Module org.cryptomator.jfuse.api

Package org.cryptomator.jfuse.api

Interface FuseOperationsDecorator

All Superinterfaces:

FuseOperations

public interface FuseOperationsDecorator
extends FuseOperations

Convenience interface to make decorating FuseOperations easier.

Nested Class Summary

Nested classes/interfaces inherited from interface org.cryptomator.jfuse.api.FuseOperations

FuseOperations.Operation

Field Summary

Fields inherited from interface org.cryptomator.jfuse.api.FuseOperations

FUSE_READDIR_PLUS

Method Summary

Modifier and Type	Method	Description
default int	access(String path, int mask)	Check file access permissions.
default int	chmod(String path, int mode, @Nullable FileInfo fi)	Change the permission bits of a file
default int	chown(String path, int uid, int gid, @Nullable FileInfo fi)	Change the owner and group of a file
default int	create(String path, int mode, FileInfo fi)	Create and open a file.
FuseOperations	delegate()	Get the to-be-decorated FuseOperations object.
default void	destroy()	Clean up filesystem
default Errno	errno()	The error constants used by this file system.
default int	flush(String path, FileInfo fi)	Possibly flush cached data.
default int	fsync(String path, int datasync, FileInfo fi)	Synchronize file contents
default int	fsyncdir(@Nullable String path, int datasync, FileInfo fi)	Synchronize directory contents
default int	getattr(String path, Stat stat, @Nullable FileInfo fi)	Get file attributes.
default int	getxattr(String path, String name, ByteBuffer value)	Get extended attributes
default void	init(FuseConnInfo conn, @Nullable FuseConfig cfg)	Initialize filesystem
default int	link(String linkname, String target)	Create a hard link to a file
default int	listxattr(String path, ByteBuffer list)	List extended attributes
default int	mkdir(String path, int mode)	Create a directory.
default int	mknod(String path, short mode, int rdev)	Create a file node.
default int	open(String path, FileInfo fi)	Open a file.
default int	opendir(String path, FileInfo fi)	Open directory.
default int	read(String path, ByteBuffer buf, long count, long offset, FileInfo fi)	Read data from an open file.
default int	readdir(String path, DirFiller filler, long offset, FileInfo fi, int flags)	Read directory.
default int	readlink(String path, ByteBuffer buf, long len)	Read the target of a symbolic link.
default int	release(String path, FileInfo fi)	Release an open file.
default int	releasedir(@Nullable String path, FileInfo fi)	Release directory
default int	removexattr(String path, String name)	Remove extended attributes
default int	rename(String oldpath, String newpath, int flags)	Rename a file
default int	rmdir(String path)	Remove a directory
default int	setxattr(String path, String name, ByteBuffer value, int flags)	Set extended attributes
default int	statfs(String path, Statvfs statvfs)	Get file system statistics.
default Set<FuseOperations.Operation>	supportedOperations()	The supported file system operations.
default int	symlink(String linkname, String target)	Create a symbolic link
default int	truncate(String path, long size, @Nullable FileInfo fi)	Change the size of a file.
default int	unlink(String path)	Remove a file
default int	utimens(String path, TimeSpec atime, TimeSpec mtime, @Nullable FileInfo fi)	Change the access and modification times of a file with nanosecond resolution.
default int	write(String path, ByteBuffer buf, long count, long offset, FileInfo fi)	Write data to an open file.

Methods inherited from interface org.cryptomator.jfuse.api.FuseOperations

fallocate, flock, ioctl

Method Details

delegate

FuseOperations delegate()

Get the to-be-decorated FuseOperations object.

Returns:

the undecorated operations

supportedOperations

default Set<FuseOperations.Operation> supportedOperations()

Description copied from interface: FuseOperations

The supported file system operations.

Specified by:

supportedOperations in interface FuseOperations

Returns:

The set of supported operations.

errno

default Errno errno()

Description copied from interface: FuseOperations

The error constants used by this file system.

Specified by:

errno in interface FuseOperations

Returns:

The error codes from errno.h for the current platform.

