tree fd3c9d54b128363e780f56380f3ce057a45576eb
parent 0137edef8948ad6c3ce722f359dd4b39c93f449d
author Sigmund Cherem <sigmund@google.com> 1541442273 +0000
committer William Hesse <whesse@google.com> 1541568840 +0100

Encode dart2js source-map extensions in strings.

This reduce the memory footprint and cost of parsing these extensions.  Another
advantage is a reduction on the size of the .map files.  On a large customer
app, this was a 11% reduction, and the frames section was about 1Mb (excluding
the extra names and uris added on the existing tables).

The encoding works as follows:
 - minified names are written as a list of names and indices, in pairs.

    {'n1': 1, 'n2': 2} => 'n1,1,n2,2'

 - frames are encoded using a sequence of values with markers for the different
   kind of frames. Numbers are encoded using VLQ deltas. We use VLQ because it's
   already available to any parser that deals with the mappings).

This change also uses the dart2js_tools parser implementation for all unit tests.

Change-Id: Iacc2833c6517eb473955cc618adec501c610870f
Reviewed-on: https://dart-review.googlesource.com/c/82780
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Sigmund Cherem <sigmund@google.com>