Add hashtable code from openzap/freetdm to FS core

Makefile.am

@@ -220,7 +220,8 @@ library_include_HEADERS = \
 	libs/libtpl-1.5/src/tpl.h \
 	src/include/switch_limit.h \
 	src/include/switch_odbc.h \
-	src/include/switch_pgsql.h
+	src/include/switch_pgsql.h \
+	src/include/switch_hashtable.h
 
 nodist_libfreeswitch_la_SOURCES = \
 	src/include/switch_frame.h \
@@ -287,6 +288,7 @@ libfreeswitch_la_SOURCES = \
 	src/switch_profile.c \
 	src/switch_json.c \
 	src/switch_curl.c \
+	src/switch_hashtable.c\
 	libs/libtpl-1.5/src/tpl.c \
 	libs/stfu/stfu.c \
 	libs/libteletone/src/libteletone_detect.c \

src/include/private/switch_hashtable_private.h

+/* 
+ * FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
+ *
+ * switch_hashtable_private.h -- Hashtable
+ *
+ */
+
+/* hashtable_private.h -- Copyright (C) 2002, 2004 Christopher Clark <firstname.lastname@cl.cam.ac.uk> */
+
+#ifndef __HASHTABLE_PRIVATE_CWC22_H__
+#define __HASHTABLE_PRIVATE_CWC22_H__
+
+#include "switch_hashtable.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+/*****************************************************************************/
+
+struct entry
+{
+    void *k, *v;
+    unsigned int h;
+	hashtable_flag_t flags;
+    struct entry *next;
+};
+
+struct switch_hashtable_iterator {
+	unsigned int pos;
+	struct entry *e;
+	struct switch_hashtable *h;
+};
+
+struct switch_hashtable {
+    unsigned int tablelength;
+    struct entry **table;
+    unsigned int entrycount;
+    unsigned int loadlimit;
+    unsigned int primeindex;
+    unsigned int (*hashfn) (void *k);
+    int (*eqfn) (void *k1, void *k2);
+	struct switch_hashtable_iterator iterator;
+};
+
+/*****************************************************************************/
+
+/*****************************************************************************/
+static inline unsigned int
+hash(switch_hashtable_t *h, void *k)
+{
+    /* Aim to protect against poor hash functions by adding logic here
+     * - logic taken from java 1.4 hashtable source */
+    unsigned int i = h->hashfn(k);
+    i += ~(i << 9);
+    i ^=  ((i >> 14) | (i << 18)); /* >>> */
+    i +=  (i << 4);
+    i ^=  ((i >> 10) | (i << 22)); /* >>> */
+    return i;
+}
+
+
+/*****************************************************************************/
+/* indexFor */
+static __inline__ unsigned int
+indexFor(unsigned int tablelength, unsigned int hashvalue) {
+    return (hashvalue % tablelength);
+}
+
+/* Only works if tablelength == 2^N */
+/*static inline unsigned int
+  indexFor(unsigned int tablelength, unsigned int hashvalue)
+  {
+  return (hashvalue & (tablelength - 1u));
+  }
+*/
+
+/*****************************************************************************/
+#define freekey(X) free(X)
+/*define freekey(X) ; */
+
+#ifdef __cplusplus
+}
+#endif
+
+/*****************************************************************************/
+
+#endif /* __HASHTABLE_PRIVATE_CWC22_H__*/
+
+/*
+ * Copyright (c) 2002, Christopher Clark
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 
+ * * Neither the name of the original author; nor the names of any contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ * 
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+/* For Emacs:
+ * Local Variables:
+ * mode:c
+ * indent-tabs-mode:t
+ * tab-width:4
+ * c-basic-offset:4
+ * End:
+ * For VIM:
+ * vim:set softtabstop=4 shiftwidth=4 tabstop=4 noet:
+ */

