comparison mercurial/cext/revlog.c @ 38846:f738c502e43b

index: store nullrev as -1 in nodetree

Nothing important, it just seems more natural to not map nullrev to
INT_MAX. We just need to change the revision encoding a little to make
space for the -1.

Differential Revision: https://phab.mercurial-scm.org/D4005

38845:f9fc59ea3135

/*
 * A base-16 trie for fast node->rev mapping.
 *
 * Positive value is index of the next node in the trie
 * Negative value is a leaf: -(rev + 1)
 * Zero is empty
 */
typedef struct {
	int children[16];
} nodetree;

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 == INT_MAX)
		return nullid;

	if (pos >= length)
		return NULL;

		if (v < 0) {
			const char *n;
			Py_ssize_t i;

			v = -(v + 1);
			n = index_node(self, v);
			if (n == NULL)
				return -2;
			for (i = level; i < maxlevel; i++)
				if (getnybble(node, i) != nt_level(n, i))

		n = &self->nt[off];
		v = n->children[k];

		if (v == 0) {
			n->children[k] = -rev - 1;
			return 0;
		}
		if (v < 0) {
			const char *oldnode = index_node_existing(self, -(v + 1));
			int noff;

			if (oldnode == NULL)
				return -1;
			if (!memcmp(oldnode, node, 20)) {
				n->children[k] = -rev - 1;
				return 0;
			}
			noff = nt_new(self);
			if (noff == -1)
				return -1;

	return -1;
}

static int nt_delete_node(indexObject *self, const char *node)
{
	/* rev==-1 happens to get encoded as 0, which is interpreted as not set */
	return nt_insert(self, node, -1);
}

static int nt_init(indexObject *self)
{
	if (self->nt == NULL) {

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

		nodetree *n = &self->nt[off];
		k = nt_level(node, level);
		v = n->children[k];
		if (v < 0) {
			const char *n;
			v = -(v + 1);
			n = index_node_existing(self, v);
			if (n == NULL)
				return -3;
			if (memcmp(node, n, 20) != 0)
				/*

38846:f738c502e43b

/*
 * A base-16 trie for fast node->rev mapping.
 *
 * Positive value is index of the next node in the trie
 * Negative value is a leaf: -(rev + 2)
 * Zero is empty
 */
typedef struct {
	int children[16];
} nodetree;

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 (pos >= length)
		return NULL;

		if (v < 0) {
			const char *n;
			Py_ssize_t i;

			v = -(v + 2);
			n = index_node(self, v);
			if (n == NULL)
				return -2;
			for (i = level; i < maxlevel; i++)
				if (getnybble(node, i) != nt_level(n, i))

		n = &self->nt[off];
		v = n->children[k];

		if (v == 0) {
			n->children[k] = -rev - 2;
			return 0;
		}
		if (v < 0) {
			const char *oldnode = index_node_existing(self, -(v + 2));
			int noff;

			if (oldnode == NULL)
				return -1;
			if (!memcmp(oldnode, node, 20)) {
				n->children[k] = -rev - 2;
				return 0;
			}
			noff = nt_new(self);
			if (noff == -1)
				return -1;

	return -1;
}

static int nt_delete_node(indexObject *self, const char *node)
{
	/* rev==-2 happens to get encoded as 0, which is interpreted as not set */
	return nt_insert(self, node, -2);
}

static int nt_init(indexObject *self)
{
	if (self->nt == NULL) {

		}
		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;
			return -1;
		}
	}

		nodetree *n = &self->nt[off];
		k = nt_level(node, level);
		v = n->children[k];
		if (v < 0) {
			const char *n;
			v = -(v + 2);
			n = index_node_existing(self, v);
			if (n == NULL)
				return -3;
			if (memcmp(node, n, 20) != 0)
				/*