Mercurial > hg-stable
view mercurial/osutil.c @ 27015:341cb90ffd18
util: disable floating point stat times (issue4836)
Alternate fix for this issue which avoids putting extra function calls
and exception handling in the fast path.
For almost all purposes, integer timestamps are preferable to
Mercurial. It stores integer timestamps in the dirstate and would thus
like to avoid doing any float/int comparisons or conversions. We will
continue to have to deal with 1-second granularity on filesystems for
quite some time, so this won't significantly hinder our capabilities.
This has some impact on our file cache validation code in that it
lowers timestamp resolution. But as we still have to deal with
low-resolution filesystems, we're not relying on this anyway.
An alternate approach is to use stat[ST_MTIME], which is guaranteed to
be an integer. But since this support isn't already in our extension,
we can't depend on it being available without adding a hard Python->C
API dependency that's painful for people like yours truly who have
bisect regularly and people without compilers.
author | Matt Mackall <mpm@selenic.com> |
---|---|
date | Thu, 19 Nov 2015 13:21:24 -0600 |
parents | f9f2f29ce023 |
children | 34a37a2e03e6 |
line wrap: on
line source
/* osutil.c - native operating system services Copyright 2007 Matt Mackall and others This software may be used and distributed according to the terms of the GNU General Public License, incorporated herein by reference. */ #define _ATFILE_SOURCE #include <Python.h> #include <fcntl.h> #include <stdio.h> #include <string.h> #include <errno.h> #ifdef _WIN32 #include <windows.h> #include <io.h> #else #include <dirent.h> #include <sys/stat.h> #include <sys/types.h> #include <unistd.h> #endif #ifdef __APPLE__ #include <sys/attr.h> #include <sys/vnode.h> #endif #include "util.h" /* some platforms lack the PATH_MAX definition (eg. GNU/Hurd) */ #ifndef PATH_MAX #define PATH_MAX 4096 #endif #ifdef _WIN32 /* stat struct compatible with hg expectations Mercurial only uses st_mode, st_size and st_mtime the rest is kept to minimize changes between implementations */ struct hg_stat { int st_dev; int st_mode; int st_nlink; __int64 st_size; int st_mtime; int st_ctime; }; struct listdir_stat { PyObject_HEAD struct hg_stat st; }; #else struct listdir_stat { PyObject_HEAD struct stat st; }; #endif #define listdir_slot(name) \ static PyObject *listdir_stat_##name(PyObject *self, void *x) \ { \ return PyInt_FromLong(((struct listdir_stat *)self)->st.name); \ } listdir_slot(st_dev) listdir_slot(st_mode) listdir_slot(st_nlink) #ifdef _WIN32 static PyObject *listdir_stat_st_size(PyObject *self, void *x) { return PyLong_FromLongLong( (PY_LONG_LONG)((struct listdir_stat *)self)->st.st_size); } #else listdir_slot(st_size) #endif listdir_slot(st_mtime) listdir_slot(st_ctime) static struct PyGetSetDef listdir_stat_getsets[] = { {"st_dev", listdir_stat_st_dev, 0, 0, 0}, {"st_mode", listdir_stat_st_mode, 0, 0, 0}, {"st_nlink", listdir_stat_st_nlink, 0, 0, 0}, {"st_size", listdir_stat_st_size, 0, 0, 0}, {"st_mtime", listdir_stat_st_mtime, 0, 0, 0}, {"st_ctime", listdir_stat_st_ctime, 