view tests/test-eol.t @ 51681:522b4d729e89

mmap: populate the mapping by default

Without pre-population, accessing all data through a mmap can result in many
pagefault, reducing performance significantly. If the mmap is prepopulated, the
performance can no longer get slower than a full read.
(See benchmark number below)

In some cases were very few data is read, prepopulating can be overkill and
slower than populating on access (through page fault). So that behavior can be
controlled when the caller can pre-determine the best behavior.
(See benchmark number below)

In addition, testing with populating in a secondary thread yield great result
combining the best of each approach. This might be implemented in later
changesets.

In all cases, using mmap has a great effect on memory usage when many processes
run in parallel on the same machine.

### Benchmarks

# What did I run

A couple of month back I ran a large benchmark campaign to assess the impact of
various approach for using mmap with the revlog (and other files), it
highlighted a few benchmarks that capture the impact of the changes well. So to
validate this change I checked the following:

- log command displaying various revisions
  (read the changelog index)
- log command displaying the patch of listed revisions
  (read the changelog index, the manifest index and a few files indexes)
- unbundling a few revisions
  (read and write changelog, manifest and few files indexes, and walk the graph
  to update some cache)
- pushing a few revisions
  (read and write changelog, manifest and few files indexes, walk the graph to
  update some cache, performs various accesses locally and remotely during
  discovery)

Benchmarks were run using the default module policy (c+py) and the rust one. No
significant difference were found between the two implementation, so we will
present result using the default policy (unless otherwise specified).

I ran them on a few repositories :

- mercurial: a "public changeset only" copy of mercurial from 2018-08-01 using
  zstd compression and sparse-revlog

- pypy: a copy of pypy from 2018-08-01 using zstd compression and sparse-revlog

- netbeans: a copy of netbeans from 2018-08-01 using zstd compression and
  sparse-revlog

- mozilla-try: a copy of mozilla-try from 2019-02-18 using zstd compression and
  sparse-revlog

- mozilla-try persistent-nodemap: Same as the above but with a persistent
  nodemap. Used for the log --patch benchmark only

# Results

For the smaller repositories (mercurial, pypy), the impact of mmap is almost
imperceptible, other cost dominating the operation. The impact of prepopulating
is undiscernible in the benchmark we ran.

For larger repositories the benchmark support explanation given above:

On netbeans, the log can be about 1% faster without repopulation (for a
difference < 100ms) but unbundle becomes a bit slower, even when small.

### data-env-vars.name                             = netbeans-2018-08-01-zstd-sparse-revlog
  # benchmark.name                                 = hg.command.unbundle
  # benchmark.variants.issue6528                   = disabled
  # benchmark.variants.reuse-external-delta-parent = yes
  # benchmark.variants.revs                        = any-1-extra-rev
  # benchmark.variants.source                      = unbundle
  # benchmark.variants.verbosity                   = quiet
with-populate: 0.240157
no-populate:   0.265087  (+10.38%, +0.02)
  # benchmark.variants.revs                        = any-100-extra-rev
with-populate: 1.459518
no-populate:   1.481290   (+1.49%, +0.02)
 ## benchmark.name                                 = hg.command.push
  # benchmark.variants.explicit-rev                = none
  # benchmark.variants.issue6528                   = disabled
  # benchmark.variants.protocol                    = ssh
  # benchmark.variants.reuse-external-delta-parent = yes
  # benchmark.variants.revs                        = any-1-extra-rev
with-populate: 0.771919
no-populate:   0.792025   (+2.60%, +0.02)
  # benchmark.variants.revs                        = any-100-extra-rev
with-populate: 1.459518
no-populate:   1.481290   (+1.49%, +0.02)


For mozilla-try, the "slow down" from pre-populate for small `hg log` is more
visible, but still small in absolute time. (using rust value for the persistent
nodemap value to be relevant).

