One week before the wedding, to Laura: Mono won t just clear up right away. One week before the wedding, to me: That s going to need stitches. Yes, not long before the wedding, Laura had come down with mononucleosis and I had cut into my finger with a very sharp knife while cutting bread requiring a trip to the emergency room to get stitches. Two days before we got married, instead of moving furniture, I was getting stitches out of my finger. It wasn t the kind of week we had planned. But it was the happiest, most amazing occasion I could have ever imagined. As I wrote last month, I am richly blessed indeed. Our wedding was three days after Christmas. The church was still decorated for Christmas, with the tree in on corner, glittering stars suspended in mid-air on cables from the walls, wreaths and candles in the windows, and it was a joy-filled day. Before the ceremony, we took pictures the only part of the day Jacob and Oliver weren t thrilled with. Nevertheless, we got some fun ones. Laura and I seem to know quite a few pastors between us and not just because Laura is a pastor. My brother officiated with the wedding vows, his wife with scripture and a prayer of blessing, and the church s pastor gave the message. Laura and I wrote in our wedding program, Music has long been a thread running through both our lives. We have enjoyed singing together, playing piano and pennywhistle duets, attending concerts, and even exploring old hymnals. Music is also one of the best ways to have a conversation even a conversation with God. We wrote a page in the program about each of the hymns that were a part of the wedding, and why we picked them. The combined church choirs of my home church and Laura s church sang John Rutter s beautiful arrangement of For the Beauty of the Earth (click here to listen to a different choir). Hearing For the beauty of each hour , For the joy of human love , and Lord of all, to thee we raise this our joyful hymn of praise was perfect for the day. It was with such great happiness that we walked out of the sanctuary, a married couple, to the sound of the congregation singing Joy to the World! Jacob and Oliver were so very excited on our wedding day. They happily explored the church while waiting for things to happen. We had them help us light our unity candle, and they were pleased with that. Jacob loved his suit, which made him look just like me. And they were, of course, delighted with the cake and in the middle of it all. For our honeymoon, we managed to get two weeks of vacation, and spent about half of it at home. We had looked at various options for retreats in the country, but eventually concluded that our house is a retreat in the country, so might as well enjoy it at home. We also went to the Palo Duro Canyon area near Amarillo in the Texas panhandle, staying in a small B&B in Canyon, TX. Palo Duro is the second-largest canyon in North America, and quite colorful year-round. What a beautiful place to go for our honeymoon! By the time we got there, Laura was getting past mono, and we went for hikes in the canyon on two different days hiking a total of 10 miles, including a hike up the side of the canyon. After we got back home, on the last weekday of our honeymoon, we went back to the Flint Hills of Kansas, to some of the same places we had spent our third date. We climbed the windy staircase at the Chase County Courthouse, the oldest courthouse still in use in Kansas. And peered out its famous oval window. We found the last remnant of the old ghost town of Elk, ate at the same restaurant we had that day. It brought back wonderful memories, and it was a good day in itself. Because even though it was a gold, drizzly, overcast day in January, this time, we were married. And this year, Thanksgiving is all year.

Quest for a terminal emulator The requirements I need a terminal emulator. This is a checklist of the features that I need:

• Foreground colour: #aaaaaa.
• Background colour: black.
• "Linux console" colour palette.
• Font: Monospace-10.
• Alt+Fnn to directly switch to one of the first 12 terminals, like in the Linux console.
• F11 to toggle fullscreen.
• Alt+'+', Alt+'-', Alt+'0' to control font sizes.
• All other keybindings disabled, so that terminal programs are free to use them.
• I occasionally need to switch to black-on-white for presentations.
• Tabs.
• When I open a new tab it needs to contain a shell opened inside the same directory of the last tab I was in. The way I normally start working is something like: cd workdir; x-terminal-emulator -e vim todolist and then I start opening new tabs.
• I need -e to work. In fact, I need the terminal to work as x-terminal-emulator -e cmd args...
• I need to conveniently pick a URL in a terminal and open it in Chromium, and not any other browser. Even better, open it in x-www-browser

My experience is that getting all of this to work is not being as easy as it seems, so I'm creating this page to track progress. gnome-terminal I've been happily using this for years, and it did everything I needed, until some months ago it started to open new tabs in the terminal's working directory instead of the last tab's working directory. This is a big point of frustration for me. It also started opening https urls with Firefox, although the preferred browser was Chromium. There seemed to be no way to control it: I looked for firefox or iceweasel in all gconf and dconf settings and found nothing. The browser issue was fixed by accident when I used Xfce4's settings application to change the browser from Chromium to Firefox and then back to Chromium. update, thanks to Mathieu Parent, Josh Triplett, Peter De Wachter, Julien Cristau, and Charles Plessy: It is also possible to restore the "new tab opened inside the same directory of the last tab I was in" behaviour, by enabling "run command as a login shell" so that /etc/profile.d/vte.sh is run (thanks Mathieu Parent for the link). That in turn spawned extra cleanup work in my .bashrc/.bash_profile/.profile setup, which has been randomly evolving since even before my first Debian "buzz" system. I found that it was setting PROMPT_COMMAND to something else to set the terminal title, conflicting with what vte.sh wants to do. With regards to loading /etc/profile.d/vte.sh by default, Peter De Watcher sent pointers to relevant bugs: here, here, and here. An alternative strategy is to work using the prompt rather than PROMPT_COMMAND; an example is in Josh Triplett's .bashrc from git://joshtriplett.org/git/home. Josh Triplett also said:

To fix the browser launched for URLs, you either need to use a desktop environment following GNOME's mechanism for setting the default browser, or edit ~/.local/share/applications/mimeapps.list and make sure x-scheme-handler/http, x-scheme-handler/https, and x-scheme-handler/ftp are set to your preferred browser's desktop file basename under [Added Associations].

All my issues with gnome-terminal are now gone and I'm only too happy to go back to it. rxvt-unicode-256color urxvt took some work. This is where I got with configuration:

URxvt.font: xft:Monospace-10:antialias=true
URxvt.foreground: #aaaaaa
URxvt.background: black
URxvt.scrollBar_right: true
URxvt.cursorBlink: true
URxvt.perl-ext-common: default,matcher,tabbedex
URxvt.url-launcher: /usr/bin/x-www-browser
URxvt.matcher.button: 1
URxvt.perl-lib: /home/enrico/.urxvt/perl
URxvt.color0: black
URxvt.color1: #aa0000
URxvt.color2: #00aa00umask
URxvt.color3: #aa5500
URxvt.color4: #0000aa
URxvt.color5: #aa00aa
URxvt.color6: #00aaaa
URxvt.color7: #aaaaaa
URxvt.color8: #555555
URxvt.color9: #ff5555
URxvt.color10: #55ff55
URxvt.color11: #ffff55
URxvt.color12: #5555ff
URxvt.color13: #ff55ff
URxvt.color14: #55ffff
URxvt.color15: #ffffff

I got all of the tab behaviour that I need by "customizing" the tab script (yuck github ). Missing

