diff --git a/pkg/scheduler/internal/queue/scheduling_queue.go b/pkg/scheduler/internal/queue/scheduling_queue.go index 9bf40361b4..0b4728851b 100644 --- a/pkg/scheduler/internal/queue/scheduling_queue.go +++ b/pkg/scheduler/internal/queue/scheduling_queue.go @@ -27,7 +27,6 @@ limitations under the License. package queue import ( - "container/heap" "fmt" "reflect" "sync" @@ -184,7 +183,7 @@ type PriorityQueue struct { // activeQ is heap structure that scheduler actively looks at to find pods to // schedule. Head of heap is the highest priority pod. - activeQ *Heap + activeQ *util.Heap // unschedulableQ holds pods that have been tried and determined unschedulable. unschedulableQ *UnschedulablePodsMap // nominatedPods is a map keyed by a node name and the value is a list of @@ -230,7 +229,7 @@ func activeQComp(pod1, pod2 interface{}) bool { // NewPriorityQueue creates a PriorityQueue object. func NewPriorityQueue() *PriorityQueue { pq := &PriorityQueue{ - activeQ: newHeap(cache.MetaNamespaceKeyFunc, activeQComp), + activeQ: util.NewHeap(cache.MetaNamespaceKeyFunc, activeQComp), unschedulableQ: newUnschedulablePodsMap(), nominatedPods: map[string][]*v1.Pod{}, } @@ -355,7 +354,7 @@ func (p *PriorityQueue) AddUnschedulableIfNotPresent(pod *v1.Pod) error { func (p *PriorityQueue) Pop() (*v1.Pod, error) { p.lock.Lock() defer p.lock.Unlock() - for len(p.activeQ.data.queue) == 0 { + for p.activeQ.Len() == 0 { // When the queue is empty, invocation of Pop() is blocked until new item is enqueued. // When Close() is called, the p.closed is set and the condition is broadcast, // which causes this loop to continue and return from the Pop(). @@ -591,200 +590,3 @@ func newUnschedulablePodsMap() *UnschedulablePodsMap { keyFunc: util.GetPodFullName, } } - -// Below is the implementation of the a heap. The logic is pretty much the same -// as cache.heap, however, this heap does not perform synchronization. It leaves -// synchronization to the SchedulingQueue. - -// LessFunc is a function type to compare two objects. -type LessFunc func(interface{}, interface{}) bool - -// KeyFunc is a function type to get the key from an object. -type KeyFunc func(obj interface{}) (string, error) - -type heapItem struct { - obj interface{} // The object which is stored in the heap. - index int // The index of the object's key in the Heap.queue. -} - -type itemKeyValue struct { - key string - obj interface{} -} - -// heapData is an internal struct that implements the standard heap interface -// and keeps the data stored in the heap. -type heapData struct { - // items is a map from key of the objects to the objects and their index. - // We depend on the property that items in the map are in the queue and vice versa. - items map[string]*heapItem - // queue implements a heap data structure and keeps the order of elements - // according to the heap invariant. The queue keeps the keys of objects stored - // in "items". - queue []string - - // keyFunc is used to make the key used for queued item insertion and retrieval, and - // should be deterministic. - keyFunc KeyFunc - // lessFunc is used to compare two objects in the heap. - lessFunc LessFunc -} - -var ( - _ = heap.Interface(&heapData{}) // heapData is a standard heap -) - -// Less compares two objects and returns true if the first one should go -// in front of the second one in the heap. -func (h *heapData) Less(i, j int) bool { - if i > len(h.queue) || j > len(h.queue) { - return false - } - itemi, ok := h.items[h.queue[i]] - if !ok { - return false - } - itemj, ok := h.items[h.queue[j]] - if !ok { - return false - } - return h.lessFunc(itemi.obj, itemj.obj) -} - -// Len returns the number of items in the Heap. -func (h *heapData) Len() int { return len(h.queue) } - -// Swap implements swapping of two elements in the heap. This is a part of standard -// heap interface and should never be called directly. -func (h *heapData) Swap(i, j int) { - h.queue[i], h.queue[j] = h.queue[j], h.queue[i] - item := h.items[h.queue[i]] - item.index = i - item = h.items[h.queue[j]] - item.index = j -} - -// Push is supposed to be called by heap.Push only. -func (h *heapData) Push(kv interface{}) { - keyValue := kv.