--- rat/lonuserstate.pm	2005/07/15 12:29:07	1.95
+++ rat/lonuserstate.pm	2007/08/28 01:09:14	1.121
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Construct and maintain state and binary representation of course for user
 #
-# $Id: lonuserstate.pm,v 1.95 2005/07/15 12:29:07 www Exp $
+# $Id: lonuserstate.pm,v 1.121 2007/08/28 01:09:14 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -31,9 +31,9 @@ package Apache::lonuserstate;
 
 # ------------------------------------------------- modules used by this module
 use strict;
-use Apache::Constants qw(:common :http);
 use HTML::TokeParser;
 use Apache::lonnet;
+use Apache::lonlocal;
 use Apache::loncommon();
 use GDBM_File;
 use Apache::lonmsg;
@@ -41,6 +41,9 @@ use Safe;
 use Safe::Hole;
 use Opcode;
 use Apache::lonenc;
+use Fcntl qw(:flock);
+use LONCAPA;
+ 
 
 # ---------------------------------------------------- Globals for this package
 
@@ -49,7 +52,8 @@ my %hash;    # The big tied hash
 my %parmhash;# The hash with the parameters
 my @cond;    # Array with all of the conditions
 my $errtext; # variable with all errors
-my $retfurl; # variable with the very first URL in the course
+my $retfrid; # variable with the very first RID in the course
+my $retfurl; # first URL
 my %randompick; # randomly picked resources
 my %randompickseed; # optional seed for randomly picking resources
 my %encurl; # URLs in this folder are supposed to be encrypted
@@ -93,9 +97,9 @@ sub processversionfile {
     my %versions=&Apache::lonnet::dump('resourceversions',
 				       $cenv{'domain'},
 				       $cenv{'num'});
-    foreach (keys %versions) {
-	if ($_=~/^error\:/) { return; }
-	$hash{'version_'.$_}=$versions{$_};
+    foreach my $ver (keys(%versions)) {
+	if ($ver=~/^error\:/) { return; }
+	$hash{'version_'.$ver}=$versions{$ver};
     }
 }
 
@@ -103,8 +107,12 @@ sub processversionfile {
 
 sub loadmap { 
     my $uri=shift;
-    if ($hash{'map_pc_'.$uri}) { return OK; }
-
+    if ($hash{'map_pc_'.$uri}) { 
+	$errtext.='<p class="LC_error">'.
+	    &mt('Multiple use of sequence/page [_1]! The course will not function properly.','<tt>'.$uri.'</tt>').
+	    '</p>';
+	return; 
+    }
     $pc++;
     my $lpc=$pc;
     $hash{'map_pc_'.$uri}=$lpc;
@@ -117,8 +125,8 @@ sub loadmap {
 
     unless (($fn=~/\.sequence$/) ||
             ($fn=~/\.page$/)) { 
-	$errtext.="Invalid map: $fn\n";
-	return OK; 
+	$errtext.=&mt("<br />Invalid map: <tt>[_1]</tt>",$fn);
+	return; 
     }
 
