view tests/test-incoming-outgoing.t @ 44118:f81c17ec303c

hgdemandimport: apply lazy module loading to sys.meta_path finders

Python's `sys.meta_path` finders are the primary objects whose job it
is to find a module at import time. When `import` is called, Python
iterates objects in this list and calls `o.find_spec(...)` to find
a `ModuleSpec` (or None if the module couldn't be found by that
finder). If no meta path finder can find a module, import fails.

One of the default meta path finders is `PathFinder`. Its job is to
import modules from the filesystem and is probably the most important
importer. This finder looks at `sys.path` and `sys.path_hooks` to do
its job.

The `ModuleSpec` returned by `MetaPathImporter.find_spec()` has a
`loader` attribute, which defines the concrete module loader to use.
`sys.path_hooks` is a hook point for teaching `PathFinder` to
instantiate custom loader types.

Previously, we injected a custom `sys.path_hook` that told `PathFinder`
to wrap the default loaders with a loader that creates a module object
that is lazy.

This approach worked. But its main limitation was that it only applied
to the `PathFinder` meta path importer. There are other meta path
importers that are registered. And in the case of PyOxidizer loading
modules from memory, `PathFinder` doesn't come into play since
PyOxidizer's own meta path importer was handling all imports.

This commit changes our approach to lazy module loading by proxying
all meta path importers. Specifically, we overload the `find_spec()`
method to swap in a wrapped loader on the `ModuleSpec` before it
is returned. The end result of this is all meta path importers should
be lazy.

As much as I would have loved to utilize .__class__ manipulation to
achieve this, some meta path importers are implemented in C/Rust
in such a way that they cannot be monkeypatched. This is why we
use __getattribute__ to define a proxy.

Also, this change could theoretically open us up to regressions in
meta path importers whose loader is creating module objects which
can't be monkeypatched. But I'm not aware of any of these in the
wild. So I think we'll be safe.

According to hyperfine, this change yields a decent startup time win of
5-6ms:

```
Benchmark #1: ~/.pyenv/versions/3.6.10/bin/python ./hg version
  Time (mean ± σ):      86.8 ms ±   0.5 ms    [User: 78.0 ms, System: 8.7 ms]
  Range (min … max):    86.0 ms …  89.1 ms    50 runs

  Time (mean ± σ):      81.1 ms ±   2.7 ms    [User: 74.5 ms, System: 6.5 ms]
  Range (min … max):    77.8 ms …  90.5 ms    50 runs

Benchmark #2: ~/.pyenv/versions/3.7.6/bin/python ./hg version
  Time (mean ± σ):      78.9 ms ±   0.6 ms    [User: 70.2 ms, System: 8.7 ms]
  Range (min … max):    78.1 ms …  81.2 ms    50 runs

  Time (mean ± σ):      73.4 ms ±   0.6 ms    [User: 65.3 ms, System: 8.0 ms]
  Range (min … max):    72.4 ms …  75.7 ms    50 runs

Benchmark #3: ~/.pyenv/versions/3.8.1/bin/python ./hg version
  Time (mean ± σ):      78.1 ms ±   0.6 ms    [User: 70.2 ms, System: 7.9 ms]
  Range (min … max):    77.4 ms …  80.9 ms    50 runs

  Time (mean ± σ):      72.1 ms ±   0.4 ms    [User: 64.4 ms, System: 7.6 ms]
  Range (min … max):    71.4 ms …  74.1 ms    50 runs
```

Differential Revision: https://phab.mercurial-scm.org/D7954

#require serve

  $ hg init test
  $ cd test
  $ for i in 0 1 2 3 4 5 6 7 8; do
  >     echo $i >> foo
  >     hg commit -A -m $i
  > done
  adding foo
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 9 changesets with 9 changes to 1 files
  $ hg serve -p $HGPORT -d --pid-file=hg.pid
  $ cat hg.pid >> $DAEMON_PIDS
  $ cd ..

