/*
* 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 <drm_common_types.h>
/** 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 <code>DRM_file_*</code> 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:
* <table>
* <tr><td>RW</td><td>E</td><td>Maps-to</td></tr>
* <tr><td>00</td><td>0</td><td>Return #DRM_FILE_FAILURE</td></tr>
* <tr><td>00</td><td>1</td><td>Return #DRM_FILE_FAILURE</td></tr>
* <tr><td>01</td><td>0</td><td>Use fopen mode "w"</td></tr>
* <tr><td>01</td><td>1</td><td>Use fopen mode "a" and fseek to the start</td></tr>
* <tr><td>10</td><td>0</td><td>Return #DRM_FILE_FAILURE</td></tr>
* <tr><td>10</td><td>1</td><td>Use fopen mode "r"</td></tr>
* <tr><td>11</td><td>0</td><td>Use fopen mode "w+"</td></tr>
* <tr><td>11</td><td>1</td><td>Use fopen mode "r+"</td></tr>
* </table>
* @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__ */