(*itemKeyValue) - n := len(h.queue) - h.items[keyValue.key] = &heapItem{keyValue.obj, n} - h.queue = append(h.queue, keyValue.key) -} - -// Pop is supposed to be called by heap.Pop only. -func (h *heapData) Pop() interface{} { - key := h.queue[len(h.queue)-1] - h.queue = h.queue[0 : len(h.queue)-1] - item, ok := h.items[key] - if !ok { - // This is an error - return nil - } - delete(h.items, key) - return item.obj -} - -// Heap is a producer/consumer queue that implements a heap data structure. -// It can be used to implement priority queues and similar data structures. -type Heap struct { - // data stores objects and has a queue that keeps their ordering according - // to the heap invariant. - data *heapData -} - -// Add inserts an item, and puts it in the queue. The item is updated if it -// already exists. -func (h *Heap) Add(obj interface{}) error { - key, err := h.data.keyFunc(obj) - if err != nil { - return cache.KeyError{Obj: obj, Err: err} - } - if _, exists := h.data.items[key]; exists { - h.data.items[key].obj = obj - heap.Fix(h.data, h.data.items[key].index) - } else { - heap.Push(h.data, &itemKeyValue{key, obj}) - } - return nil -} - -// AddIfNotPresent inserts an item, and puts it in the queue. If an item with -// the key is present in the map, no changes is made to the item. -func (h *Heap) AddIfNotPresent(obj interface{}) error { - key, err := h.data.keyFunc(obj) - if err != nil { - return cache.KeyError{Obj: obj, Err: err} - } - if _, exists := h.data.items[key]; !exists { - heap.Push(h.data, &itemKeyValue{key, obj}) - } - return nil -} - -// Update is the same as Add in this implementation. When the item does not -// exist, it is added. -func (h *Heap) Update(obj interface{}) error { - return h.Add(obj) -} - -// Delete removes an item. -func (h *Heap) Delete(obj interface{}) error { - key, err := h.data.keyFunc(obj) - if err != nil { - return cache.KeyError{Obj: obj, Err: err} - } - if item, ok := h.data.items[key]; ok { - heap.Remove(h.data, item.index) - return nil - } - return fmt.Errorf("object not found") -} - -// Pop returns the head of the heap. -func (h *Heap) Pop() (interface{}, error) { - obj := heap.Pop(h.data) - if obj != nil { - return obj, nil - } - return nil, fmt.Errorf("object was removed from heap data") -} - -// Get returns the requested item, or sets exists=false. -func (h *Heap) Get(obj interface{}) (interface{}, bool, error) { - key, err := h.data.keyFunc(obj) - if err != nil { - return nil, false, cache.KeyError{Obj: obj, Err: err} - } - return h.GetByKey(key) -} - -// GetByKey returns the requested item, or sets exists=false. -func (h *Heap) GetByKey(key string) (interface{}, bool, error) { - item, exists := h.data.items[key] - if !exists { - return nil, false, nil - } - return item.obj, true, nil -} - -// List returns a list of all the items. -func (h *Heap) List() []interface{} { - list := make([]interface{}, 0, len(h.data.items)) - for _, item := range h.data.items { - list = append(list, item.obj) - } - return list -} - -// newHeap returns a Heap which can be used to queue up items to process. -func newHeap(keyFn KeyFunc, lessFn LessFunc) *Heap { - return &Heap{ - data: &heapData{ - items: map[string]*heapItem{}, - queue: []string{}, - keyFunc: keyFn, - lessFunc: lessFn, - }, - } -} diff --git a/pkg/scheduler/internal/queue/scheduling_queue_test.go b/pkg/scheduler/internal/queue/scheduling_queue_test.go index 73ef4a0081..e7566e3299 100644 --- a/pkg/scheduler/internal/queue/scheduling_queue_test.go +++ b/pkg/scheduler/internal/queue/scheduling_queue_test.go @@ -199,7 +199,7 @@ func TestPriorityQueue_Update(t *testing.T) { } // Update highPriorityPod and add a nominatedNodeName to it. q.Update(&highPriorityPod, &highPriNominatedPod) - if q.activeQ.data.Len() != 1 { + if q.activeQ.Len() != 1 { t.Error("Expected only one item in activeQ.") } if len(q.nominatedPods) != 1 { @@ -250,7 +250,7 @@ func TestPriorityQueue_MoveAllToActiveQueue(t *testing.T) { q.unschedulableQ.addOrUpdate(&unschedulablePod) q.unschedulableQ.addOrUpdate(&highPriorityPod) q.MoveAllToActiveQueue() - if q.activeQ.data.Len() != 3 { + if q.activeQ.Len() != 3 { t.Error("Expected all items to be in activeQ.") } } diff --git a/pkg/scheduler/util/BUILD b/pkg/scheduler/util/BUILD index 810d2c5cb0..19374a7845 100644 --- a/pkg/scheduler/util/BUILD +++ b/pkg/scheduler/util/BUILD @@ -10,6 +10,8 @@ go_test( name = "go_default_test", srcs = [ "backoff_utils_test.go", + "heap_test.go", + "testutil_test.go", "utils_test.go", ], embed = [":go_default_library"], @@ -25,6 +27,8 @@ go_library( name = "go_default_library", srcs = [ "backoff_utils.go", + "heap.go", + "testutil.go", "utils.go", ], importpath = "k8s.io/kubernetes/pkg/scheduler/util", diff --git a/pkg/scheduler/util/heap.go b/pkg/scheduler/util/heap.go new file mode 100644 index 0000000000..d7c5534868 --- /dev/null +++ b/pkg/scheduler/util/heap.go @@ -0,0 +1,223 @@ +/* +Copyright 2018 The Kubernetes Authors. + +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. +*/ + +// Below is the implementation of the a heap. The logic is pretty much the same +// as cache.heap, however, this heap does not perform synchronization. It leaves +// synchronization to the SchedulingQueue. + +package util + +import ( + "container/heap" + "fmt" + + "k8s.io/client-go/tools/cache" +) + +// KeyFunc is a function type to get the key from an object. +type KeyFunc func(obj interface{}) (string, error) + +type heapItem struct { + obj interface{} // The object which is stored in the heap. + index int // The index of the object's key in the Heap.queue. +} + +type itemKeyValue struct { + key string + obj interface{} +} + +// heapData is an internal struct that implements the standard heap interface +// and keeps the data stored in the heap. +type heapData struct { + // items is a map from key of the objects to the objects and their index. + // We depend on the property that items in the map are in the queue and vice versa. + items map[string]*heapItem + // queue implements a heap data structure and keeps the order of elements + // according to the heap invariant. The queue keeps the keys of objects stored + // in "items". + queue []string + + // keyFunc is used to make the key used for queued item insertion and retrieval, and + // should be deterministic. + keyFunc KeyFunc + // lessFunc is used to compare two objects in the heap. + lessFunc LessFunc +} + +var ( + _ = heap.Interface(&heapData{}) // heapData is a standard heap +) + +// Less compares two objects and returns true if the first one should go +// in front of the second one in the heap. +func (h *heapData) Less(i, j int) bool { + if i > len(h.queue) || j > len(h.queue) { + return false + } + itemi, ok := h.items[h.queue[i]] + if !ok { + return false + } + itemj, ok := h.items[h.queue[j]] + if !ok { + return false + } + return h.lessFunc(itemi.obj, itemj.obj) +} + +// Len returns the number of items in the Heap. +func (h *heapData) Len() int { return len(h.queue) } + +// Swap implements swapping of two elements in the heap. This is a part of standard +// heap interface and should never be called directly. +func (h *heapData) Swap(i, j int) { + h.queue[i], h.queue[j] = h.queue[j], h.queue[i] + item := h.items[h.queue[i]] + item.index = i + item = h.items[h.queue[j]] + item.index = j +} + +// Push is supposed to be called by heap.Push only. +func (h *heapData) Push(kv interface{}) { + keyValue := kv.