use svk, cpan target
[Fuse-DBI] / DBI.pm
diff --git a/DBI.pm b/DBI.pm
index c8572ce..425822d 100755 (executable)
--- a/DBI.pm
+++ b/DBI.pm
@@ -12,8 +12,10 @@ use DBI;
 use Carp;
 use Data::Dumper;
 
+our $VERSION = '0.09_1';
 
-our $VERSION = '0.06';
+# block size for this filesystem
+use constant BLOCK => 1024;
 
 =head1 NAME
 
@@ -109,6 +111,25 @@ running. Implementation is experimental.
 
 =back
 
+There is also alternative way which can generate C<read> and C<update>
+queries on the fly:
+
+  my $mnt = Fuse::DBI->mount({
+       'filenames' => 'select id,filename,size,writable from files',
+       'read' => sub {
+               my ($path,$file) = @_;
+               return( 'select content from files where id = ?', $file->{row}->{id} );
+       },
+       'update' => sub {
+               my ($path,$file) = @_;
+               return( 'update files set content = ? where id = ?', $file->{row}->{id} );
+       },
+       'dsn' => 'DBI:Pg:dbname=test_db',
+       'user' => 'database_user',
+       'password' => 'database_password',
+       'invalidate' => sub { ... },
+  });
+
 =cut
 
 my $dbh;
@@ -123,6 +144,8 @@ sub fuse_module_loaded;
 # be a problem.
 my $fuse_self;
 
+my $debug = 0;
+
 sub mount {
        my $class = shift;
        my $self = {};
@@ -132,6 +155,11 @@ sub mount {
 
        print Dumper($arg);
 
+       unless ($self->fuse_module_loaded) {
+               print STDERR "no fuse module loaded. Trying sudo modprobe fuse!\n";
+               system "sudo modprobe fuse" || die "can't modprobe fuse using sudo!\n";
+       }
+
        carp "mount needs 'dsn' to connect to (e.g. dsn => 'DBI:Pg:dbname=test')" unless ($arg->{'dsn'});
        carp "mount needs 'mount' as mountpoint" unless ($arg->{'mount'});
 
@@ -152,7 +180,16 @@ sub mount {
                die "fork() failed: $!" unless defined $pid;
                # child will return to caller
                if ($pid) {
-                       return $self;
+                       my $counter = 4;
+                       while ($counter && ! $self->is_mounted) {
+                               select(undef, undef, undef, 0.5);
+                               $counter--;
+                       }
+                       if ($self->is_mounted) {
+                               return $self;
+                       } else {
+                               return undef;
+                       }
                }
        }
 
@@ -160,16 +197,24 @@ sub mount {
 
        $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();
-
-
        $self->{'sth'} = $sth;
+       $self->{'dbh'} = $dbh;
 
        $self->{'read_filenames'} = sub { $self->read_filenames };
        $self->read_filenames;
 
-       $fuse_self = \$self;
+       foreach my $op (qw/read update/) {
+               if (ref($arg->{ $op }) ne 'CODE') {
+                       $self->{ $op . '_ref' } = sub {
+                               my $row = shift;
+                               return ($arg->{ $op }, $row->{'id'});
+                       }
+               } else {
+                       $self->{ $op . '_ref' } = $arg->{ $op };
+               }
+       }
+
+       $fuse_self = $self;
 
        Fuse::main(
                mountpoint=>$arg->{'mount'},
@@ -183,7 +228,7 @@ sub mount {
                truncate=>\&e_truncate,
                unlink=>\&e_unlink,
                rmdir=>\&e_unlink,
-               debug=>0,
+               debug=>$debug,
        );
        
        exit(0) if ($arg->{'fork'});
@@ -192,6 +237,32 @@ sub mount {
 
 };
 
+=head2 is_mounted
+
+Check if fuse filesystem is mounted
+
+  if ($mnt->is_mounted) { ... }
+
+=cut
+
+sub is_mounted {
+       my $self = shift;
+
+       my $mounted = 0;
+       my $mount = $self->{'mount'} || confess "can't find mount point!";
+       if (open(MTAB, "/etc/mtab")) {
+               while(<MTAB>) {
+                       $mounted = 1 if (/ $mount fuse /i);
+               }
+               close(MTAB);
+       } else {
+               warn "can't open /etc/mtab: $!";
+       }
+
+       return $mounted;
+}
+
+
 =head2 umount
 
 Unmount your database as filesystem.
@@ -206,35 +277,27 @@ database to filesystem.
 sub umount {
        my $self = shift;
 
