tree edb9595e39616597ec4c5255b24539d97b727f3e
parent d7edcc9bc4728c63f04a1a85556c9714c2911b3c
author Tom Cherry <tomcherry@google.com> 1509142682 -0700
committer Tom Cherry <tomcherry@google.com> 1513037502 -0800

Parse property contexts via a serialized trie

Currently, whenever a new program starts, libc initializes two data
structures related to properties from the raw property_context files.
There are two problems here,
1) This takes roughly 1.2ms on a trivial program to generate contents
   that could otherwise be cached.
2) One of the data structures is a descending list of prefixes, each
   of which needs to be checked, whereas a trie would be more
   efficient.

This change introduces two libraries,
1) libpropertycontextserializer meant to be used by property_service
   to create a serialized trie containing all of the property
   contexts.
2) libpropertycontextparser meant to be used by libc's property
   functions to parse this serialized trie during property lookup.

This new trie also contains the ability to have exact matches instead
of prefix matches for properties, which was not possible before.

Bug: 36001741
Change-Id: I42324f04c4d995a0e055e9685d79f40393dfca51