Mail::Box::Thread::ManUser(Contributed Perl DocumMail::Box::Thread::Manager(3)NAMEMail::Box::Thread::Manager - maintain threads within a set of folders
INHERITANCEMail::Box::Thread::Manager
is a Mail::Reporter
SYNOPSIS
my $mgr = Mail::Box::Thread::Manager->new;
my $folder = $mgr->open(folder => '/tmp/inbox');
my $threads = $mgr->threads(folder => $folder);
my $threads = $mgr->threads($folder); # same
foreach my $thread ($threads->all) {
$thread->print;
}
$threads->includeFolder($folder);
$threads->removeFolder($folder);
DESCRIPTION
A (message-)thread is a message with links to messages which followed
in reply of that message. And then the messages with replied to the
messages, which replied the original message. And so on. Some threads
are only one message long (never replied to), some threads are very
long.
The "Mail::Box::Thread::Manager" is very powerful. Not only is it able
to do a descent job on MH-like folders (makes a trade-off between
perfection and speed), it also can maintain threads from messages
residing in different opened folders. Both facilities are rare for
mail-agents. The manager creates flexible trees with
Mail::Box::Thread::Node objects.
METHODS
Constructors
Mail::Box::Thread::Manager->new(OPTIONS)
A "Mail::Box::Thread::Manager" object is usually created by a
Mail::Box::Manager. One manager can produce more than one of these
objects. One thread manager can combine messages from a set of
folders, which may be partially overlapping with other objects of
the same type.
-Option --Defined in --Default
dummy_type Mail::Message::Dummy
folder [ ]
folders [ ]
log Mail::Reporter 'WARNINGS'
thread_body <false>
thread_type Mail::Box::Thread::Node
timespan '3 days'
trace Mail::Reporter 'WARNINGS'
window 10
dummy_type => CLASS
The type of dummy messages. Dummy messages are used to fill
holes in detected threads: referred to by messages found in the
folder, but itself not in the folder.
folder => FOLDER | REF-ARRAY-FOLDERS
Specifies which folders are to be covered by the threads. You
can specify one or more open folders. When you close a folder,
the manager will automatically remove the messages of that folder
from your threads.
folders => FOLDER | REF-ARRAY-FOLDERS
Equivalent to the "folder" option.
log => LEVEL
thread_body => BOOLEAN
May thread-detection be based on the content of a message? This
has a serious performance implication when there are many
messages without "In-Reply-To" and "References" headers in the
folder, because it will cause many messages to be parsed. NOT
IMPLEMENTED YET.
thread_type => CLASS
Type of the thread nodes.
timespan => TIME | 'EVER'
Specify how fast threads usually work: the amount of time between
an answer and a reply. This is used in combination with the
"window" option to determine when to give-up filling the holes in
threads.
See Mail::Box::timespan2seconds() for the possibilities for TIME.
With 'EVER', the search for messages in a thread will only be
limited by the window-size.
trace => LEVEL
window => INTEGER|'ALL'
The thread-window describes how many messages should be checked
at maximum to fill `holes' in threads for folder which use delay-
loading of message headers.
The constant 'ALL' will cause thread-detection not to stop trying
to fill holes, but continue looking until the first message of
the folder is reached. Gives the best quality results, but may
perform bad.
example:
use Mail::Box::Manager;
my $mgr = new Mail::Box::Manager;
my $inbox = $mgr->open(folder => $ENV{MAIL});
my $read = $mgr->open(folder => 'Mail/read');
my $threads = $mgr->threads(folders => [$inbox, $read]);
# longer alternative for last line:
my $threads = $mgr->threads;
$threads->includeFolder($inbox);
$threads->includeFolder($read);
Grouping Folders
$obj->folders
Returns the folders as managed by this threader.
$obj->includeFolder(FOLDERS)
Add one or more folders to the list of folders whose messages are
organized in the threads maintained by this object. Duplicated
inclusions will not cause any problems.
