NAME

       Mail::Box::MH::Index - keep index files for messages.

INHERITANCE

        Mail::Box::MH::Index
          is a Mail::Reporter

SYNOPSIS

        my $index = Mail::Box::MH::Index->new;
        $index->read(...)
        $index->write(...)

DESCRIPTION

       Message folders which store their data in one single file per message are very inefficient
       for producing subject overviews and for computing message threads.  The
       "Mail::Box::MH::Index" object is able to store and read a the headers of a set of
       "Mail::Box::MH::Message" messages which are part of a single "Mail::Box::MH" folder in one
       file.

       When the "Mail::Box::MH::Index" functionality is enabled by specifying
       Mail::Box::MH::new(keep_index) when opening a folder, the index file is automatically
       read.  When the folder is closed, a new index file is created.

       Special care is taken to avoid problems which occur when the user changes or removes
       message files without updating the index. If the index is not trustworthy it will not be
       used (costing some performance for the reader of the folder).

       See documentation in the base class.

METHODS

       See documentation in the base class.

   Constructors
       See documentation in the base class.

       Mail::Box::MH::Index->new(OPTIONS)
            -Option   --Defined in     --Default
             filename                    <required>
             head_type                   Mail::Message::Head::Subset
             head_wrap                   72
             log        Mail::Reporter   'WARNINGS'
             trace      Mail::Reporter   'WARNINGS'

           filename => FILENAME
             The FILENAME which is used to store the headers of all the e-mails for one folder.
             This must be an absolute pathname.

           head_type => CLASS
             The type of headers which will be used to store header information when it is read
             from the index file.  You can not be sure the index contains all header line (the
             mailbox may have been updated without updating the index) so this will usually be
             (an sub-class of) Mail::Message::Head::Subset.

           head_wrap => INTEGER
             The preferred number of character in each header line.

           log => LEVEL
           trace => LEVEL

   The Index
       $obj->append(MESSAGES)
           Append MESSAGES to the index file.

       $obj->filename()
           Returns the name of the index file.

       $obj->get(MSGFILE)
           Look if there is header info for the specified MSGFILE.  The filename represents one
           message in folder type which are organized as directory.  This method will return an
           object of the new(head_type) as specified during creation of the index object, or
           "undef" if the information is not known or not trustworthy -i.e. the file size
           changed.

       $obj->read()
           Read the index file.  The header objects can after this be requested with the get()
           method.

       $obj->write(MESSAGES)
           Write an index file containing the headers specified MESSAGES (Mail::Message objects).

   Error handling
       See documentation in the base class.

       $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::MH::Index->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::MH::Index->log([LEVEL [,STRINGS]])
           See "Error handling" in Mail::Reporter

       $obj->logPriority(LEVEL)
       Mail::Box::MH::Index->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
       See documentation in the base class.

       $obj->DESTROY()
           See "Cleanup" in Mail::Reporter

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 2.110, built on January 05, 2014.
       Website: http://perl.overmeer.net/mailbox/

LICENSE

       Copyrights 2001-2014 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