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Support delayed transactions... this is done uniformly by encapsulating
transactions in an object ... a LondTransaction that is implemented by
LondTransaction.pm

    1: #   This module defines and implements a class that represents
    2: #   a connection to a lond daemon.
    3: #
    4: # $Id: LondTransaction.pm,v 1.5 2003/06/11 02:04:35 foxr Exp $
    5: #
    6: # Copyright Michigan State University Board of Trustees
    7: #
    8: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
    9: #
   10: # LON-CAPA is free software; you can redistribute it and/or modify
   11: # it under the terms of the GNU General Public License as published by
   12: # the Free Software Foundation; either version 2 of the License, or
   13: # (at your option) any later version.
   14: #
   15: # LON-CAPA is distributed in the hope that it will be useful,
   16: # but WITHOUT ANY WARRANTY; without even the implied warranty of
   17: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   18: # GNU General Public License for more details.
   19: #
   20: # You should have received a copy of the GNU General Public License
   21: # along with LON-CAPA; if not, write to the Free Software
   22: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   23: #
   24: # /home/httpd/html/adm/gpl.txt
   25: #
   26: # http://www.lon-capa.org/
   27: #
   28: 
   29: =pod
   30: 
   31: =head1 Synopsis
   32: 
   33:   LondTransaction objectifies the state of a transaction between lonc and
   34:   lond (loncnew really).  
   35: 
   36: =cut
   37: 
   38: package LondTransaction;
   39: 
   40: =pod
   41: =head1 Description
   42: 
   43: LondTransaction objects hold the state required to manage a 
   44: transaction between lonc and lond, from the loncnew point of view.
   45: The state consists of the following member data:
   46: 
   47: =item request
   48: 
   49: The text of the request to send to lond.
   50: 
   51: =item active
   52: 
   53: If zero, the request is not active and the londSocket item is not
   54: defined.
   55: 
   56: =item londSocket
   57: 
   58: If the request is active,
   59: this member contains the LondConnection object reference that
   60: this request is being processed on.
   61: 
   62: =item deferred
   63: 
   64: True if the request is a deferred (delayed) request.
   65: The member data below are either present or not depending on 
   66: whether or not deferred is true.
   67: 
   68: =item clientSocket
   69:    
   70: If deferred is false, this member data is defined and is the 
   71: handle to the socket that is connected to the apache child that
   72: has requested this transaction.
   73: 
   74: =item DeferredFile
   75: 
   76: If deferred is false, this member data is defined and is the name
   77: of the file that contains the deferred request.  When the transaction
   78: is retired, this file will be deleted.
   79: 
   80: =head1 Member Functions
   81: 
   82: =head2  Operational functions
   83: 
   84: =cut
   85: 
   86: =pod
   87: 
   88: =item new
   89: 
   90: Creates a new transaction object.
   91: 
   92: =cut
   93: 
   94: sub new {
   95:     my $class       = shift;
   96:     my $Transaction = shift;
   97: 
   98:     
   99:     my $self   = {request     => $Transaction,
  100: 		  active      => 0,
  101: 		  deferred    => 0};
  102:     bless($self, $class);
  103:     return $self;
  104: }
  105: =pod
  106: 
  107: =item Activate
  108: 
  109: Activates the transaction by assigning it to a LondConnection object
  110: 
  111: Parameters:
  112: 
  113: =over 3
  114: 
  115: =item  Connection
  116: 
  117: 
  118: Reference to the LondConnection object along which the transaction
  119: will be carried.
  120: 
  121: =back 
  122: 
  123: =cut
  124: sub Activate {
  125:     my $self       = shift;
  126:     my $Connection = shift;	# Reference to a lond connection.
  127: 
  128:     $self->{londSocket} = $Connection; # Store the connection object and
  129:     $self->{active}     = 1;	       # Indicate it's active.
