mercurial/cext/parsers.c
author Joerg Sonnenberger <joerg@bec.de>
Wed, 06 Dec 2017 15:46:41 +0100
changeset 35309 d13526333835
parent 34862 d92dc725223b
child 36619 1f8c3fadbb8e
permissions -rw-r--r--
phases: drop the list with phase of each rev, always comput phase sets Change the C implementation of phasecache.loadphaserevs to provide only the sets for draft and secret phase as well as the number of revisions seen. Change the pure Python implementation of the same functino to compute the sets instead of the list of phases for each revision. Change phasecache.phase to check the phase sets and assume public if the revision is in neither draft nor secret set. This is computationally slightly more expensive. Change phasecache.getrevset for public() based queries to compute the set of non-matching revisions and return the result as filtered fullreposet. A shortcut is taken when no draft or secret revision exists. Bump the module version for the changed interface contract. Overall, this saves around 16 Bytes per revision whenever the phasecache is used, for the test case in issue5691 it is around 3MB. getrevset() for a large repository is around 13% slower here, that seems an acceptable trade off. Performance impact for phase() should be similar. Differential Revision: https://phab.mercurial-scm.org/D1606

/*
 parsers.c - efficient content parsing

 Copyright 2008 Matt Mackall <mpm@selenic.com> and others

 This software may be used and distributed according to the terms of
 the GNU General Public License, incorporated herein by reference.
*/

#include <Python.h>
#include <ctype.h>
#include <stddef.h>
#include <string.h>

#include "bitmanipulation.h"
#include "charencode.h"
#include "util.h"

#ifdef IS_PY3K
/* The mapping of Python types is meant to be temporary to get Python
 * 3 to compile. We should remove this once Python 3 support is fully
 * supported and proper types are used in the extensions themselves. */
#define PyInt_Check PyLong_Check
#define PyInt_FromLong PyLong_FromLong
#define PyInt_FromSsize_t PyLong_FromSsize_t
#define PyInt_AsLong PyLong_AsLong
#endif

static const char *const versionerrortext = "Python minor version mismatch";

static PyObject *dict_new_presized(PyObject *self, PyObject *args)
{
	Py_ssize_t expected_size;

	if (!PyArg_ParseTuple(args, "n:make_presized_dict", &expected_size))
		return NULL;

	return _dict_new_presized(expected_size);
}

/*
 * This code assumes that a manifest is stitched together with newline
 * ('\n') characters.
 */
static PyObject *parse_manifest(PyObject *self, PyObject *args)
{
	PyObject *mfdict, *fdict;
	char *str, *start, *end;
	int len;

	if (!PyArg_ParseTuple(args, "O!O!s#:parse_manifest", &PyDict_Type,
	                      &mfdict, &PyDict_Type, &fdict, &str, &len))
		goto quit;

	start = str;
	end = str + len;
	while (start < end) {
		PyObject *file = NULL, *node = NULL;
		PyObject *flags = NULL;
		char *zero = NULL, *newline = NULL;
		ptrdiff_t nlen;

		zero = memchr(start, '\0', end - start);
		if (!zero) {
			PyErr_SetString(PyExc_ValueError,
			                "manifest entry has no separator");
			goto quit;
		}

		newline = memchr(zero + 1, '\n', end - (zero + 1));
		if (!newline) {
			PyErr_SetString(PyExc_ValueError,
			                "manifest contains trailing garbage");
			goto quit;
		}

		file = PyBytes_FromStringAndSize(start, zero - start);

		if (!file)
			goto bail;

		nlen = newline - zero - 1;

		node = unhexlify(zero + 1, nlen > 40 ? 40 : (Py_ssize_t)nlen);
		if (!node)
			goto bail;

		if (nlen > 40) {
			flags = PyBytes_FromStringAndSize(zero + 41, nlen - 40);
			if (!flags)
				goto bail;

			if (PyDict_SetItem(fdict, file, flags) == -1)
				goto bail;
		}

		if (PyDict_SetItem(mfdict, file, node) == -1)
			goto bail;

		start = newline + 1;

		Py_XDECREF(flags);
		Py_XDECREF(node);
		Py_XDECREF(file);
		continue;
	bail:
		Py_XDECREF(flags);
		Py_XDECREF(node);
		Py_XDECREF(file);
		goto quit;
	}

