tree e3f190ebbabe4470d96ce228521a8755b9475de7
parent b1bdeeb0ee670acbcfab089a39db5749d13ff9f1
author Shawn Pearce <spearce@spearce.org> 1500440310 -0700
committer Shawn Pearce <spearce@spearce.org> 1500440310 -0700

dfs: Fix caching of index, bitmap index, reverse index

When 07f98a8b71 ("Derive DfsStreamKey from DfsPackDescription")
stopped caching DfsPackFile in the DfsBlockCache, the DfsPackFile began
to always load the idx, bitmap, or compute reverse index, as the cache
handles were no longer populated by prior requests.

Rework caching to lookup the objects from the DfsBlockCache if the
local DfsPackFile handle is invalid.  This allows the DfsPackFile to
be more of a flyweight instance across requests.

Change-Id: Ic7b42ce2d90692cccea36deb30c2c76ccc81638b