X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=helm%2Fhttp_getter%2Fhttp_getter.pl.in;h=e73d9f9878689b039352916e90b29a0abcfcd303;hb=b564f0671c133928e372e352d972a7663b6a9136;hp=43c7ff0790ec3750ce8858c6a54e972071a269c9;hpb=985d664bf27762902b93a2158e755aeabe6ee27f;p=helm.git

diff --git a/helm/http_getter/http_getter.pl.in b/helm/http_getter/http_getter.pl.in
index 43c7ff079..e73d9f987 100755
--- a/helm/http_getter/http_getter.pl.in
+++ b/helm/http_getter/http_getter.pl.in
@@ -23,6 +23,8 @@
 # For details, see the HELM World-Wide-Web page,
 # http://cs.unibo.it/helm/.
 
+my $VERSION = "@VERSION@";
+
 # First of all, let's load HELM configuration
 use Env;
 my $HELM_LIB_DIR = $ENV{"HELM_LIB_DIR"};
@@ -38,28 +40,46 @@ if (defined ($HELM_LIB_DIR)) {
 # set the cache mode, may be "gzipped" or "normal"
 my $cachemode = $ENV{'HTTP_GETTER_CACHE_MODE'} || 'gzipped';
 if (($cachemode ne 'gzipped') and ($cachemode ne 'normal')) {
-	die "Invalid HTTP_GETTER_CACHE_MODE environment variable, must be 'normal' or 'gzipped'\n";
+ die "Invalid HTTP_GETTER_CACHE_MODE environment variable, must be".
+ "'normal' or 'gzipped'\n";
 }
 # </ZACK>
 
 # next require defines: $helm_dir, $html_link, $dtd_dir, $uris_dbm
 require $HELM_LIB_PATH;
 
+# Let's override the configuration file
+$style_dir = $ENV{"HELM_STYLE_DIR"} if (defined ($ENV{"HELM_STYLE_DIR"}));
+$dtd_dir = $ENV{"HELM_DTD_DIR"} if (defined ($ENV{"HELM_DTD_DIR"}));
+
 use HTTP::Daemon;
 use HTTP::Status;
 use HTTP::Request;
 use LWP::UserAgent;
 use DB_File;
 use Compress::Zlib;
+use CGI;
+use URI::Escape;
 
 #CSC: mancano i controlli sulle condizioni di errore di molte funzioni
 #CSC: ==> non e' robusto
 #CSC: altra roba da sistemare segnata con CSC
 
 my $d = new HTTP::Daemon LocalPort => 8081;
+my $myownurl = $d->url;
+
+# Let's patch the returned URL
+$myownurl =~ s/\/$//; # chop the final slash
+my $myownport = $myownurl;
+$myownport =~ s/http:\/\/(.*):(.*)/$2/;
+$myownurl  =~ s/http:\/\/(.*):(.*)/$1/;
+($myownurl) = gethostbyname($myownurl);
+$myownurl = "http://".$myownurl.":".$myownport;
+
 tie(%map, 'DB_File', $uris_dbm.".db", O_RDONLY, 0664);
-print "Please contact me at: <URL:", $d->url, ">\n";
+print "Please contact me at: <URL:", $myownurl."/", ">\n";
 print "helm_dir: $helm_dir\n";
+print "style_dir: $style_dir\n";
 print "dtd_dir: $dtd_dir\n";
 print "urls_of_uris.db: $uris_dbm.db\n";
 print "cache mode: $cachemode\n";
@@ -71,11 +91,15 @@ while (my $c = $d->accept) {
     while (my $r = $c->get_request) {
         #CSC: mancano i controlli di sicurezza
         