(*itemKeyValue) + n := len(h.queue) + h.items[keyValue.key] = &heapItem{keyValue.obj, n} + h.queue = append(h.queue, keyValue.key) +} + +// Pop is supposed to be called by heap.Pop only. +func (h *heapData) Pop() interface{} { + key := h.queue[len(h.queue)-1] + h.queue = h.queue[0 : len(h.queue)-1] + item, ok := h.items[key] + if !ok { + // This is an error + return nil + } + delete(h.items, key) + return item.obj +} + +// Heap is a producer/consumer queue that implements a heap data structure. +// It can be used to implement priority queues and similar data structures. +type Heap struct { + // data stores objects and has a queue that keeps their ordering according + // to the heap invariant. + data *heapData +} + +// Add inserts an item, and puts it in the queue. The item is updated if it +// already exists. +func (h *Heap) Add(obj interface{}) error { + key, err := h.data.keyFunc(obj) + if err != nil { + return cache.KeyError{Obj: obj, Err: err} + } + if _, exists := h.data.items[key]; exists { + h.data.items[key].obj = obj + heap.Fix(h.data, h.data.items[key].index) + } else { + heap.Push(h.data, &itemKeyValue{key, obj}) + } + return nil +} + +// AddIfNotPresent inserts an item, and puts it in the queue. If an item with +// the key is present in the map, no changes is made to the item. +func (h *Heap) AddIfNotPresent(obj interface{}) error { + key, err := h.data.keyFunc(obj) + if err != nil { + return cache.KeyError{Obj: obj, Err: err} + } + if _, exists := h.data.items[key]; !exists { + heap.Push(h.data, &itemKeyValue{key, obj}) + } + return nil +} + +// Update is the same as Add in this implementation. When the item does not +// exist, it is added. +func (h *Heap) Update(obj interface{}) error { + return h.Add(obj) +} + +// Delete removes an item. +func (h *Heap) Delete(obj interface{}) error { + key, err := h.data.keyFunc(obj) + if err != nil { + return cache.KeyError{Obj: obj, Err: err} + } + if item, ok := h.data.items[key]; ok { + heap.Remove(h.data, item.index) + return nil + } + return fmt.Errorf("object not found") +} + +// Pop returns the head of the heap. +func (h *Heap) Pop() (interface{}, error) { + obj := heap.Pop(h.data) + if obj != nil { + return obj, nil + } + return nil, fmt.Errorf("object was removed from heap data") +} + +// Get returns the requested item, or sets exists=false. +func (h *Heap) Get(obj interface{}) (interface{}, bool, error) { + key, err := h.data.keyFunc(obj) + if err != nil { + return nil, false, cache.KeyError{Obj: obj, Err: err} + } + return h.GetByKey(key) +} + +// GetByKey returns the requested item, or sets exists=false. +func (h *Heap) GetByKey(key string) (interface{}, bool, error) { + item, exists := h.data.items[key] + if !exists { + return nil, false, nil + } + return item.obj, true, nil +} + +// List returns a list of all the items. +func (h *Heap) List() []interface{} { + list := make([]interface{}, 0, len(h.data.items)) + for _, item := range h.data.items { + list = append(list, item.obj) + } + return list +} + +// Len returns the number of items in the heap. +func (h *Heap) Len() int { + return len(h.data.queue) +} + +// NewHeap returns a Heap which can be used to queue up items to process. +func NewHeap(keyFn KeyFunc, lessFn LessFunc) *Heap { + return &Heap{ + data: &heapData{ + items: map[string]*heapItem{}, + queue: []string{}, + keyFunc: keyFn, + lessFunc: lessFn, + }, + } +} diff --git a/pkg/scheduler/util/heap_test.go b/pkg/scheduler/util/heap_test.go new file mode 100644 index 0000000000..62812ec4c9 --- /dev/null +++ b/pkg/scheduler/util/heap_test.go @@ -0,0 +1,271 @@ +/* +Copyright 2018 The Kubernetes Authors. + +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. +*/ + +// This file was copied from client-go/tools/cache/heap.go and modified +// for our non thread-safe heap + +package util + +import ( + "testing" +) + +func testHeapObjectKeyFunc(obj interface{}) (string, error) { + return obj.