X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2FID3FS%2FPath.pm;h=e54c7e29735c977b953294a2a9ac5f23d304df78;hb=3b83e0afa68f15baa1a1ee0fddae969fa5a637c2;hp=8e7c791f07b113487fb165ebf922c86e88483e76;hpb=87fbf95a66bc4fd0134966a269fbc3ea639b8e34;p=id3fs.git

diff --git a/lib/ID3FS/Path.pm b/lib/ID3FS/Path.pm
index 8e7c791..e54c7e2 100644
--- a/lib/ID3FS/Path.pm
+++ b/lib/ID3FS/Path.pm
@@ -1,21 +1,37 @@
+# id3fs - a FUSE-based filesystem for browsing audio metadata
+# Copyright (C) 2010  Ian Beckwith <ianb@erislabs.net>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 package ID3FS::Path;
 
 use strict;
 use warnings;
-use ID3FS::PathElement::Artist;
-use ID3FS::PathElement::Album;
-use ID3FS::PathElement::Boolean;
-use ID3FS::PathElement::File;
-use ID3FS::PathElement::Tag;
-use ID3FS::PathElement::Tagval;
 use ID3FS::Path::Node;
 
-our ($STATE_INVALID, $STATE_ROOT, $STATE_TAG, $STATE_TAGVAL,
-     $STATE_BOOLEAN, $STATE_ALBUMS, $STATE_TRACKLIST,
-     $STATE_FILE)=(0..7);
+our ($STATE_INVALID, $STATE_ROOT, $STATE_TAG, $STATE_BOOLEAN,
+     $STATE_ALBUMS, $STATE_TRACKLIST, $STATE_FILE, $STATE_ALL)=(0..7);
 
+# operator precedence
 our %priorities=( "OR" => 0, "AND" => 1, "NOT" => 2 );
 
+our $PATH_ALLTRACKS= "TRACKS";
+our $PATH_NOARTIST = "NOARTIST";
+our $PATH_NOALBUM  = "NOALBUM";
+
+our $ENABLE_FILTER = 0;
+
 sub new
 {
     my $proto=shift;
@@ -23,8 +39,14 @@ sub new
     my $self={};
     bless($self,$class);
 
+    $self->{elements}=[];
     $self->{db}=shift;
     $self->{path}=shift;
+    $self->{verbose}=shift;
+    $self->{maxtagdepth}=shift;
+    $self->{curtagdepth}=0;
+    $self->{path} =~ s/\/\//\//g; # drop doubled slashes
+
     $self->parse();
 #    print "STATE: ", $self->state(), "\n";
     return $self;
@@ -44,8 +66,7 @@ sub isdir
 sub isfile
 {
     my($self)=@_;
-    return 1 if($self->state() == $STATE_FILE);
-    return 0;
+    return($self->state() == $STATE_FILE);
 }
 
 sub isvalid
@@ -59,7 +80,7 @@ sub dest
     my($self, $mountpoint)=@_;
     if($self->state() == $STATE_FILE)
     {
-	return $self->{db}->filename($mountpoint, @{$self->{elements}});
+	return $self->filename($mountpoint);
     }
     return "ERROR"; #should never happen?