### data-env-vars.name            = mozilla-try-2019-02-18-ds2-pnm
  # benchmark.name                = hg.command.log
  # bin-env-vars.hg.flavor        = rust
  # benchmark.variants.patch      = yes
  # benchmark.variants.limit-rev  = 1
with-populate: 0.237813
no-populate:   0.229452   (-3.52%, -0.01)
  # benchmark.variants.limit-rev  = 10
  # benchmark.variants.patch      = yes
with-populate: 1.213578
no-populate:   1.205189
### data-env-vars.name            = mozilla-try-2019-02-18-zstd-sparse-revlog
  # benchmark.variants.limit-rev  = 1000
  # benchmark.variants.patch      = no
  # benchmark.variants.rev        = tip
with-populate: 0.198607
no-populate:   0.195038   (-1.80%, -0.00)

However pre-populating provide a significant boost on more complex operations
like unbundle or push:

### data-env-vars.name                             = mozilla-try-2019-02-18-zstd-sparse-revlog
  # benchmark.name                                 = hg.command.push
  # benchmark.variants.explicit-rev                = none
  # benchmark.variants.issue6528                   = disabled
  # benchmark.variants.protocol                    = ssh
  # benchmark.variants.reuse-external-delta-parent = yes
  # benchmark.variants.revs                        = any-1-extra-rev
with-populate: 4.798632
no-populate:   4.953295   (+3.22%, +0.15)
  # benchmark.variants.revs                        = any-100-extra-rev
with-populate: 4.903618
no-populate:   5.014963   (+2.27%, +0.11)
 ## benchmark.name                                 = hg.command.unbundle
  # benchmark.variants.revs                        = any-1-extra-rev
with-populate: 1.423411
no-populate:   1.585365  (+11.38%, +0.16)
  # benchmark.variants.revs                        = any-100-extra-rev
with-populate: 1.537909
no-populate:   1.688489   (+9.79%, +0.15)

Test EOL extension

  $ cat >> $HGRCPATH <<EOF
  > [diff]
  > git = True
  > EOF

Set up helpers

  $ cat > switch-eol.py <<'EOF'
  > import os
  > import sys
  > try:
  >     import msvcrt
  >     msvcrt.setmode(sys.stdin.fileno(), os.O_BINARY)
  >     msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
  > except ImportError:
  >     pass
  > eolmap = {b'\n': '\\n', b'\r\n': '\\r\\n'}
  > (old, new) = sys.argv[1] == 'LF' and (b'\n', b'\r\n') or (b'\r\n', b'\n')
  > print("%% switching encoding from '%s' to '%s'"
  >       % (eolmap[old], eolmap[new]))
  > for path in sys.argv[2:]:
  >     data = open(path, 'rb').read()
  >     data = data.replace(old, new)
  >     open(path, 'wb').write(data)
  > EOF

  $ seteol () {
  >     if [ $1 = "LF" ]; then
  >         EOL='\n'
  >     else
  >         EOL='\r\n'
  >     fi
  > }

  $ makerepo () {
  >     seteol $1
  >     echo "% setup $1 repository"
  >     hg init repo
  >     cd repo
  >     cat > .hgeol <<EOF
  > [repository]
  > native = $1
  > [patterns]
  > mixed.txt = BIN
  > **.txt = native
  > EOF
  >     printf "first${EOL}second${EOL}third${EOL}" > a.txt
  >     hg commit --addremove -m 'checkin'
  >     echo
  >     cd ..
  > }

  $ dotest () {
  >     seteol $1
  >     echo "% hg clone repo repo-$1"
  >     hg clone --noupdate repo repo-$1
  >     cd repo-$1
  >     cat > .hg/hgrc <<EOF
  > [extensions]
  > eol =
  > [eol]
  > native = $1
  > EOF
  >     hg update
  >     echo '% a.txt'
  >     cat a.txt
  >     echo '% hg cat a.txt'
  >     hg cat a.txt
  >     printf "fourth${EOL}" >> a.txt
  >     echo '% a.txt'
  >     cat a.txt
  >     hg diff
  >     "$PYTHON" ../switch-eol.py $1 a.txt
  >     echo '% hg diff only reports a single changed line:'
  >     hg diff
  >     echo "% reverting back to $1 format"
  >     hg revert a.txt
  >     cat a.txt
  >     printf "first\r\nsecond\n" > mixed.txt
  >     hg add mixed.txt
  >     echo "% hg commit of inconsistent .txt file marked as binary (should work)"
  >     hg commit -m 'binary file'
  >     echo "% hg commit of inconsistent .txt file marked as native (should fail)"
  >     printf "first\nsecond\r\nthird\nfourth\r\n" > a.txt
  >     hg commit -m 'inconsistent file'
  >     echo "% hg commit --config eol.only-consistent=False (should work)"
  >     hg commit --config eol.only-consistent=False -m 'inconsistent file'
  >     echo "% hg commit of binary .txt file marked as native (binary files always okay)"
  >     printf "first${EOL}\0${EOL}third${EOL}" > a.txt
  >     hg commit -m 'binary file'
  >     cd ..
  >     rm -r repo-$1
  > }

