File:  [LON-CAPA] / loncom / lonsql
Revision 1.72: download - view: text, annotated - select for diffs
Tue Feb 7 22:30:31 2006 UTC (18 years, 2 months ago) by albertel
Branches: MAIN
CVS tags: HEAD
- &reply() needs to connect to the correct location

    1: #!/usr/bin/perl
    2: 
    3: # The LearningOnline Network
    4: # lonsql - LON TCP-MySQL-Server Daemon for handling database requests.
    5: #
    6: # $Id: lonsql,v 1.72 2006/02/07 22:30:31 albertel Exp $
    7: #
    8: # Copyright Michigan State University Board of Trustees
    9: #
   10: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
   11: #
   12: # LON-CAPA is free software; you can redistribute it and/or modify
   13: # it under the terms of the GNU General Public License as published by
   14: # the Free Software Foundation; either version 2 of the License, or
   15: # (at your option) any later version.
   16: #
   17: # LON-CAPA is distributed in the hope that it will be useful,
   18: # but WITHOUT ANY WARRANTY; without even the implied warranty of
   19: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   20: # GNU General Public License for more details.
   21: #
   22: # You should have received a copy of the GNU General Public License
   23: # along with LON-CAPA; if not, write to the Free Software
   24: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   25: #
   26: # /home/httpd/html/adm/gpl.txt
   27: #
   28: # http://www.lon-capa.org/
   29: #
   30: 
   31: =pod
   32: 
   33: =head1 NAME
   34: 
   35: lonsql - LON TCP-MySQL-Server Daemon for handling database requests.
   36: 
   37: =head1 SYNOPSIS
   38: 
   39: This script should be run as user=www.  
   40: Note that a lonsql.pid file contains the pid of the parent process.
   41: 
   42: =head1 OVERVIEW
   43: 
   44: =head2 Purpose within LON-CAPA
   45: 
   46: LON-CAPA is meant to distribute A LOT of educational content to A LOT
   47: of people. It is ineffective to directly rely on contents within the
   48: ext2 filesystem to be speedily scanned for on-the-fly searches of
   49: content descriptions. (Simply put, it takes a cumbersome amount of
   50: time to open, read, analyze, and close thousands of files.)
   51: 
   52: The solution is to index various data fields that are descriptive of
   53: the educational resources on a LON-CAPA server machine in a
   54: database. Descriptive data fields are referred to as "metadata". The
   55: question then arises as to how this metadata is handled in terms of
   56: the rest of the LON-CAPA network without burdening client and daemon
   57: processes.
   58: 
   59: The obvious solution, using lonc to send a query to a lond process,
   60: doesn't work so well in general as you can see in the following
   61: example:
   62: 
   63:     lonc= loncapa client process    A-lonc= a lonc process on Server A
   64:     lond= loncapa daemon process
   65: 
   66:                  database command
   67:     A-lonc  --------TCP/IP----------------> B-lond
   68: 
   69: The problem emerges that A-lonc and B-lond are kept waiting for the
   70: MySQL server to "do its stuff", or in other words, perform the
   71: conceivably sophisticated, data-intensive, time-sucking database
   72: transaction.  By tying up a lonc and lond process, this significantly
   73: cripples the capabilities of LON-CAPA servers.
   74: 
   75: The solution is to offload the work onto another process, and use
   76: lonc and lond just for requests and notifications of completed
   77: processing:
   78: 
   79:                 database command
   80: 
   81:   A-lonc  ---------TCP/IP-----------------> B-lond =====> B-lonsql
   82:          <---------------------------------/                |
   83:            "ok, I'll get back to you..."                    |
   84:                                                             |
   85:                                                             /
   86:   A-lond  <-------------------------------  B-lonc   <======
   87:            "Guess what? I have the result!"
   88: 
   89: Of course, depending on success or failure, the messages may vary, but
   90: the principle remains the same where a separate pool of children
   91: processes (lonsql's) handle the MySQL database manipulations.
   92: 
   93: Thus, lonc and lond spend effectively no time waiting on results from
   94: the database.
