--- loncom/lonnet/perl/lonnet.pm	2005/01/28 09:26:28	1.587.2.3
+++ loncom/lonnet/perl/lonnet.pm	2005/02/14 02:22:25	1.587.2.3.2.6
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.587.2.3 2005/01/28 09:26:28 albertel Exp $
+# $Id: lonnet.pm,v 1.587.2.3.2.6 2005/02/14 02:22:25 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -36,7 +36,7 @@ use HTTP::Date;
 # use Date::Parse;
 use vars 
 qw(%perlvar %hostname %homecache %badServerCache %hostip %iphost %spareid %hostdom 
-   %libserv %pr %prp %metacache %packagetab %titlecache %courseresversioncache %resversioncache
+   %libserv %pr %prp $memcache %packagetab 
    %courselogs %accesshash %userrolehash $processmarker $dumpcount 
    %coursedombuf %coursenumbuf %coursehombuf %coursedescrbuf %courseinstcodebuf %courseownerbuf %courseresdatacache 
    %userresdatacache %getsectioncache %domaindescription %domain_auth_def %domain_auth_arg_def 
@@ -50,6 +50,7 @@ use Fcntl qw(:flock);
 use Apache::lonlocal;
 use Storable qw(lock_store lock_nstore lock_retrieve freeze thaw nfreeze);
 use Time::HiRes qw( gettimeofday tv_interval );
+use Cache::Memcached;
 my $readit;
 my $max_connection_retries = 10;     # Or some such value.
 
@@ -923,6 +924,7 @@ sub save_cache_item {
 }
 
 sub save_cache {
+    &purge_remembered();
     if ($disk_caching_disabled) { return; }
     my ($cache,$name,$id);
     foreach $name (keys(%do_save)) {
@@ -1020,6 +1022,84 @@ EVALBLOCK
 #    &logthis("load_cache_item $name took ".(&Time::HiRes::time()-$starttime));
 }
 
+my $to_remember=10;
+my %remembered;
+my %accessed;
+my $kicks=0;
+my $hits=0;
+sub devalidate_cache_new {
+    my ($name,$id) = @_;
+    if (0) { &Apache::lonnet::logthis("deleting $name:$id"); }
+    $id=&escape($name.':'.$id);
+    $memcache->delete($id);
+    delete($remembered{$id});
+    delete($accessed{$id});
+}
+
+sub is_cached_new {
+    my ($name,$id,$debug) = @_;
+    $debug=0;
+    $id=&escape($name.':'.$id);
+    if (exists($remembered{$id})) {
+	if ($debug) { &Apache::lonnet::logthis("Earyl return $id of $remembered{$id} "); }
+	$accessed{$id}=[&gettimeofday()];
+	$hits++;
+	return ($remembered{$id},1);
+    }
+    my $value = $memcache->get($id);
+    if (!(defined($value))) {
+	if ($debug) { &Apache::lonnet::logthis("getting $id is not defined"); }
+	return (undef,undef);
+    }
+    &make_room($id,$value);
+    if ($value eq '__undef__') {
+	if ($debug) { &Apache::lonnet::logthis("getting $id is __undef__"); }
+	return (undef,1);
+    }
+    if ($debug) { &Apache::lonnet::logthis("getting $id is $value"); }
+    return ($value,1);
+}
+
+sub do_cache_new {
+    my ($name,$id,$value,$time,$debug) = @_;
+    $debug=0;
+    $id=&escape($name.':'.$id);
+    my $setvalue=$value;
+    if (!defined($setvalue)) {
+	$setvalue='__undef__';
+    }
+    if ($debug) { &Apache::lonnet::logthis("Setting $id to $value"); }
+    $memcache->set($id,$setvalue,300);
+    &make_room($id,$value);
+    return $value;
+}
+
+sub make_room {
+    my ($id,$value)=@_;
+    my $debug=0;
+    $remembered{$id}=$value;
+    $accessed{$id}=[&gettimeofday()];
+    if (scalar(keys(%remembered)) <= $to_remember) { return; }
+    my $to_kick;
+    my $max_time=0;
+    foreach my $other (keys(%accessed)) {
+	if (&tv_interval($accessed{$other}) > $max_time) {
+	    $to_kick=$other;
+	    $max_time=&tv_interval($accessed{$other});
+	}
+    }
+    delete($remembered{$to_kick});
+    delete($accessed{$to_kick});
+    $kicks++;
+    if ($debug) { &logthis("kicking $max_time $kicks\n"); }
+    return;
+}
+
+sub purge_remembered {
+    &logthis("Tossing ".scalar(keys(%remembered)));
+    undef(%remembered);
+    undef(%accessed);
+}
 # ------------------------------------- Read an entry from a user's environment
 
