tests: drop test-demandimport.py distutils test that failed with warnings The test would fail because warnings: /usr/lib/python3.11/site-packages/_distutils_hack/__init__.py:18: UserWarning: Distutils was imported before Setuptools, but importing Setuptools also replaces the `distutils` module in `sys.modules`. This may lead to undesirable behaviors or errors. To avoid these issues, avoid using distutils directly, ensure that setuptools is installed in the traditional way (e.g. not an editable install), and/or make sure that setuptools is always imported before distutils. warnings.warn( /usr/lib/python3.11/site-packages/_distutils_hack/__init__.py:33: UserWarning: Setuptools is replacing distutils. warnings.warn("Setuptools is replacing distutils.") The test for distutils.msvc9compiler comes from 2205d00b6d2b. But since then, distutils is going away, and this test must change somehow. It is unclear exactly how setuptools depended on msvc9compiler, but setuptools also moved forward, and this exact test no longer seems relevant. It thus seems like a fair solution to remove the test while keeping the demandimport blacklist of distutils.msvc9compiler.

utils: test coverage of makedate Explore the scenario from ae04af1ce78d to avoid future regressions. This was intended to give some coverage of the change in faccec1edc2c.

mmap: populate mapping in a background thread When possible, we populate the memory mapping in a second thread. The mmap population does not only read the data from disk to memory. It also actually fill the memory mapping between process memory address and the physical memory used by the file system cache containing the mmap'ed data. Doing so buy back the slowdown from pre-population when it matters. When most data is accessed, only a few page fault will occurs, while the background thread fill the memory controller. When few data is accessed, the non-blocking mmap won't have to wait for all data to be populated. Here is a few example of improvement seen in benchmark around unbundle and push: ### data-env-vars.name = netbeans-2018-08-01-zstd-sparse-revlog # benchmark.name = hg.command.unbundle # benchmark.variants.issue6528 = disabled # benchmark.variants.reuse-external-delta-parent = yes # benchmark.variants.revs = any-100-extra-rev before: 0.758101 after: 0.732129 (-3.43%, -0.03) ## data-env-vars.name = mozilla-try-2019-02-18-zstd-sparse-revlog before: 1.519941 after: 1.503473 (-1.08%, -0.02) ### data-env-vars.name = mozilla-try-2019-02-18-zstd-sparse-revlog # benchmark.name = hg.command.push # bin-env-vars.hg.flavor = default # benchmark.variants.issue6528 = disabled # benchmark.variants.protocol = ssh # benchmark.variants.reuse-external-delta-parent = yes # benchmark.variants.revs = any-1-extra-rev before: 4.801442 after: 4.695810 (-1.46%, -0.07) # benchmark.variants.revs = any-100-extra-rev before: 4.848596 after: 4.794075 (-1.12%, -0.05) # bin-env-vars.hg.flavor = rust # benchmark.variants.revs = any-1-extra-rev before: 4.818410 after: 4.700053 (-2.46%, -0.12)

pure: stringify builtin exception messages Builtin exceptions usually want strings, and display with a wierd b'' prefix if given bytes.

httppeer: avoid another bad reference before assignment warning This wasn't a problem, because `b''` from the `AttributeError` handler is in `bundle2.bundletypes`, so the following loop and conditional always run at least once. But PyCharm can't figure that out on its own, and it took a little exploring to figure out it wasn't a problem. The usage in `bundle2.writebundle` is to look it up in the map of bundle types, so it will break in a more obvious way in the unlikely event that the empty string is removed from the map in the future.

httppeer: move a variable to avoid a bad reference before assignment warning No actual bug here, because the conditional used to assign is the same as the conditional in the `finally` block that guards the reference.

httppeer: simplify two-way stream cleanup No need to conditionalize the cleanup if the filename is assigned outside the exception handler. I suppose `fd` leaks if `os.fdopen()` fails, but that was the case before too (and may trigger another exception in the `finally` block on Windows, when the file is still open).