added tsearch from musl

https://git.musl-libc.org/cgit/musl/snapshot/musl-1.2.4.tar.gz

third_party/musl/hsearch.c

@@ -0,0 +1,153 @@
+#define _GNU_SOURCE
+#include <stdlib.h>
+#include <string.h>
+#include <search.h>
+
+/*
+open addressing hash table with 2^n table size
+quadratic probing is used in case of hash collision
+tab indices and hash are size_t
+after resize fails with ENOMEM the state of tab is still usable
+
+with the posix api items cannot be iterated and length cannot be queried
+*/
+
+#define MINSIZE 8
+#define MAXSIZE ((size_t)-1/2 + 1)
+
+struct __tab {
+	ENTRY *entries;
+	size_t mask;
+	size_t used;
+};
+
+static struct hsearch_data htab;
+
+static int __hcreate_r(size_t, struct hsearch_data *);
+static void __hdestroy_r(struct hsearch_data *);
+static int __hsearch_r(ENTRY, ACTION, ENTRY **, struct hsearch_data *);
+
+static size_t keyhash(char *k)
+{
+	unsigned char *p = (void *)k;
+	size_t h = 0;
+
+	while (*p)
+		h = 31*h + *p++;
+	return h;
+}
+
+static int resize(size_t nel, struct hsearch_data *htab)
+{
+	size_t newsize;
+	size_t i, j;
+	size_t oldsize = htab->__tab->mask + 1;
+	ENTRY *e, *newe;
+	ENTRY *oldtab = htab->__tab->entries;
+
+	if (nel > MAXSIZE)
+		nel = MAXSIZE;
+	for (newsize = MINSIZE; newsize < nel; newsize *= 2);
+	htab->__tab->entries = calloc(newsize, sizeof *htab->__tab->entries);
+	if (!htab->__tab->entries) {
+		htab->__tab->entries = oldtab;
+		return 0;
+	}
+	htab->__tab->mask = newsize - 1;
+	if (!oldtab)
+		return 1;
+	for (e = oldtab; e < oldtab + oldsize; e++)
+		if (e->key) {
+			for (i=keyhash(e->key),j=1; ; i+=j++) {
+				newe = htab->__tab->entries + (i & htab->__tab->mask);
+				if (!newe->key)
+					break;
+			}
+			*newe = *e;
+		}
+	free(oldtab);
+	return 1;
+}
+
+int hcreate(size_t nel)
+{
+	return __hcreate_r(nel, &htab);
+}
+
+void hdestroy(void)
+{
+	__hdestroy_r(&htab);
+}
+
+static ENTRY *lookup(char *key, size_t hash, struct hsearch_data *htab)
+{
+	size_t i, j;
+	ENTRY *e;
+
+	for (i=hash,j=1; ; i+=j++) {
+		e = htab->__tab->entries + (i & htab->__tab->mask);
+		if (!e->key || strcmp(e->key, key) == 0)
+			break;
+	}
+	return e;
+}
+
+ENTRY *hsearch(ENTRY item, ACTION action)
+{
+	ENTRY *e;
+
+	__hsearch_r(item, action, &e, &htab);
+	return e;
+}
+
+static int __hcreate_r(size_t nel, struct hsearch_data *htab)
+{
+	int r;
+
+	htab->__tab = calloc(1, sizeof *htab->__tab);
+	if (!htab->__tab)
+		return 0;
+	r = resize(nel, htab);
+	if (r == 0) {
+		free(htab->__tab);
+		htab->__tab = 0;
+	}
+	return r;
+}
+weak_alias(__hcreate_r, hcreate_r);
+
+static void __hdestroy_r(struct hsearch_data *htab)
+{
+	if (htab->__tab) free(htab->__tab->entries);
+	free(htab->__tab);
+	htab->__tab = 0;
+}
+weak_alias(__hdestroy_r, hdestroy_r);
+
+static int __hsearch_r(ENTRY item, ACTION action, ENTRY **retval, struct hsearch_data *htab)
+{
+	size_t hash = keyhash(item.key);
+	ENTRY *e = lookup(item.key, hash, htab);
+
+	if (e->key) {
+		*retval = e;
+		return 1;
+	}
+	if (action == FIND) {
+		*retval = 0;
+		return 0;
+	}
+	*e = item;
+	if (++htab->__tab->used > htab->__tab->mask - htab->__tab->mask/4) {
+		if (!resize(2*htab->__tab->used, htab)) {
+			htab->__tab->used--;
+			e->key = 0;
+			*retval = 0;
+			return 0;
+		}
+		e = lookup(item.key, hash, htab);
+	}
+	*retval = e;
+	return 1;
+}
+weak_alias(__hsearch_r, hsearch_r);