     my $instr=&Apache::lonnet::getfile($fn);
@@ -164,7 +172,9 @@ sub loadmap {
                         if ($token->[2]->{'external'} eq 'true') { # external
                             $turi=~s/^http\:\/\//\/adm\/wrapper\/ext\//;
                         } elsif ($turi=~/^\/*uploaded\//) { # uploaded
-			    if (($embstyle eq 'img') || ($embstyle eq 'emb')) {
+			    if (($embstyle eq 'img') 
+				|| ($embstyle eq 'emb')
+				|| ($embstyle eq 'wrp')) {
                                 $turi='/adm/wrapper'.$turi;
 			    } elsif ($embstyle eq 'ssi') {
 				#do nothing with these
@@ -175,7 +185,9 @@ sub loadmap {
 			    my $mapdir=$uri;
 			    $mapdir=~s/[^\/]+$//;
 			    $turi=&Apache::lonnet::hreflocation($mapdir,$turi);
-			    if (($embstyle eq 'img') || ($embstyle eq 'emb')) {
+			    if (($embstyle eq 'img') 
+				|| ($embstyle eq 'emb')
+				|| ($embstyle eq 'wrp')) {
 				$turi='/adm/wrapper'.$turi;
 			    }
                         }
@@ -273,22 +285,19 @@ sub loadmap {
 		    }
 		    $name=~s/^.*_([^_]*)$/$1/;
                     my $newparam=
-			&Apache::lonnet::escape($token->[2]->{'type'}).':'.
-			&Apache::lonnet::escape($part.'.'.$name).'='.
-			&Apache::lonnet::escape($token->[2]->{'value'});
+			&escape($token->[2]->{'type'}).':'.
+			&escape($part.'.'.$name).'='.
+			&escape($token->[2]->{'value'});
                     if (defined($hash{'param_'.$referid})) {
                         $hash{'param_'.$referid}.='&'.$newparam;
                     } else {
                         $hash{'param_'.$referid}=''.$newparam;
                     }
-                    if ($token->[2]->{'name'}=~/^parameter_(0_)*mapalias$/) {
-			$hash{'mapalias_'.$token->[2]->{'value'}}=$referid;
-                    }
                     if ($token->[2]->{'name'}=~/^parameter_(0_)*randompick$/) {
 			$randompick{$referid}=$token->[2]->{'value'};
                     }
                     if ($token->[2]->{'name'}=~/^parameter_(0_)*randompickseed$/) {
-			$randompick{$referid}=$token->[2]->{'value'};
+			$randompickseed{$referid}=$token->[2]->{'value'};
                     }
                     if ($token->[2]->{'name'}=~/^parameter_(0_)*encrypturl$/) {
 			if ($token->[2]->{'value'}=~/^yes$/i) {
@@ -306,7 +315,28 @@ sub loadmap {
         }
 
     } else {
-        $errtext.='Map not loaded: The file ('.$fn.') does not exist. ';
+        $errtext.=&mt('<br />Map not loaded: The file <tt>[_1]</tt> does not exist.',$fn);
+    }
+
+    my $parser = HTML::TokeParser->new(\$instr);
+    $parser->attr_encoded(1);
+    # last parse out the mapalias params so as to ignore anything
+    # refering to non-existant resources
+    while (my $token = $parser->get_token) {
+	next if ($token->[0] ne 'S');
+	if ($token->[1] eq 'param') {
+	    &parse_mapalias_param($token,$lpc);
+	} 
+    }
+}
+
+sub parse_mapalias_param {
+    my ($token,$lpc) = @_;
+    my $referid=$lpc.'.'.$token->[2]->{'to'};
+    return if (!exists($hash{'src_'.$referid}));
+
+    if ($token->[2]->{'name'}=~/^parameter_(0_)*mapalias$/) {
+	$hash{'mapalias_'.$token->[2]->{'value'}}=$referid;
     }
 }
 
