NuCachedSource2.h revision 889b340ec736a9d3e3e690256d305cc8740f0c4b 
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 NU_CACHED_SOURCE_2_H_
18
19#define NU_CACHED_SOURCE_2_H_
20
21#include <media/stagefright/foundation/ABase.h>
22#include <media/stagefright/foundation/AHandlerReflector.h>
23#include <media/stagefright/DataSource.h>
24
25namespace android {
26
27struct ALooper;
28struct PageCache;
29
30struct NuCachedSource2 : public DataSource {
31    NuCachedSource2(const sp<DataSource> &source);
32
33    virtual status_t initCheck() const;
34
35    virtual ssize_t readAt(off64_t offset, void *data, size_t size);
36
37    virtual status_t getSize(off64_t *size);
38    virtual uint32_t flags();
39
40    virtual DecryptHandle* DrmInitialization();
41    virtual void getDrmInfo(DecryptHandle **handle, DrmManagerClient **client);
42    virtual String8 getUri();
43    ////////////////////////////////////////////////////////////////////////////
44
45    size_t cachedSize();
46    size_t approxDataRemaining(status_t *finalStatus);
47
48    void resumeFetchingIfNecessary();
49
50protected:
51    virtual ~NuCachedSource2();
52
53private:
54    friend struct AHandlerReflector<NuCachedSource2>;
55
56    enum {
57        kPageSize            = 65536,
58        kHighWaterThreshold  = 20 * 1024 * 1024,
59        kLowWaterThreshold   = 4 * 1024 * 1024,
60
61        // Read data after a 15 sec timeout whether we're actively
62        // fetching or not.
63        kKeepAliveIntervalUs = 15000000,
64    };
65
66    enum {
67        kWhatFetchMore  = 'fetc',
68        kWhatRead       = 'read',
69    };
70
71    sp<DataSource> mSource;
72    sp<AHandlerReflector<NuCachedSource2> > mReflector;
73    sp<ALooper> mLooper;
74
75    Mutex mSerializer;
76    Mutex mLock;
77    Condition mCondition;
78
79    PageCache *mCache;
80    off64_t mCacheOffset;
81    status_t mFinalStatus;
82    off64_t mLastAccessPos;
83    sp<AMessage> mAsyncResult;
84    bool mFetching;
85    int64_t mLastFetchTimeUs;
86
87    void onMessageReceived(const sp<AMessage> &msg);
88    void onFetch();
89    void onRead(const sp<AMessage> &msg);
90
91    void fetchInternal();
92    ssize_t readInternal(off64_t offset, void *data, size_t size);
93    status_t seekInternal_l(off64_t offset);
94
95    size_t approxDataRemaining_l(status_t *finalStatus);
96    void restartPrefetcherIfNecessary_l(bool ignoreLowWaterThreshold = false);
97
98    DISALLOW_EVIL_CONSTRUCTORS(NuCachedSource2);
99};
100
101}  // namespace android
102
103#endif  // NU_CACHED_SOURCE_2_H_
104