See Also:

• FuseBuilder.errno()

getattr

default int getattr(String path,
 Stat stat,
 @Nullable
 @Nullable FileInfo fi)

Description copied from interface: FuseOperations

Get file attributes.

Similar to stat(). The 'st_dev' and 'st_blksize' fields are ignored. The 'st_ino' field is ignored except if the 'use_ino' mount option is given. In that case it is passed to userspace, but libfuse and the kernel will still assign a different inode for internal use (called the "nodeid").

This method doubles as fgetattr in libfuse2

Specified by:

getattr in interface FuseOperations

Parameters:

path - file path

stat - file information

fi - will always be null if the file is not currently open, but may also be null if the file is open.

Returns:

0 on success or negated error code (-errno)

getxattr

default int getxattr(String path,
 String name,
 ByteBuffer value)

Description copied from interface: FuseOperations

Get extended attributes

Specified by:

getxattr in interface FuseOperations

Parameters:

path - file path

name - attribute name

value - attribute value. If buffer capacity is zero, return the size of the value

Returns:

the non-negative value size or negated error code (-errno)

setxattr

default int setxattr(String path,
 String name,
 ByteBuffer value,
 int flags)

Description copied from interface: FuseOperations

Set extended attributes

Specified by:

setxattr in interface FuseOperations

Parameters:

path - file path

name - attribute name

value - attribute value

flags - defaults to zero, which creates or replaces the attribute. For fine-grained atomic control, XATTR_CREATE or XATTR_REPLACE may be used.

Returns:

0 on success or negated error code (-errno)

listxattr

default int listxattr(String path,
 ByteBuffer list)

Description copied from interface: FuseOperations

List extended attributes

Specified by:

listxattr in interface FuseOperations

Parameters:

path - file path

list - consecutive list of null-terminated attribute names (as many as fit into the buffer). If buffer capacity is zero, return the size of the list

Returns:

the non-negative number of bytes written to the list buffer or negated error code (-errno)

removexattr

default int removexattr(String path,
 String name)

Description copied from interface: FuseOperations

Remove extended attributes

Specified by:

removexattr in interface FuseOperations

Parameters:

path - file path

name - attribute name

Returns:

0 on success or negated error code (-errno)

readlink

default int readlink(String path,
 ByteBuffer buf,
 long len)

Description copied from interface: FuseOperations

Read the target of a symbolic link.

Specified by:

readlink in interface FuseOperations

Parameters:

path - file path

buf - The buffer should be filled with a null terminated string.

len - The buffer size (including the terminating null character). If the linkname is too long to fit in the buffer, it should be truncated.

Returns:

The return value should be 0

mknod

default int mknod(String path,
 short mode,
 int rdev)

Description copied from interface: FuseOperations

Create a file node.

This is called for creation of all non-directory, non-symlink nodes. If the filesystem defines a create() method, then for regular files that will be called instead.

Specified by:

mknod in interface FuseOperations

Parameters:

path - file path

mode - file mode and type of node to create (using bitwise OR)

rdev - ignored if mode does not contain S_IFCHR or S_IFBLK

Returns:

0 on success or negated error code (-errno)

mkdir

default int mkdir(String path,
 int mode)

Description copied from interface: FuseOperations

Create a directory.

Note that the mode argument may not have the type specification bits set, i.e. S_ISDIR(mode) can be false. To obtain the correct directory type bits use mode|S_IFDIR

Specified by:

mkdir in interface FuseOperations

Parameters:

path - file path

mode - file mode (using bitwise OR)

Returns:

0 on success or negated error code (-errno)

unlink

default int unlink(String path)

Description copied from interface: FuseOperations

Remove a file

Specified by:

unlink in interface FuseOperations

Parameters:

path - file path

Returns:

0 on success or negated error code (-errno)

rmdir

default int rmdir(String path)

Description copied from interface: FuseOperations

Remove a directory

Specified by:

rmdir in interface FuseOperations

Parameters:

path - file path

Returns:

0 on success or negated error code (-errno)

symlink

default int symlink(String linkname,
 String target)