   95: 
   96: =head1 Internals
   97: 
   98: =over 4
   99: 
  100: =cut
  101: 
  102: use strict;
  103: 
  104: use lib '/home/httpd/lib/perl/';
  105: use LONCAPA::Configuration;
  106: use LONCAPA::lonmetadata();
  107: 
  108: use IO::Socket;
  109: use Symbol;
  110: use POSIX;
  111: use IO::Select;
  112: use IO::File;
  113: use Socket;
  114: use Fcntl;
  115: use Tie::RefHash;
  116: use DBI;
  117: use File::Find;
  118: use localenroll;
  119: 
  120: ########################################################
  121: ########################################################
  122: 
  123: =pod
  124: 
  125: =item Global Variables
  126: 
  127: =over 4
  128: 
  129: =item dbh
  130: 
  131: =back
  132: 
  133: =cut
  134: 
  135: ########################################################
  136: ########################################################
  137: my $dbh;
  138: 
  139: ########################################################
  140: ########################################################
  141: 
  142: =pod 
  143: 
  144: =item Variables required for forking
  145: 
  146: =over 4
  147: 
  148: =item $MAX_CLIENTS_PER_CHILD
  149: 
  150: The number of clients each child should process.
  151: 
  152: =item %children 
  153: 
  154: The keys to %children  are the current child process IDs
  155: 
  156: =item $children
  157: 
  158: The current number of children
  159: 
  160: =back
  161: 
  162: =cut 
  163: 
  164: ########################################################
  165: ########################################################
  166: my $MAX_CLIENTS_PER_CHILD  = 5;   # number of clients each child should process
  167: my %children               = ();  # keys are current child process IDs
  168: my $children               = 0;   # current number of children
  169:                                
  170: ###################################################################
  171: ###################################################################
  172: 
  173: =pod
  174: 
  175: =item Main body of code.
  176: 
  177: =over 4
  178: 
  179: =item Read data from loncapa_apache.conf and loncapa.conf.
  180: 
  181: =item Ensure we can access the database.
  182: 
  183: =item Determine if there are other instances of lonsql running.
  184: 
  185: =item Read the hosts file.
  186: 
  187: =item Create a socket for lonsql.
  188: 
  189: =item Fork once and dissociate from parent.
  190: 
  191: =item Write PID to disk.
  192: 
  193: =item Prefork children and maintain the population of children.
  194: 
  195: =back
  196: 
  197: =cut
  198: 
  199: ###################################################################
  200: ###################################################################
  201: my $childmaxattempts=10;
  202: my $run =0;              # running counter to generate the query-id
  203: #
  204: # Read loncapa_apache.conf and loncapa.conf
  205: #
  206: my $perlvarref=LONCAPA::Configuration::read_conf('loncapa.conf');
  207: my %perlvar=%{$perlvarref};
  208: #
  209: # Write the /home/www/.my.cnf file 
  210: my $conf_file = '/home/www/.my.cnf';
  211: if (! -e $conf_file) {
  212:     if (open MYCNF, ">$conf_file") {
  213:         print MYCNF <<"ENDMYCNF";
  214: [client]
  215: user=www
  216: password=$perlvar{'lonSqlAccess'}
  217: ENDMYCNF
  218:         close MYCNF;
  219:     } else {
  220:         warn "Unable to write $conf_file, continuing";
  221:     }
  222: }
  223: 
  224: 
  225: #
  226: # Make sure that database can be accessed
  227: #
  228: my $dbh;
  229: unless ($dbh = DBI->connect("DBI:mysql:loncapa","www",
  230:                             $perlvar{'lonSqlAccess'},
  231:                             { RaiseError =>0,PrintError=>0})) { 
  232:     print "Cannot connect to database!\n";
  233:     my $emailto="$perlvar{'lonAdmEMail'},$perlvar{'lonSysEMail'}";
  234:     my $subj="LON: $perlvar{'lonHostID'} Cannot connect to database!";
  235:     system("echo 'Cannot connect to MySQL database!' |".
