localrepo: also fastpath access to working copy parents when possible If the filter level guarantee that the working copy parents will be visible, we allow fast path access to them. With this change multiple commands can now run without triggering filtering. After using the quick access mechanism introduced, the whole series results in pretty good performance gain: ``` All benchmarks: before after ratio [8e095512] [36b2f659] - 711±0.8ms 60.7±0.2ms 0.09 simple_command.read.diff.empty.time_bench('mercurial-filtered-2019-11-22', 'zstd', 'default', True, True, True, True, True, 1) [citrea/virtualenv-py2.7-pyyaml-HGMODULEPOLICYc-HGWITHRUSTEXTcpython] - 712±0.8ms 61.6±0.2ms 0.09 simple_command.read.diff.empty.time_bench('mercurial-filtered-2019-11-22', 'zstd', 'default', True, True, True, True, True, 1) [citrea/virtualenv-py2.7-pyyaml-HGMODULEPOLICYrust+c-HGWITHRUSTEXTcpython] - 690±1ms 93.5±0.3ms 0.14 simple_command.read.diff.empty.time_bench('mercurial-filtered-2019-11-22', 'zstd', 'default', True, True, True, True, True, 1) [citrea/virtualenv-py3.7-pyyaml-HGMODULEPOLICYc-HGWITHRUSTEXTcpython] - 688±1ms 93.8±0.3ms 0.14 simple_command.read.diff.empty.time_bench('mercurial-filtered-2019-11-22', 'zstd', 'default', True, True, True, True, True, 1) [citrea/virtualenv-py3.7-pyyaml-HGMODULEPOLICYrust+c-HGWITHRUSTEXTcpython] - 714±1ms 60.7±0.8ms 0.09 simple_command.read.diff.empty.time_bench('mercurial-filtered-2019-11-22', 'zstd', 'default', True, True, True, True, True, 2) [citrea/virtualenv-py2.7-pyyaml-HGMODULEPOLICYc-HGWITHRUSTEXTcpython] - 713±1ms 60.9±0.3ms 0.09 simple_command.read.diff.empty.time_bench('mercurial-filtered-2019-11-22', 'zstd', 'default', True, True, True, True, True, 2) [citrea/virtualenv-py2.7-pyyaml-HGMODULEPOLICYrust+c-HGWITHRUSTEXTcpython] - 689±1ms 93.7±0.2ms 0.14 simple_command.read.diff.empty.time_bench('mercurial-filtered-2019-11-22', 'zstd', 'default', True, True, True, True, True, 2) [citrea/virtualenv-py3.7-pyyaml-HGMODULEPOLICYc-HGWITHRUSTEXTcpython] - 687±2ms 92.8±0.2ms 0.14 simple_command.read.diff.empty.time_bench('mercurial-filtered-2019-11-22', 'zstd', 'default', True, True, True, True, True, 2) [citrea/virtualenv-py3.7-pyyaml-HGMODULEPOLICYrust+c-HGWITHRUSTEXTcpython] - 799±2ms 98.1±0.6ms 0.12 simple_command.read.export.bare.time_bench('mercurial-filtered-2019-11-22', 'zstd', 'default', True, True, True, True, True) [citrea/virtualenv-py2.7-pyyaml-HGMODULEPOLICYc-HGWITHRUSTEXTcpython] - 800±0.8ms 100.0±0.4ms 0.12 simple_command.read.export.bare.time_bench('mercurial-filtered-2019-11-22', 'zstd', 'default', True, True, True, True, True) [citrea/virtualenv-py2.7-pyyaml-HGMODULEPOLICYrust+c-HGWITHRUSTEXTcpython] - 711±0.9ms 111±0.2ms 0.16 simple_command.read.export.bare.time_bench('mercurial-filtered-2019-11-22', 'zstd', 'default', True, True, True, True, True) [citrea/virtualenv-py3.7-pyyaml-HGMODULEPOLICYc-HGWITHRUSTEXTcpython] - 711±1ms 112±0.3ms 0.16 simple_command.read.export.bare.time_bench('mercurial-filtered-2019-11-22', 'zstd', 'default', True, True, True, True, True) [citrea/virtualenv-py3.7-pyyaml-HGMODULEPOLICYrust+c-HGWITHRUSTEXTcpython] - 760±1ms 59.8±0.1ms 0.08 simple_command.read.status.wc_clean.default.time_bench('mercurial-filtered-2019-11-22', 'zstd', 'default', True, True, True, True, True, 1) [citrea/virtualenv-py2.7-pyyaml-HGMODULEPOLICYc-HGWITHRUSTEXTcpython] - 763±2ms 62.2±0.3ms 0.08 simple_command.read.status.wc_clean.default.time_bench('mercurial-filtered-2019-11-22', 'zstd', 'default', True, True, True, True, True, 1) [citrea/virtualenv-py2.7-pyyaml-HGMODULEPOLICYrust+c-HGWITHRUSTEXTcpython] - 689±1ms 93.1±0.3ms 0.14 simple_command.read.status.wc_clean.default.time_bench('mercurial-filtered-2019-11-22', 'zstd', 'default', True, True, True, True, True, 1) [citrea/virtualenv-py3.7-pyyaml-HGMODULEPOLICYc-HGWITHRUSTEXTcpython] - 688±1ms 94.3±0.3ms 0.14 simple_command.read.status.wc_clean.default.time_bench('mercurial-filtered-2019-11-22', 'zstd', 'default', True, True, True, True, True, 1) [citrea/virtualenv-py3.7-pyyaml-HGMODULEPOLICYrust+c-HGWITHRUSTEXTcpython] - 763±1ms 60.1±0.2ms 0.08 simple_command.read.status.wc_clean.default.time_bench('mercurial-filtered-2019-11-22', 'zstd', 'default', True, True, True, True, True, 2) [citrea/virtualenv-py2.7-pyyaml-HGMODULEPOLICYc-HGWITHRUSTEXTcpython] - 763±1ms 62.1±0.4ms 0.08 simple_command.read.status.wc_clean.default.time_bench('mercurial-filtered-2019-11-22', 'zstd', 'default', True, True, True, True, True, 2) [citrea/virtualenv-py2.7-pyyaml-HGMODULEPOLICYrust+c-HGWITHRUSTEXTcpython] - 689±0.8ms 93.2±0.2ms 0.14 simple_command.read.status.wc_clean.default.time_bench('mercurial-filtered-2019-11-22', 'zstd', 'default', True, True, True, True, True, 2) [citrea/virtualenv-py3.7-pyyaml-HGMODULEPOLICYc-HGWITHRUSTEXTcpython] - 687±0.9ms 94.1±0.3ms 0.14 simple_command.read.status.wc_clean.default.time_bench('mercurial-filtered-2019-11-22', 'zstd', 'default', True, True, True, True, True, 2) [citrea/virtualenv-py3.7-pyyaml-HGMODULEPOLICYrust+c-HGWITHRUSTEXTcpython] ``` Differential Revision: https://phab.mercurial-scm.org/D7492

