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 #include <media/stagefright/foundation/ADebug.h>
23 #include <media/stagefright/MediaErrors.h>
24 #include <utils/Errors.h>
25 #include <utils/KeyedVector.h>
26 #include <utils/List.h>
27 #include <utils/RefBase.h>
28 #include <utils/threads.h>
29 #include <drm/DrmManagerClient.h>
30
31 namespace android {
32
33 struct AMessage;
34 struct AString;
35 class IDataSource;
36 struct IMediaHTTPService;
37 class String8;
38 struct HTTPBase;
39
40 class DataSource : public RefBase {
41 public:
42 enum Flags {
43 kWantsPrefetching = 1,
44 kStreamedFromLocalHost = 2,
45 kIsCachingDataSource = 4,
46 kIsHTTPBasedSource = 8,
47 kIsLocalFileSource = 16,
48 };
49
50 static sp<DataSource> CreateFromURI(
51 const sp<IMediaHTTPService> &httpService,
52 const char *uri,
53 const KeyedVector<String8, String8> *headers = NULL,
54 String8 *contentType = NULL,
55 HTTPBase *httpSource = NULL);
56
57 static sp<DataSource> CreateMediaHTTP(const sp<IMediaHTTPService> &httpService);
58 static sp<DataSource> CreateFromIDataSource(const sp<IDataSource> &source);
59 static sp<DataSource> CreateFromFd(int fd, int64_t offset, int64_t length);
60
DataSource()61 DataSource() {}
62
63 virtual status_t initCheck() const = 0;
64
65 // Returns the number of bytes read, or -1 on failure. It's not an error if
66 // this returns zero; it just means the given offset is equal to, or
67 // beyond, the end of the source.
68 virtual ssize_t readAt(off64_t offset, void *data, size_t size) = 0;
69
70 // Convenience methods:
71 bool getUInt16(off64_t offset, uint16_t *x);
72 bool getUInt24(off64_t offset, uint32_t *x); // 3 byte int, returned as a 32-bit int
73 bool getUInt32(off64_t offset, uint32_t *x);
74 bool getUInt64(off64_t offset, uint64_t *x);
75
76 // Reads in "count" entries of type T into vector *x.
77 // Returns true if "count" entries can be read.
78 // If fewer than "count" entries can be read, return false. In this case,
79 // the output vector *x will still have those entries that were read. Call
80 // x->size() to obtain the number of entries read.
81 // The optional parameter chunkSize specifies how many entries should be
82 // read from the data source at one time into a temporary buffer. Increasing
83 // chunkSize can improve the performance at the cost of extra memory usage.
84 // The default value for chunkSize is set to read at least 4k bytes at a
85 // time, depending on sizeof(T).
86 template <typename T>
87 bool getVector(off64_t offset, Vector<T>* x, size_t count,
88 size_t chunkSize = (4095 / sizeof(T)) + 1);
89
90 // May return ERROR_UNSUPPORTED.
91 virtual status_t getSize(off64_t *size);
92
flags()93 virtual uint32_t flags() {
94 return 0;
95 }
96
toString()97 virtual String8 toString() {
98 return String8("<unspecified>");
99 }
100
reconnectAtOffset(off64_t)101 virtual status_t reconnectAtOffset(off64_t /*offset*/) {
102 return ERROR_UNSUPPORTED;
103 }
104
105 ////////////////////////////////////////////////////////////////////////////
106
107 // for DRM
108 virtual sp<DecryptHandle> DrmInitialization(const char * /*mime*/ = NULL) {
109 return NULL;
110 }
getDrmInfo(sp<DecryptHandle> &,DrmManagerClient **)111 virtual void getDrmInfo(sp<DecryptHandle> &/*handle*/, DrmManagerClient ** /*client*/) {};
112
getUri()113 virtual String8 getUri() {
114 return String8();
115 }
116
117 virtual String8 getMIMEType() const;
118
close()119 virtual void close() {};
120
121 // creates an IDataSource wrapper to the DataSource.
122 virtual sp<IDataSource> asIDataSource();
123
124 // returns a pointer to IDataSource if it is wrapped.
125 virtual sp<IDataSource> getIDataSource() const;
126
127 protected:
~DataSource()128 virtual ~DataSource() {}
129
130 private:
131 DataSource(const DataSource &);
132 DataSource &operator=(const DataSource &);
133 };
134
135 template <typename T>
getVector(off64_t offset,Vector<T> * x,size_t count,size_t chunkSize)136 bool DataSource::getVector(off64_t offset, Vector<T>* x, size_t count,
137 size_t chunkSize)
138 {
139 x->clear();
140 if (chunkSize == 0) {
141 return false;
142 }
143 if (count == 0) {
144 return true;
145 }
146
147 T tmp[chunkSize];
148 ssize_t numBytesRead;
149 size_t numBytesPerChunk = chunkSize * sizeof(T);
150 size_t i;
151
152 for (i = 0; i + chunkSize < count; i += chunkSize) {
153 // This loops is executed when more than chunkSize records need to be
154 // read.
155 numBytesRead = this->readAt(offset, (void*)&tmp, numBytesPerChunk);
156 if (numBytesRead == -1) { // If readAt() returns -1, there is an error.
157 return false;
158 }
159 if (numBytesRead < numBytesPerChunk) {
160 // This case is triggered when the stream ends before the whole
161 // chunk is read.
162 x->appendArray(tmp, (size_t)numBytesRead / sizeof(T));
163 return false;
164 }
165 x->appendArray(tmp, chunkSize);
166 offset += numBytesPerChunk;
167 }
168
169 // There are (count - i) more records to read.
170 // Right now, (count - i) <= chunkSize.
171 // We do the same thing as above, but with chunkSize replaced by count - i.
172 numBytesRead = this->readAt(offset, (void*)&tmp, (count - i) * sizeof(T));
173 if (numBytesRead == -1) {
174 return false;
175 }
176 x->appendArray(tmp, (size_t)numBytesRead / sizeof(T));
177 return x->size() == count;
178 }
179
180 } // namespace android
181
182 #endif // DATA_SOURCE_H_
183