--- /dev/null
+package LWP::ConnCache;
+
+use strict;
+use vars qw($VERSION $DEBUG);
+
+$VERSION = "5.810";
+
+
+sub new {
+ my($class, %cnf) = @_;
+ my $total_capacity = delete $cnf{total_capacity};
+ $total_capacity = 1 unless defined $total_capacity;
+ if (%cnf && $^W) {
+ require Carp;
+ Carp::carp("Unrecognised options: @{[sort keys %cnf]}")
+ }
+ my $self = bless { cc_conns => [] }, $class;
+ $self->total_capacity($total_capacity);
+ $self;
+}
+
+
+sub deposit {
+ my($self, $type, $key, $conn) = @_;
+ push(@{$self->{cc_conns}}, [$conn, $type, $key, time]);
+ $self->enforce_limits($type);
+ return;
+}
+
+
+sub withdraw {
+ my($self, $type, $key) = @_;
+ my $conns = $self->{cc_conns};
+ for my $i (0 .. @$conns - 1) {
+ my $c = $conns->[$i];
+ next unless $c->[1] eq $type && $c->[2] eq $key;
+ splice(@$conns, $i, 1); # remove it
+ return $c->[0];
+ }
+ return undef;
+}
+
+
+sub total_capacity {
+ my $self = shift;
+ my $old = $self->{cc_limit_total};
+ if (@_) {
+ $self->{cc_limit_total} = shift;
+ $self->enforce_limits;
+ }
+ $old;
+}
+
+
+sub capacity {
+ my $self = shift;
+ my $type = shift;
+ my $old = $self->{cc_limit}{$type};
+ if (@_) {
+ $self->{cc_limit}{$type} = shift;
+ $self->enforce_limits($type);
+ }
+ $old;
+}
+
+
+sub enforce_limits {
+ my($self, $type) = @_;
+ my $conns = $self->{cc_conns};
+
+ my @types = $type ? ($type) : ($self->get_types);
+ for $type (@types) {
+ next unless $self->{cc_limit};
+ my $limit = $self->{cc_limit}{$type};
+ next unless defined $limit;
+ for my $i (reverse 0 .. @$conns - 1) {
+ next unless $conns->[$i][1] eq $type;
+ if (--$limit < 0) {
+ $self->dropping(splice(@$conns, $i, 1), "$type capacity exceeded");
+ }
+ }
+ }
+
+ if (defined(my $total = $self->{cc_limit_total})) {
+ while (@$conns > $total) {
+ $self->dropping(shift(@$conns), "Total capacity exceeded");
+ }
+ }
+}
+
+
+sub dropping {
+ my($self, $c, $reason) = @_;
+ print "DROPPING @$c [$reason]\n" if $DEBUG;
+}
+
+
+sub drop {
+ my($self, $checker, $reason) = @_;
+ if (ref($checker) ne "CODE") {
+ # make it so
+ if (!defined $checker) {
+ $checker = sub { 1 }; # drop all of them
+ }
+ elsif (_looks_like_number($checker)) {
+ my $age_limit = $checker;
+ my $time_limit = time - $age_limit;
+ $reason ||= "older than $age_limit";
+ $checker = sub { $_[3] < $time_limit };
+ }
+ else {
+ my $type = $checker;
+ $reason ||= "drop $type";
+ $checker = sub { $_[1] eq $type }; # match on type
+ }
+ }
+ $reason ||= "drop";
+
+ local $SIG{__DIE__}; # don't interfere with eval below
+ local $@;
+ my @c;
+ for (@{$self->{cc_conns}}) {
+ my $drop;
+ eval {
+ if (&$checker(@$_)) {
+ $self->dropping($_, $reason);
+ $drop++;
+ }
+ };
+ push(@c, $_) unless $drop;
+ }
+ @{$self->{cc_conns}} = @c;
+}
+
+
+sub prune {
+ my $self = shift;
+ $self->drop(sub { !shift->ping }, "ping");
+}
+
+
+sub get_types {
+ my $self = shift;
+ my %t;
+ $t{$_->[1]}++ for @{$self->{cc_conns}};
+ return keys %t;
+}
+
+
+sub get_connections {
+ my($self, $type) = @_;
+ my @c;
+ for (@{$self->{cc_conns}}) {
+ push(@c, $_->[0]) if !$type || ($type && $type eq $_->[1]);
+ }
+ @c;
+}
+
+
+sub _looks_like_number {
+ $_[0] =~ /^([+-]?)(?=\d|\.\d)\d*(\.\d*)?([Ee]([+-]?\d+))?$/;
+}
+
+1;
+
+
+__END__
+
+=head1 NAME
+
+LWP::ConnCache - Connection cache manager
+
+=head1 NOTE
+
+This module is experimental. Details of its interface is likely to
+change in the future.
