1 /* 2 * Copyright (C) 2010 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 __FWDLOCKFILE_H__ 18 #define __FWDLOCKFILE_H__ 19 20 #ifdef __cplusplus 21 extern "C" { 22 #endif 23 24 #include <sys/types.h> 25 26 /** 27 * Attaches to an open Forward Lock file. The file position is assumed to be at the beginning of the 28 * file. 29 * 30 * @param[in] fileDesc The file descriptor of an open Forward Lock file. 31 * 32 * @return A status code. 33 * @retval 0 Success. 34 * @retval -1 Failure. 35 */ 36 int FwdLockFile_attach(int fileDesc); 37 38 /** 39 * Reads the specified number of bytes from an open Forward Lock file. 40 * 41 * @param[in] fileDesc The file descriptor of an open Forward Lock file. 42 * @param[out] pBuffer A reference to the buffer that should receive the read data. 43 * @param[in] numBytes The number of bytes to read. 44 * 45 * @return The number of bytes read. 46 * @retval -1 Failure. 47 */ 48 ssize_t FwdLockFile_read(int fileDesc, void *pBuffer, size_t numBytes); 49 50 /** 51 * Updates the file position within an open Forward Lock file. 52 * 53 * @param[in] fileDesc The file descriptor of an open Forward Lock file. 54 * @param[in] offset The offset with which to update the file position. 55 * @param[in] whence One of SEEK_SET, SEEK_CUR, and SEEK_END. 56 * 57 * @return The new file position. 58 * @retval ((off64_t)-1) Failure. 59 */ 60 off64_t FwdLockFile_lseek(int fileDesc, off64_t offset, int whence); 61 62 /** 63 * Detaches from an open Forward Lock file. 64 * 65 * @param[in] fileDesc The file descriptor of an open Forward Lock file. 66 * 67 * @return A status code. 68 * @retval 0 Success. 69 * @retval -1 Failure. 70 */ 71 int FwdLockFile_detach(int fileDesc); 72 73 /** 74 * Closes an open Forward Lock file. 75 * 76 * @param[in] fileDesc The file descriptor of an open Forward Lock file. 77 * 78 * @return A status code. 79 * @retval 0 Success. 80 * @retval -1 Failure. 81 */ 82 int FwdLockFile_close(int fileDesc); 83 84 /** 85 * Checks the data integrity of an open Forward Lock file. 86 * 87 * @param[in] fileDesc The file descriptor of an open Forward Lock file. 88 * 89 * @return A Boolean value indicating whether the integrity check was successful. 90 */ 91 int FwdLockFile_CheckDataIntegrity(int fileDesc); 92 93 /** 94 * Checks the header integrity of an open Forward Lock file. 95 * 96 * @param[in] fileDesc The file descriptor of an open Forward Lock file. 97 * 98 * @return A Boolean value indicating whether the integrity check was successful. 99 */ 100 int FwdLockFile_CheckHeaderIntegrity(int fileDesc); 101 102 /** 103 * Checks both the data and header integrity of an open Forward Lock file. 104 * 105 * @param[in] fileDesc The file descriptor of an open Forward Lock file. 106 * 107 * @return A Boolean value indicating whether the integrity check was successful. 108 */ 109 int FwdLockFile_CheckIntegrity(int fileDesc); 110 111 /** 112 * Returns the content type of an open Forward Lock file. 113 * 114 * @param[in] fileDesc The file descriptor of an open Forward Lock file. 115 * 116 * @return 117 * A reference to the content type. The reference remains valid as long as the file is kept open. 118 */ 119 const char *FwdLockFile_GetContentType(int fileDesc); 120 121 #ifdef __cplusplus 122 } 123 #endif 124 125 #endif // __FWDLOCKFILE_H__ 126
