view tests/test-sparse-profiles.t @ 39492:a33f394b2bfd

snapshot: try intermediate snapshot against parents' base

# Regarding The Series Started By This Changeset

This is the first changesets of a group adjusting delta chain strategy to
build a useful chain of intermediate snapshots. The series will introduce a
full strategy to produce chains of multiple snapshots on top of which a
"usual" delta chain will be built.

That strategy will have multiple steps to maximize snapshot reuse, avoiding
pathological cases and improving overall compression in very branchy
repositories. An important property of sparse-revlog using such snapshot-chain
is that they can use very short delta chain without problematic impact on the
resulting compression. Shorter delta chains are important to achieve good
performance.

To make each step clear, we'll introduce them one by one.

See the end of this series for full details.

# Regarding This Changeset

Before this change, if we cannot store the current revision as a delta against
a "simple" candidate (p1, p2, prev), we created a new level-0 snapshot (also
called full snapshot).

As the first step, we introduce a simple strategy: try an intermediate level-1
snapshot against the chain base of the "current revision" parents.
The "current revision" is the one we are currently trying to store in the
revlog, triggering this search for a good delta base.
The first item in the chain is always a level-0 snapshot.

# Effect On The Test Repository

We can already see the effect on the test-repository. Most of the snapshots
have shifted from level 0 to level 1. The overall size has slightly decreased.
(However, keep in mind that this repository only emulates real data)

# Regarding Statistic

The current series focuses on improving the chain built. Improving the
performance of this logic will be done as a second step. Sparse-revlog is
still experimental and disabled by default.

We'll provide more statistic about resulting size and delta chain at the end
of this series.

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 1 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 1 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