  $ hg init new

http incoming

  $ hg -R new incoming http://localhost:$HGPORT/
  comparing with http://localhost:$HGPORT/
  changeset:   0:00a43fa82f62
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     0
  
  changeset:   1:5460a410df01
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     1
  
  changeset:   2:d9f42cd1a1ec
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     2
  
  changeset:   3:376476025137
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     3
  
  changeset:   4:70d7eb252d49
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     4
  
  changeset:   5:ad284ee3b5ee
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     5
  
  changeset:   6:e9229f2de384
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     6
  
  changeset:   7:d152815bb8db
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     7
  
  changeset:   8:e4feb4ac9035
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     8
  
  $ hg -R new incoming -r 4 http://localhost:$HGPORT/
  comparing with http://localhost:$HGPORT/
  changeset:   0:00a43fa82f62
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     0
  
  changeset:   1:5460a410df01
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     1
  
  changeset:   2:d9f42cd1a1ec
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     2
  
  changeset:   3:376476025137
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     3
  
  changeset:   4:70d7eb252d49
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     4
  

local incoming

  $ hg -R new incoming test
  comparing with test
  changeset:   0:00a43fa82f62
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     0
  
  changeset:   1:5460a410df01
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     1
  
  changeset:   2:d9f42cd1a1ec
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     2
  
  changeset:   3:376476025137
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     3
  
  changeset:   4:70d7eb252d49
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     4
  
  changeset:   5:ad284ee3b5ee
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     5
  
  changeset:   6:e9229f2de384
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     6
  
  changeset:   7:d152815bb8db
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     7
  
  changeset:   8:e4feb4ac9035
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     8
  
  $ hg -R new incoming -r 4 test
  comparing with test
  changeset:   0:00a43fa82f62
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     0
  
  changeset:   1:5460a410df01
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     1
  
  changeset:   2:d9f42cd1a1ec
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     2
  
  changeset:   3:376476025137
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     3
  
  changeset:   4:70d7eb252d49
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     4
  

limit to 2 changesets

  $ hg -R new incoming -l 2 test
  comparing with test
  changeset:   0:00a43fa82f62
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     0
  
  changeset:   1:5460a410df01
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     1
  

limit to 2 changesets, test with -p --git

  $ hg -R new incoming -l 2 -p --git test
  comparing with test
  changeset:   0:00a43fa82f62
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     0
  
  diff --git a/foo b/foo
  new file mode 100644
  --- /dev/null
  +++ b/foo
  @@ -0,0 +1,1 @@
  +0
  
  changeset:   1:5460a410df01
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     1
  
  diff --git a/foo b/foo
  --- a/foo
  +++ b/foo
  @@ -1,1 +1,2 @@
   0
  +1
  

test with --bundle

  $ hg -R new incoming --bundle test.hg http://localhost:$HGPORT/
  comparing with http://localhost:$HGPORT/
  changeset:   0:00a43fa82f62
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     0
  
  changeset:   1:5460a410df01
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     1
  
  changeset:   2:d9f42cd1a1ec
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     2
  
  changeset:   3:376476025137
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     3
  
  changeset:   4:70d7eb252d49
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     4
  
  changeset:   5:ad284ee3b5ee
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     5
  
  changeset:   6:e9229f2de384
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     6
  
  changeset:   7:d152815bb8db
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     7
  
  changeset:   8:e4feb4ac9035
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     8
  
  $ hg -R new incoming --bundle test2.hg test
  comparing with test
  changeset:   0:00a43fa82f62
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     0
  
  changeset:   1:5460a410df01
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     1
  
  changeset:   2:d9f42cd1a1ec
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     2
  
  changeset:   3:376476025137
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     3
  
  changeset:   4:70d7eb252d49
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     4
  
  changeset:   5:ad284ee3b5ee
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     5
  
  changeset:   6:e9229f2de384
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     6
  
  changeset:   7:d152815bb8db
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     7
  
  changeset:   8:e4feb4ac9035
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     8
  


test the resulting bundles

  $ hg init temp
  $ hg init temp2
  $ hg -R temp unbundle test.hg
  adding changesets
  adding manifests
  adding file changes
  added 9 changesets with 9 changes to 1 files
  new changesets 00a43fa82f62:e4feb4ac9035 (9 drafts)
  (run 'hg update' to get a working copy)
  $ hg -R temp2 unbundle test2.hg
  adding changesets
  adding manifests
  adding file changes
  added 9 changesets with 9 changes to 1 files
  new changesets 00a43fa82f62:e4feb4ac9035 (9 drafts)
  (run 'hg update' to get a working copy)
  $ hg -R temp tip
  changeset:   8:e4feb4ac9035
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     8
  
