diff --git a/model/ndn_contentstore.cc b/model/ndn_contentstore.cc
new file mode 100644
index 0000000..61d6452
--- /dev/null
+++ b/model/ndn_contentstore.cc
@@ -0,0 +1,123 @@
+/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2011 University of California, Los Angeles
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author: Ilya Moiseenko <iliamo@cs.ucla.edu>
+ */
+
+#include "ndn_contentstore.h"
+
+namespace ns3
+{
+namespace NDNabstraction
+{
+    
+ContentStore::ContentStore( int maxSize )
+: m_maxSize(maxSize) { }
+
+
+ContentStore::~ContentStore( ) 
+{ }
+
+//Find corresponding CS entry for the given content name
+CsEntry* 
+ContentStore::Lookup(const char *prefix )
+{
+	CriticalSection section(m_csMutex);
+    
+    struct CsEntry *result = NULL;
+    
+    HASH_FIND_STR (m_contentStore, prefix, result);
+    
+    if(result != NULL)
+        Promote (*result);
+    
+	return result;
+}
+
+
+
+//Add entry to content store, if content store is full, use LRU replacement
+void 
+ContentStore::Add( const char *contentName, int contentSize )
+{
+    CriticalSection section(m_csMutex);
+    
+    // removing the old record
+    struct CsEntry *tmp = NULL;
+    HASH_FIND_STR (m_contentStore, contentName, tmp);
+    HASH_DELETE (hh, m_contentStore,tmp);
+    //free(tmp);
+    
+    int size = (int)HASH_COUNT(m_contentStore);
+    
+	if(size == m_maxSize )
+	{
+		CsEntry *entry = m_LRU.back();
+        HASH_DELETE (hh, m_contentStore,entry);//_cs.erase( entry->contentName );
+		m_LRU.pop_back( );
+	}
+    
+	struct CsEntry *ce = (struct CsEntry*)malloc(sizeof(struct CsEntry));
+	ce->contentName = (char*)contentName;
+	ce->contentSize = contentSize;
+    
+	//_cs[ contentName ] = ce;
+    HASH_ADD_KEYPTR (hh, m_contentStore, ce->contentName, strlen(ce->contentName), ce);
+    
+	//CsEntry *ce_in_hash = &(_cs[ contentName ]);
+    struct CsEntry *ce_in_hash = NULL;
+    HASH_FIND_STR (m_contentStore, contentName, ce_in_hash);
+	m_LRU.push_front( ce_in_hash );
+	ce_in_hash->lruPosition = m_LRU.begin( );
+}
+
+
+//move the given CS entry to the head of the list
+void 
+ContentStore::Promote(CsEntry &ce )
+{
+	// should not lock mutex. Otherwise deadlocks will be welcome
+	if( m_LRU.front() == &ce ) return;
+    
+	//assert( *(ce.lruPosition)==&ce ); // should point to the same object
+    
+	// swaping positions in _lru
+	m_LRU.erase( ce.lruPosition );
+	m_LRU.push_front( &ce );
+	ce.lruPosition = m_LRU.begin( );
+    
+	//assert( *(ce.lruPosition)==&ce ); // should point to the same object
+}
+
+void 
+ContentStore::Dump()
+{
+	CriticalSection section(m_csMutex);
+    
+    struct CsEntry *s, *tmp;
+    
+    HASH_ITER(hh, m_contentStore, s, tmp) 
+    {
+        printf("-%s-", s->contentName);
+        /* ... it is safe to delete and free s here */
+    }
+    
+    printf("\n");
+    
+}
+}
+}
diff --git a/model/ndn_contentstore.h b/model/ndn_contentstore.h
new file mode 100644
index 0000000..7e49fb6
--- /dev/null
+++ b/model/ndn_contentstore.h
@@ -0,0 +1,83 @@
+/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2011 University of California, Los Angeles
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author: Ilya Moiseenko <iliamo@cs.ucla.edu>
+ */
+
+#ifndef ndn_contentstore_h
+#define	ndn_contentstore_h
+
+#include <ns3/system-mutex.h>
+#include <list>
+#include <string>
+#include "uthash.h"
+
+using namespace std;
+
+//size of content store
+#define NDN_CONTENT_STORE_SIZE 100
+
+namespace  ns3
+{
+namespace NDNabstraction
+{
+    
+class CsEntry;
+typedef list<CsEntry*>::iterator CsLruIterator;
+    
+//structure for CS entry
+struct CsEntry
