view tests/test-copies-in-changeset.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

#testcases extra sidedata

#if extra
  $ cat >> $HGRCPATH << EOF
  > [experimental]
  > copies.write-to=changeset-only
  > copies.read-from=changeset-only
  > [alias]
  > changesetcopies = log -r . -T 'files: {files}
  >   {extras % "{ifcontains("files", key, "{key}: {value}\n")}"}
  >   {extras % "{ifcontains("copies", key, "{key}: {value}\n")}"}'
  > EOF
#endif

#if sidedata
  $ cat >> $HGRCPATH << EOF
  > [format]
  > exp-use-copies-side-data-changeset = yes
  > EOF
#endif

  $ cat >> $HGRCPATH << EOF
  > [alias]
  > showcopies = log -r . -T '{file_copies % "{source} -> {name}\n"}'
  > [extensions]
  > rebase =
  > split =
  > EOF

Check that copies are recorded correctly

  $ hg init repo
  $ cd repo
#if sidedata
  $ hg debugformat -v
  format-variant    repo config default
  fncache:           yes    yes     yes
  dotencode:         yes    yes     yes
  generaldelta:      yes    yes     yes
  sparserevlog:      yes    yes     yes
  sidedata:          yes    yes      no
  copies-sdc:        yes    yes      no
  plain-cl-delta:    yes    yes     yes
  compression:       zlib   zlib    zlib
  compression-level: default default default
#else
  $ hg debugformat -v
  format-variant    repo config default
  fncache:           yes    yes     yes
  dotencode:         yes    yes     yes
  generaldelta:      yes    yes     yes
  sparserevlog:      yes    yes     yes
  sidedata:           no     no      no
  copies-sdc:         no     no      no
  plain-cl-delta:    yes    yes     yes
  compression:       zlib   zlib    zlib
  compression-level: default default default
#endif
  $ echo a > a
  $ hg add a
  $ hg ci -m initial
  $ hg cp a b
  $ hg cp a c
  $ hg cp a d
  $ hg ci -m 'copy a to b, c, and d'

#if extra

  $ hg changesetcopies
  files: b c d
  filesadded: 0
  1
  2
  
  p1copies: 0\x00a (esc)
  1\x00a (esc)
  2\x00a (esc)
#else
  $ hg debugsidedata -c -v -- -1
  2 sidedata entries
   entry-0010 size 11
    '0\x00a\n1\x00a\n2\x00a'
   entry-0012 size 5
    '0\n1\n2'
#endif

  $ hg showcopies
  a -> b
  a -> c
  a -> d

#if extra

  $ hg showcopies --config experimental.copies.read-from=compatibility
  a -> b
  a -> c
  a -> d
  $ hg showcopies --config experimental.copies.read-from=filelog-only

#endif

Check that renames are recorded correctly

  $ hg mv b b2
  $ hg ci -m 'rename b to b2'

#if extra

  $ hg changesetcopies
  files: b b2
  filesadded: 1
  filesremoved: 0
  
  p1copies: 1\x00b (esc)

#else
  $ hg debugsidedata -c -v -- -1
  3 sidedata entries
   entry-0010 size 3
    '1\x00b'
   entry-0012 size 1
    '1'
   entry-0013 size 1
    '0'
#endif

  $ hg showcopies
  b -> b2


Rename onto existing file. This should get recorded in the changeset files list and in the extras,
even though there is no filelog entry.

  $ hg cp b2 c --force
  $ hg st --copies
  M c
    b2

#if extra

  $ hg debugindex c
     rev linkrev nodeid       p1           p2
       0       1 b789fdd96dc2 000000000000 000000000000

#else

  $ hg debugindex c
     rev linkrev nodeid       p1           p2
       0       1 37d9b5d994ea 000000000000 000000000000

#endif


  $ hg ci -m 'move b onto d'

#if extra

  $ hg changesetcopies
  files: c
  
  p1copies: 0\x00b2 (esc)

#else
  $ hg debugsidedata -c -v -- -1
  1 sidedata entries
   entry-0010 size 4
    '0\x00b2'
#endif

  $ hg showcopies
  b2 -> c

#if extra

  $ hg debugindex c
     rev linkrev nodeid       p1           p2
       0       1 b789fdd96dc2 000000000000 000000000000

#else

  $ hg debugindex c
     rev linkrev nodeid       p1           p2
       0       1 37d9b5d994ea 000000000000 000000000000
       1       3 029625640347 000000000000 000000000000

#endif

Create a merge commit with copying done during merge.