 }
@@ -68,67 +89,74 @@ sub dirents
 {
     my($self)=@_;
     my @dents=();
+    my @fents=();
     my $state=$self->state();
 #    print "DIRENTS: STATE: $state\n";
 #    print "DIRENTS: FILE: $self->{path}\n";
-    if($state==$STATE_TAG || $state==$STATE_TAGVAL)
+    if($state==$STATE_ALL)
     {
-	my $tag=$self->{elements}->[$#{$self->{elements}}];
-	if($state==$STATE_TAG &&
-	   defined($tag) &&
-	   ref($tag) eq "ID3FS::PathElement::Tag" &&
-	   $self->{db}->tag_has_values($tag->{id}))
+	@dents=($self->filter($PATH_ALLTRACKS, $PATH_NOARTIST), $self->artists());
+    }
+    elsif($state==$STATE_TAG)
+    {
+	my $tail=$self->tail();
+	if($self->is($TYPE_TAG, $tail) && $self->{db}->tag_has_values($tail->id()))
 	{
-	    @dents=$self->{db}->tags(@{$self->{elements}});
+	    @dents=$self->tags();
 	}
 	else
 	{
-	    @dents=(qw(AND OR TRACKS NOARTIST),
-		    $self->{db}->artists(@{$self->{elements}}));
+	    if($self->{maxtagdepth} && ($self->{curtagdepth} < $self->{maxtagdepth}))
+	    {
+		@dents=qw(AND OR);
+	    }
+	    push(@dents, $self->filter($PATH_ALLTRACKS, $PATH_NOARTIST), $self->artists());
 	}
     }
     elsif($state==$STATE_BOOLEAN)
     {
-	my $parent=$self->{elements}->[$#{$self->{elements}}];
-	unless(defined($parent) &&
-	       ref($parent) eq "ID3FS::PathElement::Boolean" &&
-	       $parent->{name} eq "NOT")
+	my $parent=$self->tail();
+	unless($self->is($TYPE_BOOL, $parent) && $parent->{name} eq "NOT")
 	{
-	    push(@dents, "NOT");
+	    @dents=("NOT");
 	}
-	push(@dents, $self->{db}->tags(@{$self->{elements}}));
+	push(@dents,$self->tags());
     }
     elsif($state==$STATE_ROOT)
     {
-	@dents=(qw(ALL NOT), $self->{db}->tags(@{$self->{elements}}));
+	@dents=(qw(ALL NOT), $self->tags());
     }
     elsif($state==$STATE_ALBUMS)
     {
-	@dents=(qw(TRACKS NOALBUM),$self->{db}->albums(@{$self->{elements}}));
+	@dents=$self->filter($PATH_ALLTRACKS, $PATH_NOALBUM, $self->albums());
     }
     elsif($state==$STATE_TRACKLIST)
     {
-	@dents=$self->{db}->tracks(@{$self->{elements}});
+	@fents=$self->tracks();
     }
     else
     {
-	print "DIRENTS: UNHANDLED STATE: $state\n";
+	print "id3fsd: INTERNAL ERROR: DIRENTS: UNHANDLED STATE: $state\n";
     }
-    return(@dents);
+    return(\@dents, \@fents);
 }
 
+# State Machine Of Doom
 sub parse
 {
     my($self)=@_;
+    $self->state($STATE_ROOT);
+    return if($self->{path} eq "/");
     @{$self->{components}}=split(/\//, $self->{path});
     shift @{$self->{components}}; # drop empty field before leading /
 #    print "PATH: $self->{path}\n";
-    $self->state($STATE_ROOT);
-    return if($self->{path} eq "/");
     my @parts=@{$self->{components}};
     my($tag, $tagval);
     $self->{elements}=[];
-    while(my $name=shift @parts)
+    $self->{in_all}=0;
+    my $root_not=0;
+    my $tags_seen=0;
+    while(defined(my $name=shift @parts))
     {
 #	print "NAME: $name\n";
 	my $state=$self->state();
@@ -142,19 +170,22 @@ sub parse
 #	    print "SM: ROOT: $name\n";
 	    if($name eq "ALL")
 	    {
-		$self->state($STATE_TAG);
+		$self->{in_all}=1;
+		$self->state($STATE_ALL);
 	    }
 	    elsif($name eq "NOT")
 	    {
-	        push(@{$self->{elements}}, ID3FS::PathElement::Boolean->new($self->{db}, $name));
+		$root_not=1;