  236:            " mailto $emailto -s '$subj' > /dev/null");
  237: 
  238:     open(SMP,'>/home/httpd/html/lon-status/mysql.txt');
  239:     print SMP 'time='.time.'&mysql=defunct'."\n";
  240:     close(SMP);
  241: 
  242:     exit 1;
  243: } else {
  244:     unlink('/home/httpd/html/lon-status/mysql.txt');
  245:     $dbh->disconnect;
  246: }
  247: 
  248: #
  249: # Check if other instance running
  250: #
  251: my $pidfile="$perlvar{'lonDaemons'}/logs/lonsql.pid";
  252: if (-e $pidfile) {
  253:    my $lfh=IO::File->new("$pidfile");
  254:    my $pide=<$lfh>;
  255:    chomp($pide);
  256:    if (kill 0 => $pide) { die "already running"; }
  257: }
  258: 
  259: #
  260: # Read hosts file
  261: #
  262: my $thisserver;
  263: my %hostname;
  264: my $PREFORK=4; # number of children to maintain, at least four spare
  265: open (CONFIG,"$perlvar{'lonTabDir'}/hosts.tab") || die "Can't read host file";
  266: while (my $configline=<CONFIG>) {
  267:     my ($id,$domain,$role,$name)=split(/:/,$configline);
  268:     $name=~s/\s//g;
  269:     $thisserver=$name if ($id eq $perlvar{'lonHostID'});
  270:     $hostname{$id}=$name;
  271:     #$PREFORK++;
  272: }
  273: close(CONFIG);
  274: #
  275: #$PREFORK=int($PREFORK/4);
  276: 
  277: #
  278: # Create a socket to talk to lond
  279: #
  280: my $unixsock = "mysqlsock";
  281: my $localfile="$perlvar{'lonSockDir'}/$unixsock";
  282: my $server;
  283: unlink ($localfile);
  284: unless ($server=IO::Socket::UNIX->new(Local    =>"$localfile",
  285:                                       Type    => SOCK_STREAM,
  286:                                       Listen => 10)) {
  287:     print "in socket error:$@\n";
  288: }
  289: 
  290: #
  291: # Fork once and dissociate
  292: #
  293: my $fpid=fork;
  294: exit if $fpid;
  295: die "Couldn't fork: $!" unless defined ($fpid);
  296: POSIX::setsid() or die "Can't start new session: $!";
  297: 
  298: #
  299: # Write our PID on disk
  300: my $execdir=$perlvar{'lonDaemons'};
  301: open (PIDSAVE,">$execdir/logs/lonsql.pid");
  302: print PIDSAVE "$$\n";
  303: close(PIDSAVE);
  304: &logthis("<font color='red'>CRITICAL: ---------- Starting ----------</font>");
  305: 
  306: #
  307: # Ignore signals generated during initial startup
  308: $SIG{HUP}=$SIG{USR1}='IGNORE';
  309: # Now we are on our own    
  310: #    Fork off our children.
  311: for (1 .. $PREFORK) {
  312:     make_new_child();
  313: }
  314: 
  315: #
  316: # Install signal handlers.
  317: $SIG{CHLD} = \&REAPER;
  318: $SIG{INT}  = $SIG{TERM} = \&HUNTSMAN;
  319: $SIG{HUP}  = \&HUPSMAN;
  320: 
  321: #
  322: # And maintain the population.
  323: while (1) {
  324:     sleep;                          # wait for a signal (i.e., child's death)
  325:     for (my $i = $children; $i < $PREFORK; $i++) {
  326:         make_new_child();           # top up the child pool
  327:     }
  328: }
  329: 
  330: ########################################################
  331: ########################################################
  332: 
  333: =pod
  334: 
  335: =item &make_new_child
  336: 
  337: Inputs: None
  338: 
  339: Returns: None
  340: 
  341: =cut
  342: 
  343: ########################################################
  344: ########################################################
  345: sub make_new_child {
  346:     my $pid;
  347:     my $sigset;
  348:     #
  349:     # block signal for fork
  350:     $sigset = POSIX::SigSet->new(SIGINT);
  351:     sigprocmask(SIG_BLOCK, $sigset)
  352:         or die "Can't block SIGINT for fork: $!\n";
  353:     #
  354:     die "fork: $!" unless defined ($pid = fork);
  355:     #
  356:     if ($pid) {
  357:         # Parent records the child's birth and returns.
  358:         sigprocmask(SIG_UNBLOCK, $sigset)
  359:             or die "Can't unblock SIGINT for fork: $!\n";
  360:         $children{$pid} = 1;
  361:         $children++;
  362:         return;
  363:     } else {
  364:         # Child can *not* return from this subroutine.
  365:         $SIG{INT} = 'DEFAULT';      # make SIGINT kill us as it did before
  366:         # unblock signals
  367:         sigprocmask(SIG_UNBLOCK, $sigset)
  368:             or die "Can't unblock SIGINT for fork: $!\n";
  369:         #open database handle
  370: 	# making dbh global to avoid garbage collector
  371: 	unless ($dbh = DBI->connect("DBI:mysql:loncapa","www",
  372:                                     $perlvar{'lonSqlAccess'},
  373:                                     { RaiseError =>0,PrintError=>0})) { 
  374:             sleep(10+int(rand(20)));
  375:             &logthis("<font color='blue'>WARNING: Couldn't connect to database".