  130: 
  131: }
  132: 
  133: =pod
  134: 
  135: =item Retire
  136: 
  137: 
  138: Retires a transaction after successful completion.  If the
  139: transaction is deferred, the deferred file is destroyed.
  140: Otherwise this is a noop.
  141: 
  142: =cut
  143: sub Retire {
  144:     my $self     = shift;
  145: 
  146:     if($self->{deferred}) {
  147: 	unlink $self->{DeferredFile};
  148:     }
  149: 
  150:     #  Destroy my member data to release reference counts.
  151: 
  152:     delete $self->{londSocket};
  153:     delete $self->{clientSocket};
  154:     delete $self->{DeferredFile};
  155: 
  156: }
  157: 
  158: =pod
  159: 
  160: =item SetDeferred
  161: 
  162: Sets the state of a transaction to deferred, the deferred member
  163: is set true, clientSocket is undefined, and DeferredFile is set.
  164: 
  165: Parameters:
  166:  
  167: =over 3
  168: 
  169: =item File
  170: 
  171: Name of the file that holds the deferred transaction.
  172: 
  173: =back 
  174: 
  175: =cut
  176: sub SetDeferred {
  177:     my $self   = shift;
  178:     my $File   = shift;
  179: 
  180:     $self->{deferred}      = 1;
  181:     $self->{DeferredFile} = $File;
  182: }
  183: 
  184: =pod
  185: 
  186: =item  SetClient
  187: 
  188: Sets the state of a transaction to not deferred.  The deferred member
  189: is set false, clientSocket is set and DeferredFile is undefined.
  190: 
  191: Parameters:
  192: 
  193: =over 3
  194: 
  195: =item Socket
  196: 
  197:   The socket open on the client.
  198: 
  199: =back
  200: 
  201: =cut
  202: sub SetClient {
  203:     my $self   = shift;
  204:     my $Client = shift;
  205:     
  206:     $self->{deferred}     = 0;
  207:     $self->{clientSocket} = $Client; 
  208: }
  209: 
  210: =pod
  211: 
  212: =head2  Selectors
  213: 
  214: 
  215: =item isDeferred
  216: 
  217: Returns the state of the deferred member.
  218: 
  219: =cut
  220: sub isDeferred {
  221:     my $self   = shift;
  222:     return $self->{deferred};
  223: }
  224: 
  225: =pod
  226: 
  227: =item isActive
  228: 
  229: Returns the value of the active member.
  230: 
  231: =cut
  232: sub isActive {
  233:     my $self = shift;
  234:     return $self->{active};
  235: }
  236: 
  237: =pod
  238: 
  239: =item getClient
  240: 
  241: If not deferred returns the client socket, else returns undef.
  242: 
  243: =cut
  244: sub getClient {
  245:     my $self = shift;
  246:     if($self->{deferred}) {
  247: 	return undef;
  248:     } else {
  249: 	return $self->{clientSocket};
  250:     }
  251: }
  252: 
  253: 
  254: =pod
  255: 
  256: =item getFile
  257: 
  258: If deferred, returns the name of the deferred queue file else
  259: returns undef.
  260: 
  261: =cut
  262: sub getFile {
  263:     my $self = shift;
  264:     if($self->{deferred}) {
  265: 	return $self->{DeferredFile};
  266:     } else {
  267: 	return undef;
  268:     }
  269: }
  270: 
  271: 
  272: =pod
  273: 
  274: =item getServer
  275: 
  276:   If active returns the lond server socket else undef.
  277: 
  278: =cut
  279: sub getServer {
  280:     my $self  = shift;
  281: 
  282:     if($self->{active}) {
  283: 	return $self->{londSocket};
  284:     } else {
  285: 	return undef;
  286:     }
  287: }
  288: 
  289: =pod
  290: 
  291: =item getRequest
  292: 
  293:   Returns the remaining request text.
  294: 
  295: =cut
  296: sub getRequest {
  297:     my $self = shift;
  298:     return $self->{request};
  299: }
  300: 
  301: 
  302: 1;