-       if ($self->{'mount'}) {
-               if (open(MTAB, "/etc/mtab")) {
-                       my $mounted = 0;
-                       my $mount = $self->{'mount'};
-                       while(<MTAB>) {
-                               $mounted = 1 if (/ $mount fuse /i);
-                       }
-                       close(MTAB);
-               
-                       if ($mounted) {
-                               system "fusermount -u ".$self->{'mount'}." 2>&1 >/dev/null" || return 0;
-                               return 1;
-                       }
-
-               } else {
-                       warn "can't open /etc/mtab: $!";
+       if ($self->{'mount'} && $self->is_mounted) {
+               system "( fusermount -u ".$self->{'mount'}." 2>&1 ) >/dev/null";
+               sleep 1;
+               if ($self->is_mounted) {
+                       system "sudo umount ".$self->{'mount'} ||
                        return 0;
                }
+               return 1;
        }
+
+       return 0;
 }
 
 $SIG{'INT'} = sub {
-       if ($fuse_self && $$fuse_self->umount) {
+       if ($fuse_self && $fuse_self->can('umount')) {
                print STDERR "umount called by SIG INT\n";
        }
 };
 
 $SIG{'QUIT'} = sub {
-       if ($fuse_self && $$fuse_self->umount) {
+       if ($fuse_self && $fuse_self->can('umount')) {
                print STDERR "umount called by SIG QUIT\n";
        }
 };
@@ -267,8 +330,7 @@ sub fuse_module_loaded {
        }
 }
 
-my %files;
-my %dirs;
+my $files;
 
 sub read_filenames {
        my $self = shift;
@@ -276,7 +338,7 @@ sub read_filenames {
        my $sth = $self->{'sth'} || die "no sth argument";
 
        # create empty filesystem
-       (%files) = (
+       $files = {
                '.' => {
                        type => 0040,
                        mode => 0755,
@@ -290,33 +352,35 @@ sub read_filenames {
        #               type => 0100,
        #               ctime => time()-2000
        #       },
-       );
+       };
 
        # fetch new filename list from database
        $sth->{'filenames'}->execute() || die $sth->{'filenames'}->errstr();
 
        # read them in with sesible defaults
        while (my $row = $sth->{'filenames'}->fetchrow_hashref() ) {
-               $files{$row->{'filename'}} = {
+               $row->{'filename'} ||= 'NULL-'.$row->{'id'};
+               $files->{$row->{'filename'}} = {
                        size => $row->{'size'},
                        mode => $row->{'writable'} ? 0644 : 0444,
-                       id => $row->{'id'} || 99,
+                       id => $row->{'id'} || undef,
+                       row => $row,
                };
 
+
                my $d;
                foreach (split(m!/!, $row->{'filename'})) {
                        # first, entry is assumed to be file
                        if ($d) {
-                               $files{$d} = {
-                                               size => $dirs{$d}++,
+                               $files->{$d} = {
                                                mode => 0755,
                                                type => 0040
                                };
-                               $files{$d.'/.'} = {
+                               $files->{$d.'/.'} = {
                                                mode => 0755,
                                                type => 0040
                                };
-                               $files{$d.'/..'} = {
+                               $files->{$d.'/..'} = {
                                                mode => 0755,
                                                type => 0040
                                };
@@ -326,7 +390,7 @@ sub read_filenames {
                }
        }
 
-       print "found ",scalar(keys %files)-scalar(keys %dirs)," files, ",scalar(keys %dirs), " dirs\n";
+       print "found ",scalar(keys %{$files})," files\n";
 }
 
 
@@ -341,17 +405,17 @@ sub e_getattr {
        my ($file) = filename_fixup(shift);
        $file =~ s,^/,,;
        $file = '.' unless length($file);
-       return -ENOENT() unless exists($files{$file});
-       my ($size) = $files{$file}{size} || 1;
-       my ($dev, $ino, $rdev, $blocks, $gid, $uid, $nlink, $blksize) = (0,0,0,1,0,0,1,1024);
+       return -ENOENT() unless exists($files->{$file});
+       my ($size) = $files->{$file}->{size} || 0;
+       my ($dev, $ino, $rdev, $blocks, $gid, $uid, $nlink, $blksize) = (0,0,0,int(($size+BLOCK-1)/BLOCK),0,0,1,BLOCK);
        my ($atime, $ctime, $mtime);
-       $atime = $ctime = $mtime = $files{$file}{ctime} || $ctime_start;
+       $atime = $ctime = $mtime = $files->{$file}->{ctime} || $ctime_start;
 
