DataSource.h revision 5561ccf4a8db88a2e44eac1b3ed13b4ff53a7f20
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 }; 38 39 static sp<DataSource> CreateFromURI( 40 const char *uri, 41 const KeyedVector<String8, String8> *headers = NULL); 42 43 DataSource() {} 44 45 virtual status_t initCheck() const = 0; 46 47 virtual ssize_t readAt(off_t offset, void *data, size_t size) = 0; 48 49 // Convenience methods: 50 bool getUInt16(off_t offset, uint16_t *x); 51 52 // May return ERROR_UNSUPPORTED. 53 virtual status_t getSize(off_t *size); 54 55 virtual uint32_t flags() { 56 return 0; 57 } 58 59 //////////////////////////////////////////////////////////////////////////// 60 61 bool sniff(String8 *mimeType, float *confidence); 62 63 typedef bool (*SnifferFunc)( 64 const sp<DataSource> &source, String8 *mimeType, float *confidence); 65 66 static void RegisterSniffer(SnifferFunc func); 67 static void RegisterDefaultSniffers(); 68 69protected: 70 virtual ~DataSource() {} 71 72private: 73 static Mutex gSnifferMutex; 74 static List<SnifferFunc> gSniffers; 75 76 DataSource(const DataSource &); 77 DataSource &operator=(const DataSource &); 78}; 79 80} // namespace android 81 82#endif // DATA_SOURCE_H_ 83