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 29 namespace android { 30 31 struct AMessage; 32 class String8; 33 34 class DataSource : public RefBase { 35 public: 36 enum Flags { 37 kWantsPrefetching = 1, 38 kStreamedFromLocalHost = 2, 39 kIsCachingDataSource = 4, 40 }; 41 42 static sp<DataSource> CreateFromURI( 43 const char *uri, 44 const KeyedVector<String8, String8> *headers = NULL); 45 46 DataSource() {} 47 48 virtual status_t initCheck() const = 0; 49 50 virtual ssize_t readAt(off_t offset, void *data, size_t size) = 0; 51 52 // Convenience methods: 53 bool getUInt16(off_t offset, uint16_t *x); 54 55 // May return ERROR_UNSUPPORTED. 56 virtual status_t getSize(off_t *size); 57 58 virtual uint32_t flags() { 59 return 0; 60 } 61 62 //////////////////////////////////////////////////////////////////////////// 63 64 bool sniff(String8 *mimeType, float *confidence, sp<AMessage> *meta); 65 66 // The sniffer can optionally fill in "meta" with an AMessage containing 67 // a dictionary of values that helps the corresponding extractor initialize 68 // its state without duplicating effort already exerted by the sniffer. 69 typedef bool (*SnifferFunc)( 70 const sp<DataSource> &source, String8 *mimeType, 71 float *confidence, sp<AMessage> *meta); 72 73 static void RegisterSniffer(SnifferFunc func); 74 static void RegisterDefaultSniffers(); 75 76 protected: 77 virtual ~DataSource() {} 78 79 private: 80 static Mutex gSnifferMutex; 81 static List<SnifferFunc> gSniffers; 82 83 DataSource(const DataSource &); 84 DataSource &operator=(const DataSource &); 85 }; 86 87 } // namespace android 88 89 #endif // DATA_SOURCE_H_ 90
