X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2FID3FS%2FPath.pm;h=629c02adc94fdf8857cec1a7e7df123967669a83;hb=c8571ddb3cc1f9bce16c91838de17f27242d2f32;hp=076b6ca310d633567da2b9a9f2fd2e3f1e7a3514;hpb=a1b0cc1f04007f1e5d8c135096e59787d478b07c;p=id3fs.git

diff --git a/lib/ID3FS/Path.pm b/lib/ID3FS/Path.pm
index 076b6ca..629c02a 100644
--- a/lib/ID3FS/Path.pm
+++ b/lib/ID3FS/Path.pm
@@ -1,18 +1,36 @@
+# 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 feature 'switch';
-use ID3FS::PathElement::Artist;
-use ID3FS::PathElement::Album;
-use ID3FS::PathElement::Boolean;
-use ID3FS::PathElement::File;
-use ID3FS::PathElement::Tag;
-use ID3FS::PathElement::Tagval;
-
-our ($STATE_INVALID, $STATE_ROOT, $STATE_TAG, $STATE_TAGVAL,
-     $STATE_BOOLEAN, $STATE_ALBUMS, $STATE_TRACKLIST,
-     $STATE_FILE)=(0..7);
+use ID3FS::Path::Node;
+
+our ($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 = 1;
 
 sub new
 {
@@ -21,10 +39,16 @@ 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";
+#    print "STATE: ", $self->state(), "\n";
     return $self;
 }
 
@@ -42,8 +66,7 @@ sub isdir
 sub isfile
 {
     my($self)=@_;
-    return 1 if($self->state() == $STATE_FILE);
-    return 0;
+    return($self->state() == $STATE_FILE);
 }
 
 sub isvalid
@@ -54,10 +77,10 @@ sub isvalid
 
 sub dest
 {
-    my($self)=@_;
+    my($self, $mountpoint)=@_;
     if($self->state() == $STATE_FILE)
     {
-	return $self->{db}->filename(@{$self->{elements}});
+	return $self->filename($mountpoint);
     }
     return "ERROR"; #should never happen?
 }
@@ -66,148 +89,183 @@ sub dirents
 {
     my($self)=@_;
     my @dents=();
-    print "DIRENTS: STATE: ",  $self->state(), "\n";
-    given($self->state())
+    my @fents=();
+    my $state=$self->state();
+#    print "DIRENTS: STATE: $state\n";
+#    print "DIRENTS: FILE: $self->{path}\n";
+    if($state==$STATE_ALL)
     {
-	when($STATE_TAG)
-	{
-	    @dents=(qw(AND ALLTRACKS), # FIXME: NOT and OR
-		    $self->{db}->artists(@{$self->{elements}}));
-	}
-	when($STATE_BOOLEAN)
-	{
-	    @dents=$self->{db}->tags(@{$self->{elements}});
-	}
-	when($STATE_ROOT)
-	{
-	    @dents=("ALL", $self->{db}->tags(@{$self->{elements}}));
-	    print "\nDIRENTS: DENTS: ", join(", ", @dents),"\n\n";
-	}
-	when($STATE_ALBUMS)
+	@dents=($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=("TRACKS", $self->{db}->albums(@{$self->{elements}}));
+	    @dents=$self->tags();
 	}
-	when($STATE_TRACKLIST)
+	else
 	{
-	    @dents=$self->{db}->tracks(@{$self->{elements}});
+	    if($self->{maxtagdepth} && ($self->{curtagdepth} < $self->{maxtagdepth}))
+	    {
+		@dents=qw(AND OR);
+	    }
+	    push(@dents, $self->filter($PATH_ALLTRACKS, $PATH_NOARTIST), $self->artists());
 	}
-	default
+    }
+    elsif($state==$STATE_BOOLEAN)
+    {
+	my $parent=$self->tail();
+	unless($self->is($TYPE_BOOL, $parent) && $parent->{name} eq "NOT")
 	{
-	    print "DIRENTS: UNHANDLED STATE: $_\n";
+	    @dents=("NOT");
 	}
+	push(@dents,$self->tags());
+    }
+    elsif($state==$STATE_ROOT)
+    {
+	@dents=(qw(ALL NOT), $self->tags());
     }
-    return(@dents);
+    elsif($state==$STATE_ALBUMS)
+    {
+	@dents=$self->filter($PATH_ALLTRACKS, $PATH_NOALBUM, $self->albums());
+    }
+    elsif($state==$STATE_TRACKLIST)
+    {
+	@fents=$self->tracks();
+    }
+    else
+    {
+	print "id3fsd: INTERNAL ERROR: DIRENTS: UNHANDLED STATE: $state\n";
+    }
+    return(\@dents, \@fents);
 }
 