@@ -314,20 +344,22 @@ sub loadmap {
 
 sub simplify {
     my $expression=shift;
+# (0&1) = 1
+    $expression=~s/\(0\&([_\.\d]+)\)/$1/g;
 # (8)=8
-    $expression=~s/\((\d+)\)/$1/g;
+    $expression=~s/\(([_\.\d]+)\)/$1/g;
 # 8&8=8
-    $expression=~s/(\D)(\d+)\&\2(\D)/$1$2$3/g;
+    $expression=~s/([^_\.\d])([_\.\d]+)\&\2([^_\.\d])/$1$2$3/g;
 # 8|8=8
-    $expression=~s/(\D)(\d+)\|\2(\D)/$1$2$3/g;
+    $expression=~s/([^_\.\d])([_\.\d]+)\|\2([^_\.\d])/$1$2$3/g;
 # (5&3)&4=5&3&4
-    $expression=~s/\((\d+)((?:\&\d+)+)\)\&(\d+\D)/$1$2\&$3/g;
+    $expression=~s/\(([_\.\d]+)((?:\&[_\.\d]+)+)\)\&([_\.\d]+[^_\.\d])/$1$2\&$3/g;
 # (((5&3)|(4&6)))=((5&3)|(4&6))
     $expression=~
-	s/\((\(\(\d+(?:\&\d+)*\)(?:\|\(\d+(?:\&\d+)*\))+\))\)/$1/g;
+	s/\((\(\([_\.\d]+(?:\&[_\.\d]+)*\)(?:\|\([_\.\d]+(?:\&[_\.\d]+)*\))+\))\)/$1/g;
 # ((5&3)|(4&6))|(1&2)=(5&3)|(4&6)|(1&2)
     $expression=~
-	s/\((\(\d+(?:\&\d+)*\))((?:\|\(\d+(?:\&\d+)*\))+)\)\|(\(\d+(?:\&\d+)*\))/\($1$2\|$3\)/g;
+	s/\((\([_\.\d]+(?:\&[_\.\d]+)*\))((?:\|\([_\.\d]+(?:\&[_\.\d]+)*\))+)\)\|(\([_\.\d]+(?:\&[_\.\d]+)*\))/\($1$2\|$3\)/g;
     return $expression;
 }
 
@@ -336,7 +368,7 @@ sub simplify {
 sub traceroute {
     my ($sofar,$rid,$beenhere,$encflag,$hdnflag)=@_;
     my $newsofar=$sofar=simplify($sofar);
-    unless ($beenhere=~/\&$rid\&/) {
+    unless ($beenhere=~/\&\Q$rid\E\&/) {
 	$beenhere.=$rid.'&';  
 	my ($mapid,$resid)=split(/\./,$rid);
 	my $symb=&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,$hash{'src_'.$rid});
@@ -351,10 +383,9 @@ sub traceroute {
 
