src/URL/URLhandler.pm

# url handler -> returns the location of the file
# Interface
# ---------
# new(cache)       : A new urlhandler with a defined default cahce directory
# download(url,[location]) : as get but always download
# get(url,[location]) : download from the specified url to cache or location
#                       return the full url path name incl. any base expansion
#                       and the filename downloaded to
# setbase(type,variablehash) : set the url defaults for a specific url type
#                              arguments are dependent on type
# unsetbase(type)  : deactivate a previously set base
# currentbase(type) : return the current base for the given type
#
# ----------------------------------------------------------------------

package URL::URLhandler;
require 5.004;
use Utilities::AddDir;
use URL::URLcache;
use URL::URLclass;
use URL::URLbase;
use Carp;

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

sub init {
        use Utilities::AddDir;
        my $self=shift;
        my $cache=shift;
        $self->{cache}=$cache;
        $self->{dummybase}=URL::URLbase->new({});
        $self->{cachestore}=$self->{cache}->filestore();
        use URL::URL_cvs;
        use URL::URL_cvsfile;
        use URL::URL_file;
        use URL::URL_filed;
        $self->{urlmodules}={
                        'cvsfile' => 'URL::URL_cvsfile',
                        'cvs' => 'URL::URL_cvs',
                        'file' => 'URL::URL_file',
                        'filed' => 'URL::URL_filed'
                };
}

sub get {
        my $self=shift;
        my $origurl=shift;
        my $file="";

        my $url=URL::URLclass->new($origurl);
        my $type=$url->type();
        $url->expandurl($self->currentbase($type));
        my $fullurl=$url->url();

        my $location=$self->{cache}->file($fullurl);
        if ( $location ne "" ) {
          $file=$self->{cache}->file($location);
          #print " Already defined file --".$location." -- ".$file."\n";
        }
        else {
          ($fullurl,$file)=$self->download($origurl, @_);
        }
        return ($fullurl, $file);
}

sub download {
        my $self=shift;
        my $origurl=shift;

        print "downloading $origurl\n";
        # Process the URL string
        my $url=URL::URLclass->new($origurl);
        my $type=$url->type();
        $urltypehandler=$self->_typehandler($type);
        $url->expandurl($self->currentbase($type));

        # Generate a location name if not provided 
        if ( @_ ) {
           $location=shift;
        }
        else {
           $location=$self->{cache}->filename($url->url());
        }
        # -- get the file from the appropriate handler
        if ( defined $urltypehandler ) {
             # Call the download module
             $file=eval{$urltypehandler->get($url, $location)}; 
        } 

        # now register it in the cache if successful
        if ( $file ) {
          $self->{cache}->store($url->url(), $location);
          $self->{cache}->store($location, $file);
        }
        return ($url->url(), $file);
}

sub setbase {
        my $self=shift;
        my $type=shift;
        my @args=@_;
        my $oref;

        $self->checktype($type);
        # make a new base object
        my $base=URL::URLbase->new(@_);
        push @{$self->{"basestack"}{$type}}, $base;
}

sub unsetbase {
        my $self=shift;
        my $type=shift;
        my $oref;

        $self->checktype($type);
        # pop off the stack and call the unset base method
        if ( $#{$self->{basestack}{$type}} >=0 ) {
           my $base=pop @{$self->{basestack}{$type}};
           undef $base;
        }
        else {
           die "URLhandler error: Unable to unset type $type\n";
        }
        # remove the stack if its empty
        if ( $#{$self->{basestack}{$type}} == -1 ) {
          delete $self->{basestack}{$type};
        }
}

sub currentbase {
        my $self=shift;
        my $type=shift;
        my $rv;

        if ( exists $self->{basestack}{$type} ) {
          $rv=${$self->{basestack}{$type}}[$#{$self->{basestack}{$type}}];
        }
        else {
          $rv=$self->{dummybase};
        }
        return $rv;
}

sub checktype($type) {
        my $self=shift;
        my $type=shift;

        # Check type is supported
        if ( ! exists $self->{urlmodules}{$type} ) {
          die "URLhandler error: Unsupported type $type\n";
        }
}

sub _typehandler {
        my $self=shift;
        my $type=shift;

        $self->checktype($type);

