NuCachedSource2.h revision a628f89503e024e2b3f4dad88edd326845e058b9 
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(off_t offset, void *data, size_t size);
36
37    virtual status_t getSize(off_t *size);
38    virtual uint32_t flags();
39
40    virtual DecryptHandle* DrmInitialization(DrmManagerClient *client);
41    virtual void getDrmInfo(DecryptHandle **handle, DrmManagerClient **client);
42    ////////////////////////////////////////////////////////////////////////////
43
44    size_t cachedSize();
45    size_t approxDataRemaining(bool *eos);
46
47    void suspend();
48    void clearCacheAndResume();
49
50    void resumeFetchingIfNecessary();
51
52protected:
53    virtual ~NuCachedSource2();
54
55private:
56    friend struct AHandlerReflector<NuCachedSource2>;
57
58    enum {
59        kPageSize            = 65536,
60        kHighWaterThreshold  = 5 * 1024 * 1024,
61        kLowWaterThreshold   = 1024 * 1024,
62
63        // Read data after a 15 sec timeout whether we're actively
64        // fetching or not.
65        kKeepAliveIntervalUs = 15000000,
66    };
67
68    enum {
69        kWhatFetchMore  = 'fetc',
70        kWhatRead       = 'read',
71        kWhatSuspend    = 'susp',
72    };
73
74    sp<DataSource> mSource;
75    sp<AHandlerReflector<NuCachedSource2> > mReflector;
76    sp<ALooper> mLooper;
77
78    Mutex mSerializer;
79    Mutex mLock;
80    Condition mCondition;
81
82    PageCache *mCache;
83    off_t mCacheOffset;
84    status_t mFinalStatus;
85    off_t mLastAccessPos;
86    sp<AMessage> mAsyncResult;
87    bool mFetching;
88    int64_t mLastFetchTimeUs;
89    bool mSuspended;
90
91    void onMessageReceived(const sp<AMessage> &msg);
92    void onFetch();
93    void onRead(const sp<AMessage> &msg);
94    void onSuspend();
95
96    void fetchInternal();
97    ssize_t readInternal(off_t offset, void *data, size_t size);
98    status_t seekInternal_l(off_t offset);
99
100    size_t approxDataRemaining_l(bool *eos);
101    void restartPrefetcherIfNecessary_l(bool ignoreLowWaterThreshold = false);
102
103    DISALLOW_EVIL_CONSTRUCTORS(NuCachedSource2);
104};
105
106}  // namespace android
107
108#endif  // NU_CACHED_SOURCE_2_H_
109