Description copied from interface: FuseOperations

Create a symbolic link

Specified by:

symlink in interface FuseOperations

Parameters:

linkname - file path

target - content of the link

Returns:

0 on success or negated error code (-errno)

rename

default int rename(String oldpath,
 String newpath,
 int flags)

Description copied from interface: FuseOperations

Rename a file

Specified by:

rename in interface FuseOperations

Parameters:

oldpath - old file path

newpath - new file path

flags - may be `RENAME_EXCHANGE` or `RENAME_NOREPLACE`. If RENAME_NOREPLACE is specified, the filesystem must not overwrite *newname* if it exists and return an error instead. If `RENAME_EXCHANGE` is specified, the filesystem must atomically exchange the two files, i.e. both must exist and neither may be deleted.

Returns:

0 on success or negated error code (-errno)

link

default int link(String linkname,
 String target)

Description copied from interface: FuseOperations

Create a hard link to a file

Specified by:

link in interface FuseOperations

Parameters:

linkname - file path

target - content of the link

Returns:

0 on success or negated error code (-errno)

chmod

default int chmod(String path,
 int mode,
 @Nullable
 @Nullable FileInfo fi)

Description copied from interface: FuseOperations

Change the permission bits of a file

Specified by:

chmod in interface FuseOperations

Parameters:

path - file path

mode - file mode (using bitwise OR)

fi - will always be null if the file is not currently open, but may also be null if the file is open.

Returns:

0 on success or negated error code (-errno)

chown

default int chown(String path,
 int uid,
 int gid,
 @Nullable
 @Nullable FileInfo fi)

Description copied from interface: FuseOperations

Change the owner and group of a file

Specified by:

chown in interface FuseOperations

Parameters:

path - file path

uid - user id

gid - group id

fi - will always be null if the file is not currently open, but may also be null if the file is open.

Returns:

0 on success or negated error code (-errno)

truncate

default int truncate(String path,
 long size,
 @Nullable
 @Nullable FileInfo fi)

Description copied from interface: FuseOperations

Change the size of a file.

Unless FUSE_CAP_HANDLE_KILLPRIV is disabled, this method is expected to reset the setuid and setgid bits.

This method doubles as ftruncate in libfuse2

Specified by:

truncate in interface FuseOperations

Parameters:

path - file path

size - new size of the file

fi - will always be null if the file is not currently open, but may also be null if the file is open.

Returns:

0 on success or negated error code (-errno)

open

default int open(String path,
 FileInfo fi)

Description copied from interface: FuseOperations

Open a file.

Open flags are available in fi->flags. The following rules apply.

• Creation (O_CREAT, O_EXCL, O_NOCTTY) flags will be filtered out / handled by the kernel.
• Access modes (O_RDONLY, O_WRONLY, O_RDWR, O_EXEC, O_SEARCH) should be used by the filesystem to check if the operation is permitted. If the ``-o default_permissions`` mount option is given, this check is already done by the kernel before calling open() and may thus be omitted by the filesystem.
• When writeback caching is enabled, the kernel may send read requests even for files opened with O_WRONLY. Thefilesystem should be prepared to handle this.
• When writeback caching is disabled, the filesystem is expected to properly handle the O_APPEND flag and ensurethat each write is appending to the end of the file.
• When writeback caching is enabled, the kernel will handle O_APPEND. However, unless all changes to the file come through the kernel this will not work reliably. The filesystem should thus either ignore the O_APPEND flag (and let the kernel handle it), or return an error (indicating that reliably O_APPEND is not available).

Filesystem may store an arbitrary file handle (pointer, index, etc) in fi->fh, and use this in other all other file operations (read, write, flush, release, fsync).

Filesystem may also implement stateless file I/O and not store anything in fi->fh.

There are also some flags (direct_io, keep_cache) which the filesystem may set in fi, to change the way the file is opened. See fuse_file_info structure in fuse_common.h for more details.

If this request is answered with an error code of ENOSYS and FUSE_CAP_NO_OPEN_SUPPORT is set in `fuse_conn_info.capable`, this is treated as success and future calls to open will also succeed without being send to the filesystem process.

