1/*
2 * Copyright 2015 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 ANDROID_CALLBACKDATASOURCE_H
18#define ANDROID_CALLBACKDATASOURCE_H
19
20#include <media/stagefright/DataSource.h>
21#include <media/stagefright/foundation/ADebug.h>
22
23namespace android {
24
25class IDataSource;
26class IMemory;
27
28// A stagefright DataSource that wraps a binder IDataSource. It's a "Callback"
29// DataSource because it calls back to the IDataSource for data.
30class CallbackDataSource : public DataSource {
31public:
32    CallbackDataSource(const sp<IDataSource>& iDataSource);
33    virtual ~CallbackDataSource();
34
35    // DataSource implementation.
36    virtual status_t initCheck() const;
37    virtual ssize_t readAt(off64_t offset, void *data, size_t size);
38    virtual status_t getSize(off64_t *size);
39    virtual uint32_t flags();
40    virtual void close();
41    virtual String8 toString() {
42        return mName;
43    }
44    virtual sp<DecryptHandle> DrmInitialization(const char *mime = NULL);
45
46private:
47    sp<IDataSource> mIDataSource;
48    sp<IMemory> mMemory;
49    bool mIsClosed;
50    String8 mName;
51
52    DISALLOW_EVIL_CONSTRUCTORS(CallbackDataSource);
53};
54
55
56// A caching DataSource that wraps a CallbackDataSource. For reads smaller
57// than kCacheSize it will read up to kCacheSize ahead and cache it.
58// This reduces the number of binder round trips to the IDataSource and has a significant
59// impact on time taken for filetype sniffing and metadata extraction.
60class TinyCacheSource : public DataSource {
61public:
62    TinyCacheSource(const sp<DataSource>& source);
63
64    virtual status_t initCheck() const;
65    virtual ssize_t readAt(off64_t offset, void* data, size_t size);
66    virtual status_t getSize(off64_t* size);
67    virtual uint32_t flags();
68    virtual void close() { mSource->close(); }
69    virtual String8 toString() {
70        return mName;
71    }
72    virtual sp<DecryptHandle> DrmInitialization(const char *mime = NULL);
73
74private:
75    // 2kb comes from experimenting with the time-to-first-frame from a MediaPlayer
76    // with an in-memory MediaDataSource source on a Nexus 5. Beyond 2kb there was
77    // no improvement.
78    enum {
79        kCacheSize = 2048,
80    };
81
82    sp<DataSource> mSource;
83    uint8_t mCache[kCacheSize];
84    off64_t mCachedOffset;
85    size_t mCachedSize;
86    String8 mName;
87
88    DISALLOW_EVIL_CONSTRUCTORS(TinyCacheSource);
89};
90
91}; // namespace android
92
93#endif // ANDROID_CALLBACKDATASOURCE_H
94