elasticsearch/elasticsearch — pull request #5489 by kimchy (2014-03-21 21:54:47+00:00)
Title: Freq Terms Enum

A frequency caching terms enum, that also allows to be configured with an optional filter. To be used by both significant terms and phrase suggester.
This change extracts the frequency caching into the same code, and allow in the future to add a filter to control/customize the background frequencies