view tests/test-config-env.py @ 52176:72bc29f01570

revlog: add glue to use a pure-Rust VFS

This will save us a lot of calling back into Python, which is always
horribly expensive.

We are now faster in all benchmarked cases except for `log --patch`
specifically on mozilla-try. Fixing this will happen in a later patch.

```
### data-env-vars.name            = mercurial-devel-2024-03-22-ds2-pnm
  # benchmark.name                = hg.command.cat
  # bin-env-vars.hg.flavor        = rust
  # bin-env-vars.hg.py-re2-module = default
  # benchmark.variants.files      = all-root
  # benchmark.variants.output     = plain
  # benchmark.variants.rev        = tip
e679697a6ca4: 1.760765  ~~~~~
5559d7e63ec3: 1.555513  (-11.66%, -0.21)
### data-env-vars.name            = mozilla-try-2024-03-26-ds2-pnm
  # benchmark.name                = hg.command.cat
  # bin-env-vars.hg.flavor        = rust
  # bin-env-vars.hg.py-re2-module = default
  # benchmark.variants.files      = all-root
  # benchmark.variants.output     = plain
  # benchmark.variants.rev        = tip
e679697a6ca4: 62.848869  ~~~~~
5559d7e63ec3: 58.113051   (-7.54%, -4.74)
### data-env-vars.name            = mozilla-try-2024-03-26-ds2-pnm
  # benchmark.name                = hg.command.log
  # bin-env-vars.hg.flavor        = rust
  # bin-env-vars.hg.py-re2-module = default
  # benchmark.variants.limit-rev  = 10
  # benchmark.variants.patch      = yes
  # benchmark.variants.rev        = none
e679697a6ca4: 3.173532  ~~~~~
5559d7e63ec3: 3.543591  (+11.66%, +0.37)
### data-env-vars.name            = mozilla-try-2024-03-26-ds2-pnm
  # benchmark.name                = hg.command.log
  # bin-env-vars.hg.flavor        = rust
  # bin-env-vars.hg.py-re2-module = default
  # benchmark.variants.limit-rev  = 1000
  # benchmark.variants.patch      = no
  # benchmark.variants.rev        = none
e679697a6ca4: 1.214698  ~~~~~
5559d7e63ec3: 1.192478   (-1.83%, -0.02)
### data-env-vars.name            = mozilla-unified-2024-03-22-ds2-pnm
  # benchmark.name                = hg.command.cat
  # bin-env-vars.hg.flavor        = rust
  # bin-env-vars.hg.py-re2-module = default
  # benchmark.variants.files      = all-root
  # benchmark.variants.output     = plain
  # benchmark.variants.rev        = tip
e679697a6ca4: 56.205474  ~~~~~
5559d7e63ec3: 51.520074   (-8.34%, -4.69)
### data-env-vars.name            = mozilla-unified-2024-03-22-ds2-pnm
  # benchmark.name                = hg.command.log
  # bin-env-vars.hg.flavor        = rust
  # bin-env-vars.hg.py-re2-module = default
  # benchmark.variants.limit-rev  = 10
  # benchmark.variants.patch      = yes
  # benchmark.variants.rev        = none
e679697a6ca4: 2.105419  ~~~~~
5559d7e63ec3: 2.051849   (-2.54%, -0.05)
### data-env-vars.name            = mozilla-unified-2024-03-22-ds2-pnm
  # benchmark.name                = hg.command.log
  # bin-env-vars.hg.flavor        = rust
  # bin-env-vars.hg.py-re2-module = default
  # benchmark.variants.limit-rev  = 1000
  # benchmark.variants.patch      = no
  # benchmark.variants.rev        = none
e679697a6ca4: 0.309960  ~~~~~
5559d7e63ec3: 0.299035   (-3.52%, -0.01)
### data-env-vars.name            = tryton-public-2024-03-22-ds2-pnm
  # benchmark.name                = hg.command.cat
  # bin-env-vars.hg.flavor        = rust
  # bin-env-vars.hg.py-re2-module = default
  # benchmark.variants.files      = all-root
  # benchmark.variants.output     = plain
  # benchmark.variants.rev        = tip
e679697a6ca4: 1.849832  ~~~~~
5559d7e63ec3: 1.805076   (-2.42%, -0.04)
### data-env-vars.name            = tryton-public-2024-03-22-ds2-pnm
  # benchmark.name                = hg.command.log
  # bin-env-vars.hg.flavor        = rust
  # bin-env-vars.hg.py-re2-module = default
  # benchmark.variants.limit-rev  = 10
  # benchmark.variants.patch      = yes
  # benchmark.variants.rev        = none
e679697a6ca4: 0.289521  ~~~~~
5559d7e63ec3: 0.279889   (-3.33%, -0.01)
### data-env-vars.name            = tryton-public-2024-03-22-ds2-pnm
  # benchmark.name                = hg.command.log
  # bin-env-vars.hg.flavor        = rust
  # bin-env-vars.hg.py-re2-module = default
  # benchmark.variants.limit-rev  = 1000
  # benchmark.variants.patch      = no
  # benchmark.variants.rev        = none
e679697a6ca4: 0.332270  ~~~~~
5559d7e63ec3: 0.323324   (-2.69%, -0.01)
```

# Test the config layer generated by environment variables


import os

from mercurial import (
    encoding,
    extensions,
    rcutil,
    ui as uimod,
    util,
)

from mercurial.utils import procutil

testtmp = encoding.environ[b'TESTTMP']


# prepare hgrc files
def join(name):
    return os.path.join(testtmp, name)


with open(join(b'sysrc'), 'wb') as f:
    f.write(b'[ui]\neditor=e0\n[pager]\npager=p0\n')

with open(join(b'userrc'), 'wb') as f:
    f.write(b'[ui]\neditor=e1')


# replace rcpath functions so they point to the files above
def systemrcpath():
    return [join(b'sysrc')]


def userrcpath():
    return [join(b'userrc')]


extensions.wrapfunction(rcutil, 'default_rc_resources', lambda orig: [])

rcutil.systemrcpath = systemrcpath
rcutil.userrcpath = userrcpath


# utility to print configs
def printconfigs(env):
    encoding.environ = env
    rcutil._rccomponents = None  # reset cache
    ui = uimod.ui.load()
    for section, name, value in ui.walkconfig():
        source = ui.configsource(section, name)
        procutil.stdout.write(
            b'%s.%s=%s # %s\n' % (section, name, value, util.pconvert(source))
        )
    procutil.stdout.write(b'\n')


# environment variable overrides
printconfigs({})
printconfigs({b'EDITOR': b'e2', b'PAGER': b'p2'})