| /* Copyright 2013 Google Inc. All Rights Reserved. |
| |
| Distributed under MIT license. |
| See file LICENSE for detail or copy at https://opensource.org/licenses/MIT |
| */ |
| |
| /* Functions for clustering similar histograms together. */ |
| |
| #include "./cluster.h" |
| |
| #include "../common/platform.h" |
| #include <brotli/types.h> |
| #include "./bit_cost.h" /* BrotliPopulationCost */ |
| #include "./fast_log.h" |
| #include "./histogram.h" |
| #include "./memory.h" |
| |
| #if defined(__cplusplus) || defined(c_plusplus) |
| extern "C" { |
| #endif |
| |
| static BROTLI_INLINE BROTLI_BOOL HistogramPairIsLess( |
| const HistogramPair* p1, const HistogramPair* p2) { |
| if (p1->cost_diff != p2->cost_diff) { |
| return TO_BROTLI_BOOL(p1->cost_diff > p2->cost_diff); |
| } |
| return TO_BROTLI_BOOL((p1->idx2 - p1->idx1) > (p2->idx2 - p2->idx1)); |
| } |
| |
| /* Returns entropy reduction of the context map when we combine two clusters. */ |
| static BROTLI_INLINE double ClusterCostDiff(size_t size_a, size_t size_b) { |
| size_t size_c = size_a + size_b; |
| return (double)size_a * FastLog2(size_a) + |
| (double)size_b * FastLog2(size_b) - |
| (double)size_c * FastLog2(size_c); |
| } |
| |
| #define CODE(X) X |
| |
| #define FN(X) X ## Literal |
| #include "./cluster_inc.h" /* NOLINT(build/include) */ |
| #undef FN |
| |
| #define FN(X) X ## Command |
| #include "./cluster_inc.h" /* NOLINT(build/include) */ |
| #undef FN |
| |
| #define FN(X) X ## Distance |
| #include "./cluster_inc.h" /* NOLINT(build/include) */ |
| #undef FN |
| |
| #undef CODE |
| |
| #if defined(__cplusplus) || defined(c_plusplus) |
| } /* extern "C" */ |
| #endif |