 sub userenvironment {
@@ -1057,7 +1137,7 @@ sub getversion {
 
 sub currentversion {
     my $fname=shift;
-    my ($result,$cached)=&is_cached(\%resversioncache,$fname,'resversion',600);
+    my ($result,$cached)=&is_cached_new('resversion',$fname);
     if (defined($cached)) { return $result; }
     my $author=$fname;
     $author=~s/\/home\/httpd\/html\/res\/([^\/]*)\/([^\/]*).*/$1\/$2/;
@@ -1070,7 +1150,7 @@ sub currentversion {
     if (($answer eq 'con_lost') || ($answer eq 'rejected')) {
 	return -1;
     }
-    return &do_cache(\%resversioncache,$fname,$answer,'resversion');
+    return &do_cache_new('resversion',$fname,$answer,600);
 }
 
 # ----------------------------- Subscribe to a resource, return URL if possible
@@ -4464,6 +4544,7 @@ sub add_prefix_and_part {
 
 # ---------------------------------------------------------------- Get metadata
 
+my %metaentry;
 sub metadata {
     my ($uri,$what,$liburi,$prefix,$depthcount)=@_;
     $uri=&declutter($uri);
@@ -4483,28 +4564,29 @@ sub metadata {
 # Everything is cached by the main uri, libraries are never directly cached
 #
     if (!defined($liburi)) {
-	my ($result,$cached)=&is_cached(\%metacache,$uri,'meta');
+	my ($result,$cached)=&is_cached_new('meta',$uri);
 	if (defined($cached)) { return $result->{':'.$what}; }
     }
     {
 #
 # Is this a recursive call for a library?
 #
-	if (! exists($metacache{$uri})) {
-	    $metacache{$uri}={};
-	}
+#	if (! exists($metacache{$uri})) {
+#	    $metacache{$uri}={};
+#	}
         if ($liburi) {
 	    $liburi=&declutter($liburi);
             $filename=$liburi;
         } else {
-	    &devalidate_cache(\%metacache,$uri,'meta');
+	    &devalidate_cache_new('meta',$uri);
+	    undef(%metaentry);
 	}
         my %metathesekeys=();
         unless ($filename=~/\.meta$/) { $filename.='.meta'; }
 	my $metastring;
 	if ($uri !~ m|^uploaded/|) {
 	    my $file=&filelocation('',&clutter($filename));
-	    push(@{$metacache{$uri.'.file'}},$file);
+	    #push(@{$metaentry{$uri.'.file'}},$file);
 	    $metastring=&getfile($file);
 	}
         my $parser=HTML::LCParser->new(\$metastring);
@@ -4521,10 +4603,10 @@ sub metadata {
 		    if (defined($token->[2]->{'id'})) { 
 			$keyroot.='_'.$token->[2]->{'id'}; 
 		    }
-		    if ($metacache{$uri}->{':packages'}) {
-			$metacache{$uri}->{':packages'}.=','.$package.$keyroot;
+		    if ($metaentry{':packages'}) {
+			$metaentry{':packages'}.=','.$package.$keyroot;
 		    } else {
-			$metacache{$uri}->{':packages'}=$package.$keyroot;
+			$metaentry{':packages'}=$package.$keyroot;
 		    }
 		    foreach (keys %packagetab) {
 			my $part=$keyroot;
@@ -4546,14 +4628,14 @@ sub metadata {
 			    if ($subp eq 'display') {
 				$value.=' [Part: '.$part.']';
 			    }
-			    $metacache{$uri}->{':'.$unikey.'.part'}=$part;
+			    $metaentry{':'.$unikey.'.part'}=$part;
 			    $metathesekeys{$unikey}=1;
-			    unless (defined($metacache{$uri}->{':'.$unikey.'.'.$subp})) {
-				$metacache{$uri}->{':'.$unikey.'.'.$subp}=$value;
+			    unless (defined($metaentry{':'.$unikey.'.'.$subp})) {
+				$metaentry{':'.$unikey.'.'.$subp}=$value;
 			    }
-			    if (defined($metacache{$uri}->{':'.$unikey.'.default'})) {
-				$metacache{$uri}->{':'.$unikey}=
-				    $metacache{$uri}->{':'.$unikey.'.default'};
+			    if (defined($metaentry{':'.$unikey.'.default'})) {
+				$metaentry{':'.$unikey}=
+				    $metaentry{':'.$unikey.'.default'};
 			    }
 			}
 		    }
@@ -4586,7 +4668,7 @@ sub metadata {
 			    foreach (sort(split(/\,/,&metadata($uri,'keys',
 							       $location,$unikey,
 							       $depthcount+1)))) {
-				$metacache{$uri}->{':'.$_}=$metacache{$uri}->{':'.$_};
+				$metaentry{':'.$_}=$metaentry{':'.$_};
 				$metathesekeys{$_}=1;
 			    }
 			}
@@ -4597,18 +4679,18 @@ sub metadata {
 			}
 			$metathesekeys{$unikey}=1;
 			foreach (@{$token->[3]}) {
-			    $metacache{$uri}->{':'.$unikey.'.'.$_}=$token->[2]->{$_};
+			    $metaentry{':'.$unikey.'.'.$_}=$token->[2]->{$_};
 			}
 			my $internaltext=&HTML::Entities::decode($parser->get_text('/'.$entry));
-			my $default=$metacache{$uri}->{':'.$unikey.'.default'};
+			my $default=$metaentry{':'.$unikey.'.default'};
 			if ( $internaltext =~ /^\s*$/ && $default !~ /^\s*$/) {
 		 # only ws inside the tag, and not in default, so use default
 		 # as value
-			    $metacache{$uri}->{':'.$unikey}=$default;
+			    $metaentry{':'.$unikey}=$default;
 			} else {
 		  # either something interesting inside the tag or default
                   # uninteresting
-			    $metacache{$uri}->{':'.$unikey}=$internaltext;
+			    $metaentry{':'.$unikey}=$internaltext;
 			}
 # end of not-a-package not-a-library import
 		    }
@@ -4625,7 +4707,7 @@ sub metadata {
 	    &metadata_create_package_def($uri,$key,'extension_'.$extension,
 					 \%metathesekeys);
 	}
-	if (!exists($metacache{$uri}->{':packages'})) {
+	if (!exists($metaentry{':packages'})) {
 	    foreach my $key (sort(keys(%packagetab))) {
 		#no specific packages well let's get default then
 		if ($key!~/^default&/) { next; }
@@ -4634,31 +4716,31 @@ sub metadata {
 	    }
 	}
 # are there custom rights to evaluate
-	if ($metacache{$uri}->{':copyright'} eq 'custom') {
+	if ($metaentry{':copyright'} eq 'custom') {
 
