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Member "Apache-Session-1.93/lib/Apache/Session/Lock/Sybase.pm" (15 Sep 2009, 3789 Bytes) of package /linux/www/Apache-Session-1.93.tar.gz:


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    1 ############################################################################
    2 #
    3 # Apache::Session::Lock::Sybase
    4 # Sybase locking for Apache::Session
    5 # Copyright(c) 2003 Oliver Maul (oli@42.nu)
    6 # Distribute under the Perl License
    7 #
    8 ############################################################################
    9 
   10 package Apache::Session::Lock::Sybase;
   11 
   12 use strict;
   13 
   14 use DBI;
   15 use vars qw($VERSION);
   16 
   17 $VERSION = '1.00';
   18 
   19 sub new {
   20     my $class = shift;
   21     
   22     return bless {lock => 0, lockid => undef, dbh => undef, mine => 0}, $class;
   23 }
   24 
   25 sub acquire_read_lock  {
   26     my $self    = shift;
   27     my $session = shift;
   28     
   29     return if $self->{lock};
   30 
   31     if (!defined $self->{dbh}) {
   32         if (defined $session->{args}->{LockHandle}) {
   33             $self->{dbh} = $session->{args}->{LockHandle};
   34         }
   35         else {
   36             $self->{dbh} = DBI->connect(
   37                 $session->{args}->{LockDataSource},
   38                 $session->{args}->{LockUserName},
   39                 $session->{args}->{LockPassword},
   40                 { RaiseError => 1, AutoCommit => 1 }
   41             );
   42             $self->{mine} = 1;
   43         }
   44     }
   45 
   46     local $self->{dbh}->{RaiseError} = 1;
   47 
   48     $self->{lockid} = "Apache-Session-$session->{data}->{_session_id}";
   49     
   50     my $sth = $self->{dbh}->prepare(q{sp_getapplock @Resource = '}.$self->{lockid}.q{',@LockMode='Exclusive',@LockOwner='Session',@LockTimeout = '3600000'});
   51     $sth->execute() || die $DBI::errstr;
   52     
   53     $self->{lock} = 1;
   54 }
   55 
   56 sub acquire_write_lock {
   57     $_[0]->acquire_read_lock($_[1]);
   58 }
   59 
   60 sub release_read_lock {
   61     my $self = shift;
   62 
   63     if ($self->{lock}) {
   64         local $self->{dbh}->{RaiseError} = 1;
   65         
   66         my $sth = $self->{dbh}->prepare(q{sp_releaseapplock @Resource='}.$self->{lockid}.q{',@Lookowner='Session'});
   67         $sth->execute() || die $DBI::errstr;
   68         
   69         $self->{lock} = 0;
   70     } 
   71 }
   72 
   73 sub release_write_lock {
   74     $_[0]->release_read_lock;
   75 }
   76 
   77 sub release_all_locks  {
   78     $_[0]->release_read_lock;
   79 }
   80 
   81 sub DESTROY {
   82     my $self = shift;
   83     
   84     $self->release_all_locks;
   85     
   86     if ($self->{mine}) {
   87         $self->{dbh}->disconnect;
   88     }
   89 }
   90 
   91 1;
   92 
   93 =pod
   94 
   95 =head1 NAME
   96 
   97 Apache::Session::Lock::Sybase - Provides mutual exclusion using Sybase
   98 
   99 =head1 SYNOPSIS
  100 
  101  use Apache::Session::Lock::Sybase;
  102 
  103  my $locker = new Apache::Session::Lock::Sybase;
  104 
  105  $locker->acquire_read_lock($ref);
  106  $locker->acquire_write_lock($ref);
  107  $locker->release_read_lock($ref);
  108  $locker->release_write_lock($ref);
  109  $locker->release_all_locks($ref);
  110 
  111 =head1 DESCRIPTION
  112 
  113 Apache::Session::Lock::Sybase fulfills the locking interface of 
  114 Apache::Session.  Mutual exclusion is achieved through the use of Sybase's
  115 sp_getapplock and sp_releaseapplock functions. Sybase does not support the
  116 notion
  117 of read and write locks, so this module only supports exclusive locks.  When
  118 you request a shared read lock, it is instead promoted to an exclusive
  119 write lock.
  120 
  121 =head1 CONFIGURATION
  122 
  123 The module must know how to connect to your MySQL database to acquire locks.
  124 You must provide a datasource name, a user name, and a password.  These options
  125 are passed in the usual Apache::Session style, and are very similar to the
  126 options for Apache::Session::Store::Sybase.  Example:
  127 
  128  tie %hash, 'Apache::Session::Sybase', $id, {
  129      LockDataSource => 'dbi:sybase:database',
  130      LockUserName   => 'database_user',
  131      LockPassword   => 'K00l'
  132  };
  133 
  134 Instead, you may pass in an already opened DBI handle to your database.
  135 
  136  tie %hash, 'Apache::Session::Sybase', $id, {
  137      LockHandle => $dbh
  138  };
  139 
  140 =head1 AUTHOR
  141 
  142 This module was written by Oliver Maul <oli@42.nu>.
  143 
  144 =head1 SEE ALSO
  145 
  146 L<Apache::Session>