  $ hg co 0
  0 files updated, 0 files merged, 3 files removed, 0 files unresolved
  $ hg cp a e
  $ hg cp a f
  $ hg ci -m 'copy a to e and f'
  created new head
  $ hg merge 3
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
File 'a' exists on both sides, so 'g' could be recorded as being from p1 or p2, but we currently
always record it as being from p1
  $ hg cp a g
File 'd' exists only in p2, so 'h' should be from p2
  $ hg cp d h
File 'f' exists only in p1, so 'i' should be from p1
  $ hg cp f i
  $ hg ci -m 'merge'

#if extra

  $ hg changesetcopies
  files: g h i
  filesadded: 0
  1
  2
  
  p1copies: 0\x00a (esc)
  2\x00f (esc)
  p2copies: 1\x00d (esc)

#else
  $ hg debugsidedata -c -v -- -1
  3 sidedata entries
   entry-0010 size 7
    '0\x00a\n2\x00f'
   entry-0011 size 3
    '1\x00d'
   entry-0012 size 5
    '0\n1\n2'
#endif

  $ hg showcopies
  a -> g
  d -> h
  f -> i

Test writing to both changeset and filelog

  $ hg cp a j
#if extra
  $ hg ci -m 'copy a to j' --config experimental.copies.write-to=compatibility
  $ hg changesetcopies
  files: j
  filesadded: 0
  filesremoved: 
  
  p1copies: 0\x00a (esc)
  p2copies: 
#else
  $ hg ci -m 'copy a to j'
  $ hg debugsidedata -c -v -- -1
  2 sidedata entries
   entry-0010 size 3
    '0\x00a'
   entry-0012 size 1
    '0'
#endif
  $ hg debugdata j 0
  \x01 (esc)
  copy: a
  copyrev: b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3
  \x01 (esc)
  a
  $ hg showcopies
  a -> j
  $ hg showcopies --config experimental.copies.read-from=compatibility
  a -> j
  $ hg showcopies --config experimental.copies.read-from=filelog-only
  a -> j
Existing copy information in the changeset gets removed on amend and writing
copy information on to the filelog
#if extra
  $ hg ci --amend -m 'copy a to j, v2' \
  > --config experimental.copies.write-to=filelog-only
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/*-*-amend.hg (glob)
  $ hg changesetcopies
  files: j
  
#else
  $ hg ci --amend -m 'copy a to j, v2'
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/*-*-amend.hg (glob)
  $ hg debugsidedata -c -v -- -1
  2 sidedata entries
   entry-0010 size 3
    '0\x00a'
   entry-0012 size 1
    '0'
#endif
  $ hg showcopies --config experimental.copies.read-from=filelog-only
  a -> j
The entries should be written to extras even if they're empty (so the client
won't have to fall back to reading from filelogs)
  $ echo x >> j
#if extra
  $ hg ci -m 'modify j' --config experimental.copies.write-to=compatibility
  $ hg changesetcopies
  files: j
  filesadded: 
  filesremoved: 
  
  p1copies: 
  p2copies: 
#else
  $ hg ci -m 'modify j'
  $ hg debugsidedata -c -v -- -1
#endif

Test writing only to filelog

  $ hg cp a k
#if extra
  $ hg ci -m 'copy a to k' --config experimental.copies.write-to=filelog-only

  $ hg changesetcopies
  files: k
  
#else
  $ hg ci -m 'copy a to k'
  $ hg debugsidedata -c -v -- -1
  2 sidedata entries
   entry-0010 size 3
    '0\x00a'
   entry-0012 size 1
    '0'
#endif

  $ hg debugdata k 0
  \x01 (esc)
  copy: a
  copyrev: b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3
  \x01 (esc)
  a
#if extra
  $ hg showcopies

  $ hg showcopies --config experimental.copies.read-from=compatibility
  a -> k
  $ hg showcopies --config experimental.copies.read-from=filelog-only
  a -> k
#else
  $ hg showcopies
  a -> k
#endif

  $ cd ..