+	        push(@{$self->{elements}}, ID3FS::Path::Node->new($self->{db}, $TYPE_BOOL, $name));
 		$self->state($STATE_BOOLEAN);
 	    }
 	    else
 	    {
-		$tag=ID3FS::PathElement::Tag->new($self->{db}, $name);
+		$tag=ID3FS::Path::Node->new($self->{db}, $TYPE_TAG, $name);
 		if($tag)
 		{
 		    push(@{$self->{elements}}, $tag);
+		    $tags_seen++;
 		    $self->state($STATE_TAG);
 		}
 		else
@@ -163,19 +194,16 @@ sub parse
 		}
 	    }
 	}
-	elsif($state==$STATE_TAG || $state==$STATE_TAGVAL)
+	elsif($state==$STATE_TAG)
 	{
+	    my $tag=$self->tail();
 #	    print "SM: TAG/TAGVAL($state): $name\n";
-	    my $tag=$self->{elements}->[$#{$self->{elements}}];
-	    if($state==$STATE_TAG &&
-	       defined($tag) &&
-	       ref($tag) eq "ID3FS::PathElement::Tag" &&
-	       $self->{db}->tag_has_values($tag->{id}))
+	    if($self->is($TYPE_TAG, $tag) && $self->{db}->tag_has_values($tag->id()))
 	    {
-		my $tagval=ID3FS::PathElement::Tag->new($self->{db}, $name, $tag->{id});
+#		print "Parsing: parent: $tag->id()\n";
+		my $tagval=ID3FS::Path::Node->new($self->{db}, $TYPE_TAG, $name, $tag->id());
 		if(defined($tagval))
 		{
-		    $self->state($STATE_TAGVAL);
 		    # stay in tag state
 		    push(@{$self->{elements}}, $tagval);
 		}
@@ -184,27 +212,27 @@ sub parse
 		    $self->state($STATE_INVALID);
 		}
 	    }
-	    elsif($name eq "TRACKS")
+	    elsif($name eq $PATH_ALLTRACKS)
 	    {
 		$self->state($STATE_TRACKLIST);
 	    }
-	    elsif($name eq "NOARTIST")
+	    elsif($name eq $PATH_NOARTIST)
 	    {
 		$self->state($STATE_TRACKLIST);
 	    }
 	    elsif($name eq "AND")
 	    {
 		$self->state($STATE_BOOLEAN);
-	        push(@{$self->{elements}}, ID3FS::PathElement::Boolean->new($self->{db}, $name));
+	        push(@{$self->{elements}}, ID3FS::Path::Node->new($self->{db}, $TYPE_BOOL, $name));
 	    }
 	    elsif($name eq "OR")
 	    {
 		$self->state($STATE_BOOLEAN);
-	        push(@{$self->{elements}}, ID3FS::PathElement::Boolean->new($self->{db}, $name));
+	        push(@{$self->{elements}}, ID3FS::Path::Node->new($self->{db}, $TYPE_BOOL, $name));
 	    }
 	    else
 	    {
-		my $artist=ID3FS::PathElement::Artist->new($self->{db}, $name);
+		my $artist=ID3FS::Path::Node->new($self->{db}, $TYPE_ARTIST, $name);
 		if($artist)
 		{
 		    push(@{$self->{elements}}, $artist);
@@ -219,10 +247,9 @@ sub parse
 	elsif($state==$STATE_BOOLEAN)
 	{
 #	    print "SM: BOOLEAN: $name\n";
-	    my $parent=$self->{elements}->[$#{$self->{elements}}];
+	    my $parent=$self->tail();
 	    my $allownot=1;
-	    if(defined($parent) &&
-	       ref($parent) eq "ID3FS::PathElement::Boolean" &&
+	    if($self->is($TYPE_BOOL, $parent) &&
 	       $parent->{name} eq "NOT")
 	    {
 		$allownot=0;
@@ -230,14 +257,15 @@ sub parse
 	    if($allownot && $name eq "NOT")
 	    {
 		$self->state($STATE_BOOLEAN);
-	        push(@{$self->{elements}}, ID3FS::PathElement::Boolean->new($self->{db}, $name));
+	        push(@{$self->{elements}}, ID3FS::Path::Node->new($self->{db}, $TYPE_BOOL, $name));
 	    }
 	    else
 	    {
-		my $tag=ID3FS::PathElement::Tag->new($self->{db}, $name);
+		my $tag=ID3FS::Path::Node->new($self->{db}, $TYPE_TAG, $name);
 		if($tag)
 		{
 		    push(@{$self->{elements}}, $tag);
+		    $tags_seen++;
