Mail::SpamAssassin::AsUseroContributed Perl DoMail::SpamAssassin::AsyncLoop(3)
NAME
Mail::SpamAssassin::AsyncLoop - scanner asynchronous event loop
DESCRIPTION
An asynchronous event loop used for long-running operations, performed
"in the background" during the Mail::SpamAssassin::check() scan
operation, such as DNS blocklist lookups.
METHODS
$ent = $async->start_lookup($ent, $master_deadline)
Register the start of a long-running asynchronous lookup operation.
$ent is a hash reference containing the following items:
key (required)
A key string, unique to this lookup. This is what is reported
in debug messages, used as the key for "get_lookup()", etc.
id (required)
An ID string, also unique to this lookup. Typically, this is
the DNS packet ID as returned by DnsResolver's "bgsend" method.
Sadly, the Net::DNS architecture forces us to keep a separate
ID string for this task instead of reusing "key" -- if you are
not using DNS lookups through DnsResolver, it should be OK to
just reuse "key".
type (required)
A string, typically one word, used to describe the type of
lookup in log messages, such as "DNSBL", "MX", "TXT".
zone (optional)
A zone specification (typically a DNS zone name - e.g. host,
domain, or RBL) which may be used as a key to look up per-zone
settings. No semantics on this parameter is imposed by this
module. Currently used to fetch by-zone timeouts.
timeout_initial (optional)
An initial value of elapsed time for which we are willing to
wait for a response (time in seconds, floating point value is
allowed). When elapsed time since a query started exceeds the
timeout value and there are no other queries to wait for, the
query is aborted. The actual timeout value ranges from
timeout_initial and gradually approaches timeout_min (see next
parameter) as the number of already completed queries
approaches the number of all queries started.
If a caller does not explicitly provide this parameter or its
value is undefined, a default initial timeout value is settable
by a configuration variable rbl_timeout.
If a value of the timeout_initial parameter is below
timeout_min, the initial timeout is set to timeout_min.
timeout_min (optional)
A lower bound (in seconds) to which the actual timeout
approaches as the number of queries completed approaches the
number of all queries started. Defaults to 0.2 *
timeout_initial.
$ent is returned by this method, with its contents augmented by
additional information.
$ent = $async->bgsend_and_start_lookup($domain, $type, $class, $ent,
$cb, %options)
A common idiom: calls "bgsend", followed by a call to
"start_lookup", returning the argument $ent object as modified by
"start_lookup" and filled-in with a query ID.
$ent = $async->get_lookup($key)
Retrieve the pending-lookup object for the given key $key.
If the lookup is complete, this will return "undef".
Note that a lookup is still considered "pending" until
"complete_lookups()" is called, even if it has been reported as
complete via "set_response_packet()".
$async->log_lookups_timing()
Log sorted timing for all completed lookups.
$alldone = $async->complete_lookups()
Perform a poll of the pending lookups, to see if any are completed.
Callbacks on completed queries will be called from
poll_responses().
If there are no lookups remaining, or if too much time has elapsed
since any results were returned, 1 is returned, otherwise 0.
$async->abort_remaining_lookups()
Abort any remaining lookups.
$async->set_response_packet($id, $pkt, $key, $timestamp)
Register a "response packet" for a given query. $id is the ID for
the query, and must match the "id" supplied in "start_lookup()".
$pkt is the packet object for the response. A parameter $key
identifies an entry in a hash %{$self->{pending_lookups}} where the
object which spawned this query can be found, and through which
futher information about the query is accessible.
$pkt may be undef, indicating that no response packet is available,
but a query has completed (e.g. was aborted or dismissed) and is no
longer "pending".
The DNS resolver's response packet $pkt will be made available to a
callback subroutine through its argument as well as in
"$ent-<gt"{response_packet}>.
$async->report_id_complete($id,$key,$key,$timestamp)
Legacy. Equivalent to
$self->set_response_packet($id,undef,$key,$timestamp), i.e.
providing undef as a response packet. Register that a query has
completed and is no longer "pending". $id is the ID for the query,
and must match the "id" supplied in "start_lookup()".
One or the other of "set_response_packet()" or
"report_id_complete()" should be called, but not both.
$time = $async->last_poll_responses_time()
Get the time of the last call to "poll_responses()" (which is
called from "complete_lookups()". If "poll_responses()" was never
called or "abort_remaining_lookups()" has been called
"last_poll_responses_time()" will return undef.
perl v5.16.3 2014-02-07 Mail::SpamAssassin::AsyncLoop(3)