src/Utilities/HashDB.pm

#
# HashDB.pm
#
# Originally Written by Christopher Williams
#
# Description
#
# Interface
# ---------
# new()         : A new HashDB object
# setdata(data, @keys)   : set a data item to the given keys
# getdata(@keys)         : return all data items that match the given keys
# deletedata(@keys)      : detete all data items that match the given keys
# match(@keys)           : return the full DataItem object refs that match keys
# items()                : return the number of seperate items in the store
# store(filename)        : dump to file
# restore(filename)      : restore from file
# alias(\@refofkeys,\@aliaskeys) : attatch another set of keys to items that 
#                                  match the refopfkeys
#                                  note that these are references to the arrays
# unalias(@aliaskeys) :remove an alias 

package Utilities::HashDB;
use Utilities::DataItem;
use FileHandle;
require 5.001;

sub new {
        my $class=shift;
        $self={};
        bless $self, $class;
        $self->{dataitems}=();
        return $self;
}

sub setdata {
        my $self=shift;
        my $data=shift;
        my @keys=@_;
        
        push @{$self->{dataitems}}, Utilities::DataItem->new($data, @keys);
}

sub alias {
        my $self=shift;
        my $keyref=shift;
        my $aliaskeys=shift;

        my @objs=$self->match(@{$keyref});
        foreach $obj ( @objs ) {
        print "$obj @_\n";
          $obj->alias(@{$aliaskeys});
        }
}

sub unalias {
        my $self=shift;
        my @keys=@_;

        my @objs=$self->match(@keys);
        foreach $obj ( @objs ) {
          $obj->unalias(@_);
        }
}

sub items {
        my $self=shift;
        return $#{$self->{dataitems}};
}

sub deletedata {
        my $self=shift;
        my @keys=@_;

        # first get all the keys we want to delete
        my @match=$self->_match(@keys);
        foreach $i ( @match ) {
          splice (@{$self->{dataitems}}, $i, 1 );
        }
}

sub match {
        my $self=shift;
        my @keys=@_;
        
        my @data=();
        my @match=$self->_match(@keys);
        foreach $i ( @match ) {
          push @data, $self->{dataitems}[$i];
        }
        return @data;
}

sub getdata {
        my $self=shift;
        my @keys=@_;
        
        my @data=();
        my @match=$self->_match(@keys);
        my $i;
        foreach $i ( @match ) {
          push @data, ($self->{dataitems}[$i]->data());
        }
        return @data;
}

sub store {
        my $self=shift;
        my $filename=shift;

        my $fh=FileHandle->new();
        $fh->autoflush(1);
        open ($fh, ">$filename") or die "Unable to open file $filename\n $!\n";
        foreach $object ( @{$self->{dataitems}} ) {
          print $fh "\n";
          $object->store($fh);
        }
        close $fh;
}

sub restore {
        my $self=shift;
        my $filename=shift;
        my @arr=();
        my $data;

        my $fh=FileHandle->new();
        open ($fh, "<$filename") or die "Unable to open file $filename\n $!\n";
        while ( <$fh> ) {
          push @{$self->{dataitems}}, Utilities::DataItem->restore($fh);
        }
        close $fh;
}

# ------------------- Support Routines ------------
# returns list of array indices of items matching the keys

sub _match {
        my $self=shift;
        my @keys=@_;