(testHeapObject).name, nil +} + +type testHeapObject struct { + name string + val interface{} +} + +func mkHeapObj(name string, val interface{}) testHeapObject { + return testHeapObject{name: name, val: val} +} + +func compareInts(val1 interface{}, val2 interface{}) bool { + first := val1.(testHeapObject).val.(int) + second := val2.(testHeapObject).val.(int) + return first < second +} + +// TestHeapBasic tests Heap invariant +func TestHeapBasic(t *testing.T) { + h := NewHeap(testHeapObjectKeyFunc, compareInts) + const amount = 500 + var i int + + for i = amount; i > 0; i-- { + h.Add(mkHeapObj(string([]rune{'a', rune(i)}), i)) + } + + // Make sure that the numbers are popped in ascending order. + prevNum := 0 + for i := 0; i < amount; i++ { + obj, err := h.Pop() + num := obj.(testHeapObject).val.(int) + // All the items must be sorted. + if err != nil || prevNum > num { + t.Errorf("got %v out of order, last was %v", obj, prevNum) + } + prevNum = num + } +} + +// Tests Heap.Add and ensures that heap invariant is preserved after adding items. +func TestHeap_Add(t *testing.T) { + h := NewHeap(testHeapObjectKeyFunc, compareInts) + h.Add(mkHeapObj("foo", 10)) + h.Add(mkHeapObj("bar", 1)) + h.Add(mkHeapObj("baz", 11)) + h.Add(mkHeapObj("zab", 30)) + h.Add(mkHeapObj("foo", 13)) // This updates "foo". + + item, err := h.Pop() + if e, a := 1, item.(testHeapObject).val; err != nil || a != e { + t.Fatalf("expected %d, got %d", e, a) + } + item, err = h.Pop() + if e, a := 11, item.(testHeapObject).val; err != nil || a != e { + t.Fatalf("expected %d, got %d", e, a) + } + h.Delete(mkHeapObj("baz", 11)) // Nothing is deleted. + h.Add(mkHeapObj("foo", 14)) // foo is updated. + item, err = h.Pop() + if e, a := 14, item.(testHeapObject).val; err != nil || a != e { + t.Fatalf("expected %d, got %d", e, a) + } + item, err = h.Pop() + if e, a := 30, item.(testHeapObject).val; err != nil || a != e { + t.Fatalf("expected %d, got %d", e, a) + } +} + +// TestHeap_AddIfNotPresent tests Heap.AddIfNotPresent and ensures that heap +// invariant is preserved after adding items. +func TestHeap_AddIfNotPresent(t *testing.T) { + h := NewHeap(testHeapObjectKeyFunc, compareInts) + h.AddIfNotPresent(mkHeapObj("foo", 10)) + h.AddIfNotPresent(mkHeapObj("bar", 1)) + h.AddIfNotPresent(mkHeapObj("baz", 11)) + h.AddIfNotPresent(mkHeapObj("zab", 30)) + h.AddIfNotPresent(mkHeapObj("foo", 13)) // This is not added. + + if len := len(h.data.items); len != 4 { + t.Errorf("unexpected number of items: %d", len) + } + if val := h.data.items["foo"].obj.(testHeapObject).val; val != 10 { + t.Errorf("unexpected value: %d", val) + } + item, err := h.Pop() + if e, a := 1, item.(testHeapObject).val; err != nil || a != e { + t.Fatalf("expected %d, got %d", e, a) + } + item, err = h.Pop() + if e, a := 10, item.(testHeapObject).val; err != nil || a != e { + t.Fatalf("expected %d, got %d", e, a) + } + // bar is already popped. Let's add another one. + h.AddIfNotPresent(mkHeapObj("bar", 14)) + item, err = h.Pop() + if e, a := 11, item.(testHeapObject).val; err != nil || a != e { + t.Fatalf("expected %d, got %d", e, a) + } + item, err = h.Pop() + if e, a := 14, item.(testHeapObject).val; err != nil || a != e { + t.Fatalf("expected %d, got %d", e, a) + } +} + +// TestHeap_Delete tests Heap.Delete and ensures that heap invariant is +// preserved after deleting items. +func TestHeap_Delete(t *testing.T) { + h := NewHeap(testHeapObjectKeyFunc, compareInts) + h.Add(mkHeapObj("foo", 10)) + h.Add(mkHeapObj("bar", 1)) + h.Add(mkHeapObj("bal", 31)) + h.Add(mkHeapObj("baz", 11)) + + // Delete head. Delete should work with "key" and doesn't care about the value. + if err := h.Delete(mkHeapObj("bar", 200)); err != nil { + t.Fatalf("Failed to delete head.") + } + item, err := h.Pop() + if e, a := 10, item.