branchcache: add a "pure topological head" fast path
In a narrow but actually quick common case, all topological heads are all on
the same branch and all open. In this case, computing the branch map is very
simple. We can quickly detect situation where this situation will not change.
So we update the V3 format to be able to express this situation and upgrade the
update code to detect we remains in that mode.
The branch cache is populated with the actual value when the branch map is
accessed, but the update_disk method can do the update without needing to
populate it.
/*
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
_wputenv(L"PYTHONLEGACYWINDOWSSTDIO=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;
}