-        my $inputuri = $r->url; 
+        my $inputuri = uri_unescape($r->url); 
         $inputuri =~ s/^[^?]*\?uri=(.*)/$1/;
         print "\nRequest: ".$r->url."\n\n";
         my $http_method = $r->method;
         my $http_path = $r->url->path;
+        my $http_query = uri_unescape($r->url->query);
+        my $cgi = new CGI("$http_query");
+
+	print "\nUnescaped query: ".$http_query."\n";
 
         if ($http_method eq 'GET' and $http_path eq "/getciconly") {
             # finds the uri, url and filename
@@ -84,21 +108,19 @@ while (my $c = $d->accept) {
             my $cicfilename = $cicuri;
             $cicfilename =~ s/cic:(.*)/$1/;
             $cicfilename =~ s/theory:(.*)/$1/;
-#            $cicfilename = $helm_dir.$cicfilename.".xml";
-# <gzip>
+
             my $cicurl   = $map{$cicuri};
-			my $extension;
-			if ($cicurl =~ /\.xml$/) {	# non gzipped file
-					$extension = ".xml";
-			} elsif ($cicurl =~ /\.xml\.gz$/) {	# gzipped file
-					$extension = ".xml.gz";
-			} else {	# error: unknown extension
-				die "unexpected extension in url: $cicurl, might be '.xml' or '.xml.gz'";
-			}
+            my $extension;
+            if ($cicurl =~ /\.xml$/) { # non gzipped file
+              $extension = ".xml";
+            } elsif ($cicurl =~ /\.xml\.gz$/) { # gzipped file
+              $extension = ".xml.gz";
+            } else { # error: unknown extension
+             die "unexpected extension in url: $cicurl, might be '.xml'".
+              "or '.xml.gz'";
+            }
             $cicfilename = $helm_dir.$cicfilename.$extension;
 
-            #my $cicurl   = $map{$cicuri};
-# </gzip>
             if (!defined($cicurl)) {
              print "\nNOT FOUND!!!!!\n";
              $c->send_error(RC_NOT_FOUND)
@@ -138,45 +160,41 @@ while (my $c = $d->accept) {
             $cicfilename =~ s/theory:(.*)/$1/;
             $cicfilename = $helm_dir.$cicfilename;
 
-#            my $typesfilename = $cicfilename.".types.xml"     if $typesuri;
-#            my $annfilename  = $cicfilename.$annsuffix.".xml" if $annuri;
-#            $cicfilename .= ".xml";
-
-# <gzip>
             my $cicurl   = $map{$cicuri};
             my $typesurl = $map{$typesuri} if (defined($typesuri));
             my $annurl   = $map{$annuri}  if (defined($annuri));
-			my ($cicext, $typesext, $annext);
-			if ($cicurl =~ /\.xml$/) {	# normal file
-				$cicext = ".xml";
-			} elsif ($cicurl =~ /\.xml\.gz$/) {	# gzipped file
-				$cicext = ".xml.gz";
-			} else {
-				die "unexpected extension in url: $cicurl; might be '.xml' or '.xml.gz'";
-			}
-			if (defined($typesuri)) {	# extension selection for types file
-				if ($typesurl =~ /\.xml$/) {	# normal file
-					$typesext = ".types.xml";
-				} elsif ($typesurl =~ /\.xml\.gz$/) {	# gzipped file
-					$typesext = ".types.xml.gz";
-				} else {
-					die "unexpected extension in url: $typesurl; might be '.xml' or '.xml.gz'";
-				}
-			}
-			if (defined($annuri)) {	# extension selection for annotation file
-				if ($annurl =~ /\.xml$/) {	# normal file
-					$annext = ".xml";
-				} elsif ($annurl =~ /\.xml\.gz$/) {	# gzipped file
-					$annext = ".xml.gz";
-				} else {
-					die "unexpected extension in url: $annurl might be '.xml' or '.xml.gz'";
-				}
-			}
+            my ($cicext, $typesext, $annext);
+            if ($cicurl =~ /\.xml$/) { # normal file
+             $cicext = ".xml";
+            } elsif ($cicurl =~ /\.xml\.gz$/) { # gzipped file
+             $cicext = ".xml.gz";
+            } else {
+             die "unexpected extension in url: $cicurl;".
+             "might be '.xml' or '.xml.gz'";
+            }
+            if (defined($typesuri)) { # extension selection for types file
+             if ($typesurl =~ /\.xml$/) { # normal file
+              $typesext = ".types.xml";
+             } elsif ($typesurl =~ /\.xml\.gz$/) { # gzipped file
+              $typesext = ".types.xml.gz";
+             } else {
+              die "unexpected extension in url: $typesurl;".
+              "might be '.xml' or '.xml.gz'";
+             }
+            }
+            if (defined($annuri)) { # extension selection for annotation file
+             if ($annurl =~ /\.xml$/) { # normal file
+              $annext = ".xml";
+             } elsif ($annurl =~ /\.xml\.gz$/) { # gzipped file
+              $annext = ".xml.gz";
+             } else {
+              die "unexpected extension in url: $annurl".
+              "might be '.xml' or '.xml.gz'";
+             }
+            }
             my $typesfilename = $cicfilename.$typesext if $typesuri;
             my $annfilename  = $cicfilename.$annsuffix.$annext if $annuri;
             $cicfilename .= $cicext;
-# </gzip>
-
 