• Bold fonts only work if I set TERM=rxvt
• The implementation for opening a new tab in the directory of the current tab is rather fragile.
• Resizing the terminal window causes an annoying flicker

sakura Configuration is in .config/sakura/sakura.conf and these bits help:

colorset1_fore=rgb(170,170,170)
colorset1_back=rgb(0,0,0)
colorset1_opacity=99
colorset2_fore=rgb(0,0,0)
colorset2_back=rgb(254,254,254)
colorset2_opacity=99
font=Monospace 10
show_always_first_tab=No
scrollbar=false
fullscreen_key=F11
palette=linux

Missing

• Alt+Fnn to directly switch to one of the first 12 terminals, like in the Linux console. Sakura hardcodes using numbers for switching, and only allows to change the modifier.
• Alt+'+', Alt+'-', Alt+'0' to control font sizes.
• Tabs are huge and take way too much screen space.

lxterminal Configuration is in .config/lxterminal/lxterminal.conf and this is relevant to me:

[general]
fontname=DejaVu Sans Mono 10
fgcolor=#aaaaaaaaaaaa
disallowbold=false
cursorblinks=true
tabpos=top
hidescrollbar=false
hidemenubar=true
hideclosebutton=true
disablef10=true
disablealt=true

Also, to open a url directly you control+click it. Missing

• Alt+Fnn to directly switch to one of the first 12 terminals, like in the Linux console.
• F11 to toggle fullscreen.
• Alt+'+', Alt+'-', Alt+'0' to control font sizes.
• I occasionally need to switch to black-on-white for presentations: this is inconvenient, as it requires to set foreground and background separately each time.

terminator Configuration is in .config/terminator/config and this is relevant to me:

[global_config]
  use_custom_url_handler = True
  custom_url_handler = x-www-browser
  inactive_color_offset = 1.0
[keybindings]
  close_term = None
  close_window = None
  copy = None
  cycle_next = None
  cycle_prev = None
  go_down = None
  go_next = None
  go_prev = None
  go_up = None
  group_all = None
  group_tab = None
  hide_window = None
  move_tab_left = None
  move_tab_right = None
  new_tab = None
  new_terminator = None
  new_window = None
  next_tab = None
  paste = None
  prev_tab = None
  reset_clear = None
  reset = None
  resize_down = None
  resize_left = None
  resize_right = None
  resize_up = None
  rotate_ccw = None
  rotate_cw = None
  scaled_zoom = None
  search = None
  split_horiz = None
  split_vert = None
  switch_to_tab_1 = <Alt>F1
  switch_to_tab_2 = <Alt>F2
  switch_to_tab_3 = <Alt>F3
  switch_to_tab_4 = <Alt>F4
  switch_to_tab_5 = <Alt>F5
  switch_to_tab_6 = <Alt>F6
  switch_to_tab_7 = <Alt>F7
  switch_to_tab_8 = <Alt>F8
  switch_to_tab_9 = <Alt>F9
  switch_to_tab_10 = <Alt>F10
  toggle_scrollbar = None
  toggle_zoom = None
  ungroup_all = None
  ungroup_tab = None
[profiles]
  <span class="createlink">default</span>
    palette = "#000000:#aa0000:#00aa00:#aa5500:#0000aa:#aa00aa:#00aaaa:#aaaaaa:#555555:#ff5555:#55ff55:#ffff55:#5555ff:#ff55ff:#55ffff:#ffffff"
    copy_on_selection = True
    icon_bell = False
    background_image = None
    show_titlebar = False

Missing

• I need -e to work. In fact, I need the terminal to work as x-terminal-emulator -e cmd args.... #734655 but should be fixed soon
• New windows start with the title bar visible, even if I configured it not to show. It disappears as soon as the window gets focused, causing the terminal contents to resize. It is just a glitch, but oh so annoying!

update: Richard Hartmann pointed out that terminator's upstream maintainer now changed after the old one didn't have time any more, and it should have a release with a ton of improvements anytime soon. xfce4-terminal Configuration is in .config/xfce4/terminal, and this is relevant to me: terminalrc:

[Configuration]
FontName=Monospace 10
MiscAlwaysShowTabs=FALSE
MiscBell=FALSE
MiscBordersDefault=TRUE
MiscCursorBlinks=FALSE
MiscCursorShape=TERMINAL_CURSOR_SHAPE_BLOCK
MiscDefaultGeometry=80x24
MiscInheritGeometry=FALSE
MiscMenubarDefault=FALSE
MiscMouseAutohide=FALSE
MiscToolbarDefault=FALSE
MiscConfirmClose=TRUE
MiscCycleTabs=TRUE
MiscTabCloseButtons=TRUE
MiscTabCloseMiddleClick=TRUE
MiscTabPosition=GTK_POS_TOP
MiscHighlightUrls=TRUE
ShortcutsNoMenukey=TRUE
ShortcutsNoMnemonics=TRUE
ColorForeground=#aaaaaaaaaaaa

accels.scm:

(gtk_accel_path "<Actions>/terminal-window/goto-tab-1" "<Alt>F1")
(gtk_accel_path "<Actions>/terminal-window/goto-tab-2" "<Alt>F2")
(gtk_accel_path "<Actions>/terminal-window/goto-tab-3" "<Alt>F3")
(gtk_accel_path "<Actions>/terminal-window/goto-tab-4" "<Alt>F4")
(gtk_accel_path "<Actions>/terminal-window/goto-tab-5" "<Alt>F5")
(gtk_accel_path "<Actions>/terminal-window/goto-tab-6" "<Alt>F6")
(gtk_accel_path "<Actions>/terminal-window/goto-tab-7" "<Alt>F7")
(gtk_accel_path "<Actions>/terminal-window/goto-tab-8" "<Alt>F8")
(gtk_accel_path "<Actions>/terminal-window/goto-tab-9" "<Alt>F9")
(gtk_accel_path "<Actions>/terminal-window/goto-tab-10" "<Alt>F10")
(gtk_accel_path "<Actions>/terminal-window/goto-tab-11" "<Alt>F11")
(gtk_accel_path "<Actions>/terminal-window/goto-tab-12" "<Alt>F12")

update: Yves-Alexis Perez points out that to disable the F1 for help in the terminal, you need to remove the accelerator. I tried this and this and didn't have success, but I confess I did not dig too much into it. Although xfce4-terminal -e does not work as I expect, xfce4-terminal registers a wrapper for x-terminal-emulator that does the right thing with respect to -e (also thanks Yves-Alexis Perez). Missing

• Alt+'+', Alt+'-', Alt+'0' to control font sizes.
• All other keybindings disabled, so that terminal programs are free to use them. I could not find a way to disable F1 for help.
• I occasionally need to switch to black-on-white for presentations. I can switch to a "Black on white" preset, but there is no "Gray on black" to switch back to. I can switch back to "White on black", but then I need to manually set the text colour to #aaaaaa. update: Yves-Alexis Perez found that you can add presets to .local/share/colorthemes taking examples from /usr/share/xfce4/terminal/colorschemes; next time I consider switching to xfce4-terminal I'll try that.

roxterm Configuration is in .config/roxterm.sourceforge.net/ split in several files corresponding to profiles. This is a reasonable starting point for me: Profiles/Default:

[roxterm profile]
colour_scheme=Default
disable_menu_access=1
disable_menu_shortcuts=1
disable_tab_menu_shortcuts=0
tab_close_btn=0
hide_menubar=1
always_show_tabs=0

