tree c6e606bee360a54b32a9c0ec070a9ad4759edacf
parent 454f5067d1c75b75363587e6e95d68c5b82d6daf
author Dave Borowitz <dborowitz@google.com> 1402448589 -0700
committer Dave Borowitz <dborowitz@google.com> 1403649512 +0000

Extract findLastCommit method from BlameServlet into BlameCache

On a slow DFS backend like the one used by googlesource.com, walking
commits may be much slower than on a local disk with a hot buffer
cache, and this step may require walking hundreds of thousands of
commits.

Optimizing this operation in the most common case is not likely to be
useful, so the default implementation does no caching. However,
extracting this into the BlameCache interface allows for more complex
implementations in alternate backends.

Change-Id: Id138dbae9fb8ecb82a6b6e486d5d162869cc04ed