0, 0, 0}, {0, 0, 0, 0, 0} }; static PyObject *listdir_stat_new(PyTypeObject *t, PyObject *a, PyObject *k) { return t->tp_alloc(t, 0); } static void listdir_stat_dealloc(PyObject *o) { o->ob_type->tp_free(o); } static PyTypeObject listdir_stat_type = { PyVarObject_HEAD_INIT(NULL, 0) "osutil.stat", /*tp_name*/ sizeof(struct listdir_stat), /*tp_basicsize*/ 0, /*tp_itemsize*/ (destructor)listdir_stat_dealloc, /*tp_dealloc*/ 0, /*tp_print*/ 0, /*tp_getattr*/ 0, /*tp_setattr*/ 0, /*tp_compare*/ 0, /*tp_repr*/ 0, /*tp_as_number*/ 0, /*tp_as_sequence*/ 0, /*tp_as_mapping*/ 0, /*tp_hash */ 0, /*tp_call*/ 0, /*tp_str*/ 0, /*tp_getattro*/ 0, /*tp_setattro*/ 0, /*tp_as_buffer*/ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/ "stat objects", /* tp_doc */ 0, /* tp_traverse */ 0, /* tp_clear */ 0, /* tp_richcompare */ 0, /* tp_weaklistoffset */ 0, /* tp_iter */ 0, /* tp_iternext */ 0, /* tp_methods */ 0, /* tp_members */ listdir_stat_getsets, /* tp_getset */ 0, /* tp_base */ 0, /* tp_dict */ 0, /* tp_descr_get */ 0, /* tp_descr_set */ 0, /* tp_dictoffset */ 0, /* tp_init */ 0, /* tp_alloc */ listdir_stat_new, /* tp_new */ }; #ifdef _WIN32 static int to_python_time(const FILETIME *tm) { /* number of seconds between epoch and January 1 1601 */ const __int64 a0 = (__int64)134774L * (__int64)24L * (__int64)3600L; /* conversion factor from 100ns to 1s */ const __int64 a1 = 10000000; /* explicit (int) cast to suspend compiler warnings */ return (int)((((__int64)tm->dwHighDateTime << 32) + tm->dwLowDateTime) / a1 - a0); } static PyObject *make_item(const WIN32_FIND_DATAA *fd, int wantstat) { PyObject *py_st; struct hg_stat *stp; int kind = (fd->dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) ? _S_IFDIR : _S_IFREG; if (!wantstat) return Py_BuildValue("si", fd->cFileName, kind); py_st = PyObject_CallObject((PyObject *)&listdir_stat_type, NULL); if (!py_st) return NULL; stp = &((struct listdir_stat *)py_st)->st; /* use kind as st_mode rwx bits on Win32 are meaningless and Hg does not use them anyway */ stp->st_mode = kind; stp->st_mtime = to_python_time(&fd->ftLastWriteTime); stp->st_ctime = to_python_time(&fd->ftCreationTime); if (kind == _S_IFREG) stp->st_size = ((__int64)fd->nFileSizeHigh << 32) + fd->nFileSizeLow; return Py_BuildValue("siN", fd->cFileName, kind, py_st); } static PyObject *_listdir(char *path, int plen, int wantstat, char *skip) { PyObject *rval = NULL; /* initialize - return value */ PyObject *list; HANDLE fh; WIN32_FIND_DATAA fd; char *pattern; /* build the path + \* pattern string */ pattern = malloc(plen + 3); /* path + \* + \0 */ if (!pattern) { PyErr_NoMemory(); goto error_nomem; } strcpy(pattern, path); if (plen > 0) { char c = path[plen-1]; if (c != ':' && c != '/' && c != '\\') pattern[plen++] = '\\'; } strcpy(pattern + plen, "*"); fh = FindFirstFileA(pattern, &fd); if (fh == INVALID_HANDLE_VALUE) { PyErr_SetFromWindowsErrWithFilename(GetLastError(), path); goto error_file; } list = PyList_New(0); if (!list) goto error_list; do { PyObject *item; if (fd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) { if (!strcmp(fd.cFileName, ".") || !strcmp(fd.cFileName, "..")) continue; if (skip && !strcmp(fd.cFileName, skip)) { rval = PyList_New(0); goto error; } } item = make_item(&fd, wantstat); if (!item) goto error; if (PyList_Append(list, item)) { Py_XDECREF(item); goto error; } Py_XDECREF(item); } while (FindNextFileA(fh, &fd)); if (GetLastError() != ERROR_NO_MORE_FILES) { PyErr_SetFromWindowsErrWithFilename(GetLastError(), path); goto error; } rval = list; Py_XINCREF(rval); error: Py_XDECREF(list); error_list: FindClose(fh); error_file: free(pattern); error_nomem: return rval; } #else int entkind(struct dirent *ent) { #ifdef DT_REG switch (ent->d_type) { case DT_REG: return S_IFREG; case DT_DIR: return S_IFDIR; case DT_LNK: return S_IFLNK; case DT_BLK: return S_IFBLK; case DT_CHR: return S_IFCHR; case DT_FIFO: return S_IFIFO; case DT_SOCK: return S_IFSOCK; } #endif return -1; } static PyObject *makestat(const struct stat *st) { PyObject *stat; stat = PyObject_CallObject((PyObject *)&listdir_stat_type, NULL); if (stat) memcpy(&((struct listdir_stat *)stat)->st, st, sizeof(*st)); return stat; } static PyObject *_listdir_stat(char *path, int pathlen, int keepstat, char *skip) { PyObject *list, *elem, *stat = NULL, *ret = NULL; char fullpath[PATH_MAX + 10]; int kind, err; struct stat st; struct dirent *ent; DIR *dir; #ifdef AT_SYMLINK_NOFOLLOW int dfd = -1; #endif if (pathlen >= PATH_MAX) { errno = ENAMETOOLONG; PyErr_SetFromErrnoWithFilename(PyExc_OSError, path); goto error_value; } strncpy(fullpath, path, PATH_MAX); fullpath[pathlen] = '/'; #ifdef AT_SYMLINK_NOFOLLOW dfd = open(path, O_RDONLY); if (dfd == -1) { PyErr_SetFromErrnoWithFilename(PyExc_OSError, path); goto error_value; } dir = fdopendir(dfd); #else dir = opendir(path); #endif if (!dir) { PyErr_SetFromErrnoWithFilename(PyExc_OSError, path); goto error_dir; } list = PyList_New(0); if (!list) goto error_list; while ((ent = readdir(dir))) { if (!strcmp(ent->d_name, ".") || !strcmp(ent->d_name, "..")) continue; kind = entkind(ent); if (kind == -1 || keepstat) { #ifdef AT_SYMLINK_NOFOLLOW err = fstatat(dfd, ent->d_name, &st, AT_SYMLINK_NOFOLLOW); #else strncpy(fullpath + pathlen + 1, ent->d_name, PATH_MAX - pathlen); fullpath[PATH_MAX] = '\0'; err = lstat(fullpath, &st); #endif if (err == -1) { /* race with file deletion? */ if (errno == ENOENT) continue; strncpy(fullpath + pathlen + 1, ent->d_name, PATH_MAX - pathlen); fullpath[PATH_MAX] = 0; PyErr_SetFromErrnoWithFilename(PyExc_OSError, fullpath); goto error; } kind = st.st_mode & S_IFMT; } /* quit early? */ if (skip && kind == S_IFDIR && !strcmp(ent->d_name, skip)) { ret = PyList_New(0); goto error; } if (keepstat) { stat = makestat(&st); if (!stat) goto error; elem = Py_BuildValue("siN", ent->d_name, kind, stat); } else elem = Py_BuildValue("si", ent->d_name, kind); if (!elem) goto error; stat = NULL; PyList_Append(list, elem); Py_DECREF(elem); } ret = list; Py_INCREF(ret); error: Py_DECREF(list); Py_XDECREF(stat); error_list: closedir(dir); error_dir: #ifdef AT_SYMLINK_NOFOLLOW close(dfd); #endif error_value: return ret; } #ifdef __APPLE__ typedef struct { u_int32_t length; attrreference_t name; fsobj_type_t obj_type; struct timespec