Colours/Default:

[roxterm colour scheme]
0=#000000000000
1=#aaaa00000000
2=#0000aaaa0000
3=#aaaa55550000
4=#00000000aaaa
5=#aaaa0000aaaa
6=#0000aaaaaaaa
7=#aaaaaaaaaaaa
8=#555555555555
9=#ffff55555555
10=#5555ffff5555
11=#ffffffff5555
12=#55555555ffff
13=#ffff5555ffff
14=#5555ffffffff
15=#ffffffffffff
palette_size=16
foreground=#aaaaaaaaaaaa
background=#000000000000
cursor=#cccccccccccc
bold=
dim=

Shortcuts/Default:

[roxterm shortcuts scheme]
File/New Window=
File/New Tab=
File/Close Window=
File/Close Tab=
Tabs/Previous Tab=
Tabs/Next Tab=
Edit/Copy=
Edit/Paste=
View/Zoom In=<Control>plus
View/Zoom Out=<Control>minus
View/Normal Size=<Control>0
View/Full Screen=F11
View/Scroll Up One Line=
View/Scroll Down One Line=
Help/Help=
Edit/Copy & Paste=
Search/Find...=
Search/Find Next=
Search/Find Previous=
File/New Window With Profile/Default=
File/New Tab With Profile/Default=
Tabs/Select_Tab_0=<Alt>F1
Tabs/Select_Tab_1=<Alt>F2
Tabs/Select_Tab_2=<Alt>F3
Tabs/Select_Tab_3=<Alt>F4
Tabs/Select_Tab_4=<Alt>F5
Tabs/Select_Tab_5=<Alt>F6
Tabs/Select_Tab_6=<Alt>F7
Tabs/Select_Tab_7=<Alt>F8
Tabs/Select_Tab_8=<Alt>F9
Tabs/Select_Tab_9=<Alt>F9
Tabs/Select_Tab_10=<Alt>F10
Tabs/Select_Tab_11=<Alt>F11
Tabs/Select_Tab_12=<Alt>F12

Global:

[roxterm options]
edit_shortcuts=0
prefer_dark_theme=1
colour_scheme=Default
warn_close=1

Missing Nothing of my initial requirements seems to be missing, really, so I'm sticking to it for a while to see what happens. The first itch to scratch is that when the menubar is hidden, the popup menu becomes the entire menubar contents, which does not fit the general use case to have a contextual menu with the most common shortcuts. I'll just declare it useless and get myself used to some new hotkey for starting a new terminal. update: after fixing my issues with gnome-terminal I've switched back to gnome-terminal: its interface feels less clunky as I'm already used to it. Other references Guillem Jover made a similar analysis in 2009, it can be found here. Thomas Koch mentioned that termit should be able to do all I need, and is scriptable in Lua. I like the sound of that, and it's definitely one I should look next time I find myself shopping for terminal emulators.

Contributor License Agreements ("CLAs") are a mechanism for an upstream software developer to insist that contributors grant the upstream developer some additional set of rights. These range in extent - some CLAs require that the contributor reassign their copyright over the contribution to the upstream developer, some merely provide the upstream developer with a grant of rights that aren't explicit in the software license (such as an explicit patent grant for a contribution licensed under a BSD-style license).

CLAs aren't new. FSF-copyrighted projects have been using copyright assignment since at least 1985 - in return, the FSF promise that the software will always be distributed under a copyleft-style license. For over a decade, Apache Software Foundation projects have required that contributors sign a CLA that allows them to retain copyright, but grants the ASF the right to relicense the work as it wishes. For the most part, this hasn't been terribly controversial.

So why do people object so much when Canonical do it? I've written about this in the context of Mir before, but it's worth expanding on the general case. The FSF's copyright assignment ensures that contributions to GPLed software will only be distributed under GPL-style licenses. The Apache CLA permits the ASF to relicense a contribution under a proprietary license, but the Apache license allows anyone to do that anyway. Going through Wikipedia's list of CLA users, the majority cover projects that are under BSD- or Apache-style licenses, with a couple of cases covering GPLed projects with a promise that any contributions will only be distributed under GPL-like licenses[1]. Either everyone can produce proprietary derivative works, or nobody can.

In contrast, Canonical ship software under the GPLv3 family of licenses (GPL, AGPL and LGPL) but require that contributors sign an agreement that permits Canonical to relicense their contributions under a proprietary license. This is a fundamentally different situation to almost all widely accepted CLAs, and it's disingenuous for Canonical to defend their CLA by pointing out the broad community uptake of, for instance, the Apache CLA.

Canonical could easily replace their CLA with one that removed this asymmetry - Project Harmony, the basis of Canonical's CLA, permits you to specify an "inbound equals outbound" agreement that prevents upstream from relicensing under a proprietary license[2]. Canonical's deliberate choice not to do so just strengthens the argument that the CLA is primarily about wanting to produce proprietary versions of software rather than wanting to strengthen their case in any copyright or patent disputes. It's unsurprising that people feel disinclined to contribute to projects under those circumstances, and it's difficult to understand why Canonical simultaneously insist on this hostile behaviour and bemoan the lack of community contribution to Canonical projects.

[1] The one major exception is the Digia/Qt project CLA, which covers an LGPLed work but makes it entirely clear that Digia will ship your contributions under proprietary licenses as well. At least they're honest.

[2] See the various options in section 2.1(d) here. Canonical chose option five. If they'd chosen option one instead, this wouldn't be a problem.

comments

A new major release 0.4.0 of RProtoBuf, is now on CRAN. RProtoBuf provides GNU R bindings for the Google Protocol Buffers ("Protobuf") data encoding library used and released by Google, and deployed as a language and operating-system agnostic protocol by numerous projects. With this release, we are welcoming Jeroen Ooms to the team. Jeroen had already worked on some RProtoBuf extensions in the context of his OpenCPU project; we have now integrated those Protocol Buffers functions. And Jeroen pushed all the right buttons to finally get RProtoBuf built on everybody's least-favourite operating system by provding a static library for use by win-builder and CRAN. Murray once again did a lot of work on internals. His use of the LLVM tool llvm-format was particular helpful to make our coding style a little more consistent. The complete NEWS file entry for this release follows:

Changes in RProtoBuf version 0.4.0 (2014-01-14)

