a lot of changes (0.03 API):

- added unlink (rm) method to invalidate in-memory cache
- added fuse_module_loaded method to check if fuse module is loaded
- fixed short read of last block
- removed Proc::Simple usage and replaced with simplier forking mechanism

This is first working version, but it's not binary-safe yet. NULL bytes
are still problem.

git-svn-id: svn://svn.rot13.org/fuse_dbi/trunk@21 17f4e80c-d0e0-0310-8903-bfc3ae804c12

diff --git a/DBI.pm b/DBI.pm
index 96b3ea3..8caecd3 100755 (executable)
--- a/DBI.pm
+++ b/DBI.pm
@@ -10,11 +10,10 @@ use POSIX qw(ENOENT EISDIR EINVAL ENOSYS O_RDWR);
 use Fuse;
 use DBI;
 use Carp;
 use Fuse;
 use DBI;
 use Carp;

-use Proc::Simple;

 use Data::Dumper;
 
 
 use Data::Dumper;
 
 

-our $VERSION = '0.02';
+our $VERSION = '0.03';

 
 =head1 NAME
 
 
 =head1 NAME
 


@@ -48,7 +47,7 @@ It's actually opposite of Oracle's intention to put everything into database.
 Mount your database as filesystem.
 
   my $mnt = Fuse::DBI->mount({
 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',
        read => 'sql read',
        update => 'sql update',
        dsn => 'DBI:Pg:dbname=webgui',


@@ -63,6 +62,7 @@ my $sth;
 my $ctime_start;
 
 sub read_filenames;
 my $ctime_start;
 
 sub read_filenames;

+sub fuse_module_loaded;

 
 sub mount {
        my $class = shift;
 
 sub mount {
        my $class = shift;


@@ -83,41 +83,44 @@ sub mount {
                carp "mount 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 $dbh->errstr;
+       if ($arg->{'fork'}) {
+               my $pid = fork();
+               die "fork() failed: $!" unless defined $pid;
+               # child will return to caller
+               if ($pid) {
+                       $self ? return $self : return undef;
+               }
+       }
+
+       $dbh = DBI->connect($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();
 
 
        $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();
+       $self->read_filenames;
+
+       my $mount = Fuse::main(
+               mountpoint=>$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,
+               debug=>0,
+       );

 
 

-       read_filenames;
-
-       $self->{'proc'} = Proc::Simple->new();
-       $self->{'proc'}->kill_on_destroy(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,
-               );
-       } );
-
-       confess "Fuse::main failed" if (! $self->{'proc'}->poll);
-
-       $self ? return $self : return undef;
+       if (! $mount) {
+               warn "mount on ",$arg->{'mount'}," failed!\n";
+               return undef;
+       }

 };
 
 =head2 umount
 };
 
 =head2 umount


@@ -134,19 +137,32 @@ database to filesystem.
 sub umount {
        my $self = shift;
 
 sub umount {
        my $self = shift;
 

-       confess "no process running?" unless ($self->{'proc'});
-

        system "fusermount -u ".$self->{'mount'} || croak "umount error: $!";
 
        system "fusermount -u ".$self->{'mount'} || croak "umount error: $!";
 

-       if ($self->{'proc'}->poll) {
-               $self->{'proc'}->kill;
-               return 1 if (! $self->{'proc'}->poll);
-       } else {
+       return 1;
+}
+
+=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;
                return 1;

+       } else {
+               return 0;

        }
 }
 
        }
 }
 

-

 my %files;
 my %dirs;
 
 my %files;
 my %dirs;
 


@@ -252,6 +268,17 @@ sub e_getdir {
        return (keys %out),0;
 }
 
        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);
 sub e_open {
        # VFS sanity check; it keeps all the necessary state, not much to do here.
        my $file = filename_fixup(shift);


@@ -260,11 +287,8 @@ sub e_open {
        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});
 

-       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{$file}{cont})," bytes\n";
        return 0;
 }
        print "open '$file' ",length($files{$file}{cont})," bytes\n";
        return 0;
 }


@@ -285,7 +309,7 @@ sub e_read {
        return -EINVAL() if ($off > $len);
        return 0 if ($off == $len);
 
        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);
 }
 
        return substr($files{$file}{cont},$off,$buf_len);
 }


@@ -298,7 +322,7 @@ sub clear_cont {
                delete $files{$f}{cont};
        }
        print "begin new transaction\n";
                delete $files{$f}{cont};
        }
        print "begin new transaction\n";

-       $dbh->begin_work || die $dbh->errstr;
+       #$dbh->begin_work || die $dbh->errstr;

 }
 
 
 }
 
 


@@ -307,7 +331,12 @@ sub update_db {
 
        $files{$file}{ctime} = time();
 
 
        $files{$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: ",$sth->{'update'}->errstr;
                clear_cont;
                return 0;
                print "update problem: ",$sth->{'update'}->errstr;
                clear_cont;
                return 0;


@@ -337,7 +366,7 @@ sub e_write {
 
        $files{$file}{cont} .= substr($cont,0,$off) if ($off > 0);
        $files{$file}{cont} .= $buffer;
 
        $files{$file}{cont} .= substr($cont,0,$off) if ($off > 0);
        $files{$file}{cont} .= $buffer;

-       $files{$file}{cont} .= substr($cont,-($off+length($buffer))) if ($off+length($buffer) > $len);
+       $files{$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});
 


@@ -374,6 +403,17 @@ sub e_utime {
 
 sub e_statfs { return 255, 1, 1, 1, 1, 2 }
 
 
 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__
 
 1;
 __END__