Tinymail workshop
Sergio Villar Senín
English translation by Arien

What is tinymail?
-----------------

 * Started in January 2006 by Philip Van Hoof
 
 * Pronounced as “tinny-mail”
 
 * Framework for development of email applications
 
 * Oriented towards portable devices
    - Nokia N770, N800
    - One Laptop Per Child
    - GPE
 
 * Tinymail is LGPL


Tinymail is a framework
-----------------------

 * tinymail ISN’T an email client

 * Offers the basic components of an email client (MUA)
    - A client in 90 lines of Python!

 * Uses Camel as default implementation

 * tinymail supports:
    - IMAP with Lemonade. Push e-mail.
    - POP3
    - SMTP, sendmail
    - Local storage
    - Offline mode


Why is tinymail needed?
-----------------------

 * Evolution, Thunderbird are OK, but...
    - Consume a lot of resources
    - Desktop interfaces

 * Portable devices
    - Few resources
    - Very different architectures
    - Very different interfaces

 * We need something more generic


Memory use in tinymail
----------------------

 * How much memory can an email program consume?
    - Summary information
    - 4 bytes x 20 fields x 20.000 emails ≈ 1.5MB (in pointers!!!)

    [graph]

    Memory use by Evolution when loading a folder with 30000 emails


Memory use in tinymail (2)
--------------------------

 * mmap()
    - Memory-mapping a file on POSIX systems
    - Efficient memory use
       * No copies to user space
       * Shared memory between multiple processes
    - Faster access
       * Accessing contents through simple pointers.  No syscalls
       * Grouping multiple modifications in a single I/O operation
    - Demand paging. If it’s not needed, it’s not loaded
    - Not a panacea: more page faults


Memory use in tinymail (3)
--------------------------

 * Okay, so how much memory does tinymail use?
    - Administrative data structures ≈ several hundreds of KB
    - Downloading summaries for the first time forces having all the
      data in memory:
       * Optimization: every 1000 items the data are dumped to disk and
         a new mmap-ed file is loaded

 * And graphically?


Memory use in tinymail (4)
--------------------------

                                [graph]

 * Memory use when loading the contents of folders with: 700, 50000,
   5000, 500, 40000, 30000, 3000, 2000, 200, 10000, 1000, and 100 emails
   for the first time.

 * Source: http://tinymail.org/trac/tinymail/wiki/MemoryStats


What is tinymail like?
----------------------

 * Two-layer architecture
    - service layer
    - user interface layer

 * Design
    - Based on GObject and GTypeInterface
    - Design patterns: strategies, proxies...
    - Extensive use of interfaces
    - Possible to re-implement almost everything
    - Possible to inherit from almost everything
    - Efficient use of Streams


Tinymail architecture
---------------------

 * Service layer
    - libtinymail: interfaces of the service layer
    - libtinymail-camel: implementation using Camel

 * User interface layer
    - libtinymailui: interfaces of the user interface layer
    - libtinymailui-gtk: implementation using Gtk+

 * Platform dependent components
    - libtinymail-gnome-desktop: GNOME
    - libtinymail-maemo: Maemo
    - libtinymail-olpc: OLPC
    - libtinymail-gpe: GPE


Some design
-----------

 * Design of email accounts

   [image]


Some design (2)
---------------

 * Design of folders and messages

   [image]


Some code
---------

 * How to create a plain text message

   [example]


More information
----------------

 * tinymail
    - Web: http://tinymail.org/
    - Trac: http://tinymail.org/trac/tinymail/
    - Mailing lists: mailto:tinymail-devel-list@gnome.org
    - IRC: #tinymail on GimpNET

 * Projects using tinymail
    - Modest: http://modest.garage.maemo.org/


By the way...
-------------

 * Any questions?

  
Pitching in
-----------

 * tinymail core tasks
    - http://tinymail.org/trac/tinymail/wiki/DesignAndCoding

 * Gtk+ tasks
    - Adding drag-and-drop to the demo
    - Support for the GtkUIManager

 * Qt tasks
    - Support for GMainloop in KDE 4?
    - Adding compilation dependencies
    - libtinymail-kde-desktop