===================================
Test repository filtering avoidance
===================================

This test file is a bit special as he does not check feature, but performance related internal code path.

Right now, filtering a repository comes with a cost that might be significant.
Until this get better, ther are various operation that try hard not to trigger
a filtering computation. This test file make sure we don't reintroduce code that trigger the filtering for these operation:

Setup
-----
  $ hg init test-repo
  $ cd test-repo
  $ echo "some line" > z
  $ echo a > a
  $ hg commit -Am a
  adding a
  adding z
  $ echo "in a" >> z
  $ echo b > b
  $ hg commit -Am b
  adding b
  $ echo "file" >> z
  $ echo c > c
  $ hg commit -Am c
  adding c
  $ hg rm a
  $ echo c1 > c
  $ hg add c
  c already tracked!
  $ echo d > d
  $ hg add d
  $ rm b

  $ cat << EOF >> $HGRCPATH
  > [devel]
  > debug.repo-filters = yes
  > [ui]
  > debug = yes
  > EOF


tests
-----

Getting the node of `null`

  $ hg log -r null -T "{node}\n"
  0000000000000000000000000000000000000000

Getting basic changeset inforation about `null`

  $ hg log -r null -T "{node}\n{date}\n"
  0000000000000000000000000000000000000000
  0.00

Getting status of null

  $ hg status --change null

Getting status of working copy

  $ hg status
  M c
  A d
  R a
  ! b

Getting data about the working copy parent

  $ hg log -r '.' -T "{node}\n{date}\n"
  debug.filters: computing revision filter for "visible"
  c2932ca7786be30b67154d541a8764fae5532261
  0.00

Getting working copy diff

  $ hg diff
  diff -r c2932ca7786be30b67154d541a8764fae5532261 a
  --- a/a	Thu Jan 01 00:00:00 1970 +0000
  +++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,1 +0,0 @@
  -a
  diff -r c2932ca7786be30b67154d541a8764fae5532261 c
  --- a/c	Thu Jan 01 00:00:00 1970 +0000
  +++ b/c	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,1 +1,1 @@
  -c
  +c1
  diff -r c2932ca7786be30b67154d541a8764fae5532261 d
  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
  +++ b/d	Thu Jan 01 00:00:00 1970 +0000
  @@ -0,0 +1,1 @@
  +d
  $ hg diff --change .
  debug.filters: computing revision filter for "visible"
  diff -r 05293e5dd8d1ae4f84a8520a11c6f97cad26deca -r c2932ca7786be30b67154d541a8764fae5532261 c
  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
  +++ b/c	Thu Jan 01 00:00:00 1970 +0000
  @@ -0,0 +1,1 @@
  +c
  diff -r 05293e5dd8d1ae4f84a8520a11c6f97cad26deca -r c2932ca7786be30b67154d541a8764fae5532261 z
  --- a/z	Thu Jan 01 00:00:00 1970 +0000
  +++ b/z	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,2 +1,3 @@
   some line
   in a
  +file

exporting the current changeset

  $ hg export
  debug.filters: computing revision filter for "visible"
  exporting patch:
  # HG changeset patch
  # User test
  # Date 0 0
  #      Thu Jan 01 00:00:00 1970 +0000
  # Node ID c2932ca7786be30b67154d541a8764fae5532261
  # Parent  05293e5dd8d1ae4f84a8520a11c6f97cad26deca
  c
  
  diff -r 05293e5dd8d1ae4f84a8520a11c6f97cad26deca -r c2932ca7786be30b67154d541a8764fae5532261 c
  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
  +++ b/c	Thu Jan 01 00:00:00 1970 +0000
  @@ -0,0 +1,1 @@
  +c
  diff -r 05293e5dd8d1ae4f84a8520a11c6f97cad26deca -r c2932ca7786be30b67154d541a8764fae5532261 z
  --- a/z	Thu Jan 01 00:00:00 1970 +0000
  +++ b/z	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,2 +1,3 @@
   some line
   in a
  +file

using annotate

- file with a single change

  $ hg annotate a
  debug.filters: computing revision filter for "visible"
  0: a

- file with multiple change

  $ hg annotate z
  debug.filters: computing revision filter for "visible"
  0: some line
  1: in a
  2: file