gitweb/cache.pm

   1 # gitweb - simple web interface to track changes in git repositories
   2 #
   3 # (C) 2006, John 'Warthog9' Hawley <warthog19@eaglescrag.net>
   4 #
   5 # This program is licensed under the GPLv2
   6
   7 #
   8 # Gitweb caching engine
   9 #
  10
  11 #package gitweb::cache;
  12 #use strict;
  13 #use warnings;
  14
  15 #my $VERSION = "0.00";
  16
  17 sub cache_fetch {
  18         my ($action) = @_;
  19         my $cacheTime = 0;
  20
  21         # Deal with cache being disabled
  22         if( $cache_enable == 0 ){
  23                 undef $backgroundCache;
  24                 $fullhashpath = \$nocachedata;
  25                 $fullhashbinpath = \$nocachedatabin;
  26         }elsif( $cache_enable == 1 ){
  27                 #obvious we are using file based caching
  28
  29                 #print "Action: $action\n";
  30                 if(! -d $cachedir){
  31                         print "*** Warning ***: Caching enabled but cache directory does not exsist.  ($cachedir)\n";
  32                         mkdir ("cache", 0665) || die "Cannot create cache dir - you will need to manually create";
  33                         print "Cache directory created successfully\n";
  34                 }
  35
  36                 #our $local_url =  "". $ENV{'HTTP_HOST'} ." + ". $ENV{'PATH_INFO'} ." + ". $ENV{'QUERY_STRING'} ."\n";
  37                 #print "URL: $local_url\n";
  38                 our $full_url = "$my_url?". $ENV{'QUERY_STRING'};
  39                 our $urlhash = md5_hex($full_url);
  40                 our $fullhashdir = "$cachedir/". substr( $urlhash, 0, 2) ."/";
  41
  42                 #if( $] < 5.010000 ) {
  43                         eval { mkpath( $fullhashdir, 0777 ) };
  44                         if ($@) {
  45                                 die_error(500, "Internal Server Error", "Could not create cache directory: $@");
  46                         }
  47                 #} else {
  48                 #       my $numdirs = make_path( $fullhashdir, { mode => 0777, error => \my $mkdirerr, } ); # This is only used with the newer File::Path
  49                 #       if( @$mkdirerr ){
  50                 #               my $mkdirerrmsg = "";
  51                 #               for my $diag (@$mkdirerr) {
  52                 #                       my ($file, $message) = %$diag;
  53                 #                       if($file eq '' ){
  54                 #                               $mkdirerrmsg .= "general error: $message\n";
  55                 #                       }else{
  56                 #                               $mkdirerrmsg .= "problem unlinking $file: $message\n";
  57                 #                       }
  58                 #               }
  59                 #               die_error(500, "Internal Server Error", "Could not create cache directory | $mkdirerrmsg");
  60                 #       }
  61                 #} # End figuring out File::Path usage
  62                 $fullhashpath = "$fullhashdir/". substr( $urlhash, 2 );
  63                 $fullhashbinpath = "$fullhashpath.bin";
  64         } # done dealing with cache enabled / disabled
  65
  66         if(! -e "$fullhashpath" ){
  67                 if( ! $cache_enable || ! $cacheDoFork || ! defined(my $childPid = fork()) ){
  68                         cacheUpdate($action,0);
  69                         cacheDisplay($action);
  70                 } elsif ( $childPid == 0 ){
  71                         #run the updater
  72                         cacheUpdate($action,1);
  73                 }else{
  74                         cacheWaitForUpdate($action);
  75                 }
  76         }else{
  77                 #if cache is out dated, update
  78                 #else displayCache();
  79                 open(cacheFile, '<', "$fullhashpath");
  80                 stat(cacheFile);
  81                 close(cacheFile);
  82                 $cacheTime = get_loadavg() * 60;
  83                 if( $cacheTime > $maxCacheTime ){
  84                         $cacheTime = $maxCacheTime;
  85                 }
  86                 if( $cacheTime < $minCacheTime ){
  87                         $cacheTime = $minCacheTime;
  88                 }
  89                 if( (stat(_))[9] < (time - $cacheTime) ){
  90                         if( ! $cacheDoFork || ! defined(my $childPid = fork()) ){
  91                                 cacheUpdate($action,0);
  92                                 cacheDisplay($action);
  93                         } elsif ( $childPid == 0 ){
  94                                 #run the updater
  95                                 #print "Running updater\n";
  96                                 cacheUpdate($action,1);
  97                         }else{
  98                                 #print "Waiting for update\n";
  99                                 cacheWaitForUpdate($action);
 100                         }
 101                 } else {
 102                         cacheDisplay($action);
 103                 }
 104
 105
 106         }
 107
 108         #
 109         # If all of the caching failes - lets go ahead and press on without it and fall back to 'default'
 110         # non-caching behavior.  This is the softest of the failure conditions.
