tests/test-convert-cvs.t

revlog: use existing file handle when reading during _addrevision

_addrevision() may need to read from revlogs as part of computing
deltas. Previously, we would flush existing file handles and open
a new, short-lived file handle to perform the reading.

If we have an existing file handle, it seems logical to reuse it
for reading instead of opening a new file handle. This patch
makes that the new behavior.

After this patch, revlog files are only reopened when adding
revisions if the revlog is switched from inline to non-inline.

On Linux when unbundling a bundle of the mozilla-central repo, this
patch has the following impact on system call counts:

Call     Before     After       Delta
write    827,639    673,390   -154,249
open     700,103    684,089    -16,014
read      74,489     74,489          0
fstat    493,924    461,896    -32,028
close    249,131    233,117    -16,014
stat     242,001    242,001          0
lstat     18,676     18,676          0
lseek     20,268     20,268          0
ioctl     14,652     13,173     -1,479
TOTAL  3,180,758  2,930,679   -250,079

It's worth noting that many of the open() calls fail due to missing
files. That's why there are many more open() calls than close().

Despite the significant system call reduction, this change does not
seem to have a significant performance impact on Linux.

On Windows 10 (not a VM, on a SSD), this patch appears to reduce
unbundle time for mozilla-central from ~960s to ~920s. This isn't
as significant as I was hoping. But a decrease it is nonetheless.
Still, Windows unbundle performance is still >2x slower than Linux.

Despite the lack of significant gains, fewer system calls is fewer
system calls. If nothing else, this will narrow the focus of potential
areas to optimize in the future.

#require cvs

  $ cvscall()
  > {
  >     cvs -f "$@"
  > }
  $ hgcat()
  > {
  >     hg --cwd src-hg cat -r tip "$1"
  > }
  $ echo "[extensions]" >> $HGRCPATH
  $ echo "convert = " >> $HGRCPATH
  $ cat > cvshooks.py <<EOF
  > def cvslog(ui,repo,hooktype,log):
  >     print "%s hook: %d entries"%(hooktype,len(log))
  > 
  > def cvschangesets(ui,repo,hooktype,changesets):
  >     print "%s hook: %d changesets"%(hooktype,len(changesets))
  > EOF
  $ hookpath=`pwd`
  $ cat <<EOF >> $HGRCPATH
  > [hooks]
  > cvslog = python:$hookpath/cvshooks.py:cvslog
  > cvschangesets = python:$hookpath/cvshooks.py:cvschangesets
  > EOF

create cvs repository

  $ mkdir cvsrepo
  $ cd cvsrepo
  $ CVSROOT=`pwd`
  $ export CVSROOT
  $ CVS_OPTIONS=-f
  $ export CVS_OPTIONS
  $ cd ..
  $ rmdir cvsrepo
  $ cvscall -q -d "$CVSROOT" init

create source directory

  $ mkdir src-temp
  $ cd src-temp
  $ echo a > a
  $ mkdir b
  $ cd b
  $ echo c > c
  $ cd ..

import source directory

  $ cvscall -q import -m import src INITIAL start
  N src/a
  N src/b/c
  
  No conflicts created by this import
  
  $ cd ..

checkout source directory

  $ cvscall -q checkout src
  U src/a
  U src/b/c

commit a new revision changing b/c

  $ cd src
  $ sleep 1
  $ echo c >> b/c
  $ cvscall -q commit -mci0 . | grep '<--'
  $TESTTMP/cvsrepo/src/b/c,v  <--  *c (glob)
  $ cd ..

convert fresh repo and also check localtimezone option

NOTE: This doesn't check all time zones -- it merely determines that
the configuration option is taking effect.

An arbitrary (U.S.) time zone is used here.  TZ=US/Hawaii is selected
since it does not use DST (unlike other U.S. time zones) and is always
a fixed difference from UTC.

  $ TZ=US/Hawaii hg convert --config convert.localtimezone=True src src-hg
  initializing destination src-hg repository
  connecting to $TESTTMP/cvsrepo
  scanning source...
  collecting CVS rlog
  5 log entries
  cvslog hook: 5 entries
  creating changesets
  3 changeset entries
  cvschangesets hook: 3 changesets
  sorting...
  converting...
  2 Initial revision
  1 ci0
  0 import
  updating tags
  $ hgcat a
  a
  $ hgcat b/c
  c
  c

convert fresh repo with --filemap

  $ echo include b/c > filemap
  $ hg convert --filemap filemap src src-filemap
  initializing destination src-filemap repository
  connecting to $TESTTMP/cvsrepo
  scanning source...
  collecting CVS rlog
  5 log entries
  cvslog hook: 5 entries
  creating changesets
  3 changeset entries
  cvschangesets hook: 3 changesets
  sorting...
  converting...
  2 Initial revision
  1 ci0
  0 import
  filtering out empty revision
  repository tip rolled back to revision 1 (undo convert)
  updating tags
  $ hgcat b/c
  c
  c
  $ hg -R src-filemap log --template '{rev} {desc} files: {files}\n'
  2 update tags files: .hgtags
  1 ci0 files: b/c
  0 Initial revision files: b/c

convert full repository (issue1649)

