Apply suggestions from code review

Co-authored-by: Eugene Kliuchnikov <eustas@google.com>
This commit is contained in:
Mahesh Madhav 2024-11-12 14:45:06 -08:00 committed by Eugene Kliuchnikov
parent 1054ecc262
commit 782aadd0ff
2 changed files with 8 additions and 6 deletions

View File

@ -118,7 +118,8 @@ static size_t FN(FindBlocks)(const DataType* data, const size_t length,
size_t insert_cost_ix = symbol * num_histograms;
double min_cost = 1e99;
double block_switch_cost = block_switch_bitcost;
static const double threshold = 0.07 / 2000.0;
static const size_t prologue_length = 2000;
static const double multiplier = 0.07 / 2000;
size_t k;
for (k = 0; k < num_histograms; ++k) {
/* We are coding the symbol with entropy code k. */
@ -129,8 +130,8 @@ static size_t FN(FindBlocks)(const DataType* data, const size_t length,
}
}
/* More blocks for the beginning. */
if (byte_ix < 2000) {
block_switch_cost *= 0.77 + threshold * (double)byte_ix;
if (byte_ix < prologue_length) {
block_switch_cost *= 0.77 + multiplier * (double)byte_ix;
}
for (k = 0; k < num_histograms; ++k) {
cost[k] -= min_cost;

View File

@ -106,7 +106,8 @@ static void EstimateBitCostsForLiteralsUTF8(size_t pos, size_t len, size_t mask,
size_t utf8_pos = UTF8Position(last_c, c, max_utf8);
size_t masked_pos = (pos + i) & mask;
size_t histo = histogram[256 * utf8_pos + data[masked_pos]];
static const double threshold = 0.35 / 2000.0;
static const size_t prologue_length = 2000;
static const double multiplier = 0.35 / 2000;
double lit_cost;
if (histo == 0) {
histo = 1;
@ -121,8 +122,8 @@ static void EstimateBitCostsForLiteralsUTF8(size_t pos, size_t len, size_t mask,
Perhaps because the entropy source is changing its properties
rapidly in the beginning of the file, perhaps because the beginning
of the data is a statistical "anomaly". */
if (i < 2000) {
lit_cost += 0.7 - ((double)(2000 - i) * threshold);
if (i < prologue_length) {
lit_cost += 0.35 + multiplier * (double)i;
}
cost[i] = (float)lit_cost;
}