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docs::api::Apache2::Connection

Section: User Contributed Perl Documentation (3)
Updated: 2005-10-20
Index Return to Main Contents
 

NAME

Apache2::Connection - Perl API for Apache connection object  

Synopsis

  use Apache2::Connection ();

  # is connection still open?
  $status = $c->aborted;

  # base server
  $base_server = $c->base_server();

  # needed for creating buckets/brigades
  $ba = $c->bucket_alloc();

  # client's socket
  $socket = $c->client_socket;

  # unique connection id
  $id = $c->id();

  # connection filters stack
  $input_filters = $c->input_filters();
  $output_filters = $c->output_filters();

  # keep the connection alive?
  $status = $c->keepalive();

  # how many requests served over the current connection
  $served = $c->keepalives();

  # this connection's local and remote socket addresses
  $local_sa  = $c->local_addr();
  $remote_sa = $c->remote_addr();

  # local and remote hostnames
  $local_host = $c->local_host();
  $remote_host = $c->get_remote_host();
  $remote_host = $c->remote_host();

  # server and remote client's IP addresses
  $local_ip = $c->local_ip();
  $remote_ip = $c->remote_ip();

  # connection level Apache notes
  $notes = $c->notes();

  # this connection's pool
  $p = $c->pool();

 

Description

"Apache2::RequestRec" provides the Perl API for Apache connection record object.  

API

"Apache2::Connection" provides the following functions and/or methods:  

aborted

Check whether the connection is still open

  $status = $c->aborted();

obj: $c ( Apache2::Connection object )
ret: $status ( boolean )
true if the connection has been aborted, false if still open
since: 2.0.00
 

base_server

Physical server this connection came in on (main server or vhost):

  $base_server = $c->base_server();

obj: $c ( Apache2::Connection object )
ret: $base_server ( Apache2::Server object )
since: 2.0.00
 

bucket_alloc

The bucket allocator to use for all bucket/brigade creations

  $ba = $c->bucket_alloc();

obj: $c ( Apache2::Connection object )
ret: $ba ( APR::BucketAlloc object )
since: 2.0.00

This object is needed by "APR::Bucket" and "APR::Brigade" methods/functions.  

client_socket

Get/set the client socket

  $socket      = $c->client_socket;
  $prev_socket = $c->client_socket($new_socket);

obj: $c ( Apache2::Connection object )
opt arg1: $new_socket ( APR::Socket object object )
If passed a new socket will be set.
ret: $socket ( APR::Socket object object )
current client socket

if the optional argument $new_socket was passed the previous socket object is returned.

since: 2.0.00
 

get_remote_host

Lookup the client's DNS hostname or IP address

  $remote_host = $c->remote_host();
  $remote_host = $c->remote_host($type);
  $remote_host = $c->remote_host($type, $dir_config);

obj: $c ( Apache2::Connection object )
The current connection
opt arg1: $type ( :remotehost constant )
The type of lookup to perform:
Apache2::Const::REMOTE_DOUBLE_REV
will always force a DNS lookup, and also force a double reverse lookup, regardless of the "HostnameLookups" setting. The result is the (double reverse checked) hostname, or undef if any of the lookups fail.
Apache2::Const::REMOTE_HOST
returns the hostname, or "undef" if the hostname lookup fails. It will force a DNS lookup according to the "HostnameLookups" setting.
Apache2::Const::REMOTE_NAME
returns the hostname, or the dotted quad if the hostname lookup fails. It will force a DNS lookup according to the "HostnameLookups" setting.
Apache2::Const::REMOTE_NOLOOKUP
is like "Apache2::Const::REMOTE_NAME" except that a DNS lookup is never forced.

Default value is "Apache2::Const::REMOTE_NAME".

opt arg2: $dir_config ( Apache2::ConfVector object )
The directory config vector from the request. It's needed to find the container in which the directive "HostnameLookups" is set. To get one for the current request use "$r->per_dir_config".