 		    $self->state($STATE_TAG);
 		}
 		else
@@ -249,17 +277,17 @@ sub parse
 	elsif($state==$STATE_ALBUMS)
 	{
 #	    print "SM: ALBUM: $name\n";
-	    if($name eq "TRACKS")
+	    if($name eq $PATH_ALLTRACKS)
 	    {
 		$self->state($STATE_TRACKLIST);
 	    }
-	    elsif($name eq "NOALBUM")
+	    elsif($name eq $PATH_NOALBUM)
 	    {
 		$self->state($STATE_TRACKLIST);
 	    }
 	    else
 	    {
-		my $album=ID3FS::PathElement::Album->new($self->{db}, $name);
+		my $album=ID3FS::Path::Node->new($self->{db}, $TYPE_ALBUM, $name);
 		if($album)
 		{
 		    push(@{$self->{elements}}, $album);
@@ -274,7 +302,7 @@ sub parse
 	elsif($state==$STATE_TRACKLIST)
 	{
 #	    print "SM: TRACKLIST: $name\n";
-	    my $track=ID3FS::PathElement::File->new($self->{db}, $name);
+	    my $track=ID3FS::Path::Node->new($self->{db}, $TYPE_FILE, $name);
 	    if($track)
 	    {
 		push(@{$self->{elements}}, $track);
@@ -291,46 +319,137 @@ sub parse
 	    # Can't have anything after a filename
 	    $self->state($STATE_INVALID);
 	}
+	elsif($state==$STATE_ALL)
+	{
+	    if($name eq $PATH_ALLTRACKS)
+	    {
+		$self->state($STATE_TRACKLIST);
+	    }
+	    elsif($name eq $PATH_NOARTIST)
+	    {
+		$self->state($STATE_TRACKLIST);
+	    }
+	    else
+	    {
+		my $artist=ID3FS::Path::Node->new($self->{db}, $TYPE_ARTIST, $name);
+		if($artist)
+		{
+		    push(@{$self->{elements}}, $artist);
+		    $self->state($STATE_ALBUMS);
+		}
+		else
+		{
+		    $self->state($STATE_INVALID);
+		}
+	    }
+	}
 	else
 	{
 	    print "SM: ERROR: UNKNOWN STATE: $self->{state}\n";
 	    $self->state($STATE_INVALID);
 	}
     }
+
+    my @elements=@{$self->{elements}};
+    # remove trailing boolean
+    while(@elements && $self->is($TYPE_BOOL, $elements[$#elements]))
+    {
+	pop @elements;
+    }
+#    print "\nELEMENTS: ", join(' ', map { $_->name(); } @elements), "\n";
+    my @joins=$self->number_joins(@elements);
+    @joins=qw(INNER) unless(@joins);
+    $self->{joins}=\@joins;
+#    print "AFTER: ", join(' ', map { $_->name() . "(" . $_->{table} . ")"; } @elements), "\n";
+#    print "JOINS: ", join(', ', @joins), "\n";
     # sort elements by precedence
-    @{$self->{elements}}=$self->sort_elements(@{$self->{elements}});
-    my $thing=$self->elements_to_tree([ @{$self->{elements}} ]);
-    $self->{tagtree}=$self->elements_to_tree([ @{$self->{elements}} ]);
-#    print($self->{tagtree}->print(), "\n") if $self->{tagtree};
+    @elements=$self->sort_elements(@elements);
+    $self->{tagtree}=$self->elements_to_tree(\@elements);
+}
+
+sub number_joins
+{
+    my($self, @elements)=@_;
+    my @joins=("INNER");
+    my $table=1;
+    my $nextjoin=undef;
+    my $lastop=undef;
+    return (@joins) unless(@elements);
+    while(my $thing=shift @elements)
+    {
+	if($thing->type() == $TYPE_BOOL)
+	{
+	    my $op=$thing->name();
+	    if($op eq "AND")
+	    {
+		$nextjoin="INNER";
+	    }
+	    elsif($op eq "NOT")
+	    {
+		$nextjoin="LEFT";
+	    }
+	    elsif($op eq "OR")
+	    {
+		# NOT/foo/OR needs an extra join
+		$nextjoin="INNER" if($lastop && $lastop eq "NOT");
+	    }
+	    $lastop=$op;
+	}
+	else
+	{
+	    if(@elements)
+	    {
+		# if tag has a value, eat the tag, shifting to the value
+		$thing=shift(@elements) if($elements[0]->type() == $TYPE_TAG);
