view tests/test-sparse-profiles.t @ 42222:57203e0210f8

copies: calculate mergecopies() based on pathcopies()

When copies are stored in changesets, we need a changeset-centric
version of mergecopies() just like we have a changeset-centric version
of pathcopies(). I think the natural way of thinking about
mergecopies() is in terms of pathcopies() from the base to each of the
commits. So if we can rewrite mergecopies() based on two such
pathcopies() calls, we'll get the changeset-centric version for
free. That's what this patch does.

A nice bonus is that it ends up being a lot simpler. mergecopies() has
accumulated a lot of technical debt over time. One good example is the
code for dealing with grafts (the "partial/incomplete/dirty"
stuff). Since pathcopies() already deals with backwards renames and
ping-pong renames, we get that for free.

I've run tests with hard-coded debug logging for "fullcopy" and while
I haven't looked at every difference it produces, all the ones I have
looked at seemed reasonable to me. I'm a little surprised that no more
tests fail when run with '--extra-config-opt
experimental.copies.read-from=compatibility' compared to before this
patch. This patch also fixes the broken cases in test-annotate.t and
test-fastannotate.t. It also enables the part of test-copies.t that
was previously disabled exactly because mergecopies() needed to get a
changeset-centric version.

One drawback of the rewritten code is that we may now make
remotefilelog prefetch more files. We used to prefetch files that were
unique to either side of the merge compared to the other. We now
prefetch files that are unique to either side of the merge compared to
the base. This means that if you added the same file to each side, we
would not prefetch it before, but we would now. Such cases are
probably quite rare, but one likely scenario where they happen is when
moving from a commit to its successor (or the other way around). The
user will probably already have the files in the cache in such cases,
so it's probably not a big deal.

Some timings for calculating mergecopies between two revisions
(revisions shown on each line, all using the common ancestor as base):

In the hg repo:
4.8 4.9: 0.21s -> 0.21s
4.0 4.8: 0.35s -> 0.63s

In and old copy of the mozilla-unified repo:
FIREFOX_BETA_60_BASE^ FIREFOX_BETA_60_BASE: 0.82s -> 0.82s
FIREFOX_NIGHTLY_59_END FIREFOX_BETA_60_BASE: 2.5s -> 2.6s
FIREFOX_BETA_59_END FIREFOX_BETA_60_BASE: 3.9s -> 4.1s
FIREFOX_AURORA_50_BASE FIREFOX_BETA_60_BASE: 31s -> 33s

So it's measurably slower in most cases. The most significant
difference is in the hg repo between revisions 4.0 and 4.8. In that
case it seems to come from the fact that pathcopies() uses
fctx.isintroducedafter() (in _tracefile), while the old mergecopies()
used fctx.linkrev() (in _checkcopies()). That results in a single call
to filectx._adjustlinkrev(), which is responsible for the entire
difference in time (in my repo). So we pay a performance penalty but
we get more correct code (see change in
test-mv-cp-st-diff.t). Deleting the "== f.filenode()" in _tracefile()
recovers the lost performance in the hg repo.

There were are few other optimizations in _checkcopies() that I could
not measure any impact from. One was from the "seen" set. Another was
from a "continue" when the file was not in the destination manifest
(corresponding to "am" in _tracefile).

Also note that merge copies are not calculated when updating with a
clean working copy, which is probably the most common case. I
therefore think the much simpler code is worth the slowdown.

Differential Revision: https://phab.mercurial-scm.org/D6255

test sparse

  $ hg init myrepo
  $ cd myrepo
  $ cat > .hg/hgrc <<EOF
  > [extensions]
  > sparse=
  > purge=
  > strip=
  > rebase=
  > EOF

Config file without [section] is rejected

  $ cat > bad.sparse <<EOF
  > *.html
  > EOF

  $ hg debugsparse --import-rules bad.sparse
  abort: sparse config entry outside of section: *.html
  (add an [include] or [exclude] line to declare the entry type)
  [255]
  $ rm bad.sparse

  $ echo a > index.html
  $ echo x > data.py
  $ echo z > readme.txt
  $ cat > webpage.sparse <<EOF
  > # frontend sparse profile
  > [include]
  > *.html
  > EOF
  $ cat > backend.sparse <<EOF
  > # backend sparse profile
  > [include]
  > *.py
  > EOF
  $ hg ci -Aqm 'initial'

  $ hg debugsparse --include '*.sparse'

Verify enabling a single profile works

  $ hg debugsparse --enable-profile webpage.sparse
  $ ls
  backend.sparse
  index.html
  webpage.sparse

Verify enabling two profiles works

  $ hg debugsparse --enable-profile backend.sparse
  $ ls
  backend.sparse
  data.py
  index.html
  webpage.sparse

Verify disabling a profile works

  $ hg debugsparse --disable-profile webpage.sparse
  $ ls
  backend.sparse
  data.py
  webpage.sparse

