[VOL-1386] This commit add "dep" as the package management tool
for voltha-go.
Change-Id: I52bc4911dd00a441756ec7c30f46d45091f3f90e
diff --git a/vendor/github.com/golang-collections/go-datastructures/queue/priority_queue.go b/vendor/github.com/golang-collections/go-datastructures/queue/priority_queue.go
new file mode 100644
index 0000000..3ccfd57
--- /dev/null
+++ b/vendor/github.com/golang-collections/go-datastructures/queue/priority_queue.go
@@ -0,0 +1,235 @@
+/*
+Copyright 2014 Workiva, LLC
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+/*
+The priority queue is almost a spitting image of the logic
+used for a regular queue. In order to keep the logic fast,
+this code is repeated instead of using casts to cast to interface{}
+back and forth. If Go had inheritance and generics, this problem
+would be easier to solve.
+*/
+package queue
+
+import (
+ "sort"
+ "sync"
+)
+
+// Item is an item that can be added to the priority queue.
+type Item interface {
+ // Compare returns a bool that can be used to determine
+ // ordering in the priority queue. Assuming the queue
+ // is in ascending order, this should return > logic.
+ // Return 1 to indicate this object is greater than the
+ // the other logic, 0 to indicate equality, and -1 to indicate
+ // less than other.
+ Compare(other Item) int
+}
+
+type priorityItems []Item
+
+func (items *priorityItems) get(number int) []Item {
+ returnItems := make([]Item, 0, number)
+ index := 0
+ for i := 0; i < number; i++ {
+ if i >= len(*items) {
+ break
+ }
+
+ returnItems = append(returnItems, (*items)[i])
+ (*items)[i] = nil
+ index++
+ }
+
+ *items = (*items)[index:]
+ return returnItems
+}
+
+func (items *priorityItems) insert(item Item) {
+ if len(*items) == 0 {
+ *items = append(*items, item)
+ return
+ }
+
+ equalFound := false
+ i := sort.Search(len(*items), func(i int) bool {
+ result := (*items)[i].Compare(item)
+ if result == 0 {
+ equalFound = true
+ }
+ return result >= 0
+ })
+
+ if equalFound {
+ return
+ }
+
+ if i == len(*items) {
+ *items = append(*items, item)
+ return
+ }
+
+ *items = append(*items, nil)
+ copy((*items)[i+1:], (*items)[i:])
+ (*items)[i] = item
+}
+
+// PriorityQueue is similar to queue except that it takes
+// items that implement the Item interface and adds them
+// to the queue in priority order.
+type PriorityQueue struct {
+ waiters waiters
+ items priorityItems
+ lock sync.Mutex
+ disposeLock sync.Mutex
+ disposed bool
+}
+
+// Put adds items to the queue.
+func (pq *PriorityQueue) Put(items ...Item) error {
+ if len(items) == 0 {
+ return nil
+ }
+
+ pq.lock.Lock()
+ if pq.disposed {
+ pq.lock.Unlock()
+ return disposedError
+ }
+
+ for _, item := range items {
+ pq.items.insert(item)
+ }
+
+ for {
+ sema := pq.waiters.get()
+ if sema == nil {
+ break
+ }
+
+ sema.response.Add(1)
+ sema.wg.Done()
+ sema.response.Wait()
+ if len(pq.items) == 0 {
+ break
+ }
+ }
+
+ pq.lock.Unlock()
+ return nil
+}
+
+// Get retrieves items from the queue. If the queue is empty,
+// this call blocks until the next item is added to the queue. This
+// will attempt to retrieve number of items.
+func (pq *PriorityQueue) Get(number int) ([]Item, error) {
+ if number < 1 {
+ return nil, nil
+ }
+
+ pq.lock.Lock()
+
+ if pq.disposed {
+ pq.lock.Unlock()
+ return nil, disposedError
+ }
+
+ var items []Item
+
+ if len(pq.items) == 0 {
+ sema := newSema()
+ pq.waiters.put(sema)
+ sema.wg.Add(1)
+ pq.lock.Unlock()
+
+ sema.wg.Wait()
+ pq.disposeLock.Lock()
+ if pq.disposed {
+ pq.disposeLock.Unlock()
+ return nil, disposedError
+ }
+ pq.disposeLock.Unlock()
+
+ items = pq.items.get(number)
+ sema.response.Done()
+ return items, nil
+ }
+
+ items = pq.items.get(number)
+ pq.lock.Unlock()
+ return items, nil
+}
+
+// Peek will look at the next item without removing it from the queue.
+func (pq *PriorityQueue) Peek() Item {
+ pq.lock.Lock()
+ defer pq.lock.Unlock()
+ if len(pq.items) > 0 {
+ return pq.items[0]
+ }
+ return nil
+}
+
+// Empty returns a bool indicating if there are any items left
+// in the queue.
+func (pq *PriorityQueue) Empty() bool {
+ pq.lock.Lock()
+ defer pq.lock.Unlock()
+
+ return len(pq.items) == 0
+}
+
+// Len returns a number indicating how many items are in the queue.
+func (pq *PriorityQueue) Len() int {
+ pq.lock.Lock()
+ defer pq.lock.Unlock()
+
+ return len(pq.items)
+}
+
+// Disposed returns a bool indicating if this queue has been disposed.
+func (pq *PriorityQueue) Disposed() bool {
+ pq.lock.Lock()
+ defer pq.lock.Unlock()
+
+ return pq.disposed
+}
+
+// Dispose will prevent any further reads/writes to this queue
+// and frees available resources.
+func (pq *PriorityQueue) Dispose() {
+ pq.lock.Lock()
+ defer pq.lock.Unlock()
+
+ pq.disposeLock.Lock()
+ defer pq.disposeLock.Unlock()
+
+ pq.disposed = true
+ for _, waiter := range pq.waiters {
+ waiter.response.Add(1)
+ waiter.wg.Done()
+ }
+
+ pq.items = nil
+ pq.waiters = nil
+}
+
+// NewPriorityQueue is the constructor for a priority queue.
+func NewPriorityQueue(hint int) *PriorityQueue {
+ return &PriorityQueue{
+ items: make(priorityItems, 0, hint),
+ }
+}