        my @matches=();
        my $data;
        for ( $i=0; $i<=$#{$self->{dataitems}}; $i++ ) {
          $data=$self->{dataitems}[$i];
          if ( $data->match(@keys) ) {
            push @matches, $i;
          }
        }
        return @matches;
}
Revision:	1.6
Committed:	Tue Feb 8 13:53:22 2000 UTC (25 years, 3 months ago) by williamc
Content type:	text/plain
Branch:	MAIN
Changes since 1.5:	+30 -15 lines
Log Message:	Add aliasing mechanism and make dataItem store its own data
#	User	Rev	Content
1	williamc	1.1	#
2			# HashDB.pm
3			#
4			# Originally Written by Christopher Williams
5			#
6			# Description
7			#
8			# Interface
9			# ---------
10			# new() : A new HashDB object
11			# setdata(data, @keys) : set a data item to the given keys
12			# getdata(@keys) : return all data items that match the given keys
13			# deletedata(@keys) : detete all data items that match the given keys
14	williamc	1.3	# match(@keys) : return the full DataItem object refs that match keys
15	williamc	1.1	# items() : return the number of seperate items in the store
16	williamc	1.4	# store(filename) : dump to file
17			# restore(filename) : restore from file
18	williamc	1.6	# alias(\@refofkeys,\@aliaskeys) : attatch another set of keys to items that
19			# match the refopfkeys
20			# note that these are references to the arrays
21			# unalias(@aliaskeys) :remove an alias
22	williamc	1.1
23			package Utilities::HashDB;
24	williamc	1.3	use Utilities::DataItem;
25	williamc	1.4	use FileHandle;
26	williamc	1.1	require 5.001;
27
28			sub new {
29			my $class=shift;
30			$self={};
31			bless $self, $class;
32	williamc	1.3	$self->{dataitems}=();
33	williamc	1.1	return $self;
34			}
35
36			sub setdata {
37			my $self=shift;
38			my $data=shift;
39			my @keys=@_;
40
41	williamc	1.3	push @{$self->{dataitems}}, Utilities::DataItem->new($data, @keys);
42	williamc	1.1	}
43
44	williamc	1.6	sub alias {
45			my $self=shift;
46			my $keyref=shift;
47			my $aliaskeys=shift;
48
49			my @objs=$self->match(@{$keyref});
50			foreach $obj ( @objs ) {
51			print "$obj @_\n";
52			$obj->alias(@{$aliaskeys});
53			}
54			}
55
56			sub unalias {
57			my $self=shift;
58			my @keys=@_;
59
60			my @objs=$self->match(@keys);
61			foreach $obj ( @objs ) {
62			$obj->unalias(@_);
63			}
64			}
65
66	williamc	1.1	sub items {
67			my $self=shift;
68	williamc	1.3	return $#{$self->{dataitems}};
69	williamc	1.1	}
70
71	williamc	1.3	sub deletedata {
72			my $self=shift;
73			my @keys=@_;
74
75			# first get all the keys we want to delete
76			my @match=$self->_match(@keys);
77			foreach $i ( @match ) {
78			splice (@{$self->{dataitems}}, $i, 1 );
79			}
80			}
81	williamc	1.1
82	williamc	1.3	sub match {
83	williamc	1.1	my $self=shift;
84			my @keys=@_;
85	williamc	1.3
86	williamc	1.1	my @data=();
87			my @match=$self->_match(@keys);
88	williamc	1.3	foreach $i ( @match ) {
89			push @data, $self->{dataitems}[$i];
90	williamc	1.1	}
91			return @data;
92			}
93
94	williamc	1.3	sub getdata {
95	williamc	1.1	my $self=shift;
96			my @keys=@_;
97	williamc	1.3
98			my @data=();
99	williamc	1.1	my @match=$self->_match(@keys);
100	williamc	1.3	my $i;
101	williamc	1.1	foreach $i ( @match ) {
102	williamc	1.3	push @data, ($self->{dataitems}[$i]->data());
103	williamc	1.1	}
104	williamc	1.3	return @data;
105	williamc	1.4	}
106
107			sub store {
108			my $self=shift;
109			my $filename=shift;
110
111			my $fh=FileHandle->new();
112	williamc	1.6	$fh->autoflush(1);
113	williamc	1.4	open ($fh, ">$filename") or die "Unable to open file $filename\n $!\n";
114			foreach $object ( @{$self->{dataitems}} ) {
115	williamc	1.6	print $fh "\n";
116			$object->store($fh);
117	williamc	1.4	}
118			close $fh;
119			}
120
121			sub restore {
122			my $self=shift;
123			my $filename=shift;
124	williamc	1.5	my @arr=();
125			my $data;
126	williamc	1.4
127			my $fh=FileHandle->new();
128			open ($fh, "<$filename") or die "Unable to open file $filename\n $!\n";
129			while ( <$fh> ) {
130	williamc	1.6	push @{$self->{dataitems}}, Utilities::DataItem->restore($fh);
131	williamc	1.4	}
132			close $fh;
133	williamc	1.1	}
134
135			# ------------------- Support Routines ------------
136			# returns list of array indices of items matching the keys
137	williamc	1.3
138	williamc	1.1	sub _match {
139			my $self=shift;
140			my @keys=@_;
141
142	williamc	1.3	my @matches=();
143			my $data;
144			for ( $i=0; $i<=$#{$self->{dataitems}}; $i++ ) {
145			$data=$self->{dataitems}[$i];
146			if ( $data->match(@keys) ) {
147			push @matches, $i;
148	williamc	1.1	}
149			}
150	williamc	1.3	return @matches;
151	williamc	1.1	}