YTSFlix_Go/vendor/github.com/RoaringBitmap/roaring/priorityqueue.go
2018-11-04 15:58:15 +01:00

102 lines
2.1 KiB
Go

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)
//}