+
+=head1 SYNOPSIS
+
+ use LWP::ConnCache;
+ my $cache = LWP::ConnCache->new;
+ $cache->deposit($type, $key, $sock);
+ $sock = $cache->withdraw($type, $key);
+
+=head1 DESCRIPTION
+
+The C<LWP::ConnCache> class is the standard connection cache manager
+for LWP::UserAgent.
+
+The following basic methods are provided:
+
+=over
+
+=item $cache = LWP::ConnCache->new( %options )
+
+This method constructs a new C<LWP::ConnCache> object. The only
+option currently accepted is 'total_capacity'. If specified it
+initialize the total_capacity option. It defaults to the value 1.
+
+=item $cache->total_capacity( [$num_connections] )
+
+Get/sets the number of connection that will be cached. Connections
+will start to be dropped when this limit is reached. If set to C<0>,
+then all connections are immediately dropped. If set to C<undef>,
+then there is no limit.
+
+=item $cache->capacity($type, [$num_connections] )
+
+Get/set a limit for the number of connections of the specified type
+that can be cached. The $type will typically be a short string like
+"http" or "ftp".
+
+=item $cache->drop( [$checker, [$reason]] )
+
+Drop connections by some criteria. The $checker argument is a
+subroutine that is called for each connection. If the routine returns
+a TRUE value then the connection is dropped. The routine is called
+with ($conn, $type, $key, $deposit_time) as arguments.
+
+Shortcuts: If the $checker argument is absent (or C<undef>) all cached
+connections are dropped. If the $checker is a number then all
+connections untouched that the given number of seconds or more are
+dropped. If $checker is a string then all connections of the given
+type are dropped.
+
+The $reason argument is passed on to the dropped() method.
+
+=item $cache->prune
+
+Calling this method will drop all connections that are dead. This is
+tested by calling the ping() method on the connections. If the ping()
+method exists and returns a FALSE value, then the connection is
+dropped.
+
+=item $cache->get_types
+
+This returns all the 'type' fields used for the currently cached
+connections.
+
+=item $cache->get_connections( [$type] )
+
+This returns all connection objects of the specified type. If no type
+is specified then all connections are returned. In scalar context the
+number of cached connections of the specified type is returned.
+
+=back
+
+
+The following methods are called by low-level protocol modules to
+try to save away connections and to get them back.
+
+=over
+
+=item $cache->deposit($type, $key, $conn)
+
+This method adds a new connection to the cache. As a result other
+already cached connections might be dropped. Multiple connections with
+the same $type/$key might added.
+
+=item $conn = $cache->withdraw($type, $key)
+
+This method tries to fetch back a connection that was previously
+deposited. If no cached connection with the specified $type/$key is
+found, then C<undef> is returned. There is not guarantee that a
+deposited connection can be withdrawn, as the cache manger is free to
+drop connections at any time.
+
+=back
+
+The following methods are called internally. Subclasses might want to
+override them.
+
+=over
+
+=item $conn->enforce_limits([$type])
+
+This method is called with after a new connection is added (deposited)
+in the cache or capacity limits are adjusted. The default
+implementation drops connections until the specified capacity limits
+are not exceeded.
+
+=item $conn->dropping($conn_record, $reason)
+
+This method is called when a connection is dropped. The record
+belonging to the dropped connection is passed as the first argument
+and a string describing the reason for the drop is passed as the
+second argument. The default implementation makes some noise if the
+$LWP::ConnCache::DEBUG variable is set and nothing more.
+
+=back
+
+=head1 SUBCLASSING
+
+For specialized cache policy it makes sense to subclass
+C<LWP::ConnCache> and perhaps override the deposit(), enforce_limits()
+and dropping() methods.
+
+The object itself is a hash. Keys prefixed with C<cc_> are reserved
+for the base class.
+
+=head1 SEE ALSO
+
+L<LWP::UserAgent>
+
+=head1 COPYRIGHT
+
+Copyright 2001 Gisle Aas.
+
+This library is free software; you can redistribute it and/or
+modify it under the same terms as Perl itself.
projects / dh-make-perl / blobdiff