 111         #
 112         #$actions{$action}->();
 113 }
 114
 115 sub cacheUpdate {
 116         my ($action,$areForked) = @_;
 117         my $lockingStatus;
 118         my $fileData = "";
 119
 120         if($backgroundCache){
 121                 open(cacheFileBG, '>:utf8', "$fullhashpath.bg");
 122                 my $lockStatBG = flock(cacheFileBG,LOCK_EX|LOCK_NB);
 123
 124                 $lockStatus = $lockStatBG;
 125         }else{
 126                 open(cacheFile, '>:utf8', "$fullhashpath") if ($cache_enable > 0);
 127                 open(cacheFile, '>:utf8', \$fullhashpath) if ($cache_enable == 0);
 128                 my $lockStat = flock(cacheFile,LOCK_EX|LOCK_NB);
 129
 130                 $lockStatus = $lockStat;
 131         }
 132         #print "lock status: $lockStat\n";
 133
 134
 135         if ($cache_enable != 0 && ! $lockStatus ){
 136                 if ( $areForked ){
 137                         exit(0);
 138                 }else{
 139                         return;
 140                 }
 141         }
 142
 143
 144         $fileData = "". $actions{$action}->() ."";
 145
 146         if($backgroundCache){
 147                 open(cacheFile, '>:utf8', "$fullhashpath");
 148                 $lockStat = flock(cacheFile,LOCK_EX);
 149
 150                 if (! $lockStat ){
 151                         if ( $areForked ){
 152                                 exit(0);
 153                         }else{
 154                                 return;
 155                         }
 156                 }
 157         }
 158
 159         print cacheFile "$fileData";
 160
 161         flock(cacheFile,LOCK_UN);
 162         close(cacheFile);
 163
 164         if($backgroundCache){
 165                 flock(cacheFileBG,LOCK_UN);
 166                 close(cacheFileBG);
 167         }
 168
 169         if ( $areForked ){
 170                 exit(0);
 171         } else {
 172                 return;
 173         }
 174 }
 175
 176
 177 sub cacheWaitForUpdate {
 178         my ($action) = @_;
 179         my $x = 0;
 180         my $max = 10;
 181         my $lockStat = 0;
 182
 183         if( $backgroundCache ){
 184                 if( -e "$fullhashpath" ){
 185                         open(cacheFile, '<:utf8', "$fullhashpath") if ($cache_enable > 0);
 186                         open(cacheFile, '<:utf8', \$fullhashpath) if ($cache_enable == 0);
 187                         $lockStat = flock(cacheFile,LOCK_SH|LOCK_NB);
 188                         stat(cacheFile);
 189                         close(cacheFile);
 190
 191                         if( $lockStat && ( (stat(_))[9] > (time - $maxCacheLife) ) ){
 192                                 cacheDisplay($action);
 193                                 return;
 194                         }
 195                 }
 196         }
 197
 198         #our $headerRefresh = 1;
 199         #print git_header_html();
 200
 201         if(
 202                 $action eq "atom"
 203                 ||
 204                 $action eq "rss"
 205                 ||
 206                 $action eq "opml"
 207         ){
 208                 do {
 209                         sleep 2 if $x > 0;
 210                         open(cacheFile, '<:utf8', "$fullhashpath") if ($cache_enable > 0);
 211                         open(cacheFile, '<:utf8', \$fullhashpath) if ($cache_enable == 0);
 212                         $lockStat = flock(cacheFile,LOCK_SH|LOCK_NB);
 213                         close(cacheFile);
 214                         $x++;
 215                         $combinedLockStat = $lockStat;
 216                 } while ((! $combinedLockStat) && ($x < $max));
 217
 218                 if( $x != $max ){
 219                         cacheDisplay($action);
 220                 }
 221                 return;
 222         }
 223
 224         $| = 1;
 225
 226         print $::cgi->header(
 227                                 -type=>'text/html',
 228                                 -charset => 'utf-8',