             if (!defined($cicurl) ||
                (!defined($typesurl) && $typesuri) ||
@@ -221,12 +239,52 @@ EOT
                print "Using local copy\n";
                open(FD, $filename) or die "Cannot open $filename\n";
                $cont = "";
-               while(<FD>) { $cont .= $_; }
+               while(<FD>) {
+                # Vary bad heuristic for substituion of absolute URLs
+                # for relative ones
+		s/ENTITY (.*) SYSTEM\s+"/ENTITY $1 SYSTEM "$myownurl\/getdtd?uri=/g;
+	        $cont .= $_;
+	       }
                close(FD);
                answer($c,$cont);
             } else {
                die "Could not find DTD!";
             }
+        } elsif ($http_method eq 'GET' and $http_path eq "/getstyleconf") {
+            my $filename = $inputuri;
+            $filename = $style_dir."/config/".$filename;
+            if (stat($filename)) {
+               open(FD, $filename) or die "Cannot open $filename\n";
+               $cont = "";
+               while(<FD>) {
+	        s/DOCTYPE (.*) SYSTEM\s+"/DOCTYPE $1 SYSTEM "$myownurl\/getstyleconf?uri=/g;
+	        $cont .= $_;
+	       }
+               close(FD);
+               answer($c,$cont);
+            } else {
+               die "Could not find Style Configuration File!";
+            }
+        } elsif ($http_method eq 'GET' and $http_path eq "/getxslt") {
+            my $filename = $inputuri;
+            $filename = $style_dir."/".$filename;
+            print "XSLT: $inputuri ==> ($filename)\n";
+            if (stat($filename)) {
+               print "Using local copy\n";
+               open(FD, $filename) or die "Cannot open $filename\n";
+               $cont = "";
+               while(<FD>) {
+                # Vary bad heuristic for substituion of absolute URLs
+                # for relative ones
+                s/xsl:import\s+href="/xsl:import href="$myownurl\/getxslt?uri=/g ;
+                s/xsl:include\s+href="/xsl:include href="$myownurl\/getxslt?uri=/g ;
+                $cont .= $_;
+               }
+               close(FD);
+               answer($c,$cont);
+            } else {
+               die "Could not find XSLT!";
+            }
         } elsif ($http_method eq 'GET' and $http_path eq "/conf") {
             my $quoted_html_link = $html_link;
             $quoted_html_link =~ s/&/&amp;/g;
@@ -238,13 +296,52 @@ EOT
 	    $cont = "<?xml version=\"1.0\"?><html_link>$quoted_html_link</html_link>";
             answer($c,$cont);
         } elsif ($http_method eq 'GET' and $http_path eq "/update") {
-           print "Update requested...";
-           update();
-           kill(USR1,getppid());
+            # rebuild urls_of_uris.db
+           print "Update requested...\n";
+           mk_urls_of_uris();
+           kill(USR1,getppid()); # signal changes to parent
            print " done\n";
            answer($c,"<html><body><h1>Update done</h1></body></html>");
+        } elsif ($http_method eq 'GET' and $http_path eq "/ls") {
+            # send back keys that begin with a given uri
+           my ($uritype,$uripattern,$uriprefix);
+           my $baseuri = $cgi->param('baseuri');
+           chop $baseuri if ($baseuri =~ /.*\/$/); # remove trailing "/"
+           my $outype = $cgi->param('format'); # output type, might be 'txt' or 'xml'
+           $uripattern = $baseuri;
+           $uripattern =~ s/^.*:(.*)/$1/;
+           if ($baseuri =~ /^cic:/) {
+            $uritype = "cic";
+           } elsif ($baseuri =~ /^theory:/) {
+            $uritype = "theory";
+           } else {
+            $uritype = "invalid";
+           }
+           if ($uritype ne "invalid") { # uri is valid
+            if (($outype ne 'txt') and ($outype ne 'xml')) { # invalid out type
+             print "Invalid output type specified: $outype\n";
+             answer($c,"<html><body><h1>Invalid output type, may be ".
+              "\"txt\" or \"xml\"</h1></body></html>");
+            } else { # valid output
+             print "BASEURI $baseuri, FORMAT $outype\n";
+             $cont = finduris($uritype,$uripattern,$outype);
+             answer($c,$cont);
+            }
+           } else { # invalid uri
+            print "Invalid uri: $baseuri, may begin with 'cic:', ".
+             "'theory:' or '*:'\n";
+            answer($c,"<html><body><h1>Invalid uri , may begin with ".
+             "\"cic:\", \"theory:\" or \"*:\"</h1></body></html>");
+           }
+        } elsif ($http_method eq 'GET' and $http_path eq "/version") {
+           print "Version requested!";
+           answer($c,"<html><body><h1>HTTP Getter Version ".
+            $VERSION."</h1></body></html>");
         } else {
-            print "\nINVALID REQUEST!!!!!\n";
+            print "\n";
+            print "INVALID REQUEST!!!!!\n";
+            print "(PATH: ",$http_path,", ";
+            print "QUERY: ",$http_query,")\n";
             $c->send_error(RC_FORBIDDEN)
         }
         print "\nRequest solved: ".$r->url."\n\n";
@@ -258,6 +355,117 @@ EOT
 