Test rebasing a commit with copy information

  $ hg init rebase-rename
  $ cd rebase-rename
  $ echo a > a
  $ hg ci -Aqm 'add a'
  $ echo a2 > a
  $ hg ci -m 'modify a'
  $ hg co -q 0
  $ hg mv a b
  $ hg ci -qm 'rename a to b'
  $ hg rebase -d 1 --config rebase.experimental.inmemory=yes
  rebasing 2:* "rename a to b" (tip) (glob)
  merging a and b to b
  saved backup bundle to $TESTTMP/rebase-rename/.hg/strip-backup/*-*-rebase.hg (glob)
  $ hg st --change . --copies
  A b
    a
  R a
  $ cd ..

Test splitting a commit

  $ hg init split
  $ cd split
  $ echo a > a
  $ echo b > b
  $ hg ci -Aqm 'add a and b'
  $ echo a2 > a
  $ hg mv b c
  $ hg ci -m 'modify a, move b to c'
  $ hg --config ui.interactive=yes split <<EOF
  > y
  > y
  > n
  > y
  > EOF
  diff --git a/a b/a
  1 hunks, 1 lines changed
  examine changes to 'a'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -1,1 +1,1 @@
  -a
  +a2
  record this change to 'a'?
  (enter ? for help) [Ynesfdaq?] y
  
  diff --git a/b b/c
  rename from b
  rename to c
  examine changes to 'b' and 'c'?
  (enter ? for help) [Ynesfdaq?] n
  
  created new head
  diff --git a/b b/c
  rename from b
  rename to c
  examine changes to 'b' and 'c'?
  (enter ? for help) [Ynesfdaq?] y
  
  saved backup bundle to $TESTTMP/split/.hg/strip-backup/*-*-split.hg (glob)
  $ cd ..

Test committing half a rename

  $ hg init partial
  $ cd partial
  $ echo a > a
  $ hg ci -Aqm 'add a'
  $ hg mv a b
  $ hg ci -m 'remove a' a

#if sidedata

Test upgrading/downgrading to sidedata storage
==============================================

downgrading (keeping some sidedata)

  $ hg debugformat -v
  format-variant    repo config default
  fncache:           yes    yes     yes
  dotencode:         yes    yes     yes
  generaldelta:      yes    yes     yes
  sparserevlog:      yes    yes     yes
  sidedata:          yes    yes      no
  copies-sdc:        yes    yes      no
  plain-cl-delta:    yes    yes     yes
  compression:       zlib   zlib    zlib
  compression-level: default default default
  $ hg debugsidedata -c -- 0
  1 sidedata entries
   entry-0012 size 1
  $ hg debugsidedata -c -- 1
  1 sidedata entries
   entry-0013 size 1
  $ hg debugsidedata -m -- 0
  $ cat << EOF > .hg/hgrc
  > [format]
  > exp-use-side-data = yes
  > exp-use-copies-side-data-changeset = no
  > EOF
  $ hg debugupgraderepo --run --quiet --no-backup > /dev/null
  $ hg debugformat -v
  format-variant    repo config default
  fncache:           yes    yes     yes
  dotencode:         yes    yes     yes
  generaldelta:      yes    yes     yes
  sparserevlog:      yes    yes     yes
  sidedata:          yes    yes      no
  copies-sdc:         no     no      no
  plain-cl-delta:    yes    yes     yes
  compression:       zlib   zlib    zlib
  compression-level: default default default
  $ hg debugsidedata -c -- 0
  $ hg debugsidedata -c -- 1
  $ hg debugsidedata -m -- 0

upgrading

  $ cat << EOF > .hg/hgrc
  > [format]
  > exp-use-copies-side-data-changeset = yes
  > EOF
  $ hg debugupgraderepo --run --quiet --no-backup > /dev/null
  $ hg debugformat -v
  format-variant    repo config default
  fncache:           yes    yes     yes
  dotencode:         yes    yes     yes
  generaldelta:      yes    yes     yes
  sparserevlog:      yes    yes     yes
  sidedata:          yes    yes      no
  copies-sdc:        yes    yes      no
  plain-cl-delta:    yes    yes     yes
  compression:       zlib   zlib    zlib
  compression-level: default default default
  $ hg debugsidedata -c -- 0
  1 sidedata entries
   entry-0012 size 1
  $ hg debugsidedata -c -- 1
  1 sidedata entries
   entry-0013 size 1
  $ hg debugsidedata -m -- 0

#endif

  $ cd ..