view tests/test-repo-compengines.t @ 40424:7caf632e30c3

filecache: unimplement __set__() and __delete__() (API)

Implementing __set__() implies that the descriptor can't be overridden by
obj.__dict__, which means any property access involves slow function call.

  "Data descriptors with __set__() and __get__() defined always override
  a redefinition in an instance dictionary. In contrast, non-data descriptors
  can be overridden by instances."

  https://docs.python.org/2.7/reference/datamodel.html#invoking-descriptors

This patch basically backs out 236bb604dc39, "scmutil: update cached copy
when filecached attribute is assigned (issue3263)." The problem described
in issue3263 (which is #3264 in Bugzilla) should no longer happen since
repo._bookmarkcurrent has been moved to repo._bookmarks.active. We still
have a risk of introducing similar bugs, but I think that's the cost we
have to pay.

  $ hg perfrevset 'branch(tip)' -R mercurial
  (orig) wall 0.139511 comb 0.140000 user 0.140000 sys 0.000000 (best of 66)
  (prev) wall 0.114195 comb 0.110000 user 0.110000 sys 0.000000 (best of 81)
  (this) wall 0.099038 comb 0.110000 user 0.100000 sys 0.010000 (best of 93)

A new repository uses zlib storage, which doesn't need a requirement

  $ hg init default
  $ cd default
  $ cat .hg/requires
  dotencode
  fncache
  generaldelta
  revlogv1
  store
  testonly-simplestore (reposimplestore !)

  $ touch foo
  $ hg -q commit -A -m 'initial commit with a lot of repeated repeated repeated text to trigger compression'
  $ hg debugrevlog -c | grep 0x78
      0x78 (x)  :   1 (100.00%)
      0x78 (x)  : 110 (100.00%)

  $ cd ..

Unknown compression engine to format.compression aborts

  $ hg --config experimental.format.compression=unknown init unknown
  abort: compression engine unknown defined by experimental.format.compression not available
  (run "hg debuginstall" to list available compression engines)
  [255]

A requirement specifying an unknown compression engine results in bail

  $ hg init unknownrequirement
  $ cd unknownrequirement
  $ echo exp-compression-unknown >> .hg/requires
  $ hg log
  abort: repository requires features unknown to this Mercurial: exp-compression-unknown!
  (see https://mercurial-scm.org/wiki/MissingRequirement for more information)
  [255]

  $ cd ..

#if zstd

  $ hg --config experimental.format.compression=zstd init zstd
  $ cd zstd
  $ cat .hg/requires
  dotencode
  exp-compression-zstd
  fncache
  generaldelta
  revlogv1
  store
  testonly-simplestore (reposimplestore !)

  $ touch foo
  $ hg -q commit -A -m 'initial commit with a lot of repeated repeated repeated text'

  $ hg debugrevlog -c | grep 0x28
      0x28      :  1 (100.00%)
      0x28      : 98 (100.00%)

  $ cd ..

Specifying a new format.compression on an existing repo won't introduce data
with that engine or a requirement

  $ cd default
  $ touch bar
  $ hg --config experimental.format.compression=zstd -q commit -A -m 'add bar with a lot of repeated repeated repeated text'

  $ cat .hg/requires
  dotencode
  fncache
  generaldelta
  revlogv1
  store
  testonly-simplestore (reposimplestore !)

  $ hg debugrevlog -c | grep 0x78
      0x78 (x)  :   2 (100.00%)
      0x78 (x)  : 199 (100.00%)

#endif