SessionMap.h revision fdd65a0fc7df2c878cc601e4c0f4021cb264f051 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef __SESSIONMAP_H__
18#define __SESSIONMAP_H__
19
20#include <utils/KeyedVector.h>
21
22namespace android {
23
24/**
25 * A wrapper template class for handling DRM Engine sessions.
26 */
27template <typename NODE>
28class SessionMap {
29
30public:
31    KeyedVector<int, NODE> map;
32
33    SessionMap() {}
34
35    virtual ~SessionMap() {
36        destroyMap();
37    }
38
39/**
40 * Adds a new value in the session map table. It expects memory to be allocated already
41 * for the session object
42 *
43 * @param key - key or Session ID
44 * @param value - session object to add
45 *
46 * @return boolean result of adding value. returns false if key is already exist.
47 */
48bool addValue(int key, NODE value) {
49    bool result = false;
50
51    if (!isCreated(key)) {
52        map.add(key, value);
53        result = true;
54    }
55
56    return result;
57}
58
59
60/**
61 * returns the session object by the key
62 *
63 * @param key - key or Session ID
64 *
65 * @return session object as per the key
66 */
67NODE getValue(int key) {
68    NODE value = NULL;
69
70    if (isCreated(key)) {
71        value = (NODE) map.valueFor(key);
72    }
73
74    return value;
75}
76
77/**
78 * returns the number of objects in the session map table
79 *
80 * @return count of number of session objects.
81 */
82int getSize() {
83    return map.size();
84}
85
86/**
87 * returns the session object by the index in the session map table
88 *
89 * @param index - index of the value required
90 *
91 * @return session object as per the index
92 */
93NODE getValueAt(unsigned int index) {
94    NODE value = NULL;
95
96    if (map.size() > index) {
97      value = map.valueAt(index);
98    }
99
100    return value;
101}
102
103/**
104 * deletes the object from session map. It also frees up memory for the session object.
105 *
106 * @param key - key of the value to be deleted
107 *
108 */
109void removeValue(int key) {
110    deleteValue(getValue(key));
111    map.removeItem(key);
112}
113
114/**
115 * decides if session is already created.
116 *
117 * @param key - key of the value for the session
118 *
119 * @return boolean result of whether session is created
120 */
121bool isCreated(int key) {
122    return (0 <= map.indexOfKey(key));
123}
124
125/**
126 * empty the entire session table. It releases all the memory for session objects.
127 */
128void destroyMap() {
129    int size = map.size();
130    int i = 0;
131
132    for (i = 0; i < size; i++) {
133        deleteValue(map.valueAt(i));
134    }
135
136    map.clear();
137}
138
139/**
140 * free up the memory for the session object.
141 * Make sure if any reference to the session object anywhere, otherwise it will be a
142 * dangle pointer after this call.
143 *
144 * @param value - session object to free
145 *
146 */
147void deleteValue(NODE value) {
148    delete value;
149}
150
151};
152
153};
154
155#endif /* __SESSIONMAP_H__ */
156