  376:                      ": $@</font>");
  377:                      #  "($st secs): $@</font>");
  378:             print "database handle error\n";
  379:             exit;
  380:         }
  381: 	# make sure that a database disconnection occurs with 
  382:         # ending kill signals
  383: 	$SIG{TERM}=$SIG{INT}=$SIG{QUIT}=$SIG{__DIE__}=\&DISCONNECT;
  384:         # handle connections until we've reached $MAX_CLIENTS_PER_CHILD
  385:         for (my $i=0; $i < $MAX_CLIENTS_PER_CHILD; $i++) {
  386:             my $client = $server->accept() or last;
  387:             # do something with the connection
  388: 	    $run = $run+1;
  389: 	    my $userinput = <$client>;
  390: 	    chomp($userinput);
  391:             #
  392: 	    my ($conserver,$query,
  393: 		$arg1,$arg2,$arg3)=split(/&/,$userinput);
  394: 	    my $query=unescape($query);
  395:             #
  396:             #send query id which is pid_unixdatetime_runningcounter
  397: 	    my $queryid = $thisserver;
  398: 	    $queryid .="_".($$)."_";
  399: 	    $queryid .= time."_";
  400: 	    $queryid .= $run;
  401: 	    print $client "$queryid\n";
  402: 	    #
  403: 	    # &logthis("QUERY: $query - $arg1 - $arg2 - $arg3");
  404: 	    sleep 1;
  405:             #
  406:             my $result='';
  407:             #
  408:             # At this point, query is received, query-ID assigned and sent 
  409:             # back, $query eq 'logquery' will mean that this is a query 
  410:             # against log-files
  411:             if (($query eq 'userlog') || ($query eq 'courselog')) {
  412:                 # beginning of log query
  413:                 my $udom    = &unescape($arg1);
  414:                 my $uname   = &unescape($arg2);
  415:                 my $command = &unescape($arg3);
  416:                 my $path    = &propath($udom,$uname);
  417:                 if (-e "$path/activity.log") {
  418:                     if ($query eq 'userlog') {
  419:                         $result=&userlog($path,$command);
  420:                     } else {
  421:                         $result=&courselog($path,$command);
  422:                     }
  423:                 } else {
  424:                     &logthis('Unable to do log query: '.$uname.'@'.$udom);
  425:                     $result='no_such_file';
  426:                 }
  427:                 # end of log query
  428:             } elsif (($query eq 'fetchenrollment') || 
  429: 		     ($query eq 'institutionalphotos')) {
  430:                 # retrieve institutional class lists
  431:                 my $dom = &unescape($arg1);
  432:                 my %affiliates = ();
  433:                 my %replies = ();
  434:                 my $locresult = '';
  435:                 my $querystr = &unescape($arg3);
  436:                 foreach (split/%%/,$querystr) {
  437:                     if (/^([^=]+)=([^=]+)$/) {
  438:                         @{$affiliates{$1}} = split/,/,$2;
  439:                     }
  440:                 }
  441:                 if ($query eq 'fetchenrollment') { 
  442:                     $locresult = &localenroll::fetch_enrollment($dom,\%affiliates,\%replies);
  443:                 } elsif ($query eq 'institutionalphotos') {
  444:                     my $crs = &unescape($arg2);
  445:                     $locresult = &localenroll::institutional_photos($dom,$crs,\%affiliates,\%replies,'update');
  446:                 }
  447:                 $result = &escape($locresult.':');
  448:                 if ($locresult) {
  449:                     $result .= &escape(join(':',map{$_.'='.$replies{$_}} keys %replies));
  450:                 }
  451:             } elsif ($query eq 'prepare activity log') {
  452:                 my ($cid,$domain) = map {&unescape($_);} ($arg1,$arg2);
  453:                 &logthis('preparing activity log tables for '.$cid);
  454:                 my $command = 
  455:                     qq{$perlvar{'lonDaemons'}/parse_activity_log.pl -course=$cid -domain=$domain};
  456:                 system($command);
  457:                 &logthis($command);
  458:                 my $returnvalue = $?>>8;
  459:                 if ($returnvalue) {
  460:                     $result = 'error: parse_activity_log.pl returned '.
  461:                         $returnvalue;
  462:                 } else {
  463:                     $result = 'success';
  464:                 }
  465:             } else {
  466:                 # Do an sql query
  467:                 $result = &do_sql_query($query,$arg1,$arg2);
  468:             }
  469:             # result does not need to be escaped because it has already been
  470:             # escaped.