By default, "undef" is passed, in which case it's the same as if "HostnameLookups" was set to "Off".

ret: $remote_host ( string/undef )
The remote hostname. If the configuration directive HostNameLookups is set to off, this returns the dotted decimal representation of the client's IP address instead. Might return "undef" if the hostname is not known.
since: 2.0.00

The result of "get_remote_host" call is cached in "$c->remote_host". If the latter is set, "get_remote_host" will return that value immediately, w/o doing any checkups.  

id

ID of this connection; unique at any point in time

  $id = $c->id();

obj: $c ( Apache2::Connection object )
ret: $id (integer)
since: 2.0.00
 

input_filters

Get/set the first filter in a linked list of protocol level input filters:

  $input_filters      = $c->input_filters();
  $prev_input_filters = $c->input_filters($new_input_filters);

obj: $c ( Apache2::Connection object )
opt arg1: $new_input_filters
Set a new value
ret: $input_filters ( Apache2::Filter object )
The first filter in the connection input filters chain.

If $new_input_filters was passed, returns the previous value.

since: 2.0.00

For an example see: Bucket Brigades-based Protocol Module  

keepalive

This method answers the question: Should the the connection be kept alive for another HTTP request after the current request is completed?

  $status = $c->keepalive();
  $status = $c->keepalive($new_status);

obj: $c ( Apache2::Connection object )
opt arg1: $new_status ( :conn_keepalive constant )
Normally you should not mess with setting this option when handling the HTTP protocol. If you do (for example when sending your own headers set with "$r->assbackwards") --- take a look at the ap_set_keepalive() function in httpd-2.0/modules/http/http_protocol.c.
ret: $status ( :conn_keepalive constant )
The method does not return true or false, but one of the states which can be compared against (":conn_keepalive constants").
since: 2.0.00

Unless you set this value yourself when implementing non-HTTP protocols, it's only relevant for HTTP requests.

For example:

  use Apache2::RequestRec ();
  use Apache2::Connection ();

  use Apache2::Const -compile => qw(:conn_keepalive);
  ...
  my $c = $r->connection;
  if ($c->keepalive == Apache2::Const::CONN_KEEPALIVE) {
      # do something
  }
  elsif ($c->keepalive == Apache2::Const::CONN_CLOSE) {
      # do something else
  }
  elsif ($c->keepalive == Apache2::Const::CONN_UNKNOWN) {
      # do yet something else
  }
  else {
      # die "unknown state";
  }

Notice that new states could be added later by Apache, so your code should make no assumptions and do things only if the desired state matches.  

keepalives

How many requests were already served over the current connection.

  $served = $c->keepalives();
  $served = $c->keepalives($new_served);

obj: $c ( Apache2::Connection object )
opt arg1: $new_served (integer)
Set the number of served requests over the current connection. Normally you won't do that when handling HTTP requests. (But see below a note regarding "$r->assbackwards").
ret: $served (integer)
How many requests were already served over the current connection.

In most handlers, but HTTP output filter handlers, that value doesn't count the current request. For the latter it'll count the current request.

since: 2.0.00

This method is only relevant for keepalive connections. The core connection output filter "ap_http_header_filter" increments this value when the response headers are sent and it decides that the connection should not be closed (see "ap_set_keepalive()").

If you send your own set of HTTP headers with "$r->assbackwards", which includes the "Keep-Alive" HTTP response header, you must make sure to increment the "keepalives" counter.  

local_addr

Get this connection's local socket address

  $local_sa = $c->local_addr();

obj: $c ( Apache2::Connection object )
ret: $local_sa ( APR::SockAddr object )
since: 2.0.00
 

local_host

used for ap_get_server_name when UseCanonicalName is set to DNS (ignores setting of HostnameLookups)

  $local_host = $c->local_host();

obj: $c ( Apache2::Connection object )
ret: $local_host (string)
since: 2.0.00

META: you probably shouldn't use this method, but ( "get_server_name" ) if inside request and $r is available.  