	Py_INCREF(Py_None);
	return Py_None;
quit:
	return NULL;
}

static inline dirstateTupleObject *make_dirstate_tuple(char state, int mode,
                                                       int size, int mtime)
{
	dirstateTupleObject *t =
	    PyObject_New(dirstateTupleObject, &dirstateTupleType);
	if (!t)
		return NULL;
	t->state = state;
	t->mode = mode;
	t->size = size;
	t->mtime = mtime;
	return t;
}

static PyObject *dirstate_tuple_new(PyTypeObject *subtype, PyObject *args,
                                    PyObject *kwds)
{
	/* We do all the initialization here and not a tp_init function because
	 * dirstate_tuple is immutable. */
	dirstateTupleObject *t;
	char state;
	int size, mode, mtime;
	if (!PyArg_ParseTuple(args, "ciii", &state, &mode, &size, &mtime))
		return NULL;

	t = (dirstateTupleObject *)subtype->tp_alloc(subtype, 1);
	if (!t)
		return NULL;
	t->state = state;
	t->mode = mode;
	t->size = size;
	t->mtime = mtime;

	return (PyObject *)t;
}

static void dirstate_tuple_dealloc(PyObject *o)
{
	PyObject_Del(o);
}

static Py_ssize_t dirstate_tuple_length(PyObject *o)
{
	return 4;
}

static PyObject *dirstate_tuple_item(PyObject *o, Py_ssize_t i)
{
	dirstateTupleObject *t = (dirstateTupleObject *)o;
	switch (i) {
	case 0:
		return PyBytes_FromStringAndSize(&t->state, 1);
	case 1:
		return PyInt_FromLong(t->mode);
	case 2:
		return PyInt_FromLong(t->size);
	case 3:
		return PyInt_FromLong(t->mtime);
	default:
		PyErr_SetString(PyExc_IndexError, "index out of range");
		return NULL;
	}
}

static PySequenceMethods dirstate_tuple_sq = {
    dirstate_tuple_length, /* sq_length */
    0,                     /* sq_concat */
    0,                     /* sq_repeat */
    dirstate_tuple_item,   /* sq_item */
    0,                     /* sq_ass_item */
    0,                     /* sq_contains */
    0,                     /* sq_inplace_concat */
    0                      /* sq_inplace_repeat */
};

PyTypeObject dirstateTupleType = {
    PyVarObject_HEAD_INIT(NULL, 0)      /* header */
    "dirstate_tuple",                   /* tp_name */
    sizeof(dirstateTupleObject),        /* tp_basicsize */
    0,                                  /* tp_itemsize */
    (destructor)dirstate_tuple_dealloc, /* tp_dealloc */
    0,                                  /* tp_print */
    0,                                  /* tp_getattr */
    0,                                  /* tp_setattr */
    0,                                  /* tp_compare */
    0,                                  /* tp_repr */
    0,                                  /* tp_as_number */
    &dirstate_tuple_sq,                 /* 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,                 /* tp_flags */
    "dirstate tuple",                   /* 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 */
    0,                                  /* 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 */
    dirstate_tuple_new,                 /* tp_new */
};

static PyObject *parse_dirstate(PyObject *self, PyObject *args)
{
	PyObject *dmap, *cmap, *parents = NULL, *ret = NULL;
	PyObject *fname = NULL, *cname = NULL, *entry = NULL;
	char state, *cur, *str, *cpos;
	int mode, size, mtime;
	unsigned int flen, len, pos = 40;
	int readlen;

	if (!PyArg_ParseTuple(args, "O!O!s#:parse_dirstate", &PyDict_Type,
	                      &dmap, &PyDict_Type, &cmap, &str, &readlen))
		goto quit;

	len = readlen;

	/* read parents */
	if (len < 40) {
		PyErr_SetString(PyExc_ValueError,
		                "too little data for parents");
		goto quit;
	}

	parents = Py_BuildValue("s#s#", str, 20, str + 20, 20);
	if (!parents)
		goto quit;

