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libisofs/src/fsource.h

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/*
* Copyright (c) 2007 Vreixo Formoso
*
* This file is part of the libisofs project; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation. See COPYING file for details.
*/
#ifndef LIBISO_FSOURCE_H_
#define LIBISO_FSOURCE_H_
/*
* Definitions for the file sources.
*/
/*
* Some functions here will be moved to libisofs.h when we expose Sources.
*/
#include <sys/stat.h>
#define ISO_LOCAL_FS_ID 1
#define ISO_IMAGE_FS_ID 2
#define ISO_ELTORITO_FS_ID 3
#define ISO_MEM_FS_ID 4
typedef struct Iso_File_Source IsoFileSource;
typedef struct Iso_Filesystem IsoFilesystem;
/**
* See IsoFilesystem->get_id() for info about this.
*/
extern unsigned int iso_fs_global_id;
struct Iso_Filesystem
{
/**
*
* @return
* 1 on success, < 0 on error
*/
int (*get_root)(IsoFilesystem *fs, IsoFileSource **root);
/**
*
* @return
* 1 success, < 0 error
* Error codes:
* ISO_FILE_ACCESS_DENIED
* ISO_FILE_BAD_PATH
* ISO_FILE_DOESNT_EXIST
* ISO_MEM_ERROR
* ISO_FILE_ERROR
* ISO_NULL_POINTER
*/
int (*get_by_path)(IsoFilesystem *fs, const char *path,
IsoFileSource **file);
/**
* Get filesystem identifier.
*
* If the filesystem is able to generate correct values of the st_dev
* and st_ino fields for the struct stat of each file, this should
* return an unique number, greater than 0.
*
* To get a identifier for your filesystem implementation you should
* use iso_fs_global_id, incrementing it by one each time.
*
* Otherwise, if you can't ensure values in the struct stat are valid,
* this should return 0.
*/
unsigned int (*get_id)(IsoFilesystem *fs);
void (*free)(IsoFilesystem *fs);
/* TODO each file will take a ref to IsoFilesystem, so maybe a 64bits
* integer is a better choose for this */
unsigned int refcount;
void *data;
};
typedef struct IsoFileSource_Iface
{
/**
* Get the path, relative to the filesystem this file source
* belongs to.
*
* @return
* the path of the FileSource inside the filesystem, it should be
* freed when no more needed.
*/
char* (*get_path)(IsoFileSource *src);
/**
* Get the name of the file, with the dir component of the path.
*
* @return
* the name of the file, it should be freed when no more needed.
*/
char* (*get_name)(IsoFileSource *src);
/**
* Get information about the file.
* @return
* 1 success, < 0 error
* Error codes:
* ISO_FILE_ACCESS_DENIED
* ISO_FILE_BAD_PATH
* ISO_FILE_DOESNT_EXIST
* ISO_MEM_ERROR
* ISO_FILE_ERROR
* ISO_NULL_POINTER
*/
int (*lstat)(IsoFileSource *src, struct stat *info);
/**
* Get information about the file. If the file is a symlink, the info
* returned refers to the destination.
*
* @return
* 1 success, < 0 error
* Error codes:
* ISO_FILE_ACCESS_DENIED
* ISO_FILE_BAD_PATH
* ISO_FILE_DOESNT_EXIST
* ISO_MEM_ERROR
* ISO_FILE_ERROR
* ISO_NULL_POINTER
*/
int (*stat)(IsoFileSource *src, struct stat *info);
/**
* Check if the process has access to read file contents. Note that this
* is not necessarily related with (l)stat functions. For example, in a
* filesystem implementation to deal with an ISO image, if the user has
* read access to the image it will be able to read all files inside it,
* despite of the particular permission of each file in the RR tree, that
* are what the above functions return.
*
* @return
* 1 if process has read access, < 0 on error
* Error codes:
* ISO_FILE_ACCESS_DENIED
* ISO_FILE_BAD_PATH
* ISO_FILE_DOESNT_EXIST
* ISO_MEM_ERROR
* ISO_FILE_ERROR
* ISO_NULL_POINTER
*/
int (*access)(IsoFileSource *src);
/**
* Opens the source.