local_ip

server IP address

  $local_ip = $c->local_ip();

obj: $c ( Apache2::Connection object )
ret: $local_ip (string)
since: 2.0.00
 

notes

Get/set text notes for the duration of this connection. These notes can be passed from one module to another (not only mod_perl, but modules in any other language):

  $notes      = $c->notes();
  $prev_notes = $c->notes($new_notes);

obj: $c ( Apache2::Connection object )
opt arg1: $new_notes ( APR::Table object )
ret: $notes ( APR::Table object )
the current notes table.

if the $new_notes argument was passed, returns the previous value.

since: 2.0.00

Also see "$r->notes"  

output_filters

Get the first filter in a linked list of protocol level output filters:

  $output_filters = $c->output_filters();
  $prev_output_filters = $r->output_filters($new_output_filters);

obj: $c ( Apache2::Connection object )
opt arg1: $new_output_filters
Set a new value
ret: $output_filters ( Apache2::Filter object )
The first filter in the connection output filters chain.

If $new_output_filters was passed, returns the previous value.

since: 2.0.00

For an example see: Bucket Brigades-based Protocol Module  

pool

Pool associated with this connection

  $p = $c->pool();

obj: $c ( Apache2::Connection object )
ret: $p ( APR::Pool object )
since: 2.0.00
 

remote_addr

Get this connection's remote socket address

  $remote_sa = $c->remote_addr();

obj: $c ( Apache2::Connection object )
ret: $remote_sa ( APR::SockAddr object )
since: 2.0.00
 

remote_ip

Client's IP address

  $remote_ip      = $c->remote_ip();
  $prev_remote_ip = $c->remote_ip($new_remote_ip);

obj: $c ( Apache2::Connection object )
opt arg1: $new_remote_ip ( string )
If passed a new value will be set
ret: $remote_ip ( string )
current remote ip address

if the optional argument $new_remote_ip was passed the previous value is returned.

since: 2.0.00
 

remote_host

Client's DNS name:

  $remote_host = $c->remote_host();

obj: $c ( Apache2::Connection object )
ret: $remote_host ( string/undef )
If "$c->get_remote_host" was run it returns the cached value, which is a client DNS name or "" if it wasn't found. If the check wasn't run --- "undef" is returned.
since: 2.0.00

It's best to to call "$c->get_remote_host" instead of directly accessing this variable.  

Unsupported API

"Apache2::Connection" also provides auto-generated Perl interface for a few other methods which aren't tested at the moment and therefore their API is a subject to change. These methods will be finalized later as a need arises. If you want to rely on any of the following methods please contact the the mod_perl development mailing list so we can help each other take the steps necessary to shift the method to an officially supported API.  

conn_config

Config vector containing pointers to connections per-server config structures

  $ret = $c->conn_config();

obj: $c ( Apache2::Connection object )
ret: $ret ( Apache2::ConfVector object )
since: 2.0.00
 

sbh

META: Autogenerated - needs to be reviewed/completed

handle to scoreboard information for this connection

  $sbh = $c->sbh();

obj: $c ( Apache2::Connection object )
ret: $sbh (XXX)
since: 2.0.00

META: Not sure how this can be used from mod_perl at the moment. Unless "Apache2::Scoreboard" is extended to provide a hook to read from this variable.  

See Also

mod_perl 2.0 documentation.  

Copyright

mod_perl 2.0 and its core modules are copyrighted under The Apache Software License, Version 2.0.  

Authors

The mod_perl development team and numerous contributors.


 

Index

NAME
Synopsis
Description
API
aborted
base_server
bucket_alloc
client_socket
get_remote_host
id
input_filters
keepalive
keepalives
local_addr
local_host
local_ip
notes
output_filters
pool
remote_addr
remote_ip
remote_host
Unsupported API
conn_config
sbh
See Also
Copyright
Authors

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