See the comments for an explanation of how properties are stored.
The trie structure is designed to scale better than the previous
array-based implementation. Searching an array with n properties
required average O(n) string compares of the entire key; searching the
trie requires average O(log n) string compares of each token (substrings
between '.' characters).
Signed-off-by: Greg Hackmann <ghackmann@google.com>
(cherry picked from commit 6ac8e6a46d71a51bec16938efa89f275fa89cf7d)
Change-Id: Icbe31908572f33b4d9b85d5b62ac837cbd0f85e0
996cdc4b1a