NAME

Mail::Mbox::MessageParser::Cache - A cache-based mbox folder reader

SYNOPSIS

#!/usr/bin/perl

use Mail::Mbox::MessageParser::Cache;

# Set up cache
Mail::Mbox::MessageParser::Cache::SETUP_CACHE(
  { 'file_name' => '/tmp/cache' } );

my $filename = 'mail/saved-mail';
my $filehandle = new FileHandle($filename);

my $folder_reader =
  new Mail::Mbox::MessageParser::Cache( {
    'file_name' => $filename,
    'file_handle' => $filehandle,
  } );

die $folder_reader unless ref $folder_reader;

die "No cached information"
  if $Mail::Mbox::MessageParser::Cache::UPDATING_CACHE;

# Any newlines or such before the start of the first email
my $prologue = $folder_reader->prologue;
print $prologue;

# This is the main loop. It's executed once for each email
while(!$folder_reader->end_of_file());
{
  my $email = $folder_reader->read_next_email();
  print $email;
}

DESCRIPTION

This module implements a cached-based mbox folder reader. It can only be used when cache information already exists. Users are encouraged to use Mail::Mbox::MessageParser instead. The base MessageParser module will automatically fall back to another reader implementation if cached information is not available, and will fill the cache after parsing is done.

METHODS AND FUNCTIONS

The following methods and functions are specific to the Mail::Mbox::MessageParser::Cache package. For additional inherited ones, see the Mail::Mbox::MessageParser documentation.

SETUP_CACHE(...)

SETUP_CACHE( { 'file_name' => <cache file name> } );

<cache file name> - the file name of the cache

Call this function once to set up the cache before creating any parsers. You must provide the location to the cache file. There is no default value.

Returns an error string or 1 if there is no error.

CLEAR_CACHE();

Use this function to clear the cache and delete the cache file. Normally you should not need to clear the cache--the module will automatically update the cache when the mailbox changes. Call this function after SETUP_CACHE.

WRITE_CACHE();

Use this function to force the module to write the in-memory cache information to the cache file. Normally you do not need to do this--the module will automatically write the information when the program exits.

$ref = new( { 'file_name' => <mailbox file name>, 'file_handle' => <mailbox file handle> });

<file_name> - The full filename of the mailbox
<file_handle> - An opened file handle for the mailbox

The constructor for the class takes two parameters. file_name is the filename of the mailbox. This will be used as the cache key, so it's important that it fully defines the path to the mailbox. The file_handle argument is the opened file handle to the mailbox. Both arguments are required.

Returns a reference to a Mail::Mbox::MessageParser object, or a string describing the error.

BUGS

No known bugs.

Contact david@coppit.org for bug reports and suggestions.

AUTHOR

David Coppit <david@coppit.org>.

LICENSE

This software is distributed under the terms of the GPL. See the file "LICENSE" for more information.

HISTORY

This code was originally part of the grepmail distribution. See http://grepmail.sf.net/ for previous versions of grepmail which included early versions of this code.

SEE ALSO

Mail::Mbox::MessageParser