  $ hg -R temp2 tip
  changeset:   8:e4feb4ac9035
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     8
  

  $ rm -r temp temp2 new

test outgoing

  $ hg clone test test-dev
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd test-dev
  $ for i in 9 10 11 12 13; do
  >     echo $i >> foo
  >     hg commit -A -m $i
  > done
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 14 changesets with 14 changes to 1 files
  $ cd ..
  $ hg -R test-dev outgoing test
  comparing with test
  searching for changes
  changeset:   9:d89d4abea5bc
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     9
  
  changeset:   10:820095aa7158
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     10
  
  changeset:   11:09ede2f3a638
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     11
  
  changeset:   12:e576b1bed305
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     12
  
  changeset:   13:96bbff09a7cc
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     13
  
test outgoing with secret changesets

  $ hg -R test-dev phase --force --secret 9
  $ hg -R test-dev outgoing test
  comparing with test
  searching for changes
  no changes found (ignored 5 secret changesets)
  [1]
  $ hg -R test-dev phase --draft -r 'head()'

limit to 3 changesets

  $ hg -R test-dev outgoing -l 3 test
  comparing with test
  searching for changes
  changeset:   9:d89d4abea5bc
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     9
  
  changeset:   10:820095aa7158
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     10
  
  changeset:   11:09ede2f3a638
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     11
  
  $ hg -R test-dev outgoing http://localhost:$HGPORT/
  comparing with http://localhost:$HGPORT/
  searching for changes
  changeset:   9:d89d4abea5bc
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     9
  
  changeset:   10:820095aa7158
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     10
  
  changeset:   11:09ede2f3a638
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     11
  
  changeset:   12:e576b1bed305
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     12
  
  changeset:   13:96bbff09a7cc
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     13
  
  $ hg -R test-dev outgoing -r 11 http://localhost:$HGPORT/
  comparing with http://localhost:$HGPORT/
  searching for changes
  changeset:   9:d89d4abea5bc
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     9
  
  changeset:   10:820095aa7158
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     10
  
  changeset:   11:09ede2f3a638
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     11
  

incoming from empty remote repository

  $ hg init r1
  $ hg init r2
  $ echo a > r1/foo
  $ hg -R r1 ci -Ama
  adding foo
  $ hg -R r1 incoming r2 --bundle x.hg
  comparing with r2
  searching for changes
  no changes found
  [1]

Create a "split" repo that pulls from r1 and pushes to r2, using default-push

  $ hg clone r1 split
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat > split/.hg/hgrc << EOF
  > [paths]
  > default = $TESTTMP/r3
  > default-push = $TESTTMP/r2
  > EOF
  $ hg -R split outgoing
  comparing with $TESTTMP/r2
  searching for changes
  changeset:   0:3e92d79f743a
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     a
  

Use default:pushurl instead of default-push

Windows needs a leading slash to make a URL that passes all of the checks
  $ WD=`pwd`
#if windows
  $ WD="/$WD"
#endif
  $ cat > split/.hg/hgrc << EOF
  > [paths]
  > default = $WD/r3
  > default:pushurl = file://$WD/r2
  > EOF
  $ hg -R split outgoing
  comparing with file:/*/$TESTTMP/r2 (glob)
  searching for changes
  changeset:   0:3e92d79f743a
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     a
  

Push and then double-check outgoing

  $ echo a >> split/foo
  $ hg -R split commit -Ama
  $ hg -R split push
  pushing to file:/*/$TESTTMP/r2 (glob)
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 1 files
  $ hg -R split outgoing
  comparing with file:/*/$TESTTMP/r2 (glob)
  searching for changes
  no changes found
  [1]