  $ makemixedrepo () {
  >     echo
  >     echo "# setup $1 repository"
  >     hg init mixed
  >     cd mixed
  >     printf "foo\r\nbar\r\nbaz\r\n" > win.txt
  >     printf "foo\nbar\nbaz\n" > unix.txt
  >     #printf "foo\r\nbar\nbaz\r\n" > mixed.txt
  >     hg commit --addremove -m 'created mixed files'
  >     echo "# setting repository-native EOLs to $1"
  >     cat > .hgeol <<EOF
  > [repository]
  > native = $1
  > [patterns]
  > **.txt = native
  > EOF
  >     hg commit --addremove -m 'added .hgeol'
  >     cd ..
  > }

  $ testmixed () {
  >     echo
  >     echo "% hg clone mixed mixed-$1"
  >     hg clone mixed mixed-$1
  >     cd mixed-$1
  >     echo '% hg status (eol extension not yet activated)'
  >     hg status
  >     cat > .hg/hgrc <<EOF
  > [extensions]
  > eol =
  > [eol]
  > native = $1
  > EOF
  >     echo '% hg status (eol activated)'
  >     hg status
  >     echo '% hg commit'
  >     hg commit -m 'synchronized EOLs'
  >     echo '% hg status'
  >     hg status
  >     cd ..
  >     rm -r mixed-$1
  > }

Basic tests

  $ makerepo LF
  % setup LF repository
  adding .hgeol
  adding a.txt
  
  $ dotest LF
  % hg clone repo repo-LF
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  % a.txt
  first
  second
  third
  % hg cat a.txt
  first
  second
  third
  % a.txt
  first
  second
  third
  fourth
  diff --git a/a.txt b/a.txt
  --- a/a.txt
  +++ b/a.txt
  @@ -1,3 +1,4 @@
   first
   second
   third
  +fourth
  % switching encoding from '\n' to '\r\n'
  % hg diff only reports a single changed line:
  diff --git a/a.txt b/a.txt
  --- a/a.txt
  +++ b/a.txt
  @@ -1,3 +1,4 @@
   first
   second
   third
  +fourth
  % reverting back to LF format
  first
  second
  third
  % hg commit of inconsistent .txt file marked as binary (should work)
  % hg commit of inconsistent .txt file marked as native (should fail)
  abort: inconsistent newline style in a.txt
  
  % hg commit --config eol.only-consistent=False (should work)
  % hg commit of binary .txt file marked as native (binary files always okay)
  $ dotest CRLF
  % hg clone repo repo-CRLF
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  % a.txt
  first\r (esc)
  second\r (esc)
  third\r (esc)
  % hg cat a.txt
  first
  second
  third
  % a.txt
  first\r (esc)
  second\r (esc)
  third\r (esc)
  fourth\r (esc)
  diff --git a/a.txt b/a.txt
  --- a/a.txt
  +++ b/a.txt
  @@ -1,3 +1,4 @@
   first
   second
   third
  +fourth
  % switching encoding from '\r\n' to '\n'
  % hg diff only reports a single changed line:
  diff --git a/a.txt b/a.txt
  --- a/a.txt
  +++ b/a.txt
  @@ -1,3 +1,4 @@
   first
   second
   third
  +fourth
  % reverting back to CRLF format
  first\r (esc)
  second\r (esc)
  third\r (esc)
  % hg commit of inconsistent .txt file marked as binary (should work)
  % hg commit of inconsistent .txt file marked as native (should fail)
  abort: inconsistent newline style in a.txt
  
