Net-SNMP-XS/XS.pm

=head1 NAME

Net::SNMP::XS - speed up Net::SNMP by decoding in XS, with limitations

=head1 SYNOPSIS

 use Net::SNMP::XS;

 # loading it is enough, there are no public symbols

=head1 DESCRIPTION

This module tries to speed up Net::SNMP response packet decoding.

It does this by overriding a few selected internal method by (almost)
equivalent XS methods.

This currently reduces decode time by some 70%.

There are currently the following limitations when using this module:

=over 4

=item leading dots are required for iods

=item error handling is currently broken (but parse errors will be detected)

=item oid components are limited to unsigned 32 bit integers

=item translation will be ignored (all values will be delivered "raw")

=back

=cut

package Net::SNMP::XS;

use strict qw(vars subs);
no warnings;

use Guard;

use Net::SNMP::PDU ();
use Net::SNMP::Message ();
use Net::SNMP::MessageProcessing ();

our $VERSION;
our $old_prepare;

BEGIN {
   $VERSION = '0.01';

   $old_prepare = \&Net::SNMP::MessageProcessing::prepare_data_elements;

   # this overrides many methods inside
   require XSLoader;
   XSLoader::load Net::SNMP::XS, $VERSION;
}

sub Net::SNMP::MessageProcessing::prepare_data_elements {
   my ($self, $msg) = @_;

   set_msg $msg, $msg->{_buffer};
   scope_guard \&clr_msg;
   &$old_prepare
}

# almost direct copy from Net::SNMP::Message, as we cannot access $process_methods
{
   package Net::SNMP::Message;

   my @process_methods;

   $process_methods [INTEGER          ] = \&_process_integer32;
   $process_methods [OCTET_STRING     ] = \&_process_octet_string;
   $process_methods [NULL             ] = \&_process_null;
   $process_methods [OBJECT_IDENTIFIER] = \&_process_object_identifier;
   $process_methods [SEQUENCE         ] = \&_process_sequence;
   $process_methods [IPADDRESS        ] = \&_process_ipaddress;
   $process_methods [COUNTER          ] = \&_process_counter;
   $process_methods [GAUGE            ] = \&_process_gauge;
   $process_methods [TIMETICKS        ] = \&_process_timeticks;
   $process_methods [OPAQUE           ] = \&_process_opaque;
   $process_methods [COUNTER64        ] = \&_process_counter64;
   $process_methods [NOSUCHOBJECT     ] = \&_process_nosuchobject;
   $process_methods [NOSUCHINSTANCE   ] = \&_process_nosuchinstance;
   $process_methods [ENDOFMIBVIEW     ] = \&_process_endofmibview;
   $process_methods [GET_REQUEST      ] = \&_process_get_request;
   $process_methods [GET_NEXT_REQUEST ] = \&_process_get_next_request;
   $process_methods [GET_RESPONSE     ] = \&_process_get_response;
   $process_methods [SET_REQUEST      ] = \&_process_set_request;
   $process_methods [TRAP             ] = \&_process_trap;
   $process_methods [GET_BULK_REQUEST ] = \&_process_get_bulk_request;
   $process_methods [INFORM_REQUEST   ] = \&_process_inform_request;
   $process_methods [SNMPV2_TRAP      ] = \&_process_v2_trap;
   $process_methods [REPORT           ] = \&_process_report;

   # should be done in XS
   sub process 
   {
#     my ($this, $expected, $found) = @_;

      return $_[0]->_error if defined($_[0]->{_error});
      return $_[0]->_error unless defined(my $type = _buffer_get($_[0], 1));

      $type = unpack 'C', $type;

      if ($process_methods[$type]) {
         if (@_ >= 2 && (defined $_[1]) && $type != $_[1]) {
            return $_[0]->_error(
               'Expected %s, but found %s', asn1_itoa($_[1]), asn1_itoa($type)
            );
         }
         $_[2] = $type if (@_ == 3);
         $process_methods[$type]->($_[0], $type);
      } else {
         $_[0]->_error('Unknown ASN.1 type [0x%02x]', $type);
      }
   }
}

1;