 	my $encrypt=&Apache::lonnet::EXT('resource.0.encrypturl',$symb);
 	if ($encflag || lc($encrypt) eq 'yes') { $encurl{$rid}=1; }
-	if (($retfurl eq '') && ($hash{'src_'.$rid})
+	if (($retfrid eq '') && ($hash{'src_'.$rid})
 	    && ($hash{'src_'.$rid}!~/\.sequence$/)) {
-	    $retfurl=$hash{'src_'.$rid}.(($hash{'src_'.$rid}=~/\?/)?'&':'?').
-		'symb='.$symb;
+	    $retfrid=$rid;
 	}
 	if (defined($hash{'conditions_'.$rid})) {
 	    $hash{'conditions_'.$rid}=simplify(
@@ -362,7 +393,11 @@ sub traceroute {
 	} else {
 	    $hash{'conditions_'.$rid}=$sofar;
 	}
-	$newsofar=$hash{'conditions_'.$rid};
+
+	# if the expression is just the 0th condition keep it
+	# otherwise leave a pointer to this condition expression
+	$newsofar = ($sofar eq '0') ? $sofar : '_'.$rid;
+
 	if (defined($hash{'is_map_'.$rid})) {
 	    if (defined($hash{'map_start_'.$hash{'src_'.$rid}})) {
 		$sofar=$newsofar=
@@ -373,18 +408,17 @@ sub traceroute {
 	    }
 	}
 	if (defined($hash{'to_'.$rid})) {
-	    foreach (split(/\,/,$hash{'to_'.$rid})) {
+	    foreach my $id (split(/\,/,$hash{'to_'.$rid})) {
 		my $further=$sofar;
-                if ($hash{'undercond_'.$_}) {
-		    if (defined($hash{'condid_'.$hash{'undercond_'.$_}})) {
-			$further=simplify('('.$further.')&('.
-					  $hash{'condid_'.$hash{'undercond_'.$_}}.')');
+                if ($hash{'undercond_'.$id}) {
+		    if (defined($hash{'condid_'.$hash{'undercond_'.$id}})) {
+			$further=simplify('('.'_'.$rid.')&('.
+					  $hash{'condid_'.$hash{'undercond_'.$id}}.')');
 		    } else {
-			$errtext.='Undefined condition ID: '
-			    .$hash{'undercond_'.$_}.'. ';
+			$errtext.=&mt('<br />Undefined condition ID: [_1]',$hash{'undercond_'.$id});
 		    }
                 }
-                $newsofar=&traceroute($further,$hash{'goesto_'.$_},$beenhere,
+                $newsofar=&traceroute($further,$hash{'goesto_'.$id},$beenhere,
 				      $encflag,$hdnflag);
 	    }
 	}
@@ -400,51 +434,47 @@ sub accinit {
     my %captured=();
     my $condcounter=0;
     $acchash{'acc.cond.'.$short.'.0'}=0;
-    foreach (keys %hash) {
-	if ($_=~/^conditions/) {
-	    my $expr=$hash{$_};
-	    foreach ($expr=~m/(\(\(\d+(?:\&\d+)+\)(?:\|\(\d+(?:\&\d+)+\))+\))/g) {
-		my $sub=$_;
-		my $orig=$_;
-		$sub=~/\(\((\d+\&(:?\d+\&)*)(?:\d+\&*)+\)(?:\|\(\1(?:\d+\&*)+\))+\)/;
-		my $factor=$1;
-		$sub=~s/$factor//g;
+    foreach my $key (keys(%hash)) {
+	if ($key=~/^conditions/) {
+	    my $expr=$hash{$key};
+	    # try to find and factor out common sub-expressions
+	    foreach my $sub ($expr=~m/(\(\([_\.\d]+(?:\&[_\.\d]+)+\)(?:\|\([_\.\d]+(?:\&[_\.\d]+)+\))+\))/g) {
+		my $orig=$sub;
+
+		my ($factor) = ($sub=~/\(\(([_\.\d]+\&(:?[_\.\d]+\&)*)(?:[_\.\d]+\&*)+\)(?:\|\(\1(?:[_\.\d]+\&*)+\))+\)/);
+		next if (!defined($factor));
+
+		$sub=~s/\Q$factor\E//g;
 		$sub=~s/^\(/\($factor\(/;
 		$sub.=')';
 		$sub=simplify($sub);
-		$orig=~s/(\W)/\\$1/g;
-		$expr=~s/$orig/$sub/;
+		$expr=~s/\Q$orig\E/$sub/;
 	    }
-	    $hash{$_}=$expr;
+	    $hash{$key}=$expr;
 	    unless (defined($captured{$expr})) {
 		$condcounter++;
 		$captured{$expr}=$condcounter;
 		$acchash{'acc.cond.'.$short.'.'.$condcounter}=$expr;
 	    } 
-	} elsif ($_=~/^param_(\d+)\.(\d+)/) {
+	} elsif ($key=~/^param_(\d+)\.(\d+)/) {
 	    my $prefix=&Apache::lonnet::encode_symb($hash{'map_id_'.$1},$2,
 						    $hash{'src_'.$1.'.'.$2});
-	    foreach (split(/\&/,$hash{$_})) {