* @return 1 on success, < 0 on error
* Error codes:
* ISO_FILE_ALREADY_OPENNED
* ISO_FILE_ACCESS_DENIED
* ISO_FILE_BAD_PATH
* ISO_FILE_DOESNT_EXIST
* ISO_MEM_ERROR
* ISO_FILE_ERROR
* ISO_NULL_POINTER
*/
int (*open)(IsoFileSource *src);
/**
* Close a previuously openned file
* @return 1 on success, < 0 on error
* Error codes:
* ISO_FILE_ERROR
* ISO_NULL_POINTER
* ISO_FILE_NOT_OPENNED
*/
int (*close)(IsoFileSource *src);
/**
* Attempts to read up to count bytes from the given source into
* the buffer starting at buf.
*
* The file src must be open() before calling this, and close() when no
* more needed. Not valid for dirs. On symlinks it reads the destination
* file.
*
* @return
* number of bytes read, 0 if EOF, < 0 on error
* Error codes:
* ISO_FILE_ERROR
* ISO_NULL_POINTER
* ISO_FILE_NOT_OPENNED
* ISO_WRONG_ARG_VALUE -> if count == 0
* ISO_FILE_IS_DIR
* ISO_MEM_ERROR
* ISO_INTERRUPTED
*/
int (*read)(IsoFileSource *src, void *buf, size_t count);
/**
* Read a directory.
*
* Each call to this function will return a new children, until we reach
* the end of file (i.e, no more children), in that case it returns 0.
*
* The dir must be open() before calling this, and close() when no more
* needed. Only valid for dirs.
*
* Note that "." and ".." children MUST NOT BE returned.
*
* @param child
* pointer to be filled with the given child. Undefined on error or OEF
* @return
* 1 on success, 0 if EOF (no more children), < 0 on error
* Error codes:
* ISO_FILE_ERROR
* ISO_NULL_POINTER
* ISO_FILE_NOT_OPENNED
* ISO_FILE_IS_NOT_DIR
* ISO_MEM_ERROR
*/
int (*readdir)(IsoFileSource *src, IsoFileSource **child);
/**
* Read the destination of a symlink. You don't need to open the file
* to call this.
*
* @param buf
* allocated buffer of at least bufsiz bytes.
* The dest. will be copied there, and it will be NULL-terminated
* @param bufsiz
* characters to be copied. Destination link will be truncated if
* it is larger than given size. This include the \0 character.
* @return
* 1 on success, < 0 on error
* Error codes:
* ISO_FILE_ERROR
* ISO_NULL_POINTER
* ISO_WRONG_ARG_VALUE -> if bufsiz <= 0
* ISO_FILE_IS_NOT_SYMLINK
* ISO_MEM_ERROR
* ISO_FILE_BAD_PATH
* ISO_FILE_DOESNT_EXIST
*
*/
int (*readlink)(IsoFileSource *src, char *buf, size_t bufsiz);
/**
* Get the filesystem for this source. No extra ref is added, so you
* musn't unref the IsoFilesystem.
*
* @return
* The filesystem, NULL on error
*/
IsoFilesystem* (*get_filesystem)(IsoFileSource *src);
/**
* Free implementation specific data. Should never be called by user.
* Use iso_file_source_unref() instead.
*/
void (*free)(IsoFileSource *src);
/*
* TODO #00004 Add a get_mime_type() function.
* This can be useful for GUI apps, to choose the icon of the file
*/
} IsoFileSourceIface;
struct Iso_File_Source
{
const IsoFileSourceIface *class;
int refcount;
void *data;
};
void iso_file_source_ref(IsoFileSource *src);
void iso_file_source_unref(IsoFileSource *src);
/*
* this are just helpers to invoque methods in class
*/
/**
* Get the path, relative to the filesystem this file source
* belongs to.
*
* @return
* the path of the FileSource inside the filesystem, it should be
* freed when no more needed.
*/
char* iso_file_source_get_path(IsoFileSource *src);
/**
* Get the name of the file, with the dir component of the path.
*
* @return
* the name of the file, it should be freed when no more needed.
*/
char* iso_file_source_get_name(IsoFileSource *src);
/**
* Get information about the file.
* @return
* 1 success, < 0 error
* Error codes:
* ISO_FILE_ACCESS_DENIED
* ISO_FILE_BAD_PATH
* ISO_FILE_DOESNT_EXIST
* ISO_MEM_ERROR
* ISO_FILE_ERROR
* ISO_NULL_POINTER
*/
int iso_file_source_lstat(IsoFileSource *src, struct stat *info);
/**
* Check if the process has access to read file contents. Note that this
* is not necessarily related with (l)stat functions. For example, in a
* filesystem implementation to deal with an ISO image, if the user has
* read access to the image it will be able to read all files inside it,
* despite of the particular permission of each file in the RR tree, that
* are what the above functions return.
