Mercurial > hg
diff mercurial/util.py @ 48940:2974cdda819b
util: remove iterfile() variant for buggy EINTR handling
The workaround for Python 2 is no longer needed. So we can delete some
code.
Differential Revision: https://phab.mercurial-scm.org/D12346
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Thu, 03 Mar 2022 07:56:47 -0800 |
parents | f254fc73d956 |
children | 642e31cb55f0 |
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--- a/mercurial/util.py Mon Feb 21 12:36:57 2022 -0700 +++ b/mercurial/util.py Thu Mar 03 07:56:47 2022 -0800 @@ -25,7 +25,6 @@ import locale import mmap import os -import platform as pyplatform import re as remod import shutil import stat @@ -2905,50 +2904,10 @@ fromnativeeol = pycompat.identity nativeeolwriter = pycompat.identity -if pyplatform.python_implementation() == b'CPython' and sys.version_info < ( - 3, - 0, -): - # There is an issue in CPython that some IO methods do not handle EINTR - # correctly. The following table shows what CPython version (and functions) - # are affected (buggy: has the EINTR bug, okay: otherwise): - # - # | < 2.7.4 | 2.7.4 to 2.7.12 | >= 3.0 - # -------------------------------------------------- - # fp.__iter__ | buggy | buggy | okay - # fp.read* | buggy | okay [1] | okay - # - # [1]: fixed by changeset 67dc99a989cd in the cpython hg repo. - # - # Here we workaround the EINTR issue for fileobj.__iter__. Other methods - # like "read*" work fine, as we do not support Python < 2.7.4. - # - # Although we can workaround the EINTR issue for fp.__iter__, it is slower: - # "for x in fp" is 4x faster than "for x in iter(fp.readline, '')" in - # CPython 2, because CPython 2 maintains an internal readahead buffer for - # fp.__iter__ but not other fp.read* methods. - # - # On modern systems like Linux, the "read" syscall cannot be interrupted - # when reading "fast" files like on-disk files. So the EINTR issue only - # affects things like pipes, sockets, ttys etc. We treat "normal" (S_ISREG) - # files approximately as "fast" files and use the fast (unsafe) code path, - # to minimize the performance impact. - - def iterfile(fp): - fastpath = True - if type(fp) is file: - fastpath = stat.S_ISREG(os.fstat(fp.fileno()).st_mode) - if fastpath: - return fp - else: - # fp.readline deals with EINTR correctly, use it as a workaround. - return iter(fp.readline, b'') - - -else: - # PyPy and CPython 3 do not have the EINTR issue thus no workaround needed. - def iterfile(fp): - return fp + +# TODO delete since workaround variant for Python 2 no longer needed. +def iterfile(fp): + return fp def iterlines(iterator):