• Changes to support CRAN builds for MS Windows.
• Added functions serialize_pb, unserialize_pb, and can_serialize_pb plus documentation from Jeroen Ooms RProtoBufUtils package.
• New dir inst/python with some Python examples.
• Added Jeroen Ooms as author.
• Vignettes have been converted to the R 3.0.0 or later use of external vignette builders, no longer need a Makefile
• Added missing methods to dollar completion list for Message, Descriptor, EnumValueDescriptor, and FileDescriptor classes.
• Add missing export for .DollarNames EnumValueDescriptor to allow completion on that class.
• Add more than 15 additional pages to the main Intro vignette documenting better all of the S4 classes implemented by RProtoBuf, updating the type mapping tables to take into account 64-bit support, and documenting advanced features such as Extensions.
• Added better error checking in EnumDescriptors to catch the case when wrong types are provided.
• Updated the FileDescriptor name() method to accept a boolean for full paths just like the generic name() method.
• Correct a bug that incorrectly dispatched as.character() when as.list() was called on Descriptor objects.
• Update FileDescriptor $ dispatch to work properly for the names of fields defined in the FileDescriptor, instead of just returning NULL even for types returned by $ completion.
• Added a reservation for extension fields in the example tutorial.Person schema.
• Support setting int32 fields with character representations and raise an R-level stop() error if the provided string can not be parsed as a 32-bit integer, rather than crashing the R instance.
• Update the project TODO file.
• Add better documentation and tests for all of the above.
• Corrected the handling of uint32 and fixed32 types in protocol buffers to ensure that they work with numbers as large as 2^32 - 1, which is larger than an integer can hold in R since R does not have an unsigned integer class. These values are stored as doubles internally now to avoid losing precision.
• Added unit tests to verify behavior of RProtoBuf with extreme values for uint32 types.
• Removed old exception handling code and instead rely on the more modern Rcpp::stop method maintained in Rcpp.
• Add better error messages when setting a repeated field of messages to inform the user which element index was of the wrong type and what the expected type was.
• Add an optional 'partial' argument to readASCII allowing uninitialized message fragments to be read in.
• (internal) Added const qualifiers in more places throughout the C++ code for type safety.
• (internal) Standardize coding conventions of the C++ files and run them through clang-format for consistency. A STYLE file has been submitted to R-Forge with details about the coding standards and how they are enforced with Emacs and clang-format.
• Applied changes suggested by Kevin Ushey to the S4 class handling to support both the currently released Rcpp as well as the currently pending next version.

CRANberries also provides a diff to the previous release 0.3.2. More information is at the RProtoBuf page which has a draft package vignette, a 'quick' overview vignette and a unit test summary vignette. Questions, comments etc should go to the rprotobuf mailing list off the RProtoBuf page at R-Forge.

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. Please report excessive re-aggregation in third-party for-profit settings.

While writing this post, I recognize that we might need a news-blog for Tanglu Since yesterday, we have an (installable!) Beta2 release of Tanglu! Compared to the previous snapshot, it comes with a huge amount of improvements and bugfixes:

• The systemd journal is now used for logging exclusively. You can install rsyslog to get the old behaviour back, and switch the journal to non-persistent mode. If you want to test the journal, type journalctl -b to get all messages from last boot. If we experience issues, we might revert to rsyslog for the final release.
• KDE received a new theming for KDM/KSplash, so we can now show a face-browser in KDM, which is considered more user-friendly. User faces are now loaded from the user s settings, instead of system directories by default. If you want to load a large user list (> 100) over network, you might not want this, but in that case you can easily revert the change.
• Tanglu does no longer include an MTA by default. If you want one, install one and configure it. On desktop systems, having an MTA makes no sense, especially when it is not properly configured (we follow Ubuntu/Fedora here).
• We ship with a functional live-installer now! You can install Tanglu easily to try it out. Unfortunately, the Debian installer is still not working, so you will have to boot into the live session to install Tanglu.
• GNOME is now working. GDM and g-s-d will no longer crash, and Mutter is able to utilize llvmpipe for rendering in a virtual machine. The Shell and various other GNOME parts were updated to GNOME 3.10
• We now ship the 1.14 version of Xorg now
• Linux 3.12 is now default

Known issues:

• People with ATi graphics cards might have trouble with installing the proprietary fglrx driver
• In some very rare cases, the live-cd won t auto-login. In that case, just reboot and try again, or use the password live to access the account.
• Some packages are not installable, there is a list compiled here, with detailed info why they are broken (they will be removed from the release if they are not fixed) Some transitions are still pending (causes broken/not-coinstallable packages)
• Users with a non-English locale will have an additional Public folder in their home-directory on KDE
• We don t support UEFI at time, please use the legacy mode to boot
• We just noticed that the GNOME images won t start the GNOME-Session for some reason. [UPDATE:21.01]: We published new live-cd images which have this issue fixed.

You can download the release from one of these mirrors: Mirror1 Mirror2 Mirror3 Additionally, there is now a release schedule for Tanglu Aequorea, and we will do a vote on the name for the next release soon (proposed names). As a note to Debian: systemd is working pretty well for Tanglu so far I am pretty happy with this Beta2 release, because Tanglu is shaping out to be the distribution we imagined in the beginning. Have fun! And as bonus, here are some images from Beta2:

Now it is time for me to go silent for a while, and not talk about jobs, unemployment, or puppies. This past week has also been full of software releases. Some of the public ones include:

Lumail - My console mail client, with integrated lua scripting

After three months of slow work I've issued a new release today. This release features several bugfixes for dealing with malformed MIME messages, and similar fun. The core set of lua primitives hasn't changed very much for a good six months now, which means I guess rightly what kind of things would be useful.

Templer - My perl-based static-site generator.

This was recently updated to add two new plugins to the core:

• A redis plugin to allow you to set variables to values retrieved from redis.
• An RSS plugin to allow you to inline (remote) RSS feeds into your static HTML. Useful for building news-pages, etc.

Although there are a million static-site generators I still think mine has value, and I am consistently using it.

Months ago when I said "I'm writing a mail-client", all I need to do is handle three cases:

• Display a list of folders.
• Display index of messages.
• Display a single message.

Then some new things like "Compose", "Reply", "Forward", I remember somebody commented along the lines of "Yeah, but MIME will make you hate your life" I laughed. Now I know better. Still it works, it works well, and I'm glad I did it.

I was back at my parents' over Christmas, like usual. Before I got back my Dad had mentioned they'd been having ADSL stability issues. Previously I'd noticed some issues with keeping a connection up for more than a couple of days, but it had got so bad he was noticing problems during the day. The eventual resolution isn't going to surprise anyone who's dealt with these things before, but I went through a number of steps to try and improve things. Firstly, I arranged for a new router to be delivered before I got back. My old Netgear DG834G was still in use and while it didn't seem to have been the problem I'd been meaning to get something with 802.11n instead of the 802.11g it supports for a while. I ended up with a TP-Link TD-W8980, which has dual band wifi, ADSL2+, GigE switch and looked to have some basic OpenWRT support in case I want to play with that in the future. Switching over was relatively simple and as part of that procedure I also switched the ADSL microfilter in use (I've seen these fail before with no apparent cause). Once the new router was up I looked at trying to get some line statistics from it. Unfortunately although it supports SNMP I found it didn't provide the ADSL MIB, meaning I ended up doing some web scraping to get the upstream/downstream sync rates/SNR/attenuation details. Examination of these over the first day indicated an excessive amount of noise on the line. The ISP offer the ability in their web interface to change the target SNR for the line. I increased this from 6db to 9db in the hope of some extra stability. This resulted in a 2Mb/s drop in the sync speed for the line, but as this brought it down to 18Mb/s I wasn't too worried about that. Watching the stats for a further few days indicated that there were still regular periods of excessive noise, so I removed the faceplate from the NTE5 master BT socket, removing all extensions from the line. This resulted in regaining the 2Mb/s that had been lost from increasing the SNR target, and after watching the line for a few days confirmed that it had significantly decreased the noise levels. It turned out that the old external ringer that was already present on the line when my parents' moved in was still connected, although it had stopped working some time previously. Also there was an unused and much spliced extension in place. Removed both of these and replacing the NTE5 faceplate led to a line that was still stable. At the time of writing the connection has been up since before the new year, significantly longer than it had managed for some time. As I said at the start I doubt this comes as a surprise to anyone who's dealt with this sort of line issue before. It wasn't particularly surprising to me (other than the level of the noise present), but I went through each of the steps to try and be sure that I had isolated the root cause and could be sure things were actually better. It turned out that doing the screen scraping and graphing the results was a good way to verify this. Observe: The blue/red lines indicate the SNR for the upstream and downstream links - the initial lower area is when this was set to a 6db target, then later is a 9db target. Green are the forward error correction errors divided by 100 (to make everything fit better on the same graph). These are correctable, but still indicate issues. Yellow are CRC errors, indicating something that actually caused a problem. They can be clearly seen to correlate with the FEC errors, which makes sense. Notice the huge difference removing the extensions makes to both of these numbers. Also notice just how clear graphing the data makes things - it was easy to show my parents' the graph and indicate how things had been improved and should thus be better.