+{
+    char *contentName;
+    int contentSize;
+    
+	CsLruIterator lruPosition;
+    UT_hash_handle hh;         /* makes this structure hashable */
+};
+
+
+class ContentStore
+{
+public:
+	ContentStore( int max_size=NDN_CONTENT_STORE_SIZE );
+	virtual ~ContentStore( );
+    
+	// Find corresponding CS entry for the given content name
+	CsEntry* Lookup( const char *prefix );
+	//bool isValid( const CsIterator &it ) { return it!=_cs.end(); }
+	
+	// Add new content to the content store. Old content will be replaced
+	void Add( const char *contentName, int contentSize );
+    
+	// Dump content store entries
+	void Dump( );
+    
+protected:
+	//move the given CS entry to the head of the list
+	void Promote( CsEntry &entry );
+    
+private:
+	int                   m_maxSize; // maximum number of entries in cache
+    
+    struct CsEntry  *m_contentStore;     // actual content store
+	list<CsEntry*>			  m_LRU;	// LRU index of the content store
+	SystemMutex				m_csMutex;   // just to make sure we are not
+};
+    
+}
+}
+#endif
diff --git a/model/uthash.h b/model/uthash.h
new file mode 100644
index 0000000..b1e0d49
--- /dev/null
+++ b/model/uthash.h
@@ -0,0 +1,904 @@
+/*
+ Copyright (c) 2003-2011, Troy D. Hanson     http://uthash.sourceforge.net
+ 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.
+ 
+ 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.
+ */
+
+#ifndef UTHASH_H
+#define UTHASH_H 
+
+#include <string.h>   /* memcmp,strlen */
+#include <stddef.h>   /* ptrdiff_t */
+#include <stdlib.h>   /* exit() */
+
+/* These macros use decltype or the earlier __typeof GNU extension.
+ As decltype is only available in newer compilers (VS2010 or gcc 4.3+
+ when compiling c++ source) this code uses whatever method is needed
+ or, for VS2008 where neither is available, uses casting workarounds. */
+#ifdef _MSC_VER         /* MS compiler */
+#if _MSC_VER >= 1600 && defined(__cplusplus)  /* VS2010 or newer in C++ mode */
+#define DECLTYPE(x) (decltype(x))
+#else                   /* VS2008 or older (or VS2010 in C mode) */
+#define NO_DECLTYPE
+#define DECLTYPE(x)
+#endif
+#else                   /* GNU, Sun and other compilers */
+#define DECLTYPE(x) (__typeof(x))
+#endif
+
+#ifdef NO_DECLTYPE
+#define DECLTYPE_ASSIGN(dst,src)                                                 \
+do {                                                                             \
+char **_da_dst = (char**)(&(dst));                                             \
+*_da_dst = (char*)(src);                                                       \
+} while(0)
+#else 
+#define DECLTYPE_ASSIGN(dst,src)                                                 \
+do {                                                                             \
+(dst) = DECLTYPE(dst)(src);                                                    \
+} while(0)
+#endif
+
+/* a number of the hash function use uint32_t which isn't defined on win32 */
+#ifdef _MSC_VER
+typedef unsigned int uint32_t;
+typedef unsigned char uint8_t;
+#else
+#include <inttypes.h>   /* uint32_t */
+#endif
+
+#define UTHASH_VERSION 1.9.4
+
+#define uthash_fatal(msg) exit(-1)        /* fatal error (out of memory,etc) */
+#define uthash_malloc(sz) malloc(sz)      /* malloc fcn                      */
+#define uthash_free(ptr,sz) free(ptr)     /* free fcn                        */
+
+#define uthash_noexpand_fyi(tbl)          /* can be defined to log noexpand  */
+#define uthash_expand_fyi(tbl)            /* can be defined to log expands   */
+
+/* initial number of buckets */
+#define HASH_INITIAL_NUM_BUCKETS 32      /* initial number of buckets        */
