glusterfind: Speed up gfid lookup 100x by using an SQL index

Fixes #1529883.

This fixes some bits of `glusterfind`'s horrible performance,
making it 100x faster.

Until now, glusterfind was, for each line in each CHANGELOG.* file,
linearly reading the entire contents of the sqlite database in
4096-bytes-sized pread64() syscalls when executing the

  SELECT COUNT(1) FROM %s WHERE 1=1 AND gfid = ?

query through the code path:

  get_changes()
    parse_changelog_to_db()
      when_data_meta()
        gfidpath_exists()
          _exists()

In a quick benchmark on my laptop, doing one such `SELECT` query
took ~75ms on a 10MB-sized sqlite DB, while doing the same query
with an index took < 1ms.

Change-Id: I8e7fe60f1f45a06c102f56b54d2ead9e0377794e
BUG: 1529883
Signed-off-by: Niklas Hambüchen <mail@nh2.me>

0 files changed, 0 insertions, 0 deletions