/* Adds the next symbol to the current histogram. When the current histogram
* reaches the target size, decides on merging the block. */
public static unsafe void BlockSplitterAddSymbol(BlockSplitterDistance *self, size_t symbol)
{
HistogramDistance.HistogramAdd(&self->histograms_[self->curr_histogram_ix_], symbol);
++self->block_size_;
if (self->block_size_ == self->target_block_size_)
{
BlockSplitterFinishBlock(self, /* is_final = */ false);
}
}
private static unsafe void BrotliBuildHistogramsWithContext(
Command *cmds, size_t num_commands,
BlockSplit *literal_split, BlockSplit *insert_and_copy_split,
BlockSplit *dist_split, byte *ringbuffer, size_t start_pos,
size_t mask, byte prev_byte, byte prev_byte2,
ContextType *context_modes, HistogramLiteral *literal_histograms,
HistogramCommand *insert_and_copy_histograms,
HistogramDistance *copy_dist_histograms)
{
size_t pos = start_pos;
BlockSplitIterator literal_it;
BlockSplitIterator insert_and_copy_it;
BlockSplitIterator dist_it;
size_t i;
InitBlockSplitIterator(&literal_it, literal_split);
InitBlockSplitIterator(&insert_and_copy_it, insert_and_copy_split);
InitBlockSplitIterator(&dist_it, dist_split);
for (i = 0; i < num_commands; ++i)
{
Command *cmd = &cmds[i];
size_t j;
BlockSplitIteratorNext(&insert_and_copy_it);
HistogramCommand.HistogramAdd(&insert_and_copy_histograms[insert_and_copy_it.type_],
cmd->cmd_prefix_);
for (j = cmd->insert_len_; j != 0; --j)
{
size_t context;
BlockSplitIteratorNext(&literal_it);
context = context_modes != null ?
((literal_it.type_ << BROTLI_LITERAL_CONTEXT_BITS) +
Context(prev_byte, prev_byte2, context_modes[literal_it.type_])) :
literal_it.type_;
HistogramLiteral.HistogramAdd(&literal_histograms[context],
ringbuffer[pos & mask]);
prev_byte2 = prev_byte;
prev_byte = ringbuffer[pos & mask];
++pos;
}
pos += CommandCopyLen(cmd);
if (CommandCopyLen(cmd) != 0)
{
prev_byte2 = ringbuffer[(pos - 2) & mask];
prev_byte = ringbuffer[(pos - 1) & mask];
if (cmd->cmd_prefix_ >= 128)
{
size_t context;
BlockSplitIteratorNext(&dist_it);
context = (dist_it.type_ << BROTLI_DISTANCE_CONTEXT_BITS) +
CommandDistanceContext(cmd);
HistogramDistance.HistogramAdd(©_dist_histograms[context],
cmd->dist_prefix_);
}
}
}
}