 229                                 -status=> 200,
 230                                 -expires => 'now',
 231                                 # HTTP/1.0
 232                                 -Pragma => 'no-cache',
 233                                 # HTTP/1.1
 234                                 -Cache_Control => join(
 235                                                         ', ',
 236                                                         qw(
 237                                                                 private
 238                                                                 no-cache
 239                                                                 no-store
 240                                                                 must-revalidate
 241                                                                 max-age=0
 242                                                                 pre-check=0
 243                                                                 post-check=0
 244                                                         )
 245                                                 )
 246                                 );
 247
 248         print <<EOF;
 249 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www/w3.porg/TR/html4/strict.dtd">
 250 <!-- git web interface version $version, (C) 2005-2006, Kay Sievers <kay.sievers\@vrfy.org>, Christian Gierke -->
 251 <!-- git core binaries version $git_version -->
 252 <head>
 253 <meta http-equiv="content-type" content="$content_type; charset=utf-8"/>
 254 <meta name="generator" content="gitweb/$version git/$git_version"/>
 255 <meta name="robots" content="index, nofollow"/>
 256 <meta http-equiv="refresh" content="0"/>
 257 <title>$title</title>
 258 </head>
 259 <body>
 260 EOF
 261
 262         print "Generating..";
 263         do {
 264                 print ".";
 265                 sleep 2 if $x > 0;
 266                 open(cacheFile, '<:utf8', "$fullhashpath") if ($cache_enable > 0);
 267                 open(cacheFile, '<:utf8', \$fullhashpath) if ($cache_enable == 0);
 268                 $lockStat = flock(cacheFile,LOCK_SH|LOCK_NB);
 269                 close(cacheFile);
 270                 #$lockStatbg = flock(cacheFilebg,LOCK_SH|LOCK_NB) if $backgroundCache;
 271                 #print "Lock State: $lockStat\n";
 272                 #if( ! $lockStat ){
 273                 #       print "Error: ". $! ."\n";
 274                 #}
 275                 $x++;
 276                 $combinedLockStat = $lockStat;
 277                 #$combinedLockStat = $lockStat & $lockStatbg if $backgroundCache;
 278         } while ((! $combinedLockStat) && ($x < $max));
 279         #} while ($x < $max);
 280         #close(cacheFile);
 281         #close(cacheFilebg) if $backgroundCache;
 282         #print git_footer_html();
 283         print <<EOF;
 284 </body>
 285 </html>
 286 EOF
 287         #exit(0);
 288         return;
 289         #cacheDisplay();
 290 }
 291
 292 sub cacheDisplay {
 293         my ($action) = @_;
 294         open(cacheFile, '<:utf8', "$fullhashpath") if ($cache_enable > 0);
 295         open(cacheFile, '<:utf8', \$fullhashpath) if ($cache_enable == 0);
 296         $lockStat = flock(cacheFile,LOCK_SH|LOCK_NB);
 297         if ($cache_enable != 0 && ! $lockStat ){
 298                 close(cacheFile);
 299                 cacheWaitForUpdate($action);
 300         }
 301
 302         while( <cacheFile> ){
 303                 print $_;
 304         }
 305         if(
 306                 $action eq "snapshot"
 307                 ||
 308                 $action eq "blob_plain"
 309         ){
 310                 open(cacheFileBin, '<', "$fullhashbinpath");
 311                 binmode STDOUT, ':raw';
 312                 print <cacheFileBin>;
 313                 binmode STDOUT, ':utf8'; # as set at the beginning of gitweb.cgi
 314                 close(cacheFileBin);
 315         }
 316         close(cacheFile);
 317 }
 318
 319 #1;