+#define HASH_INITIAL_NUM_BUCKETS_LOG2 5  /* lg2 of initial number of buckets */
+#define HASH_BKT_CAPACITY_THRESH 10      /* expand when bucket count reaches */
+
+/* calculate the element whose hash handle address is hhe */
+#define ELMT_FROM_HH(tbl,hhp) ((void*)(((char*)(hhp)) - ((tbl)->hho)))
+
+#define HASH_FIND(hh,head,keyptr,keylen,out)                                     \
+do {                                                                             \
+unsigned _hf_bkt,_hf_hashv;                                                    \
+out=NULL;                                                                      \
+if (head) {                                                                    \
+HASH_FCN(keyptr,keylen, (head)->hh.tbl->num_buckets, _hf_hashv, _hf_bkt);   \
+if (HASH_BLOOM_TEST((head)->hh.tbl, _hf_hashv)) {                           \
+HASH_FIND_IN_BKT((head)->hh.tbl, hh, (head)->hh.tbl->buckets[ _hf_bkt ],  \
+keyptr,keylen,out);                                      \
+}                                                                           \
+}                                                                              \
+} while (0)
+
+#ifdef HASH_BLOOM
+#define HASH_BLOOM_BITLEN (1ULL << HASH_BLOOM)
+#define HASH_BLOOM_BYTELEN (HASH_BLOOM_BITLEN/8) + ((HASH_BLOOM_BITLEN%8) ? 1:0)
+#define HASH_BLOOM_MAKE(tbl)                                                     \
+do {                                                                             \
+(tbl)->bloom_nbits = HASH_BLOOM;                                               \
+(tbl)->bloom_bv = (uint8_t*)uthash_malloc(HASH_BLOOM_BYTELEN);                 \
+if (!((tbl)->bloom_bv))  { uthash_fatal( "out of memory"); }                   \
+memset((tbl)->bloom_bv, 0, HASH_BLOOM_BYTELEN);                                \
+(tbl)->bloom_sig = HASH_BLOOM_SIGNATURE;                                       \
+} while (0);
+
+#define HASH_BLOOM_FREE(tbl)                                                     \
+do {                                                                             \
+uthash_free((tbl)->bloom_bv, HASH_BLOOM_BYTELEN);                              \
+} while (0);
+
+#define HASH_BLOOM_BITSET(bv,idx) (bv[(idx)/8] |= (1U << ((idx)%8)))
+#define HASH_BLOOM_BITTEST(bv,idx) (bv[(idx)/8] & (1U << ((idx)%8)))
+
+#define HASH_BLOOM_ADD(tbl,hashv)                                                \
+HASH_BLOOM_BITSET((tbl)->bloom_bv, (hashv & (uint32_t)((1ULL << (tbl)->bloom_nbits) - 1)))
+
+#define HASH_BLOOM_TEST(tbl,hashv)                                               \
+HASH_BLOOM_BITTEST((tbl)->bloom_bv, (hashv & (uint32_t)((1ULL << (tbl)->bloom_nbits) - 1)))
+
+#else
+#define HASH_BLOOM_MAKE(tbl) 
+#define HASH_BLOOM_FREE(tbl) 
+#define HASH_BLOOM_ADD(tbl,hashv) 
+#define HASH_BLOOM_TEST(tbl,hashv) (1)
+#endif
+
+#define HASH_MAKE_TABLE(hh,head)                                                 \
+do {                                                                             \
+(head)->hh.tbl = (UT_hash_table*)uthash_malloc(                                \
+sizeof(UT_hash_table));                                        \
+if (!((head)->hh.tbl))  { uthash_fatal( "out of memory"); }                    \
+memset((head)->hh.tbl, 0, sizeof(UT_hash_table));                              \
+(head)->hh.tbl->tail = &((head)->hh);                                          \
+(head)->hh.tbl->num_buckets = HASH_INITIAL_NUM_BUCKETS;                        \
+(head)->hh.tbl->log2_num_buckets = HASH_INITIAL_NUM_BUCKETS_LOG2;              \
