFFMAN_CODE_0 -> METABLOCK_HEADER_2 -> CONTEXT_MODES -> CONTEXT_MAP_1
+ CONTEXT_MAP_1 -> CONTEXT_MAP_2 -> TREE_GROUP
+ TREE_GROUP -> BEFORE_COMPRESSED_METABLOCK_BODY:e
+ BEFORE_COMPRESSED_METABLOCK_BODY:s -> CMD_BEGIN:n
+
+ HUFFMAN_CODE_3:e -> HUFFMAN_CODE_0:ne [constraint="false"]
+ {rank=same; HUFFMAN_CODE_0; HUFFMAN_CODE_1; HUFFMAN_CODE_2; HUFFMAN_CODE_3}
+ {rank=same; METABLOCK_HEADER_2; CONTEXT_MODES; CONTEXT_MAP_1; CONTEXT_MAP_2;
+ TREE_GROUP}
+ }
+ METABLOCK_HEADER:e -> BEFORE_COMPRESSED_METABLOCK_HEADER:n
+
+ _METABLOCK_DONE_PORT_ -> METABLOCK_DONE:se
+ [constraint="false" ltail=cluster_command]
+
+ UNINITED [shape=Mdiamond];
+ DONE [shape=Msquare];
+}
+
+
+ */
+
typedef enum {
BROTLI_STATE_UNINITED,
BROTLI_STATE_LARGE_WINDOW_BITS,
@@ -39,6 +128,7 @@ typedef enum {
BROTLI_STATE_METABLOCK_DONE,
BROTLI_STATE_COMMAND_POST_WRITE_1,
BROTLI_STATE_COMMAND_POST_WRITE_2,
+ BROTLI_STATE_BEFORE_COMPRESSED_METABLOCK_HEADER,
BROTLI_STATE_HUFFMAN_CODE_0,
BROTLI_STATE_HUFFMAN_CODE_1,
BROTLI_STATE_HUFFMAN_CODE_2,
@@ -46,6 +136,7 @@ typedef enum {
BROTLI_STATE_CONTEXT_MAP_1,
BROTLI_STATE_CONTEXT_MAP_2,
BROTLI_STATE_TREE_GROUP,
+ BROTLI_STATE_BEFORE_COMPRESSED_METABLOCK_BODY,
BROTLI_STATE_DONE
} BrotliRunningState;
@@ -98,6 +189,50 @@ typedef enum {
BROTLI_STATE_READ_BLOCK_LENGTH_SUFFIX
} BrotliRunningReadBlockLengthState;
+typedef struct BrotliMetablockHeaderArena {
+ BrotliRunningTreeGroupState substate_tree_group;
+ BrotliRunningContextMapState substate_context_map;
+ BrotliRunningHuffmanState substate_huffman;
+
+ uint32_t sub_loop_counter;
+
+ uint32_t repeat_code_len;
+ uint32_t prev_code_len;
+
+ /* For ReadHuffmanCode. */
+ uint32_t symbol;
+ uint32_t repeat;
+ uint32_t space;
+
+ /* Huffman table for "histograms". */
+ HuffmanCode table[32];
+ /* List of heads of symbol chains. */
+ uint16_t* symbol_lists;
+ /* Storage from symbol_lists. */
+ uint16_t symbols_lists_array[BROTLI_HUFFMAN_MAX_CODE_LENGTH + 1 +
+ BROTLI_NUM_COMMAND_SYMBOLS];
+ /* Tails of symbol chains. */
+ int next_symbol[32];
+ uint8_t code_length_code_lengths[BROTLI_CODE_LENGTH_CODES];
+ /* Population counts for the code lengths. */
+ uint16_t code_length_histo[16];
+
+ /* For HuffmanTreeGroupDecode. */
+ int htree_index;
+ HuffmanCode* next;
+
+ /* For DecodeContextMap. */
+ uint32_t context_index;
+ uint32_t max_run_length_prefix;
+ uint32_t code;
+ HuffmanCode context_map_table[BROTLI_HUFFMAN_MAX_SIZE_272];
+} BrotliMetablockHeaderArena;
+
+typedef struct BrotliMetablockBodyArena {
+ uint8_t dist_extra_bits[544];
+ uint32_t dist_offset[544];
+} BrotliMetablockBodyArena;
+
struct BrotliDecoderStateStruct {
BrotliRunningState state;
@@ -110,7 +245,8 @@ struct BrotliDecoderStateStruct {
brotli_free_func free_func;
void* memory_manager_opaque;
- /* Temporary storage for remaining input. */
+ /* Temporary storage for remaining input. Brotli stream format is designed in
+ a way, that 64 bits are enough to make progress in decoding. */
union {
uint64_t u64;
uint8_t u8[8];
@@ -125,7 +261,6 @@ struct BrotliDecoderStateStruct {