     #
     # Importing a rights file here
     #
 	    unless ($depthcount) {
-		my $location=$metacache{$uri}->{':customdistributionfile'};
+		my $location=$metaentry{':customdistributionfile'};
 		my $dir=$filename;
 		$dir=~s|[^/]*$||;
 		$location=&filelocation($dir,$location);
 		foreach (sort(split(/\,/,&metadata($uri,'keys',
 						   $location,'_rights',
 						   $depthcount+1)))) {
-		    $metacache{$uri}->{':'.$_}=$metacache{$uri}->{':'.$_};
+		    #$metaentry{':'.$_}=$metacache{$uri}->{':'.$_};
 		    $metathesekeys{$_}=1;
 		}
 	    }
 	}
-	$metacache{$uri}->{':keys'}=join(',',keys %metathesekeys);
-	&metadata_generate_part0(\%metathesekeys,$metacache{$uri},$uri);
-	$metacache{$uri}->{':allpossiblekeys'}=join(',',keys %metathesekeys);
-	&do_cache(\%metacache,$uri,$metacache{$uri},'meta');
+	$metaentry{':keys'}=join(',',keys %metathesekeys);
+	&metadata_generate_part0(\%metathesekeys,\%metaentry,$uri);
+	$metaentry{':allpossiblekeys'}=join(',',keys %metathesekeys);
+	&do_cache_new('meta',$uri,\%metaentry);
 # this is the end of "was not already recently cached
     }
-    return $metacache{$uri}->{':'.$what};
+    return $metaentry{':'.$what};
 }
 
 sub metadata_create_package_def {
@@ -4666,22 +4748,22 @@ sub metadata_create_package_def {
     my ($pack,$name,$subp)=split(/\&/,$key);
     if ($subp eq 'default') { next; }
     
-    if (defined($metacache{$uri}->{':packages'})) {
-	$metacache{$uri}->{':packages'}.=','.$package;
+    if (defined($metaentry{':packages'})) {
+	$metaentry{':packages'}.=','.$package;
     } else {
-	$metacache{$uri}->{':packages'}=$package;
+	$metaentry{':packages'}=$package;
     }
     my $value=$packagetab{$key};
     my $unikey;
     $unikey='parameter_0_'.$name;
-    $metacache{$uri}->{':'.$unikey.'.part'}=0;
+    $metaentry{':'.$unikey.'.part'}=0;
     $$metathesekeys{$unikey}=1;
-    unless (defined($metacache{$uri}->{':'.$unikey.'.'.$subp})) {
-	$metacache{$uri}->{':'.$unikey.'.'.$subp}=$value;
+    unless (defined($metaentry{':'.$unikey.'.'.$subp})) {
+	$metaentry{':'.$unikey.'.'.$subp}=$value;
     }
-    if (defined($metacache{$uri}->{':'.$unikey.'.default'})) {
-	$metacache{$uri}->{':'.$unikey}=
-	    $metacache{$uri}->{':'.$unikey.'.default'};
+    if (defined($metaentry{':'.$unikey.'.default'})) {
+	$metaentry{':'.$unikey}=
+	    $metaentry{':'.$unikey.'.default'};
     }
 }
 
