--- trunk/DBI.pm 2004/08/29 20:12:37 13 +++ trunk/DBI.pm 2004/10/08 22:55:36 26 @@ -10,11 +10,10 @@ use Fuse; use DBI; use Carp; -use Proc::Simple; use Data::Dumper; -our $VERSION = '0.01'; +our $VERSION = '0.03'; =head1 NAME @@ -25,11 +24,11 @@ use Fuse::DBI; Fuse::DBI->mount( ... ); -See L below for examples how to set parametars. +See C below for examples how to set parametars. =head1 DESCRIPTION -This module will use L module, part of C +This module will use C module, part of C available at L to mount your database as file system. @@ -48,7 +47,7 @@ Mount your database as filesystem. my $mnt = Fuse::DBI->mount({ - filenames => 'select name from filenamefilenames, + filenames => 'select name from files_table as filenames', read => 'sql read', update => 'sql update', dsn => 'DBI:Pg:dbname=webgui', @@ -63,6 +62,12 @@ my $ctime_start; 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 $class = shift; @@ -77,47 +82,64 @@ carp "mount needs 'mount' as mountpoint" unless ($arg->{'mount'}); # save (some) arguments in self - $self->{$_} = $arg->{$_} foreach (qw(mount)); + foreach (qw(mount invalidate)) { + $self->{$_} = $arg->{$_}; + } foreach (qw(filenames read update)) { 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->{'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->{'sth'} = $sth; + + $self->{'read_filenames'} = sub { $self->read_filenames }; + $self->read_filenames; - $self->{'proc'} = Proc::Simple->new(); - $self->{'proc'}->kill_on_destroy(1); + $self->{'mounted'} = 1; - $self->{'proc'}->start( sub { - Fuse::main( - mountpoint=>$arg->{'mount'}, - getattr=>\&e_getattr, - getdir=>\&e_getdir, - open=>\&e_open, - statfs=>\&e_statfs, - read=>\&e_read, - write=>\&e_write, - utime=>\&e_utime, - truncate=>\&e_truncate, - debug=>0, - ); - } ); + $fuse_self = \$self; + + Fuse::main( + mountpoint=>$arg->{'mount'}, + getattr=>\&e_getattr, + getdir=>\&e_getdir, + open=>\&e_open, + statfs=>\&e_statfs, + read=>\&e_read, + write=>\&e_write, + utime=>\&e_utime, + truncate=>\&e_truncate, + unlink=>\&e_unlink, + rmdir=>\&e_unlink, + debug=>0, + ); + + $self->{'mounted'} = 0; - confess "Fuse::main failed" if (! $self->{'proc'}->poll); + exit(0) if ($arg->{'fork'}); + + return 1; - $self ? return $self : return undef; }; =head2 umount @@ -134,25 +156,54 @@ sub umount { my $self = shift; - confess "no process running?" unless ($self->{'proc'}); + if ($self->{'mounted'}) { + system "fusermount -u ".$self->{'mount'} || croak "umount error: $!"; + } + + return 1; +} + +$SIG{'INT'} = sub { + print STDERR "umount called by SIG INT\n"; + umount; +}; + +sub DESTROY { + my $self = shift; + return if (! $self->{'mounted'}); + print STDERR "umount called by DESTROY\n"; + $self->umount; +} + +=head2 fuse_module_loaded - system "fusermount -u ".$self->{'mount'} || croak "umount error: $!"; +Checks if C module is loaded in kernel. - if ($self->{'proc'}->poll) { - $self->{'proc'}->kill; - return 1 if (! $self->{'proc'}->poll); - } else { + die "no fuse module loaded in kernel" + unless (Fuse::DBI::fuse_module_loaded); + +This function in called by L, 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; + my $sth = $self->{'sth'} || die "no sth argument"; + # create empty filesystem (%files) = ( '.' => { @@ -252,6 +303,18 @@ return (keys %out),0; } +sub read_content { + my ($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; + $files{$file}{ctime} = time(); + 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 $file = filename_fixup(shift); @@ -260,11 +323,8 @@ return -ENOENT() unless exists($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; } @@ -285,7 +345,7 @@ 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); } @@ -298,7 +358,7 @@ delete $files{$f}{cont}; } print "begin new transaction\n"; - $dbh->begin_work || die $dbh->errstr; + #$dbh->begin_work || die $dbh->errstr; } @@ -307,7 +367,12 @@ $files{$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; @@ -318,29 +383,35 @@ 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 $off length\n"; + print "write '$file' [$len bytes] offset $off length ",length($buffer),"\n"; - $files{$file}{cont} = - substr($files{$file}{cont},0,$off) . - $buf_len . - substr($files{$file}{cont},$off+length($buf_len)); + $files{$file}{cont} = ""; + + $files{$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); } } @@ -348,7 +419,10 @@ 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 }; @@ -367,6 +441,22 @@ sub e_statfs { return 255, 1, 1, 1, 1, 2 } +sub e_unlink { + my $file = filename_fixup(shift); + + if (exists( $dirs{$file} )) { + print "unlink '$file' will re-read template names\n"; + print Dumper($fuse_self); + $$fuse_self->{'read_filenames'}->(); + return 0; + } elsif (exists( $files{$file} )) { + print "unlink '$file' will invalidate cache\n"; + read_content($file,$files{$file}{id}); + return 0; + } + + return -ENOENT(); +} 1; __END__