	/* read filenames */
	while (pos >= 40 && pos < len) {
		if (pos + 17 > len) {
			PyErr_SetString(PyExc_ValueError,
			                "overflow in dirstate");
			goto quit;
		}
		cur = str + pos;
		/* unpack header */
		state = *cur;
		mode = getbe32(cur + 1);
		size = getbe32(cur + 5);
		mtime = getbe32(cur + 9);
		flen = getbe32(cur + 13);
		pos += 17;
		cur += 17;
		if (flen > len - pos) {
			PyErr_SetString(PyExc_ValueError,
			                "overflow in dirstate");
			goto quit;
		}

		entry =
		    (PyObject *)make_dirstate_tuple(state, mode, size, mtime);
		cpos = memchr(cur, 0, flen);
		if (cpos) {
			fname = PyBytes_FromStringAndSize(cur, cpos - cur);
			cname = PyBytes_FromStringAndSize(
			    cpos + 1, flen - (cpos - cur) - 1);
			if (!fname || !cname ||
			    PyDict_SetItem(cmap, fname, cname) == -1 ||
			    PyDict_SetItem(dmap, fname, entry) == -1)
				goto quit;
			Py_DECREF(cname);
		} else {
			fname = PyBytes_FromStringAndSize(cur, flen);
			if (!fname || PyDict_SetItem(dmap, fname, entry) == -1)
				goto quit;
		}
		Py_DECREF(fname);
		Py_DECREF(entry);
		fname = cname = entry = NULL;
		pos += flen;
	}

	ret = parents;
	Py_INCREF(ret);
quit:
	Py_XDECREF(fname);
	Py_XDECREF(cname);
	Py_XDECREF(entry);
	Py_XDECREF(parents);
	return ret;
}

/*
 * Build a set of non-normal and other parent entries from the dirstate dmap
 */
static PyObject *nonnormalotherparententries(PyObject *self, PyObject *args)
{
	PyObject *dmap, *fname, *v;
	PyObject *nonnset = NULL, *otherpset = NULL, *result = NULL;
	Py_ssize_t pos;

	if (!PyArg_ParseTuple(args, "O!:nonnormalentries", &PyDict_Type, &dmap))
		goto bail;

	nonnset = PySet_New(NULL);
	if (nonnset == NULL)
		goto bail;

	otherpset = PySet_New(NULL);
	if (otherpset == NULL)
		goto bail;

	pos = 0;
	while (PyDict_Next(dmap, &pos, &fname, &v)) {
		dirstateTupleObject *t;
		if (!dirstate_tuple_check(v)) {
			PyErr_SetString(PyExc_TypeError,
			                "expected a dirstate tuple");
			goto bail;
		}
		t = (dirstateTupleObject *)v;

		if (t->state == 'n' && t->size == -2) {
			if (PySet_Add(otherpset, fname) == -1) {
				goto bail;
			}
		}

		if (t->state == 'n' && t->mtime != -1)
			continue;
		if (PySet_Add(nonnset, fname) == -1)
			goto bail;
	}

	result = Py_BuildValue("(OO)", nonnset, otherpset);
	if (result == NULL)
		goto bail;
	Py_DECREF(nonnset);
	Py_DECREF(otherpset);
	return result;
bail:
	Py_XDECREF(nonnset);
	Py_XDECREF(otherpset);
	Py_XDECREF(result);
	return NULL;
}

/*
 * Efficiently pack a dirstate object into its on-disk format.
 */
static PyObject *pack_dirstate(PyObject *self, PyObject *args)
{
	PyObject *packobj = NULL;
	PyObject *map, *copymap, *pl, *mtime_unset = NULL;
	Py_ssize_t nbytes, pos, l;
	PyObject *k, *v = NULL, *pn;
	char *p, *s;
	int now;

	if (!PyArg_ParseTuple(args, "O!O!Oi:pack_dirstate", &PyDict_Type, &map,
	                      &PyDict_Type, &copymap, &pl, &now))
		return NULL;

	if (!PySequence_Check(pl) || PySequence_Size(pl) != 2) {
		PyErr_SetString(PyExc_TypeError, "expected 2-element sequence");
		return NULL;
	}