Specified by:

open in interface FuseOperations

Parameters:

path - file path

fi - file info, which may be used to store a file handle

Returns:

0 on success or negated error code (-errno)

read

default int read(String path,
 ByteBuffer buf,
 long count,
 long offset,
 FileInfo fi)

Description copied from interface: FuseOperations

Read data from an open file.

Read should return exactly the number of bytes requested except on EOF or error, otherwise the rest of the data will be substituted with zeroes. An exception to this is when the 'direct_io' mount option is specified, in which case the return value of the read system call will reflect the return value of this operation.

Specified by:

read in interface FuseOperations

Parameters:

path - file path

buf - the buffer to read into

count - number of bytes to read

offset - position in the file to start reading

fi - file info

Returns:

number of bytes read or negated error code (-errno)

write

default int write(String path,
 ByteBuffer buf,
 long count,
 long offset,
 FileInfo fi)

Description copied from interface: FuseOperations

Write data to an open file.

Write should return exactly the number of bytes requested except on error. An exception to this is when the 'direct_io' mount option is specified (see read operation).

Unless FUSE_CAP_HANDLE_KILLPRIV is disabled, this method is expected to reset the setuid and setgid bits.

Specified by:

write in interface FuseOperations

Parameters:

path - file path

buf - the buffer containing the data to be written

count - number of bytes to write

offset - position in the file to write to

fi - file info

Returns:

number of bytes written or negated error code (-errno)

statfs

default int statfs(String path,
 Statvfs statvfs)

Description copied from interface: FuseOperations

Get file system statistics.

The 'f_favail', 'f_fsid' and 'f_flag' fields are ignored

Specified by:

statfs in interface FuseOperations

Parameters:

path - file path of any file within the file system

statvfs - The statistics object to be filled with data

Returns:

0 on success or negated error code (-errno)

flush

default int flush(String path,
 FileInfo fi)

Description copied from interface: FuseOperations

Possibly flush cached data.

BIG NOTE: This is not equivalent to fsync(). It's not a request to sync dirty data.

Flush is called on each close() of a file descriptor, as opposed to release which is called on the close of the last file descriptor for a file. Under Linux, errors returned by flush() will be passed to userspace as errors from close(), so flush() is a good place to write back any cached dirty data. However, many applications ignore errors on close(), and on non-Linux systems, close() may succeed even if flush() returns an error. For these reasons, filesystems should not assume that errors returned by flush will ever be noticed or even delivered.

NOTE: The flush() method may be called more than once for each open(). This happens if more than one file descriptor refers to an open file handle, e.g. due to dup(), dup2() or fork() calls. It is not possible to determine if a flush is final, so each flush should be treated equally. Multiple write-flush sequences are relatively rare, so this shouldn't be a problem.

Filesystems shouldn't assume that flush will be called at any particular point. It may be called more times than expected, or not at all.

Specified by:

flush in interface FuseOperations

Parameters:

path - file path

fi - file info

Returns:

0 on success or negated error code (-errno)

fsync

default int fsync(String path,
 int datasync,
 FileInfo fi)

Description copied from interface: FuseOperations

Synchronize file contents

Specified by:

fsync in interface FuseOperations

Parameters:

path - file path

datasync - if non-zero, then only the user data should be flushed, not the meta data.

fi - file info

Returns:

0 on success or negated error code (-errno)

release

default int release(String path,
 FileInfo fi)

Description copied from interface: FuseOperations

Release an open file.

Release is called when there are no more references to an open file: all file descriptors are closed and all memory mappings are unmapped.

For every open() call there will be exactly one release() call with the same flags and file handle. It is possible to have a file opened more than once, in which case only the last release will mean, that no more reads/writes will happen on the file. The return value of release is ignored.

Specified by:

release in interface FuseOperations

Parameters:

path - file path

fi - file info

Returns:

0 on success or negated error code (-errno)

opendir

default int opendir(String path,
 FileInfo fi)

Description copied from interface: FuseOperations

Open directory.

Unless the 'default_permissions' mount option is given, this method should check if opendir is permitted for this directory. Optionally opendir may also return an arbitrary filehandle in the fuse_file_info structure, which will be passed to readdir, releasedir and fsyncdir.

