File.h revision c72c4ddfcd79c74f70713da91a69569451b5c19e
1/* 2 * Copyright 2012, 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 BCC_SUPPORT_FILE_H 18#define BCC_SUPPORT_FILE_H 19 20#include "bcc/Support/FileBase.h" 21 22namespace bcc { 23 24template<enum FileBase::OpenModeEnum OpenMode> 25struct FileAttribute { 26 // The flags to the 2nd argument in ::open(). 27 enum { kOpenFlags }; 28 29 // Default value of LockMode. 30 enum { kDefaultLockMode }; 31}; 32 33// FileAttribute for accessing read-only file 34template<> 35struct FileAttribute<FileBase::kReadMode> { 36 enum { kOpenFlags = O_RDONLY }; 37 enum { kDefaultLockMode = FileBase::kReadLock }; 38}; 39 40// FileAttribute for accessing writable file 41template<> 42struct FileAttribute<FileBase::kWriteMode> { 43 enum { kOpenFlags = O_RDWR | O_CREAT | O_TRUNC }; 44 enum { kDefaultLockMode = FileBase::kWriteLock }; 45}; 46 47template<enum FileBase::OpenModeEnum OpenMode> 48class File : public FileBase { 49public: 50 File(const std::string &pFilename, unsigned pFlags) 51 : FileBase(pFilename, FileAttribute<OpenMode>::kOpenFlags, pFlags) { } 52 53 inline bool lock(enum LockModeEnum pMode = static_cast<enum LockModeEnum>( 54 FileAttribute<OpenMode>::kDefaultLockMode), 55 bool pNonblocking = true, 56 unsigned pMaxRetry = FileBase::kDefaultMaxRetryLock, 57 useconds_t pRetryInterval = 58 FileBase::kDefaultRetryLockInterval) { 59 return FileBase::lock(pMode, pNonblocking, pMaxRetry, pRetryInterval); 60 } 61 62 inline android::FileMap *createMap(off_t pOffset, size_t pLength, 63 bool pIsReadOnly = 64 (OpenMode == FileBase::kReadMode)) { 65 return FileBase::createMap(pOffset, pLength, pIsReadOnly); 66 } 67}; 68 69 70} // end namespace bcc 71 72#endif // BCC_SUPPORT_FILE_H 73