Author Archives: Andrew Sutherland

chroniquery does useful things!

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Before pecobro, there was chroniquery (shiny, also shiny, texty), a python binding for roc‘s chronicle-recorder omega-debugger.  Now, there is still chroniquery.  It just does more stuff, and does the stuff it previously did more correctly.

In any event, what the awesome ‘screenshot’ (it’s from a console…) shows:

  • A trace from running chronicle-recorder against xpcshell on amd64 running a gloda unit test.
  • Javascript being ‘traced’ with extraction of the function name, script, and line number… everything you’d expect from your dtrace probes or your JSD hooks/venkman/firebug…
  • Hm… it seems to know something about an XPConnect call going down…
  • Oh noes!  It has escaped into the C++ codes!

Thunderbird full-text search prototype a la SQLite FTS3

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Full-text search using FTS3.

Full-text search with a contact constraint.

The global database sqlite file resulting from indexing all of mozilla.dev.apps.thunderbird is about 13M for something like 4500 messages.  We’re providing FTS3 with the bodies (but not attachments!) of all the newsgroup messages and the subjects of the messages which initiate new threads.  For real usage, we will need to also index the subjects of each message.

Note that the message bodies have not been processed at all by the Thunderbird/gloda code before handing them off to FTS3.  So quoted messages get indexed even though it’s a lot of excess data.  We’re relying on FTS3 to do all stop-words, etc.  FTS3’s Porter stemming/tokenization is in use.

Thunderbird contact auto-completion… with bubbles!

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Autocompletion screenshot

Type type type type.  Autocomplete contact…

Completed contact becomes a bubble!  Bubble becomes a constraint, showing us only the messages involving the given contact.  (The idea is that you could then click on/select/whatever the bubble and change the constraint to be only to/from/cc/whatever if you are so inclined.)

Type type type, autocomplete, new constraint!  Now we’re looking at all the messages involving the two given contacts.  (Some of the messages with just one constraint were mailing list postings, but not explicitly involving the second contact.  This listing shows only messages where both contacts were directly involved.  We will have the ability to filter-out messages involving lists as desired, which may be desired by default in a case like this.)

What is exciting about this?

  • The contacts are matched using a suffix-tree implementation on a reduced set of contacts (as a first-pass).  In this case, those with sufficient ‘popularity’.  ‘Frecency’ a la ‘places’ is also planned.  And of course, we can hit the database as needed.  The suffix-tree is nice because it allows extremely rapid lookups while also allowing for substring matching.
  • The contact popularity is computed automatically by the gloda indexing process, taking into account both messages you receive and send.  (I think the current address-book code just increments popularity on send?)
  • I think the bubbles are cool.  (Hyperlink-styling would also work, but would not be cool.)
  • Having the text converted into an explicit object representation (bubbles) is better than just doing string filtering (as quicksearch does) because it allows explicit actions on the object given knowledge of the object type.
  • We can convert more than just contacts/identities to explicit objects.  As demonstrated at the summit, we have a plugin that detects bugzilla bug references in messages as well as (American/NANP-style) phone-numbers in messages.  We could detect these and promote them as well, etc.
  • The filtered messages are being delivered by gloda, the global database (backed by SQLite), which means that we aren’t searching just one folder.
  • There are a lot of places that you, the reader, will shortly be able to hack on and contribute to make this even more exciting.  A vicious cycle of exciting-ness will ensue until everyone is dancing in the streets.

gloda’s first (primitive) visualization

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Author activity over time, current thread in blue, selected message in darkest blue.

A primitive visualization augments the gloda “other messages by author” listing by showing the messages sent by the author over time.  Messages are stacked by day.  The currently selected message is in darkest blue and also very wide.  Other messages from the same thread/conversation are in lighter blue and less wide.  Messages not in the conversation are light grey and rather narrow.

It’s not clickable, it lacks any form of scale or any feedback at all, and there are scaling issues.  (If anyone wants to save me the effort of figuring out how to get the canvas to maintain a 1:1 pixel mapping to the actual display and still ‘flex’ by adding/losing pixels, please do drop me a message or leave a comment.)  These will all change, but not yet.