+(head)->hh.tbl->hho = (char*)(&(head)->hh) - (char*)(head);                    \
+(head)->hh.tbl->buckets = (UT_hash_bucket*)uthash_malloc(                      \
+HASH_INITIAL_NUM_BUCKETS*sizeof(struct UT_hash_bucket));               \
+if (! (head)->hh.tbl->buckets) { uthash_fatal( "out of memory"); }             \
+memset((head)->hh.tbl->buckets, 0,                                             \
+HASH_INITIAL_NUM_BUCKETS*sizeof(struct UT_hash_bucket));               \
+HASH_BLOOM_MAKE((head)->hh.tbl);                                               \
+(head)->hh.tbl->signature = HASH_SIGNATURE;                                    \
+} while(0)
+
+#define HASH_ADD(hh,head,fieldname,keylen_in,add)                                \
+HASH_ADD_KEYPTR(hh,head,&add->fieldname,keylen_in,add)
+
+#define HASH_ADD_KEYPTR(hh,head,keyptr,keylen_in,add)                            \
+do {                                                                             \
+unsigned _ha_bkt;                                                               \
+(add)->hh.next = NULL;                                                          \
+(add)->hh.key = (char*)keyptr;                                                  \
+(add)->hh.keylen = keylen_in;                                                   \
+if (!(head)) {                                                                  \
+head = (add);                                                                \
+(head)->hh.prev = NULL;                                                      \
+HASH_MAKE_TABLE(hh,head);                                                    \
+} else {                                                                        \
+(head)->hh.tbl->tail->next = (add);                                          \
+(add)->hh.prev = ELMT_FROM_HH((head)->hh.tbl, (head)->hh.tbl->tail);         \
+(head)->hh.tbl->tail = &((add)->hh);                                         \
+}                                                                               \
+(head)->hh.tbl->num_items++;                                                    \
+(add)->hh.tbl = (head)->hh.tbl;                                                 \
+HASH_FCN(keyptr,keylen_in, (head)->hh.tbl->num_buckets,                         \
+(add)->hh.hashv, _ha_bkt);                                              \
+HASH_ADD_TO_BKT((head)->hh.tbl->buckets[_ha_bkt],&(add)->hh);                   \
+HASH_BLOOM_ADD((head)->hh.tbl,(add)->hh.hashv);                                 \
+HASH_EMIT_KEY(hh,head,keyptr,keylen_in);                                        \
+HASH_FSCK(hh,head);                                                             \
+} while(0)
+
+#define HASH_TO_BKT( hashv, num_bkts, bkt )                                      \
+do {                                                                             \
+bkt = ((hashv) & ((num_bkts) - 1));                                            \
+} while(0)
+
+/* delete "delptr" from the hash table.
+ * "the usual" patch-up process for the app-order doubly-linked-list.
+ * The use of _hd_hh_del below deserves special explanation.
+ * These used to be expressed using (delptr) but that led to a bug
+ * if someone used the same symbol for the head and deletee, like
+ *  HASH_DELETE(hh,users,users);
+ * We want that to work, but by changing the head (users) below
+ * we were forfeiting our ability to further refer to the deletee (users)
+ * in the patch-up process. Solution: use scratch space to
+ * copy the deletee pointer, then the latter references are via that
+ * scratch pointer rather than through the repointed (users) symbol.
