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Memory	[ DIR ]	drwxr-xr-x
Null	[ DIR ]	drwxr-xr-x
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BaseCache.pm	14.73 KB	-rw-r--r--
BaseCacheTester.pm	2.76 KB	-rw-r--r--
Cache.pm	8.22 KB	-rw-r--r--
CacheMetaData.pm	5.73 KB	-rw-r--r--
CacheSizer.pm	3.94 KB	-rw-r--r--
CacheTester.pm	13.05 KB	-rw-r--r--
CacheUtils.pm	2.85 KB	-rw-r--r--
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File.pm	16.72 KB	-rw-r--r--
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IOString.pm	3.24 KB	-rw-r--r--
Memory.pm	9.64 KB	-rw-r--r--
MemoryBackend.pm	2.57 KB	-rw-r--r--
MemoryCache.pm	2.76 KB	-rw-r--r--
Null.pm	2.27 KB	-rw-r--r--
NullCache.pm	2.21 KB	-rw-r--r--
Object.pm	3.4 KB	-rw-r--r--
RemovalStrategy.pm	1.03 KB	-rw-r--r--
SharedMemoryBackend.pm	4.72 KB	-rw-r--r--
SharedMemoryCache.pm	3.4 KB	-rw-r--r--
SizeAwareCache.pm	3.04 KB	-rw-r--r--
SizeAwareCacheTester.pm	5.66 KB	-rw-r--r--
SizeAwareFileCache.pm	3.68 KB	-rw-r--r--
SizeAwareMemoryCache.pm	3.35 KB	-rw-r--r--
SizeAwareSharedMemoryCache.pm	2.55 KB	-rw-r--r--
Tester.pm	13.44 KB	-rw-r--r--

Code Editor : SharedMemoryBackend.pm

######################################################################
# $Id: SharedMemoryBackend.pm,v 1.7 2003/04/15 14:46:23 dclinton Exp $
# Copyright (C) 2001-2003 DeWitt Clinton  All Rights Reserved
#
# Software distributed under the License is distributed on an "AS
# IS" basis, WITHOUT WARRANTY OF ANY KIND, either expressed or
# implied. See the License for the specific language governing
# rights and limitations under the License.
######################################################################

package Cache::SharedMemoryBackend;

use strict;
use Cache::CacheUtils qw( Assert_Defined Freeze_Data Static_Params Thaw_Data );
use Cache::MemoryBackend;
use IPC::ShareLite qw( LOCK_EX LOCK_UN );

use vars qw( @ISA );

@ISA = qw ( Cache::MemoryBackend );

my $IPC_IDENTIFIER = 'ipcc';

sub new
{
  my ( $proto ) = @_;
  my $class = ref( $proto ) || $proto;
  return $class->SUPER::new( );
}

sub delete_key
{
  my ( $self, $p_namespace, $p_key ) = @_;

my $store_ref = $self->_get_locked_store_ref( );

delete $store_ref->{ $p_namespace }{ $p_key };

$self->_set_locked_store_ref( $store_ref );
}

sub delete_namespace
{
  my ( $self, $p_namespace ) = @_;

my $store_ref = $self->_get_locked_store_ref( );

delete $store_ref->{ $p_namespace };

$self->_set_locked_store_ref( $store_ref );
}

sub store
{
  my ( $self, $p_namespace, $p_key, $p_data ) = @_;

my $store_ref = $self->_get_locked_store_ref( );

$store_ref->{ $p_namespace }{ $p_key } = $p_data;

$self->_set_locked_store_ref( $store_ref );
}

# create a IPC::ShareLite share under the ipc_identifier

sub _Instantiate_Share
{
  my ( $p_ipc_identifier ) = Static_Params( @_ );

Assert_Defined( $p_ipc_identifier );

my %ipc_options = (
                     -key       =>  $p_ipc_identifier,
                     -create    => 'yes',
                     -destroy   => 'no',
                     -exclusive => 'no'
                    );

my $share = new IPC::ShareLite( %ipc_options ) or
    throw Error::Simple( "Couldn't instantiate IPC::ShareLite: $!" );

return $share;
}

# this method uses the shared created by Instantiate_Share to
# transparently retrieve a reference to a shared hash structure

sub _Restore_Shared_Hash_Ref
{
  my ( $p_ipc_identifier ) = Static_Params( @_ );

Assert_Defined( $p_ipc_identifier );

my $frozen_hash_ref = _Instantiate_Share( $p_ipc_identifier )->fetch( ) or
    return { };

return Thaw_Data( $frozen_hash_ref );
}

# this method uses the shared created by Instantiate_Share to
# transparently retrieve a reference to a shared hash structure, and
# additionally exclusively locks the share

sub _Restore_Shared_Hash_Ref_With_Lock
{
  my ( $p_ipc_identifier ) = Static_Params( @_ );

Assert_Defined( $p_ipc_identifier );

my $share = _Instantiate_Share( $p_ipc_identifier );

$share->lock( LOCK_EX );

my $frozen_hash_ref = $share->fetch( ) or
    return { };

return Thaw_Data( $frozen_hash_ref );
}

# this method uses the shared created by Instantiate_Share to
# transparently persist a reference to a shared hash structure

sub _Store_Shared_Hash_Ref
{
  my ( $p_ipc_identifier, $p_hash_ref ) = @_;

Assert_Defined( $p_ipc_identifier );
  Assert_Defined( $p_hash_ref );

_Instantiate_Share( $p_ipc_identifier )->store( Freeze_Data( $p_hash_ref ) );
}

# this method uses the shared created by Instantiate_Share to
# transparently persist a reference to a shared hash structure and
# additionally unlocks the share

sub _Store_Shared_Hash_Ref_And_Unlock
{
  my ( $p_ipc_identifier, $p_hash_ref ) = @_;

Assert_Defined( $p_ipc_identifier );
  Assert_Defined( $p_hash_ref );

my $share = _Instantiate_Share( $p_ipc_identifier );

$share->store( Freeze_Data( $p_hash_ref ) );

$share->unlock( LOCK_UN );
}

sub _get_locked_store_ref
{
  return _Restore_Shared_Hash_Ref_With_Lock( $IPC_IDENTIFIER );
}

sub _set_locked_store_ref
{
  my ( $self, $p_store_ref ) = @_;

_Store_Shared_Hash_Ref_And_Unlock( $IPC_IDENTIFIER, $p_store_ref );
}

sub _get_store_ref
{
  return _Restore_Shared_Hash_Ref( $IPC_IDENTIFIER );
}

sub _set_store_ref
{
  my ( $self, $p_store_ref ) = @_;

_Store_Shared_Hash_Ref( $IPC_IDENTIFIER, $p_store_ref );
}

__END__

=pod

=head1 NAME

Cache::SharedMemoryBackend -- a shared memory based persistence mechanism

=head1 DESCRIPTION

The SharedMemoryBackend class is used to persist data to shared memory

=head1 SYNOPSIS

my $backend = new Cache::SharedMemoryBackend( );

See Cache::Backend for the usage synopsis.

=head1 METHODS

See Cache::Backend for the API documentation.

=head1 SEE ALSO

Cache::Backend, Cache::FileBackend, Cache::ShareMemoryBackend

=head1 AUTHOR

Original author: DeWitt Clinton <dewitt@unto.net>

Last author:     $Author: dclinton $

=cut

${this.title}

Code Editor : SharedMemoryBackend.pm