src/include/switch_hashtable.h

+/* 
+ * FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
+ *
+ * switch_hashtable.h -- Hashtable
+ *
+ */
+
+
+/* hashtable.h Copyright (C) 2002 Christopher Clark <firstname.lastname@cl.cam.ac.uk> */
+
+#ifndef __HASHTABLE_CWC22_H__
+#define __HASHTABLE_CWC22_H__
+#ifdef _MSC_VER
+#ifndef __inline__
+#define __inline__ __inline
+#endif
+#endif
+#include "switch.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct switch_hashtable switch_hashtable_t;
+typedef struct switch_hashtable_iterator switch_hashtable_iterator_t;
+
+
+/* Example of use:
+ *
+ *      switch_hashtable_t  *h;
+ *      struct some_key   *k;
+ *      struct some_value *v;
+ *
+ *      static unsigned int         hash_from_key_fn( void *k );
+ *      static int                  keys_equal_fn ( void *key1, void *key2 );
+ *
+ *      h = create_hashtable(16, hash_from_key_fn, keys_equal_fn);
+ *      k = (struct some_key *)     malloc(sizeof(struct some_key));
+ *      v = (struct some_value *)   malloc(sizeof(struct some_value));
+ *
+ *      (initialise k and v to suitable values)
+ * 
+ *      if (! hashtable_insert(h,k,v) )
+ *      {     exit(-1);               }
+ *
+ *      if (NULL == (found = hashtable_search(h,k) ))
+ *      {    printf("not found!");                  }
+ *
+ *      if (NULL == (found = hashtable_remove(h,k) ))
+ *      {    printf("Not found\n");                 }
+ *
+ */
+
+/* Macros may be used to define type-safe(r) hashtable access functions, with
+ * methods specialized to take known key and value types as parameters.
+ * 
+ * Example:
+ *
+ * Insert this at the start of your file:
+ *
+ * DEFINE_HASHTABLE_INSERT(insert_some, struct some_key, struct some_value);
+ * DEFINE_HASHTABLE_SEARCH(search_some, struct some_key, struct some_value);
+ * DEFINE_HASHTABLE_REMOVE(remove_some, struct some_key, struct some_value);
+ *
+ * This defines the functions 'insert_some', 'search_some' and 'remove_some'.
+ * These operate just like hashtable_insert etc., with the same parameters,
+ * but their function signatures have 'struct some_key *' rather than
+ * 'void *', and hence can generate compile time errors if your program is
+ * supplying incorrect data as a key (and similarly for value).
+ *
+ * Note that the hash and key equality functions passed to create_hashtable
+ * still take 'void *' parameters instead of 'some key *'. This shouldn't be
+ * a difficult issue as they're only defined and passed once, and the other
+ * functions will ensure that only valid keys are supplied to them.
+ *
+ * The cost for this checking is increased code size and runtime overhead
+ * - if performance is important, it may be worth switching back to the
+ * unsafe methods once your program has been debugged with the safe methods.
+ * This just requires switching to some simple alternative defines - eg:
+ * #define insert_some hashtable_insert
+ *
+ */
+
+/*****************************************************************************
+ * create_hashtable
+   
+ * @name                    create_hashtable
+ * @param   minsize         minimum initial size of hashtable
+ * @param   hashfunction    function for hashing keys
+ * @param   key_eq_fn       function for determining key equality
+ * @return                  newly created hashtable or NULL on failure
+ */
+
+SWITCH_DECLARE(switch_status_t)
+switch_create_hashtable(switch_hashtable_t **hp, unsigned int minsize,
+                 unsigned int (*hashfunction) (void*),
+                 int (*key_eq_fn) (void*,void*));
+
+/*****************************************************************************
+ * hashtable_insert
+   
+ * @name        hashtable_insert
+ * @param   h   the hashtable to insert into
+ * @param   k   the key - hashtable claims ownership and will free on removal
+ * @param   v   the value - does not claim ownership
+ * @return      non-zero for successful insertion
+ *
+ * This function will cause the table to expand if the insertion would take
+ * the ratio of entries to table size over the maximum load factor.
+ *
+ * This function does not check for repeated insertions with a duplicate key.
