/* * Copyright (C) 2007 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /** * File Porting Layer. */ #ifndef __DRM_FILE_H__ #define __DRM_FILE_H__ #ifdef __cplusplus extern "C" { #endif #include /** Type value of a regular file or file name. */ #define DRM_FILE_ISREG 1 /** Type value of a directory or directory name. */ #define DRM_FILE_ISDIR 2 /** Type value of a filter name */ #define DRM_FILE_ISFILTER 3 /** Return code that indicates successful completion of an operation. */ #define DRM_FILE_SUCCESS 0 /** Indicates that an operation failed. */ #define DRM_FILE_FAILURE -1 /** Indicates that the a DRM_file_read() call reached the end of the file. */ #define DRM_FILE_EOF -2 /** Open for read access. */ #define DRM_FILE_MODE_READ 1 /** Open for write access. */ #define DRM_FILE_MODE_WRITE 2 #ifndef MAX_FILENAME_LEN /** Maximum number of characters that a filename may have. By default assumes * that the entry results of DRM_file_listNextEntry() are returned in the async state * buffer, after the #DRM_file_result_s, and calculates the maximum name * from that. */ #define MAX_FILENAME_LEN 1024 #endif /** * Performs one-time initialization of the File System (FS). * This function is called once during the lifetime of an application, * and before any call to DRM_file_* functions by this application. * When several applications are using the file interface, this function may be called * several times, once per application. * * @return #DRM_FILE_SUCCESS, #DRM_FILE_FAILURE. */ int32_t DRM_file_startup(void); /** * Returns the length of a file (by name, opened or unopened). * * @param name Name of the file, UCS-2 encoded. * @param nameChars Number characters encoded in name. * asynchronous operation returns #DRM_FILE_WOULDBLOCK. * @return #DRM_FILE_WOULDBLOCK, #DRM_FILE_FAILURE or the file length. */ int32_t DRM_file_getFileLength(const uint16_t* name, int32_t nameChars); /** * Initializes a list iteration session. * * @param prefix Prefix that must be matched, UCS-2 encoded. * * @param prefixChars Number characters encoded in prefix. * @param session List session identifier. * @param iteration List iteration identifier. * * @return #DRM_FILE_WOULDBLOCK, #DRM_FILE_SUCCESS, #DRM_FILE_FAILURE. */ int32_t DRM_file_listOpen(const uint16_t* prefix, int32_t prefixChars, int32_t* session, int32_t* iteration); /** * Used to fetch a list of file names that match a given name prefix. * * @param prefix See DRM_file_listOpen(). This does not change during the * iteration session. * @param prefixChars See DRM_file_listOpen(). This does not change during * the iteration session. * @param entry Buffer parameter to return the next file name that matches the * #prefix parameter, if any, when the function returns a positive number of * characters. * @param entryBytes Size of entry in bytes. * @param session See DRM_file_listOpen(). * @param iteration See DRM_file_listOpen(). * @return #DRM_FILE_WOULDBLOCK, #DRM_FILE_FAILURE or the number of * characters encoded in entry. Returns 0 when the end of the list is reached. */ int32_t DRM_file_listNextEntry(const uint16_t* prefix, int32_t prefixChars, uint16_t* entry, int32_t entryBytes, int32_t* session, int32_t* iteration); /** * Ends a list iteration session. Notifies the implementation * that the list session is over and that any session resources * can be released. * * @param session See DRM_file_listOpen(). * @param iteration See DRM_file_listOpen(). * @return #DRM_FILE_WOULDBLOCK, #DRM_FILE_SUCCESS, #DRM_FILE_FAILURE. */ int32_t DRM_file_listClose(int32_t session, int32_t iteration); /** * Renames a file, given its old name. The file or directory is renamed * immediately on the actual file system upon invocation of this method. * Any open handles on the file specified by oldName become invalid after * this method has been called. * * @param oldName Current file name (unopened), UCS-2 encoded. * @param oldNameChars Number of characters encoded on oldName. * @param newName New name for the file (unopened), UCS-2 encoded. * @param newNameChars Number of characters encoded on newName. * @return #DRM_FILE_WOULDBLOCK, #DRM_FILE_SUCCESS, #DRM_FILE_FAILURE. In particular, * #DRM_FILE_FAILURE if a file or directory already exists with the new name. */ int32_t DRM_file_rename(const uint16_t* oldName, int32_t oldNameChars, const uint16_t* newName, int32_t newNameChars); /** * Tests if a file exists given its name. * * @param name Name of the file, UCS-2 encoded. * @param nameChars Number of characters encoded in name. * @return #DRM_FILE_WOULDBLOCK, #DRM_FILE_ISREG, #DRM_FILE_ISDIR, #DRM_FILE_FAILURE. If name * exists, returns #DRM_FILE_ISREG if it is a regular file and #DRM_FILE_ISDIR if it is a directory. * Returns #DRM_FILE_FAILURE in all other cases, including those where name exists but is neither * a regular file nor a directory. Platforms that do not support directories MUST NOT return * #DRM_FILE_ISDIR. */ int32_t DRM_file_exists(const uint16_t* name, int32_t nameChars); /** * Opens a file with the given name and returns its file handle. * * @param name Name of the file, UCS-2 encoded. * @param nameChars Number of characters encoded in name. * @param mode Any combination of the #DRM_FILE_MODE_READ and * #DRM_FILE_MODE_WRITE flags. If the file does not exist and mode contains the * #DRM_FILE_MODE_WRITE flag, then the file is automatically created. If the * file exists and the mode contains the #DRM_FILE_MODE_WRITE flag, the file is * opened so it can be modified, but the data is not modified by the open call. * In all cases the current position is set to the start of the file. * The following table shows how to map the mode semantics above to UNIX * fopen-style modes. For brevity in the table, R=#DRM_FILE_MODE_READ, * W=#DRM_FILE_MODE_WRITE, E=File exists: * * * * * * * * * * *