  471:             #$result=&escape($result);
  472:             &reply("queryreply:$queryid:$result",$conserver);
  473:         }
  474:         # tidy up gracefully and finish
  475:         #
  476:         # close the database handle
  477: 	$dbh->disconnect
  478:             or &logthis("<font color='blue'>WARNING: Couldn't disconnect".
  479:                         " from database  $DBI::errstr : $@</font>");
  480:         # this exit is VERY important, otherwise the child will become
  481:         # a producer of more and more children, forking yourself into
  482:         # process death.
  483:         exit;
  484:     }
  485: }
  486: 
  487: ########################################################
  488: ########################################################
  489: 
  490: =pod
  491: 
  492: =item &do_sql_query
  493: 
  494: Runs an sql metadata table query.
  495: 
  496: Inputs: $query, $custom, $customshow
  497: 
  498: Returns: A string containing escaped results.
  499: 
  500: =cut
  501: 
  502: ########################################################
  503: ########################################################
  504: {
  505:     my @metalist;
  506: 
  507: sub process_file {
  508:     if ( -e $_ &&  # file exists
  509:          -f $_ &&  # and is a normal file
  510:          /\.meta$/ &&  # ends in meta
  511:          ! /^.+\.\d+\.[^\.]+\.meta$/  # is not a previous version
  512:          ) {
  513:         push(@metalist,$File::Find::name);
  514:     }
  515: }
  516: 
  517: sub do_sql_query {
  518:     my ($query,$custom,$customshow) = @_;
  519: #    &logthis('doing query '.$query);
  520:     $custom     = &unescape($custom);
  521:     $customshow = &unescape($customshow);
  522:     #
  523:     @metalist = ();
  524:     #
  525:     my $result = '';
  526:     my @results = ();
  527:     my @files;
  528:     my $subsetflag=0;
  529:     #
  530:     if ($query) {
  531:         #prepare and execute the query
  532:         my $sth = $dbh->prepare($query);
  533:         unless ($sth->execute()) {
  534:             &logthis('<font color="blue">'.
  535:                      'WARNING: Could not retrieve from database:'.
  536:                      $sth->errstr().'</font>');
  537:         } else {
  538:             my $aref=$sth->fetchall_arrayref;
  539:             foreach my $row (@$aref) {
  540:                 push @files,@{$row}[3] if ($custom or $customshow);
  541:                 my @b=map { &escape($_); } @$row;
  542:                 push @results,join(",", @b);
  543:                 # Build up the @files array with the LON-CAPA urls 
  544:                 # of the resources.
  545:             }
  546:         }
  547:     }
  548:     # do custom metadata searching here and build into result
  549:     return join("&",@results) if (! ($custom or $customshow));
  550:     # Only get here if there is a custom query or custom show request
  551:     &logthis("Doing custom query for $custom");
  552:     if ($query) {
  553:         @metalist=map {
  554:             $perlvar{'lonDocRoot'}.$_.'.meta';
  555:         } @files;
  556:     } else {
  557:         my $dir = "$perlvar{'lonDocRoot'}/res/$perlvar{'lonDefDomain'}";
  558:         @metalist=(); 
  559:         opendir(RESOURCES,$dir);
  560:         my @homeusers=grep {
  561:             &ishome($dir.'/'.$_);
  562:         } grep {!/^\.\.?$/} readdir(RESOURCES);
  563:         closedir RESOURCES;
  564:         # Define the
  565:         foreach my $user (@homeusers) {
  566:             find (\&process_file,$dir.'/'.$user);
  567:         }
  568:     } 
  569:     # if file is indicated in sql database and
  570:     #     not part of sql-relevant query, do not pattern match.
  571:     #
  572:     # if file is not in sql database, output error.
  573:     #
  574:     # if file is indicated in sql database and is
  575:     #     part of query result list, then do the pattern match.
  576:     my $customresult='';
  577:     my @results;
  578:     foreach my $metafile (@metalist) {
  579:         my $fh=IO::File->new($metafile);
  580:         my @lines=<$fh>;
  581:         my $stuff=join('',@lines);
  582:         if ($stuff=~/$custom/s) {
  583:             foreach my $f ('abstract','author','copyright',
  584:                            'creationdate','keywords','language',
  585:                            'lastrevisiondate','mime','notes',
  586:                            'owner','subject','title') {
  587:                 $stuff=~s/\n?\<$f[^\>]*\>.*?<\/$f[^\>]*\>\n?//s;
  588:             }
  589:             my $mfile=$metafile; 
  590:             my $docroot=$perlvar{'lonDocRoot'};
  591:             $mfile=~s/^$docroot//;
  592:             $mfile=~s/\.meta$//;
  593:             unless ($query) {
  594:                 my $q2="SELECT * FROM metadata WHERE url ".
