DataSource.h revision acdd9d0f59c3d8bdc3de80664a609527ec3d21e2 
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
29namespace android {
30
31class String8;
32
33class DataSource : public RefBase {
34public:
35    enum Flags {
36        kWantsPrefetching      = 1,
37        kStreamedFromLocalHost = 2,
38    };
39
40    static sp<DataSource> CreateFromURI(
41            const char *uri,
42            const KeyedVector<String8, String8> *headers = NULL);
43
44    DataSource() {}
45
46    virtual status_t initCheck() const = 0;
47
48    virtual ssize_t readAt(off_t offset, void *data, size_t size) = 0;
49
50    // Convenience methods:
51    bool getUInt16(off_t offset, uint16_t *x);
52
53    // May return ERROR_UNSUPPORTED.
54    virtual status_t getSize(off_t *size);
55
56    virtual uint32_t flags() {
57        return 0;
58    }
59
60    ////////////////////////////////////////////////////////////////////////////
61
62    bool sniff(String8 *mimeType, float *confidence);
63
64    typedef bool (*SnifferFunc)(
65            const sp<DataSource> &source, String8 *mimeType, float *confidence);
66
67    static void RegisterSniffer(SnifferFunc func);
68    static void RegisterDefaultSniffers();
69
70protected:
71    virtual ~DataSource() {}
72
73private:
74    static Mutex gSnifferMutex;
75    static List<SnifferFunc> gSniffers;
76
77    DataSource(const DataSource &);
78    DataSource &operator=(const DataSource &);
79};
80
81}  // namespace android
82
83#endif  // DATA_SOURCE_H_
84