  $ cvscall -q -d "$CVSROOT" checkout -d srcfull "." | grep -v CVSROOT
  U srcfull/src/a
  U srcfull/src/b/c
  $ ls srcfull
  CVS
  CVSROOT
  src
  $ hg convert srcfull srcfull-hg \
  >     | grep -v 'log entries' | grep -v 'hook:' \
  >     | grep -v '^[0-3] .*' # filter instable changeset order
  initializing destination srcfull-hg repository
  connecting to $TESTTMP/cvsrepo
  scanning source...
  collecting CVS rlog
  creating changesets
  4 changeset entries
  sorting...
  converting...
  updating tags
  $ hg cat -r tip --cwd srcfull-hg src/a
  a
  $ hg cat -r tip --cwd srcfull-hg src/b/c
  c
  c

commit new file revisions

  $ cd src
  $ echo a >> a
  $ echo c >> b/c
  $ cvscall -q commit -mci1 . | grep '<--'
  $TESTTMP/cvsrepo/src/a,v  <--  a
  $TESTTMP/cvsrepo/src/b/c,v  <--  *c (glob)
  $ cd ..

convert again

  $ TZ=US/Hawaii hg convert --config convert.localtimezone=True src src-hg
  connecting to $TESTTMP/cvsrepo
  scanning source...
  collecting CVS rlog
  7 log entries
  cvslog hook: 7 entries
  creating changesets
  4 changeset entries
  cvschangesets hook: 4 changesets
  sorting...
  converting...
  0 ci1
  $ hgcat a
  a
  a
  $ hgcat b/c
  c
  c
  c

convert again with --filemap

  $ hg convert --filemap filemap src src-filemap
  connecting to $TESTTMP/cvsrepo
  scanning source...
  collecting CVS rlog
  7 log entries
  cvslog hook: 7 entries
  creating changesets
  4 changeset entries
  cvschangesets hook: 4 changesets
  sorting...
  converting...
  0 ci1
  $ hgcat b/c
  c
  c
  c
  $ hg -R src-filemap log --template '{rev} {desc} files: {files}\n'
  3 ci1 files: b/c
  2 update tags files: .hgtags
  1 ci0 files: b/c
  0 Initial revision files: b/c

commit branch

  $ cd src
  $ cvs -q update -r1.1 b/c
  U b/c
  $ cvs -q tag -b branch
  T a
  T b/c
  $ cvs -q update -r branch > /dev/null
  $ echo d >> b/c
  $ cvs -q commit -mci2 . | grep '<--'
  $TESTTMP/cvsrepo/src/b/c,v  <--  *c (glob)
  $ cd ..

convert again

  $ TZ=US/Hawaii hg convert --config convert.localtimezone=True src src-hg
  connecting to $TESTTMP/cvsrepo
  scanning source...
  collecting CVS rlog
  8 log entries
  cvslog hook: 8 entries
  creating changesets
  5 changeset entries
  cvschangesets hook: 5 changesets
  sorting...
  converting...
  0 ci2
  $ hgcat b/c
  c
  d

convert again with --filemap

  $ TZ=US/Hawaii hg convert --config convert.localtimezone=True --filemap filemap src src-filemap
  connecting to $TESTTMP/cvsrepo
  scanning source...
  collecting CVS rlog
  8 log entries
  cvslog hook: 8 entries
  creating changesets
  5 changeset entries
  cvschangesets hook: 5 changesets
  sorting...
  converting...
  0 ci2
  $ hgcat b/c
  c
  d
  $ hg -R src-filemap log --template '{rev} {desc} files: {files}\n'
  4 ci2 files: b/c
  3 ci1 files: b/c
  2 update tags files: .hgtags
  1 ci0 files: b/c
  0 Initial revision files: b/c

commit a new revision with funny log message

  $ cd src
  $ sleep 1
  $ echo e >> a
  $ cvscall -q commit -m'funny
  > ----------------------------
  > log message' . | grep '<--' |\
  >  sed -e 's:.*src/\(.*\),v.*:checking in src/\1,v:g'
  checking in src/a,v

commit new file revisions with some fuzz

  $ sleep 1
  $ echo f >> a
  $ cvscall -q commit -mfuzzy . | grep '<--'
  $TESTTMP/cvsrepo/src/a,v  <--  a
  $ sleep 4 # the two changes will be split if fuzz < 4
  $ echo g >> b/c
  $ cvscall -q commit -mfuzzy . | grep '<--'
  $TESTTMP/cvsrepo/src/b/c,v  <--  *c (glob)
  $ cd ..

