/usr/share/perl5/LWP/ConnCache.pm is in libwww-perl 6.04-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 | package LWP::ConnCache;
use strict;
use vars qw($VERSION $DEBUG);
$VERSION = "6.02";
sub new {
my($class, %cnf) = @_;
my $total_capacity = 1;
if (exists $cnf{total_capacity}) {
$total_capacity = delete $cnf{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.
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