Storage/Handler/Abstract.pm

#################################
#
#  $Id: Abstract.pm,v 1.2 2002/10/17 00:08:07 joko Exp $
#
#  $Log: Abstract.pm,v $
#  Revision 1.2  2002/10/17 00:08:07  joko
#  + bugfixes regarding "deep recursion" stuff
#
#  Revision 1.1  2002/10/10 03:44:07  cvsjoko
#  + new
#
#
#################################

package Data::Storage::Handler::Abstract;

use strict;
use warnings;

use Data::Dumper;

# get logger instance
my $logger = Log::Dispatch::Config->instance;

#our $lock_info;

sub new {
  my $invocant = shift;
  my $class = ref($invocant) || $invocant;
  
  # logging info about the actual handler called
    $logger->debug( "$invocant->new( @_ )" );
    #$logger->debug( __PACKAGE__ . "->" . "new()" );

  # arguments become properties
  my $self = { @_ };
  # create object from blessed hash-reference
  bless $self, $class;

  # handle meta data
    #my $metainfo = $self->getMetaInfo($class);
    my $metainfo = $self->getMetaInfo();
    if (!$metainfo->{disconnectMethod}) { $metainfo->{disconnectMethod} = 'disconnect'; }
    # type?
    $invocant =~ s/Data::Storage::Handler:://;
    $metainfo->{type} = $invocant;

    # direct accessible (non-protected) properties         ( was: my $self = { }; )
    $self->{metainfo} = $metainfo;

  return $self;
}


sub AUTOLOAD {

  # recursion problem to be avoided here!!!
  
    # - problem: we get recursion-hangs!!!   =>  perl stops with ...
    # "Deep recursion on subroutine "Data::Storage::Handler::Abstract::AUTOLOAD" at [...]/libs/Data/Storage.pm line 38."
    
    # - when: if we log to ourselves as a storage-implementation (e.g. via Log::Dispatch::Tangram)
    # - why:  debug-messages are on a very low level including every data-operation to "Data::Storage(::Handler::X)",
    #             so e.g. a "$storage->insert" would trigger another "$storage->insert" itself 
    #             which leads to a infinite recursion loop (deep recursion)
    # - solution: locks! (by Hack or (maybe) via Perl "local"s)

  my $self = shift;

  our $AUTOLOAD;
  #return if $AUTOLOAD =~ m/::DESTROY$/;

  # find out methodname
  my $methodname = $AUTOLOAD;
  $methodname =~ s/^.*:://;

  # handle locking (hack)
  if ($self->{lock_info}->{last_method} && $methodname eq $self->{lock_info}->{last_method}) {
    $self->{lock_info}->{log_lock} = 1;
  } else {
    $self->{lock_info}->{log_lock} = 0;
  }
  $self->{lock_info}->{last_method} = $methodname;
  
  # test for COREHANDLE
  if (!$self->{COREHANDLE}) {
    #print "no COREHANDLE", "\n";
    if (!$self->{lock_info}->{log_lock}) {
      $logger->error( __PACKAGE__ . "[$self->{metainfo}->{type}]" . ": " . "COREHANDLE is undefined while trying to execute method \"$methodname\"" );
    }
    return;
  }

  # try to dispatch method-call to Storage::Handler::*
  #if ($self->can($methodname)) {
    #$logger->debug( __PACKAGE__ . "[$self->{metainfo}->{type}]" . "->" . $methodname . "(@_)" );
    #my $res = $self->$methodname(@_);
    #if ($res) { return $res; }
  #}

  # try to dispatch method-call to COREHANDLE
  if ($self->{COREHANDLE}->can($methodname) || $self->{COREHANDLE}->can("AUTOLOAD")) {
    #$logger->debug( __PACKAGE__ . "->" . $methodname . " (AUTOLOAD)" );
    #$lock_AUTOLOAD = 1 if ($methodname eq 'insert');
    if (!$self->{lock_info}->{log_lock}) {
      #print "method: $methodname", "\n";
      $logger->debug( __PACKAGE__ . "[$self->{metainfo}->{type}]" . "->" . $methodname . "(@_)" );
    } else {
      # AUTOLOAD - sub is locked to prevent deep recursions if (e.g.) db-inserts cause log-actions to same db itself
    }
    #$lock_AUTOLOAD = 0;
    #$logger->log( level => 'debug', message => __PACKAGE__ . "->" . $methodname . " (AUTOLOAD)" );
    