*
* @return
* 1 if process has read access, < 0 on error
* Error codes:
* ISO_FILE_ACCESS_DENIED
* ISO_FILE_BAD_PATH
* ISO_FILE_DOESNT_EXIST
* ISO_MEM_ERROR
* ISO_FILE_ERROR
* ISO_NULL_POINTER
*/
int iso_file_source_access(IsoFileSource *src);
/**
* Get information about the file. If the file is a symlink, the info
* returned refers to the destination.
*
* @return
* 1 success, < 0 error
* Error codes:
* ISO_FILE_ACCESS_DENIED
* ISO_FILE_BAD_PATH
* ISO_FILE_DOESNT_EXIST
* ISO_MEM_ERROR
* ISO_FILE_ERROR
* ISO_NULL_POINTER
*/
int iso_file_source_stat(IsoFileSource *src, struct stat *info);
/**
* Opens the source.
* @return 1 on success, < 0 on error
* Error codes:
* ISO_FILE_ALREADY_OPENNED
* ISO_FILE_ACCESS_DENIED
* ISO_FILE_BAD_PATH
* ISO_FILE_DOESNT_EXIST
* ISO_MEM_ERROR
* ISO_FILE_ERROR
* ISO_NULL_POINTER
*/
int iso_file_source_open(IsoFileSource *src);
/**
* Close a previuously openned file
* @return 1 on success, < 0 on error
* Error codes:
* ISO_FILE_ERROR
* ISO_NULL_POINTER
* ISO_FILE_NOT_OPENNED
*/
int iso_file_source_close(IsoFileSource *src);
/**
* Attempts to read up to count bytes from the given source into
* the buffer starting at buf.
*
* The file src must be open() before calling this, and close() when no
* more needed. Not valid for dirs. On symlinks it reads the destination
* file.
*
* @return
* number of bytes read, 0 if EOF, < 0 on error
* Error codes:
* ISO_FILE_ERROR
* ISO_NULL_POINTER
* ISO_FILE_NOT_OPENNED
* ISO_WRONG_ARG_VALUE -> if count == 0
* ISO_FILE_IS_DIR
* ISO_MEM_ERROR
* ISO_INTERRUPTED
*/
int iso_file_source_read(IsoFileSource *src, void *buf, size_t count);
/**
* Read a directory.
*
* Each call to this function will return a new children, until we reach
* the end of file (i.e, no more children), in that case it returns 0.
*
* The dir must be open() before calling this, and close() when no more
* needed. Only valid for dirs.
*
* Note that "." and ".." children MUST NOT BE returned.
*
* @param child
* pointer to be filled with the given child. Undefined on error or OEF
* @return
* 1 on success, 0 if EOF (no more children), < 0 on error
* Error codes:
* ISO_FILE_ERROR
* ISO_NULL_POINTER
* ISO_FILE_NOT_OPENNED
* ISO_FILE_IS_NOT_DIR
* ISO_MEM_ERROR
*/
int iso_file_source_readdir(IsoFileSource *src, IsoFileSource **child);
/**
* Read the destination of a symlink. You don't need to open the file
* to call this.
*
* @param buf
* allocated buffer of at least bufsiz bytes.
* The dest. will be copied there, and it will be NULL-terminated
* @param bufsiz
* characters to be copied. Destination link will be truncated if
* it is larger than given size. This include the \0 character.
* @return
* 1 on success, < 0 on error
* Error codes:
* ISO_FILE_ERROR
* ISO_NULL_POINTER
* ISO_WRONG_ARG_VALUE -> if bufsiz <= 0
* ISO_FILE_IS_NOT_SYMLINK
* ISO_MEM_ERROR
* ISO_FILE_BAD_PATH
* ISO_FILE_DOESNT_EXIST
*
*/
int iso_file_source_readlink(IsoFileSource *src, char *buf, size_t bufsiz);
/**
* Get the filesystem for this source. No extra ref is added, so you
* musn't unref the IsoFilesystem.
*
* @return
* The filesystem, NULL on error
*/
IsoFilesystem* iso_file_source_get_filesystem(IsoFileSource *src);
void iso_filesystem_ref(IsoFilesystem *fs);
void iso_filesystem_unref(IsoFilesystem *fs);
/**
* Create a new IsoFilesystem to deal with local filesystem.
*
* @return
* 1 sucess, < 0 error
*/
int iso_local_filesystem_new(IsoFilesystem **fs);
#endif /*LIBISO_FSOURCE_H_*/