+	    }
+	    elsif($self->{db}->tag_has_values($thing->id()))
+	    {
+		# if the expression ends in a tag that has a value
+		# (ie we have the tag and want the value)
+		# use an INNER join even if we were in a NOT
+		$nextjoin="INNER" if($nextjoin);
+	    }
+	    if($nextjoin)
+	    {
+		$table++;
+		push(@joins, $nextjoin);
+		$nextjoin=undef;
+	    }
+	    $thing->table($table);
+	}
+    }
+    return @joins;
 }
 
 sub state
 {
     my($self, $newstate)=@_;
-    $self->{state}=$newstate if(defined($newstate));
+    if(defined($newstate))
+    {
+	$self->{state}=$newstate;
+	$self->{curtagdepth}++ if($newstate == $STATE_TAG);
+    }
     return $self->{state};
 }
 
+# link up precedence-sorted list into a binary tree
 sub elements_to_tree
 {
     my($self, $elements)=@_;
     return undef unless(@$elements);
     my ($left, $right, $op)=(undef, undef, undef);
     my $thing=pop @$elements;
-    if(ref($thing) eq "ID3FS::PathElement::Boolean")
+    if($self->is($TYPE_BOOL, $thing))
     {
-	my $op=$thing;
 	$right=$self->elements_to_tree($elements);
-	if($op->{name} ne "NOT")
+	if($thing->{name} ne "NOT")
 	{
 	    $left=$self->elements_to_tree($elements);
 	}
-	return ID3FS::Path::Node->new($left, $op, $right);
-    }
-    else
-    {
-	return ID3FS::Path::Node->new($thing);
+	$thing->left($left);
+	$thing->right($right);
     }
+    return $thing;
 }
 
 # Dijkstra's shunting-yard algorithm
@@ -339,46 +458,372 @@ sub sort_elements
     my ($self, @input)=@_;
     my @opstack=();
     my @output=();
-#    print "INPUT: ", join(', ', map { $_->{name}; } @input), "\n";
     while(my $thing = shift @input)
     {
-	if(ref($thing) eq "ID3FS::PathElement::Tag")
+	if($self->is($TYPE_TAG, $thing))
 	{
-#	    print "Pushing $thing->{name} to output\n";
+	    # Handle tag values by dropping parent
+	    if(@input && $self->is($TYPE_TAG, $input[0]))
+	    {
+		$thing=shift @input;
+	    }
 	    push(@output, $thing);
-#	    print "OPSTACK: ", join(', ', map { $_->{name}; } @opstack), "\n";
-#	    print "OUTPUT: ", join(', ', map { $_->{name}; } @output), "\n";
 	}
-	elsif(ref($thing) eq "ID3FS::PathElement::Boolean")
+	elsif($self->is($TYPE_BOOL, $thing))
 	{
-#	    print "BOOL: $thing->{name}\n";
-	    # bool
-#	    print "thing: $thing->{name}: $priorities{$thing->{name}} ";
-	    if(@opstack)
-	    {
-#		print("topop: ", $opstack[$#opstack]->{name},
-#		      ": ", $priorities{$opstack[$#opstack]->{name}}, "\n");
-	    }
 	    while(@opstack &&
 		  ($priorities{$thing->{name}} <= $priorities{$opstack[$#opstack]->{name}}))
 	    {
-#		print "Pushing ", $opstack[$#opstack]->{name}, " from opstack to output\n";
 		push(@output, pop(@opstack));
-#		print "OPSTACK: ", join(', ', map { $_->{name}; } @opstack), "\n";
-#		print "OUTPUT: ", join(', ', map { $_->{name}; } @output), "\n";
 	    }
-#	    print "Pushing $thing->{name} to opstack\n";
 	    push(@opstack, $thing);
-#	    print "OPSTACK: ", join(', ', map { $_->{name}; } @opstack), "\n";
-#	    print "OUTPUT: ", join(', ', map { $_->{name}; } @output), "\n";
 	}
     }
     while(@opstack)
     {
 	push(@output, pop(@opstack));
     }
-#    print "STACK: ", join(', ', map { $_->{name}; } @output), "\n";
     return @output;
 }
 
+sub used_tags
+{