I’ve pushed the changes to the mercurial repos and updated the stable tag, but I’m not publishing updated xpi’s, so you’ll need to roll your own if you care.  (The DB schema has not changed and so does not need to be blown away.)

gloda milestone 1

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gloda m1 getting its indexing on

I am declaring milestone 1 of gloda (the global database extension for Thunderbird 3.x) / expmess (the experimental message view extension for Thunderbird 3.x) reached.  Milestone 1 basically consists of:

  • It statically indexes all of your folders.  It does not track changes made to your mailboxes.  It will become confused and angry as time goes on and your message stores change but it stays the same.  Thankfully, it is also passive aggressive and will merely stop doing useful things rather than trying to eat your data.  It also refuses to change its ways; if you try and trick it into indexing a message it has already processed but you moved, it will not update the message’s index.  You can, however, trick it into indexing new messages.
  • The indexing sorta happens in the background and has pretty, if dubious from an UX perspective, progress bars (see screenshot).  This was stolen from M3, making M1 wildly more usable than originally planned.  At least on my computer, I didn’t notice much performance impact from the indexing, but my system is arguably fairly beefy.  This can all be tweaked though, especially once we hook the nsIIdleService in.
  • It adds a “data mine” pane to the right side of the message window.  It has a splitter so you can hide it if you want, but you can never be rid of it.  The data mine shows you the other messages in the current thread and other messages sent by the author… globally!
  • If you double-click on a message in the “data mine” added by expmess, it will take you there!  This is stolen from M2.
  • It will print out a lot of debug on standard out.  It used to print more.

Having said all that, you can get the XPI’s here if you are using Thunderbird/Shredder 3.0a2pre or later, and your build is from July 5th 2008 or later.  You need to install both of them if you want anything interesting to happen.  The easiest way to do this is go to “Tools”…”Add-ons” in Shredder, and drag the links into the add-ons pane, at which point it will prompt you and such.  These extensions will not auto-update.

And the code (in mercurial) is here:

Because of the static indexing, you will probably want to install this extension, mention something about needing to wear sunglasses because of the brightness of the future, and then uninstall it.

Un-installation consists of:

  1. Disable / remove the gloda and expmess extensions.
  2. Delete the global-messages-db.sqlite file from your profile directory.  Or don’t.  It’s up to you.

I’ll be following this post up with a newsgroup post on mozilla.dev.apps.thunderbird on Monday with more details about planning out the rest of the milestones, as well as the arbitrary changes I had made to my (always tenative) milestone 1 plan.  Discussion about the global database is probably best directed to the newsgroup, but feel free to post comments here if you want too.

thunderbird global database m1-ish

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The ‘gloda’ (global database) and ‘expmess’ (experimental message view) Thunderbird extensions are nearly to milestone 1…

Thunderbird with gloda/expmess plugins m1-ish installed

The screenshot scenario is that we have 2 months of apache-dev archives in two separate folders, July and August.  We have a message selected in the month of July, yet the ‘data mine’ to the right is able to show the messages in the thread spanning both months (and therefore folders), as well as showing all the other messages sent by the author spanning both months (and therefore folders).

I’ll post again with some links and what not once I hit the actual milestone 1.  Be aware that every-day usability is targeted for milestone 3, but that should still happen pre-summit.

pecobro, the tell-you-who-reads/writes-what performance code browser

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No cool pictures, but I’ve enhanced and exposed the global reader/writer understanding of javascript code.  In other words, pecobro now does a passable job at telling you what global variables a given javascript file reads from/writes to, and who else writes to/reads from those variables.  False negatives are expected (don’t rely on things to be exhaustive), and false positives are quite conceivable.

As an example starting point, take a look at messageWindow.js’s global reads or global writes.  From either of these you can click on other files in the sidebar to go to them.  There is no execution trace, so the overview diagram won’t be any help.  Be sure you have some free memory available and won’t try and hurt me if Firefox does something crazy.  Note: for long documents, some delay is expected as it attempts to apply various fix-ups.  Also note: clicking on things in the global reads/global writes tab won’t get you anywhere for now.

