Mercurial > hg
view mercurial/exewrapper.c @ 42743:8c9a6adec67a
rust-discovery: using the children cache in add_missing
The DAG range computation often needs to get back to very old
revisions, and turns out to be disproportionately long, given
that the end goal is to remove the descendents of the given
missing revisons from the undecided set.
The fast iteration capabilities available in the Rust case make
it possible to avoid the DAG range entirely, at the cost of
precomputing the children cache, and to simply iterate on
children of the given missing revisions.
This is a case where staying on the same side of the interface
between the two languages has clear benefits.
On discoveries with initial undecided sets
small enough to bypass sampling entirely, the total cost of
computing the children cache and the subsequent iteration
becomes better than the Python + C counterpart, which relies on
reachableroots2.
For example, on a repo with more than one million revisions with
an initial undecided set of 11 elements, we get these figures:
Rust version with simple iteration
addcommons: 57.287us
first undecided computation: 184.278334ms
first children cache computation: 131.056us
addmissings iteration: 42.766us
first addinfo total: 185.24 ms
Python + C version
first addcommons: 0.29 ms
addcommons 0.21 ms
first undecided computation 191.35 ms
addmissings 45.75 ms
first addinfo total: 237.77 ms
On discoveries with large undecided sets, the initial price paid
makes the first addinfo slower than the Python + C version,
but that's more than compensated by the gain in sampling and
subsequent iterations.
Here's an extreme example with an undecided set of a million revisions:
Rust version:
first undecided computation: 293.842629ms
first children cache computation: 407.911297ms
addmissings iteration: 34.312869ms
first addinfo total: 776.02 ms
taking initial sample
query 2: sampling time: 1318.38 ms
query 2; still undecided: 1005013, sample size is: 200
addmissings: 143.062us
Python + C version:
first undecided computation 298.13 ms
addmissings 80.13 ms
first addinfo total: 399.62 ms
taking initial sample
query 2: sampling time: 3957.23 ms
query 2; still undecided: 1005013, sample size is: 200
addmissings 52.88 ms
Differential Revision: https://phab.mercurial-scm.org/D6428
author | Georges Racinet <georges.racinet@octobus.net> |
---|---|
date | Tue, 16 Apr 2019 01:16:39 +0200 |
parents | ef7119cd4965 |
children | 825d5a5907b4 |
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/* exewrapper.c - wrapper for calling a python script on Windows Copyright 2012 Adrian Buehlmann <adrian@cadifra.com> and others This software may be used and distributed according to the terms of the GNU General Public License version 2 or any later version. */ #include <Python.h> #include <stdio.h> #include <tchar.h> #include <windows.h> #include "hgpythonlib.h" #ifdef __GNUC__ int strcat_s(char *d, size_t n, const char *s) { return !strncat(d, s, n); } int strcpy_s(char *d, size_t n, const char *s) { return !strncpy(d, s, n); } #define _tcscpy_s strcpy_s #define _tcscat_s strcat_s #define _countof(array) (sizeof(array) / sizeof(array[0])) #endif static TCHAR pyscript[MAX_PATH + 10]; static TCHAR pyhome[MAX_PATH + 10]; static TCHAR pydllfile[MAX_PATH + 10]; int _tmain(int argc, TCHAR *argv[]) { TCHAR *p; int ret; int i; int n; TCHAR **pyargv; WIN32_FIND_DATA fdata; HANDLE hfind; const char *err; HMODULE pydll; void(__cdecl * Py_SetPythonHome)(TCHAR * home); int(__cdecl * Py_Main)(int argc, TCHAR *argv[]); #if PY_MAJOR_VERSION >= 3 Py_LegacyWindowsStdioFlag = 1; #endif if (GetModuleFileName(NULL, pyscript, _countof(pyscript)) == 0) { err = "GetModuleFileName failed"; goto bail; } p = _tcsrchr(pyscript, '.'); if (p == NULL) { err = "malformed module filename"; goto bail; } *p = 0; /* cut trailing ".exe" */ _tcscpy_s(pyhome, _countof(pyhome), pyscript); hfind = FindFirstFile(pyscript, &fdata); if (hfind != INVALID_HANDLE_VALUE) { /* pyscript exists, close handle */ FindClose(hfind); } else { /* file pyscript isn't there, take <pyscript>exe.py */ _tcscat_s(pyscript, _countof(pyscript), _T("exe.py")); } pydll = NULL; p = _tcsrchr(pyhome, _T('\\')); if (p == NULL) { err = "can't find backslash in module filename"; goto bail; } *p = 0; /* cut at directory */ /* check for private Python of HackableMercurial */ _tcscat_s(pyhome, _countof(pyhome), _T("\\hg-python")); hfind = FindFirstFile(pyhome, &fdata); if (hfind != INVALID_HANDLE_VALUE) { /* Path .\hg-python exists. We are probably in HackableMercurial scenario, so let's load python dll from this dir. */ FindClose(hfind); _tcscpy_s(pydllfile, _countof(pydllfile), pyhome); _tcscat_s(pydllfile, _countof(pydllfile), _T("\\") _T(HGPYTHONLIB) _T(".dll")); pydll = LoadLibrary(pydllfile); if (pydll == NULL) { err = "failed to load private Python DLL " HGPYTHONLIB ".dll"; goto bail; } Py_SetPythonHome = (void *)GetProcAddress(pydll, "Py_SetPythonHome"); if (Py_SetPythonHome == NULL) { err = "failed to get Py_SetPythonHome"; goto bail; } Py_SetPythonHome(pyhome); } if (pydll == NULL) { pydll = LoadLibrary(_T(HGPYTHONLIB) _T(".dll")); if (pydll == NULL) { err = "failed to load Python DLL " HGPYTHONLIB ".dll"; goto bail; } } Py_Main = (void *)GetProcAddress(pydll, "Py_Main"); if (Py_Main == NULL) { err = "failed to get Py_Main"; goto bail; } /* Only add the pyscript to the args, if it's not already there. It may already be there, if the script spawned a child process of itself, in the same way as it got called, that is, with the pyscript already in place. So we optionally accept the pyscript as the first argument (argv[1]), letting our exe taking the role of the python interpreter. */ if (argc >= 2 && _tcscmp(argv[1], pyscript) == 0) { /* pyscript is already in the args, so there is no need to copy the args and we can directly call the python interpreter with the original args. */ return Py_Main(argc, argv); } /* Start assembling the args for the Python interpreter call. We put the name of our exe (argv[0]) in the position where the python.exe canonically is, and insert the pyscript next. */ pyargv = malloc((argc + 5) * sizeof(TCHAR *)); if (pyargv == NULL) { err = "not enough memory"; goto bail; } n = 0; pyargv[n++] = argv[0]; pyargv[n++] = pyscript; /* copy remaining args from the command line */ for (i = 1; i < argc; i++) pyargv[n++] = argv[i]; /* argv[argc] is guaranteed to be NULL, so we forward that guarantee */ pyargv[n] = NULL; ret = Py_Main(n, pyargv); /* The Python interpreter call */ free(pyargv); return ret; bail: fprintf(stderr, "abort: %s\n", err); return 255; }