view tests/test-import-eol.t @ 44363:f7459da77f23

nodemap: introduce an option to use mmap to read the nodemap mapping

The performance and memory benefit is much greater if we don't have to copy all
the data in memory for each information. So we introduce an option (on by
default) to read the data using mmap.

This changeset is the last one definition the API for index support nodemap
data. (they have to be able to use the mmaping).

Below are some benchmark comparing the best we currently have in 5.3 with the
final step of this series (using the persistent nodemap implementation in
Rust). The benchmark run `hg perfindex` with various revset and the following
variants:

Before:

 * do not use the persistent nodemap
 * use the CPython implementation of the index for nodemap
 * use mmapping of the changelog index

After:

 * use the MixedIndex Rust code, with the NodeTree object for nodemap access
   (still in review)
 * use the persistent nodemap data from disk
 * access the persistent nodemap data through mmap
 * use mmapping of the changelog index

The persistent nodemap greatly speed up  most operation on very large
repositories. Some of the previously very fast lookup end up a bit slower because
the persistent nodemap has to be setup. However the absolute slowdown is very
small and won't matters in the big picture.

Here are some numbers (in seconds) for the reference copy of mozilla-try:

Revset            Before   After     abs-change speedup

-10000:           0.004622 0.005532   0.000910  ×   0.83
-10:              0.000050 0.000132   0.000082  ×   0.37
tip               0.000052 0.000085   0.000033  ×   0.61
0 + (-10000:)     0.028222 0.005337  -0.022885  ×   5.29
0                 0.023521 0.000084  -0.023437  × 280.01
(-10000:) + 0     0.235539 0.005308  -0.230231  ×  44.37
(-10:) + :9       0.232883 0.000180  -0.232703  ×1293.79
(-10000:) + (:99) 0.238735 0.005358  -0.233377  ×  44.55
:99 + (-10000:)   0.317942 0.005593  -0.312349  ×  56.84
:9 + (-10:)       0.313372 0.000179  -0.313193  ×1750.68
:9                0.316450 0.000143  -0.316307  ×2212.93


On smaller repositories, the cost of nodemap related operation is not as big, so
the win is much more modest. Yet it helps shaving a handful of millisecond here
and there.

Here are some numbers (in seconds) for the reference copy of mercurial:

Revset            Before   After     abs-change speedup
-10:              0.000065 0.000097   0.000032  × 0.67
tip               0.000063 0.000078   0.000015  × 0.80
0                 0.000561 0.000079  -0.000482  × 7.10
-10000:           0.004609 0.003648  -0.000961  × 1.26
0 + (-10000:)     0.005023 0.003715  -0.001307  × 1.35
(-10:) + :9       0.002187 0.000108  -0.002079  ×20.25
(-10000:) + 0     0.006252 0.003716  -0.002536  × 1.68
(-10000:) + (:99) 0.006367 0.003707  -0.002660  × 1.71
:9 + (-10:)       0.003846 0.000110  -0.003736  ×34.96
:9                0.003854 0.000099  -0.003755  ×38.92
:99 + (-10000:)   0.007644 0.003778  -0.003866  × 2.02

Differential Revision: https://phab.mercurial-scm.org/D7894

  $ cat > makepatch.py <<EOF
  > import sys
  > f = open(sys.argv[2], 'wb')
  > w = f.write
  > w(b'test message\n')
  > w(b'diff --git a/a b/a\n')
  > w(b'--- a/a\n')
  > w(b'+++ b/a\n')
  > w(b'@@ -1,5 +1,5 @@\n')
  > w(b' a\n')
  > w(b'-bbb\r\n')
  > w(b'+yyyy\r\n')
  > w(b' cc\r\n')
  > w({'empty:lf': b' \n',
  >    'empty:crlf': b' \r\n',
  >    'empty:stripped-lf': b'\n',
  >    'empty:stripped-crlf': b'\r\n'}[sys.argv[1]])
  > w(b' d\n')
  > w(b'-e\n')
  > w(b'\\\\ No newline at end of file\n')
  > w(b'+z\r\n')
  > w(b'\\\\ No newline at end of file\r\n')
  > EOF

