view tests/test-commit-copy.t @ 16363:2cdd7e63211b

parsers: incrementally parse the revlog index in C

We only parse entries in a revlog index file when they are actually
needed, and cache them when first requested.

This makes a huge difference to performance on large revlogs when
accessing the tip revision or performing a handful of numeric lookups
(very common cases).  For instance, "hg --time tip --template {node}"
on a tree with 300,000 revs takes 0.15 before, 0.02 after.

Even for revlog-intensive operations (e.g. running "hg log" to
completion), the lazy approach is about 1% faster than the eager
parse_index2.

  $ hg init dir
  $ cd dir
  $ echo bleh > bar
  $ hg add bar
  $ hg ci -m 'add bar'

  $ hg cp bar foo
  $ echo >> bar
  $ hg ci -m 'cp bar foo; change bar'

  $ hg debugrename foo
  foo renamed from bar:26d3ca0dfd18e44d796b564e38dd173c9668d3a9
  $ hg debugindex bar
     rev    offset  length   base linkrev nodeid       p1           p2
       0         0       6      0       0 26d3ca0dfd18 000000000000 000000000000
       1         6       7      1       1 d267bddd54f7 26d3ca0dfd18 000000000000