@@ -4719,7 +4801,8 @@ sub gettitle {
     my $urlsymb=shift;
     my $symb=&symbread($urlsymb);
     if ($symb) {
-	my ($result,$cached)=&is_cached(\%titlecache,$symb,'title',600);
+	my $key=$ENV{'request.course.id'}."\0".$symb;
+	my ($result,$cached)=&is_cached_new('title',$key);
 	if (defined($cached)) { 
 	    return $result;
 	}
@@ -4734,7 +4817,7 @@ sub gettitle {
 	}
 	$title=~s/\&colon\;/\:/gs;
 	if ($title) {
-	    return &do_cache(\%titlecache,$symb,$title,'title');
+	    return &do_cache_new('title',$key,$title,600);
 	}
 	$urlsymb=$url;
     }
@@ -4848,8 +4931,7 @@ sub fixversion {
     my $uri=&clutter($fn);
     my $key=$ENV{'request.course.id'}.'_'.$uri;
 # is this cached?
-    my ($result,$cached)=&is_cached(\%courseresversioncache,$key,
-				    'courseresversion',600);
+    my ($result,$cached)=&is_cached_new('courseresversion',$key);
     if (defined($cached)) { return $result; }
 # unfortunately not cached, or expired
     if (tie(%bighash,'GDBM_File',$ENV{'request.course.fn'}.'.db',
@@ -4863,8 +4945,7 @@ sub fixversion {
  	}
  	untie %bighash;
     }
-    return &do_cache
-	(\%courseresversioncache,$key,&declutter($uri),'courseresversion');
+    return &do_cache_new('courseresversion',$key,&declutter($uri),600);
 }
 
 sub deversion {
@@ -5573,17 +5654,20 @@ sub correct_line_ends {
 sub goodbye {
    &logthis("Starting Shut down");
 #not converted to using infrastruture and probably shouldn't be
-   &logthis(sprintf("%-20s is %s",'%badServerCache',scalar(%badServerCache)));
+   &logthis(sprintf("%-20s is %s",'%badServerCache',length(&freeze(\%badServerCache))));
 #converted
-   &logthis(sprintf("%-20s is %s",'%metacache',scalar(%metacache)));
-   &logthis(sprintf("%-20s is %s",'%homecache',scalar(%homecache)));
-   &logthis(sprintf("%-20s is %s",'%titlecache',scalar(%titlecache)));
-   &logthis(sprintf("%-20s is %s",'%courseresdatacache',scalar(%courseresdatacache)));
+#   &logthis(sprintf("%-20s is %s",'%metacache',scalar(%metacache)));
+   &logthis(sprintf("%-20s is %s",'%homecache',length(&freeze(\%homecache))));
+#   &logthis(sprintf("%-20s is %s",'%titlecache',length(&freeze(\%titlecache))));
+   &logthis(sprintf("%-20s is %s",'%courseresdatacache',length(&freeze(\%courseresdatacache))));
 #1.1 only
-   &logthis(sprintf("%-20s is %s",'%userresdatacache',scalar(%userresdatacache)));
-   &logthis(sprintf("%-20s is %s",'%getsectioncache',scalar(%getsectioncache)));
-   &logthis(sprintf("%-20s is %s",'%courseresversioncache',scalar(%courseresversioncache)));
-   &logthis(sprintf("%-20s is %s",'%resversioncache',scalar(%resversioncache)));
+   &logthis(sprintf("%-20s is %s",'%userresdatacache',length(&freeze(\%userresdatacache))));
+   &logthis(sprintf("%-20s is %s",'%getsectioncache',length(&freeze(\%getsectioncache))));
+#   &logthis(sprintf("%-20s is %s",'%courseresversioncache',length(&freeze(\%courseresversioncache))));
+#   &logthis(sprintf("%-20s is %s",'%resversioncache',length(&freeze(\%resversioncache))));
+   &logthis(sprintf("%-20s is %s",'%remembered',length(&freeze(\%remembered))));
+   &logthis(sprintf("%-20s is %s",'kicks',$kicks));
+   &logthis(sprintf("%-20s is %s",'hits',$hits));
    &flushcourselogs();
    &logthis("Shutting down");
    return DONE;
@@ -5729,7 +5813,7 @@ BEGIN {
 
 }
 
-%metacache=();
+$memcache=new Cache::Memcached({'servers'=>['127.0.0.1:11211']});
 
 $processmarker='_'.time.'_'.$perlvar{'lonHostID'};
 $dumpcount=0;