+    my($self)=@_;
+    return() unless(defined($self->{tagtree}));
+    return($self->{tagtree}->used_tags());
+}
+
+sub expecting_values
+{
+    my($self)=@_;
+    my $tail=$self->tail();
+    if($self->is($TYPE_TAG, $tail))
+    {
+	return($self->{db}->tag_has_values($tail->id()));
+    }
+}
+
+sub trailing_tag_id
+{
+    my($self)=@_;
+    my $tail=$self->tail();
+    if($self->is($TYPE_TAG, $tail))
+    {
+	return($tail->id());
+    }
+    return undef;
+}
+
+sub trailing_tag_parent
+{
+    my($self)=@_;
+    my $tail=$self->tail();
+    if($self->is($TYPE_TAG, $tail))
+    {
+	return($tail->{parents_id});
+    }
+    return undef;
+}
+
+sub tail
+{
+    my($self)=@_;
+    return($self->{elements}->[$#{$self->{elements}}]);
+}
+
+sub is
+{
+    my($self, $type, $thing)=@_;
+    return 0 unless($thing);
+    return 0 unless($thing->type());
+    return 1 if($type == $thing->type());
+    return 0;
+}
+
+# the one before last
+sub tail_parent
+{
+    my($self)=@_;
+    return($self->{elements}->[($#{$self->{elements}}) - 1]);
+}
+
+######################################################################
+
+sub tags
+{
+    my($self)=@_;
+    if(!$self->{tagtree}) # / or /NOT
+    {
+	my $sql="SELECT DISTINCT name FROM tags WHERE parents_id='';";
+	return($self->{db}->cmd_firstcol($sql));
+    }
+    my $hasvals=$self->expecting_values();
+    my $sql="SELECT tags.name FROM ";
+    if($self->want_all_tags())
+    {
+	$sql .= "files_x_tags\n";
+    }
+    else
+    {
+	$sql .= ("(\n" .
+		 $self->tags_subselect() .
+		 ") AS subselect\n" .
+		 "INNER JOIN files_x_tags ON subselect.files_id=files_x_tags.files_id\n");
+    }
+    $sql .= "INNER JOIN tags ON files_x_tags.tags_id=tags.id\n";
+    my @andclauses=();
+    my $id=$self->trailing_tag_id();
+
+    my $parentclause= "tags.parents_id='";
+    $parentclause .= $id if($hasvals);
+    $parentclause .= "'";
+    push(@andclauses, $parentclause);
+
+    my @used=$self->used_tags();
+    if(@used)
+    {
+	push(@andclauses, "tags.id NOT IN (" . join(', ', @used) . ")");
+    }
+    if(@andclauses)
+    {
+	$sql .= "WHERE " . join(' AND ', @andclauses) . "\n";
+    }
+
+    $sql .= "GROUP BY tags.name;";
+    print "SQL(TAGS): $sql\n" if($self->{verbose});
+    my @tagnames=$self->{db}->cmd_firstcol($sql);
+    print("SUBNAMES: ", join(', ', @tagnames), "\n") if($self->{verbose});
+    return(@tagnames);
+}
+
+sub artists
+{
+    my($self)=@_;
+    if(!@{$self->{elements}}) # /ALL
+    {
+	my $sql="SELECT DISTINCT name FROM artists WHERE name!='';";
+	return($self->{db}->cmd_firstcol($sql));
+    }
+    my $sql=$self->sql_start("artists.name");
+    $sql .= ("INNER JOIN artists ON files.artists_id=artists.id\n" .
+	     "WHERE artists.name != ''\n" .
+	     "GROUP BY artists.name;");
+    print "SQL(ARTISTS): $sql\n" if($self->{verbose});
+    my @tagnames=$self->{db}->cmd_firstcol($sql);
+    print("ARTISTS: ", join(', ', @tagnames), "\n") if($self->{verbose});
+    return(@tagnames);
+}
+
+sub albums
+{
+    my($self)=@_;
+    my $tail=$self->tail();
+    if($self->is($TYPE_ARTIST, $tail))
+    {
+	return $self->artist_albums($tail->id());
+    }
+    my $sql=$self->sql_start("albums.name");
+    $sql .= ("INNER JOIN albums ON files.albums_id=albums.id\n" .