  595:                     " LIKE BINARY '?'";
  596:                 my $sth = $dbh->prepare($q2);
  597:                 $sth->execute($mfile);
  598:                 my $aref=$sth->fetchall_arrayref;
  599:                 foreach my $a (@$aref) {
  600:                     my @b=map { &escape($_)} @$a;
  601:                     push @results,join(",", @b);
  602:                 }
  603:             }
  604:             # &logthis("found: $stuff");
  605:             $customresult.='&custom='.&escape($mfile).','.
  606:                 escape($stuff);
  607:         }
  608:     }
  609:     $result=join("&",@results) unless $query;
  610:     $result.=$customresult;
  611:     #
  612:     return $result;
  613: } # End of &do_sql_query
  614: 
  615: } # End of scoping curly braces for &process_file and &do_sql_query
  616: ########################################################
  617: ########################################################
  618: 
  619: =pod
  620: 
  621: =item &logthis
  622: 
  623: Inputs: $message, the message to log
  624: 
  625: Returns: nothing
  626: 
  627: Writes $message to the logfile.
  628: 
  629: =cut
  630: 
  631: ########################################################
  632: ########################################################
  633: sub logthis {
  634:     my $message=shift;
  635:     my $execdir=$perlvar{'lonDaemons'};
  636:     my $fh=IO::File->new(">>$execdir/logs/lonsql.log");
  637:     my $now=time;
  638:     my $local=localtime($now);
  639:     print $fh "$local ($$): $message\n";
  640: }
  641: 
  642: # -------------------------------------------------- Non-critical communication
  643: 
  644: ########################################################
  645: ########################################################
  646: 
  647: =pod
  648: 
  649: =item &subreply
  650: 
  651: Sends a command to a server.  Called only by &reply.
  652: 
  653: Inputs: $cmd,$server
  654: 
  655: Returns: The results of the message or 'con_lost' on error.
  656: 
  657: =cut
  658: 
  659: ########################################################
  660: ########################################################
  661: sub subreply {
  662:     my ($cmd,$server)=@_;
  663:     my $peerfile="$perlvar{'lonSockDir'}/".$hostname{$server};
  664:     my $sclient=IO::Socket::UNIX->new(Peer    =>"$peerfile",
  665:                                       Type    => SOCK_STREAM,
  666:                                       Timeout => 10)
  667:        or return "con_lost";
  668:     print $sclient "sethost:$server:$cmd\n";
  669:     my $answer=<$sclient>;
  670:     chomp($answer);
  671:     $answer="con_lost" if (!$answer);
  672:     return $answer;
  673: }
  674: 
  675: ########################################################
  676: ########################################################
  677: 
  678: =pod
  679: 
  680: =item &reply
  681: 
  682: Sends a command to a server.
  683: 
  684: Inputs: $cmd,$server
  685: 
  686: Returns: The results of the message or 'con_lost' on error.
  687: 
  688: =cut
  689: 
  690: ########################################################
  691: ########################################################
  692: sub reply {
  693:   my ($cmd,$server)=@_;
  694:   my $answer;
  695:   if ($server ne $perlvar{'lonHostID'}) { 
  696:     $answer=subreply($cmd,$server);
  697:     if ($answer eq 'con_lost') {
  698: 	$answer=subreply("ping",$server);
  699:         $answer=subreply($cmd,$server);
  700:     }
  701:   } else {
  702:     $answer='self_reply';
  703:     $answer=subreply($cmd,$server);
  704:   } 
  705:   return $answer;
  706: }
  707: 
  708: ########################################################
  709: ########################################################
  710: 
  711: =pod
  712: 
  713: =item &escape
  714: 
  715: Escape special characters in a string.
  716: 
  717: Inputs: string to escape
  718: 
  719: Returns: The input string with special characters escaped.
  720: 
  721: =cut
  722: 
  723: ########################################################
  724: ########################################################
  725: sub escape {
  726:     my $str=shift;
  727:     $str =~ s/(\W)/"%".unpack('H2',$1)/eg;
  728:     return $str;
  729: }
  730: 
  731: ########################################################
  732: ########################################################
  733: 
  734: =pod
  735: 
  736: =item &unescape
  737: 
  738: Unescape special characters in a string.
  739: 
  740: Inputs: string to unescape
  741: 
  742: Returns: The input string with special characters unescaped.