third_party/musl/insque.c

@@ -0,0 +1,32 @@
+#include <search.h>
+
+struct node {
+	struct node *next;
+	struct node *prev;
+};
+
+void insque(void *element, void *pred)
+{
+	struct node *e = element;
+	struct node *p = pred;
+
+	if (!p) {
+		e->next = e->prev = 0;
+		return;
+	}
+	e->next = p->next;
+	e->prev = p;
+	p->next = e;
+	if (e->next)
+		e->next->prev = e;
+}
+
+void remque(void *element)
+{
+	struct node *e = element;
+
+	if (e->next)
+		e->next->prev = e->prev;
+	if (e->prev)
+		e->prev->next = e->next;
+}

third_party/musl/lsearch.c

@@ -0,0 +1,31 @@
+#include <search.h>
+#include <string.h>
+
+void *lsearch(const void *key, void *base, size_t *nelp, size_t width,
+	int (*compar)(const void *, const void *))
+{
+	char (*p)[width] = base;
+	size_t n = *nelp;
+	size_t i;
+
+	for (i = 0; i < n; i++)
+		if (compar(key, p[i]) == 0)
+			return p[i];
+	*nelp = n+1;
+	return memcpy(p[n], key, width);
+}
+
+void *lfind(const void *key, const void *base, size_t *nelp,
+	size_t width, int (*compar)(const void *, const void *))
+{
+	char (*p)[width] = (void *)base;
+	size_t n = *nelp;
+	size_t i;
+
+	for (i = 0; i < n; i++)
+		if (compar(key, p[i]) == 0)
+			return p[i];
+	return 0;
+}
+
+

third_party/musl/search.h

@@ -0,0 +1,63 @@
+#ifndef _SEARCH_H
+#define _SEARCH_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <features.h>
+
+#define __NEED_size_t
+#include <bits/alltypes.h>
+
+typedef enum { FIND, ENTER } ACTION;
+typedef enum { preorder, postorder, endorder, leaf } VISIT;
+
+typedef struct entry {
+	char *key;
+	void *data;
+} ENTRY;
+
+int hcreate(size_t);
+void hdestroy(void);
+ENTRY *hsearch(ENTRY, ACTION);
+
+#ifdef _GNU_SOURCE
+struct hsearch_data {
+	struct __tab *__tab;
+	unsigned int __unused1;
+	unsigned int __unused2;
+};
+
+int hcreate_r(size_t, struct hsearch_data *);
+void hdestroy_r(struct hsearch_data *);
+int hsearch_r(ENTRY, ACTION, ENTRY **, struct hsearch_data *);
+#endif
+
+void insque(void *, void *);
+void remque(void *);
+
+void *lsearch(const void *, void *, size_t *, size_t,
+	int (*)(const void *, const void *));
+void *lfind(const void *, const void *, size_t *, size_t,
+	int (*)(const void *, const void *));
+
+void *tdelete(const void *__restrict, void **__restrict, int(*)(const void *, const void *));
+void *tfind(const void *, void *const *, int(*)(const void *, const void *));
+void *tsearch(const void *, void **, int (*)(const void *, const void *));
+void twalk(const void *, void (*)(const void *, VISIT, int));
+
+#ifdef _GNU_SOURCE
+struct qelem {
+	struct qelem *q_forw, *q_back;
+	char q_data[1];
+};
+
+void tdestroy(void *, void (*)(void *));
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

third_party/musl/tdelete.c

@@ -0,0 +1,49 @@
+#include <stdlib.h>
+#include <search.h>
+#include "tsearch.h"
+
+void *tdelete(const void *restrict key, void **restrict rootp,
+	int(*cmp)(const void *, const void *))
+{
+	if (!rootp)
+		return 0;
+
+	void **a[MAXH+1];
+	struct node *n = *rootp;
+	struct node *parent;
+	struct node *child;
+	int i=0;
+	/* *a[0] is an arbitrary non-null pointer that is returned when
+	   the root node is deleted.  */
+	a[i++] = rootp;
+	a[i++] = rootp;
+	for (;;) {
+		if (!n)
+			return 0;
+		int c = cmp(key, n->key);
+		if (!c)
+			break;
+		a[i++] = &n->a[c>0];
+		n = n->a[c>0];
+	}
+	parent = *a[i-2];
+	if (n->a[0]) {
+		/* free the preceding node instead of the deleted one.  */
+		struct node *deleted = n;
+		a[i++] = &n->a[0];
+		n = n->a[0];
+		while (n->a[1]) {
+			a[i++] = &n->a[1];
+			n = n->a[1];
+		}
+		deleted->key = n->key;
+		child = n->a[0];
+	} else {
+		child = n->a[1];
+	}
+	/* freed node has at most one child, move it up and rebalance.  */
+	free(n);
+	*a[--i] = child;
+	while (--i && __tsearch_balance(a[i]));
+	return parent;
+}