Verify that a profile is updated across multiple commits

  $ cat > webpage.sparse <<EOF
  > # frontend sparse profile
  > [include]
  > *.html
  > EOF
  $ cat > backend.sparse <<EOF
  > # backend sparse profile
  > [include]
  > *.py
  > *.txt
  > EOF

  $ echo foo >> data.py

  $ hg ci -m 'edit profile'
  $ ls
  backend.sparse
  data.py
  readme.txt
  webpage.sparse

  $ hg up -q 0
  $ ls
  backend.sparse
  data.py
  webpage.sparse

  $ hg up -q 1
  $ ls
  backend.sparse
  data.py
  readme.txt
  webpage.sparse

Introduce a conflicting .hgsparse change

  $ hg up -q 0
  $ cat > backend.sparse <<EOF
  > # Different backend sparse profile
  > [include]
  > *.html
  > EOF
  $ echo bar >> data.py

  $ hg ci -qAm "edit profile other"
  $ ls
  backend.sparse
  index.html
  webpage.sparse

Verify conflicting merge pulls in the conflicting changes

  $ hg merge 1
  temporarily included 2 file(s) in the sparse checkout for merging
  merging backend.sparse
  merging data.py
  warning: conflicts while merging backend.sparse! (edit, then use 'hg resolve --mark')
  warning: conflicts while merging data.py! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 2 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
  [1]

  $ rm *.orig
  $ ls
  backend.sparse
  data.py
  index.html
  webpage.sparse

Verify resolving the merge removes the temporarily unioned files

  $ cat > backend.sparse <<EOF
  > # backend sparse profile
  > [include]
  > *.html
  > *.txt
  > EOF
  $ hg resolve -m backend.sparse

  $ cat > data.py <<EOF
  > x
  > foo
  > bar
  > EOF
  $ hg resolve -m data.py
  (no more unresolved files)

  $ hg ci -qAm "merge profiles"
  $ ls
  backend.sparse
  index.html
  readme.txt
  webpage.sparse

  $ hg cat -r . data.py
  x
  foo
  bar

Verify stripping refreshes dirstate

  $ hg strip -q -r .
  $ ls
  backend.sparse
  index.html
  webpage.sparse

Verify rebase conflicts pulls in the conflicting changes

  $ hg up -q 1
  $ ls
  backend.sparse
  data.py
  readme.txt
  webpage.sparse

  $ hg rebase -d 2
  rebasing 1:a2b1de640a62 "edit profile"
  temporarily included 2 file(s) in the sparse checkout for merging
  merging backend.sparse
  merging data.py
  warning: conflicts while merging backend.sparse! (edit, then use 'hg resolve --mark')
  warning: conflicts while merging data.py! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]
  $ rm *.orig
  $ ls
  backend.sparse
  data.py
  index.html
  webpage.sparse

Verify resolving conflict removes the temporary files

  $ cat > backend.sparse <<EOF
  > [include]
  > *.html
  > *.txt
  > EOF
  $ hg resolve -m backend.sparse

  $ cat > data.py <<EOF
  > x
  > foo
  > bar
  > EOF
  $ hg resolve -m data.py
  (no more unresolved files)
  continue: hg rebase --continue

  $ hg rebase -q --continue
  $ ls
  backend.sparse
  index.html
  readme.txt
  webpage.sparse

  $ hg cat -r . data.py
  x
  foo
  bar

Test checking out a commit that does not contain the sparse profile. The
warning message can be suppressed by setting missingwarning = false in
[sparse] section of your config:

  $ hg debugsparse --reset
  $ hg rm *.sparse
  $ hg commit -m "delete profiles"
  $ hg up -q ".^"
  $ hg debugsparse --enable-profile backend.sparse
  $ ls
  index.html
  readme.txt
  $ hg up tip | grep warning
  warning: sparse profile 'backend.sparse' not found in rev bfcb76de99cc - ignoring it
  [1]
  $ ls
  data.py
  index.html
  readme.txt
  $ hg debugsparse --disable-profile backend.sparse | grep warning
  warning: sparse profile 'backend.sparse' not found in rev bfcb76de99cc - ignoring it
  [1]
  $ cat >> .hg/hgrc <<EOF
  > [sparse]
  > missingwarning = false
  > EOF
  $ hg debugsparse --enable-profile backend.sparse

  $ cd ..

#if unix-permissions

Test file permissions changing across a sparse profile change
  $ hg init sparseperm
  $ cd sparseperm
  $ cat > .hg/hgrc <<EOF
  > [extensions]
  > sparse=
  > EOF
  $ touch a b
  $ cat > .hgsparse <<EOF
  > [include]
  > a
  > EOF
  $ hg commit -Aqm 'initial'
  $ chmod a+x b
  $ hg commit -qm 'make executable'
  $ cat >> .hgsparse <<EOF
  > b
  > EOF
  $ hg commit -qm 'update profile'
  $ hg up -q 0
  $ hg debugsparse --enable-profile .hgsparse
  $ hg up -q 2
  $ ls -l b
  -rwxr-xr-x* b (glob)

#endif