NuCachedSource2.h revision 0d35dd2068d6422c3c77fb68f248cbabf3d0b10c 
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    static sp<NuCachedSource2> Create(
32            const sp<DataSource> &source,
33            const char *cacheConfig = NULL,
34            bool disconnectAtHighwatermark = false);
35
36    virtual status_t initCheck() const;
37
38    virtual ssize_t readAt(off64_t offset, void *data, size_t size);
39
40    virtual void disconnect();
41
42    virtual status_t getSize(off64_t *size);
43    virtual uint32_t flags();
44
45    virtual sp<DecryptHandle> DrmInitialization(const char* mime);
46    virtual void getDrmInfo(sp<DecryptHandle> &handle, DrmManagerClient **client);
47    virtual String8 getUri();
48
49    virtual String8 getMIMEType() const;
50
51    ////////////////////////////////////////////////////////////////////////////
52
53    size_t cachedSize();
54    size_t approxDataRemaining(status_t *finalStatus) const;
55
56    void resumeFetchingIfNecessary();
57
58    // The following methods are supported only if the
59    // data source is HTTP-based; otherwise, ERROR_UNSUPPORTED
60    // is returned.
61    status_t getEstimatedBandwidthKbps(int32_t *kbps);
62    status_t setCacheStatCollectFreq(int32_t freqMs);
63
64    static void RemoveCacheSpecificHeaders(
65            KeyedVector<String8, String8> *headers,
66            String8 *cacheConfig,
67            bool *disconnectAtHighwatermark);
68
69protected:
70    virtual ~NuCachedSource2();
71
72private:
73    friend struct AHandlerReflector<NuCachedSource2>;
74
75    NuCachedSource2(
76            const sp<DataSource> &source,
77            const char *cacheConfig,
78            bool disconnectAtHighwatermark);
79
80    enum {
81        kPageSize                       = 65536,
82        kDefaultHighWaterThreshold      = 20 * 1024 * 1024,
83        kDefaultLowWaterThreshold       = 4 * 1024 * 1024,
84
85        // Read data after a 15 sec timeout whether we're actively
86        // fetching or not.
87        kDefaultKeepAliveIntervalUs     = 15000000,
88    };
89
90    enum {
91        kWhatFetchMore  = 'fetc',
92        kWhatRead       = 'read',
93    };
94
95    enum {
96        kMaxNumRetries = 10,
97    };
98
99    sp<DataSource> mSource;
100    sp<AHandlerReflector<NuCachedSource2> > mReflector;
101    sp<ALooper> mLooper;
102
103    Mutex mSerializer;
104    mutable Mutex mLock;
105    Condition mCondition;
106
107    PageCache *mCache;
108    off64_t mCacheOffset;
109    status_t mFinalStatus;
110    off64_t mLastAccessPos;
111    sp<AMessage> mAsyncResult;
112    bool mFetching;
113    bool mDisconnecting;
114    int64_t mLastFetchTimeUs;
115
116    int32_t mNumRetriesLeft;
117
118    size_t mHighwaterThresholdBytes;
119    size_t mLowwaterThresholdBytes;
120
121    // If the keep-alive interval is 0, keep-alives are disabled.
122    int64_t mKeepAliveIntervalUs;
123
124    bool mDisconnectAtHighwatermark;
125
126    void onMessageReceived(const sp<AMessage> &msg);
127    void onFetch();
128    void onRead(const sp<AMessage> &msg);
129
130    void fetchInternal();
131    ssize_t readInternal(off64_t offset, void *data, size_t size);
132    status_t seekInternal_l(off64_t offset);
133
134    size_t approxDataRemaining_l(status_t *finalStatus) const;
135
136    void restartPrefetcherIfNecessary_l(
137            bool ignoreLowWaterThreshold = false, bool force = false);
138
139    void updateCacheParamsFromSystemProperty();
140    void updateCacheParamsFromString(const char *s);
141
142    DISALLOW_EVIL_CONSTRUCTORS(NuCachedSource2);
143};
144
145}  // namespace android
146
147#endif  // NU_CACHED_SOURCE_2_H_
148