+# State Machine Of Doom
 sub parse
 {
     my($self)=@_;
-    @{$self->{components}}=split(/\//, $self->{path});
-    shift @{$self->{components}}; # drop empty field before leading /
-    print "PATH: $self->{path}\n";
-#    print "COMPONENTS: ", join(' | ', @{$self->{components}}), "\n";
     $self->state($STATE_ROOT);
     return if($self->{path} eq "/");
+    @{$self->{components}}=split(/\//, $self->{path});
+    shift @{$self->{components}}; # drop empty field before leading /
+#    print "PATH: $self->{path}\n";
     my @parts=@{$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: $name\n";
-	given($self->state())
+#	print "NAME: $name\n";
+	my $state=$self->state();
+	if($state==$STATE_INVALID)
+	{
+#	    print "SM: INVALID: $name\n";
+	    return;
+	}
+	elsif($state==$STATE_ROOT)
 	{
-	    when($STATE_INVALID)
+#	    print "SM: ROOT: $name\n";
+	    if($name eq "ALL")
 	    {
-		print "SM: INVALID: $name\n";
-		return;
+		$self->{in_all}=1;
+		$self->state($STATE_ALL);
 	    }
-	    when($STATE_ROOT)
+	    elsif($name eq "NOT")
 	    {
-		print "SM: ROOT: $name\n";
-		if($name eq "ALL")
+		$root_not=1;
+	        push(@{$self->{elements}}, ID3FS::Path::Node->new($self->{db}, $TYPE_BOOL, $name));
+		$self->state($STATE_BOOLEAN);
+	    }
+	    else
+	    {
+		$tag=ID3FS::Path::Node->new($self->{db}, $TYPE_TAG, $name);
+		if($tag)
 		{
+		    push(@{$self->{elements}}, $tag);
+		    $tags_seen++;
 		    $self->state($STATE_TAG);
 		}
 		else
 		{
-		    $tag=ID3FS::PathElement::Tag->new($self->{db}, $name);
-		    if($tag)
-		    {
-			push(@{$self->{elements}}, $tag);
-			$self->state($STATE_TAG);
-		    }
-		    else
-		    {
-			$self->state($STATE_INVALID);
-		    }
+		    $self->state($STATE_INVALID);
 		}
 	    }
-	    when($STATE_TAG)
+	}
+	elsif($state==$STATE_TAG)
+	{
+	    my $tag=$self->tail();
+#	    print "SM: TAG/TAGVAL($state): $name\n";
+	    if($self->is($TYPE_TAG, $tag) && $self->{db}->tag_has_values($tag->id()))
 	    {
-		print "SM: TAG: $name\n";
-		given($name)
+#		print "Parsing: parent: $tag->id()\n";
+		my $tagval=ID3FS::Path::Node->new($self->{db}, $TYPE_TAG, $name, $tag->id());
+		if(defined($tagval))
+		{
+		    # stay in tag state
+		    push(@{$self->{elements}}, $tagval);
+		}
+		else
 		{
-		    when("AND")
-		    {
-			$self->state($STATE_BOOLEAN);
-#			push(@{$self->{elements}}, ID3FS::PathElement::Boolean->new($name));
-		    }
-		    when("ALLTRACKS")
-		    {
-			$self->state($STATE_TRACKLIST);
-		    }
-		    when("OR")
-		    {
-			$self->state($STATE_BOOLEAN);
-#			push(@{$self->{elements}}, ID3FS::PathElement::Boolean->new($name));
-		    }
-		    when("NOT")
-		    {
-			$self->state($STATE_TAG);
-#			push(@{$self->{elements}}, ID3FS::PathElement::Boolean->new($name));
-		    }
-		    my $artist=ID3FS::PathElement::Artist->new($self->{db}, $name);
-		    if($artist)
-		    {
-			push(@{$self->{elements}}, $artist);
-			$self->state($STATE_ALBUMS);
-		    }
-		    else
-		    {
-			$self->state($STATE_INVALID);
-		    }
+		    $self->state($STATE_INVALID);
 		}
 	    }
-
-#	    when(255) #FIXME - dead code
-#	    {
-#		my @valid_tagvals=$self->{db}->tag_values($tag);
-#		print "TAGVALUES: $name: ", join(', ', @valid_tagvals), "\n";
-#		if(@valid_tagvals)
-#		{
-#		    if(grep { $name eq $_; } @valid_tagvals)
-#		    {
-#			print "TAGVAL VALID\n";
-#			$self->state($STATE_TAGVAL);
-#			push(@{$self->{elements}}, ID3FS::PathElement::Tagval($name));
-#		    }
-#		    else
-#		    {
-#			print "ERROR: unknown tagval: $tagval\n";
-#			$self->state($STATE_INVALID);
-#		    }
-#	    }
-	    when($STATE_TAGVAL)
+	    elsif($name eq $PATH_ALLTRACKS)
+	    {
+		$self->state($STATE_TRACKLIST);
+	    }
+	    elsif($name eq $PATH_NOARTIST)
+	    {
+		$self->state($STATE_TRACKLIST);
+	    }
+	    elsif($name eq "AND")
+	    {
+		$self->state($STATE_BOOLEAN);
+	        push(@{$self->{elements}}, ID3FS::Path::Node->new($self->{db}, $TYPE_BOOL, $name));
+	    }
+	    elsif($name eq "OR")
+	    {
+		$self->state($STATE_BOOLEAN);