  $ hg init repo
  $ cd repo
  $ echo '\.diff' > .hgignore


Test different --eol values

  $ "$PYTHON" -c 'open("a", "wb").write(b"a\nbbb\ncc\n\nd\ne")'
  $ hg ci -Am adda
  adding .hgignore
  adding a
  $ "$PYTHON" ../makepatch.py empty:lf eol.diff
  $ "$PYTHON" ../makepatch.py empty:crlf eol-empty-crlf.diff
  $ "$PYTHON" ../makepatch.py empty:stripped-lf eol-empty-stripped-lf.diff
  $ "$PYTHON" ../makepatch.py empty:stripped-crlf eol-empty-stripped-crlf.diff

invalid eol

  $ hg --config patch.eol='LFCR' import eol.diff
  applying eol.diff
  abort: unsupported line endings type: LFCR
  [255]
  $ hg revert -a


force LF

  $ hg --traceback --config patch.eol='LF' import eol.diff
  applying eol.diff
  $ hg id
  9e4ef7b3d4af tip
  $ cat a
  a
  yyyy
  cc
  
  d
  e (no-eol)
  $ hg st

 (test empty-line variants: all of them should generate the same revision)

  $ hg up -qC 0
  $ hg --config patch.eol='LF' import eol-empty-crlf.diff
  applying eol-empty-crlf.diff
  $ hg id
  9e4ef7b3d4af tip

  $ hg up -qC 0
  $ hg --config patch.eol='LF' import eol-empty-stripped-lf.diff
  applying eol-empty-stripped-lf.diff
  $ hg id
  9e4ef7b3d4af tip

  $ hg up -qC 0
  $ hg --config patch.eol='LF' import eol-empty-stripped-crlf.diff
  applying eol-empty-stripped-crlf.diff
  $ hg id
  9e4ef7b3d4af tip

force CRLF

  $ hg up -C 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg --traceback --config patch.eol='CRLF' import eol.diff
  applying eol.diff
  $ cat a
  a\r (esc)
  yyyy\r (esc)
  cc\r (esc)
  \r (esc)
  d\r (esc)
  e (no-eol)
  $ hg st


auto EOL on LF file

  $ hg up -C 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg --traceback --config patch.eol='auto' import eol.diff
  applying eol.diff
  $ cat a
  a
  yyyy
  cc
  
  d
  e (no-eol)
  $ hg st


auto EOL on CRLF file

  $ "$PYTHON" -c 'open("a", "wb").write(b"a\r\nbbb\r\ncc\r\n\r\nd\r\ne")'
  $ hg commit -m 'switch EOLs in a'
  $ hg --traceback --config patch.eol='auto' import eol.diff
  applying eol.diff
  $ cat a
  a\r (esc)
  yyyy\r (esc)
  cc\r (esc)
  \r (esc)
  d\r (esc)
  e (no-eol)
  $ hg st


auto EOL on new file or source without any EOL

  $ "$PYTHON" -c 'open("noeol", "wb").write(b"noeol")'
  $ hg add noeol
  $ hg commit -m 'add noeol'
  $ "$PYTHON" -c 'open("noeol", "wb").write(b"noeol\r\nnoeol\n")'
  $ "$PYTHON" -c 'open("neweol", "wb").write(b"neweol\nneweol\r\n")'
  $ hg add neweol
  $ hg diff --git > noeol.diff
  $ hg revert --no-backup noeol neweol
  $ rm neweol
  $ hg --traceback --config patch.eol='auto' import -m noeol noeol.diff
  applying noeol.diff
  $ cat noeol
  noeol\r (esc)
  noeol
  $ cat neweol
  neweol
  neweol\r (esc)
  $ hg st


Test --eol and binary patches

  $ "$PYTHON" -c 'open("b", "wb").write(b"a\x00\nb\r\nd")'
  $ hg ci -Am addb
  adding b
  $ "$PYTHON" -c 'open("b", "wb").write(b"a\x00\nc\r\nd")'
  $ hg diff --git > bin.diff
  $ hg revert --no-backup b

binary patch with --eol

  $ hg import --config patch.eol='CRLF' -m changeb bin.diff
  applying bin.diff
  $ cat b
  a\x00 (esc)
  c\r (esc)
  d (no-eol)
  $ hg st
  $ cd ..