744 static int HistoQueueInit(HistoQueue* const histo_queue, const int max_size) {  in HistoQueueInit()  argument
745   histo_queue->size = 0;  in HistoQueueInit()
746   histo_queue->max_size = max_size;  in HistoQueueInit()
749   histo_queue->queue = (HistogramPair*)WebPSafeMalloc(  in HistoQueueInit()
750       histo_queue->max_size + 1, sizeof(*histo_queue->queue));  in HistoQueueInit()
751   return histo_queue->queue != NULL;  in HistoQueueInit()
754 static void HistoQueueClear(HistoQueue* const histo_queue) {  in HistoQueueClear()  argument
755   assert(histo_queue != NULL);  in HistoQueueClear()
756   WebPSafeFree(histo_queue->queue);  in HistoQueueClear()
757   histo_queue->size = 0;  in HistoQueueClear()
758   histo_queue->max_size = 0;  in HistoQueueClear()
763 static void HistoQueuePopPair(HistoQueue* const histo_queue,  in HistoQueuePopPair()  argument
765   assert(pair >= histo_queue->queue &&  in HistoQueuePopPair()
766          pair < (histo_queue->queue + histo_queue->size));  in HistoQueuePopPair()
767   assert(histo_queue->size > 0);  in HistoQueuePopPair()
768   *pair = histo_queue->queue[histo_queue->size - 1];  in HistoQueuePopPair()
769   --histo_queue->size;  in HistoQueuePopPair()
773 static void HistoQueueUpdateHead(HistoQueue* const histo_queue,  in HistoQueueUpdateHead()  argument
776   assert(pair >= histo_queue->queue &&  in HistoQueueUpdateHead()
777          pair < (histo_queue->queue + histo_queue->size));  in HistoQueueUpdateHead()
778   assert(histo_queue->size > 0);  in HistoQueueUpdateHead()
779   if (pair->cost_diff < histo_queue->queue[0].cost_diff) {  in HistoQueueUpdateHead()
781     const HistogramPair tmp = histo_queue->queue[0];  in HistoQueueUpdateHead()
782     histo_queue->queue[0] = *pair;  in HistoQueueUpdateHead()
802 static double HistoQueuePush(HistoQueue* const histo_queue,  in HistoQueuePush()  argument
810   if (histo_queue->size == histo_queue->max_size) return 0.;  in HistoQueuePush()
827   histo_queue->queue[histo_queue->size++] = pair;  in HistoQueuePush()
828   HistoQueueUpdateHead(histo_queue, &histo_queue->queue[histo_queue->size - 1]);  in HistoQueuePush()
844   HistoQueue histo_queue;  in HistogramCombineGreedy()  local
853   if (!HistoQueueInit(&histo_queue, image_histo_size * image_histo_size)) {  in HistogramCombineGreedy()
862       HistoQueuePush(&histo_queue, histograms, i, j, 0.);  in HistogramCombineGreedy()
866   while (histo_queue.size > 0) {  in HistogramCombineGreedy()
867     const int idx1 = histo_queue.queue[0].idx1;  in HistogramCombineGreedy()
868     const int idx2 = histo_queue.queue[0].idx2;  in HistogramCombineGreedy()
870     histograms[idx1]->bit_cost_ = histo_queue.queue[0].cost_combo;  in HistogramCombineGreedy()
876     for (i = 0; i < histo_queue.size;) {  in HistogramCombineGreedy()
877       HistogramPair* const p = histo_queue.queue + i;  in HistogramCombineGreedy()
880         HistoQueuePopPair(&histo_queue, p);  in HistogramCombineGreedy()
882         HistoQueueUpdateHead(&histo_queue, p);  in HistogramCombineGreedy()
890       HistoQueuePush(&histo_queue, image_histo->histograms, idx1, i, 0.);  in HistogramCombineGreedy()
897   HistoQueueClear(&histo_queue);  in HistogramCombineGreedy()
920   HistoQueue histo_queue;  in HistogramCombineStochastic()  local
934   if (!HistoQueueInit(&histo_queue, kHistoQueueSize)) goto End;  in HistogramCombineStochastic()
949         (histo_queue.size == 0) ? 0. : histo_queue.queue[0].cost_diff;  in HistogramCombineStochastic()
969           HistoQueuePush(&histo_queue, histograms, idx1, idx2, best_cost);  in HistogramCombineStochastic()
973         if (histo_queue.size == histo_queue.max_size) break;  in HistogramCombineStochastic()
976     if (histo_queue.size == 0) continue;  in HistogramCombineStochastic()
979     best_idx1 = histo_queue.queue[0].idx1;  in HistogramCombineStochastic()
980     best_idx2 = histo_queue.queue[0].idx2;  in HistogramCombineStochastic()
991     histograms[best_idx1]->bit_cost_ = histo_queue.queue[0].cost_combo;  in HistogramCombineStochastic()
995     for (j = 0; j < histo_queue.size;) {  in HistogramCombineStochastic()
996       HistogramPair* const p = histo_queue.queue + j;  in HistogramCombineStochastic()
1003         HistoQueuePopPair(&histo_queue, p);  in HistogramCombineStochastic()
1025           HistoQueuePopPair(&histo_queue, p);  in HistogramCombineStochastic()
1029       HistoQueueUpdateHead(&histo_queue, p);  in HistogramCombineStochastic()
1038   HistoQueueClear(&histo_queue);  in HistogramCombineStochastic()