view tests/test-churn.t @ 26457:7e81305092a0

demandimport: replace more references to _demandmod instances

_demandmod instances may be referenced by multiple importing modules.
Before this patch, the _demandmod instance only maintained a reference
to its first consumer when using the "from X import Y" syntax. This is
because we only created a single _demandmod instance (attached to the
parent X module). If multiple modules A and B performed
"from X import Y", we'd produce a single _demandmod instance
"demandmod" with the following references:

  X.Y = <demandmod>
  A.Y = <demandmod>
  B.Y = <demandmod>

The locals from the first consumer (A) would be stored in <demandmod1>.
When <demandmod1> was loaded, we'd look at the locals for the first
consumer and replace the symbol, if necessary. This resulted in state:

  X.Y = <module>
  A.Y = <module>
  B.Y = <demandmod>

B's reference to Y wasn't updated and was still using the proxy object
because we just didn't record that B had a reference to <demandmod> that
needed updating!

With this patch, we add support for tracking which modules in addition
to the initial importer have a reference to the _demandmod instance and
we replace those references at module load time.

In the case of posix.py, this fixes an issue where the "encoding" module
was being proxied, resulting in hundreds of thousands of
__getattribute__ lookups on the _demandmod instance during dirstate
operations on mozilla-central, speeding up execution by many
milliseconds. There are likely several other operation that benefit from
this change as well.

The new mechanism isn't perfect: references in locals (not globals) may
likely linger. So, if there is an import inside a function and a symbol
from that module is used in a hot loop, we could have unwanted overhead
from proxying through _demandmod. Non-global imports are discouraged
anyway. So hopefully this isn't a big deal in practice. We could
potentially deploy a code checker that bans use of attribute lookups of
function-level-imported modules inside loops.

This deficiency in theory could be avoided by storing the set of globals
and locals dicts to update in the _demandmod instance. However, I tried
this and it didn't work. One reason is that some globals are _demandmod
instances. We could work around this, but it's a bit more work. There
also might be other module import foo at play. The solution as
implemented is better than what we had and IMO is good enough for the
time being.

It's worth noting that this sub-optimal behavior was made worse by the
introduction of absolute_import and its recommended "from . import X"
syntax for importing modules from the "mercurial" package. If we ever
wrote performance tests, measuring the amount of module imports and
__getattribute__ proxy calls through _demandmod instances would be
something I'd have it check.

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "churn=" >> $HGRCPATH

create test repository

  $ hg init repo
  $ cd repo
  $ echo a > a
  $ hg ci -Am adda -u user1 -d 6:00
  adding a
  $ echo b >> a
  $ echo b > b
  $ hg ci -m changeba -u user2 -d 9:00 a
  $ hg ci -Am addb -u user2 -d 9:30
  adding b
  $ echo c >> a
  $ echo c >> b
  $ echo c > c
  $ hg ci -m changeca -u user3 -d 12:00 a
  $ hg ci -m changecb -u user3 -d 12:15 b
  $ hg ci -Am addc -u user3 -d 12:30
  adding c
  $ mkdir -p d/e
  $ echo abc > d/e/f1.txt
  $ hg ci -Am "add d/e/f1.txt" -u user1 -d 12:45 d/e/f1.txt
  $ mkdir -p d/g
  $ echo def > d/g/f2.txt
  $ hg ci -Am "add d/g/f2.txt" -u user1 -d 13:00 d/g/f2.txt


churn separate directories

  $ cd d
  $ hg churn e
  user1      1 ***************************************************************

churn all

  $ hg churn
  user1      3 ***************************************************************
  user3      3 ***************************************************************
  user2      2 ******************************************

churn excluding one dir

  $ hg churn -X e
  user3      3 ***************************************************************
  user1      2 ******************************************
  user2      2 ******************************************

churn up to rev 2

  $ hg churn -r :2
  user2      2 ***************************************************************
  user1      1 ********************************
  $ cd ..

