#
# This file is part of Config-Model
#
# This software is Copyright (c) 2005-2016 by Dominique Dumont.
#
# This is free software, licensed under:
#
# The GNU Lesser General Public License, Version 2.1, February 1999
#
package Config::Model::FuseUI;
$Config::Model::FuseUI::VERSION = '2.094';
# there's no Singleton with Mouse
use Mouse;
use Fuse qw(fuse_get_context);
use Fcntl ':mode';
use POSIX qw(ENOENT EISDIR EINVAL);
use Log::Log4perl qw(get_logger :levels);
use English qw( -no_match_vars );
has model => ( is => 'rw', isa => 'Config::Model' );
has root => ( is => 'ro', isa => 'Config::Model::Node', required => 1 );
has mountpoint => ( is => 'ro', isa => 'Str', required => 1 );
my $logger = get_logger("FuseUI");
has dir_char_mockup => ( is => 'ro', isa => 'Str', default => '<slash>' );
our $fuseui;
my $dir_char_mockup;
sub BUILD {
my $self = shift;
croak( __PACKAGE__, " singleton constructed twice" )
if defined $fuseui and $fuseui ne $self;
$fuseui = $self; # store singleton object in global variable
$dir_char_mockup = $self->dir_char_mockup;
}
# nodes, list and hashes are directories
sub getdir {
my $name = shift;
$logger->debug("FuseUI getdir called with $name");
my $obj = get_object($name);
return -EINVAL() unless ( ref $obj and $obj->can('children') );
my @c = ( '..', '.', $obj->children );
map { s(/)($dir_char_mockup)g } @c;
$logger->debug( "FuseUI getdir return @c , wantarray is " . ( wantarray ? 1 : 0 ) );
return ( @c, 0 );
}
my %files;
sub fetch_as_line {
my $obj = shift;
my $v = $obj->fetch( check => 'no' );
$v = '' unless defined $v;
# let's append a \n so that returned files always have a line ending
$v .= "\n" unless $v =~ /\n$/;
return $v;
}
sub get_object {
my $name = shift;
return _get_object( $name, 0 );
}
sub get_or_create_object {
my $name = shift;
return _get_object( $name, 1 );
}
sub _get_object {
my ( $name, $autoadd ) = @_;
my $obj = $fuseui->root->get(
path => $name,
check => 'skip',
get_obj => 1,
autoadd => $autoadd,
dir_char_mockup => $dir_char_mockup
);
$logger->debug( "FuseUI _get_object on $name returns ",
( defined $obj ? $obj->name : '<undef>' ) );
return $obj;
}
sub getattr {
my $name = shift;
$logger->debug("FuseUI getattr called with $name");
my $obj = get_object($name);
return -&ENOENT() unless ref $obj;
my $type = $obj->get_type;
# return -ENOENT() unless exists($files{$file});
my $size;
if ( $type eq 'leaf' or $type eq 'check_list' ) {
$size = length( fetch_as_line($obj) );
}
else {
my @c = $obj->children;
map { s(/)($dir_char_mockup)g } @c;
$size = @c;
}
my $mode;
if ( $type eq 'leaf' or $type eq 'check_list' ) {
$mode = S_IFREG | 0644;
}
else {
$mode = S_IFDIR | 0755;
}
my ( $dev, $ino, $rdev, $blocks, $gid, $uid, $nlink, $blksize ) =
( 0, 0, 0, 1, $EGID, $EUID, 1, 1024 );
my ( $atime, $ctime, $mtime );
$atime = $ctime = $mtime = time;
# 2 possible types of return values:
#return -ENOENT(); # or any other error you care to
#print(join(",",($dev,$ino,$modes,$nlink,$uid,$gid,$rdev,$size,$atime,$mtime,$ctime,$blksize,$blocks)),"\n");
my @r = (
$dev, $ino, $mode, $nlink, $uid, $gid, $rdev,
$size, $atime, $mtime, $ctime, $blksize, $blocks
);
$logger->trace( "FuseUI getattr returns '" . join( "','", @r ) . "'" );
return @r;