  % hg commit --config eol.only-consistent=False (should work)
  % hg commit of binary .txt file marked as native (binary files always okay)
  $ rm -r repo
  $ makerepo CRLF
  % setup CRLF repository
  adding .hgeol
  adding a.txt
  
  $ dotest LF
  % hg clone repo repo-LF
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  % a.txt
  first
  second
  third
  % hg cat a.txt
  first\r (esc)
  second\r (esc)
  third\r (esc)
  % a.txt
  first
  second
  third
  fourth
  diff --git a/a.txt b/a.txt
  --- a/a.txt
  +++ b/a.txt
  @@ -1,3 +1,4 @@
   first\r (esc)
   second\r (esc)
   third\r (esc)
  +fourth\r (esc)
  % switching encoding from '\n' to '\r\n'
  % hg diff only reports a single changed line:
  diff --git a/a.txt b/a.txt
  --- a/a.txt
  +++ b/a.txt
  @@ -1,3 +1,4 @@
   first\r (esc)
   second\r (esc)
   third\r (esc)
  +fourth\r (esc)
  % reverting back to LF format
  first
  second
  third
  % hg commit of inconsistent .txt file marked as binary (should work)
  % hg commit of inconsistent .txt file marked as native (should fail)
  abort: inconsistent newline style in a.txt
  
  % hg commit --config eol.only-consistent=False (should work)
  % hg commit of binary .txt file marked as native (binary files always okay)
  $ dotest CRLF
  % hg clone repo repo-CRLF
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  % a.txt
  first\r (esc)
  second\r (esc)
  third\r (esc)
  % hg cat a.txt
  first\r (esc)
  second\r (esc)
  third\r (esc)
  % a.txt
  first\r (esc)
  second\r (esc)
  third\r (esc)
  fourth\r (esc)
  diff --git a/a.txt b/a.txt
  --- a/a.txt
  +++ b/a.txt
  @@ -1,3 +1,4 @@
   first\r (esc)
   second\r (esc)
   third\r (esc)
  +fourth\r (esc)
  % switching encoding from '\r\n' to '\n'
  % hg diff only reports a single changed line:
  diff --git a/a.txt b/a.txt
  --- a/a.txt
  +++ b/a.txt
  @@ -1,3 +1,4 @@
   first\r (esc)
   second\r (esc)
   third\r (esc)
  +fourth\r (esc)
  % reverting back to CRLF format
  first\r (esc)
  second\r (esc)
  third\r (esc)
  % hg commit of inconsistent .txt file marked as binary (should work)
  % hg commit of inconsistent .txt file marked as native (should fail)
  abort: inconsistent newline style in a.txt
  
  % hg commit --config eol.only-consistent=False (should work)
  % hg commit of binary .txt file marked as native (binary files always okay)
  $ rm -r repo

Mixed tests

  $ makemixedrepo LF
  
  # setup LF repository
  adding unix.txt
  adding win.txt
  # setting repository-native EOLs to LF
  adding .hgeol
  $ testmixed LF
  
  % hg clone mixed mixed-LF
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  % hg status (eol extension not yet activated)
  % hg status (eol activated)
  M win.txt
  % hg commit
  % hg status
  $ testmixed CRLF
  
  % hg clone mixed mixed-CRLF
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  % hg status (eol extension not yet activated)
  % hg status (eol activated)
  M win.txt
  % hg commit
  % hg status
  $ rm -r mixed
  $ makemixedrepo CRLF
  
  # setup CRLF repository
  adding unix.txt
  adding win.txt
  # setting repository-native EOLs to CRLF
  adding .hgeol
  $ testmixed LF
  
  % hg clone mixed mixed-LF
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  % hg status (eol extension not yet activated)
  % hg status (eol activated)
  M unix.txt
  % hg commit
  % hg status
  $ testmixed CRLF
  
  % hg clone mixed mixed-CRLF
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  % hg status (eol extension not yet activated)
  % hg status (eol activated)
  M unix.txt
  % hg commit
  % hg status
  $ rm -r mixed

  $ echo '[extensions]' >> $HGRCPATH
  $ echo 'eol =' >> $HGRCPATH

#if unix-permissions

Test issue2569 -- eol extension takes write lock on reading:

  $ hg init repo
  $ cd repo
  $ touch .hgeol
  $ hg status
  ? .hgeol
  $ chmod -R -w .hg
  $ sleep 1
  $ touch .hgeol
  $ hg status --traceback
  ? .hgeol
  $ chmod -R u+w .hg
  $ cd ..