From the folders, the messages which have their header lines parsed
(see Mail::Box about lazy extracting) will be immediately scanned.
Messages of which the header is known only later will have to
report this (see toBeThreaded()).
example:
$threads->includeFolder($inbox, $draft);
$obj->removeFolder(FOLDERS)
Remove one or more folders from the list of folders whose messages
are organized in the threads maintained by this object.
example:
$threads->removeFolder($draft);
The Threads
$obj->all
Returns all messages which start a thread. The list may contain
dummy messages and messages which are scheduled for deletion.
To be able to return all threads, thread construction on each
message is performed first, which may be slow for some folder-types
because is will enforce parsing of message-bodies.
$obj->known
Returns the list of all messages which are known to be the start of
a thread. Threads containing messages which where not read from
their folder (like often happens MH-folder messages) are not yet
known, and hence will not be returned.
The list may contain dummy messages, and messages which are
scheduled for deletion. Threads are detected based on explicitly
calling inThread() and thread() with a messages from the folder.
Be warned that, each time a message's header is read from the
folder, the return of the method can change.
$obj->sortedAll([PREPARE [COMPARE]])
Returns all() the threads by default, but sorted on timestamp.
$obj->sortedKnown([PREPARE [,COMPARE]])
Returns all known() threads, in sorted order. By default, the
threads will be sorted on timestamp, But a different COMPARE method
can be specified.
$obj->thread(MESSAGE)
Returns the thread where this MESSAGE is the start of. However,
there is a possibility that this message is a reply itself.
Usually, all messages which are in reply of this message are dated
later than the specified one. All headers of messages later than
this one are getting parsed first, for each folder in this threads-
object.
example:
my $threads = $mgr->threads(folder => $inbox);
my $thread = $threads->thread($inbox->message(3));
print $thread->string;
$obj->threadStart(MESSAGE)
Based on a message, and facts from previously detected threads, try
to build solid knowledge about the thread where this message is in.
Internals
$obj->createDummy(MESSAGE-ID)
Get a replacement message to be used in threads. Be warned that a
dummy is not a member of any folder, so the program working with
threads must test with Mail::Message::isDummy() before trying
things only available to real messages.
$obj->inThread(MESSAGE)
Collect the thread-information of one message. The `In-Reply-To'
and `Reference' header-fields are processed. If this method is
called on a message whose header was not read yet (as usual for MH-
folders, for instance) the reading of that header will be triggered
here.
$obj->outThread(MESSAGE)
Remove the message from the thread-infrastructure. A message is
replaced by a dummy.
$obj->toBeThreaded(FOLDER, MESSAGES)
Include the specified messages in/from the threads managed by this
object, if this folder is maintained by this thread-manager.
$obj->toBeUnthreaded(FOLDER, MESSAGES)
Remove the specified messages in/from the threads managed by this
object, if this folder is maintained by this thread-manager.
Error handling
$obj->AUTOLOAD
See "Error handling" in Mail::Reporter
$obj->addReport(OBJECT)
See "Error handling" in Mail::Reporter
$obj->defaultTrace([LEVEL]|[LOGLEVEL, TRACELEVEL]|[LEVEL, CALLBACK])
Mail::Box::Thread::Manager->defaultTrace([LEVEL]|[LOGLEVEL,
TRACELEVEL]|[LEVEL, CALLBACK])
See "Error handling" in Mail::Reporter
$obj->errors
See "Error handling" in Mail::Reporter
$obj->log([LEVEL [,STRINGS]])
Mail::Box::Thread::Manager->log([LEVEL [,STRINGS]])
See "Error handling" in Mail::Reporter
$obj->logPriority(LEVEL)
Mail::Box::Thread::Manager->logPriority(LEVEL)
See "Error handling" in Mail::Reporter
$obj->logSettings
See "Error handling" in Mail::Reporter
$obj->notImplemented
See "Error handling" in Mail::Reporter
$obj->report([LEVEL])
See "Error handling" in Mail::Reporter
$obj->reportAll([LEVEL])
See "Error handling" in Mail::Reporter
$obj->trace([LEVEL])
See "Error handling" in Mail::Reporter
$obj->warnings
See "Error handling" in Mail::Reporter
Cleanup
$obj->DESTROY
See "Cleanup" in Mail::Reporter
$obj->inGlobalDestruction
See "Cleanup" in Mail::Reporter
DETAILS
Maintaining threads
A "Mail::Box::Thread::Manager" object is created by the
Mail::Box::Manager, using Mail::Box::Manager::threads(). Each object
can monitor the thread-relations between messages in one or more
folders. When more than one folder is specified, the messages are
merged while reading the threads, although nothing changes in the
folder-structure. Adding and removing folders which have to be
maintained is permitted at any moment, although may be quite costly in
performance.