+ */
+#define HASH_DELETE(hh,head,delptr)                                              \
+do {                                                                             \
+unsigned _hd_bkt;                                                            \
+struct UT_hash_handle *_hd_hh_del;                                           \
+if ( ((delptr)->hh.prev == NULL) && ((delptr)->hh.next == NULL) )  {         \
+uthash_free((head)->hh.tbl->buckets,                                     \
+(head)->hh.tbl->num_buckets*sizeof(struct UT_hash_bucket) ); \
+HASH_BLOOM_FREE((head)->hh.tbl);                                         \
+uthash_free((head)->hh.tbl, sizeof(UT_hash_table));                      \
+head = NULL;                                                             \
+} else {                                                                     \
+_hd_hh_del = &((delptr)->hh);                                            \
+if ((delptr) == ELMT_FROM_HH((head)->hh.tbl,(head)->hh.tbl->tail)) {     \
+(head)->hh.tbl->tail =                                               \
+(UT_hash_handle*)((char*)((delptr)->hh.prev) +                   \
+(head)->hh.tbl->hho);                                            \
+}                                                                        \
+if ((delptr)->hh.prev) {                                                 \
+((UT_hash_handle*)((char*)((delptr)->hh.prev) +                      \
+(head)->hh.tbl->hho))->next = (delptr)->hh.next;             \
+} else {                                                                 \
+DECLTYPE_ASSIGN(head,(delptr)->hh.next);                             \
+}                                                                        \
+if (_hd_hh_del->next) {                                                  \
+((UT_hash_handle*)((char*)_hd_hh_del->next +                         \
+(head)->hh.tbl->hho))->prev =                                \
+_hd_hh_del->prev;                                            \
+}                                                                        \
+HASH_TO_BKT( _hd_hh_del->hashv, (head)->hh.tbl->num_buckets, _hd_bkt);   \
+HASH_DEL_IN_BKT(hh,(head)->hh.tbl->buckets[_hd_bkt], _hd_hh_del);        \
+(head)->hh.tbl->num_items--;                                             \
+}                                                                            \
+HASH_FSCK(hh,head);                                                          \
+} while (0)
+
+
+/* convenience forms of HASH_FIND/HASH_ADD/HASH_DEL */
+#define HASH_FIND_STR(head,findstr,out)                                          \
+HASH_FIND(hh,head,findstr,strlen(findstr),out)
+#define HASH_ADD_STR(head,strfield,add)                                          \
+HASH_ADD(hh,head,strfield,strlen(add->strfield),add)
+#define HASH_FIND_INT(head,findint,out)                                          \
+HASH_FIND(hh,head,findint,sizeof(int),out)
+#define HASH_ADD_INT(head,intfield,add)                                          \
+HASH_ADD(hh,head,intfield,sizeof(int),add)
+#define HASH_FIND_PTR(head,findptr,out)                                          \
+HASH_FIND(hh,head,findptr,sizeof(void *),out)
+#define HASH_ADD_PTR(head,ptrfield,add)                                          \
+HASH_ADD(hh,head,ptrfield,sizeof(void *),add)
+#define HASH_DEL(head,delptr)                                                    \
+HASH_DELETE(hh,head,delptr)
+
+/* HASH_FSCK checks hash integrity on every add/delete when HASH_DEBUG is defined.
+ * This is for uthash developer only; it compiles away if HASH_DEBUG isn't defined.
+ */
+#ifdef HASH_DEBUG
+#define HASH_OOPS(...) do { fprintf(stderr,__VA_ARGS__); exit(-1); } while (0)
+#define HASH_FSCK(hh,head)                                                       \
+do {                                                                             \
+unsigned _bkt_i;                                                             \
+unsigned _count, _bkt_count;                                                 \
+char *_prev;                                                                 \
+struct UT_hash_handle *_thh;                                                 \
+if (head) {                                                                  \
+_count = 0;                                                              \
+for( _bkt_i = 0; _bkt_i < (head)->hh.tbl->num_buckets; _bkt_i++) {       \
+_bkt_count = 0;                                                      \
+_thh = (head)->hh.tbl->buckets[_bkt_i].hh_head;                      \
+_prev = NULL;                                                        \
+while (_thh) {                                                       \
+if (_prev != (char*)(_thh->hh_prev)) {                            \
+HASH_OOPS("invalid hh_prev %p, actual %p\n",                  \
+_thh->hh_prev, _prev );                                      \
+}                                                                 \
+_bkt_count++;                                                     \
+_prev = (char*)(_thh);                                            \
+_thh = _thh->hh_next;                                             \
