--- loncom/lonnet/perl/lonnet.pm	2002/08/23 21:31:09	1.273
+++ loncom/lonnet/perl/lonnet.pm	2002/09/17 21:19:19	1.285
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.273 2002/08/23 21:31:09 albertel Exp $
+# $Id: lonnet.pm,v 1.285 2002/09/17 21:19:19 matthew Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -348,12 +348,36 @@ sub delenv {
     return 'ok';
 }
 
+# ------------------------------------------ Fight off request when overloaded
+
+sub overloaderror {
+    my ($r,$checkserver)=@_;
+    unless ($checkserver) { $checkserver=$perlvar{'lonHostID'}; }
+    my $loadavg;
+    if ($checkserver eq $perlvar{'lonHostID'}) {
+       my $loadfile=Apache::File->new('/proc/loadavg');
+       $loadavg=<$loadfile>;
+       $loadavg =~ s/\s.*//g;
+       $loadavg = 100*$loadavg/$perlvar{'lonLoadLim'};
+    } else {
+       $loadavg=&reply('load',$checkserver);
+    }
+    my $overload=$loadavg-100;
+    if ($overload>0) {
+	$r->err_headers_out->{'Retry-After'}=$overload;
+        $r->log_error('Overload of '.$overload.' on '.$checkserver);
+        return 413;
+    }    
+    return '';
+}
+
 # ------------------------------ Find server with least workload from spare.tab
 
 sub spareserver {
+    my $loadpercent = shift;
     my $tryserver;
     my $spareserver='';
-    my $lowestserver=100;
+    my $lowestserver=$loadpercent; 
     foreach $tryserver (keys %spareid) {
        my $answer=reply('load',$tryserver);
        if (($answer =~ /\d/) && ($answer<$lowestserver)) {
@@ -871,7 +895,7 @@ sub countacc {
     my $url=&declutter(shift);
     unless ($ENV{'request.course.id'}) { return ''; }
     $accesshash{$ENV{'request.course.id'}.'___'.$url.'___course'}=1;
-    my $key=$processmarker.'_'.$dumpcount.'___'.$url.'___count';
+    my $key=$$.$processmarker.'_'.$dumpcount.'___'.$url.'___count';
     if (defined($accesshash{$key})) {
 	$accesshash{$key}++;
     } else {
@@ -2341,6 +2365,7 @@ sub createcourse {
     unless ($nonstandard) {
 # ------------------------------------------ For standard courses, make top url
         my $mapurl=&clutter($url);
+        if ($mapurl eq '/res/') { $mapurl=''; }
         $ENV{'form.initmap'}=(<<ENDINITMAP);
 <map>
 <resource id="1" type="start"></resource>
@@ -2458,6 +2483,30 @@ sub dirlist {
     }
 }
 
+# --------------------------------------------- GetFileTimestamp
+# This function utilizes dirlist and returns the date stamp for
+# when it was last modified.  It will also return an error of -1
+# if an error occurs
+
+sub GetFileTimestamp {
+    my ($studentDomain,$studentName,$filename,$root)=@_;
+    $studentDomain=~s/\W//g;
+    $studentName=~s/\W//g;
+    my $subdir=$studentName.'__';
+    $subdir =~ s/(.)(.)(.).*/$1\/$2\/$3/;
+    my $proname="$studentDomain/$subdir/$studentName";
+    $proname .= '/'.$filename;
+    my @dir = &Apache::lonnet::dirlist($proname, $studentDomain, $studentName,
+                                       $root);
+    my $fileStat = $dir[0];
+    my @stats = split('&', $fileStat);
+    if($stats[0] ne 'empty' && $stats[0] ne 'no_such_dir') {
+        return $stats[9];
+    } else {
+        return -1;
+    }
+}
+
 # -------------------------------------------------------- Value of a Condition
 
 sub directcondval {
@@ -2510,6 +2559,14 @@ sub condval {
     return $result;
 }
 
+# ---------------------------------------------------- Devalidate courseresdata
+
+sub devalidatecourseresdata {
+    my ($coursenum,$coursedomain)=@_;
+    my $hashid=$coursenum.':'.$coursedomain;
+    delete $courseresdatacache{$hashid.'.time'};
+}
+
 # --------------------------------------------------- Course Resourcedata Query
 
 sub courseresdata {
@@ -2541,7 +2598,7 @@ sub courseresdata {
 # --------------------------------------------------------- Value of a Variable
 
 sub EXT {
-    my ($varname,$symbparm,$udom,$uname)=@_;
+    my ($varname,$symbparm,$udom,$uname,)=@_;
 
     unless ($varname) { return ''; }
 
@@ -2698,10 +2755,16 @@ sub EXT {
 # --------------------------------------------- last, look in resource metadata
 