+	     "WHERE albums.name != ''\n" .
+	     "GROUP BY albums.name;");
+    print "SQL(ALBUMS): \n$sql\n" if($self->{verbose});
+    my @names=$self->{db}->cmd_firstcol($sql);
+    print("ALBUMS: ", join(', ', @names), "\n") if($self->{verbose});
+    return(@names);
+}
+
+sub artist_albums
+{
+    my($self, $artist_id)=@_;
+    my $sql=$self->sql_start("albums.name");
+    $sql .= ("INNER JOIN albums ON albums.id=files.albums_id\n" .
+	     "INNER JOIN artists ON artists.id=files.artists_id\n" .
+	     "WHERE artists.id=? and albums.name <> ''\n" .
+	     "GROUP BY albums.name\n");
+    print "ARTIST_ALBUMS SQL: $sql\n" if($self->{verbose});
+    my @albums=$self->{db}->cmd_firstcol($sql, $artist_id);
+    print("ALBUMS: ", join(', ', @albums), "\n") if($self->{verbose});
+    return(@albums);
+}
+
+sub artist_tracks
+{
+    my($self, $artist_id)=@_;
+    my $sql=$self->sql_start("files.name");
+    $sql .= ("INNER JOIN artists ON artists.id=files.artists_id\n" .
+	     "INNER JOIN albums  ON albums.id=files.albums_id\n" .
+	     "WHERE artists.id=? AND albums.name=''\n" .
+	     "GROUP BY files.name\n");
+    print "ARTIST_TRACKS SQL: $sql\n" if($self->{verbose});
+    my @names=$self->{db}->cmd_firstcol($sql, $artist_id);
+    print("ARTISTTRACKS: ", join(', ', @names), "\n") if($self->{verbose});
+    return(@names);
+}
+
+sub album_tracks
+{
+    my($self, $artist_id, $album_id)=@_;
+    my $sql=("SELECT files.name FROM files\n" .
+	     "INNER JOIN albums  ON albums.id=files.albums_id\n" .
+	     "INNER JOIN artists ON artists.id=files.artists_id\n" .
+	     "WHERE artists.id=? AND albums.id=?\n" .
+	     "GROUP BY files.name\n");
+    print "ALBUM_TRACKS SQL($artist_id, $album_id): $sql\n" if($self->{verbose});
+    my @names=$self->{db}->cmd_firstcol($sql, $artist_id, $album_id);
+    print("TRACKS: ", join(', ', @names), "\n") if($self->{verbose});
+    return(@names);
+}
+
+sub tracks
+{
+    my($self)=@_;
+    my $tail=$self->tail();
+    if($self->is($TYPE_ARTIST, $tail))
+    {
+	return $self->artist_tracks($tail->id());
+    }
+    elsif($self->is($TYPE_ALBUM, $tail))
+    {
+	my $artist_id=0;
+	my $artist=$self->tail_parent();
+	if($self->is($TYPE_ARTIST, $artist))
+	{
+	    # should always happen
+	    $artist_id=$artist->id();
+	}
+	return $self->album_tracks($artist_id, $tail->id());
+    }
+    my $sql=$self->sql_start("files.name");
+    $sql .= "INNER JOIN artists ON files.artists_id=artists.id\n";
+    if($self->{components}->[$#{$self->{components}}] eq $PATH_NOARTIST)
+    {
+	$sql .= "WHERE artists.name =''\n";
+    }
+    $sql .= "GROUP BY files.name;";
+    print "TRACKS SQL($self->{path}): $sql\n" if($self->{verbose});
+    my @names=$self->{db}->cmd_firstcol($sql);
+    print("TRACKS: ", join(', ', @names), "\n") if($self->{verbose});
+    return(@names);
+}
+
+sub filename
+{
+    my($self, $mountpoint)=@_;
+    my $tail=$self->tail();
+    if($self->is($TYPE_FILE, $tail))
+    {
+	my $id=$tail->id();
+	my $sql=("SELECT paths.name, files.name FROM files\n" .
