use POSIX qw(ENOENT EISDIR EINVAL ENOSYS O_RDWR);
use Fuse;
use DBI;
+use Carp;
+use Data::Dumper;
-our $VERSION = '0.01';
+
+our $VERSION = '0.03';
=head1 NAME
=head1 SYNOPSIS
use Fuse::DBI;
- Fuse::DBI->run( ... );
+ Fuse::DBI->mount( ... );
-See L<run> below for examples how to set parametars.
+See C<run> below for examples how to set parametars.
=head1 DESCRIPTION
-This module will use L<Fuse> module, part of C<FUSE (Filesystem in USErspace)>
+This module will use C<Fuse> module, part of C<FUSE (Filesystem in USErspace)>
available at L<http://sourceforge.net/projects/avf> to mount
your database as file system.
=cut
-=head2 run
+=head2 mount
Mount your database as filesystem.
- Fuse::DBI->run({
- filenames => 'select name from filenamefilenames,
+ my $mnt = Fuse::DBI->mount({
+ filenames => 'select name from files_table as filenames',
read => 'sql read',
update => 'sql update',
dsn => 'DBI:Pg:dbname=webgui',
my $sth;
my $ctime_start;
-sub run {
- my $self = shift
+sub read_filenames;
+sub fuse_module_loaded;
+
+# evil, evil way to solve this. It makes this module non-reentrant. But, since
+# fuse calls another copy of this script for each mount anyway, this shouldn't
+# be a problem.
+my $fuse_self;
+
+sub mount {
+ my $class = shift;
+ my $self = {};
+ bless($self, $class);
- my $arg = {@_};
+ my $arg = shift;
- carp "run needs 'dsn' to connect to (e.g. dsn => 'DBI:Pg:dbname=test')" unless ($arg->{'dsn'});
- carp "run needs 'mount' as mountpoint" unless ($arg->{'mount'});
+ print Dumper($arg);
+
+ carp "mount needs 'dsn' to connect to (e.g. dsn => 'DBI:Pg:dbname=test')" unless ($arg->{'dsn'});
+ carp "mount needs 'mount' as mountpoint" unless ($arg->{'mount'});
+
+ # save (some) arguments in self
+ foreach (qw(mount invalidate)) {
+ $self->{$_} = $arg->{$_};
+ $fuse_self->{$_} = $arg->{$_};
+ }
foreach (qw(filenames read update)) {
- carp "run needs '$_' SQL" unless ($arg->{$_});
+ carp "mount needs '$_' SQL" unless ($arg->{$_});
}
- $dbh = DBI->connect($arg->{'dsn'},$arg->{'user'},$arg->{'password'}, { AutoCommit => 0 }) || die $DBI::errstr;
+ $ctime_start = time();
- print "start transaction\n";
- #$dbh->begin_work || die $dbh->errstr;
+ my $pid;
+ if ($arg->{'fork'}) {
+ $pid = fork();
+ die "fork() failed: $!" unless defined $pid;
+ # child will return to caller
+ if ($pid) {
+ return $self;
+ }
+ }
+
+ $dbh = DBI->connect($arg->{'dsn'},$arg->{'user'},$arg->{'password'}, {AutoCommit => 0, RaiseError => 1}) || die $DBI::errstr;
$sth->{filenames} = $dbh->prepare($arg->{'filenames'}) || die $dbh->errstr();
$sth->{'read'} = $dbh->prepare($arg->{'read'}) || die $dbh->errstr();
$sth->{'update'} = $dbh->prepare($arg->{'update'}) || die $dbh->errstr();
- $ctime_start = time();
-
- read_filenames;
+ $self->read_filenames;
Fuse::main(
mountpoint=>$arg->{'mount'},
write=>\&e_write,
utime=>\&e_utime,
truncate=>\&e_truncate,
+ unlink=>\&e_unlink,
debug=>0,
);
+
+ exit(0) if ($arg->{'fork'});
+
+ return 1;
+
};
+=head2 umount
+
+Unmount your database as filesystem.
+
+ $mnt->umount;
+
+This will also kill background process which is translating
+database to filesystem.
+
+=cut
+
+sub umount {
+ my $self = shift;
+
+ system "fusermount -u ".$self->{'mount'} || croak "umount error: $!";
+
+ return 1;
+}
+
+#$SIG{'INT'} = sub {
+# print STDERR "umount called by SIG INT\n";
+# umount;
+#};
+
+sub DESTROY {
+ my $self = shift;
+ print STDERR "umount called by DESTROY\n";
+ $self->umount;
+}
+
+=head2 fuse_module_loaded
+
+Checks if C<fuse> module is loaded in kernel.
+
+ die "no fuse module loaded in kernel"
+ unless (Fuse::DBI::fuse_module_loaded);
+
+This function in called by L<mount>, but might be useful alone also.