#endif

Test cleverencode: and cleverdecode: aliases for win32text extension

  $ cat <<EOF >> $HGRCPATH
  > [encode]
  > **.txt = cleverencode:
  > [decode]
  > **.txt = cleverdecode:
  > EOF

  $ hg init win32compat
  $ cd win32compat
  $ printf "foo\r\nbar\r\nbaz\r\n" > win.txt
  $ printf "foo\nbar\nbaz\n" > unix.txt
  $ hg add
  adding unix.txt
  adding win.txt
  $ hg commit -m checkin

Check that both files have LF line-endings in the repository:

  $ hg cat win.txt
  foo
  bar
  baz
  $ hg cat unix.txt
  foo
  bar
  baz

Test handling of a broken .hgeol file:

  $ touch .hgeol
  $ hg add .hgeol
  $ hg commit -m 'clean version'
  $ echo "bad" > .hgeol
  $ hg status
  warning: ignoring .hgeol file due to parse error at .hgeol:1: bad
  M .hgeol
  $ hg revert .hgeol
  warning: ignoring .hgeol file due to parse error at .hgeol:1: bad
  $ hg status
  ? .hgeol.orig

Test eol.only-consistent can be specified in .hgeol

  $ cd $TESTTMP
  $ hg init only-consistent
  $ cd only-consistent
  $ printf "first\nsecond\r\n" > a.txt
  $ hg add a.txt
  $ cat > .hgeol << EOF
  > [eol]
  > only-consistent = True
  > EOF
  $ hg commit -m 'inconsistent'
  abort: inconsistent newline style in a.txt
  
  [255]
  $ cat > .hgeol << EOF
  > [eol]
  > only-consistent = False
  > EOF
  $ hg commit -m 'consistent'

  $ hg init subrepo
  $ hg -R subrepo pull -qu .
  $ echo "subrepo = subrepo" > .hgsub
  $ hg ci -Am "add subrepo"
  adding .hgeol
  adding .hgsub
  $ hg archive -S ../archive
  $ find ../archive/* | sort
  ../archive/a.txt
  ../archive/subrepo
  ../archive/subrepo/a.txt
  $ cat ../archive/a.txt ../archive/subrepo/a.txt
  first\r (esc)
  second\r (esc)
  first\r (esc)
  second\r (esc)

Test trailing newline

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > eol=
  > EOF

setup repository

  $ cd $TESTTMP
  $ hg init trailing
  $ cd trailing
  $ cat > .hgeol <<EOF
  > [patterns]
  > **.txt = native
  > [eol]
  > fix-trailing-newline = False
  > EOF

add text without trailing newline

  $ printf "first\nsecond" > a.txt
  $ hg commit --addremove -m 'checking in'
  adding .hgeol
  adding a.txt
  $ rm a.txt
  $ hg update -C -q
  $ cat a.txt
  first
  second (no-eol)

  $ cat > .hgeol <<EOF
  > [patterns]
  > **.txt = native
  > [eol]
  > fix-trailing-newline = True
  > EOF
  $ printf "third\nfourth" > a.txt
  $ hg commit -m 'checking in with newline fix'
  $ rm a.txt
  $ hg update -C -q
  $ cat a.txt
  third
  fourth

append a line without trailing newline

  $ printf "fifth" >> a.txt
  $ hg commit -m 'adding another line line'
  $ rm a.txt
  $ hg update -C -q
  $ cat a.txt
  third
  fourth
  fifth

amend of changesets with renamed/deleted files expose new code paths

  $ hg mv a.txt b.txt
  $ hg ci --amend -q
  $ hg diff -c.
  diff --git a/a.txt b/b.txt
  rename from a.txt
  rename to b.txt
  --- a/a.txt
  +++ b/b.txt
  @@ -1,2 +1,3 @@
   third
   fourth
  +fifth

  $ cd ..