implement hcreate_r, hdestroy_r and hsearch_r

the size and alignment of struct hsearch_data are matched to the glibc
definition for binary compatibility. the members of the structure do
not match, which should not be a problem as long as applications
correctly treat the structure as opaque.

unlike the glibc implementation, this version of hcreate_r does not
require the caller to zero-fill the structure before use.

diff --git a/include/search.h b/include/search.h
index 27f6107200d66347f58e2c0addf27228ccc7db30..02e407e3c2aba21b6fe4d015c6430c3155c3db69 100644 (file)
--- a/include/search.h
+++ b/include/search.h
@@ -22,6 +22,18 @@ 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 *);
 

diff --git a/src/search/hsearch.c b/src/search/hsearch.c
index 6fe5ced004e1e717e7c5994b9e470711369cc862..88edb2634b533853ddf9356f83e804689f83e18a 100644 (file)
--- a/src/search/hsearch.c
+++ b/src/search/hsearch.c
@@ -1,6 +1,8 @@
+#define _GNU_SOURCE
 #include <stdlib.h>
 #include <string.h>
 #include <search.h>
+#include "libc.h"
 
 /*
 open addressing hash table with 2^n table size
@@ -19,9 +21,17 @@ struct elem {
        size_t hash;
 };
 
-static size_t mask;
-static size_t used;
-static struct elem *tab;
+struct __tab {
+       struct elem *elems;
+       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)
 {
@@ -33,29 +43,29 @@ static size_t keyhash(char *k)
        return h;
 }
 
-static int resize(size_t nel)
+static int resize(size_t nel, struct hsearch_data *htab)
 {
        size_t newsize;
        size_t i, j;
        struct elem *e, *newe;
-       struct elem *oldtab = tab;
-       struct elem *oldend = tab + mask + 1;
+       struct elem *oldtab = htab->__tab->elems;
+       struct elem *oldend = htab->__tab->elems + htab->__tab->mask + 1;
 
        if (nel > MAXSIZE)
                nel = MAXSIZE;
        for (newsize = MINSIZE; newsize < nel; newsize *= 2);
-       tab = calloc(newsize, sizeof *tab);
-       if (!tab) {
-               tab = oldtab;
+       htab->__tab->elems = calloc(newsize, sizeof *htab->__tab->elems);
+       if (!htab->__tab->elems) {
+               htab->__tab->elems = oldtab;
                return 0;
        }
-       mask = newsize - 1;
+       htab->__tab->mask = newsize - 1;
        if (!oldtab)
                return 1;
        for (e = oldtab; e < oldend; e++)
                if (e->item.key) {
                        for (i=e->hash,j=1; ; i+=j++) {
-                               newe = tab + (i & mask);
+                               newe = htab->__tab->elems + (i & htab->__tab->mask);
                                if (!newe->item.key)
                                        break;
                        }
@@ -67,27 +77,21 @@ static int resize(size_t nel)
 
 int hcreate(size_t nel)
 {
-       mask = 0;
-       used = 0;
-       tab = 0;
-       return resize(nel);
+       return __hcreate_r(nel, &htab);
 }
 
 void hdestroy(void)
 {
-       free(tab);
-       tab = 0;
-       mask = 0;
-       used = 0;
+       __hdestroy_r(&htab);
 }
 
-static struct elem *lookup(char *key, size_t hash)
+static struct elem *lookup(char *key, size_t hash, struct hsearch_data *htab)
 {
        size_t i, j;
        struct elem *e;
 
        for (i=hash,j=1; ; i+=j++) {
-               e = tab + (i & mask);
+               e = htab->__tab->elems + (i & htab->__tab->mask);
                if (!e->item.key ||
                    (e->hash==hash && strcmp(e->item.key, key)==0))
                        break;
@@ -96,23 +100,62 @@ static struct elem *lookup(char *key, size_t hash)
 }
 
 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->elems);
+       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);
-       struct elem *e = lookup(item.key, hash);
+       struct elem *e = lookup(item.key, hash, htab);
 
-       if (e->item.key)
-               return &e->item;
-       if (action == FIND)
+       if (e->item.key) {
+               *retval = &e->item;
+               return 1;
+       }
+       if (action == FIND) {
+               *retval = 0;
                return 0;
+       }
        e->item = item;
        e->hash = hash;
-       if (++used > mask - mask/4) {
-               if (!resize(2*used)) {
-                       used--;
+       if (++htab->__tab->used > htab->__tab->mask - htab->__tab->mask/4) {
+               if (!resize(2*htab->__tab->used, htab)) {
+                       htab->__tab->used--;
                        e->item.key = 0;
+                       *retval = 0;
                        return 0;
                }
-               e = lookup(item.key, hash);
+               e = lookup(item.key, hash, htab);
        }
-       return &e->item;
+       *retval = &e->item;
+       return 1;
 }
+weak_alias(__hsearch_r, hsearch_r);