comparison mercurial/cext/revlog.c @ 38851:781b2720d2ac

index: don't include nullid in len()

I suspect the reason the nullid is in the index in the last position
is that it lets index[i] for regular revision number, even when index
was just a regular Python list. An alternative solution would have
been to reserve revision number 0 for the null revision. I don't know
why that wasn't done. Now that we have classes backing the index, we
can easily make index[-1] get the nullid without having to put it last
in the list and including it in the len().

This patch just hides the nullid -- it will still be accessible at
index[len(index)].

I realize that this will be annoying when checking out across this
commit for debugging (including bisection).

Differential Revision: https://phab.mercurial-scm.org/D4022

38850:6104b203bec8

} indexObject;

static Py_ssize_t index_length(const indexObject *self)
{
	if (self->added == NULL)
		return self->length;
	return self->length + PyList_GET_SIZE(self->added);
}

static PyObject *nullentry;
static const char nullid[20];

{
	uint64_t offset_flags;
	int comp_len, uncomp_len, base_rev, link_rev, parent_1, parent_2;
	const char *c_node_id;
	const char *data;
	Py_ssize_t length = index_length(self);
	PyObject *entry;

	if (pos == -1 || pos == length - 1) {
		Py_INCREF(nullentry);
		return nullentry;

/*
 * Return the 20-byte SHA of the node corresponding to the given rev.
 */
static const char *index_node(indexObject *self, Py_ssize_t pos)
{
	Py_ssize_t length = index_length(self);
	const char *data;

	if (pos == length - 1 || pos == -1)
		return nullid;

	}

	if (node_check(PyTuple_GET_ITEM(obj, 7), &node) == -1)
		return NULL;

	len = index_length(self);

	if (self->added == NULL) {
		self->added = PyList_New(0);
		if (self->added == NULL)
			return NULL;

static Py_ssize_t add_roots_get_min(indexObject *self, PyObject *list,
                                    Py_ssize_t marker, char *phases)
{
	PyObject *iter = NULL;
	PyObject *iter_item = NULL;
	Py_ssize_t min_idx = index_length(self) + 1;
	long iter_item_long;

	if (PyList_GET_SIZE(list) != 0) {
		iter = PyObject_GetIter(list);
		if (iter == NULL)

	PyObject *heads = NULL;
	PyObject *roots = NULL;
	PyObject *reachable = NULL;

	PyObject *val;
	Py_ssize_t len = index_length(self) - 1;
	long revnum;
	Py_ssize_t k;
	Py_ssize_t i;
	Py_ssize_t l;
	int r;

	PyObject *phasessize = NULL;
	PyObject *phaseroots = NULL;
	PyObject *phaseset = NULL;
	PyObject *phasessetlist = NULL;
	PyObject *rev = NULL;
	Py_ssize_t len = index_length(self) - 1;
	Py_ssize_t numphase = 0;
	Py_ssize_t minrevallphases = 0;
	Py_ssize_t minrevphase = 0;
	Py_ssize_t i = 0;
	char *phases = NULL;

				"filteredrevs has no attribute __contains__");
			goto bail;
		}
	}

	len = index_length(self) - 1;
	heads = PyList_New(0);
	if (heads == NULL)
		goto bail;
	if (len == 0) {
		PyObject *nullid = PyInt_FromLong(-1);

	int rev, generaldelta;
	PyObject *stoparg;
	int stoprev, iterrev, baserev = -1;
	int stopped;
	PyObject *chain = NULL, *result = NULL;
	const Py_ssize_t length = index_length(self);

	if (!PyArg_ParseTuple(args, "iOi", &rev, &stoparg, &generaldelta)) {
		return NULL;
	}

		if (self->nt == NULL) {
			PyErr_NoMemory();
			return -1;
		}
		self->ntlength = 1;
		self->ntrev = (int)index_length(self) - 1;
		self->ntlookups = 1;
		self->ntmisses = 0;
		if (nt_insert(self, nullid, -1) == -1) {
			free(self->nt);
			self->nt = NULL;

{
	char *node;

	if (PyInt_Check(value)) {
		long rev = PyInt_AS_LONG(value);
		return rev >= -1 && rev < index_length(self);
	}

	if (node_check(value, &node) == -1)
		return -1;

	argcount = PySequence_Length(args);
	revs = PyMem_Malloc(argcount * sizeof(*revs));
	if (argcount > 0 && revs == NULL)
		return PyErr_NoMemory();
	len = index_length(self) - 1;

	for (i = 0; i < argcount; i++) {
		static const int capacity = 24;
		PyObject *obj = PySequence_GetItem(args, i);
		bitmask x;

