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 a factor of ten for typical bulk
responses.

There are currently the following limitations when using this module:

=over 4

=item overriding internal functions might cause the module to
malfunction with future versions of Net::SNMP

=item only leading dots for oids are supported

=item error messages will be simpler/different

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

=item a moderately modern (>= C99) C compiler is required

=item only tested with 5.10, no intentions to port to older perls

=item duplicate OIDs are not supported

=item REPORT PDUs are not supported

=back

=cut

package Net::SNMP::XS;

use strict qw(vars subs);
no warnings;

use Guard;

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

our $VERSION;
our $old_prepare;

BEGIN {
   $VERSION = '0.02';

   $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
}

package Net::SNMP::Message;

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

package Net::SNMP::PDU;

# var_bind_list hardcodes oid_lext_sort. *sigh*
# we copy it 1:1, except for using oid_lex_sort.

sub var_bind_list
{
   my ($this, $vbl, $types) = @_;

   return if defined($this->{_error});

   if (@_ > 1) {
      # The VarBindList HASH is being updated from an external
      # source.  We need to update the VarBind names ARRAY to
      # correspond to the new keys of the HASH.  If the updated
      # information is valid, we will use lexicographical ordering
      # for the ARRAY entries since we do not have a PDU to use
      # to determine the ordering.  The ASN.1 types HASH is also
      # updated here if a cooresponding HASH is passed.  We double
      # check the mapping by populating the hash with the keys of
      # the VarBindList HASH. 

      if (!defined($vbl) || (ref($vbl) ne 'HASH')) {

         $this->{_var_bind_list}  = undef;
         $this->{_var_bind_names} = [];
         $this->{_var_bind_types} = undef; 

      } else {

         $this->{_var_bind_list} = $vbl;

         @{$this->{_var_bind_names}} = Net::SNMP::oid_lex_sort keys %$vbl;

         if (!defined($types) || (ref($types) ne 'HASH')) {
             $types = {};
         }

         map { 
            $this->{_var_bind_types}->{$_} = 
               exists($types->{$_}) ? $types->{$_} : undef; 
         } keys(%{$vbl});

      }

   }

   $this->{_var_bind_list};
}

1;