	/* Figure out how much we need to allocate. */
	for (nbytes = 40, pos = 0; PyDict_Next(map, &pos, &k, &v);) {
		PyObject *c;
		if (!PyBytes_Check(k)) {
			PyErr_SetString(PyExc_TypeError, "expected string key");
			goto bail;
		}
		nbytes += PyBytes_GET_SIZE(k) + 17;
		c = PyDict_GetItem(copymap, k);
		if (c) {
			if (!PyBytes_Check(c)) {
				PyErr_SetString(PyExc_TypeError,
				                "expected string key");
				goto bail;
			}
			nbytes += PyBytes_GET_SIZE(c) + 1;
		}
	}

	packobj = PyBytes_FromStringAndSize(NULL, nbytes);
	if (packobj == NULL)
		goto bail;

	p = PyBytes_AS_STRING(packobj);

	pn = PySequence_ITEM(pl, 0);
	if (PyBytes_AsStringAndSize(pn, &s, &l) == -1 || l != 20) {
		PyErr_SetString(PyExc_TypeError, "expected a 20-byte hash");
		goto bail;
	}
	memcpy(p, s, l);
	p += 20;
	pn = PySequence_ITEM(pl, 1);
	if (PyBytes_AsStringAndSize(pn, &s, &l) == -1 || l != 20) {
		PyErr_SetString(PyExc_TypeError, "expected a 20-byte hash");
		goto bail;
	}
	memcpy(p, s, l);
	p += 20;

	for (pos = 0; PyDict_Next(map, &pos, &k, &v);) {
		dirstateTupleObject *tuple;
		char state;
		int mode, size, mtime;
		Py_ssize_t len, l;
		PyObject *o;
		char *t;

		if (!dirstate_tuple_check(v)) {
			PyErr_SetString(PyExc_TypeError,
			                "expected a dirstate tuple");
			goto bail;
		}
		tuple = (dirstateTupleObject *)v;

		state = tuple->state;
		mode = tuple->mode;
		size = tuple->size;
		mtime = tuple->mtime;
		if (state == 'n' && mtime == now) {
			/* See pure/parsers.py:pack_dirstate for why we do
			 * this. */
			mtime = -1;
			mtime_unset = (PyObject *)make_dirstate_tuple(
			    state, mode, size, mtime);
			if (!mtime_unset)
				goto bail;
			if (PyDict_SetItem(map, k, mtime_unset) == -1)
				goto bail;
			Py_DECREF(mtime_unset);
			mtime_unset = NULL;
		}
		*p++ = state;
		putbe32((uint32_t)mode, p);
		putbe32((uint32_t)size, p + 4);
		putbe32((uint32_t)mtime, p + 8);
		t = p + 12;
		p += 16;
		len = PyBytes_GET_SIZE(k);
		memcpy(p, PyBytes_AS_STRING(k), len);
		p += len;
		o = PyDict_GetItem(copymap, k);
		if (o) {
			*p++ = '\0';
			l = PyBytes_GET_SIZE(o);
			memcpy(p, PyBytes_AS_STRING(o), l);
			p += l;
			len += l + 1;
		}
		putbe32((uint32_t)len, t);
	}

	pos = p - PyBytes_AS_STRING(packobj);
	if (pos != nbytes) {
		PyErr_Format(PyExc_SystemError, "bad dirstate size: %ld != %ld",
		             (long)pos, (long)nbytes);
		goto bail;
	}

	return packobj;
bail:
	Py_XDECREF(mtime_unset);
	Py_XDECREF(packobj);
	Py_XDECREF(v);
	return NULL;
}

#define BUMPED_FIX 1
#define USING_SHA_256 2
#define FM1_HEADER_SIZE (4 + 8 + 2 + 2 + 1 + 1 + 1)

static PyObject *readshas(const char *source, unsigned char num,
                          Py_ssize_t hashwidth)
{
	int i;
	PyObject *list = PyTuple_New(num);
	if (list == NULL) {
		return NULL;
	}
	for (i = 0; i < num; i++) {
		PyObject *hash = PyBytes_FromStringAndSize(source, hashwidth);
		if (hash == NULL) {
			Py_DECREF(list);
			return NULL;
		}
		PyTuple_SET_ITEM(list, i, hash);
		source += hashwidth;
	}
	return list;
}

static PyObject *fm1readmarker(const char *databegin, const char *dataend,
                               uint32_t *msize)
{
	const char *data = databegin;
	const char *meta;

	double mtime;
	int16_t tz;
	uint16_t flags;
	unsigned char nsuccs, nparents, nmetadata;
	Py_ssize_t hashwidth = 20;