This is mostly a repost of my ubuntu-devel mail for a wider audience, but see below for some additions. I'd like to upgrade to GRUB 2.02 for Ubuntu 14.04; it's currently in beta. This represents a year and a half of upstream development, and contains many new features, which you can see in the NEWS file. Obviously I want to be very careful with substantial upgrades to the default boot loader. So, I've put this in trusty-proposed, and filed a blocking bug to ensure that it doesn't reach trusty proper until it's had a reasonable amount of manual testing. If you are already using trusty and have some time to try this out, it would be very helpful to me. I suggest that you only attempt this if you're comfortable driving apt-get directly and recovering from errors at that level, and if you're willing to spend time working with me on narrowing down any problems that arise. Please ensure that you have rescue media to hand before starting testing. The simplest way to upgrade is to enable trusty-proposed, upgrade ONLY packages whose names start with "grub" (e.g. use apt-get dist-upgrade to show the full list, say no to the upgrade, and then pass all the relevant package names to apt-get install), and then (very important!) disable trusty-proposed again. Provided that there were no errors in this process, you should be safe to reboot. If there were errors, you should be able to downgrade back to 2.00-22 (or 1.27+2.00-22 in the case of grub-efi-amd64-signed). Please report your experiences (positive and negative) with this upgrade in the tracking bug. I'm particularly interested in systems that are complex in any way: UEFI Secure Boot, non-trivial disk setups, manual configuration, that kind of thing. If any of the problems you see are also ones you saw with earlier versions of GRUB, please identify those clearly, as I want to prioritise handling regressions over anything else. I've assigned myself to that bug to ensure that messages to it are filtered directly into my inbox. I'll add a couple of things that weren't in my ubuntu-devel mail. Firstly, this is all in Debian experimental as well (I do all the work in Debian and sync it across, so the grub2 source package in Ubuntu is a verbatim copy of the one in Debian these days). There are some configuration differences applied at build time, but a large fraction of test cases will apply equally well to both. I don't have a definite schedule for pushing this into jessie yet - I only just finished getting 2.00 in place there, and the release schedule gives me a bit more time - but I certainly want to ship jessie with 2.02 or newer, and any test feedback would be welcome. It's probably best to just e-mail feedback to me directly for now, or to the pkg-grub-devel list. Secondly, a couple of news sites have picked this up and run it as "Canonical intends to ship Ubuntu 14.04 LTS with a beta version of GRUB". This isn't in fact my intent at all. I'm doing this now because I think GRUB 2.02 will be ready in non-beta form in time for Ubuntu 14.04, and indeed that putting it in our development release will help to stabilise it; I'm an upstream GRUB developer too and I find the exposure of widely-used packages very helpful in that context. It will certainly be much easier to upgrade to a beta now and a final release later than it would be to try to jump from 2.00 to 2.02 in a month or two's time. Even if there's some unforeseen delay and 2.02 isn't released in time, though, I think nearly three months of stabilisation is still plenty to yield a boot loader that I'm comfortable with shipping in an LTS. I've been backporting a lot of changes to 2.00 and even 1.99, and, as ever for an actively-developed codebase, it gets harder and harder over time (in particular, I've spent longer than I'd like hunting down and backporting fixes for non-512-byte sector disks). While I can still manage it, I don't want to be supporting 2.00 for five more years after upstream has moved on; I don't think that would be in anyone's best interests. And I definitely want some of the new features which aren't sensibly backportable, such as several of the new platforms (ARM, ARM64, Xen) and various networking improvements; I can imagine a number of our users being interested in things like optional signature verification of files GRUB reads from disk, improved Mac support, and the TrueCrypt ISO loader, just to name a few. This should be a much stronger base for five-year support.

As explained in more detail in my my last blog post, Rackspace is providing hosting for Debian Code Search. For those of you who don t know, Rackspace is a cloud company that provides (among other services) a public cloud based on OpenStack. That means you can easily (and programmatically, if you want) bring up virtual servers, block storage volumes, configure the network between them, etc. As part of my initial performance experiments, I was running debmirror to clone a full Debian source mirror, and I noticed this took about one hour. Given that the peak network and storage write rates I have observed in my benchmarks are much higher, I wondered why it took so long. About 43 GB (that s how big the Debian sid sources are) in 60 minutes means 12 MB/s download rate, which is a bit more than a sustained 100 MBit/s connection. Luckily, at least the Rackspace servers I looked at are connected with 1 GBit/s to the internet, so more should be possible. Note that these are the old Rackspace servers. There is a new generation of servers, which I have not yet tried, that apparently offer even higher performance. After a brief look at the debmirror source code, I concluded that it can only use a single mirror and downloads files sequentially. There is some obvious potential for improvement here, and the fact that I could come up with a proof of concept written in Go to determine the files to download in a couple of minutes encouraged me to spend my saturday on this problem :-). About 7 hours later, my prototype had gone through various iterations and the code could sustain about 115 MB/s incoming bandwidth for most of the time. Here is a screenshot of dstat measuring the performance: Another 3 hours later, the most obvious bugs were weeded out and the code successfully cloned an entire mirror for the first time. I verified the correctness by running debmirror afterwards, and no files were downloaded that had not actually arrived on the mirror in the meantime. Features

