Add a "fork" of musl as //fusl.

fusl/src/search/hsearch.c

+#define _GNU_SOURCE
+#include <stdlib.h>
+#include <string.h>
+#include <search.h>
+#include "libc.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;
+
+int __hcreate_r(size_t, struct hsearch_data *);
+void __hdestroy_r(struct hsearch_data *);
+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;
+        ENTRY *e, *newe;
+        ENTRY *oldtab = htab->__tab->entries;
+        ENTRY *oldend = htab->__tab->entries + htab->__tab->mask + 1;
+
+        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 < oldend; 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;
+}
+
+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);
+
+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);
+
+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);