-		my ($typename,$value)=split(/\=/,$_);
+	    foreach my $param (split(/\&/,$hash{$key})) {
+		my ($typename,$value)=split(/\=/,$param);
 		my ($type,$name)=split(/\:/,$typename);
-		$parmhash{$prefix.'.'.&Apache::lonnet::unescape($name)}=
-		    &Apache::lonnet::unescape($value);
-		$parmhash{$prefix.'.'.&Apache::lonnet::unescape($name).'.type'}=
-		    &Apache::lonnet::unescape($type);
+		$parmhash{$prefix.'.'.&unescape($name)}=
+		    &unescape($value);
+		$parmhash{$prefix.'.'.&unescape($name).'.type'}=
+		    &unescape($type);
 	    }
 	}
     }
-    foreach (keys %hash) {
-	if ($_=~/^ids/) {
-	    foreach (split(/\,/,$hash{$_})) {
-		my $resid=$_;
+    foreach my $key (keys(%hash)) {
+	if ($key=~/^ids/) {
+	    foreach my $resid (split(/\,/,$hash{$key})) {
 		my $uri=$hash{'src_'.$resid};
-		$uri=~s/^\/adm\/wrapper//;
-		$uri=&Apache::lonnet::declutter($uri);
-		my @uriparts=split(/\//,$uri);
-		my $urifile=$uriparts[$#uriparts];
-		$#uriparts--;
-		my $uripath=join('/',@uriparts);
+		my ($uripath,$urifile) =
+		    &Apache::lonnet::split_uri_for_cond($uri);
 		if ($uripath) {
 		    my $uricond='0';
 		    if (defined($hash{'conditions_'.$resid})) {
@@ -456,8 +486,8 @@ sub accinit {
 			    my $replace=$1;
 			    my $regexp=$replace;
 			    #$regexp=~s/\|/\\\|/g;
-			    $acchash{'acc.res.'.$short.'.'.$uripath}
-			    =~s/\Q$regexp\E/$replace\|$uricond/;
+			    $acchash{'acc.res.'.$short.'.'.$uripath} =~
+				s/\Q$regexp\E/$replace\|$uricond/;
 			} else {
 			    $acchash{'acc.res.'.$short.'.'.$uripath}.=
 				$urifile.':'.$uricond.'&';
@@ -486,8 +516,8 @@ sub hiddenurls {
         my $mpc=$hash{'map_pc_'.$hash{'src_'.$rid}};
 # ------------------------------------------- put existing resources into array
         my @currentrids=();
-        foreach (sort(keys(%hash))) {
-	    if ($_=~/^src_($mpc\.\d+)/) {
+        foreach my $key (sort(keys(%hash))) {
+	    if ($key=~/^src_($mpc\.\d+)/) {
 		if ($hash{'src_'.$1}) { push @currentrids, $1; }
             }
         }
@@ -539,25 +569,31 @@ sub hiddenurls {
 sub readmap {
     my $short=shift;
     $short=~s/^\///;
-    my %cenv=&Apache::lonnet::coursedescription($short);
+    my %cenv=&Apache::lonnet::coursedescription($short,{'freshen_cache'=>1});
     my $fn=$cenv{'fn'};
     my $uri;
     $short=~s/\//\_/g;
     unless ($uri=$cenv{'url'}) { 
 	&Apache::lonnet::logthis("<font color=blue>WARNING: ".
 				 "Could not load course $short.</font>"); 
-	return 'No course data available.';
+	return ('',&mt('No course data available.'));;
     }
     @cond=('true:normal');
-    #unlink($fn.'.db');
-    #unlink($fn.'_symb.db');
-    unlink($fn.'.state');
-    unlink($fn.'parms.db');
+
+    open(LOCKFILE,">$fn.db.lock");
+    my $lock=0;
+    if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
+	$lock=1;
+	unlink($fn.'.db');
+	unlink($fn.'_symb.db');
+	unlink($fn.'.state');
+	unlink($fn.'parms.db');
+    }
     undef %randompick;
     undef %hiddenurl;
     undef %encurl;
-    $retfurl='';
-    if ((tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT(),0640)) &&
+    $retfrid='';
+    if ($lock && (tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT(),0640)) &&
 	(tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_WRCREAT(),0640))) {
 	%hash=();
 	%parmhash=();
@@ -574,23 +610,36 @@ sub readmap {
 	    &Apache::lonnet::appenv("request.course.id"  => $short,
 				    "request.course.fn"  => $fn,
