[LON-CAPA-cvs] cvs: loncom /xml lontexconvert.pm

[raeburn]

raeburn		Fri Jan  2 01:22:33 2009 EDT

  Modified files:              
    /loncom/xml	lontexconvert.pm 
  Log:
  - Use URI::Escape to escape the TeX string passed in the query string to mimetex.cgi.
  
  - Replace use of localhost.localdomain with hostname from &Apache::lonnet::hostname() for lonHostID.
  
  - Replace use of LWP with lower level IO::Socket::SSL and IO::Socket::INET for HEAD request for Vertical-Align from headers. (mimetex.cgi first pass).
     - Reason: mimetex_converted() can be called inside safespace (e.g., by &xmlparse('<m>stuff</m>' in a script block)
       - In this context call to open() - line 144 of HTTP/Request/Common.pm (called by $ua->head()) is trapped in safespace resulting in a run time error.
  
  - &Apache::lonxml::alarm() now used for timeouts.
    - Timeout args for IO::Socket::SSL/INETcan not be used because of dependency on fileno command at line 61 of IO/Select.pm (masked in safespace with run time error). 
  
  
Index: loncom/xml/lontexconvert.pm
diff -u loncom/xml/lontexconvert.pm:1.93 loncom/xml/lontexconvert.pm:1.94
--- loncom/xml/lontexconvert.pm:1.93	Thu Dec  4 19:53:53 2008
+++ loncom/xml/lontexconvert.pm	Fri Jan  2 01:22:33 2009
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # TeX Conversion Module
 #
-# $Id: lontexconvert.pm,v 1.93 2008/12/04 19:53:53 riegler Exp $
+# $Id: lontexconvert.pm,v 1.94 2009/01/02 01:22:33 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -47,8 +47,9 @@
 use Apache::lonnet;
 use lib '/home/httpd/lib/perl/';
 use LONCAPA;
-use LWP::UserAgent;
- 
+use URI::Escape;
+use IO::Socket::INET;
+use IO::Socket::SSL;
 
 # ====================================================================== Header
 
@@ -243,18 +244,40 @@
 }
 
 sub mimetex_valign {
-    my ($texstring)=@_;
-    my $ua = LWP::UserAgent->new; #from the perldoc of LWP::UserAgent
-    $ua->timeout(10); 
-    $ua->env_proxy;
-    #header without imagedata saved to response:
-    my $response = $ua->head('http://localhost.localdomain/cgi-bin/mimetex.cgi?'.$texstring);
-    if ($response->is_success) {
-        #get the valign-value:
-        return($response->headers->{'vertical-align'});}
-    else {
-        return(0); #if (error) than continue without valign
+    my ($esc_texstring)=@_;
+    my $valign = 0;
+    my $lonhost = $Apache::lonnet::perlvar{'lonHostID'};
+    my $hostname = &Apache::lonnet::hostname($lonhost);
+    my $protocol = $Apache::lonnet::protocol{$lonhost};
+    my $path = '/cgi-bin/mimetex.cgi?'.$esc_texstring;
+    my $socket;
+    &Apache::lonxml::start_alarm();
+    if ($protocol eq 'https') {
+        $socket = IO::Socket::SSL->new(PeerAddr => $hostname,
+                                       PeerPort => 'https(443)',
+                                       Proto    => 'tcp');
+    } else {
+        $socket = IO::Socket::INET->new(PeerAddr => $hostname,
+                                        PeerPort => 'http(80)',
+                                        Proto    => 'tcp');
+    }
+    if ($socket) {
+        my $headreq = "HEAD $path HTTP/1.0 User-Agent: Mozilla/5.0 \r\n\r\n";
+        print $socket $headreq;
+        while (<$socket>) {
+            if (/Vertical\-Align\:\s*?([\-\d]+)/) {
+                $valign = $1;
+            }
+        }
+        if ($protocol eq 'https') {
+            $socket->close(SSL_no_shutdown => 1,
+                           SSL_ctx_free => 1);
+        } else {
+            $socket->close();
+        }
     }
+    &Apache::lonxml::end_alarm();
+    return $valign;
 }
 
 sub mimetex_converted {
@@ -266,8 +289,9 @@
     if ($displaystyle) {
 	$$texstring='\\displaystyle \\Large '.$$texstring;
     }
-
-   my $result='<img src="/cgi-bin/mimetex.cgi?'.&escape($$texstring).'" style="vertical-align:'.&mimetex_valign($$texstring).'px" alt="$'.$$texstring.'$" />';
+    my $esc_texstring = &uri_escape($$texstring);
+    my $valign = &mimetex_valign($esc_texstring);
+    my $result='<img src="/cgi-bin/mimetex.cgi?'.$esc_texstring.'" style="vertical-align:'.$valign.'px" alt="$'.$$texstring.'$" />';
     if ($displaystyle) {
 	$result='<center>'.$result.'</center>';
     }