    # method calls doing it until here will get dispatched to the proper handler
    return $self->{COREHANDLE}->$methodname(@_);
  }

}

sub DESTROY {
  my $self = shift;
  if ($self->{COREHANDLE}) {
    $logger->debug( __PACKAGE__ . "[$self->{metainfo}->{type}]" . "->DESTROY" );

    my $disconnectMethod = $self->{metainfo}->{disconnectMethod};

    # call "disconnect" or alike on COREHANDLE
    # was: $self->{COREHANDLE}->disconnect();
    $disconnectMethod && ( $self->{COREHANDLE}->$disconnectMethod() );

    undef $self->{COREHANDLE};
  }
}


sub _abstract_function {
  my $self = shift;
  my $fName = shift;
  my $class = ref($self);
  $logger->error( __PACKAGE__ . ": function \"$fName\" is an abstract method, please implement it in \"$class\"");
  #exit;
}

sub _typeCheck {
  my $type = shift;
  print "type: $type";
  eval("use Data::Storage::$type;");
}


# ====================================================
#   PUBLIC METHODS
# ====================================================

  sub existsChildNode {
    my $self = shift;
    my $nodename = shift;
    #$nodename = 'TransactionRoutingTable';
    $logger->debug( __PACKAGE__ . "->getChildNode( nodename $nodename )" );
    $self->getChildNodes() unless $self->{meta}->{childnodes};
    my $result = grep(m/$nodename/i, @{$self->{meta}->{childnodes}});     # TODO: use "/i" only on win32-systems!
    return $result;
  }

  sub connect_tmp {
    
#    my $self = shift;
#    my $connectionString = shift;
#    # todo: patch connectionString to $args
#    _typeCheck($self->{args}{type});

  }
  

# ====================================================
#   CONCRETE METHOD DUMMIES (croaking via "$logger" by calling "_abstract_function")
# ====================================================

  # TODO:
  #   - abstract "abstract methods" to list/hash to be used in AUTOLOAD
  #      e.g.: my @ABSTRACT_METHODS = (qw( connect sendCommand getChildNodes ));
  #   - build them via anonymous subs 
  #   - introduce them via symbols

  sub sendCommand {
    my $self = shift;
    $self->_abstract_function('sendCommand');
  }

  sub getChildNodes {
    my $self = shift;
    $self->_abstract_function('getChildNodes');
  }

  sub configureCOREHANDLE {
    my $self = shift;
    $self->_abstract_function('configureCOREHANDLE');
  }

  sub getMetaInfo {
    my $self = shift;
    $self->_abstract_function('getMetaInfo');
    return;
  }

  sub getListUnfiltered {
    my $self = shift;
    $self->_abstract_function('getListUnfiltered');
    return;
  }

  sub getListFiltered {
    my $self = shift;
    $self->_abstract_function('getListFiltered');
    return;
  }

  sub sendQuery {
    my $self = shift;
    $self->_abstract_function('sendQuery');
    return;
  }

  sub connect {
    my $self = shift;
    $self->_abstract_function('connect');
    return;
  }

  sub testIntegrity {
    my $self = shift;
    $self->_abstract_function('testIntegrity');
    return;
  }

  sub quoteSql {
    my $self = shift;
    $self->_abstract_function('quoteSql');
    return;
  }