=head1 AUTHOR

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

=cut

Revision:	1.8
Committed:	Sat Apr 11 06:24:18 2009 UTC (15 years, 2 months ago) by root
Branch:	MAIN
Changes since 1.7:	+73 -26 lines
Log Message:	* empty log message *
#	Content
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 a factor of ten for typical bulk
19	responses.
20
21	There are currently the following limitations when using this module:
22
23	=over 4
24
25	=item overriding internal functions might cause the module to
26	malfunction with future versions of Net::SNMP
27
28	=item only leading dots for oids are supported
29
30	=item error messages will be simpler/different
31
32	=item translation will be ignored (all values will be delivered "raw")
33
34	=item a moderately modern (>= C99) C compiler is required
35
36	=item only tested with 5.10, no intentions to port to older perls
37
38	=item duplicate OIDs are not supported
39
40	=item REPORT PDUs are not supported
41
42	=back
43
44	=cut
45
46	package Net::SNMP::XS;
47
48	use strict qw(vars subs);
49	no warnings;
50
51	use Guard;
52
53	use Net::SNMP ();
54	use Net::SNMP::PDU ();
55	use Net::SNMP::Message ();
56	use Net::SNMP::MessageProcessing ();
57
58	our $VERSION;
59	our $old_prepare;
60
61	BEGIN {
62	$VERSION = '0.02';
63
64	$old_prepare = \&Net::SNMP::MessageProcessing::prepare_data_elements;
65
66	# this overrides many methods inside
67	require XSLoader;
68	XSLoader::load Net::SNMP::XS, $VERSION;
69	}
70
71	sub Net::SNMP::MessageProcessing::prepare_data_elements {
72	my ($self, $msg) = @_;
73
74	set_msg $msg, $msg->{_buffer};
75	scope_guard \&clr_msg;
76	&$old_prepare
77	}
78
79	package Net::SNMP::Message;
80
81	Net::SNMP::XS::set_type INTEGER , \&_process_integer32;
82	Net::SNMP::XS::set_type OCTET_STRING , \&_process_octet_string;
83	Net::SNMP::XS::set_type NULL , \&_process_null;
84	Net::SNMP::XS::set_type OBJECT_IDENTIFIER, \&_process_object_identifier;
85	Net::SNMP::XS::set_type SEQUENCE , \&_process_sequence;
86	Net::SNMP::XS::set_type IPADDRESS , \&_process_ipaddress;
87	Net::SNMP::XS::set_type COUNTER , \&_process_counter;
88	Net::SNMP::XS::set_type GAUGE , \&_process_gauge;
89	Net::SNMP::XS::set_type TIMETICKS , \&_process_timeticks;
90	Net::SNMP::XS::set_type OPAQUE , \&_process_opaque;
91	Net::SNMP::XS::set_type COUNTER64 , \&_process_counter64;
92	Net::SNMP::XS::set_type NOSUCHOBJECT , \&_process_nosuchobject;
93	Net::SNMP::XS::set_type NOSUCHINSTANCE , \&_process_nosuchinstance;
94	Net::SNMP::XS::set_type ENDOFMIBVIEW , \&_process_endofmibview;
95	Net::SNMP::XS::set_type GET_REQUEST , \&_process_get_request;
96	Net::SNMP::XS::set_type GET_NEXT_REQUEST , \&_process_get_next_request;
97	Net::SNMP::XS::set_type GET_RESPONSE , \&_process_get_response;
98	Net::SNMP::XS::set_type SET_REQUEST , \&_process_set_request;
99	Net::SNMP::XS::set_type TRAP , \&_process_trap;
100	Net::SNMP::XS::set_type GET_BULK_REQUEST , \&_process_get_bulk_request;
101	Net::SNMP::XS::set_type INFORM_REQUEST , \&_process_inform_request;
102	Net::SNMP::XS::set_type SNMPV2_TRAP , \&_process_v2_trap;
103	Net::SNMP::XS::set_type REPORT , \&_process_report;
104
105	package Net::SNMP::PDU;
106
107	# var_bind_list hardcodes oid_lext_sort. sigh
108	# we copy it 1:1, except for using oid_lex_sort.
109
110	sub var_bind_list
111	{
112	my ($this, $vbl, $types) = @_;
113
114	return if defined($this->{_error});
115
116	if (@_ > 1) {
117	# The VarBindList HASH is being updated from an external
118	# source. We need to update the VarBind names ARRAY to
119	# correspond to the new keys of the HASH. If the updated
120	# information is valid, we will use lexicographical ordering
121	# for the ARRAY entries since we do not have a PDU to use
122	# to determine the ordering. The ASN.1 types HASH is also
123	# updated here if a cooresponding HASH is passed. We double
124	# check the mapping by populating the hash with the keys of
125	# the VarBindList HASH.
126
127	if (!defined($vbl) \|\| (ref($vbl) ne 'HASH')) {
128
129	$this->{_var_bind_list} = undef;
130	$this->{_var_bind_names} = [];
131	$this->{_var_bind_types} = undef;
132
133	} else {
134
135	$this->{_var_bind_list} = $vbl;
136
137	@{$this->{_var_bind_names}} = Net::SNMP::oid_lex_sort keys %$vbl;
138
139	if (!defined($types) \|\| (ref($types) ne 'HASH')) {
140	$types = {};
141	}
142
143	map {
144	$this->{_var_bind_types}->{$_} =
145	exists($types->{$_}) ? $types->{$_} : undef;
146	} keys(%{$vbl});
147
148	}
149
150	}
151
152	$this->{_var_bind_list};
153	}
154
155	1;
156
157	=head1 AUTHOR
158
159	Marc Lehmann <schmorp@schmorp.de>
160	http://home.schmorp.de/
161
162	=cut
163