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Author SHA1 Message Date
Gabriel Wicke d918fa18ac Big token transform framework overhaul part 2
* Tokens are now immutable. The progress of transformations is tracked on
  chunks instead of tokens. Tokenizer output is cached and can be directly
  returned without a need for cloning. Transforms are required to clone or
  newly create tokens they are modifying.

* Expansions per chunk are now shared between equivalent frames via a cache
  stored on the chunk itself. Equivalence of frames is not yet ideal though,
  as right now a hash tree of *unexpanded* arguments is used. This should be
  switched to a hash of the fully expanded local parameters instead.

* There is now a vastly improved maybeSyncReturn wrapper for async transforms
  that either forwards processing to the iterative transformTokens if the
  current transform is still ongoing, or manages a recursive transformation if
  needed.

* Parameters for parser functions are now wrapped in abstract Params and
  ParserValue objects, which support some handy on-demand *value* expansions.
  Keys are always expanded. Parser functions are converted to use these
  interfaces, and now properly expand their values in the correct frame.
  Making this expansion lazier is certainly possible, but would complicate
  transformTokens and other token-handling machinery. Need to investigate if
  it would really be worth it. Dead branch elimination is certainly a bigger
  win overall.

* Complex recursive asynchronous expansions should now be closer to correct
  for both the iterative (transformTokens) and recursive (maybeSyncReturn
  after transformTokens has returned) code paths.

* Performance degraded slightly. There are no micro-optimizations done yet
  and the shared expansion cache still has a low hit rate. The progress
  tracking on chunks is not yet perfect, so there are likely a lot of unneeded
  re-expansions that can be easily eliminated. There is also more debug
  tracing right now. Obama currently expands in 54 seconds on my laptop.

Change-Id: I4a603f3d3c70ca657ebda9fbb8570269f943d6b6
2012-05-15 17:05:47 +02:00
Gabriel Wicke 8368e17d6a Biggish token transform system refactoring
* All parser pipelines including tokenizer and DOM stuff are now constructed
  from a 'recipe' data structure in a ParserPipelineFactory.

* All sub-pipelines of these can now be cached

* Event registrations to a pipeline are directly forwarded to the last
  pipeline member to save relatively expensive event forwarding.

* Some APIs for on-demand expansion / format conversion of parameters from
  parser functions are added:

  param.to('tokens/expanded', cb)
  param.to('text/wiki', cb) (this does not work yet)

  All parameters are additionally wrapped into a Param object that provides
  method for positional parameter naming (.named() or conversion to a dict
  (.dict()).

* The async token transform manager is now separated from a frame object, with
  the frame holding arguments, an on-demand expansion method and loop checks.

* Only keys of template parameters are now expanded. Parser functions or
  template arguments trigger an expansion on-demand. This (unsurprisingly)
  makes a big performance difference with typical switch-heavy template
  systems.

* Return values from async transforms are no longer used in favor of plain
  callbacks. This saves the complication of having to maintain two code paths.
  A trick in transformTokens still avoids the construction of unneeded
  TokenAccumulators.

* The results of template expansions are no longer buffered.

* 301 parser tests are passing

Known issues:

* Cosmetic cleanup remains to do
* Some parser functions do not support async expansions yet, and need to be
  modified.

Change-Id: I1a7690baffbe8141cadf67270904a1b2e1df879a
2012-04-25 16:51:36 +02:00
Gabriel Wicke e2ca8c24c7 Delay some token duplication until actual mutation happens
This is a bit better than cloning tokens wholesale, but not by much. There is
a lot of potential for much better per-token caching with reduced token
cloning. Need to map out all dependencies besides token attributes expanded
from template parameters or other scoped state. Even if tokens themselves
don't need transformation, they might still need to be considered for other
token transformers, so simply keeping the final rank won't quite work even if
the token itself is fully transformed. As a minimum, a shallow clone would
need to be made and the rank reset (as in env.cloneTokens).

Change-Id: I4329113bb21750bae9a635229ed1b08da75dc614
2012-04-18 17:53:04 +02:00
Gabriel Wicke 5bb2d96869 Token stream transform improvements
* add past paths for empty arguments etc
* cache attribute token transform pipelines
* fix bugs in TokenCollector and NoIncludeOnly handler, and improve its
  efficiency by only registering for 'end' tokens on demand
* Remove empty reset methods from a few handlers
* Add a simple 'ap' debug print function that makes it easy to only print some
  debug prints by temporarily changing 'dp' to 'ap'
* Improvements and bug fixes in AttributeExpander

Change-Id: Ie69729c8f62d48bba922712e44ebce484c621c50
2012-04-12 15:42:09 +02:00
Gabriel Wicke af03eb4f29 Improve generic attribute expansion before external link processing, and make
wgUploadPath configurable. Also change the hard-coded fall-back image sizes to
sensible defaults. This breaks three parser tests until image size retrieval
from the wiki is implemented.
2012-03-06 18:02:35 +00:00
Gabriel Wicke 4b9bd45b82 Start to move wikilink expansion to a separate async token transformer. 2012-02-29 13:56:29 +00:00
Gabriel Wicke 8dde1f77b4 Reduce debug print overhead, roughly a 10% speed-up on parserTests. 2012-02-21 18:49:43 +00:00
Gabriel Wicke aff30be131 Some comments and reshuffling in the grammar, and a typo in the
AttributeExpander.
2012-02-09 22:27:45 +00:00
Gabriel Wicke 6e33255503 Improve support for preprocessor functionality in attributes; Support
multi-line xmlish tags with preprocessor stuff in attributes.
2012-02-09 16:36:29 +00:00
Gabriel Wicke 6983481561 Move attribute expansion back to separate handler, as this makes it easier to
only expand used branches selected by parser functions. Template (and
-argument) expansion is simply registered before general expansion.

Additionally, a few more simple time-based magic words are added in
ParserFunctions.
2012-02-09 13:44:20 +00:00