  743: 
  744: =cut
  745: 
  746: ########################################################
  747: ########################################################
  748: sub unescape {
  749:     my $str=shift;
  750:     $str =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
  751:     return $str;
  752: }
  753: 
  754: ########################################################
  755: ########################################################
  756: 
  757: =pod
  758: 
  759: =item &ishome
  760: 
  761: Determine if the current machine is the home server for a user.
  762: The determination is made by checking the filesystem for the users information.
  763: 
  764: Inputs: $author
  765: 
  766: Returns: 0 - this is not the authors home server, 1 - this is.
  767: 
  768: =cut
  769: 
  770: ########################################################
  771: ########################################################
  772: sub ishome {
  773:     my $author=shift;
  774:     $author=~s/\/home\/httpd\/html\/res\/([^\/]*)\/([^\/]*).*/$1\/$2/;
  775:     my ($udom,$uname)=split(/\//,$author);
  776:     my $proname=propath($udom,$uname);
  777:     if (-e $proname) {
  778: 	return 1;
  779:     } else {
  780:         return 0;
  781:     }
  782: }
  783: 
  784: ########################################################
  785: ########################################################
  786: 
  787: =pod
  788: 
  789: =item &propath
  790: 
  791: Inputs: user name, user domain
  792: 
  793: Returns: The full path to the users directory.
  794: 
  795: =cut
  796: 
  797: ########################################################
  798: ########################################################
  799: sub propath {
  800:     my ($udom,$uname)=@_;
  801:     $udom=~s/\W//g;
  802:     $uname=~s/\W//g;
  803:     my $subdir=$uname.'__';
  804:     $subdir =~ s/(.)(.)(.).*/$1\/$2\/$3/;
  805:     my $proname="$perlvar{'lonUsersDir'}/$udom/$subdir/$uname";
  806:     return $proname;
  807: } 
  808: 
  809: ########################################################
  810: ########################################################
  811: 
  812: =pod
  813: 
  814: =item &courselog
  815: 
  816: Inputs: $path, $command
  817: 
  818: Returns: unescaped string of values.
  819: 
  820: =cut
  821: 
  822: ########################################################
  823: ########################################################
  824: sub courselog {
  825:     my ($path,$command)=@_;
  826:     my %filters=();
  827:     foreach (split(/\:/,&unescape($command))) {
  828: 	my ($name,$value)=split(/\=/,$_);
  829:         $filters{$name}=$value;
  830:     }
  831:     my @results=();
  832:     open(IN,$path.'/activity.log') or return ('file_error');
  833:     while (my $line=<IN>) {
  834:         chomp($line);
  835:         my ($timestamp,$host,$log)=split(/\:/,$line);
  836: #
  837: # $log has the actual log entries; currently still escaped, and
  838: # %26(timestamp)%3a(url)%3a(user)%3a(domain)
  839: # then additionally
  840: # %3aPOST%3a(name)%3d(value)%3a(name)%3d(value)
  841: # or
  842: # %3aCSTORE%3a(name)%3d(value)%26(name)%3d(value)
  843: #
  844: # get delimiter between timestamped entries to be &&&
  845:         $log=~s/\%26(\d+)\%3a/\&\&\&$1\%3a/g;
  846: # now go over all log entries 
  847:         foreach (split(/\&\&\&/,&unescape($log))) {
  848: 	    my ($time,$res,$uname,$udom,$action,@values)=split(/\:/,$_);
  849:             my $values=&unescape(join(':',@values));
  850:             $values=~s/\&/\:/g;
  851:             $res=&unescape($res);
  852:             my $include=1;
  853:             if (($filters{'username'}) && ($uname ne $filters{'username'})) 
  854:                                                                { $include=0; }
  855:             if (($filters{'domain'}) && ($udom ne $filters{'domain'})) 
  856:                                                                { $include=0; }
  857:             if (($filters{'url'}) && ($res!~/$filters{'url'}/)) 
  858:                                                                { $include=0; }
  859:             if (($filters{'start'}) && ($time<$filters{'start'})) 
  860:                                                                { $include=0; }
  861:             if (($filters{'end'}) && ($time>$filters{'end'})) 
  862:                                                                { $include=0; }
  863:             if (($filters{'action'} eq 'view') && ($action)) 
  864:                                                                { $include=0; }
  865:             if (($filters{'action'} eq 'submit') && ($action ne 'POST')) 
  866:                                                                { $include=0; }
  867:             if (($filters{'action'} eq 'grade') && ($action ne 'CSTORE')) 
  868:                                                                { $include=0; }
  869:             if ($include) {
  870: 	       push(@results,($time<1000000000?'0':'').$time.':'.$res.':'.
