1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
|
// Copyright 2006 The Closure Library Authors. All Rights Reserved.
//
// 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.
/**
* @fileoverview Datastructure: Priority Pool.
*
*
* An extending of Pool that handles queueing and prioritization.
*/
goog.provide('goog.structs.PriorityPool');
goog.require('goog.structs.Pool');
goog.require('goog.structs.PriorityQueue');
/**
* A generic pool class. If min is greater than max, an error is thrown.
* @param {number=} opt_minCount Min. number of objects (Default: 0).
* @param {number=} opt_maxCount Max. number of objects (Default: 10).
* @constructor
* @extends {goog.structs.Pool<VALUE>}
* @template VALUE
*/
goog.structs.PriorityPool = function(opt_minCount, opt_maxCount) {
/**
* The key for the most recent timeout created.
* @private {number|undefined}
*/
this.delayTimeout_ = undefined;
/**
* Queue of requests for pool objects.
* @private {goog.structs.PriorityQueue<VALUE>}
*/
this.requestQueue_ = new goog.structs.PriorityQueue();
// Must break convention of putting the super-class's constructor first. This
// is because the super-class constructor calls adjustForMinMax, which this
// class overrides. In this class's implementation, it assumes that there
// is a requestQueue_, and will error if not present.
goog.structs.Pool.call(this, opt_minCount, opt_maxCount);
};
goog.inherits(goog.structs.PriorityPool, goog.structs.Pool);
/**
* Default priority for pool objects requests.
* @type {number}
* @private
*/
goog.structs.PriorityPool.DEFAULT_PRIORITY_ = 100;
/** @override */
goog.structs.PriorityPool.prototype.setDelay = function(delay) {
goog.structs.PriorityPool.base(this, 'setDelay', delay);
// If the pool hasn't been accessed yet, no need to do anything.
if (!goog.isDefAndNotNull(this.lastAccess)) {
return;
}
goog.global.clearTimeout(this.delayTimeout_);
this.delayTimeout_ = goog.global.setTimeout(
goog.bind(this.handleQueueRequests_, this),
this.delay + this.lastAccess - goog.now());
// Handle all requests.
this.handleQueueRequests_();
};
/**
* Get a new object from the the pool, if there is one available, otherwise
* return undefined.
* @param {Function=} opt_callback The function to callback when an object is
* available. This could be immediately. If this is not present, then an
* object is immediately returned if available, or undefined if not.
* @param {number=} opt_priority The priority of the request. A smaller value
* means a higher priority.
* @return {VALUE|undefined} The new object from the pool if there is one
* available and a callback is not given. Otherwise, undefined.
* @override
*/
goog.structs.PriorityPool.prototype.getObject = function(
opt_callback, opt_priority) {
if (!opt_callback) {
var result = goog.structs.PriorityPool.base(this, 'getObject');
if (result && this.delay) {
this.delayTimeout_ = goog.global.setTimeout(
goog.bind(this.handleQueueRequests_, this), this.delay);
}
return result;
}
var priority = goog.isDef(opt_priority) ?
opt_priority :
goog.structs.PriorityPool.DEFAULT_PRIORITY_;
this.requestQueue_.enqueue(priority, opt_callback);
// Handle all requests.
this.handleQueueRequests_();
return undefined;
};
/**
* Handles the request queue. Tries to fires off as many queued requests as
* possible.
* @private
*/
goog.structs.PriorityPool.prototype.handleQueueRequests_ = function() {
var requestQueue = this.requestQueue_;
while (requestQueue.getCount() > 0) {
var obj = this.getObject();
if (!obj) {
return;
} else {
var requestCallback = requestQueue.dequeue();
requestCallback.apply(this, [obj]);
}
}
};
/**
* Adds an object to the collection of objects that are free. If the object can
* not be added, then it is disposed.
*
* NOTE: This method does not remove the object from the in use collection.
*
* @param {VALUE} obj The object to add to the collection of free objects.
* @override
*/
goog.structs.PriorityPool.prototype.addFreeObject = function(obj) {
goog.structs.PriorityPool.superClass_.addFreeObject.call(this, obj);
// Handle all requests.
this.handleQueueRequests_();
};
/**
* Adjusts the objects held in the pool to be within the min/max constraints.
*
* NOTE: It is possible that the number of objects in the pool will still be
* greater than the maximum count of objects allowed. This will be the case
* if no more free objects can be disposed of to get below the minimum count
* (i.e., all objects are in use).
* @override
*/
goog.structs.PriorityPool.prototype.adjustForMinMax = function() {
goog.structs.PriorityPool.superClass_.adjustForMinMax.call(this);
// Handle all requests.
this.handleQueueRequests_();
};
/** @override */
goog.structs.PriorityPool.prototype.disposeInternal = function() {
goog.structs.PriorityPool.superClass_.disposeInternal.call(this);
goog.global.clearTimeout(this.delayTimeout_);
this.requestQueue_.clear();
this.requestQueue_ = null;
};
|