-       my ($modes) = (($files{$file}{type} || 0100)<<9) + $files{$file}{mode};
+       my ($modes) = (($files->{$file}->{type} || 0100)<<9) + $files->{$file}->{mode};
 
        # 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,$blocks)),"\n");
+       #print "getattr($file) ",join(",",($dev,$ino,$modes,$nlink,$uid,$gid,$rdev,$size,$atime,$mtime,$ctime,$blksize,$blocks)),"\n";
        return ($dev,$ino,$modes,$nlink,$uid,$gid,$rdev,$size,$atime,$mtime,$ctime,$blksize,$blocks);
 }
 
@@ -359,9 +423,9 @@ sub e_getdir {
        my ($dirname) = shift;
        $dirname =~ s!^/!!;
        # return as many text filenames as you like, followed by the retval.
-       print((scalar keys %files)." files total\n");
+       print((scalar keys %{$files})." files total\n");
        my %out;
-       foreach my $f (sort keys %files) {
+       foreach my $f (sort keys %{$files}) {
                if ($dirname) {
                        if ($f =~ s/^\Q$dirname\E\///) {
                                $out{$f}++ if ($f =~ /^[^\/]+$/);
@@ -379,15 +443,21 @@ sub e_getdir {
 }
 
 sub read_content {
-       my ($file,$id) = @_;
+       my $file = shift || die "need file";
+
+       warn "# read_content($file)\n" if ($debug);
+
+       my @args = $fuse_self->{'read_ref'}->($files->{$file});
+       my $sql = shift @args || die "need SQL for $file";
 
-       die "read_content needs file and id" unless ($file && $id);
+       $fuse_self->{'read_sth'}->{$sql} ||= $fuse_self->{dbh}->prepare($sql) || die $dbh->errstr();
+       my $sth = $fuse_self->{'read_sth'}->{$sql} || die;
 
-       $sth->{'read'}->execute($id) || die $sth->{'read'}->errstr;
-       $files{$file}{cont} = $sth->{'read'}->fetchrow_array;
+       $sth->execute(@args) || die $sth->errstr;
+       $files->{$file}->{cont} = $sth->fetchrow_array;
        # I should modify ctime only if content in database changed
-       #$files{$file}{ctime} = time() unless ($files{$file}{ctime});
-       print "file '$file' content [",length($files{$file}{cont})," bytes] read in cache\n";
+       #$files->{$file}->{ctime} = time() unless ($files->{$file}->{ctime});
+       print "file '$file' content [",length($files->{$file}->{cont})," bytes] read in cache\n";
 }
 
 
@@ -396,12 +466,13 @@ sub e_open {
        my $file = filename_fixup(shift);
        my $flags = shift;
 
-       return -ENOENT() unless exists($files{$file});
-       return -EISDIR() unless exists($files{$file}{id});
+       return -ENOENT() unless exists($files->{$file});
+       return -EISDIR() unless exists($files->{$file}->{id});
 
-       read_content($file,$files{$file}{id}) unless exists($files{$file}{cont});
+       read_content($file,$files->{$file}->{id}) unless exists($files->{$file}->{cont});
 
-       print "open '$file' ",length($files{$file}{cont})," bytes\n";
+       $files->{$file}->{cont} ||= '';
+       print "open '$file' ",length($files->{$file}->{cont})," bytes\n";
        return 0;
 }
 
@@ -412,9 +483,9 @@ sub e_read {
        my ($file) = filename_fixup(shift);
        my ($buf_len,$off) = @_;
 
-       return -ENOENT() unless exists($files{$file});
+       return -ENOENT() unless exists($files->{$file});
 
-       my $len = length($files{$file}{cont});
+       my $len = length($files->{$file}->{cont});
 
        print "read '$file' [$len bytes] offset $off length $buf_len\n";
 
@@ -423,16 +494,16 @@ sub e_read {
 
        $buf_len = $len-$off if ($len - $off < $buf_len);
 
-       return substr($files{$file}{cont},$off,$buf_len);
+       return substr($files->{$file}->{cont},$off,$buf_len);
 }
 
 sub clear_cont {
        print "transaction rollback\n";
        $dbh->rollback || die $dbh->errstr;
        print "invalidate all cached content\n";
-       foreach my $f (keys %files) {
-               delete $files{$f}{cont};
-               delete $files{$f}{ctime};
+       foreach my $f (keys %{$files}) {
+               delete $files->{$f}->{cont};
+               delete $files->{$f}->{ctime};
        }
        print "begin new transaction\n";
        #$dbh->begin_work || die $dbh->errstr;
@@ -440,28 +511,40 @@ sub clear_cont {
 
 
 sub update_db {
-       my $file = shift || die;
+       my $file = shift || die "need file";
 
