view tests/test-addremove.t @ 34880:9e18ab7f7240

sparse-read: move from a recursive-based approach to a heap-based one

The previous recursive approach was trying to optimise each read slice to have
a good density. It had the tendency to over-optimize smaller slices while
leaving larger hole in others.

The new approach focuses on improving the combined density of all the reads,
instead of the individual slices. It slices at the largest gaps first, as they
reduce the total amount of read data the most efficiently.

Another benefit of this approach is that we iterate over the delta chain only
once, reducing the overhead of slicing long delta chains.

On the repository we use for tests, the new approach shows similar or faster
performance than the current default linear full read.

The repository contains about 450,000 revisions with many concurrent
topological branches. Tests have been run on two versions of the repository:
one built with the current delta constraint, and the other with an unlimited
delta span (using 'experimental.maxdeltachainspan=0')

Below are timings for building 1% of all the revision in the manifest log using
'hg perfrevlogrevisions -m'. Times are given in seconds. They include the new
couple of follow-up changeset in this series.

delta-span  standard    unlimited
linear-read     922s         632s
sparse-read     814s         566s

  $ hg init rep
  $ cd rep
  $ mkdir dir
  $ touch foo dir/bar
  $ hg -v addremove
  adding dir/bar
  adding foo
  $ hg -v commit -m "add 1"
  committing files:
  dir/bar
  foo
  committing manifest
  committing changelog
  committed changeset 0:6f7f953567a2
  $ cd dir/
  $ touch ../foo_2 bar_2
  $ hg -v addremove
  adding dir/bar_2
  adding foo_2
  $ hg -v commit -m "add 2"
  committing files:
  dir/bar_2
  foo_2
  committing manifest
  committing changelog
  committed changeset 1:e65414bf35c5
  $ cd ..
  $ hg forget foo
  $ hg -v addremove
  adding foo
  $ hg forget foo

  $ hg -v addremove nonexistent
  nonexistent: The system cannot find the file specified (windows !)
  nonexistent: No such file or directory (no-windows !)
  [1]

  $ cd ..

  $ hg init subdir
  $ cd subdir
  $ mkdir dir
  $ cd dir
  $ touch a.py
  $ hg addremove 'glob:*.py'
  adding a.py
  $ hg forget a.py
  $ hg addremove -I 'glob:*.py'
  adding a.py
  $ hg forget a.py
  $ hg addremove
  adding dir/a.py
  $ cd ..

  $ hg init sim
  $ cd sim
  $ echo a > a
  $ echo a >> a
  $ echo a >> a
  $ echo c > c
  $ hg commit -Ama
  adding a
  adding c
  $ mv a b
  $ rm c
  $ echo d > d
  $ hg addremove -n -s 50 # issue 1696
  removing a
  adding b
  removing c
  adding d
  recording removal of a as rename to b (100% similar)
  $ hg addremove -s 50
  removing a
  adding b
  removing c
  adding d
  recording removal of a as rename to b (100% similar)
  $ hg commit -mb
  $ cp b c
  $ hg forget b
  $ hg addremove -s 50
  adding b
  adding c

  $ rm c

  $ hg ci -A -m "c" nonexistent
  nonexistent: The system cannot find the file specified (windows !)
  nonexistent: No such file or directory (no-windows !)
  abort: failed to mark all new/missing files as added/removed
  [255]

  $ hg st
  ! c
  $ cd ..