 #================================
 
+sub finduris { # find uris for cic and theory trees generation
+ my ($uritype,$uripattern,$format) = @_;
+ my $content = "";
+ my ($uri,$localpart,$basepart,$dirname,$suffix,$flags,$key);
+ my (@itemz,@already_pushed_dir);
+ my (%objects,%dirs); # map uris to suffixes' flags
+
+ print "FINDURIS, uritype: $uritype, uripattern: $uripattern, ".
+  "format: $format\n\n";
+ 
+ if (($uritype eq "cic") or ($uritype eq "theory")) {
+   # get info only of one type: cic or theory
+  foreach (keys(%map)) { # select matching uris
+   $uri = $_;
+   if ($uri =~ /^$uritype:$uripattern\//) {
+    $localpart = $uri;
+    $localpart =~ s/^$uritype:$uripattern\/(.*)/$1/;
+
+    if ($localpart =~ /^[^\/]*$/) { # no slash, an OBJECT
+     $basepart = $localpart;
+     $basepart =~ s/^(.*)\.types(\.ann)?/$1/; # remove exts .types or
+                                              # .types.ann
+     $flags = $objects{$basepart}; # get old flags
+     if ($localpart =~ /\.ann$/) {
+      $flags = add_flag("ann","YES",$flags);
+     } else {
+      $flags = add_flag("ann","NO",$flags);
+     }
+     if ($localpart =~ /\.types$/) {
+      $flags = add_flag("types","YES",$flags);
+     } elsif ($localpart =~ /\.types\.ann$/) {
+      $flags = add_flag("types","ANN",$flags);
+     } else {
+      $flags = add_flag("types","NO",$flags);
+     }
+     $objects{$basepart} = $flags; # save new flags
+    } else { # exists at least one slash, a DIR
+     ($dirname) = split (/\//, $localpart);
+     $dirs{$dirname} = ""; # no flags requirement for dir
+    }
+   }
+  }
+ } else {
+  die "getter internal error: unsupported uritype: \"$uritype\"";
+ }
+                            # now generate OUTPUT:
+                            # output will be saved in $content
+ if ($format eq "txt") { 
+  foreach $key (sort(keys %dirs)) {
+   $content .= "dir, " . $key . "\n";
+  }
+  foreach $key (sort(keys %objects)) {
+   $content .= "object, $key, " . $objects{$key} . "\n";
+  }
+ } elsif ($format eq "xml") {
+  $content .= "<ls>\n";
+  foreach $key (sort(keys %dirs)) {
+   $content .= "\t<section>$key</section>\n";
+  }
+  foreach $key (sort(keys %objects)) {
+   $content .= "\t<object name=\"$key\">\n";
+   $flags = $objects{$key};
+   $flags =~ s/^<(.*)>$/$1/;
+   my ($annflag,$typesflag) = split /,/,$flags;
+   $content .= "\t\t<ann value=\"$annflag\" />\n";
+   $content .= "\t\t<types value=\"$typesflag\" />\n";
+   $content .= "\t</object>\n";
+  }
+  $content .= "</ls>\n";
+ } else { # may not enter this branch
+  die "Getter internal error: invalid format received by finduris sub";
+ }
+ return $content;
+}
+
+sub add_flag {
+# manage string like: "<ann_flag,type_flag>"
+# "ann_flag" may be one of "ann_YES", "ann_NO"
+# "type_flag" may be one of "types_NO", "types_YES", "types_ANN"
+# when adding a flag the max between the current flag and the new flag
+# is taken, the orders are ann_NO < ann_YES and types_NO < types_YES <
+# types_ANN
+ my ($flagtype,$newflag,$str) = @_;
+ $str = "<,>" if ($str eq "");
+ ($str =~ s/^<(.*,.*)>$/$1/) or die "Internal error: ".
+   "wrong string format for flag adding in $str";
+ my ($annflag,$typeflag) = split /,/,$str;
+ if ($flagtype eq "ann") { # ANN flag handling
+  if ($newflag eq "YES") {
+   $annflag = "YES";
+  } elsif ($newflag eq "NO") {
+   $annflag = "NO" unless ($annflag eq "YES");
+  } else {
+   die "Internal error: annflag must be \"YES\" or \"NO\"";
+  }
+ } elsif ($flagtype eq "types") { # TYPES flag handling
+  if ($newflag eq "ANN") {
+   $typeflag = "ANN";
+  } elsif ($newflag eq "YES") {
+   $typeflag = "YES" unless ($typeflag eq "ANN");
+  } elsif ($newflag eq "NO") {
+   $typeflag = "NO"
+     unless (($typeflag eq "ANN") or ($typeflag eq "YES"));
+  } else {
+   die "Internal error: typeflag must be \"YES\", \"NO\" or \"ANN\"";
+  }
+ } else {
+  die "Internal error: unsupported flagtype \"$flagtype\"";
+ }
+ $str = "<$annflag,$typeflag>";
+}
 