1. Parallel downloading from multiple mirrors.
   Of course, it is not guaranteed that the mirrors are consistent, but that is a solvable problem: whenever a non-200 HTTP response is encountered, the file is put back into the queue and gets rescheduled onto any mirror. Eventually, it will be rescheduled onto the mirror from which the sources.gz was downloaded, and that mirror has to have it.
2. HTTP keep-alive and pipelining.
   debmirror also does HTTP keep-alive (I read that in the source, did not verify it), but it downloads files sequentially, i.e. it downloads one file, then sends the request for the next file. This means that after one file was received, no data is being received until another round-trip finished. For a lot of small files (think of .dsc and .debian.tar.gz files or small orig tarballs) that really adds up.
   Therefore, I use HTTP pipelining: I send 99 requests and then just receive all the responses at full speed. The magic number 99 comes from the fact that this is the smallest common denominator that all mirrors I have tested allow. nginx by default allows 100 requests.
3. Request ordering.
   Instead of sending requests at random, I sort the download queue by size and make sure that the first request on each connection is for a big file. The intention is that TCP will adapt to that quickly and use a bigger window size as soon as possible instead of ramping up slower later on. Note that I have not actually measured the window sizes, so this is just a hunch.
   Another nice side-effect of the ordering is that the amount of data that is being sent through each connection is roughly equal. This means we don t waste TCP connections by sending 99 requests for small files only.
4. (Goroutines).
   I m a bit hesitant to even write about it, so let s make it quick: Perl (and thus debmirror) is typically single-threaded, whereas Goroutines scale nicely on multi-core systems. I don t think it makes a big difference on the machines I am running this on as they have only two cores and are not maxed out on CPU usage at all. But maybe this will be more important for saturating 10 GBit/s? :-)
5. (Mirror selection).
   It s not a feature of the code, but certainly relevant: of course I selected mirrors that are connected to the internet with at least a Gigabit link, serve files reasonably fast and have low latency to Rackspace s Chicago presence.
   Interestingly, while I used to think that universities have access to big uplinks and beefy machines, none of the mirrors that I use are located at a university. In fact, every mirror ending in .edu that I tried was really slow most of them providing something like 2-4 MB/s.

Results With the latest iteration of the code, I can clone an entire Debian source mirror with 43 GB of data in about 11.5 minutes, which corresponds to a 63 MB/s download rate:

GOMAXPROCS=20 ./dcs-debmirror -num_workers=20
68,24s user 384,90s system 66% cpu 11:25,97 total

It should be noted that the download rate is very low in the first couple of seconds since the sources.gz file is downloaded from a single mirror, then unpacked and analyzed. The peak download rate is about 115 MB/s (= 920 MBit/s) which is reasonably close at what you can achieve with a Gigabit link, I think. If the entire uplink was available to me at all time, the Rackspace hardware would be able to saturate that easily, both in terms of reading from the network and in terms of writing to block storage. I tested this on an SSD volume, but I see about 113 MB/s throughput with the internal hard disk, so I think that should work, too. There is another dstat screenshot of the final version (writing to disk). Perhaps even more interesting to some readers is the time for an incremental update:

GOMAXPROCS=20 ./dcs-debmirror -tcp_conns=20
2013/10/13 11:09:55 Downloading 307 files (447 MB total)
 
2013/10/13 11:10:04 All 307 files downloaded in 9.105605931s. Download rate is 49.186567 MB/s
4,91s user 3,99s system 67% cpu 13,205 total

The wall clock time is higher than the time reported by the code because the code does not count the time for downloading and parsing the sources.gz file. The entire program is about 400 lines (not SLOC) of Go code. It s part of the Debian Code Search source. If you re interested, you can read dcs-debmirror.go in your browser. Conclusions The outcome of this experiment is that I now know (and have shown!) that there are significantly more efficient ways of cloning a Debian mirror than what debmirror does. Furthermore, I have a good grasp on what kind of performance the Rackspace cloud offers and I am fairly happy with the numbers :-). My code is useful to me in context of Debian Code Search, but unless you need a sid-only source-only mirror, it will not be useful to you directly. Of course you can take the ideas that I implemented and implement them elsewhere personally, I don t plan to do that. If you have hardware, bandwidth and a use-case for 10 GBit/s+ mirroring, I d like to hear about it! :-)

Somalia's chief exports appear to be morally-ambiguous Salon articles about piracy and sophomoric evidence against libertarianism. However, it is the former topic that Captain Phillips concerns itself with, inspired by the hijacking of the Maersk Alabama container ship in 2009. What is truth? In the end, Captain Phillips does not rise above Pontius Pilate in providing an answer, but it certainly tries using more refined instruments than irony or leaden sarcasm. This motif pervades the film. Obviously, it is based on a "true story" and brings aboard that baggage, but it also permeates the plot in a much deeper sense. For example, Phillips and the US Navy lie almost compulsively to the pirates, whilst the pirates only really lie once (where they put Phillips in greater danger). Notice further that Phillips only starts to tell the truth when he thinks all hope is lost. These telling observations become even more fascinating when you realise that they must be based on the testimony of the, well, liars. Clearly, deception is a weapon to be monopolised and there are few limits on what good guys can or should lie about if they believe they can save lives. Futhermore, there is an utterly disarming epilogue where Phillips is being treated for shock by clinical efficient medical staff. Not only will this scuttle any "blanket around the shoulders" clich but is probably a highly accurate portrayal of what actually happens post-trauma. This echoes the kind of truth Werner Herzog aims for in his filmmaking as well his guilt-inducing duality between uncomfortable lingering and compulsive viewing. Lastly, a starter for a meta-discussion: can a film based on real-world events even be "spoilered"? Hearing headlines on the radio before you read your newspaper hardly robs you of a literary journey... Captain Phillips does have some quotidian problems. Firstly, the only tool for ratcheting up tension is for the Somalians to launch verbal broadsides at the Americans, with each compromise somehow escalating the situation. This technique is effective but well before the climatic rescue scene where it is really needed it has been subject to the most extreme diminishing returns. (I cannot be the first to notice the "Africans festooned with guns shouting incomphensively" trope I hope it is based on a Babel-esque mechanism of disorientation from miscommunication rather than anything more unsavoury.) Secondly, the US Navy acts like a teacher with an Ofsted inspector observing quietly from the corner of the classroom; far too well-behaved it suspends belief, with no post-kill gloating or even the tiniest of post-arrest congratulations. Whilst nobody wants to see the Navy overreact badly to other military branches getting all the glory, nobody wants to see a suspiciously bland recruitment vehicle either. Paradoxically, this hermetic treatment made me unduly fascinated by them as if they were part of some military "uncanny valley". Two quick observations:

• All US Somali interactions are recorded by a naval officer. No doubt a value-for-money defense against a USS Abu Ghraib, but knowing the plot is based on factual events, it was perhaps a little too Baudrillardian to ponder how the presence of the Navy's cameras in a scene actually lent weight to the film's version of events, crucially without me even knowing whether the parallel "real-life" footage is verifiable or not.
• The navigational computers not only seem to require lines to drawn repeatedly between points of interest, but the Maersk Alabama's arbitrary relabelling as MOTHERSHIP seems to imply that an officer could humourously rename a radar contact to something unbecoming of a 12A classification.

