[PATCH 1 of 2 V2] win32: add a method to fetch the available pipe data size
Matt Harbison
mharbison72 at gmail.com
Wed Apr 8 03:30:41 UTC 2015
# HG changeset patch
# User Matt Harbison <matt_harbison at yahoo.com>
# Date 1428460225 14400
# Tue Apr 07 22:30:25 2015 -0400
# Node ID baeeb5f4bd5980f8722221156bbee3c3329c448b
# Parent 54e5c239c2d9ad87fc2080fd9be35765cf0ebc9f
win32: add a method to fetch the available pipe data size
This will be used in the next patch to do nonblocking reads from the child
process, like on posix platforms. See that for why os.fstat() is insufficient.
diff --git a/mercurial/win32.py b/mercurial/win32.py
--- a/mercurial/win32.py
+++ b/mercurial/win32.py
@@ -5,7 +5,7 @@
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
-import ctypes, errno, os, subprocess, random
+import ctypes, errno, msvcrt, os, subprocess, random
_kernel32 = ctypes.windll.kernel32
_advapi32 = ctypes.windll.advapi32
@@ -26,6 +26,7 @@
_ERROR_SUCCESS = 0
_ERROR_NO_MORE_FILES = 18
_ERROR_INVALID_PARAMETER = 87
+_ERROR_BROKEN_PIPE = 109
_ERROR_INSUFFICIENT_BUFFER = 122
# WPARAM is defined as UINT_PTR (unsigned type)
@@ -211,6 +212,10 @@
_kernel32.CreateToolhelp32Snapshot.argtypes = [_DWORD, _DWORD]
_kernel32.CreateToolhelp32Snapshot.restype = _BOOL
+_kernel32.PeekNamedPipe.argtypes = [_HANDLE, ctypes.c_void_p, _DWORD,
+ ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p]
+_kernel32.PeekNamedPipe.restype = _BOOL
+
_kernel32.Process32First.argtypes = [_HANDLE, ctypes.c_void_p]
_kernel32.Process32First.restype = _BOOL
@@ -260,6 +265,22 @@
res2 = _getfileinfo(path2)
return res1.dwVolumeSerialNumber == res2.dwVolumeSerialNumber
+def peekpipe(pipe):
+ handle = msvcrt.get_osfhandle(pipe.fileno())
+ if handle == -1:
+ raise ctypes.WinError()
+
+ avail = _DWORD()
+
+ if not _kernel32.PeekNamedPipe(handle, None, 0, None, ctypes.byref(avail),
+ None):
+ err = _kernel32.GetLastError()
+ if err == _ERROR_BROKEN_PIPE:
+ return 0
+ raise ctypes.WinError(err)
+
+ return avail.value
+
def testpid(pid):
'''return True if pid is still running or unable to
determine, False otherwise'''
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