Message dir¶ ↑

A directory, with messages. Like your Maildir/

Meant to be used to safely store incoming messages from any slow connection

# create
dir = MessageDir.new("/path/to/store")
msg = dir.new do |fh|
  fh.puts info_from_slow_connection
end

# move a message to cur/
dir.cur(msg)
msg.cur!

# get a list of all messages
dir.messages

# get a list of all messages in new/
dir.messages(:new)

# or cur
dir.messages(:cur)

# work on a message (moves it to tmp/ for the duration of a block)
dir.process(msg, File::WRONLY|File::APPEND) do |fh|
  fh.puts more_info
end

msg.process(File::WRONLY|File::TRUNC) do |fh|
  fh.puts new_contents
end

# remove a message
msg = dir.messages(:new).first
dir.rm(msg) # => raise exception, we dont like to remove 'new' messages

msg = dir.msgs(:cur).first
msg.rm!

# lock a message
msg.lock! do
  # something with the locked message
end
msg.locked? # => false

dir.lock(msg) do
end

A message is not an implementation of IO or File but it acts in the same way. Use that to your advantage.

A lot is done to ensure the safe handling of messages

• Messages are created and processed in tmp/

• A message fh is always opened with File::SYNC - slow but trustworthy

• Locks are carried over processes (and crashes) using .lock files