convert again

  $ TZ=US/Hawaii hg convert --config convert.cvsps.fuzz=2 --config convert.localtimezone=True src src-hg
  connecting to $TESTTMP/cvsrepo
  scanning source...
  collecting CVS rlog
  11 log entries
  cvslog hook: 11 entries
  creating changesets
  8 changeset entries
  cvschangesets hook: 8 changesets
  sorting...
  converting...
  2 funny
  1 fuzzy
  0 fuzzy
  $ hg -R src-hg log -G --template '{rev} ({branches}) {desc} date: {date|date} files: {files}\n'
  o  8 (branch) fuzzy date: * -1000 files: b/c (glob)
  |
  o  7 (branch) fuzzy date: * -1000 files: a (glob)
  |
  o  6 (branch) funny
  |  ----------------------------
  |  log message date: * -1000 files: a (glob)
  o  5 (branch) ci2 date: * -1000 files: b/c (glob)
  
  o  4 () ci1 date: * -1000 files: a b/c (glob)
  |
  o  3 () update tags date: * +0000 files: .hgtags (glob)
  |
  | o  2 (INITIAL) import date: * -1000 files: (glob)
  | |
  o |  1 () ci0 date: * -1000 files: b/c (glob)
  |/
  o  0 () Initial revision date: * -1000 files: a b/c (glob)
  

testing debugcvsps

  $ cd src
  $ hg debugcvsps --fuzz=2
  collecting CVS rlog
  11 log entries
  cvslog hook: 11 entries
  creating changesets
  10 changeset entries
  cvschangesets hook: 10 changesets
  ---------------------
  PatchSet 1 
  Date: * (glob)
  Author: * (glob)
  Branch: HEAD
  Tag: (none) 
  Branchpoints: INITIAL 
  Log:
  Initial revision
  
  Members: 
  	a:INITIAL->1.1 
  
  ---------------------
  PatchSet 2 
  Date: * (glob)
  Author: * (glob)
  Branch: HEAD
  Tag: (none) 
  Branchpoints: INITIAL, branch 
  Log:
  Initial revision
  
  Members: 
  	b/c:INITIAL->1.1 
  
  ---------------------
  PatchSet 3 
  Date: * (glob)
  Author: * (glob)
  Branch: INITIAL
  Tag: start 
  Log:
  import
  
  Members: 
  	a:1.1->1.1.1.1 
  	b/c:1.1->1.1.1.1 
  
  ---------------------
  PatchSet 4 
  Date: * (glob)
  Author: * (glob)
  Branch: HEAD
  Tag: (none) 
  Log:
  ci0
  
  Members: 
  	b/c:1.1->1.2 
  
  ---------------------
  PatchSet 5 
  Date: * (glob)
  Author: * (glob)
  Branch: HEAD
  Tag: (none) 
  Branchpoints: branch 
  Log:
  ci1
  
  Members: 
  	a:1.1->1.2 
  
  ---------------------
  PatchSet 6 
  Date: * (glob)
  Author: * (glob)
  Branch: HEAD
  Tag: (none) 
  Log:
  ci1
  
  Members: 
  	b/c:1.2->1.3 
  
  ---------------------
  PatchSet 7 
  Date: * (glob)
  Author: * (glob)
  Branch: branch
  Tag: (none) 
  Log:
  ci2
  
  Members: 
  	b/c:1.1->1.1.2.1 
  
  ---------------------
  PatchSet 8 
  Date: * (glob)
  Author: * (glob)
  Branch: branch
  Tag: (none) 
  Log:
  funny
  ----------------------------
  log message
  
  Members: 
  	a:1.2->1.2.2.1 
  
  ---------------------
  PatchSet 9 
  Date: * (glob)
  Author: * (glob)
  Branch: branch
  Tag: (none) 
  Log:
  fuzzy
  
  Members: 
  	a:1.2.2.1->1.2.2.2 
  
  ---------------------
  PatchSet 10 
  Date: * (glob)
  Author: * (glob)
  Branch: branch
  Tag: (none) 
  Log:
  fuzzy
  
  Members: 
  	b/c:1.1.2.1->1.1.2.2 
  

  $ cd ..