Finally, despite the title, the film is actually about two captains; the skillful liar Phillips and ... well, that's the real problem. Whilst Captain Muse is certainly no caricatured Hook, we are offered little depth beyond a "You're not just a fisherman" faux-revelation that leads nowhere. I was left inventing reasons for his akrasia so that he made any sense whatsoever. One could charitably argue that the film attempts to stay objective on Muse, but the inability for the film to take any obvious ethical stance actually seems to confuse and then compromise the narrative. What deeper truth is actually being revealed? Is this film or documentary? Worse still, the moral vacuum is invariably filled by the viewer's existing political outlook: are Somali pirates victims of circumstance who are forced into (alas, regrettable) swashbuckling adventures to pacify plank-threatening warlords? Or are they violent and dangerous criminals who habour an irrational resentment against the West, flimsily represented by material goods in shipping containers? Your improvised answer to this Rorschach test will always sit more haphazardly in the film than any pre-constructed treatment ever could. 6/10

Somalia's chief exports appear to be morally-ambiguous Salon articles about piracy and sophomoric evidence against libertarianism. However, it is the former topic that Captain Phillips concerns itself with, inspired by the hijacking of the Maersk Alabama container ship in 2009. What is truth? In the end, Captain Phillips does not rise above Pontius Pilate in providing an answer, but it certainly tries using more refined instruments than irony or leaden sarcasm. This motif pervades the film. Obviously, it is based on a "true story" and brings aboard all that well-travelled baggage, but it also permeates the plot in a much deeper sense. For example, Phillips and the US Navy lie almost compulsively to the pirates, whilst the pirates only really lie once where they put Phillips in greater danger. Notice further that Phillips only starts to tell the truth when he thinks all hope is lost. These telling observations become even more fascinating when you realise that they must be based on the testimony of the, well, liars. Clearly, deception is a weapon to be monopolised and there are few limits on what good guys can or should lie about if they believe they can save lives. Lastly, there is an utterly disarming epilogue where Phillips is being treated for shock by clinical efficient medical staff. Not only will it scuttle any "blanket around the shoulders" clich but is probably a highly accurate portrayal of what actually happens post-trauma. This echoes the kind of truth Werner Herzog often aims for in his filmmaking as well his guilt-inducing duality between uncomfortable lingering and compulsive viewing. Another angle worthy of discussion: can a film based on real-world events even be "spoilered"? Hearing headlines on the before you read the newspaper hardly robs you of a literary journey... Captain Phillips does have some quotidian problems. Firstly, the only tool for ratcheting up tension is for the Somalians to launch verbal broadsides at the Americans, with each compromise somehow escalating the situation further. This technique is genuinely effective but well before the climatic rescue scene where it is really needed it has been subject to the most extreme diminishing returns. (I cannot be the first to notice the "Africans festooned with guns shouting incomphensively" trope I hope it is based on a Babel-esque mechanism of disorientation and miscommunication rather than anything, frankly, unsavoury.) Secondly, the US Navy acts like a teacher with an Ofsted inspector observing quietly from the corner of the classroom; far too well-behaved it suspends belief, with no post-kill gloating or even the tiniest of post-arrest congratulations. Whilst nobody wants to see the Navy overreact badly to other military branches getting all the glory, nobody wants to see a suspiciously bland recruitment vehicle either. Paradoxically, this hermetic treatment made me unduly fascinated by them, as if they were part of some military "uncanny valley". Two quick observations:

• All US Somali interactions are recorded by a naval officer. No doubt a value-for-money defense against a USS Abu Ghraib, but knowing the plot is based on a factual events, it was perhaps a little too Baudrillardian to ponder how the presence of the Navy's cameras in a scene actually lent weight to the film's version of events, crucially without me even knowing whether the parallel "real life" footage is verifiable or not.
• The navigational computers not only seem to require lines to drawn repeatedly between points of interest, but the Maersk Alabama's arbitrary relabelling as MOTHERSHIP seems to imply that an officer could humourously rename a contact to something unbecoming of a 12A classification.

Finally, despite the title, the film is actually about two captains; the skillful liar Phillips and ... well, that's the real problem. Whilst Captain Muse is certainly no caricatured Hook, we are offered little depth beyond a "You're not just a fisherman" faux-revelation that leads nowhere. I was left inventing reasons for his akrasia so that he made any sense whatsoever. One could charitably argue that the film attempts to stay objective on Muse, but the inability for the film to take any obvious ethical stance actually seems to confuse and then compromise the narrative. What deeper truth is actually being revealed? Is this film or documentary? Worse still, the moral vacuum is invariably filled by the viewer's existing political outlook: are Somali pirates victims of circumstance who are forced into (alas, regrettable) swashbuckling adventures to pacify plank-threatening warlords? Or are they violent and dangerous criminals who habour an irrational resentment against the West, flimsily represented by material goods in shipping containers? Your improvised answer to this Rorschach test will always sit more haphazardly in the film than any pre-constructed treatment ever could. 6/10

One of my pet projects in Debian is the Debian Maintainer Dashboard. Built on top of UDD, DMD provides a maintainer-centric view to answer the I have a few hours for Debian, what should I do now? question (see example). Christophe Siraut did a lot of great work recently on DMD, rewriting much of the internals. As a result, he also added a RSS feed feature: you can now get notified of new TODO list items by subscribing to that feed. If you have suggestions or comments, please use the debian-qa@ list (see this thread). Thanks, Christophe!

I recently found, that the automount feature of my recent Debian Sid / GNOME 3 system didn't work anymore. For example: I plugged in an USB stick. Nothing happened, although dmesg clearly showed, that the system recognized it. After manually mounting and unmounting the device, nautilus automatically offered to automount it. But I always had to manually mount and unmount it first. Seems the culprit was a pmount installation. JFTR: In some cases also usbmount might cause trouble.

Coverity is a nice tool to find problems in C, C++ and Java code using static source code analysis. It can detect a lot of different problems, and is very useful to find memory and locking bugs in the error handling part of the source. The company behind it provide check of free software projects as a community service, and many hundred free software projects are already checked. A few days ago I decided to have a closer look at the Coverity system, and discovered that the gnash and ipmitool projects I am involved with was already registered. But these are fairly big, and I would also like to have a small and easy project to check, and decided to request checking of the chrpath project. It was added to the checker and discovered seven potential defects. Six of these were real, mostly resource "leak" when the program detected an error. Nothing serious, as the resources would be released a fraction of a second later when the program exited because of the error, but it is nice to do it right in case the source of the program some time in the future end up in a library. Having fixed all defects and added a mailing list for the chrpath developers, I decided it was time to publish a new release. These are the release notes: New in 0.16 released 2014-01-14:

• Fixed all minor bugs discovered by Coverity.
• Updated config.sub and config.guess from the GNU project.
• Mention new project mailing list in the documentation.

You can download the new version 0.16 from alioth. Please let us know via the Alioth project if something is wrong with the new release. The test suite did not discover any old errors, so if you find a new one, please also include a test suite check.

X bitmaps vs OpenGL Of course, you all know that X started life as a monochrome window system for the VS100. Back then, bitmaps and rasterops were cool; you could do all kinds of things simple bit operations. Things changed, and eventually X bitmaps became useful only off-screen for clip masks, text and stipples. These days, you ll rarely see anyone using a bitmap everything we used to use bitmaps for has gone all alpha-values on us. In OpenGL, there aren t any bitmaps. About the most bitmap-like object you ll find is an A8 texture, holding 8 bits of alpha value for each pixel. There s no way to draw to or texture from anything where each pixel is represented as a single bit. So, as Eric goes about improving Glamor, he got a bit stuck with bitmaps. We could either:

• Support them only on the CPU, uploading copies as A8 textures when used as a source in conjunction with GPU objects.
• Support them as 1bpp on the CPU and A8 on the GPU, doing fancy tracking between the two objects when rendering occurred.
• Fix the CPU code to deal with bitmaps stored 8 bits per pixel.