 #CSC: Too much powerful: creates even /home, /home/users/, ...
 #CSC: Does not raise errors if could not create dirs/files
@@ -293,7 +501,8 @@ sub gunzip { # gunzip a file and return the deflated content
 	my ($gz, $buffer, $cont);
 
 	print "deflating $filename ...\n";
-	$gz = gzopen($filename, "r") or die "Cannot open gzip'ed file $filename: $gzerrno";
+	$gz = gzopen($filename, "r")
+		or die "Cannot open gzip'ed file $filename: $gzerrno";
 	$cont = "";
 	while ( $gz->gzread($buffer) > 0 ) {
 		$cont .= $buffer;
@@ -309,7 +518,8 @@ sub gzip {	# gzip the content argument and save it to filename argument
 
 	my ($gz, $cont);
 
-	$gz = gzopen($filename, "w") or die "Cannot gzopen for writing file $filename: $gzerrno";
+	$gz = gzopen($filename, "w")
+		or die "Cannot gzopen for writing file $filename: $gzerrno";
 	$gz->gzwrite($cont) or die "error writing: $gzerrno\n" ;
 	$gz->gzclose();
 }
@@ -317,7 +527,6 @@ sub gzip {	# gzip the content argument and save it to filename argument
 sub download
 {
  my ($remove_headers,$str,$url,$filename) = @_;
-# <gzip>
  my ($gz, $buffer);
 
  my $resourcetype;	# retrieve mode: "normal" (.xml) or "gzipped" (.xml.gz)
@@ -329,8 +538,7 @@ sub download
 	 die "Unsupported download extension, might be '.gz' or '.xml'\n";
  }
  my $basefname = $filename;
- $basefname =~ s/\.gz$//;		# get base resource name removing trailing .gz
-# </gzip>
+ $basefname =~ s/\.gz$//;	# get base resource name removing trailing .gz
  $cont = ""; # modified by side-effect by the callback function
 