A quick example of a global read from that file (and who writes to that global):

gDBView

  • Top Level: commandglue.js
  • Function: ClearThreadPane (in commandglue.js)
  • Function: CreateBareDBView (in commandglue.js)
  • Function: RerootFolder (in commandglue.js)
  • Function: SwitchView (in commandglue.js)
  • Function: openFolderTab (in mailWindowOverlay.js)
  • Function: setMailTabState (in mailWindowOverlay.js)
  • Function: restorePreSearchView (in searchBar.js)
  • Function: MsgGroupBySort (in threadPane.js)

A quick example of a global write from that file (and who reads from that global):

SelectFolder

  • Function: OpenMessageByHeader (in mailContextMenus.js)
  • Function: OpenInboxForServer (in mailWindow.js)
  • Function: selectFolder (in mailWindow.js)
  • Function: openFolderTab (in mailWindowOverlay.js)
  • Function: LoadNavigatedToMessage (in messageWindow.js)
  • Function: LoadNavigatedToMessage (in msgMail3PaneWindow.js)
  • Function: OnLocationTreeSelect (in msgMail3PaneWindow.js)
  • Function: SelectServer (in msgMail3PaneWindow.js)
  • Function: loadStartFolder (in msgMail3PaneWindow.js)
  • Function: RenameFolder (in widgetglue.js)
  • Function: loadInboxForNewAccount (in accountUtils.js)
  • Function: DropOnFolderTree (in messengerdnd.js)
  • Function: CrossFolderNavigation (in msgViewNavigation.js)

The code, as always, is available at http://hg.mozilla.org/users/bugmail_asutherland.org/pecobro/

master control pecobro, the overkill performance code browser

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The title isn’t true yet, but it’s disturbingly almost-true.  Pecobro’s hackish underpinnings have been “accidentally” replaced with surprisingly forward-looking code capable of supporting a much fancier feature set.  (I didn’t mean to, but I got tricked because the incremental cost to doing the ‘right thing’ was always so low.)

The trace that you can see here, by clicking on any of this text what has coloring (and using firefox 3 in a session that you don’t mind if it crashes), is of running Mark Banner (Standard8)‘s Thunderbird bloatTest on OS X with DTrace probes enabled, but without actually doing the bloat testing.  So Thunderbird starts up, opens the address book, closes it, opens the compose window, closes it, and then quits.

Here is a preliminary processed trace from a run triggering bug 296453.  Be forewarned that there is some missing information from the underlying trace and so it’s not all that it could be.  I think the XPConnect probes need to be fleshed out slightly more (and processed).

The code (both pecobro and mozilla codebase patches) is at: http://hg.mozilla.org/users/bugmail_asutherland.org/

What crazy overkill things can pecobro do now?

  • Parse all of the javascript code used in Thunderbird, including nearly all (maybe all?) of the 1.x enhancements.  The parser is still a bit hackish, especially when it comes to support of regexes, but it actually parses things.  Thanks to Chris Lambrou for posting his initial JavaScript.g antlr3 grammar (and BSD licensing it) that I used as a basis for my hacky version.  This was certainly a learning experience; I now know that javascript can never replace python in my heart…
  • Find all of the places functions can be defines in javascript code and do a pretty good job at figuring out reasonable names for them.  This even includes “(new)? Function()”.  This allows us to use the function-info DTrace probes to use line number information to identify functions.  We do this so that we can identify anonymous functions.
  • Handle XBL as well as we handle pure-javascript files.  (Parsing/AST fix-ups/syntax highlighting with AST traversal/etc.)
  • Parse/interpret disturbingly large portions of makefiles.  Sure, it ignores the rules, and I’ve only implemented the functions I require, but it does all the conditional and include stuff with variable expansion, including some key functions like foreach/filter/etc.
  • Parse jar manifests sufficiently well to figure out what file ends up at what chrome path.
  • Cache its javascript parse results at both the AST and (sorta-semantic) processing level, among other things.  Hooray for cerealizer which dares persist/de-persist that which pickle dare not.  (Nested classes.)  (Note: We don’t cache XBL stuff yet, and the ASTs are large enough that de-persisting them can be quite perceptible.)

What is not crazy, but still nice:

  • The traces are now much more reliable thanks to modifications to the Mozilla USDT probes to provide sufficient information for us to distinguish between JavaScript execution contexts (namely, JSContext).  Modifications were also made to avoid the ‘guessing’/ghost value problems that happen when native functions were called.
  • A foolish bug in the sparkbar calculation has been fixed.  aka “Now With Accuracy”!
  • If a function in a trace called another function or was called by another function, this will be displayed inline in the source display.
  • Infer ‘native’ functions (with the above additional modifications to the Mozilla USDT probes), assigning them to an object.  This ends up being Object, ChromeWindow, or other native Class type.  Some of this may be mooted by getting the XPConnect probes reliably in the mix.

What doesn’t it do?

