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 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 93 virtual uint32_t flags() { 94 return 0; 95 } 96 97 virtual String8 toString() { 98 return String8("<unspecified>"); 99 } 100 101 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 } 111 virtual void getDrmInfo(sp<DecryptHandle> &/*handle*/, DrmManagerClient ** /*client*/) {}; 112 113 virtual String8 getUri() { 114 return String8(); 115 } 116 117 virtual String8 getMIMEType() const; 118 119 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: 128 virtual ~DataSource() {} 129 130 private: 131 DataSource(const DataSource &); 132 DataSource &operator=(const DataSource &); 133 }; 134 135 template <typename T> 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