+	        push(@{$self->{elements}}, ID3FS::Path::Node->new($self->{db}, $TYPE_BOOL, $name));
+	    }
+	    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);
+		}
+	    }
+	}
+	elsif($state==$STATE_BOOLEAN)
+	{
+#	    print "SM: BOOLEAN: $name\n";
+	    my $parent=$self->tail();
+	    my $allownot=1;
+	    if($self->is($TYPE_BOOL, $parent) &&
+	       $parent->{name} eq "NOT")
+	    {
+		$allownot=0;
+	    }
+	    if($allownot && $name eq "NOT")
 	    {
-		print "SM: TAGVAL: $name\n";
+		$self->state($STATE_BOOLEAN);
+	        push(@{$self->{elements}}, ID3FS::Path::Node->new($self->{db}, $TYPE_BOOL, $name));
 	    }
-	    when($STATE_BOOLEAN)
+	    else
 	    {
-		print "SM: BOOLEAN: $name\n";
-		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
@@ -215,62 +273,518 @@ sub parse
 		    $self->state($STATE_INVALID);
 		}
 	    }
-	    when($STATE_ALBUMS)
+	}
+	elsif($state==$STATE_ALBUMS)
+	{
+#	    print "SM: ALBUM: $name\n";
+	    if($name eq $PATH_ALLTRACKS)
+	    {
+		$self->state($STATE_TRACKLIST);
+	    }
+	    elsif($name eq $PATH_NOALBUM)
+	    {
+		$self->state($STATE_TRACKLIST);
+	    }
+	    else
 	    {
-		print "SM: ALBUM: $name\n";
-		if($name eq "TRACKS")
+		my $album=ID3FS::Path::Node->new($self->{db}, $TYPE_ALBUM, $name);
+		if($album)
 		{
+		    push(@{$self->{elements}}, $album);
 		    $self->state($STATE_TRACKLIST);
 		}
 		else
 		{
-		    my $album=ID3FS::PathElement::Album->new($self->{db}, $name);
-		    if($album)
-		    {
-			push(@{$self->{elements}}, $album);
-			$self->state($STATE_TRACKLIST);
-		    }
-		    else
-		    {
-			$self->state($STATE_INVALID);
-		    }
+		    $self->state($STATE_INVALID);
 		}
 	    }
-	    when($STATE_TRACKLIST)
+	}
+	elsif($state==$STATE_TRACKLIST)
+	{
+#	    print "SM: TRACKLIST: $name\n";
+	    my $track=ID3FS::Path::Node->new($self->{db}, $TYPE_FILE, $name);
+	    if($track)
 	    {
-		print "SM: TRACKLIST: $name\n";
-		my $track=ID3FS::PathElement::File->new($self->{db}, $name);
 		push(@{$self->{elements}}, $track);
-		if($track)
+		$self->state($STATE_FILE);
+	    }
+	    else
+	    {
+		$self->state($STATE_INVALID);
+	    }
+	}
+	elsif($state==$STATE_FILE)
+	{
+#	    print "SM: FILE: $name\n";
+	    # 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}}, $track);
-		    $self->state($STATE_FILE);
+		    push(@{$self->{elements}}, $artist);
+		    $self->state($STATE_ALBUMS);
 		}
 		else
 		{
 		    $self->state($STATE_INVALID);
 		}
 	    }
-	    when($STATE_FILE)
+	}
+	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;
+    }
+    # sort elements by precedence
+    @elements=$self->sort_elements(@elements);
+    $self->{tagtree}=$self->elements_to_tree(\@elements);
+}
+
+sub state
+{
+    my($self, $newstate)=@_;
+    if(defined($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($self->is($TYPE_BOOL, $thing))
+    {
+	$right=$self->elements_to_tree($elements);
+	if($thing->{name} ne "NOT")
+	{
+	    $left=$self->elements_to_tree($elements);
+	}
+	$thing->left($left);
+	$thing->right($right);
+    }
+    return $thing;
+}
+
+# Dijkstra's shunting-yard algorithm
+sub sort_elements
+{
+    my ($self, @input)=@_;
+    my @opstack=();
+    my @output=();
+#    print "INPUT: ", join(', ', map { $_->{name}; } @input), "\n";
+    while(my $thing = shift @input)
+    {
+	if($self->is($TYPE_TAG, $thing))
+	{
+	    # Handle tag values by dropping parent
+	    if(@input && $self->is($TYPE_TAG, $input[0]))
 	    {
-		print "SM: FILE: $name\n";
-		# Can't have anything after a filename
-		$self->state($STATE_INVALID);
+		$thing=shift @input;
 	    }
-	    default
+	    push(@output, $thing);
+	}
+	elsif($self->is($TYPE_BOOL, $thing))
+	{
+	    while(@opstack &&
+		  ($priorities{$thing->{name}} <= $priorities{$opstack[$#opstack]->{name}}))
 	    {
-		print "SM: ERROR: UNKNOWN STATE: $self->{state}\n";
-		$self->state($STATE_INVALID);
+		push(@output, pop(@opstack));
 	    }
+	    push(@opstack, $thing);
 	}
     }
+    while(@opstack)
+    {
+	push(@output, pop(@opstack));
+    }
+#    print "STACK: ", join(', ', map { $_->{name}; } @output), "\n";
+    return @output;
 }
 