mtime; #if __LITTLE_ENDIAN__ mode_t access_mask; uint16_t padding; #else uint16_t padding; mode_t access_mask; #endif off_t size; } __attribute__((packed)) attrbuf_entry; int attrkind(attrbuf_entry *entry) { switch (entry->obj_type) { case VREG: return S_IFREG; case VDIR: return S_IFDIR; case VLNK: return S_IFLNK; case VBLK: return S_IFBLK; case VCHR: return S_IFCHR; case VFIFO: return S_IFIFO; case VSOCK: return S_IFSOCK; } return -1; } /* get these many entries at a time */ #define LISTDIR_BATCH_SIZE 50 static PyObject *_listdir_batch(char *path, int pathlen, int keepstat, char *skip, bool *fallback) { PyObject *list, *elem, *stat = NULL, *ret = NULL; int kind, err; unsigned long index; unsigned int count, old_state, new_state; bool state_seen = false; attrbuf_entry *entry; /* from the getattrlist(2) man page: a path can be no longer than (NAME_MAX * 3 + 1) bytes. Also, "The getattrlist() function will silently truncate attribute data if attrBufSize is too small." So pass in a buffer big enough for the worst case. */ char attrbuf[LISTDIR_BATCH_SIZE * (sizeof(attrbuf_entry) + NAME_MAX * 3 + 1)]; unsigned int basep_unused; struct stat st; int dfd = -1; /* these must match the attrbuf_entry struct, otherwise you'll end up with garbage */ struct attrlist requested_attr = {0}; requested_attr.bitmapcount = ATTR_BIT_MAP_COUNT; requested_attr.commonattr = (ATTR_CMN_NAME | ATTR_CMN_OBJTYPE | ATTR_CMN_MODTIME | ATTR_CMN_ACCESSMASK); requested_attr.fileattr = ATTR_FILE_TOTALSIZE; *fallback = false; if (pathlen >= PATH_MAX) { errno = ENAMETOOLONG; PyErr_SetFromErrnoWithFilename(PyExc_OSError, path); goto error_value; } dfd = open(path, O_RDONLY); if (dfd == -1) { PyErr_SetFromErrnoWithFilename(PyExc_OSError, path); goto error_value; } list = PyList_New(0); if (!list) goto error_dir; do { count = LISTDIR_BATCH_SIZE; err = getdirentriesattr(dfd, &requested_attr, &attrbuf, sizeof(attrbuf), &count, &basep_unused, &new_state, 0); if (err < 0) { if (errno == ENOTSUP) { /* We're on a filesystem that doesn't support getdirentriesattr. Fall back to the stat-based implementation. */ *fallback = true; } else PyErr_SetFromErrnoWithFilename(PyExc_OSError, path); goto error; } if (!state_seen) { old_state = new_state; state_seen = true; } else if (old_state != new_state) { /* There's an edge case with getdirentriesattr. Consider the following initial list of files: a b <-- c d If the iteration is paused at the arrow, and b is deleted before it is resumed, getdirentriesattr will not return d at all! Ordinarily we're expected to restart the iteration from the beginning. To avoid getting stuck in a retry loop here, fall back to stat. */ *fallback = true; goto error; } entry = (attrbuf_entry *)attrbuf; for (index = 0; index < count; index++) { char *filename = ((char *)&entry->name) + entry->name.attr_dataoffset; if (!strcmp(filename, ".") || !strcmp(filename, "..")) continue; kind = attrkind(entry); if (kind == -1) { PyErr_Format(PyExc_OSError, "unknown object type %u for file " "%s%s!", entry->obj_type, path, filename); goto error; } /* quit early? */ if (skip && kind == S_IFDIR && !strcmp(filename, skip)) { ret = PyList_New(0); goto error; } if (keepstat) { /* from the getattrlist(2) man page: "Only the permission bits ... are valid". */ st.st_mode = (entry->access_mask & ~S_IFMT) | kind; st.st_mtime = entry->mtime.tv_sec; st.st_size = entry->size; stat = makestat(&st); if (!stat) goto error; elem = Py_BuildValue("siN", filename, kind, stat); } else elem = Py_BuildValue("si", filename, kind); if (!elem) goto error; stat = NULL; PyList_Append(list, elem); Py_DECREF(elem); entry = (attrbuf_entry *)((char *)entry + entry->length); } } while (err == 0); ret = list; Py_INCREF(ret); error: Py_DECREF(list); Py_XDECREF(stat); error_dir: close(dfd); error_value: return ret; } #endif /* __APPLE__ */ static PyObject *_listdir(char *path, int pathlen, int keepstat, char *skip) { #ifdef __APPLE__ PyObject *ret; bool fallback = false; ret = _listdir_batch(path, pathlen, keepstat, skip, &fallback); if (ret != NULL || !fallback) return ret; #endif return _listdir_stat(path, pathlen, keepstat, skip); } static PyObject *statfiles(PyObject *self, PyObject *args) { PyObject *names, *stats; Py_ssize_t i, count; if (!PyArg_ParseTuple(args, "O:statfiles", &names)) return NULL; count = PySequence_Length(names); if (count == -1) { PyErr_SetString(PyExc_TypeError, "not a sequence"); return NULL; } stats = PyList_New(count); if (stats == NULL) return NULL; for (i = 0; i < count; i++) { PyObject *stat, *pypath; struct stat st; int ret, kind; char *path; /* With a large file count or on a slow filesystem, don't block signals for long (issue4878). */ if ((i % 1000) == 999 && PyErr_CheckSignals() == -1) goto bail; pypath = PySequence_GetItem(names, i); if (!pypath) goto bail; path = PyString_AsString(pypath); if (path == NULL) { Py_DECREF(pypath); PyErr_SetString(PyExc_TypeError, "not a string"); goto bail; } ret = lstat(path, &st); Py_DECREF(pypath); kind = st.st_mode & S_IFMT; if (ret != -1 && (kind == S_IFREG || kind == S_IFLNK)) { stat = makestat(&st); if (stat == NULL) goto bail; PyList_SET_ITEM(stats, i, stat); } else { Py_INCREF(Py_None); PyList_SET_ITEM(stats, i, Py_None); } } return stats; bail: Py_DECREF(stats); return NULL; } #endif /* ndef _WIN32 */ static PyObject *listdir(PyObject *self, PyObject *args, PyObject *kwargs) { PyObject *statobj = NULL; /* initialize - optional arg */ PyObject *skipobj = NULL; /* initialize - optional arg */ char *path, *skip = NULL; int wantstat, plen; static char *kwlist[] = {"path", "stat", "skip", NULL}; if (!PyArg_ParseTupleAndKeywords(args, kwargs, "s#|OO:listdir", kwlist, &path, &plen, &statobj, &skipobj)) return NULL; wantstat = statobj && PyObject_IsTrue(statobj); if (skipobj && skipobj != Py_None) { skip = PyBytes_AsString(skipobj); if (!skip) return NULL; } return _listdir(path, plen, wantstat, skip); } #ifdef _WIN32 static PyObject *posixfile(PyObject *self, PyObject *args, PyObject *kwds) { static char *kwlist[] = {"name", "mode", "buffering", NULL}; PyObject *file_obj = NULL; char *name = NULL; char *mode = "rb"; DWORD access = 0; DWORD creation; HANDLE handle; int fd, flags = 0; int bufsize = -1; char m0, m1, m2; char fpmode[4]; int fppos = 0; int plus; FILE *fp; if (!PyArg_ParseTupleAndKeywords(args, kwds, "et|si:posixfile", kwlist, Py_FileSystemDefaultEncoding, &name, &mode, &bufsize)) return NULL; m0 = mode[0]; m1 = m0 ? mode[1] : '\0'; m2 = m1 ? mode[2] : '\0'; plus = m1 == '+' || m2 == '+'; fpmode[fppos++] = m0; if (m1 == 'b' || m2 == 'b') { flags = _O_BINARY; fpmode[fppos++] = 'b'; } else flags = _O_TEXT; if (m0 == 'r' && !plus) { flags |= _O_RDONLY; access = GENERIC_READ; } else { /* work around http://support.microsoft.com/kb/899149 and set _O_RDWR for 'w' and 'a', even if mode has no '+' */ flags |= _O_RDWR; access = GENERIC_READ | GENERIC_WRITE; fpmode[fppos++] = '+'; } fpmode[fppos++] = '\0'; switch (m0) { case 'r': creation = OPEN_EXISTING; break; case 'w': creation = CREATE_ALWAYS; break; case 'a': creation = OPEN_ALWAYS; flags |= _O_APPEND; break; default: PyErr_Format(PyExc_ValueError, "mode string must begin with one of 'r', 'w', " "or 'a', not '%c'", m0); goto bail; } handle = CreateFile(name, access, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL, creation, FILE_ATTRIBUTE_NORMAL, 0); if (handle == INVALID_HANDLE_VALUE) { PyErr_SetFromWindowsErrWithFilename(GetLastError(), name); goto bail; } fd = _open_osfhandle((intptr_t)handle, flags); if (fd == -1) { CloseHandle(handle); PyErr_SetFromErrnoWithFilename(PyExc_IOError, name); goto bail; } #ifndef IS_PY3K fp = _fdopen(fd, fpmode); if (fp == NULL) { _close(fd); PyErr_SetFromErrnoWithFilename(PyExc_IOError, name); goto bail; } file_obj = PyFile_FromFile(fp, name, mode, fclose); if (file_obj == NULL) { fclose(fp); goto bail; } PyFile_SetBufSize(file_obj, bufsize); #else file_obj = PyFile_FromFd(fd, name, mode, bufsize, NULL, NULL, NULL, 1); if (file_obj == NULL) goto bail; #endif bail: PyMem_Free(name); return file_obj; } #endif #ifdef __APPLE__ #include <ApplicationServices/ApplicationServices.h> static PyObject *isgui(PyObject *self) { CFDictionaryRef dict = CGSessionCopyCurrentDictionary(); if (dict != NULL) { CFRelease(dict); Py_RETURN_TRUE; } else { Py_RETURN_FALSE; } } #endif static char osutil_doc[] = "Native operating system services."; static PyMethodDef methods[] = { {"listdir", (PyCFunction)listdir, METH_VARARGS | METH_KEYWORDS, "list a directory\n"}, #ifdef _WIN32 {"posixfile", (PyCFunction)posixfile, METH_VARARGS | METH_KEYWORDS, "Open a file with POSIX-like semantics.\n" "On error, this function may raise either a WindowsError or an IOError."}, #else {"statfiles", (PyCFunction)statfiles, METH_VARARGS | METH_KEYWORDS, "stat a series of files or symlinks\n" "Returns None for non-existent entries and entries of other types.\n"}, #endif #ifdef __APPLE__ { "isgui", (PyCFunction)isgui, METH_NOARGS, "Is a CoreGraphics session available?" }, #endif {NULL, NULL} }; #ifdef IS_PY3K static struct PyModuleDef osutil_module = { PyModuleDef_HEAD_INIT, "osutil", osutil_doc, -1, methods }; PyMODINIT_FUNC PyInit_osutil(void) { if (PyType_Ready(&listdir_stat_type) < 0) return NULL; return PyModule_Create(&osutil_module); } #else PyMODINIT_FUNC initosutil(void) { if (PyType_Ready(&listdir_stat_type) == -1) return; Py_InitModule3("osutil", methods, osutil_doc); } #endif