-       $files{$file}{ctime} = time();
+       $files->{$file}->{ctime} = time();
 
        my ($cont,$id) = (
-               $files{$file}{cont},
-               $files{$file}{id}
+               $files->{$file}->{cont},
+               $files->{$file}->{id}
        );
 
-       if (!$sth->{'update'}->execute($cont,$id)) {
-               print "update problem: ",$sth->{'update'}->errstr;
+       my @args = $fuse_self->{'update_ref'}->($files->{$file});
+
+       my $sql = shift @args || die "need SQL for $file";
+
+       unshift @args, $files->{$file}->{cont} if ($#args == 0);
+
+       warn "## SQL: $sql\n# files->{$file} = ", Dumper($files->{$file}), $/ if ($debug);
+
+       my $sth = $fuse_self->{'update_sth'}->{$sql}
+               ||= $fuse_self->{dbh}->prepare($sql)
+               || die $dbh->errstr();
+
+       if (!$sth->execute(@args)) {
+               print "update problem: ",$sth->errstr;
                clear_cont;
                return 0;
        } else {
                if (! $dbh->commit) {
-                       print "ERROR: commit problem: ",$sth->{'update'}->errstr;
+                       print "ERROR: commit problem: ",$sth->errstr;
                        clear_cont;
                        return 0;
                }
-               print "updated '$file' [",$files{$file}{id},"]\n";
+               print "updated '$file' [",$files->{$file}->{id},"]\n";
 
-               $$fuse_self->{'invalidate'}->() if (ref $$fuse_self->{'invalidate'});
+               $fuse_self->{'invalidate'}->() if ($fuse_self->can('invalidate'));
        }
        return 1;
 }
@@ -470,20 +553,20 @@ sub e_write {
        my $file = filename_fixup(shift);
        my ($buffer,$off) = @_;
 
-       return -ENOENT() unless exists($files{$file});
+       return -ENOENT() unless exists($files->{$file});
 
-       my $cont = $files{$file}{cont};
+       my $cont = $files->{$file}->{cont};
        my $len = length($cont);
 
        print "write '$file' [$len bytes] offset $off length ",length($buffer),"\n";
 
-       $files{$file}{cont} = "";
+       $files->{$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}->{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});
+       $files->{$file}->{size} = length($files->{$file}->{cont});
 
        if (! update_db($file)) {
                return -ENOSYS();
@@ -498,8 +581,8 @@ sub e_truncate {
 
        print "truncate to $size\n";
 
-       $files{$file}{cont} = substr($files{$file}{cont},0,$size);
-       $files{$file}{size} = $size;
+       $files->{$file}->{cont} = substr($files->{$file}->{cont},0,$size);
+       $files->{$file}->{size} = $size;
        return 0
 };
 
@@ -508,27 +591,47 @@ sub e_utime {
        my ($atime,$mtime,$file) = @_;
        $file = filename_fixup($file);
 
-       return -ENOENT() unless exists($files{$file});
+       return -ENOENT() unless exists($files->{$file});
 
        print "utime '$file' $atime $mtime\n";
 
-       $files{$file}{time} = $mtime;
+       $files->{$file}->{time} = $mtime;
        return 0;
 }
 
-sub e_statfs { return 255, 1, 1, 1, 1, 2 }
+sub e_statfs {
+
+       my $size = 0;
+       my $inodes = 0;
+
+       foreach my $f (keys %{$files}) {
+               if ($f !~ /(^|\/)\.\.?$/) {
+                       $size += $files->{$f}->{size} || 0;
+                       $inodes++;
+               }
+               print "$inodes: $f [$size]\n";
+       }
+
+       $size = int(($size+BLOCK-1)/BLOCK);
+
+       my @ret = (255, $inodes, 1, $size, $size-1, BLOCK);
+
+       #print "statfs: ",join(",",@ret),"\n";
+
+       return @ret;
+}
 
 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} )) {
+#      if (exists( $dirs{$file} )) {
+#              print "unlink '$file' will re-read template names\n";
+#              print Dumper($fuse_self);
+#              $fuse_self->{'read_filenames'}->();
+#              return 0;
+       if (exists( $files->{$file} )) {
                print "unlink '$file' will invalidate cache\n";
-               read_content($file,$files{$file}{id});
+               read_content($file,$files->{$file}->{id});
                return 0;
        }