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#ifndef CACHING_DATASOURCE_H_
18
19#define CACHING_DATASOURCE_H_
20
21#include <media/stagefright/DataSource.h>
22#include <media/stagefright/MediaErrors.h>
23#include <utils/threads.h>
24
25namespace android {
26
27class CachingDataSource : public DataSource {
28public:
29    CachingDataSource(
30            const sp<DataSource> &source, size_t pageSize, int numPages);
31
32    virtual status_t initCheck() const;
33
34    virtual ssize_t readAt(off_t offset, void *data, size_t size);
35
36    virtual status_t getSize(off_t *size);
37
38    virtual uint32_t flags();
39
40protected:
41    virtual ~CachingDataSource();
42
43private:
44    struct Page {
45        Page *mPrev, *mNext;
46        off_t mOffset;
47        size_t mLength;
48        void *mData;
49    };
50
51    sp<DataSource> mSource;
52    void *mData;
53    size_t mPageSize;
54    Page *mFirst, *mLast;
55
56    Page *allocate_page();
57
58    Mutex mLock;
59
60    CachingDataSource(const CachingDataSource &);
61    CachingDataSource &operator=(const CachingDataSource &);
62};
63
64}  // namespace android
65
66#endif  // CACHING_DATASOURCE_H_
67