+ * The value returned when using a duplicate key is undefined -- when
+ * the hashtable changes size, the order of retrieval of duplicate key
+ * entries is reversed.
+ * If in doubt, remove before insert.
+ */
+
+
+typedef enum {
+	HASHTABLE_FLAG_NONE = 0,
+	HASHTABLE_FLAG_FREE_KEY = (1 << 0),
+	HASHTABLE_FLAG_FREE_VALUE = (1 << 1)
+} hashtable_flag_t;
+
+SWITCH_DECLARE(int)
+switch_hashtable_insert(switch_hashtable_t *h, void *k, void *v, hashtable_flag_t flags);
+
+#define DEFINE_HASHTABLE_INSERT(fnname, keytype, valuetype)		\
+	int fnname (switch_hashtable_t *h, keytype *k, valuetype *v)	\
+	{															\
+		return hashtable_insert(h,k,v);							\
+	}
+
+/*****************************************************************************
+ * hashtable_search
+   
+ * @name        hashtable_search
+ * @param   h   the hashtable to search
+ * @param   k   the key to search for  - does not claim ownership
+ * @return      the value associated with the key, or NULL if none found
+ */
+
+SWITCH_DECLARE(void *)
+switch_hashtable_search(switch_hashtable_t *h, void *k);
+
+#define DEFINE_HASHTABLE_SEARCH(fnname, keytype, valuetype) \
+	valuetype * fnname (switch_hashtable_t *h, keytype *k)	\
+	{														\
+		return (valuetype *) (hashtable_search(h,k));		\
+	}
+
+/*****************************************************************************
+ * hashtable_remove
+   
+ * @name        hashtable_remove
+ * @param   h   the hashtable to remove the item from
+ * @param   k   the key to search for  - does not claim ownership
+ * @return      the value associated with the key, or NULL if none found
+ */
+
+SWITCH_DECLARE(void *) /* returns value */
+switch_hashtable_remove(switch_hashtable_t *h, void *k);
+
+#define DEFINE_HASHTABLE_REMOVE(fnname, keytype, valuetype) \
+	valuetype * fnname (switch_hashtable_t *h, keytype *k)	\
+	{														\
+		return (valuetype *) (hashtable_remove(h,k));		\
+	}
+
+
+/*****************************************************************************
+ * hashtable_count
+   
+ * @name        hashtable_count
+ * @param   h   the hashtable
+ * @return      the number of items stored in the hashtable
+ */
+SWITCH_DECLARE(unsigned int)
+switch_hashtable_count(switch_hashtable_t *h);
+
+
+/*****************************************************************************
+ * hashtable_destroy
+   
+ * @name        hashtable_destroy
+ * @param   h   the hashtable
+ * @param       free_values     whether to call 'free' on the remaining values
+ */
+
+SWITCH_DECLARE(void)
+switch_hashtable_destroy(switch_hashtable_t **h);
+
+SWITCH_DECLARE(switch_hashtable_iterator_t*) switch_hashtable_first(switch_hashtable_t *h);
+SWITCH_DECLARE(switch_hashtable_iterator_t*) switch_hashtable_next(switch_hashtable_iterator_t *i);
+SWITCH_DECLARE(void) switch_hashtable_this(switch_hashtable_iterator_t *i, const void **key, switch_ssize_t *klen, void **val);
+
+static inline int switch_hash_equalkeys(void *k1, void *k2)
+{
+    return strcmp((char *) k1, (char *) k2) ? 0 : 1;
+}
+
+static inline uint32_t switch_hash_default(void *ky)
+{
+	unsigned char *str = (unsigned char *) ky;
+	uint32_t hash = 0;
+    int c;
+	
+	while ((c = *str)) {
+		str++;
+        hash = c + (hash << 6) + (hash << 16) - hash;
+	}
+
+    return hash;
+}
+
+static inline uint32_t switch_hash_default_ci(void *ky)
+{
+	unsigned char *str = (unsigned char *) ky;
+	uint32_t hash = 0;
+    int c;
+	
+	while ((c = switch_tolower(*str))) {
+		str++;
+        hash = c + (hash << 6) + (hash << 16) - hash;
+	}
+
+    return hash;
+}
+
+
+
+
+#ifdef __cplusplus
+} /* extern C */
+#endif
+
+#endif /* __HASHTABLE_CWC22_H__ */
+
+/*
+ * Copyright (c) 2002, Christopher Clark
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 
+ * * Neither the name of the original author; nor the names of any contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ * 
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/* For Emacs:
+ * Local Variables:
+ * mode:c
+ * indent-tabs-mode:t
+ * tab-width:4
+ * c-basic-offset:4
+ * End:
+ * For VIM:
+ * vim:set softtabstop=4 shiftwidth=4 tabstop=4 noet:
+ */