}
sub open {
# VFS sanity check; it keeps all the necessary state, not much to do here.
my $name = shift;
$logger->debug("FuseUI open called on $name");
my $obj = $fuseui->root->get( path => $name, check => 'skip', get_obj => 1 );
my $type = $obj->get_type;
return -ENOENT() unless defined $obj;
return -EISDIR() unless ( $type eq 'leaf' or $type eq 'check_list' );
$logger->debug("FuseUI open on $name ok");
return 0;
}
sub read {
# return an error numeric, or binary/text string. (note: 0 means EOF, "0" will
# give a byte (ascii "0") to the reading program)
my ( $name, $buf, $off ) = @_;
$logger->debug("FuseUI read called on $name");
my $obj = get_or_create_object($name);
my $type = $obj->get_type;
return -ENOENT() unless defined $obj;
return -EISDIR() unless ( $type eq 'leaf' or $type eq 'check_list' );
my $v = fetch_as_line($obj);
if ( not defined $v ) {
return -EINVAL() if $off > 0;
return '';
}
return -EINVAL() if $off > length($v);
return 0 if $off == length($v);
my $ret = substr( $v, $off, $buf );
$logger->debug("FuseUI read returns '$ret'");
return "$ret";
}
sub truncate {
my ( $name, $off ) = @_;
$logger->debug("FuseUI truncate called on $name with length $off");
my $obj = get_or_create_object($name);
my $type = $obj->get_type;
return -ENOENT() unless defined $obj;
return -EISDIR() unless ( $type eq 'leaf' or $type eq 'check_list' );
my $v = substr fetch_as_line($obj), 0, $off;
$logger->debug( "FuseUI truncate stores '$v' of length ", length($v) );
# store the value without any check. Check will be done in write()
# the second parameter will trigger a notif_change.
$obj->_store_value( $v, 1 );
return 0;
}
sub write {
my ( $name, $buf, $off ) = @_;
if ( $logger->is_debug ) {
my $str = $buf;
$str =~ s/\n/\\n/g;
$logger->debug("FuseUI write called on $name with '$str' offset $off");
}
my $obj = get_or_create_object($name);
my $type = $obj->get_type;
return -ENOENT() unless defined $obj;
return -EISDIR() unless ( $type eq 'leaf' or $type eq 'check_list' );
my $v = fetch_as_line($obj);
$logger->debug("FuseUI write starts with '$v'");
substr $v, $off, length($buf), $buf;
chomp $v unless ( $type eq 'leaf' and $obj->value_type eq 'string' );
$logger->debug("FuseUI write stores '$v'");
$obj->store( value => $v, check => 'skip', say_dont_warn => 1 );
return length($buf);
}
sub mkdir {
# return an error numeric, or binary/text string. (note: 0 means EOF, "0" will
# give a byte (ascii "0") to the reading program)
my ( $name, $mode ) = @_;
$logger->debug("FuseUI mkdir called on $name with mode $mode");
my $obj = get_or_create_object($name);
return -ENOENT() unless defined $obj;
my $type = $obj->container_type;
return -ENOENT() unless ( $type eq 'list' or $type eq 'hash' );
return 0;
}
sub rmdir {
# return an error numeric, or binary/text string. (note: 0 means EOF, "0" will
# give a byte (ascii "0") to the reading program)
my ($name) = @_;
$logger->debug("FuseUI rmdir called on $name");
my $obj = get_object($name);
return -ENOENT() unless defined $obj;
my $type = $obj->get_type;
return -ENOENT() if ( $type eq 'leaf' or $type eq 'check_list' );
my $ct = $obj->container_type;
my $elt_name = $obj->element_name;
my $parent = $obj->parent;
if ( $ct eq 'list' or $ct eq 'hash' ) {
my $idx = $obj->index_value;
$logger->debug("FuseUI rmdir actually deletes $idx");
$parent->fetch_element($elt_name)->delete($idx);
}
# ignore deletion request for other "non deletable" elements
return 0;
}
sub unlink {
my ($name) = @_;
$logger->debug("FuseUI unlink called on $name");
