1 files changed, 57 insertions, 0 deletions
diff --git a/common/prque/prque.go b/common/prque/prque.go
new file mode 100755
index 000000000..9fd31a2e5
--- /dev/null
+++ b/common/prque/prque.go
@@ -0,0 +1,57 @@
+// This is a duplicated and slightly modified version of "gopkg.in/karalabe/cookiejar.v2/collections/prque".
+
+package prque
+
+import (
+	"container/heap"
+)
+
+// Priority queue data structure.
+type Prque struct {
+	cont *sstack
+}
+
+// Creates a new priority queue.
+func New(setIndex setIndexCallback) *Prque {
+	return &Prque{newSstack(setIndex)}
+}
+
+// Pushes a value with a given priority into the queue, expanding if necessary.
+func (p *Prque) Push(data interface{}, priority int64) {
+	heap.Push(p.cont, &item{data, priority})
+}
+
+// Pops the value with the greates priority off the stack and returns it.
+// Currently no shrinking is done.
+func (p *Prque) Pop() (interface{}, int64) {
+	item := heap.Pop(p.cont).(*item)
+	return item.value, item.priority
+}
+
+// Pops only the item from the queue, dropping the associated priority value.
+func (p *Prque) PopItem() interface{} {
+	return heap.Pop(p.cont).(*item).value
+}
+
+// Remove removes the element with the given index.
+func (p *Prque) Remove(i int) interface{} {
+	if i < 0 {
+		return nil
+	}
+	return heap.Remove(p.cont, i)
+}
+
+// Checks whether the priority queue is empty.
+func (p *Prque) Empty() bool {
+	return p.cont.Len() == 0
+}
+
+// Returns the number of element in the priority queue.
+func (p *Prque) Size() int {
+	return p.cont.Len()
+}
+
+// Clears the contents of the priority queue.
+func (p *Prque) Reset() {
+	*p = *New(p.cont.setIndex)
+}