Specified by:

opendir in interface FuseOperations

Parameters:

path - directory path

fi - file info, which may be used to store a file handle

Returns:

0 on success or negated error code (-errno)

readdir

default int readdir(String path,
 DirFiller filler,
 long offset,
 FileInfo fi,
 int flags)

Description copied from interface: FuseOperations

Read directory.

The filesystem may choose between two modes of operation:

1. The readdir implementation ignores the offset parameter, and passes zero to the filler function's offset. The filler function will not return '1' (unless an error happens), so the whole directory is read in a single readdir operation.
2. The readdir implementation keeps track of the offsets of the directory entries. It uses the offset parameter and always passes non-zero offset to the filler function. When the buffer is full (or an error happens) the filler function will return '1'.

Specified by:

readdir in interface FuseOperations

Parameters:

path - directory path

filler - the fill function

offset - the offset

fi - file info

flags - When FuseOperations.FUSE_READDIR_PLUS is not set, only some parameters of the fill function (the filler parameter) are actually used: The file type (which is part of Stat.getMode()) is used. And if fuse_config::use_ino is set, the inode (stat::st_ino) is also used. The other fields are ignored when READ_DIR_PLUS is not set.

Returns:

0 on success or negated error code (-errno)

fsyncdir

default int fsyncdir(@Nullable
 @Nullable String path,
 int datasync,
 FileInfo fi)

Description copied from interface: FuseOperations

Synchronize directory contents

Specified by:

fsyncdir in interface FuseOperations

Parameters:

path - directory path. If the directory has been removed after the call to opendir, the path parameter will be null

datasync - if non-zero, then only the user data should be flushed, not the meta data

fi - file info

Returns:

0 on success or negated error code (-errno)

releasedir

default int releasedir(@Nullable
 @Nullable String path,
 FileInfo fi)

Description copied from interface: FuseOperations

Release directory

Specified by:

releasedir in interface FuseOperations

Parameters:

path - directory path. If the directory has been removed after the call to opendir, the path parameter will be null

fi - file info

Returns:

0 on success or negated error code (-errno)

init

default void init(FuseConnInfo conn,
 @Nullable
 @Nullable FuseConfig cfg)

Description copied from interface: FuseOperations

Initialize filesystem

Specified by:

init in interface FuseOperations

Parameters:

conn - FUSE connection information

cfg - FUSE configuration object

destroy

default void destroy()

Description copied from interface: FuseOperations

Clean up filesystem

Called on filesystem exit.

Specified by:

destroy in interface FuseOperations

access

default int access(String path,
 int mask)

Description copied from interface: FuseOperations

Check file access permissions.

This will be called for the access() system call. If the 'default_permissions' mount option is given, this method is not called.

This method is not called under Linux kernel versions 2.4.x

Specified by:

access in interface FuseOperations

Parameters:

path - file path

mask - bitwise OR of file access checks

Returns:

0 on success or negated error code (-errno)

create

default int create(String path,
 int mode,
 FileInfo fi)

Description copied from interface: FuseOperations

Create and open a file.

If the file does not exist, first create it with the specified mode, and then open it.

If this method is not implemented or under Linux kernel versions earlier than 2.6.15, the mknod() and open() methods will be called instead.

Specified by:

create in interface FuseOperations

Parameters:

path - file path

mode - mode used to create the file if it does not exist yet

fi - file info, which may be used to store a file handle

Returns:

0 on success or negated error code (-errno)

utimens

default int utimens(String path,
 TimeSpec atime,
 TimeSpec mtime,
 @Nullable
 @Nullable FileInfo fi)

Description copied from interface: FuseOperations

Change the access and modification times of a file with nanosecond resolution.

This supersedes the old utime() interface. New applications should use this.

See the utimensat(2) man page for details.

Specified by:

utimens in interface FuseOperations

Parameters:

path - file path

atime - last access time

mtime - last modified time

fi - will always be null if the file is not currently open, but may also be null if the file is open.

Returns:

0 on success or negated error code (-errno)