diff options
Diffstat (limited to 'vendor/github.com/RoaringBitmap/roaring/priorityqueue.go')
-rw-r--r-- | vendor/github.com/RoaringBitmap/roaring/priorityqueue.go | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/vendor/github.com/RoaringBitmap/roaring/priorityqueue.go b/vendor/github.com/RoaringBitmap/roaring/priorityqueue.go new file mode 100644 index 0000000000..9259a68163 --- /dev/null +++ b/vendor/github.com/RoaringBitmap/roaring/priorityqueue.go @@ -0,0 +1,101 @@ +package roaring + +import "container/heap" + +///////////// +// The priorityQueue is used to keep Bitmaps sorted. +//////////// + +type item struct { + value *Bitmap + index int +} + +type priorityQueue []*item + +func (pq priorityQueue) Len() int { return len(pq) } + +func (pq priorityQueue) Less(i, j int) bool { + return pq[i].value.GetSizeInBytes() < pq[j].value.GetSizeInBytes() +} + +func (pq priorityQueue) Swap(i, j int) { + pq[i], pq[j] = pq[j], pq[i] + pq[i].index = i + pq[j].index = j +} + +func (pq *priorityQueue) Push(x interface{}) { + n := len(*pq) + item := x.(*item) + item.index = n + *pq = append(*pq, item) +} + +func (pq *priorityQueue) Pop() interface{} { + old := *pq + n := len(old) + item := old[n-1] + item.index = -1 // for safety + *pq = old[0 : n-1] + return item +} + +func (pq *priorityQueue) update(item *item, value *Bitmap) { + item.value = value + heap.Fix(pq, item.index) +} + +///////////// +// The containerPriorityQueue is used to keep the containers of various Bitmaps sorted. +//////////// + +type containeritem struct { + value *Bitmap + keyindex int + index int +} + +type containerPriorityQueue []*containeritem + +func (pq containerPriorityQueue) Len() int { return len(pq) } + +func (pq containerPriorityQueue) Less(i, j int) bool { + k1 := pq[i].value.highlowcontainer.getKeyAtIndex(pq[i].keyindex) + k2 := pq[j].value.highlowcontainer.getKeyAtIndex(pq[j].keyindex) + if k1 != k2 { + return k1 < k2 + } + c1 := pq[i].value.highlowcontainer.getContainerAtIndex(pq[i].keyindex) + c2 := pq[j].value.highlowcontainer.getContainerAtIndex(pq[j].keyindex) + + return c1.getCardinality() > c2.getCardinality() +} + +func (pq containerPriorityQueue) Swap(i, j int) { + pq[i], pq[j] = pq[j], pq[i] + pq[i].index = i + pq[j].index = j +} + +func (pq *containerPriorityQueue) Push(x interface{}) { + n := len(*pq) + item := x.(*containeritem) + item.index = n + *pq = append(*pq, item) +} + +func (pq *containerPriorityQueue) Pop() interface{} { + old := *pq + n := len(old) + item := old[n-1] + item.index = -1 // for safety + *pq = old[0 : n-1] + return item +} + +//func (pq *containerPriorityQueue) update(item *containeritem, value *Bitmap, keyindex int) { +// item.value = value +// item.keyindex = keyindex +// heap.Fix(pq, item.index) +//} |