	PyObject *prec = NULL, *parents = NULL, *succs = NULL;
	PyObject *metadata = NULL, *ret = NULL;
	int i;

	if (data + FM1_HEADER_SIZE > dataend) {
		goto overflow;
	}

	*msize = getbe32(data);
	data += 4;
	mtime = getbefloat64(data);
	data += 8;
	tz = getbeint16(data);
	data += 2;
	flags = getbeuint16(data);
	data += 2;

	if (flags & USING_SHA_256) {
		hashwidth = 32;
	}

	nsuccs = (unsigned char)(*data++);
	nparents = (unsigned char)(*data++);
	nmetadata = (unsigned char)(*data++);

	if (databegin + *msize > dataend) {
		goto overflow;
	}
	dataend = databegin + *msize; /* narrow down to marker size */

	if (data + hashwidth > dataend) {
		goto overflow;
	}
	prec = PyBytes_FromStringAndSize(data, hashwidth);
	data += hashwidth;
	if (prec == NULL) {
		goto bail;
	}

	if (data + nsuccs * hashwidth > dataend) {
		goto overflow;
	}
	succs = readshas(data, nsuccs, hashwidth);
	if (succs == NULL) {
		goto bail;
	}
	data += nsuccs * hashwidth;

	if (nparents == 1 || nparents == 2) {
		if (data + nparents * hashwidth > dataend) {
			goto overflow;
		}
		parents = readshas(data, nparents, hashwidth);
		if (parents == NULL) {
			goto bail;
		}
		data += nparents * hashwidth;
	} else {
		parents = Py_None;
		Py_INCREF(parents);
	}

	if (data + 2 * nmetadata > dataend) {
		goto overflow;
	}
	meta = data + (2 * nmetadata);
	metadata = PyTuple_New(nmetadata);
	if (metadata == NULL) {
		goto bail;
	}
	for (i = 0; i < nmetadata; i++) {
		PyObject *tmp, *left = NULL, *right = NULL;
		Py_ssize_t leftsize = (unsigned char)(*data++);
		Py_ssize_t rightsize = (unsigned char)(*data++);
		if (meta + leftsize + rightsize > dataend) {
			goto overflow;
		}
		left = PyBytes_FromStringAndSize(meta, leftsize);
		meta += leftsize;
		right = PyBytes_FromStringAndSize(meta, rightsize);
		meta += rightsize;
		tmp = PyTuple_New(2);
		if (!left || !right || !tmp) {
			Py_XDECREF(left);
			Py_XDECREF(right);
			Py_XDECREF(tmp);
			goto bail;
		}
		PyTuple_SET_ITEM(tmp, 0, left);
		PyTuple_SET_ITEM(tmp, 1, right);
		PyTuple_SET_ITEM(metadata, i, tmp);
	}
	ret = Py_BuildValue("(OOHO(di)O)", prec, succs, flags, metadata, mtime,
	                    (int)tz * 60, parents);
	goto bail; /* return successfully */

overflow:
	PyErr_SetString(PyExc_ValueError, "overflow in obsstore");
bail:
	Py_XDECREF(prec);
	Py_XDECREF(succs);
	Py_XDECREF(metadata);
	Py_XDECREF(parents);
	return ret;
}

static PyObject *fm1readmarkers(PyObject *self, PyObject *args)
{
	const char *data, *dataend;
	int datalen;
	Py_ssize_t offset, stop;
	PyObject *markers = NULL;

	if (!PyArg_ParseTuple(args, "s#nn", &data, &datalen, &offset, &stop)) {
		return NULL;
	}
	dataend = data + datalen;
	data += offset;
	markers = PyList_New(0);
	if (!markers) {
		return NULL;
	}
	while (offset < stop) {
		uint32_t msize;
		int error;
		PyObject *record = fm1readmarker(data, dataend, &msize);
		if (!record) {
			goto bail;
		}
		error = PyList_Append(markers, record);
		Py_DECREF(record);
		if (error) {
			goto bail;
		}
		data += msize;
		offset += msize;
	}
	return markers;
bail:
	Py_DECREF(markers);
	return NULL;
}

static char parsers_doc[] = "Efficient content parsing.";

