1 /*
2  * Copyright (C) 2009 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 //
18 // Sortable array of strings.  STL-ish, but STL-free.
19 //
20 
21 #include <stdlib.h>
22 #include <string.h>
23 
24 #include <media/StringArray.h>
25 
26 namespace android {
27 
28 //
29 // An expanding array of strings.  Add, get, sort, delete.
30 //
StringArray()31 StringArray::StringArray()
32     : mMax(0), mCurrent(0), mArray(NULL)
33 {
34 }
35 
~StringArray()36 StringArray:: ~StringArray() {
37     for (int i = 0; i < mCurrent; i++)
38         delete[] mArray[i];
39     delete[] mArray;
40 }
41 
42 //
43 // Add a string.  A copy of the string is made.
44 //
push_back(const char * str)45 bool StringArray::push_back(const char* str) {
46     if (mCurrent >= mMax) {
47         char** tmp;
48 
49         if (mMax == 0)
50             mMax = 16;      // initial storage
51         else
52             mMax *= 2;
53 
54         tmp = new char*[mMax];
55         if (tmp == NULL)
56             return false;
57 
58         memcpy(tmp, mArray, mCurrent * sizeof(char*));
59         delete[] mArray;
60         mArray = tmp;
61     }
62 
63     int len = strlen(str);
64     mArray[mCurrent] = new char[len+1];
65     memcpy(mArray[mCurrent], str, len+1);
66     mCurrent++;
67 
68     return true;
69 }
70 
71 //
72 // Delete an entry.
73 //
erase(int idx)74 void StringArray::erase(int idx) {
75     if (idx < 0 || idx >= mCurrent)
76         return;
77     delete[] mArray[idx];
78     if (idx < mCurrent-1) {
79         memmove(&mArray[idx], &mArray[idx+1],
80                 (mCurrent-1 - idx) * sizeof(char*));
81     }
82     mCurrent--;
83 }
84 
85 //
86 // Sort the array.
87 //
sort(int (* compare)(const void *,const void *))88 void StringArray::sort(int (*compare)(const void*, const void*)) {
89     qsort(mArray, mCurrent, sizeof(char*), compare);
90 }
91 
92 //
93 // Pass this to the sort routine to do an ascending alphabetical sort.
94 //
cmpAscendingAlpha(const void * pstr1,const void * pstr2)95 int StringArray::cmpAscendingAlpha(const void* pstr1, const void* pstr2) {
96     return strcmp(*(const char**)pstr1, *(const char**)pstr2);
97 }
98 
99 //
100 // Set entry N to specified string.
101 // [should use operator[] here]
102 //
setEntry(int idx,const char * str)103 void StringArray::setEntry(int idx, const char* str) {
104     if (idx < 0 || idx >= mCurrent)
105         return;
106     delete[] mArray[idx];
107     int len = strlen(str);
108     mArray[idx] = new char[len+1];
109     memcpy(mArray[idx], str, len+1);
110 }
111 
112 
113 } // namespace android
114