int dist_rb_idx;
int dist_rb[4];
int error_code;
- uint32_t sub_loop_counter;
uint8_t* ringbuffer;
uint8_t* ringbuffer_end;
HuffmanCode* htree_command;
@@ -153,13 +288,10 @@ struct BrotliDecoderStateStruct {
uint32_t block_type_rb[6];
uint32_t distance_postfix_bits;
uint32_t num_direct_distance_codes;
- int distance_postfix_mask;
uint32_t num_dist_htrees;
uint8_t* dist_context_map;
HuffmanCode* literal_htree;
uint8_t dist_htree_index;
- uint32_t repeat_code_len;
- uint32_t prev_code_len;
int copy_length;
int distance_code;
@@ -168,33 +300,6 @@ struct BrotliDecoderStateStruct {
size_t rb_roundtrips; /* how many times we went around the ring-buffer */
size_t partial_pos_out; /* how much output to the user in total */
- /* For ReadHuffmanCode. */
- uint32_t symbol;
- uint32_t repeat;
- uint32_t space;
-
- HuffmanCode table[32];
- /* List of heads of symbol chains. */
- uint16_t* symbol_lists;
- /* Storage from symbol_lists. */
- uint16_t symbols_lists_array[BROTLI_HUFFMAN_MAX_CODE_LENGTH + 1 +
- BROTLI_NUM_COMMAND_SYMBOLS];
- /* Tails of symbol chains. */
- int next_symbol[32];
- uint8_t code_length_code_lengths[BROTLI_CODE_LENGTH_CODES];
- /* Population counts for the code lengths. */
- uint16_t code_length_histo[16];
-
- /* For HuffmanTreeGroupDecode. */
- int htree_index;
- HuffmanCode* next;
-
- /* For DecodeContextMap. */
- uint32_t context_index;
- uint32_t max_run_length_prefix;
- uint32_t code;
- HuffmanCode context_map_table[BROTLI_HUFFMAN_MAX_SIZE_272];
-
/* For InverseMoveToFrontTransform. */
uint32_t mtf_upper_bound;
uint32_t mtf[64 + 1];
@@ -203,10 +308,7 @@ struct BrotliDecoderStateStruct {
/* States inside function calls. */
BrotliRunningMetablockHeaderState substate_metablock_header;
- BrotliRunningTreeGroupState substate_tree_group;
- BrotliRunningContextMapState substate_context_map;
BrotliRunningUncompressedState substate_uncompressed;
- BrotliRunningHuffmanState substate_huffman;
BrotliRunningDecodeUint8State substate_decode_uint8;
BrotliRunningReadBlockLengthState substate_read_block_length;
@@ -229,6 +331,11 @@ struct BrotliDecoderStateStruct {
const BrotliTransforms* transforms;
uint32_t trivial_literal_contexts[8]; /* 256 bits */
+
+ union {
+ BrotliMetablockHeaderArena header;
+ BrotliMetablockBodyArena body;
+ } arena;
};
typedef struct BrotliDecoderStateStruct BrotliDecoderStateInternal;
@@ -241,8 +348,8 @@ BROTLI_INTERNAL void BrotliDecoderStateMetablockBegin(BrotliDecoderState* s);
BROTLI_INTERNAL void BrotliDecoderStateCleanupAfterMetablock(
BrotliDecoderState* s);
BROTLI_INTERNAL BROTLI_BOOL BrotliDecoderHuffmanTreeGroupInit(
- BrotliDecoderState* s, HuffmanTreeGroup* group, uint32_t alphabet_size,
- uint32_t max_symbol, uint32_t ntrees);
+ BrotliDecoderState* s, HuffmanTreeGroup* group, uint32_t alphabet_size_max,
+ uint32_t alphabet_size_limit, uint32_t ntrees);
#define BROTLI_DECODER_ALLOC(S, L) S->alloc_func(S->memory_manager_opaque, L)
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-08 10:41:53 +0000