I thought the latter choice would be the best plan directly share the same object between CPU and GPU rendering, avoiding all reformatting as things move around in the server. Why is this non-trivial? Usually, you can flip formats around with reckless abandon in X, it has separate bits-per-pixel and depth values everywhere. That s how we do things like 32 bits-per-pixel RGB surfaces; we just report them as depth 24 and everyone is happy. Bitmaps are special though. The X protocol has separate (and overly complicated) image formats for single bit images, and those have to be packed 1 bit per pixel. Within the server, bitmaps are used for drawing core text, stippling and creating clip masks. They re the lingua franca of image formats, allowing you to translate between depths by pulling a single plane out of a source image and painting it into a destination of arbitrary depth. As such, the frame buffer rendering code in the server assumes that bitmaps are always 1 bit per pixel. Given that it must deal with 1bpp images on the wire, and given the history of X, it certainly made sense at the time to simplify the code with this assumption. A blast from the past I d actually looked into doing this before. As part of the DECstation line, DEC built the MX monochrome frame buffer board, and to save money, they actually created it by populating a single bit in each byte rather than packed into 8 pixels per byte. I have this vague memory that they were able to use only 4 memory chips this way. The original X driver for this exposed a depth-8 static color format because of the assumptions made by the (then current) CFB code about bitmap formats. Jim Gettys wandered over to MIT while the MX frame buffer was in design and asked how hard it would be to support it as a monochrome device instead of the depth-8 static color format. At the time, fixing CFB would have been a huge effort, and there wasn t any infrastructure for separating the wire image format from the internal pixmap format. So, we gave up and left things looking weird to applications. Hacking FB These days, the amount of frame buffer code in the X server is dramatically less; CFB and MFB have been replaced with the smaller (and more general) FB code. It turns out that the number of places which need to deal with individual bits in a bitmap are now limited to a few stippling and CopyPlane functions. And, in those functions, the number of individual read operations from the bitmap are few in number. Each of those fetches looked like:

bits = READ(src++)

All I needed to do was make this operation return 32 bits by pulling one bit from each of 8 separate 32-bit chunks and merge them together. The first thing to do was to pad the pixmap out to a 32 byte boundary, rather than a 32 bit boundary. This ensured that I would always be able to fetch data from the bitmap in 8 32-bit chunks. Next, I simply replaced the READ macro call with:

    bits = fb_stip_read(src, srcBpp);
    src += srcBpp;

The new fb_stip_read function checks srcBpp and packs things together for 8bpp images:

/*
 * Given a depth 1, 8bpp stipple, pull out
 * a full FbStip worth of packed bits
 */
static inline FbStip
fb_pack_stip_8_1(FbStip *bits)  
    FbStip      r = 0;
    int         i;
    for (i = 0; i < 8; i++)  
        FbStip  b;
        uint8_t p;
        b = FB_READ(bits++);
#if BITMAP_BIT_ORDER == LSBFirst
        p = (b & 1)   ((b >> 7) & 2)   ((b >> 14) & 4)   ((b >> 21) & 8);
        r  = p << (i << 2);
#else
        p = (b & 0x80000000)   ((b << 7) & 0x40000000)  
            ((b << 14) & 0x20000000)   ((b << 21) & 0x10000000);
        r  = p >> (i << 2);
#endif
     
    return r;
 
/*
 * Return packed stipple bits from src
 */
static inline FbStip
fb_stip_read(FbStip *bits, int bpp)
 
    switch (bpp)  
    default:
        return FB_READ(bits);
    case 8:
        return fb_pack_stip_8_1(bits);
     
 

It turns into a fairly hefty amount of code, but the number of places this ends up being used is pretty small, so it shouldn t increase the size of the server by much. Of course, I ve only tested the LSBFirst case, but I think the MSBFirst code is correct. I ve sent the patches to do this to the xorg-devel mailing list, and they re also on the depth1 branch in my repository

git://people.freedesktop.org/~keithp/xserver.git

Testing Eric also hacked up the test suite to be runnable by piglit, and I ve run it in that mode against these changes. I had made a few mistakes, and the test suite caught them nicely. Let s hope this adventure helps Eric out as he continues to improve Glamor.

Having decided to take a fortnight off, between looking for a new job, I assumed I'd spend a while coding. Happily my wife, who is a (medical) doctor, has been home recently so we've got to spend time together instead. I'm currently pondering projects which will be small enough to be complete in a week, but large enough to be useful. Thus far I've just reimplemented RSS -> chat which I liked a lot at Bytemark. I have my own chat-server setup, which doesn't have any users but myself. Instead it has a bunch of rooms setup, and different rooms get different messages. I've now created a new "RSS" room, and a bunch of RSS feeds get announced there when new posts appear. It's a useful thing if you like following feeds, and happen to have a chat-room setup. I use Prosody as my chat-server, and I use my http2xmpp code to implement a simple HTTP-POST to XMPP broadcast mechanism. The new script is included as examples/rss-announcer and just polls RSS feeds - URLs which haven't been broadcast previously are posted to the HTTP-server, and thus get injected into the chatroom. A little convoluted, but simple to understand. This time round I'm using Redis to keep track of which URLs have been seen already. Beyond that I've been doing a bit of work for friends, and have recently setup an nginx server which will handle 3000+ simultaneous connections. Not too bad, but I'm sure we can make it do better - another server running on BigV which is nice to see :) I'll be handling a few Squeeze -> Wheezy upgrades in the next week too, setting up backups, and doing some other related "consultation". If I thought there was a big enough market locally I might consider doing that full-time, but I suspect that relying upon random work wouldn't work long-term.

Today (well, technically yesterday by now), the Media were reporting of an open letter by '5 belgian university professors from the IT field' without calling them by name about how Belgian primary education should introduce programming into the curriculum, starting at age 5. Unsurprisingly, this did not go well with a majority of the Belgian populace. Arguments like "what should the school drop to make place for that, then" and "why would people ever need to learn programming" were rampant on some internet fora that I had a short look at. That being said, though, I think these five unnamed professors are correct. Understanding how a tool works is essential to proficient usage of said tool; and while it is possible to teach particular common and popular use cases of a given tool without providing enough background, doing so will only result in confusion when the computer "is acting up" an oxymoron if there ever was one. After all, a computer can't "act up"; it can only follow instructions. Whenever your seems to be "acting up", what's really happening is that someone (most likely, you) gave it the wrong instructions. Or, perhaps, someone evil on the Internet gave it the right instructions (for their goals, anyway) and infected your computer with a virus. But that's unlikely. Computer education currently mostly consists of "teaching software": rather than explaining how a computer does what it does, people are taught that if you click this button, the text will be bold, or if you click that button, the printer will start buzzing. That's all nice and dandy, until the actual computer people encounter when off the school bench and at work has this other piece of software, where all the buttons are in other places and look all "wrong". Because then they get all confused about the fact that things aren't where they're supposed to be. So, yes, it is my opinion that any computer education should help people understand how a computer does the things it does. And what better way to do that than to actually explain things to a computer, the way computer programmers do such things? Note that programming a computer doesn't have to be hard, and it can be something which kids can understand and will find fun to do. For instance, there's this scratch thing from MIT, which was made for teaching programming in such a context. Yes, adding programming to the primary school curriculum will require that some other things are dropped instead, and I could see that being a problem. However, in our modern world computers have become so pervasively important that we would be doing our kids a disservice not to explain them how to understand computers, as opposed to just learn how to use them...