view tests/test-encode.t @ 51108:0250e45040f1

revlog: add a small cache of unfiltered chunk

This can provides a massive boost to the reading of multiple revision and the
computation of a valid delta chain.

This greatly help operation like `hg log --patch`, delta computation (helping
pull/unbundle), linkrev adjustment (helping copy tracing).

A first round of benchmark for `hg log --patch --limit 1000` shows improvement
in the 10-20% range on "small" repository like pypy or mercurial and large
improvements (about 33%) for more complex ones like netbeans and mozilla's.

These speeds up are consistent with the improvement to `hg pull` (from a server
sending poor deltas) I saw benchmarking this last year. Further benchmark will
be run during the freeze.

I added some configuration in the experimental space to be able to further test
the effect of various tuning for now. This feature should fit well in the
"usage/resource profile" configuration that we should land next cycle.

When it does not provides a benefit the overhead of the cache seem to be around
2%, a small price for the big improvement. In addition I believe we could shave
most of this overhead with a more efficent lru implementation.

Test encode/decode filters

  $ hg init repo
  $ cd repo
  $ cat > .hg/hgrc <<EOF
  > [encode]
  > not.gz = tr [:lower:] [:upper:]
  > *.gz = gzip -d
  > [decode]
  > not.gz = tr [:upper:] [:lower:]
  > *.gz = gzip
  > EOF
  $ echo "this is a test" | gzip > a.gz
  $ echo "this is a test" > not.gz
  $ hg add *
  $ hg ci -m "test"

no changes

  $ hg status
  $ touch *

no changes

  $ hg status

check contents in repo are encoded

  $ hg debugdata a.gz 0
  this is a test
  $ hg debugdata not.gz 0
  THIS IS A TEST

check committed content was decoded

  $ gunzip < a.gz
  this is a test
  $ cat not.gz
  this is a test
  $ rm *
  $ hg co -C
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

check decoding of our new working dir copy

  $ gunzip < a.gz
  this is a test
  $ cat not.gz
  this is a test

check hg cat operation

  $ hg cat a.gz
  this is a test
  $ hg cat --decode a.gz | gunzip
  this is a test
  $ mkdir subdir
  $ cd subdir
  $ hg -R .. cat ../a.gz
  this is a test
  $ hg -R .. cat --decode ../a.gz | gunzip
  this is a test
  $ cd ..

check tempfile filter

  $ hg cat a.gz --decode --config 'decode.*.gz=tempfile:gzip -c INFILE > OUTFILE' | gunzip
  this is a test
  $ hg cat a.gz --decode --config 'decode.*.gz=tempfile:sh -c "exit 1"'
  abort: command '*' failed: exited with status 1 (glob)
  [255]

  $ cd ..