-sub state
+sub used_tags
 {
-    my($self, $newstate)=@_;
-    $self->{state}=$newstate if(defined($newstate));
-    return $self->{state};
+    my($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 $parent=$self->trailing_tag_parent();
+#    print "THASVALS: $hasvals\n";
+#    print "TPARENT: ", (defined($parent)? $parent : "NO"), "\n";
+    my @ids=();
+    my $sql="SELECT tags.name FROM ";
+    if($self->in_or())
+    {
+	$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 $parentclause= "tags.parents_id='";
+    if($hasvals)
+    {
+	$parentclause .= $id;
+    }
+    elsif($parent)
+    {
+	$parentclause .= $parent;
+    }
+    $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 @ids=();
+    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 @ids=();
+    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};
+    my $parent=$self->trailing_tag_parent();
+
+    my $tag=undef;
+    if($hasvals)
+    {
+	$tag=$self->trailing_tag_id();
+#	print "Trailing id: $tag\n";
+    }
+    my ($sqlclause, @joins)=(undef, ());
+    ($sqlclause, @joins) = $tree->to_sql($hasvals) if($tree);
+#    use Data::Dumper;
+#    print Dumper $tree if($tree);
+#    print "SQL(" . scalar(@joins) ."): $sqlclause\n";
+    my $sql="\tSELECT fxt1.files_id FROM tags t1";
+    my @crosses=();
+    my @inners=();
+#    $joinsneeded++ if($tag);
+    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);
+#    if($tag)
+#    {
+#	$sql .= " AND t${joinsneeded}.parents_id='$tag'";
+#    }
+    $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 || @$subdirs);
+    return 1;
+}
+
+# if path is .../OR/ or .../OR/NOT
+sub in_or
+{
+    my($self)=@_;
+    my $tail=$self->tail();
+    return 0 unless($tail);
+    return 0 unless($tail->type() == $TYPE_BOOL);
+    return 1 if($tail->name() eq "OR");
+    return 0 unless($tail->name() eq "NOT");
+    my $parent=$self->tail_parent();
+    return 0 unless($parent);
+    return 0 unless($parent->type() == $TYPE_BOOL);
+    return 1 if($parent->name() eq "OR");
+    return 0;
 }
 
 1;