An example of the maintained structure is shown below. The
Mail::Box::Manager has two open folders, and a thread-builder which
monitors them both. The combined folders have two threads, the second
is two long (msg3 is a reply on msg2). Msg2 is in two folders at once.
manager
| \
| `----------- threads
| | |
| thread thread---thread
| | /| /
| | // /
+---- folder1 | // /
| | / // /
| `-----msg1 // /
| `-----msg2-'/ /
| / /
`-----folder2 / /
| / /
`-----msg2 /
`-----msg3------'
Delayed thread detection
With all() you get the start-messages of each thread of this folder.
When that message was not found in the folder (not saved or already
removed), you get a message of the dummy-type. These thread
descriptions are in perfect state: all messages of the folder are
included somewhere, and each missing message of the threads (holes) are
filled by dummies.
However, to be able to detect all threads it is required to have the
headers of all messages, which is very slow for some types of folders,
especially MH and IMAP folders.
For interactive mail-readers, it is preferred to detect threads only on
messages which are in the viewport of the user. This may be sloppy in
some situations, but everything is preferable over reading an MH
mailbox with 10k e-mails to read only the see most recent messages.
In this object, we take special care not to cause unnecessary parsing
(loading) of messages. Threads will only be detected on command, and
by default only the message headers are used.
The following reports the Mail::Box::Thread::Node which is related to a
message:
my $thread = $message->thread;
When the message was not put in a thread yet, it is done now. But,
more work is done to return the best thread. Based on various
parameters, which where specified when the folder was created, the
method walks through the folder to fill the holes which are in this
thread.
Walking from back to front (recently arrived messages are usually in
the back of the folder), message after message are triggered to be
included in their thread. At a certain moment, the whole thread of the
requested method is found, a certain maximum number of messages was
tried, but that didn't help (search window bound reached), or the
messages within the folder are getting too old. Then the search to
complete the thread will end, although more messages of them might have
been in the folder: we don't scan the whole folder for performance
reasons.
Finally, for each message where the head is known, for instance for all
messages in mbox-folders, the correct thread is determined immediately.
Also, all messages where the head get loaded later, are automatically
included.
This module implements thread-detection on a folder. Messages created
by the better mailers will include "In-Reply-To" and "References"
lines, which are used to figure out how messages are related. If you
prefer a better thread detection, they are implementable, but there may
be a serious performance hit (depends on the type of folder used).
DIAGNOSTICS
Error: Package $package does not implement $method.
Fatal error: the specific package (or one of its superclasses) does
not implement this method where it should. This message means that
some other related classes do implement this method however the
class at hand does not. Probably you should investigate this and
probably inform the author of the package.
SEE ALSO
This module is part of Mail-Box distribution version 2.097, built on
January 26, 2011. Website: http://perl.overmeer.net/mailbox/
LICENSE
Copyrights 2001-2011 by Mark Overmeer. For other contributors see
ChangeLog.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself. See
http://www.perl.com/perl/misc/Artistic.html
perl v5.14.1 2011-01-26 Mail::Box::Thread::Manager(3)