=head1 AUTHOR

 Marc Lehmann <schmorp@schmorp.de>
 http://home.schmorp.de/

=cut

Revision:	1.1
Committed:	Wed Apr 8 10:30:46 2009 UTC (15 years, 2 months ago) by root
Branch:	MAIN
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	=head1 NAME
2
3			Net::SNMP::XS - speed up Net::SNMP by decoding in XS, with limitations
4
5			=head1 SYNOPSIS
6
7			use Net::SNMP::XS;
8
9			# loading it is enough, there are no public symbols
10
11			=head1 DESCRIPTION
12
13			This module tries to speed up Net::SNMP response packet decoding.
14
15			It does this by overriding a few selected internal method by (almost)
16			equivalent XS methods.
17
18			This currently reduces decode time by some 70%.
19
20			There are currently the following limitations when using this module:
21
22			=over 4
23
24			=item leading dots are required for iods
25
26			=item error handling is currently broken (but parse errors will be detected)
27
28			=item oid components are limited to unsigned 32 bit integers
29
30			=item translation will be ignored (all values will be delivered "raw")
31
32			=back
33
34			=cut
35
36			package Net::SNMP::XS;
37
38			use strict qw(vars subs);
39			no warnings;
40
41			use Guard;
42
43			use Net::SNMP::PDU ();
44			use Net::SNMP::Message ();
45			use Net::SNMP::MessageProcessing ();
46
47			our $VERSION;
48			our $old_prepare;
49
50			BEGIN {
51			$VERSION = '0.01';
52
53			$old_prepare = \&Net::SNMP::MessageProcessing::prepare_data_elements;
54
55			# this overrides many methods inside
56			require XSLoader;
57			XSLoader::load Net::SNMP::XS, $VERSION;
58			}
59
60			sub Net::SNMP::MessageProcessing::prepare_data_elements {
61			my ($self, $msg) = @_;
62
63			set_msg $msg, $msg->{_buffer};
64			scope_guard \&clr_msg;
65			&$old_prepare
66			}
67
68			# almost direct copy from Net::SNMP::Message, as we cannot access $process_methods
69			{
70			package Net::SNMP::Message;
71
72			my @process_methods;
73
74			$process_methods [INTEGER ] = \&_process_integer32;
75			$process_methods [OCTET_STRING ] = \&_process_octet_string;
76			$process_methods [NULL ] = \&_process_null;
77			$process_methods [OBJECT_IDENTIFIER] = \&_process_object_identifier;
78			$process_methods [SEQUENCE ] = \&_process_sequence;
79			$process_methods [IPADDRESS ] = \&_process_ipaddress;
80			$process_methods [COUNTER ] = \&_process_counter;
81			$process_methods [GAUGE ] = \&_process_gauge;
82			$process_methods [TIMETICKS ] = \&_process_timeticks;
83			$process_methods [OPAQUE ] = \&_process_opaque;
84			$process_methods [COUNTER64 ] = \&_process_counter64;
85			$process_methods [NOSUCHOBJECT ] = \&_process_nosuchobject;
86			$process_methods [NOSUCHINSTANCE ] = \&_process_nosuchinstance;
87			$process_methods [ENDOFMIBVIEW ] = \&_process_endofmibview;
88			$process_methods [GET_REQUEST ] = \&_process_get_request;
89			$process_methods [GET_NEXT_REQUEST ] = \&_process_get_next_request;
90			$process_methods [GET_RESPONSE ] = \&_process_get_response;
91			$process_methods [SET_REQUEST ] = \&_process_set_request;
92			$process_methods [TRAP ] = \&_process_trap;
93			$process_methods [GET_BULK_REQUEST ] = \&_process_get_bulk_request;
94			$process_methods [INFORM_REQUEST ] = \&_process_inform_request;
95			$process_methods [SNMPV2_TRAP ] = \&_process_v2_trap;
96			$process_methods [REPORT ] = \&_process_report;
97
98			# should be done in XS
99			sub process
100			{
101			# my ($this, $expected, $found) = @_;
102
103			return $_[0]->_error if defined($_[0]->{_error});
104			return $_[0]->_error unless defined(my $type = _buffer_get($_[0], 1));
105
106			$type = unpack 'C', $type;
107
108			if ($process_methods[$type]) {
109			if (@_ >= 2 && (defined $_[1]) && $type != $_[1]) {
110			return $_[0]->_error(
111			'Expected %s, but found %s', asn1_itoa($_[1]), asn1_itoa($type)
112			);
113			}
114			$_[2] = $type if (@_ == 3);
115			$process_methods[$type]->($_[0], $type);
116			} else {
117			$_[0]->_error('Unknown ASN.1 type [0x%02x]', $type);
118			}
119			}
120			}
121
122			1;
123
124			=head1 AUTHOR
125
126			Marc Lehmann <schmorp@schmorp.de>
127			http://home.schmorp.de/
128
129			=cut
130