 				    "request.course.uri" => $uri);
+	    $env{'request.course.id'}=$short;
 	    &traceroute('0',$hash{'map_start_'.$uri},'&');
 	    &accinit($uri,$short,$fn);
 	    &hiddenurls();
 	}
 # ------------------------------------------------------- Put versions into src
-	foreach (keys %hash) {
-	    if ($_=~/^src\_/) {
-		$hash{$_}=&putinversion($hash{$_});
+	foreach my $key (keys(%hash)) {
+	    if ($key=~/^src_/) {
+		$hash{$key}=&putinversion($hash{$key});
+	    } elsif ($key =~ /^(map_(?:start|finish|pc)_)(.*)/) {
+		my ($type, $url) = ($1,$2);
+		my $value = $hash{$key};
+		$hash{$type.&putinversion($url)}=$value;
 	    }
 	}
 # ---------------------------------------------------------------- Encrypt URLs
-	foreach (keys %encurl) {
-#	    $hash{'src_'.$_}=&Apache::lonenc::encrypted($hash{'src_'.$_});
-	    $hash{'encrypted_'.$_}=1;
+	foreach my $id (keys(%encurl)) {
+#	    $hash{'src_'.$id}=&Apache::lonenc::encrypted($hash{'src_'.$id});
+	    $hash{'encrypted_'.$id}=1;
 	}
 # ----------------------------------------------- Close hashes to finally store
 # --------------------------------- Routine must pass this point, no early outs
+	$hash{'first_rid'}=$retfrid;
+	my ($mapid,$resid)=split(/\./,$retfrid);
+	$hash{'first_mapurl'}=$hash{'map_id_'.$mapid};
+	my $symb=&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,$hash{'src_'.$retfrid});
+	$retfurl=&add_get_param($hash{'src_'.$retfrid},{ 'symb' => $symb });
+	if ($hash{'encrypted_'.$retfrid}) {
+	    $retfurl=&Apache::lonenc::encrypted($retfurl,(&Apache::lonnet::allowed('adv') ne 'F'));
+	}
 	$hash{'first_url'}=$retfurl;
 	unless ((untie(%hash)) && (untie(%parmhash))) {
 	    &Apache::lonnet::logthis("<font color=blue>WARNING: ".
@@ -605,13 +654,19 @@ sub readmap {
 		&Apache::lonnet::logthis("<font color=blue>WARNING: ".
 					 "Could not write statemap $fn for $uri.</font>"); 
 	    }
-	}  
+	}
+	flock(LOCKFILE,LOCK_UN);
+	close(LOCKFILE);
     } else {
 	# if we are here it is likely because we are already trying to 
 	# initialize the course in another child, busy wait trying to 
 	# tie the hashes for the next 90 seconds, if we succeed forward 
 	# them on to navmaps, if we fail, throw up the Could not init 
 	# course screen
+	if ($lock) {
+	    # Got the lock but not the DB files
+	    flock(LOCKFILE,LOCK_UN);
+	}
 	untie(%hash);
 	untie(%parmhash);
 	&Apache::lonnet::logthis("<font color=blue>WARNING: ".
@@ -620,7 +675,8 @@ sub readmap {
 	while($i<90) {
 	    $i++;
 	    sleep(1);
-	    if ((tie(%hash,'GDBM_File',"$fn.db",&GDBM_READER(),0640))) {
+	    if (flock(LOCKFILE,LOCK_EX|LOCK_NB) &&
+		(tie(%hash,'GDBM_File',"$fn.db",&GDBM_READER(),0640))) {
 		if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_READER(),0640)) {
 		    $retfurl='/adm/navmaps';
 		    &Apache::lonnet::appenv("request.course.id"  => $short,
@@ -634,6 +690,8 @@ sub readmap {
 	    untie(%hash);
 	    untie(%parmhash);
 	}
+	flock(LOCKFILE,LOCK_UN);
+	close(LOCKFILE);
     }
     &Apache::lonmsg::author_res_msg($env{'request.course.uri'},$errtext);
 # ------------------------------------------------- Check for critical messages
@@ -656,8 +714,9 @@ sub evalstate {
     if (-e $fn) {
 	my @conditions=();
 	{
-	    my $fh=Apache::File->new($fn);
+	    open(my $fh,"<$fn");
 	    @conditions=<$fh>;
+            close($fh);
 	}  
 	my $safeeval = new Safe;
 	my $safehole = new Safe::Hole;