        # instantiate only if it dosnt already exist;
        if ( exists $self->{'urlobjs'}{$type} ) {
                $self->{'urlobjs'}{$type};
        }       
        else {
                $self->{'urlobjs'}{$type}=$self->{urlmodules}{$type}->new();
        }
}
Revision:	1.11
Committed:	Wed Nov 17 19:14:38 1999 UTC (25 years, 5 months ago) by williamc
Content type:	text/plain
Branch:	MAIN
Changes since 1.10:	+28 -4 lines
Log Message:	New download function with get returning from cache
#	User	Rev	Content
1	williamc	1.7	# url handler -> returns the location of the file
2			# Interface
3	williamc	1.1	# ---------
4	williamc	1.7	# new(cache) : A new urlhandler with a defined default cahce directory
5	williamc	1.11	# download(url,[location]) : as get but always download
6	williamc	1.9	# get(url,[location]) : download from the specified url to cache or location
7			# return the full url path name incl. any base expansion
8			# and the filename downloaded to
9	williamc	1.4	# setbase(type,variablehash) : set the url defaults for a specific url type
10	williamc	1.7	# arguments are dependent on type
11	williamc	1.1	# unsetbase(type) : deactivate a previously set base
12	williamc	1.9	# currentbase(type) : return the current base for the given type
13	williamc	1.1	#
14			# ----------------------------------------------------------------------
15
16	williamc	1.5	package URL::URLhandler;
17	williamc	1.1	require 5.004;
18			use Utilities::AddDir;
19	williamc	1.9	use URL::URLcache;
20			use URL::URLclass;
21			use URL::URLbase;
22	williamc	1.1	use Carp;
23
24			sub new {
25			my $class=shift;
26			my $cache=shift;
27			$self={};
28			bless $self, $class;
29			$self->init($cache);
30			return $self;
31			}
32
33			sub init {
34			use Utilities::AddDir;
35			my $self=shift;
36			my $cache=shift;
37			$self->{cache}=$cache;
38	williamc	1.9	$self->{dummybase}=URL::URLbase->new({});
39	williamc	1.7	$self->{cachestore}=$self->{cache}->filestore();
40	williamc	1.2	use URL::URL_cvs;
41	williamc	1.5	use URL::URL_cvsfile;
42	williamc	1.2	use URL::URL_file;
43	williamc	1.7	use URL::URL_filed;
44	williamc	1.2	$self->{urlmodules}={
45	williamc	1.5	'cvsfile' => 'URL::URL_cvsfile',
46			'cvs' => 'URL::URL_cvs',
47	williamc	1.7	'file' => 'URL::URL_file',
48			'filed' => 'URL::URL_filed'
49	williamc	1.2	};
50	williamc	1.1	}
51
52	williamc	1.7	sub get {
53	williamc	1.4	my $self=shift;
54	williamc	1.9	my $origurl=shift;
55	williamc	1.11	my $file="";
56	williamc	1.9
57	williamc	1.11	my $url=URL::URLclass->new($origurl);
58			my $type=$url->type();
59			$url->expandurl($self->currentbase($type));
60			my $fullurl=$url->url();
61
62			my $location=$self->{cache}->file($fullurl);
63			if ( $location ne "" ) {
64			$file=$self->{cache}->file($location);
65			#print " Already defined file --".$location." -- ".$file."\n";
66			}
67			else {
68			($fullurl,$file)=$self->download($origurl, @_);
69			}
70			return ($fullurl, $file);
71			}
72
73			sub download {
74			my $self=shift;
75			my $origurl=shift;
76
77			print "downloading $origurl\n";
78			# Process the URL string
79			my $url=URL::URLclass->new($origurl);
80	williamc	1.9	my $type=$url->type();
81			$urltypehandler=$self->_typehandler($type);
82			$url->expandurl($self->currentbase($type));
83
84			# Generate a location name if not provided
85			if ( @_ ) {
86			$location=shift;
87			}
88			else {
89			$location=$self->{cache}->filename($url->url());
90			}
91	williamc	1.11	# -- get the file from the appropriate handler
92	williamc	1.9	if ( defined $urltypehandler ) {
93			# Call the download module
94			$file=eval{$urltypehandler->get($url, $location)};
95			}
96	williamc	1.4
97	williamc	1.9	# now register it in the cache if successful
98			if ( $file ) {
99	williamc	1.11	$self->{cache}->store($url->url(), $location);
100			$self->{cache}->store($location, $file);
101	williamc	1.9	}
102	williamc	1.10	return ($url->url(), $file);
103	williamc	1.4	}
104
105	williamc	1.9	sub setbase {
106	williamc	1.1	my $self=shift;
107	williamc	1.9	my $type=shift;
108			my @args=@_;
109			my $oref;
110	williamc	1.7
111	williamc	1.9	$self->checktype($type);
112			# make a new base object
113			my $base=URL::URLbase->new(@_);
114	williamc	1.10	push @{$self->{"basestack"}{$type}}, $base;
115	williamc	1.9	}
116	williamc	1.1
117	williamc	1.9	sub unsetbase {
118			my $self=shift;
119			my $type=shift;
120			my $oref;
121	williamc	1.7
122	williamc	1.9	$self->checktype($type);
123			# pop off the stack and call the unset base method
124			if ( $#{$self->{basestack}{$type}} >=0 ) {
125			my $base=pop @{$self->{basestack}{$type}};
126			undef $base;
127			}
128			else {
129			die "URLhandler error: Unable to unset type $type\n";
130	williamc	1.4	}
131	williamc	1.10	# remove the stack if its empty
132			if ( $#{$self->{basestack}{$type}} == -1 ) {
133			delete $self->{basestack}{$type};
134			}
135	williamc	1.1	}
136
137	williamc	1.9	sub currentbase {
138	williamc	1.1	my $self=shift;
139			my $type=shift;
140	williamc	1.9	my $rv;
141	williamc	1.1
142	williamc	1.9	if ( exists $self->{basestack}{$type} ) {
143	williamc	1.10	$rv=${$self->{basestack}{$type}}[$#{$self->{basestack}{$type}}];
144	williamc	1.1	}
145			else {
146	williamc	1.9	$rv=$self->{dummybase};
147	williamc	1.1	}
148	williamc	1.9	return $rv;
149	williamc	1.1	}
150
151	williamc	1.9	sub checktype($type) {
152	williamc	1.1	my $self=shift;
153	williamc	1.9	my $type=shift;
154	williamc	1.1
155	williamc	1.9	# Check type is supported
156	williamc	1.2	if ( ! exists $self->{urlmodules}{$type} ) {
157	williamc	1.9	die "URLhandler error: Unsupported type $type\n";
158	williamc	1.1	}
159			}
160
161	williamc	1.9	sub _typehandler {
162	williamc	1.7	my $self=shift;
163	williamc	1.8	my $type=shift;
164	williamc	1.7
165	williamc	1.9	$self->checktype($type);
166	williamc	1.7
167	williamc	1.9	# instantiate only if it dosnt already exist;
168	williamc	1.10	if ( exists $self->{'urlobjs'}{$type} ) {
169			$self->{'urlobjs'}{$type};
170			}
171			else {
172			$self->{'urlobjs'}{$type}=$self->{urlmodules}{$type}->new();
173			}
174	williamc	1.1	}