+}                                                                    \
+_count += _bkt_count;                                                \
+if ((head)->hh.tbl->buckets[_bkt_i].count !=  _bkt_count) {          \
+HASH_OOPS("invalid bucket count %d, actual %d\n",                 \
+(head)->hh.tbl->buckets[_bkt_i].count, _bkt_count);              \
+}                                                                    \
+}                                                                        \
+if (_count != (head)->hh.tbl->num_items) {                               \
+HASH_OOPS("invalid hh item count %d, actual %d\n",                   \
+(head)->hh.tbl->num_items, _count );                             \
+}                                                                        \
+/* traverse hh in app order; check next/prev integrity, count */         \
+_count = 0;                                                              \
+_prev = NULL;                                                            \
+_thh =  &(head)->hh;                                                     \
+while (_thh) {                                                           \
+_count++;                                                             \
+if (_prev !=(char*)(_thh->prev)) {                                    \
+HASH_OOPS("invalid prev %p, actual %p\n",                          \
+_thh->prev, _prev );                                         \
+}                                                                     \
+_prev = (char*)ELMT_FROM_HH((head)->hh.tbl, _thh);                    \
+_thh = ( _thh->next ?  (UT_hash_handle*)((char*)(_thh->next) +        \
+(head)->hh.tbl->hho) : NULL );                 \
+}                                                                        \
+if (_count != (head)->hh.tbl->num_items) {                               \
+HASH_OOPS("invalid app item count %d, actual %d\n",                  \
+(head)->hh.tbl->num_items, _count );                             \
+}                                                                        \
+}                                                                            \
+} while (0)
+#else
+#define HASH_FSCK(hh,head) 
+#endif
+
+/* When compiled with -DHASH_EMIT_KEYS, length-prefixed keys are emitted to 
+ * the descriptor to which this macro is defined for tuning the hash function.
+ * The app can #include <unistd.h> to get the prototype for write(2). */
+#ifdef HASH_EMIT_KEYS
+#define HASH_EMIT_KEY(hh,head,keyptr,fieldlen)                                   \
+do {                                                                             \
+unsigned _klen = fieldlen;                                                   \
+write(HASH_EMIT_KEYS, &_klen, sizeof(_klen));                                \
+write(HASH_EMIT_KEYS, keyptr, fieldlen);                                     \
+} while (0)
+#else 
+#define HASH_EMIT_KEY(hh,head,keyptr,fieldlen)                    
+#endif
+
+/* default to Jenkin's hash unless overridden e.g. DHASH_FUNCTION=HASH_SAX */
+#ifdef HASH_FUNCTION 
+#define HASH_FCN HASH_FUNCTION
+#else
+#define HASH_FCN HASH_JEN
+#endif
+
+/* The Bernstein hash function, used in Perl prior to v5.6 */
+#define HASH_BER(key,keylen,num_bkts,hashv,bkt)                                  \
+do {                                                                             \
+unsigned _hb_keylen=keylen;                                                    \
+char *_hb_key=(char*)(key);                                                    \
+(hashv) = 0;                                                                   \
+while (_hb_keylen--)  { (hashv) = ((hashv) * 33) + *_hb_key++; }               \
+bkt = (hashv) & (num_bkts-1);                                                  \
+} while (0)
+
+
+/* SAX/FNV/OAT/JEN hash functions are macro variants of those listed at 
+ * http://eternallyconfuzzled.com/tuts/algorithms/jsw_tut_hashing.aspx */
+#define HASH_SAX(key,keylen,num_bkts,hashv,bkt)                                  \
+do {                                                                             \
+unsigned _sx_i;                                                                \
+char *_hs_key=(char*)(key);                                                    \
+hashv = 0;                                                                     \
+for(_sx_i=0; _sx_i < keylen; _sx_i++)                                          \
+hashv ^= (hashv << 5) + (hashv >> 2) + _hs_key[_sx_i];                     \
+bkt = hashv & (num_bkts-1);                                                    \
+} while (0)
+
+#define HASH_FNV(key,keylen,num_bkts,hashv,bkt)                                  \
+do {                                                                             \
+unsigned _fn_i;                                                                \
+char *_hf_key=(char*)(key);                                                    \
+hashv = 2166136261UL;                                                          \
+for(_fn_i=0; _fn_i < keylen; _fn_i++)                                          \
+hashv = (hashv * 16777619) ^ _hf_key[_fn_i];                               \