1;
1	cvsjoko	1.1	#################################
2			#
3	joko	1.3	# $Id: Abstract.pm,v 1.2 2002/10/17 00:08:07 joko Exp $
4	joko	1.2	#
5			# $Log: Abstract.pm,v $
6	joko	1.3	# Revision 1.2 2002/10/17 00:08:07 joko
7			# + bugfixes regarding "deep recursion" stuff
8			#
9	joko	1.2	# Revision 1.1 2002/10/10 03:44:07 cvsjoko
10			# + new
11	cvsjoko	1.1	#
12			#
13			#################################
14
15			package Data::Storage::Handler::Abstract;
16
17			use strict;
18			use warnings;
19
20			use Data::Dumper;
21
22			# get logger instance
23			my $logger = Log::Dispatch::Config->instance;
24
25			#our $lock_info;
26
27			sub new {
28			my $invocant = shift;
29			my $class = ref($invocant) \|\| $invocant;
30
31			# logging info about the actual handler called
32			$logger->debug( "$invocant->new( @_ )" );
33	joko	1.2	#$logger->debug( __PACKAGE__ . "->" . "new()" );
34	cvsjoko	1.1
35	joko	1.3	# arguments become properties
36			my $self = { @_ };
37			# create object from blessed hash-reference
38			bless $self, $class;
39
40	cvsjoko	1.1	# handle meta data
41	joko	1.3	#my $metainfo = $self->getMetaInfo($class);
42			my $metainfo = $self->getMetaInfo();
43	cvsjoko	1.1	if (!$metainfo->{disconnectMethod}) { $metainfo->{disconnectMethod} = 'disconnect'; }
44			# type?
45			$invocant =~ s/Data::Storage::Handler:://;
46			$metainfo->{type} = $invocant;
47
48			# direct accessible (non-protected) properties ( was: my $self = { }; )
49	joko	1.3	$self->{metainfo} = $metainfo;
50	cvsjoko	1.1
51			return $self;
52			}
53
54
55			sub AUTOLOAD {
56
57			# recursion problem to be avoided here!!!
58
59			# - problem: we get recursion-hangs!!! => perl stops with ...
60			# "Deep recursion on subroutine "Data::Storage::Handler::Abstract::AUTOLOAD" at [...]/libs/Data/Storage.pm line 38."
61
62			# - when: if we log to ourselves as a storage-implementation (e.g. via Log::Dispatch::Tangram)
63			# - why: debug-messages are on a very low level including every data-operation to "Data::Storage(::Handler::X)",
64			# so e.g. a "$storage->insert" would trigger another "$storage->insert" itself
65			# which leads to a infinite recursion loop (deep recursion)
66	joko	1.2	# - solution: locks! (by Hack or (maybe) via Perl "local"s)
67	cvsjoko	1.1
68			my $self = shift;
69
70			our $AUTOLOAD;
71			#return if $AUTOLOAD =~ m/::DESTROY$/;
72
73			# find out methodname
74			my $methodname = $AUTOLOAD;
75			$methodname =~ s/^.*:://;
76
77			# handle locking (hack)
78			if ($self->{lock_info}->{last_method} && $methodname eq $self->{lock_info}->{last_method}) {
79			$self->{lock_info}->{log_lock} = 1;
80			} else {
81			$self->{lock_info}->{log_lock} = 0;
82			}
83			$self->{lock_info}->{last_method} = $methodname;
84
85			# test for COREHANDLE
86			if (!$self->{COREHANDLE}) {
87	joko	1.2	#print "no COREHANDLE", "\n";
88			if (!$self->{lock_info}->{log_lock}) {
89			$logger->error( __PACKAGE__ . "[$self->{metainfo}->{type}]" . ": " . "COREHANDLE is undefined while trying to execute method \"$methodname\"" );
90			}
91	cvsjoko	1.1	return;
92			}
93
94			# try to dispatch method-call to Storage::Handler::*
95			#if ($self->can($methodname)) {
96			#$logger->debug( __PACKAGE__ . "[$self->{metainfo}->{type}]" . "->" . $methodname . "(@_)" );
97			#my $res = $self->$methodname(@_);
98			#if ($res) { return $res; }
99			#}
100
101			# try to dispatch method-call to COREHANDLE
102			if ($self->{COREHANDLE}->can($methodname) \|\| $self->{COREHANDLE}->can("AUTOLOAD")) {
103			#$logger->debug( __PACKAGE__ . "->" . $methodname . " (AUTOLOAD)" );
104			#$lock_AUTOLOAD = 1 if ($methodname eq 'insert');
105			if (!$self->{lock_info}->{log_lock}) {
106			#print "method: $methodname", "\n";
107			$logger->debug( __PACKAGE__ . "[$self->{metainfo}->{type}]" . "->" . $methodname . "(@_)" );
108			} else {