src/switch_hashtable.c

+/*
+ * Copyright (c) 2002, Christopher Clark
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 
+ * * Neither the name of the original author; nor the names of any contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ * 
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "switch.h"
+#include "private/switch_hashtable_private.h"
+
+/*
+  Credit for primes table: Aaron Krowne
+  http://br.endernet.org/~akrowne/
+  http://planetmath.org/encyclopedia/GoodHashTablePrimes.html
+*/
+static const unsigned int primes[] = {
+	53, 97, 193, 389,
+	769, 1543, 3079, 6151,
+	12289, 24593, 49157, 98317,
+	196613, 393241, 786433, 1572869,
+	3145739, 6291469, 12582917, 25165843,
+	50331653, 100663319, 201326611, 402653189,
+	805306457, 1610612741
+};
+const unsigned int prime_table_length = sizeof(primes)/sizeof(primes[0]);
+const float max_load_factor = 0.65f;
+
+/*****************************************************************************/
+SWITCH_DECLARE(switch_status_t)
+switch_create_hashtable(switch_hashtable_t **hp, unsigned int minsize,
+						unsigned int (*hashf) (void*),
+						int (*eqf) (void*,void*))
+{
+    switch_hashtable_t *h;
+    unsigned int pindex, size = primes[0];
+
+    /* Check requested hashtable isn't too large */
+    if (minsize > (1u << 30)) {*hp = NULL; return SWITCH_STATUS_FALSE;}
+    /* Enforce size as prime */
+    for (pindex=0; pindex < prime_table_length; pindex++) {
+        if (primes[pindex] > minsize) { 
+			size = primes[pindex]; 
+			break; 
+		}
+    }
+    h = (switch_hashtable_t *) malloc(sizeof(switch_hashtable_t));
+
+    if (NULL == h) abort(); /*oom*/
+
+    h->table = (struct entry **)malloc(sizeof(struct entry*) * size);
+
+    if (NULL == h->table) abort(); /*oom*/
+
+    memset(h->table, 0, size * sizeof(struct entry *));
+    h->tablelength  = size;
+    h->primeindex   = pindex;
+    h->entrycount   = 0;
+    h->hashfn       = hashf;
+    h->eqfn         = eqf;
+    h->loadlimit    = (unsigned int) ceil(size * max_load_factor);
+
+	*hp = h;
+	return SWITCH_STATUS_SUCCESS;
+}
+
+/*****************************************************************************/
+static int
+hashtable_expand(switch_hashtable_t *h)
+{
+    /* Double the size of the table to accomodate more entries */
+    struct entry **newtable;
+    struct entry *e;
+    struct entry **pE;
+    unsigned int newsize, i, index;
+    /* Check we're not hitting max capacity */
+    if (h->primeindex == (prime_table_length - 1)) return 0;
+    newsize = primes[++(h->primeindex)];
+
+    newtable = (struct entry **)malloc(sizeof(struct entry*) * newsize);
+    if (NULL != newtable)
+		{
+			memset(newtable, 0, newsize * sizeof(struct entry *));
+			/* This algorithm is not 'stable'. ie. it reverses the list
+			 * when it transfers entries between the tables */
+			for (i = 0; i < h->tablelength; i++) {
+				while (NULL != (e = h->table[i])) {
+					h->table[i] = e->next;
+					index = indexFor(newsize,e->h);
+					e->next = newtable[index];
+					newtable[index] = e;
+				}
+			}
+			switch_safe_free(h->table);
+			h->table = newtable;
+		}
+    /* Plan B: realloc instead */
+    else 
+		{
+			newtable = (struct entry **)
+				realloc(h->table, newsize * sizeof(struct entry *));
+			if (NULL == newtable) { (h->primeindex)--; return 0; }
+			h->table = newtable;
+			memset(newtable[h->tablelength], 0, newsize - h->tablelength);
+			for (i = 0; i < h->tablelength; i++) {
+				for (pE = &(newtable[i]), e = *pE; e != NULL; e = *pE) {
+					index = indexFor(newsize,e->h);
+
+					if (index == i) {
+						pE = &(e->next);
+					} else {
+						*pE = e->next;
+						e->next = newtable[index];
+						newtable[index] = e;
+					}
+				}
+			}
+		}
+    h->tablelength = newsize;
+    h->loadlimit   = (unsigned int) ceil(newsize * max_load_factor);
+    return -1;
+}
+
+/*****************************************************************************/
+SWITCH_DECLARE(unsigned int)
+switch_hashtable_count(switch_hashtable_t *h)
+{
+    return h->entrycount;
+}
+
+/*****************************************************************************/
+SWITCH_DECLARE(int)
