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MaildirA ruby library for reading and writing messages in the maildir format.
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What’s so great about the maildir formatSee cr.yp.to/proto/maildir.html and en.wikipedia.org/wiki/Maildir
“Two words: no locks.” – Daniel J. Berstein
The maildir format allows multiple processes to read and write arbitrary messages without file locks.
New messages are initially written to a “tmp” directory with an automatically-generated unique filename. After the message is written, it’s moved to the “new” directory where other processes may read it.
While the maildir format was created for email, it works well for arbitrary data. This library can read & write email messages or arbitrary data. See Pluggable serializers for more.
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Installsudo gem install maildir
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UsageCreate a maildir in /home/aaron/mail
maildir = Maildir.new("/home/aaron/mail") # creates tmp, new, and cur dirs # call Maildir.new("/home/aaron/mail", false) to skip directory creation.
Add a new message. This creates a new file with the contents “Hello World!”; returns the path fragment to the file. Messages are written to the tmp dir then moved to new.
message = maildir.add("Hello World!")
List new messages
maildir.list(:new) # => [message]
Move the message from “new” to “cur” to indicate that some process has retrieved the message.
message.process
Indeed, the message is in cur, not new.
maildir.list(:new) # => [] maildir.list(:cur) # => [message]
Add some flags to the message to indicate state. See “What can I put in info” at cr.yp.to/proto/maildir.html for flag conventions.
message.add_flag("S") # Mark the message as "seen" message.add_flag("F") # Mark the message as "flagged" message.remove_flag("F") # unflag the message message.add_flag("T") # Mark the message as "trashed"
Get a key to uniquely identify the message
key = message.key
Load the contents of the message
data = message.data
Find the message based using the key
message_copy = maildir.get(key) message == message_copy # => true
Delete the message from disk
message.destroy # => returns the frozen message maildir.list(:cur) # => []
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Pluggable serializersBy default, message data are written and read from disk as a string. It’s often desirable to process the string into a useful object. Maildir supports configurable serializers to convert message data into a useful object.
The following serializers are included:
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Maildir::Serializer::Base (the default)
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Maildir::Serializer::Mail
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Maildir::Serializer::Marshal
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Maildir::Serializer::JSON
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Maildir::Serializer::YAML
Maildir::Serializer::Base simply reads and writes strings to disk.
Maildir::Message.serializer # => Maildir::Serializer::Base.new (by default) message = maildir.add("Hello World!") # writes "Hello World!" to disk message.data # => "Hello World!"
The Mail serializer takes a ruby Mail object (github.com/mikel/mail) and writes RFC2822 email messages.
require 'maildir/serializer/mail' Maildir::Message.serializer = Maildir::Serializer::Mail.new mail = Mail.new(...) message = maildir.add(mail) # writes an RFC2822 message to disk message.data == mail # => true; data is parsed as a Mail object
The Marshal, JSON, and YAML serializers work similarly. E.g.:
require 'maildir/serializer/json' Maildir::Message.serializer = Maildir::Serializer::JSON.new my_data = {"foo" => nil, "my_array" => [1,2,3]} message = maildir.add(my_data) # writes {"foo":null,"my_array":[1,2,3]} message.data == my_data # => true
It’s trivial to create a custom serializer. Implement the following two methods:
load(path) dump(data, path)
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ContributorsNiklas E. Cathor (github.com/nilclass) added subdir & courierimapkeywords support
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CopyrightCopyright © 2010 Aaron Suggs. See LICENSE for details.