 * range, but exclude the sentinel nullid entry.
 */
static int index_slice_del(indexObject *self, PyObject *item)
{
	Py_ssize_t start, stop, step, slicelength;
	Py_ssize_t length = index_length(self);
	int ret = 0;

/* Argument changed from PySliceObject* to PyObject* in Python 3. */
#ifdef IS_PY3K
	if (PySlice_GetIndicesEx(item, length,

38851:781b2720d2ac

} indexObject;

static Py_ssize_t index_length(const indexObject *self)
{
	if (self->added == NULL)
		return self->length - 1;
	return self->length + PyList_GET_SIZE(self->added) - 1;
}

static PyObject *nullentry;
static const char nullid[20];

{
	uint64_t offset_flags;
	int comp_len, uncomp_len, base_rev, link_rev, parent_1, parent_2;
	const char *c_node_id;
	const char *data;
	Py_ssize_t length = index_length(self) + 1;
	PyObject *entry;

	if (pos == -1 || pos == length - 1) {
		Py_INCREF(nullentry);
		return nullentry;

/*
 * Return the 20-byte SHA of the node corresponding to the given rev.
 */
static const char *index_node(indexObject *self, Py_ssize_t pos)
{
	Py_ssize_t length = index_length(self) + 1;
	const char *data;

	if (pos == length - 1 || pos == -1)
		return nullid;

	}

	if (node_check(PyTuple_GET_ITEM(obj, 7), &node) == -1)
		return NULL;

	len = index_length(self) + 1;

	if (self->added == NULL) {
		self->added = PyList_New(0);
		if (self->added == NULL)
			return NULL;

static Py_ssize_t add_roots_get_min(indexObject *self, PyObject *list,
                                    Py_ssize_t marker, char *phases)
{
	PyObject *iter = NULL;
	PyObject *iter_item = NULL;
	Py_ssize_t min_idx = index_length(self) + 2;
	long iter_item_long;

	if (PyList_GET_SIZE(list) != 0) {
		iter = PyObject_GetIter(list);
		if (iter == NULL)

	PyObject *heads = NULL;
	PyObject *roots = NULL;
	PyObject *reachable = NULL;

	PyObject *val;
	Py_ssize_t len = index_length(self);
	long revnum;
	Py_ssize_t k;
	Py_ssize_t i;
	Py_ssize_t l;
	int r;

	PyObject *phasessize = NULL;
	PyObject *phaseroots = NULL;
	PyObject *phaseset = NULL;
	PyObject *phasessetlist = NULL;
	PyObject *rev = NULL;
	Py_ssize_t len = index_length(self);
	Py_ssize_t numphase = 0;
	Py_ssize_t minrevallphases = 0;
	Py_ssize_t minrevphase = 0;
	Py_ssize_t i = 0;
	char *phases = NULL;

				"filteredrevs has no attribute __contains__");
			goto bail;
		}
	}

	len = index_length(self);
	heads = PyList_New(0);
	if (heads == NULL)
		goto bail;
	if (len == 0) {
		PyObject *nullid = PyInt_FromLong(-1);

	int rev, generaldelta;
	PyObject *stoparg;
	int stoprev, iterrev, baserev = -1;
	int stopped;
	PyObject *chain = NULL, *result = NULL;
	const Py_ssize_t length = index_length(self) + 1;

	if (!PyArg_ParseTuple(args, "iOi", &rev, &stoparg, &generaldelta)) {
		return NULL;
	}

		if (self->nt == NULL) {
			PyErr_NoMemory();
			return -1;
		}
		self->ntlength = 1;
		self->ntrev = (int)index_length(self);
		self->ntlookups = 1;
		self->ntmisses = 0;
		if (nt_insert(self, nullid, -1) == -1) {
			free(self->nt);
			self->nt = NULL;

{
	char *node;

	if (PyInt_Check(value)) {
		long rev = PyInt_AS_LONG(value);
		return rev >= -1 && rev < index_length(self) + 1;
	}

	if (node_check(value, &node) == -1)
		return -1;

	argcount = PySequence_Length(args);
	revs = PyMem_Malloc(argcount * sizeof(*revs));
	if (argcount > 0 && revs == NULL)
		return PyErr_NoMemory();
	len = index_length(self);

	for (i = 0; i < argcount; i++) {
		static const int capacity = 24;
		PyObject *obj = PySequence_GetItem(args, i);
		bitmask x;

 * range, but exclude the sentinel nullid entry.
 */
static int index_slice_del(indexObject *self, PyObject *item)
{
	Py_ssize_t start, stop, step, slicelength;
	Py_ssize_t length = index_length(self) + 1;
	int ret = 0;

/* Argument changed from PySliceObject* to PyObject* in Python 3. */
#ifdef IS_PY3K
	if (PySlice_GetIndicesEx(item, length,