DataSource.h revision 6511c9755c3a3360ba869772600c7aae048a7ffc 
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 DATA_SOURCE_H_
18
19#define DATA_SOURCE_H_
20
21#include <sys/types.h>
22
23#include <utils/Errors.h>
24#include <utils/KeyedVector.h>
25#include <utils/List.h>
26#include <utils/RefBase.h>
27#include <utils/threads.h>
28#include <drm/DrmManagerClient.h>
29
30namespace android {
31
32struct AMessage;
33class String8;
34
35class DataSource : public RefBase {
36public:
37    enum Flags {
38        kWantsPrefetching      = 1,
39        kStreamedFromLocalHost = 2,
40        kIsCachingDataSource   = 4,
41    };
42
43    static sp<DataSource> CreateFromURI(
44            const char *uri,
45            const KeyedVector<String8, String8> *headers = NULL);
46
47    DataSource() {}
48
49    virtual status_t initCheck() const = 0;
50
51    virtual ssize_t readAt(off64_t offset, void *data, size_t size) = 0;
52
53    // Convenience methods:
54    bool getUInt16(off64_t offset, uint16_t *x);
55
56    // May return ERROR_UNSUPPORTED.
57    virtual status_t getSize(off64_t *size);
58
59    virtual uint32_t flags() {
60        return 0;
61    }
62
63    ////////////////////////////////////////////////////////////////////////////
64
65    bool sniff(String8 *mimeType, float *confidence, sp<AMessage> *meta);
66
67    // The sniffer can optionally fill in "meta" with an AMessage containing
68    // a dictionary of values that helps the corresponding extractor initialize
69    // its state without duplicating effort already exerted by the sniffer.
70    typedef bool (*SnifferFunc)(
71            const sp<DataSource> &source, String8 *mimeType,
72            float *confidence, sp<AMessage> *meta);
73
74    static void RegisterSniffer(SnifferFunc func);
75    static void RegisterDefaultSniffers();
76
77    // for DRM
78    virtual sp<DecryptHandle> DrmInitialization() {
79        return NULL;
80    }
81    virtual void getDrmInfo(sp<DecryptHandle> &handle, DrmManagerClient **client) {};
82
83    virtual String8 getUri() {
84        return String8();
85    }
86
87    virtual String8 getMIMEType() const;
88
89protected:
90    virtual ~DataSource() {}
91
92private:
93    static Mutex gSnifferMutex;
94    static List<SnifferFunc> gSniffers;
95
96    DataSource(const DataSource &);
97    DataSource &operator=(const DataSource &);
98};
99
100}  // namespace android
101
102#endif  // DATA_SOURCE_H_
103