PyObject *encodedir(PyObject *self, PyObject *args);
PyObject *pathencode(PyObject *self, PyObject *args);
PyObject *lowerencode(PyObject *self, PyObject *args);
PyObject *parse_index2(PyObject *self, PyObject *args);

static PyMethodDef methods[] = {
    {"pack_dirstate", pack_dirstate, METH_VARARGS, "pack a dirstate\n"},
    {"nonnormalotherparententries", nonnormalotherparententries, METH_VARARGS,
     "create a set containing non-normal and other parent entries of given "
     "dirstate\n"},
    {"parse_manifest", parse_manifest, METH_VARARGS, "parse a manifest\n"},
    {"parse_dirstate", parse_dirstate, METH_VARARGS, "parse a dirstate\n"},
    {"parse_index2", parse_index2, METH_VARARGS, "parse a revlog index\n"},
    {"isasciistr", isasciistr, METH_VARARGS, "check if an ASCII string\n"},
    {"asciilower", asciilower, METH_VARARGS, "lowercase an ASCII string\n"},
    {"asciiupper", asciiupper, METH_VARARGS, "uppercase an ASCII string\n"},
    {"dict_new_presized", dict_new_presized, METH_VARARGS,
     "construct a dict with an expected size\n"},
    {"make_file_foldmap", make_file_foldmap, METH_VARARGS,
     "make file foldmap\n"},
    {"jsonescapeu8fast", jsonescapeu8fast, METH_VARARGS,
     "escape a UTF-8 byte string to JSON (fast path)\n"},
    {"encodedir", encodedir, METH_VARARGS, "encodedir a path\n"},
    {"pathencode", pathencode, METH_VARARGS, "fncache-encode a path\n"},
    {"lowerencode", lowerencode, METH_VARARGS, "lower-encode a path\n"},
    {"fm1readmarkers", fm1readmarkers, METH_VARARGS,
     "parse v1 obsolete markers\n"},
    {NULL, NULL}};

void dirs_module_init(PyObject *mod);
void manifest_module_init(PyObject *mod);
void revlog_module_init(PyObject *mod);

static const int version = 4;

static void module_init(PyObject *mod)
{
	PyModule_AddIntConstant(mod, "version", version);

	/* This module constant has two purposes.  First, it lets us unit test
	 * the ImportError raised without hard-coding any error text.  This
	 * means we can change the text in the future without breaking tests,
	 * even across changesets without a recompile.  Second, its presence
	 * can be used to determine whether the version-checking logic is
	 * present, which also helps in testing across changesets without a
	 * recompile.  Note that this means the pure-Python version of parsers
	 * should not have this module constant. */
	PyModule_AddStringConstant(mod, "versionerrortext", versionerrortext);

	dirs_module_init(mod);
	manifest_module_init(mod);
	revlog_module_init(mod);

	if (PyType_Ready(&dirstateTupleType) < 0)
		return;
	Py_INCREF(&dirstateTupleType);
	PyModule_AddObject(mod, "dirstatetuple",
	                   (PyObject *)&dirstateTupleType);
}

static int check_python_version(void)
{
	PyObject *sys = PyImport_ImportModule("sys"), *ver;
	long hexversion;
	if (!sys)
		return -1;
	ver = PyObject_GetAttrString(sys, "hexversion");
	Py_DECREF(sys);
	if (!ver)
		return -1;
	hexversion = PyInt_AsLong(ver);
	Py_DECREF(ver);
	/* sys.hexversion is a 32-bit number by default, so the -1 case
	 * should only occur in unusual circumstances (e.g. if sys.hexversion
	 * is manually set to an invalid value). */
	if ((hexversion == -1) || (hexversion >> 16 != PY_VERSION_HEX >> 16)) {
		PyErr_Format(PyExc_ImportError,
		             "%s: The Mercurial extension "
		             "modules were compiled with Python " PY_VERSION
		             ", but "
		             "Mercurial is currently using Python with "
		             "sys.hexversion=%ld: "
		             "Python %s\n at: %s",
		             versionerrortext, hexversion, Py_GetVersion(),
		             Py_GetProgramFullPath());
		return -1;
	}
	return 0;
}

#ifdef IS_PY3K
static struct PyModuleDef parsers_module = {PyModuleDef_HEAD_INIT, "parsers",
                                            parsers_doc, -1, methods};

PyMODINIT_FUNC PyInit_parsers(void)
{
	PyObject *mod;

	if (check_python_version() == -1)
		return NULL;
	mod = PyModule_Create(&parsers_module);
	module_init(mod);
	return mod;
}
#else
PyMODINIT_FUNC initparsers(void)
{
	PyObject *mod;

	if (check_python_version() == -1)
		return;
	mod = Py_InitModule3("parsers", methods, parsers_doc);
	module_init(mod);
}
#endif