churn with aliases

  $ cat > ../aliases <<EOF
  > user1 alias1
  > user3 alias3
  > not-an-alias
  > EOF

churn with .hgchurn

  $ mv ../aliases .hgchurn
  $ hg churn
  skipping malformed alias: not-an-alias
  alias1      3 **************************************************************
  alias3      3 **************************************************************
  user2       2 *****************************************
  $ rm .hgchurn

churn with column specifier

  $ COLUMNS=40 hg churn
  user1      3 ***********************
  user3      3 ***********************
  user2      2 ***************

churn by hour

  $ hg churn -f '%H' -s
  06      1 *****************
  09      2 *********************************
  12      4 ******************************************************************
  13      1 *****************


churn with separated added/removed lines

  $ hg rm d/g/f2.txt
  $ hg ci -Am "removed d/g/f2.txt" -u user1 -d 14:00 d/g/f2.txt
  $ hg churn --diffstat
  user1           +3/-1 +++++++++++++++++++++++++++++++++++++++++--------------
  user3           +3/-0 +++++++++++++++++++++++++++++++++++++++++
  user2           +2/-0 +++++++++++++++++++++++++++

churn --diffstat with color

  $ hg --config extensions.color= churn --config color.mode=ansi \
  >     --diffstat --color=always
  user1           +3/-1 \x1b[0;32m+++++++++++++++++++++++++++++++++++++++++\x1b[0m\x1b[0;31m--------------\x1b[0m (esc)
  user3           +3/-0 \x1b[0;32m+++++++++++++++++++++++++++++++++++++++++\x1b[0m (esc)
  user2           +2/-0 \x1b[0;32m+++++++++++++++++++++++++++\x1b[0m (esc)


changeset number churn

  $ hg churn -c
  user1      4 ***************************************************************
  user3      3 ***********************************************
  user2      2 ********************************

  $ echo 'with space = no-space' >> ../aliases
  $ echo a >> a
  $ hg commit -m a -u 'with space' -d 15:00

churn with space in alias

  $ hg churn --aliases ../aliases -r tip
  no-space      1 ************************************************************

  $ cd ..


Issue833: ZeroDivisionError

  $ hg init issue-833
  $ cd issue-833
  $ touch foo
  $ hg ci -Am foo
  adding foo

this was failing with a ZeroDivisionError

  $ hg churn
  test      0 
  $ cd ..

Ignore trailing or leading spaces in emails

  $ cd repo
  $ touch bar
  $ hg ci -Am'bar' -u 'user4 <[e-mail]>'
  adding bar
  $ touch foo
  $ hg ci -Am'foo' -u 'user4 < [e-mail] >'
  adding foo
  $ hg log -l2 --template '[{author|email}]\n'
  [ [e-mail] ]
  [[e-mail]]
  $ hg churn -c
  user1            4 *********************************************************
  user3            3 *******************************************
  user2            2 *****************************
  [e-mail]      2 *****************************
  with space       1 **************

Test multibyte sequences in names

  $ echo bar >> bar
  $ hg --encoding utf-8 ci -m'changed bar' -u 'El Niño <[e-mail]>'
  $ hg --encoding utf-8 churn -ct '{author|person}'
  user1           4 **********************************************************
  user3           3 ********************************************
  user2           2 *****************************
  user4           2 *****************************
  El Ni\xc3\xb1o         1 *************** (esc)
  with space      1 ***************

Test --template argument, with backwards compatiblity

  $ hg churn -t '{author|user}'
  user1      4 ***************************************************************
  user3      3 ***********************************************
  user2      2 ********************************
  nino       1 ****************
  with       1 ****************
             0 
  user4      0 
  $ hg churn -T '{author|user}'
  user1      4 ***************************************************************
  user3      3 ***********************************************
  user2      2 ********************************
  nino       1 ****************
  with       1 ****************
             0 
  user4      0 
  $ hg churn -t 'alltogether'
  alltogether     11 *********************************************************
  $ hg churn -T 'alltogether'
  alltogether     11 *********************************************************

  $ cd ..