 	$spacequalifierrest=~s/\./\_/;
-	my $metadata=&metadata($ENV{'request.filename'},$spacequalifierrest);
+	my $filename;
+	if (!$symbparm) { $symbparm=&symbread(); }
+	if ($symbparm) {
+	    $filename=(split(/\_\_\_/,$symbparm))[2];
+	} else {
+	    $filename=$ENV{'request.filename'};
+	}
+	my $metadata=&metadata($filename,$spacequalifierrest);
 	if ($metadata) { return $metadata; }
-	$metadata=&metadata($ENV{'request.filename'},
-			    'parameter_'.$spacequalifierrest);
+	$metadata=&metadata($filename,'parameter_'.$spacequalifierrest);
 	if ($metadata) { return $metadata; }
 
 # ------------------------------------------------------------------ Cascade up
@@ -2750,7 +2813,7 @@ sub metadata {
 # Look at timestamp of caching
 # Everything is cached by the main uri, libraries are never directly cached
 #
-    unless (abs($metacache{$uri.':cachedtimestamp'}-time)<600) {
+    unless (abs($metacache{$uri.':cachedtimestamp'}-time)<600 && !defined($liburi)) {
 #
 # Is this a recursive call for a library?
 #
@@ -2773,7 +2836,7 @@ sub metadata {
 	      my $package=$token->[2]->{'package'};
 	      my $keyroot='';
               if ($prefix) {
-		  $keyroot.='_'.$prefix;
+		  $keyroot.=$prefix;
               } else {
                 if (defined($token->[2]->{'part'})) { 
                    $keyroot.='_'.$token->[2]->{'part'}; 
@@ -2831,12 +2894,14 @@ sub metadata {
 #
 # Importing a library here
 #                
-		 if (defined($depthcount)) { $depthcount++; } else 
-                                           { $depthcount=0; }
                  if ($depthcount<20) {
-		     foreach (split(/\,/,&metadata($uri,'keys',
-                                  $parser->get_text('/import'),$unikey,
-                                  $depthcount))) {
+		     my $location=$parser->get_text('/import');
+		     my $dir=$filename;
+		     $dir=~s|[^/]*$||;
+		     $location=&filelocation($dir,$location);
+		     foreach (sort(split(/\,/,&metadata($uri,'keys',
+							$location,$unikey,
+							$depthcount+1)))) {
                          $metathesekeys{$_}=1;
 		     }
 		 }
@@ -2861,8 +2926,9 @@ sub metadata {
 # the next is the end of "start tag"
 	 }
        }
-	&metadata_generate_part0(\%metathesekeys,\%metacache,$uri);
        $metacache{$uri.':keys'}=join(',',keys %metathesekeys);
+	&metadata_generate_part0(\%metathesekeys,\%metacache,$uri);
+       $metacache{$uri.':allpossiblekeys'}=join(',',keys %metathesekeys);
        $metacache{$uri.':cachedtimestamp'}=time;
 # this is the end of "was not already recently cached
     }
@@ -2934,7 +3000,7 @@ sub symbverify {
     my $okay=0;
     if (tie(%bighash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
                             &GDBM_READER(),0640)) {
-        my $ids=$bighash{'ids_/res/'.$thisfn};
+        my $ids=$bighash{'ids_'.&clutter($thisfn)};
         unless ($ids) { 
            $ids=$bighash{'ids_/'.$thisfn};
         }
@@ -3005,7 +3071,7 @@ sub symbread {
            if (tie(%bighash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
                             &GDBM_READER(),0640)) {
 # ---------------------------------------------- Get ID(s) for current resource
-              my $ids=$bighash{'ids_/res/'.$thisfn};
+              my $ids=$bighash{'ids_'.&clutter($thisfn)};
               unless ($ids) { 
                  $ids=$bighash{'ids_/'.$thisfn};
               }
@@ -3265,7 +3331,7 @@ BEGIN {
 
     while (my $configline=<$config>) {
        chomp($configline);
-       if (($configline) && ($configline ne $perlvar{'lonHostID'})) {
+       if ($configline) {
           $spareid{$configline}=1;
        }
     }
@@ -3313,7 +3379,7 @@ BEGIN {
 
 %metacache=();
 
-$processmarker=$$.'_'.time.'_'.$perlvar{'lonHostID'};
+$processmarker='_'.time.'_'.$perlvar{'lonHostID'};
 $dumpcount=0;
 
 &logtouch();