(testHeapObject).val; err != nil || a != e { + t.Fatalf("expected %d, got %d", e, a) + } + h.Add(mkHeapObj("zab", 30)) + h.Add(mkHeapObj("faz", 30)) + len := h.data.Len() + // Delete non-existing item. + if err = h.Delete(mkHeapObj("non-existent", 10)); err == nil || len != h.data.Len() { + t.Fatalf("Didn't expect any item removal") + } + // Delete tail. + if err = h.Delete(mkHeapObj("bal", 31)); err != nil { + t.Fatalf("Failed to delete tail.") + } + // Delete one of the items with value 30. + if err = h.Delete(mkHeapObj("zab", 30)); err != nil { + t.Fatalf("Failed to delete item.") + } + item, err = h.Pop() + if e, a := 11, item.(testHeapObject).val; err != nil || a != e { + t.Fatalf("expected %d, got %d", e, a) + } + item, err = h.Pop() + if e, a := 30, item.(testHeapObject).val; err != nil || a != e { + t.Fatalf("expected %d, got %d", e, a) + } + if h.data.Len() != 0 { + t.Fatalf("expected an empty heap.") + } +} + +// TestHeap_Update tests Heap.Update and ensures that heap invariant is +// preserved after adding items. +func TestHeap_Update(t *testing.T) { + h := NewHeap(testHeapObjectKeyFunc, compareInts) + h.Add(mkHeapObj("foo", 10)) + h.Add(mkHeapObj("bar", 1)) + h.Add(mkHeapObj("bal", 31)) + h.Add(mkHeapObj("baz", 11)) + + // Update an item to a value that should push it to the head. + h.Update(mkHeapObj("baz", 0)) + if h.data.queue[0] != "baz" || h.data.items["baz"].index != 0 { + t.Fatalf("expected baz to be at the head") + } + item, err := h.Pop() + if e, a := 0, item.(testHeapObject).val; err != nil || a != e { + t.Fatalf("expected %d, got %d", e, a) + } + // Update bar to push it farther back in the queue. + h.Update(mkHeapObj("bar", 100)) + if h.data.queue[0] != "foo" || h.data.items["foo"].index != 0 { + t.Fatalf("expected foo to be at the head") + } +} + +// TestHeap_Get tests Heap.Get. +func TestHeap_Get(t *testing.T) { + h := NewHeap(testHeapObjectKeyFunc, compareInts) + h.Add(mkHeapObj("foo", 10)) + h.Add(mkHeapObj("bar", 1)) + h.Add(mkHeapObj("bal", 31)) + h.Add(mkHeapObj("baz", 11)) + + // Get works with the key. + obj, exists, err := h.Get(mkHeapObj("baz", 0)) + if err != nil || exists == false || obj.(testHeapObject).val != 11 { + t.Fatalf("unexpected error in getting element") + } + // Get non-existing object. + _, exists, err = h.Get(mkHeapObj("non-existing", 0)) + if err != nil || exists == true { + t.Fatalf("didn't expect to get any object") + } +} + +// TestHeap_GetByKey tests Heap.GetByKey and is very similar to TestHeap_Get. +func TestHeap_GetByKey(t *testing.T) { + h := NewHeap(testHeapObjectKeyFunc, compareInts) + h.Add(mkHeapObj("foo", 10)) + h.Add(mkHeapObj("bar", 1)) + h.Add(mkHeapObj("bal", 31)) + h.Add(mkHeapObj("baz", 11)) + + obj, exists, err := h.GetByKey("baz") + if err != nil || exists == false || obj.(testHeapObject).val != 11 { + t.Fatalf("unexpected error in getting element") + } + // Get non-existing object. + _, exists, err = h.GetByKey("non-existing") + if err != nil || exists == true { + t.Fatalf("didn't expect to get any object") + } +} + +// TestHeap_List tests Heap.List function. +func TestHeap_List(t *testing.T) { + h := NewHeap(testHeapObjectKeyFunc, compareInts) + list := h.List() + if len(list) != 0 { + t.Errorf("expected an empty list") + } + + items := map[string]int{ + "foo": 10, + "bar": 1, + "bal": 30, + "baz": 11, + "faz": 30, + } + for k, v := range items { + h.Add(mkHeapObj(k, v)) + } + list = h.List() + if len(list) != len(items) { + t.Errorf("expected %d items, got %d", len(items), len(list)) + } + for _, obj := range list { + heapObj := obj.(testHeapObject) + v, ok := items[heapObj.name] + if !ok || v != heapObj.val { + t.Errorf("unexpected item in the list: %v", heapObj) + } + } +}