  871:                                             $uname.':'.$udom.':'.
  872:                                             $action.':'.$values);
  873:             }
  874:        }
  875:     }
  876:     close IN;
  877:     return join('&',sort(@results));
  878: }
  879: 
  880: ########################################################
  881: ########################################################
  882: 
  883: =pod
  884: 
  885: =item &userlog
  886: 
  887: Inputs: $path, $command
  888: 
  889: Returns: unescaped string of values.
  890: 
  891: =cut
  892: 
  893: ########################################################
  894: ########################################################
  895: sub userlog {
  896:     my ($path,$command)=@_;
  897:     my %filters=();
  898:     foreach (split(/\:/,&unescape($command))) {
  899: 	my ($name,$value)=split(/\=/,$_);
  900:         $filters{$name}=$value;
  901:     }
  902:     my @results=();
  903:     open(IN,$path.'/activity.log') or return ('file_error');
  904:     while (my $line=<IN>) {
  905:         chomp($line);
  906:         my ($timestamp,$host,$log)=split(/\:/,$line);
  907:         $log=&unescape($log);
  908:         my $include=1;
  909:         if (($filters{'start'}) && ($timestamp<$filters{'start'})) 
  910:                                                              { $include=0; }
  911:         if (($filters{'end'}) && ($timestamp>$filters{'end'})) 
  912:                                                              { $include=0; }
  913:         if (($filters{'action'} eq 'log') && ($log!~/^Log/)) { $include=0; }
  914:         if (($filters{'action'} eq 'check') && ($log!~/^Check/)) 
  915:                                                              { $include=0; }
  916:         if ($include) {
  917: 	   push(@results,$timestamp.':'.$log);
  918:         }
  919:     }
  920:     close IN;
  921:     return join('&',sort(@results));
  922: }
  923: 
  924: ########################################################
  925: ########################################################
  926: 
  927: =pod
  928: 
  929: =item Functions required for forking
  930: 
  931: =over 4
  932: 
  933: =item REAPER
  934: 
  935: REAPER takes care of dead children.
  936: 
  937: =item HUNTSMAN
  938: 
  939: Signal handler for SIGINT.
  940: 
  941: =item HUPSMAN
  942: 
  943: Signal handler for SIGHUP
  944: 
  945: =item DISCONNECT
  946: 
  947: Disconnects from database.
  948: 
  949: =back
  950: 
  951: =cut
  952: 
  953: ########################################################
  954: ########################################################
  955: sub REAPER {                   # takes care of dead children
  956:     $SIG{CHLD} = \&REAPER;
  957:     my $pid = wait;
  958:     $children --;
  959:     &logthis("Child $pid died");
  960:     delete $children{$pid};
  961: }
  962: 
  963: sub HUNTSMAN {                      # signal handler for SIGINT
  964:     local($SIG{CHLD}) = 'IGNORE';   # we're going to kill our children
  965:     kill 'INT' => keys %children;
  966:     my $execdir=$perlvar{'lonDaemons'};
  967:     unlink("$execdir/logs/lonsql.pid");
  968:     &logthis("<font color='red'>CRITICAL: Shutting down</font>");
  969:     $unixsock = "mysqlsock";
  970:     my $port="$perlvar{'lonSockDir'}/$unixsock";
  971:     unlink($port);
  972:     exit;                           # clean up with dignity
  973: }
  974: 
  975: sub HUPSMAN {                      # signal handler for SIGHUP
  976:     local($SIG{CHLD}) = 'IGNORE';  # we're going to kill our children
  977:     kill 'INT' => keys %children;
  978:     close($server);                # free up socket
  979:     &logthis("<font color='red'>CRITICAL: Restarting</font>");
  980:     my $execdir=$perlvar{'lonDaemons'};
  981:     $unixsock = "mysqlsock";
  982:     my $port="$perlvar{'lonSockDir'}/$unixsock";
  983:     unlink($port);
  984:     exec("$execdir/lonsql");         # here we go again
  985: }
  986: 
  987: sub DISCONNECT {
  988:     $dbh->disconnect or 
  989:     &logthis("<font color='blue'>WARNING: Couldn't disconnect from database ".
  990:              " $DBI::errstr : $@</font>");
  991:     exit;
  992: }
  993: 
  994: 
  995: =pod
  996: 
  997: =back
  998: 
  999: =cut

FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>