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 // read either int<N> or int<2N> into a uint<2N>_t, size is the int size in bytes.
77 bool getUInt16Var(off64_t offset, uint16_t *x, size_t size);
78 bool getUInt32Var(off64_t offset, uint32_t *x, size_t size);
79 bool getUInt64Var(off64_t offset, uint64_t *x, size_t size);
80
81 // Reads in "count" entries of type T into vector *x.
82 // Returns true if "count" entries can be read.
83 // If fewer than "count" entries can be read, return false. In this case,
84 // the output vector *x will still have those entries that were read. Call
85 // x->size() to obtain the number of entries read.
86 // The optional parameter chunkSize specifies how many entries should be
87 // read from the data source at one time into a temporary buffer. Increasing
88 // chunkSize can improve the performance at the cost of extra memory usage.
89 // The default value for chunkSize is set to read at least 4k bytes at a
90 // time, depending on sizeof(T).
91 template <typename T>
92 bool getVector(off64_t offset, Vector<T>* x, size_t count,
93 size_t chunkSize = (4095 / sizeof(T)) + 1);
94
95 // May return ERROR_UNSUPPORTED.
96 virtual status_t getSize(off64_t *size);
97
flags()98 virtual uint32_t flags() {
99 return 0;
100 }
101
toString()102 virtual String8 toString() {
103 return String8("<unspecified>");
104 }
105
reconnectAtOffset(off64_t)106 virtual status_t reconnectAtOffset(off64_t /*offset*/) {
107 return ERROR_UNSUPPORTED;
108 }
109
110 ////////////////////////////////////////////////////////////////////////////
111
112 // for DRM
113 virtual sp<DecryptHandle> DrmInitialization(const char * /*mime*/ = NULL) {
114 return NULL;
115 }
getDrmInfo(sp<DecryptHandle> &,DrmManagerClient **)116 virtual void getDrmInfo(sp<DecryptHandle> &/*handle*/, DrmManagerClient ** /*client*/) {};
117
getUri()118 virtual String8 getUri() {
119 return String8();
120 }
121
122 virtual String8 getMIMEType() const;
123
close()124 virtual void close() {};
125
126 // creates an IDataSource wrapper to the DataSource.
127 virtual sp<IDataSource> asIDataSource();
128
129 // returns a pointer to IDataSource if it is wrapped.
130 virtual sp<IDataSource> getIDataSource() const;
131
132 protected:
~DataSource()133 virtual ~DataSource() {}
134
135 private:
136 DataSource(const DataSource &);
137 DataSource &operator=(const DataSource &);
138 };
139
140 template <typename T>
getVector(off64_t offset,Vector<T> * x,size_t count,size_t chunkSize)141 bool DataSource::getVector(off64_t offset, Vector<T>* x, size_t count,
142 size_t chunkSize)
143 {
144 x->clear();
145 if (chunkSize == 0) {
146 return false;
147 }
148 if (count == 0) {
149 return true;
150 }
151
152 T tmp[chunkSize];
153 ssize_t numBytesRead;
154 size_t numBytesPerChunk = chunkSize * sizeof(T);
155 size_t i;
156
157 for (i = 0; i + chunkSize < count; i += chunkSize) {
158 // This loops is executed when more than chunkSize records need to be
159 // read.
160 numBytesRead = this->readAt(offset, (void*)&tmp, numBytesPerChunk);
161 if (numBytesRead == -1) { // If readAt() returns -1, there is an error.
162 return false;
163 }
164 if (static_cast<size_t>(numBytesRead) < numBytesPerChunk) {
165 // This case is triggered when the stream ends before the whole
166 // chunk is read.
167 x->appendArray(tmp, (size_t)numBytesRead / sizeof(T));
168 return false;
169 }
170 x->appendArray(tmp, chunkSize);
171 offset += numBytesPerChunk;
172 }
173
174 // There are (count - i) more records to read.
175 // Right now, (count - i) <= chunkSize.
176 // We do the same thing as above, but with chunkSize replaced by count - i.
177 numBytesRead = this->readAt(offset, (void*)&tmp, (count - i) * sizeof(T));
178 if (numBytesRead == -1) {
179 return false;
180 }
181 x->appendArray(tmp, (size_t)numBytesRead / sizeof(T));
182 return x->size() == count;
183 }
184
185 } // namespace android
186
187 #endif // DATA_SOURCE_H_
188