void BrotliHuffmanTreeGroupInit(BrotliState* s, HuffmanTreeGroup* group,
uint32_t alphabet_size, uint32_t ntrees) {
/* Pack two allocations into one */
const size_t code_size =
sizeof(HuffmanCode) * (size_t)(ntrees * BROTLI_HUFFMAN_MAX_TABLE_SIZE);
const size_t htree_size = sizeof(HuffmanCode*) * (size_t)ntrees;
char *p = (char*)BROTLI_ALLOC(s, code_size + htree_size);
group->alphabet_size = (uint16_t)alphabet_size;
group->num_htrees = (uint16_t)ntrees;
group->codes = (HuffmanCode*)p;
group->htrees = (HuffmanCode**)(p + code_size);
}
void BrotliHuffmanTreeGroupInit(BrotliState* s, HuffmanTreeGroup* group,
uint32_t alphabet_size, uint32_t ntrees) {
/* Pack two allocations into one */
const size_t max_table_size = kMaxHuffmanTableSize[(alphabet_size + 31) >> 5];
const size_t code_size = sizeof(HuffmanCode) * ntrees * max_table_size;
const size_t htree_size = sizeof(HuffmanCode*) * ntrees;
char* p = (char*)BROTLI_ALLOC(s, code_size + htree_size);
group->alphabet_size = (uint16_t)alphabet_size;
group->num_htrees = (uint16_t)ntrees;
group->codes = (HuffmanCode*)p;
group->htrees = (HuffmanCode**)(p + code_size);
}
void BrotliSplitBlock(MemoryManager* m,
const Command* cmds,
const size_t num_commands,
const uint8_t* data,
const size_t pos,
const size_t mask,
const BrotliEncoderParams* params,
BlockSplit* literal_split,
BlockSplit* insert_and_copy_split,
BlockSplit* dist_split) {
{
size_t literals_count = CountLiterals(cmds, num_commands);
uint8_t* literals = BROTLI_ALLOC(m, uint8_t, literals_count);
if (BROTLI_IS_OOM(m)) return;
/* Create a continuous array of literals. */
CopyLiteralsToByteArray(cmds, num_commands, data, pos, mask, literals);
/* Create the block split on the array of literals.
Literal histograms have alphabet size 256. */
SplitByteVectorLiteral(
m, literals, literals_count,
kSymbolsPerLiteralHistogram, kMaxLiteralHistograms,
kLiteralStrideLength, kLiteralBlockSwitchCost, params,
literal_split);
if (BROTLI_IS_OOM(m)) return;
BROTLI_FREE(m, literals);
}
{
/* Compute prefix codes for commands. */
uint16_t* insert_and_copy_codes = BROTLI_ALLOC(m, uint16_t, num_commands);
size_t i;
if (BROTLI_IS_OOM(m)) return;
for (i = 0; i < num_commands; ++i) {
insert_and_copy_codes[i] = cmds[i].cmd_prefix_;
}
/* Create the block split on the array of command prefixes. */
SplitByteVectorCommand(
m, insert_and_copy_codes, num_commands,
kSymbolsPerCommandHistogram, kMaxCommandHistograms,
kCommandStrideLength, kCommandBlockSwitchCost, params,
insert_and_copy_split);
if (BROTLI_IS_OOM(m)) return;
/* TODO: reuse for distances? */
BROTLI_FREE(m, insert_and_copy_codes);
}
{
/* Create a continuous array of distance prefixes. */
uint16_t* distance_prefixes = BROTLI_ALLOC(m, uint16_t, num_commands);
size_t j = 0;
size_t i;
if (BROTLI_IS_OOM(m)) return;
for (i = 0; i < num_commands; ++i) {
const Command* cmd = &cmds[i];
if (CommandCopyLen(cmd) && cmd->cmd_prefix_ >= 128) {
distance_prefixes[j++] = cmd->dist_prefix_;
}
}
/* Create the block split on the array of distance prefixes. */
SplitByteVectorDistance(
m, distance_prefixes, j,
kSymbolsPerDistanceHistogram, kMaxCommandHistograms,
kCommandStrideLength, kDistanceBlockSwitchCost, params,
dist_split);
if (BROTLI_IS_OOM(m)) return;
BROTLI_FREE(m, distance_prefixes);
}
}