third_party/musl/tdestroy.c

@@ -0,0 +1,16 @@
+#define _GNU_SOURCE
+#include <stdlib.h>
+#include <search.h>
+#include "tsearch.h"
+
+void tdestroy(void *root, void (*freekey)(void *))
+{
+	struct node *r = root;
+
+	if (r == 0)
+		return;
+	tdestroy(r->a[0], freekey);
+	tdestroy(r->a[1], freekey);
+	if (freekey) freekey((void *)r->key);
+	free(r);
+}

third_party/musl/tfind.c

@@ -0,0 +1,20 @@
+#include <search.h>
+#include "tsearch.h"
+
+void *tfind(const void *key, void *const *rootp,
+	int(*cmp)(const void *, const void *))
+{
+	if (!rootp)
+		return 0;
+
+	struct node *n = *rootp;
+	for (;;) {
+		if (!n)
+			break;
+		int c = cmp(key, n->key);
+		if (!c)
+			break;
+		n = n->a[c>0];
+	}
+	return n;
+}

third_party/musl/tsearch.c

@@ -0,0 +1,92 @@
+#include <stdlib.h>
+#include <search.h>
+#include "tsearch.h"
+
+static inline int height(struct node *n) { return n ? n->h : 0; }
+
+static int rot(void **p, struct node *x, int dir /* deeper side */)
+{
+	struct node *y = x->a[dir];
+	struct node *z = y->a[!dir];
+	int hx = x->h;
+	int hz = height(z);
+	if (hz > height(y->a[dir])) {
+		/*
+		 *   x
+		 *  / \ dir          z
+		 * A   y            / \
+		 *    / \   -->    x   y
+		 *   z   D        /|   |\
+		 *  / \          A B   C D
+		 * B   C
+		 */
+		x->a[dir] = z->a[!dir];
+		y->a[!dir] = z->a[dir];
+		z->a[!dir] = x;
+		z->a[dir] = y;
+		x->h = hz;
+		y->h = hz;
+		z->h = hz+1;
+	} else {
+		/*
+		 *   x               y
+		 *  / \             / \
+		 * A   y    -->    x   D
+		 *    / \         / \
+		 *   z   D       A   z
+		 */
+		x->a[dir] = z;
+		y->a[!dir] = x;
+		x->h = hz+1;
+		y->h = hz+2;
+		z = y;
+	}
+	*p = z;
+	return z->h - hx;
+}
+
+/* balance *p, return 0 if height is unchanged.  */
+int __tsearch_balance(void **p)
+{
+	struct node *n = *p;
+	int h0 = height(n->a[0]);
+	int h1 = height(n->a[1]);
+	if (h0 - h1 + 1u < 3u) {
+		int old = n->h;
+		n->h = h0<h1 ? h1+1 : h0+1;
+		return n->h - old;
+	}
+	return rot(p, n, h0<h1);
+}
+
+void *tsearch(const void *key, void **rootp,
+	int (*cmp)(const void *, const void *))
+{
+	if (!rootp)
+		return 0;
+
+	void **a[MAXH];
+	struct node *n = *rootp;
+	struct node *r;
+	int i=0;
+	a[i++] = rootp;
+	for (;;) {
+		if (!n)
+			break;
+		int c = cmp(key, n->key);
+		if (!c)
+			return n;
+		a[i++] = &n->a[c>0];
+		n = n->a[c>0];
+	}
+	r = malloc(sizeof *r);
+	if (!r)
+		return 0;
+	r->key = key;
+	r->a[0] = r->a[1] = 0;
+	r->h = 1;
+	/* insert new node, rebalance ancestors.  */
+	*a[--i] = r;
+	while (i && __tsearch_balance(a[--i]));
+	return r;
+}

third_party/musl/tsearch.h

@@ -0,0 +1,13 @@
+#include <search.h>
+#include <features.h>
+
+/* AVL tree height < 1.44*log2(nodes+2)-0.3, MAXH is a safe upper bound.  */
+#define MAXH (sizeof(void*)*8*3/2)
+
+struct node {
+	const void *key;
+	void *a[2];
+	int h;
+};
+
+hidden int __tsearch_balance(void **);

third_party/musl/twalk.c

@@ -0,0 +1,22 @@
+#include <search.h>
+#include "tsearch.h"
+
+static void walk(const struct node *r, void (*action)(const void *, VISIT, int), int d)
+{
+	if (!r)
+		return;
+	if (r->h == 1)
+		action(r, leaf, d);
+	else {
+		action(r, preorder, d);
+		walk(r->a[0], action, d+1);
+		action(r, postorder, d);
+		walk(r->a[1], action, d+1);
+		action(r, endorder, d);
+	}
+}
+
+void twalk(const void *root, void (*action)(const void *, VISIT, int))
+{
+	walk(root, action, 0);
+}