+
+=cut
+
+sub fuse_module_loaded {
+ my $lsmod = `lsmod`;
+ die "can't start lsmod: $!" unless ($lsmod);
+ if ($lsmod =~ m/fuse/s) {
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
my %files;
my %dirs;
sub read_filenames {
+ my $self = shift;
+
# create empty filesystem
(%files) = (
'.' => {
# return as many text filenames as you like, followed by the retval.
print((scalar keys %files)." files total\n");
my %out;
- foreach (keys %files) {
- my $f = $_;
- $f =~ s/^\E$dirname\Q//;
- $f =~ s/^\///;
+ foreach my $f (sort keys %files) {
if ($dirname) {
- $out{$f}++ if (/^\E$dirname\Q/ && $f =~ /^[^\/]+$/);
+ if ($f =~ s/^\E$dirname\Q\///) {
+ $out{$f}++ if ($f =~ /^[^\/]+$/);
+ }
} else {
$out{$f}++ if ($f =~ /^[^\/]+$/);
}
$out{'no files? bug?'}++;
}
print scalar keys %out," files in dir '$dirname'\n";
+ print "## ",join(" ",keys %out),"\n";
return (keys %out),0;
}
+sub read_content {
+ my ($file,$id) = @_;
+
+ die "read_content needs file and id" unless ($file && $id);
+
+ $sth->{'read'}->execute($id) || die $sth->{'read'}->errstr;
+ $files{$file}{cont} = $sth->{'read'}->fetchrow_array;
+ print "file '$file' content [",length($files{$file}{cont})," bytes] read in cache\n";
+}
+
+
sub e_open {
# VFS sanity check; it keeps all the necessary state, not much to do here.
my $file = filename_fixup(shift);
return -ENOENT() unless exists($files{$file});
return -EISDIR() unless exists($files{$file}{id});
- if (!exists($files{$file}{cont})) {
- $sth->{'read'}->execute($files{$file}{id}) || die $sth->{'read'}->errstr;
- $files{$file}{cont} = $sth->{'read'}->fetchrow_array;
- print "file '$file' content read in cache\n";
- }
+ read_content($file,$files{$file}{id}) unless exists($files{$file}{cont});
+
print "open '$file' ",length($files{$file}{cont})," bytes\n";
return 0;
}
return -EINVAL() if ($off > $len);
return 0 if ($off == $len);
- $buf_len = $buf_len-$off if ($off+$buf_len > $len);
+ $buf_len = $len-$off if ($len - $off < $buf_len);
return substr($files{$file}{cont},$off,$buf_len);
}
delete $files{$f}{cont};
}
print "begin new transaction\n";
- $dbh->begin_work || die $dbh->errstr;
+ #$dbh->begin_work || die $dbh->errstr;
}
$files{$file}{ctime} = time();
- if (!$sth->{'update'}->execute($files{$file}{cont},$files{$file}{id})) {
+ my ($cont,$id) = (
+ $files{$file}{cont},
+ $files{$file}{id}
+ );
+
+ if (!$sth->{'update'}->execute($cont,$id)) {
print "update problem: ",$sth->{'update'}->errstr;
clear_cont;
return 0;
return 0;
}
print "updated '$file' [",$files{$file}{id},"]\n";
+
+ $fuse_self->{'invalidate'}->() if (ref $fuse_self->{'invalidate'});
}
return 1;
}
sub e_write {
my $file = filename_fixup(shift);
- my ($buf_len,$off) = @_;
+ my ($buffer,$off) = @_;
return -ENOENT() unless exists($files{$file});
- my $len = length($files{$file}{cont});
+ my $cont = $files{$file}{cont};
+ my $len = length($cont);
+
+ print "write '$file' [$len bytes] offset $off length ",length($buffer),"\n";
- print "write '$file' [$len bytes] offset $off length\n";
+ $files{$file}{cont} = "";
- $files{$file}{cont} =
- substr($files{$file}{cont},0,$off) .
- $buf_len .
- substr($files{$file}{cont},$off+length($buf_len));
+ $files{$file}{cont} .= substr($cont,0,$off) if ($off > 0);
+ $files{$file}{cont} .= $buffer;
+ $files{$file}{cont} .= substr($cont,$off+length($buffer),$len-$off-length($buffer)) if ($off+length($buffer) < $len);
+
+ $files{$file}{size} = length($files{$file}{cont});
if (! update_db($file)) {
return -ENOSYS();
} else {
- return length($buf_len);
+ return length($buffer);
}
}
my $file = filename_fixup(shift);
my $size = shift;
+ print "truncate to $size\n";
+
$files{$file}{cont} = substr($files{$file}{cont},0,$size);
+ $files{$file}{size} = $size;
return 0
};
sub e_statfs { return 255, 1, 1, 1, 1, 2 }
+sub e_unlink {
+ my $file = filename_fixup(shift);
+
+ return -ENOENT() unless exists($files{$file});
+
+ print "unlink '$file' will invalidate cache\n";
+
+ read_content($file,$files{$file}{id});
+
+ return 0;
+}
1;
__END__
projects / Fuse-DBI / blobdiff