  my $localfname="";
@@ -339,63 +547,66 @@ sub download
  } elsif (stat($basefname.".gz")) {
  	$localfname=$basefname.".gz";
  }
- if ($localfname ne "") {		# we already have local copy of requested file
-								# check both possible cache entry: gzipped or normal
-    print "Using local copy for the $str file\n";
-# <gzip>
-	if ($localfname =~ /\.xml\.gz$/) {	# deflating cached file and return it
-		$cont = gunzip($localfname);
-	} elsif ($localfname =~ /\.xml$/) {	# just return cached file
-		open(FD, $localfname) or die "Cannot open $localfname";
-		while(<FD>) { $cont .= $_; }
-		close(FD);
-	} else {	# error
-		die "Internal error: unexpected file name $localfname, must end with '.gz' or '.xml.gz'\n";
-	}
-# </gzip>
- } else {	# download file from net
-    print "Downloading the $str file\n";	# download file
-    $ua = LWP::UserAgent->new;
-    $request = HTTP::Request->new(GET => "$url");
-    $response = $ua->request($request, \&callback);
+ if ($localfname ne "") { # we already have local copy of requested file
+      # check both possible cache entry: gzipped or normal
+  print "Using local copy for the $str file\n";
+  if ($localfname =~ /\.xml\.gz$/) { # deflating cached file and return it
+   $cont = gunzip($localfname);
+  } elsif ($localfname =~ /\.xml$/) { # just return cached file
+   open(FD, $localfname) or die "Cannot open $localfname";
+   while(<FD>) { $cont .= $_; }
+   close(FD);
+  } else { # error
+   die "Internal error: unexpected file name $localfname,"
+   ."must end with '.gz' or '.xml.gz'\n";
+  }
+ } else { # download file from net
+    print "Downloading the $str file\n"; # download file
+    my $ua = LWP::UserAgent->new;
+    my $request = HTTP::Request->new(GET => "$url");
+    my $response = $ua->request($request, \&callback);
                
-				# cache retrieved file to disk
-# <ZACK/> TODO: inefficent, I haven't yet undestood how to deflate in memory gzipped file,
-#				without call "gzopen"
-# <gzip>
-	print "Storing the $str file\n";
-	mkdirs($filename);
-	open(FD, ">".$filename.".tmp") or die "Cannot open $filename.tmp\n";
-	print FD $cont;
-	close(FD);
-
-	# handle cache conversion normal->gzipped or gzipped->normal as user choice
-	if (($cachemode eq 'normal') and ($resourcetype eq 'normal')) {	# cache the file as is
-		rename "$filename.tmp", $filename;	
-	} elsif (($cachemode eq 'gzipped') and ($resourcetype eq 'gzipped')) {	# cache the file as is
-											# and update the $cont variabile with deflated content
-		rename "$filename.tmp", $filename;	
-		$cont = gunzip($filename);
-	} elsif (($cachemode eq 'normal') and ($resourcetype eq 'gzipped')) {	# deflate cache entry
-																			# and update $cont
-		open(FD, "> $basefname") or die "cannot open $basefname\n";
-		$cont = gunzip($filename.".tmp");
-		print FD $cont;
-		close(FD);
-		unlink "$filename.tmp";	# delete old gzipped file
-	} elsif (($cachemode eq 'gzipped') and ($resourcetype eq 'normal')) {	# compress cache entry
-		gzip($cont, $basefname.".gz");
-		unlink "$filename.tmp";	# delete old uncompressed file
-	} else {
-		die "Internal error, unsopported cachemode, resourcetype couple\n";
-	}
-	# $cont now contained uncompressed data
+    # cache retrieved file to disk
+# <ZACK/> TODO: inefficent, I haven't yet undestood how to deflate
+#    in memory gzipped file, without call "gzopen"
+ print "Storing the $str file\n";
+ mkdirs($filename);
+ open(FD, ">".$filename.".tmp") or die "Cannot open $filename.tmp\n";
+ print FD $cont;
+ close(FD);
+
+ # handle cache conversion normal->gzipped or gzipped->normal as user choice
+ if (($cachemode eq 'normal') and ($resourcetype eq 'normal')) {
+   # cache the file as is
+  rename "$filename.tmp", $filename; 
+ } elsif (($cachemode eq 'gzipped') and ($resourcetype eq 'gzipped')) {
+   # cache the file as is
+   # and update the $cont variabile with deflated content
+  rename "$filename.tmp", $filename; 
+  $cont = gunzip($filename);
+ } elsif (($cachemode eq 'normal') and ($resourcetype eq 'gzipped')) {
+   # deflate cache entry
+   # and update $cont
+  open(FD, "> $basefname") or die "cannot open $basefname\n";
+  $cont = gunzip($filename.".tmp");
+  print FD $cont;
+  close(FD);
+  unlink "$filename.tmp"; # delete old gzipped file
+ } elsif (($cachemode eq 'gzipped') and ($resourcetype eq 'normal')) {
+   # compress cache entry
+  gzip($cont, $basefname.".gz");
+  unlink "$filename.tmp"; # delete old uncompressed file
+ } else {
+  die "Internal error, unsopported cachemode, resourcetype couple\n";
+ }
+ # $cont now contained uncompressed data
 