RWEMaps-to
000Return #DRM_FILE_FAILURE
001Return #DRM_FILE_FAILURE
010Use fopen mode "w"
011Use fopen mode "a" and fseek to the start
100Return #DRM_FILE_FAILURE
101Use fopen mode "r"
110Use fopen mode "w+"
111Use fopen mode "r+"
* @param handle Pointer where the result handle value is placed when the function * is called synchronously. * @return #DRM_FILE_WOULDBLOCK, #DRM_FILE_SUCCESS, #DRM_FILE_FAILURE. */ int32_t DRM_file_open(const uint16_t* name, int32_t nameChars, int32_t mode, int32_t* handle); /** * Deletes a file given its name, UCS-2 encoded. The file or directory is * deleted immediately on the actual file system upon invocation of this * method. Any open handles on the file specified by name become invalid * after this method has been called. * * If the port needs to ensure that a specific application does not exceed a given storage * space quota, then the bytes freed by the deletion must be added to the available space for * that application. * * @param name Name of the file, UCS-2 encoded. * @param nameChars Number of characters encoded in name. * @return #DRM_FILE_WOULDBLOCK, #DRM_FILE_SUCCESS, #DRM_FILE_FAILURE. */ int32_t DRM_file_delete(const uint16_t* name, int32_t nameChars); /** * Read bytes from a file at the current position to a buffer. Afterwards the * new file position is the byte after the last byte read. * DRM_FILE_FAILURE is returned if the handle is invalid (e.g., as a * consquence of DRM_file_delete, DRM_file_rename, or DRM_file_close). * * @param handle File handle as returned by DRM_file_open(). * @param dst Buffer where the data is to be copied. * @param length Number of bytes to be copied. * @return #DRM_FILE_WOULDBLOCK, #DRM_FILE_SUCCESS, #DRM_FILE_FAILURE, #DRM_FILE_EOF * or the number of bytes that were read, i.e. in the range 0..length. */ int32_t DRM_file_read(int32_t handle, uint8_t* dst, int32_t length); /** * Write bytes from a buffer to the file at the current position. If the * current position + number of bytes written > current size of the file, * then the file is grown. Afterwards the new file position is the byte * after the last byte written. * DRM_FILE_FAILURE is returned if the handle is invalid (e.g., as a * consquence of DRM_file_delete, DRM_file_rename, or DRM_file_close). * * @param handle File handle as returned by DRM_file_open(). * @param src Buffer that contains the bytes to be written. * @param length Number of bytes to be written. * If the port needs to ensure that a specific application does not exceed a given storage * space quota, the implementation must make sure the call does not violate that invariant. * @return #DRM_FILE_WOULDBLOCK, #DRM_FILE_FAILURE or the number of bytes * that were written. This number must be in the range 0..length. * Returns #DRM_FILE_FAILURE when storage is full or exceeds quota. */ int32_t DRM_file_write(int32_t handle, const uint8_t* src, int32_t length); /** * Closes a file. * DRM_FILE_SUCCESS is returned if the handle is invalid (e.g., as a * consquence of DRM_file_delete or DRM_file_rename). * * @param handle File handle as returned by DRM_file_open(). * @return #DRM_FILE_WOULDBLOCK, #DRM_FILE_SUCCESS, #DRM_FILE_FAILURE. */ int32_t DRM_file_close(int32_t handle); /** * Sets the current position in an opened file. * DRM_FILE_FAILURE is returned if the handle is invalid (e.g., as a * consquence of DRM_file_delete, DRM_file_rename, or DRM_file_close). * * @param handle File handle as returned by DRM_file_open(). * @param value The new current position of the file. If value is greater * than the length of the file then the file should be extended. The contents * of the newly extended portion of the file is undefined. * If the port needs to ensure that a specific application does not exceed a given storage * space quota, the implementation must make sure the call does not violate that invariant. * @return #DRM_FILE_WOULDBLOCK, #DRM_FILE_SUCCESS, #DRM_FILE_FAILURE. * Returns #DRM_FILE_FAILURE when storage is full or exceeds quota. */ int32_t DRM_file_setPosition(int32_t handle, int32_t value); /** * Creates a directory with the assigned name and full file permissions on * the file system. The full path to the new directory must already exist. * The directory is created immediately on the actual file system upon * invocation of this method. * * @param name Name of the directory, UCS-2 encoded. * @param nameChars Number of characters encoded in name. * @return #DRM_FILE_WOULDBLOCK, #DRM_FILE_SUCCESS, #DRM_FILE_FAILURE. */ int32_t DRM_file_mkdir(const uint16_t* name, int32_t nameChars); #ifdef __cplusplus } #endif #endif /* __DRM_FILE_H__ */