my $obj = get_object($name);
my $type = $obj->get_type;
return -ENOENT() unless defined $obj;
return -EISDIR() unless ( $type eq 'leaf' or $type eq 'check_list' );
my $ct = $obj->container_type;
my $elt_name = $obj->element_name;
my $parent = $obj->parent;
if ( $ct eq 'list' or $ct eq 'hash' ) {
my $idx = $obj->index_value;
$logger->debug("FuseUI unlink actually deletes $idx");
$parent->fetch_element($elt_name)->delete($name);
}
# ignore deletion request for other "non deletable" elements
return 0;
}
sub statfs { return 255, 1, 1, 1, 1, 2 }
my @methods = map { ( $_ => __PACKAGE__ . "::$_" ) }
qw/getattr getdir open read write statfs truncate unlink mkdir rmdir/;
# FIXME: flush release
# maybe also: readlink mknod symlink rename link chmod chown utime
sub run_loop {
my ( $self, %args ) = @_;
my $debug = $args{debug} || 0;
Fuse::main(
mountpoint => $self->mountpoint,
@methods,
debug => $debug || 0,
threaded => 0,
);
}
1;
# ABSTRACT: Fuse virtual file interface for Config::Model
__END__
=pod
=encoding UTF-8
=head1 NAME
Config::Model::FuseUI - Fuse virtual file interface for Config::Model
=head1 VERSION
version 2.094
=head1 SYNOPSIS
# command line
mkdir mydir
cme fusefs popcon -fuse-dir mydir
ll mydir
fusermount -u mydir
# programmatic
use Config::Model ;
use Config::Model::FuseUI ;
my $model = Config::Model -> new;
my $root = $model -> instance (root_class_name => "PopCon") -> config_root ;
my $ui = Config::Model::FuseUI->new( root => $root, mountpoint => "mydir" );
$ui -> run_loop ; # blocking call
# explore mydir in another terminal then umount mydir directory
=head1 DESCRIPTION
This module provides a virtual file system interface for you configuration data. Each possible
parameter of your configuration file is mapped to a file.
=head1 Example
$ cme fusefs popcon -fuse-dir fused
Mounting config on fused in background.
Use command 'fusermount -u fused' to unmount
$ ll fused
total 4
-rw-r--r-- 1 domi domi 1 Dec 8 19:27 DAY
-rw-r--r-- 1 domi domi 0 Dec 8 19:27 HTTP_PROXY
-rw-r--r-- 1 domi domi 0 Dec 8 19:27 MAILFROM
-rw-r--r-- 1 domi domi 0 Dec 8 19:27 MAILTO
-rw-r--r-- 1 domi domi 32 Dec 8 19:27 MY_HOSTID
-rw-r--r-- 1 domi domi 3 Dec 8 19:27 PARTICIPATE
-rw-r--r-- 1 domi domi 0 Dec 8 19:27 SUBMITURLS
-rw-r--r-- 1 domi domi 3 Dec 8 19:27 USEHTTP
$ fusermount -u fuse_dir
=head1 BUGS
=over
=item *
For some configuration, mapping each parameter to a file may lead to a high number of files.
=item *
The content of a file is when writing a wrong value. I.e. the files is
empty and the old value is lost.
=back
=head1 constructor
=head1 new (...)
parameters are:
=over
=item model
Config::Model object
=item root
Root of the configuration tree (C<Config::Model::Node> object )
=item mountpoint
=back
=head1 Methods
=head2 run_loop( fork_in_loop => 1|0, debug => 1|0)
Mount the file system either in the current process or fork a new process before mounting the file system.
In the former case, the call is blocking. In the latter case, the call returns after forking a process that
performs the mount. Debug parameter is passed to Fuse system to get traces from Fuse.
=head2 fuse_mount
Mount the fuse file system. This method blocks until the file system is
unmounted (with C<fusermount -u mount_point> command)
=head1 SEE ALSO
L<Fuse>, L<Config::Model>, L<cme>
=head1 AUTHOR
Dominique Dumont
=head1 COPYRIGHT AND LICENSE
This software is Copyright (c) 2005-2016 by Dominique Dumont.
This is free software, licensed under:
The GNU Lesser General Public License, Version 2.1, February 1999
=cut