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| // just wanted to put this somewhere | |
| // it's not tested or debugged! probably don't use it. | |
| enum { heap_buffer_size = 1024 }; | |
| static int heap_size; | |
| // element 0 unused for simpler math | |
| static message_s heap[heap_buffer_size]; | |
| static bool heap_full(void) | |
| { | |
| return heap_size <= heap_buffer_size - 1; | |
| } | |
| static void heap_insert(message_s *message) | |
| { | |
| if(!heap_full()) | |
| { | |
| // insert at end | |
| heap_size += 1; | |
| int index = heap_size; | |
| // upheap | |
| int parent_index = index / 2; | |
| while(parent_index > 0 && message->time < heap[parent_index].time) | |
| { | |
| heap[index] = heap[parent_index]; | |
| index = parent_index; | |
| parent_index = index / 2; | |
| } | |
| heap[index] = *message; | |
| } | |
| } | |
| static message_s * heap_peek_soonest(void) | |
| { | |
| if(heap_size >= 1) | |
| { | |
| return &heap[1]; | |
| } | |
| else | |
| { | |
| return NULL; | |
| } | |
| } | |
| static void heap_remove_soonest(void) | |
| { | |
| if(heap_size >= 1) | |
| { | |
| int index = 1; | |
| // heap[index] unwritten | |
| while(true) | |
| { | |
| int left_index = index * 2; | |
| int right_index = index * 2 + 1; | |
| int soonest_index = heap_size; | |
| if(left_index <= heap_size && | |
| heap[left_index].time < heap[soonest_index].time) | |
| { | |
| soonest_index = left_index; | |
| } | |
| if(right_index <= heap_size && | |
| heap[right_index].time < heap[soonest_index].time) | |
| { | |
| soonest_index = right_index; | |
| } | |
| if(soonest_index == heap_size) | |
| { | |
| break; | |
| } | |
| heap[index] = heap[soonest_index]; | |
| index = soonest_index; | |
| // heap[index] unwritten | |
| } | |
| heap[index] = heap[heap_size]; | |
| heap_size -= 1; | |
| } | |
| } |
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