+switch_hashtable_insert(switch_hashtable_t *h, void *k, void *v, hashtable_flag_t flags)
+{
+    /* This method allows duplicate keys - but they shouldn't be used */
+    unsigned int index;
+    struct entry *e;
+    if (++(h->entrycount) > h->loadlimit)
+		{
+			/* Ignore the return value. If expand fails, we should
+			 * still try cramming just this value into the existing table
+			 * -- we may not have memory for a larger table, but one more
+			 * element may be ok. Next time we insert, we'll try expanding again.*/
+			hashtable_expand(h);
+		}
+    e = (struct entry *)malloc(sizeof(struct entry));
+    if (NULL == e) { --(h->entrycount); return 0; } /*oom*/
+    e->h = hash(h,k);
+    index = indexFor(h->tablelength,e->h);
+    e->k = k;
+    e->v = v;
+	e->flags = flags;
+    e->next = h->table[index];
+    h->table[index] = e;
+    return -1;
+}
+
+/*****************************************************************************/
+SWITCH_DECLARE(void *) /* returns value associated with key */
+switch_hashtable_search(switch_hashtable_t *h, void *k)
+{
+    struct entry *e;
+    unsigned int hashvalue, index;
+    hashvalue = hash(h,k);
+    index = indexFor(h->tablelength,hashvalue);
+    e = h->table[index];
+    while (NULL != e) {
+		/* Check hash value to short circuit heavier comparison */
+		if ((hashvalue == e->h) && (h->eqfn(k, e->k))) return e->v;
+		e = e->next;
+	}
+    return NULL;
+}
+
+/*****************************************************************************/
+SWITCH_DECLARE(void *) /* returns value associated with key */
+switch_hashtable_remove(switch_hashtable_t *h, void *k)
+{
+    /* TODO: consider compacting the table when the load factor drops enough,
+     *       or provide a 'compact' method. */
+
+    struct entry *e;
+    struct entry **pE;
+    void *v;
+    unsigned int hashvalue, index;
+
+    hashvalue = hash(h,k);
+    index = indexFor(h->tablelength,hash(h,k));
+    pE = &(h->table[index]);
+    e = *pE;
+    while (NULL != e) {
+		/* Check hash value to short circuit heavier comparison */
+		if ((hashvalue == e->h) && (h->eqfn(k, e->k))) {
+			*pE = e->next;
+			h->entrycount--;
+			v = e->v;
+			if (e->flags & HASHTABLE_FLAG_FREE_KEY) {
+				freekey(e->k);
+			}
+			switch_safe_free(e);
+			return v;
+		}
+		pE = &(e->next);
+		e = e->next;
+	}
+    return NULL;
+}
+
+/*****************************************************************************/
+/* destroy */
+SWITCH_DECLARE(void)
+switch_hashtable_destroy(switch_hashtable_t **h)
+{
+    unsigned int i;
+    struct entry *e, *f;
+    struct entry **table = (*h)->table;
+
+	for (i = 0; i < (*h)->tablelength; i++) {
+		e = table[i];
+		while (NULL != e) {
+			f = e; e = e->next; 
+
+			if (f->flags & HASHTABLE_FLAG_FREE_KEY) {
+				freekey(f->k); 
+			}
+			
+			if (f->flags & HASHTABLE_FLAG_FREE_VALUE) {
+				switch_safe_free(f->v); 
+			}
+			switch_safe_free(f); 
+		}
+	}
+    
+    switch_safe_free((*h)->table);
+	free(*h);
+	*h = NULL;
+}
+
+SWITCH_DECLARE(switch_hashtable_iterator_t *) switch_hashtable_next(switch_hashtable_iterator_t *i)
+{
+
+	if (i->e) {
+		if ((i->e = i->e->next) != 0) { 
+			return i;
+		} else {
+			i->pos++;
+		}
+	}
+
+	while(i->pos < i->h->tablelength && !i->h->table[i->pos]) {
+		i->pos++;
+	}
+	
+	if (i->pos >= i->h->tablelength) {
+		return NULL;
+	}
+	
+	if ((i->e = i->h->table[i->pos]) != 0) { 
+		return i;
+	}
+
+	return NULL;
+}
+
+SWITCH_DECLARE(switch_hashtable_iterator_t *) switch_hashtable_first(switch_hashtable_t *h)
+{
+	h->iterator.pos = 0;
+	h->iterator.e = NULL;
+	h->iterator.h = h;
+	return switch_hashtable_next(&h->iterator);
+}
+
+
+
+SWITCH_DECLARE(void) switch_hashtable_this(switch_hashtable_iterator_t *i, const void **key, switch_ssize_t *klen, void **val)
+{
+	if (i->e) {
+		if (key) {
+			*key = i->e->k;
+		}
+		if (klen) {
+			*klen = (int)strlen(i->e->k);
+		}
+		if (val) {
+			*val = i->e->v;
+		}
+	} else {
+		if (key) {
+			*key = NULL;
+		}
+		if (klen) {
+			*klen = 0;
+		}
+		if (val) {
+			*val = NULL;
+		}
+	}
+}
+
+
+/* For Emacs:
+ * Local Variables:
+ * mode:c
+ * indent-tabs-mode:t
+ * tab-width:4
+ * c-basic-offset:4
+ * End:
+ * For VIM:
+ * vim:set softtabstop=4 shiftwidth=4 tabstop=4 noet:
+ */
+