109			# AUTOLOAD - sub is locked to prevent deep recursions if (e.g.) db-inserts cause log-actions to same db itself
110			}
111			#$lock_AUTOLOAD = 0;
112			#$logger->log( level => 'debug', message => __PACKAGE__ . "->" . $methodname . " (AUTOLOAD)" );
113	joko	1.3
114			# method calls doing it until here will get dispatched to the proper handler
115	cvsjoko	1.1	return $self->{COREHANDLE}->$methodname(@_);
116			}
117
118			}
119
120			sub DESTROY {
121			my $self = shift;
122			if ($self->{COREHANDLE}) {
123			$logger->debug( __PACKAGE__ . "[$self->{metainfo}->{type}]" . "->DESTROY" );
124
125			my $disconnectMethod = $self->{metainfo}->{disconnectMethod};
126
127			# call "disconnect" or alike on COREHANDLE
128			# was: $self->{COREHANDLE}->disconnect();
129			$disconnectMethod && ( $self->{COREHANDLE}->$disconnectMethod() );
130
131			undef $self->{COREHANDLE};
132			}
133			}
134
135
136			sub _abstract_function {
137			my $self = shift;
138			my $fName = shift;
139			my $class = ref($self);
140			$logger->error( __PACKAGE__ . ": function \"$fName\" is an abstract method, please implement it in \"$class\"");
141			#exit;
142			}
143
144			sub _typeCheck {
145			my $type = shift;
146			print "type: $type";
147			eval("use Data::Storage::$type;");
148			}
149
150
151			# ====================================================
152			# PUBLIC METHODS
153			# ====================================================
154
155	joko	1.3	sub existsChildNode {
156			my $self = shift;
157			my $nodename = shift;
158			#$nodename = 'TransactionRoutingTable';
159			$logger->debug( __PACKAGE__ . "->getChildNode( nodename $nodename )" );
160			$self->getChildNodes() unless $self->{meta}->{childnodes};
161			my $result = grep(m/$nodename/i, @{$self->{meta}->{childnodes}}); # TODO: use "/i" only on win32-systems!
162			return $result;
163			}
164	cvsjoko	1.1
165	joko	1.3	sub connect_tmp {
166	cvsjoko	1.1
167			# my $self = shift;
168			# my $connectionString = shift;
169			# # todo: patch connectionString to $args
170			# _typeCheck($self->{args}{type});
171
172			}
173
174	joko	1.3
175			# ====================================================
176			# CONCRETE METHOD DUMMIES (croaking via "$logger" by calling "_abstract_function")
177			# ====================================================
178
179			# TODO:
180			# - abstract "abstract methods" to list/hash to be used in AUTOLOAD
181			# e.g.: my @ABSTRACT_METHODS = (qw( connect sendCommand getChildNodes ));
182			# - build them via anonymous subs
183			# - introduce them via symbols
184
185	cvsjoko	1.1	sub sendCommand {
186			my $self = shift;
187			$self->_abstract_function('sendCommand');
188			}
189
190			sub getChildNodes {
191			my $self = shift;
192			$self->_abstract_function('getChildNodes');
193			}
194
195			sub configureCOREHANDLE {
196			my $self = shift;
197			$self->_abstract_function('configureCOREHANDLE');
198			}
199
200	joko	1.3	sub getMetaInfo {
201			my $self = shift;
202			$self->_abstract_function('getMetaInfo');
203			return;
204			}
205
206			sub getListUnfiltered {
207			my $self = shift;
208			$self->_abstract_function('getListUnfiltered');
209			return;
210			}
211
212			sub getListFiltered {
213			my $self = shift;
214			$self->_abstract_function('getListFiltered');
215			return;
216			}
217
218			sub sendQuery {
219			my $self = shift;
220			$self->_abstract_function('sendQuery');
221			return;
222			}
223
224			sub connect {
225			my $self = shift;
226			$self->_abstract_function('connect');
227			return;
228			}
229
230			sub testIntegrity {
231			my $self = shift;
232			$self->_abstract_function('testIntegrity');
233			return;
234			}
235
236			sub quoteSql {
237			my $self = shift;
238			$self->_abstract_function('quoteSql');
239			return;
240			}
241
242			1;
MailToCvsAdmin">MailToCvsAdmin	ViewVC Help
Powered by ViewVC 1.1.26