+		 "INNER JOIN paths ON files.paths_id=paths.id\n" .
+		 "WHERE files.id=?\n" .
+		 "GROUP BY paths.name, files.name");
+	print "FILENAME SQL: $sql\n" if($self->{verbose});
+	my ($path, $name)=$self->{db}->cmd_onerow($sql, $id);
+	return($self->{db}->relativise($path, $name, $mountpoint, $self->{path}));
+    }
+    # should never happen
+    return "ERROR";
+}
+
+sub tags_subselect
+{
+    my($self)=@_;
+    my $hasvals=$self->expecting_values();
+    my $tree=$self->{tagtree};
+#    use Data::Dumper;
+#    print Dumper $tree;
+    my ($sqlclause, @joins)=$tree->to_sql($hasvals) if($tree);
+    my $sql="\tSELECT fxt1.files_id FROM tags t1";
+    my @crosses=();
+    my @inners=();
+    @joins=@{$self->{joins}};
+    for(my $i=0; $i <= $#joins; $i++)
+    {
+	my $cnt=$i+1;
+	my $join=$joins[$i];
+	my $inner=("\t$join JOIN files_x_tags fxt$cnt ON " .
+		   "t${cnt}.id=fxt${cnt}.tags_id");
+	if($i > 0)
+	{
+	    push(@crosses, "CROSS JOIN tags t$cnt");
+	    $inner .= " AND fxt1.files_id=fxt${cnt}.files_id";
+	}
+	push(@inners, $inner);
+    }
+    $sql .= ("\n\t" . join(" ", @crosses)) if(@crosses);
+    $sql .= ("\n" . join("\n", @inners)) if(@inners);
+    $sql .= "\n\tWHERE $sqlclause" if($sqlclause);
+    $sql .= "\n\tGROUP BY fxt1.files_id\n";
+    return $sql;
+}
+
+sub sql_start
+{
+    my($self, $tables)=@_;
+    my $sql="SELECT $tables FROM ";
+    if($self->{in_all})
+    {
+	$sql .= "files\n";
+    }
+    else
+    {
+	$sql .= ("(\n" .
+		 $self->tags_subselect() .
+		 ") AS subselect\n" .
+		 "INNER JOIN files ON subselect.files_id=files.id\n");
+    }
+    return $sql;
+}
+
+# we just filter $ALLTRACKS, $NOARTIST and $NOALBUM
+# filtering tags properly requires up to four levels of recursion
+# (tag/tagval/AND/NOT) and is too slow
+sub filter
+{
+    my($self, @dirs)=@_;
+    return(@dirs) unless($ENABLE_FILTER);
+    my $base=$self->{path};
+    my @outdirs=();
+    for my $dir (@dirs)
+    {
+	push(@outdirs, $dir) unless($self->empty("$base/$dir"));
+    }
+    return(@outdirs);
+}
+
+sub empty
+{
+    my($self, $dir)=@_;
+    my $path=ID3FS::Path->new($self->{db}, $dir, $self->{verbose},
+			      ($self->{maxtagdepth} - $self->{curtagdepth}));
+    return 1 unless($path->isvalid());
+    my($subdirs,$subfiles)=$path->dirents();
+    return 0 if(@$subfiles || @$subdirs);
+    return 1;
+}
+
+# if path is .../OR/ or .../OR/NOT or .../AND/NOT
+sub want_all_tags
+{
+    my($self)=@_;
+    my $tail=$self->tail();
+    return 0 unless($tail);
+    my $parent=$self->tail_parent();
+    my $parent_valid = ($parent && $parent->type() == $TYPE_BOOL);
+    if($tail->type() == $TYPE_BOOL)
+    {
+	return 1 if($tail->name() eq "OR");
+	return 0 unless($tail->name() eq "NOT");
+	return 0 unless($parent_valid);
+	return 1 if($parent->name() eq "OR");
+	return 1 if($parent->name() eq "AND");
+    }
+    elsif($tail->type() == $TYPE_TAG)
+    {
+	return 0 unless($parent_valid);
+	return 1 if($parent->name() eq "NOT");
+    }
+    return 0;
+}
+
 1;