-# </gzip>
  }
  if ($remove_headers) {
     $cont =~ s/<\?xml [^?]*\?>//sg;
     $cont =~ s/<!DOCTYPE [^>]*>//sg;
+ } else {
+    $cont =~ s/DOCTYPE (.*) SYSTEM\s+"http:\/\/www.cs.unibo.it\/helm\/dtd\//DOCTYPE $1 SYSTEM "$myownurl\/getdtd?uri=/g;
  }
  return $cont;
 }
@@ -408,7 +619,71 @@ sub answer
  $c->send_response($res);
 }
 
+sub helm_wget {
+#retrieve a file from an url and write it to a temp dir
+#used for retrieve resource index from servers
+ $cont = "";
+ my ($prefix, $URL) = @_;
+ my $ua = LWP::UserAgent->new;
+ my $request = HTTP::Request->new(GET => "$URL");
+ my $response = $ua->request($request, \&callback);
+ my ($filename) = reverse (split "/", $URL); # get filename part of the URL
+ open (TEMP, "> $prefix/$filename")
+  || die "Cannot open temporary file: $prefix/$filename\n";
+ print TEMP $cont;
+ close TEMP;
+}
+
 sub update {
  untie %map;
  tie(%map, 'DB_File', $uris_dbm.".db", O_RDONLY, 0664);
 }
+
+sub mk_urls_of_uris {
+#rebuild $uris_dbm.db fetching resource indexes from servers
+ my (
+  $server, $idxfile, $uri, $url, $comp, $line,
+  @servers,
+  %urls_of_uris
+ );
+
+ untie %map;
+ if (stat $uris_dbm.".db") { # remove old db file
+  unlink($uris_dbm.".db") or
+   die "cannot unlink old db file: $uris_dbm.db\n";
+ }
+ tie(%urls_of_uris, 'DB_File', $uris_dbm.".db", O_RDWR|O_CREAT, 0664);
+
+ open (SRVS, "< $servers_file") or
+  die "cannot open servers file: $servers_file\n";
+ @servers = <SRVS>;
+ close (SRVS);
+ while ($server = pop @servers) { #cicle on servers in reverse order
+  print "processing server: $server ...\n";
+  chomp $server;
+  helm_wget($tmp_dir, $server."/".$indexname); #get index
+  $idxfile = $tmp_dir."/".$indexname;
+  open (INDEX, "< $idxfile") or
+   die "cannot open temporary index file: $idxfile\n";
+  while ($line = <INDEX>) { #parse index and add entry to urls_of_uris
+   chomp $line;
+   ($uri,$comp) = split /[ \t]+/, $line;
+             # build url:
+   if ($comp =~ /gz/) { 
+    $url = $uri . ".xml" . ".gz";
+   } else {
+    $url = $uri . ".xml";
+   }
+   $url =~ s/cic:/$server/;
+   $url =~ s/theory:/$server/;
+   $urls_of_uris{$uri} = $url;
+  }
+  close INDEX;
+  die "cannot unlink temporary file: $idxfile\n"
+   if (unlink $idxfile) != 1;
+ }
+
+ untie(%urls_of_uris);
+ tie(%map, 'DB_File', $uris_dbm.".db", O_RDONLY, 0664);
+}
+