  • Add the XPConnect js_Invoke probes; I punted on that because that was turning out to be difficult to get right.
  • It ignores .xul files for now.  Although xul files primarily appears in a caller context (as told by function-info probes), they can also be a callee when someone pulls a fast one and inlines some simple code in a script tag.  We brutally mis-attribute the call to the previous function when this happens.  This will eventually get resolved because we will need to understand .xul files for namespace reasons.  Also, people sound like they’re interested in who overlays what and the like, and that’s sorta right up our alley thanks to all the overkill stuff we do.
  • Exhaustively determine reads from/contributions to the ‘global’ (window or what not) namespace/scope.  The groundwork is there in terms of understanding the contribution of top-level statements to the namespace or its reads from it, but we don’t traverse into functions.
  • Associate functions with an object/type (ignoring the native function case).  This requires more semantic understanding.
  • Clicking on functions still doesn’t do anything.  I disabled that before my first post on pecobro due to firefox-crashing issues, and still haven’t gotten around to resolving it.
  • A usable overview visualization.  The overview diagram has become cluttered by the presence of so many ‘relevant’ (touched) files.

pecobro: the performance code browser (early stage)

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At the beginning of last week, I had gotten dtrace working on a Mac Mini using the Mozilla javascript-provider probes.  Very cool stuff, but it left me with several questions about what would really be best to do next:

  • How do I best understand what I’m seeing?  (Most of the codebase is brand new to me…)
  • How do I share the data with others in a way that is both comprehensible and allows them to draw their own conclusions from the data?
  • What can I do to reduce the effort required to work on performance problems?

I was tempted to just try and just dig into the system so I could have something to show immediately, but I knew it would still take a while to see the big picture just using an editor/ctags/lxr/opengrok, even informed by dtrace.  And even then, that big picture doesn’t scale well; whatever picture I managed to formulate would be stuck inside my head…

So my solution was to try and build a tool that could help me accomplish my short-term goals soon, and have the potential to grow into a usable solution to all of the above… eventually.  The goal, in a nutshell, is to provide a code browser for javascript that is able to integrate performance information (retrieved from traces) alongside the code.  Seeing that lxr/mxr and opengrok didn’t understand javascript or XBL all that well, it also seemed feasible to try and improve on their browsing capabilities for javascript.  A far-down-the-road goal is also to be able to pull in information from the underlying C++ code as well, potentially leveraging dehydra, etc.  (This would primarily be for understanding what happens when we leave the javascript layer, not trying to be the same solution for C++ space.)

So what can it do so far?  You can go try it for yourself if you like as long as you keep your expectations very low and realize the current state does not reflect all of the bullet points below.  Also, you probably want firefox 3.0.  Or you can read my bullet points:

  • Parse custom DTrace script output!  The Mozilla DTrace probe points could probably use a little love to improve what we are able to get out.  Also, I think it’s betraying us somewhere.
  • Parse JavaScript! Sorta!  (I hacked in support for the regular expression syntax, but I haven’t corrected the ambiguity with division, so things with division break.  Also, there’s at least one or two other glitches that cause early termination.) [Yay antlr!]
  • Parse XBL!  Even with entity inlining!  Even when people put #ifdefs in the XML document! Sorta!  We don’t actually do anything intelligent with the XBL right now or with its JavaScript, but it won’t take much to get that much improved. [Yay elementtree!]
  • Visualize some stuff!  Inter-file relationship graph in the overview.  In the code and ‘Funcs’ sidebar tab you get a sparkbar where each bar represents a time interval.  The height of the par is the percentage of possible time we could have spent in that time interval.  Red means we belive that time was spent in the function itself, green means we think we spent that time in calls to other functions. [Yay visophyte!]
  • Navigate with history!  Click on the overview graph and you go to things.  Click on the file names in the ‘Files’ list and you go to the files.  I tried to make it so you could click on function names in the side bars to go to them, but jquery.scrollTo and/or firefox 3.0b5 had serious crashing issues.  [Yay jquery, jquery.history!]
  • See syntax-highlighted code with random headings intertwined (shows the parser worked) and potentially a visualization.  [Yay pygments!]

My hope in the near-term is to fix the outright bugs (parsing issues), get XBL going, and then augment the function information with more trace-derived data including more traditional call-stacks, etc.  Then the tool should be sufficiently usable that my immediate focus can change to creating automated tests to actually gather performance/execution traces so we can use the tool for what I started it for.  This may also get shelved for a while if it turns out that we need action (patches) immediately.