Speed up loadPublicResources()

The FrameworkResources method which loads in the public resources
takes about ~500ms of the target loading time.

This changeset optimizes this down to < 50ms using the following
three optimizations:

1) Precompute a map from names to ResourceItems before processing the
   public names. Before this, it would search sequentially through the
   name list, which when done n times meant O(n^2); we can construct
   the map in O(n) and then perform n lookups in O(1) => O(n).

   Also, be smart about which maps we precompute names for: the
   ResourceType.PUBLIC and ResourceType.DECLARE_STYLEABLE types have
   about 2,000 items, none of which are public, so skip precomputing
   maps for these two. (However, keep the linear search around such
   that if any are exported in the future the code will work
   correctly.

   Similarly, we know "roughly" the size of the final public maps, so
   initialize them in the right size range such that they don't have
   to do any internal resize+copy operations as we insert into them.

2) In android-15 there are 1500 new <java-symbol> elements in the
   public xml file, which were being processed, doubling the number of
   exported symbols. Limit the processing to only the <public> tags.

3) Switch from DOM parsing to pull parsing. This helps since more than
   half the file consists of <java-symbol> elements, and we can ignore
   whitespace and id attributes etc, so there is much less object
   creation involved.

Change-Id: I4761e1182b9bc0c50fe94aea7dcd9690754c7908

1 files changed, 2 insertions, 0 deletions

diff --git a/eclipse/dictionary.txt b/eclipse/dictionary.txt
index dca9b23..c1640c0 100644
--- a/eclipse/dictionary.txt
+++ b/eclipse/dictionary.txt
@@ -192,6 +192,8 @@ popup
 popups
 pre
 precompiler
+precompute
+precomputing
 pref
 prefs
 preload