+bkt = hashv & (num_bkts-1);                                                    \
+} while(0);
+
+#define HASH_OAT(key,keylen,num_bkts,hashv,bkt)                                  \
+do {                                                                             \
+unsigned _ho_i;                                                                \
+char *_ho_key=(char*)(key);                                                    \
+hashv = 0;                                                                     \
+for(_ho_i=0; _ho_i < keylen; _ho_i++) {                                        \
+hashv += _ho_key[_ho_i];                                                   \
+hashv += (hashv << 10);                                                    \
+hashv ^= (hashv >> 6);                                                     \
+}                                                                              \
+hashv += (hashv << 3);                                                         \
+hashv ^= (hashv >> 11);                                                        \
+hashv += (hashv << 15);                                                        \
+bkt = hashv & (num_bkts-1);                                                    \
+} while(0)
+
+#define HASH_JEN_MIX(a,b,c)                                                      \
+do {                                                                             \
+a -= b; a -= c; a ^= ( c >> 13 );                                              \
+b -= c; b -= a; b ^= ( a << 8 );                                               \
+c -= a; c -= b; c ^= ( b >> 13 );                                              \
+a -= b; a -= c; a ^= ( c >> 12 );                                              \
+b -= c; b -= a; b ^= ( a << 16 );                                              \
+c -= a; c -= b; c ^= ( b >> 5 );                                               \
+a -= b; a -= c; a ^= ( c >> 3 );                                               \
+b -= c; b -= a; b ^= ( a << 10 );                                              \
+c -= a; c -= b; c ^= ( b >> 15 );                                              \
+} while (0)
+
+#define HASH_JEN(key,keylen,num_bkts,hashv,bkt)                                  \
+do {                                                                             \
+unsigned _hj_i,_hj_j,_hj_k;                                                    \
+char *_hj_key=(char*)(key);                                                    \
+hashv = 0xfeedbeef;                                                            \
+_hj_i = _hj_j = 0x9e3779b9;                                                    \
+_hj_k = keylen;                                                                \
+while (_hj_k >= 12) {                                                          \
+_hj_i +=    (_hj_key[0] + ( (unsigned)_hj_key[1] << 8 )                      \
++ ( (unsigned)_hj_key[2] << 16 )                                         \
++ ( (unsigned)_hj_key[3] << 24 ) );                                      \
+_hj_j +=    (_hj_key[4] + ( (unsigned)_hj_key[5] << 8 )                      \
++ ( (unsigned)_hj_key[6] << 16 )                                         \
++ ( (unsigned)_hj_key[7] << 24 ) );                                      \
+hashv += (_hj_key[8] + ( (unsigned)_hj_key[9] << 8 )                         \
++ ( (unsigned)_hj_key[10] << 16 )                                        \
++ ( (unsigned)_hj_key[11] << 24 ) );                                     \
+\
+HASH_JEN_MIX(_hj_i, _hj_j, hashv);                                          \
+\
+_hj_key += 12;                                                              \
+_hj_k -= 12;                                                                \
+}                                                                              \
+hashv += keylen;                                                               \
+switch ( _hj_k ) {                                                             \
+case 11: hashv += ( (unsigned)_hj_key[10] << 24 );                          \
+case 10: hashv += ( (unsigned)_hj_key[9] << 16 );                           \
+case 9:  hashv += ( (unsigned)_hj_key[8] << 8 );                            \
+case 8:  _hj_j += ( (unsigned)_hj_key[7] << 24 );                           \
+case 7:  _hj_j += ( (unsigned)_hj_key[6] << 16 );                           \
+case 6:  _hj_j += ( (unsigned)_hj_key[5] << 8 );                            \
+case 5:  _hj_j += _hj_key[4];                                               \
+case 4:  _hj_i += ( (unsigned)_hj_key[3] << 24 );                           \
+case 3:  _hj_i += ( (unsigned)_hj_key[2] << 16 );                           \
+case 2:  _hj_i += ( (unsigned)_hj_key[1] << 8 );                            \
+case 1:  _hj_i += _hj_key[0];                                               \
+}                                                                              \
+HASH_JEN_MIX(_hj_i, _hj_j, hashv);                                             \
+bkt = hashv & (num_bkts-1);                                                    \
+} while(0)
+
+/* The Paul Hsieh hash function */
+#undef get16bits
+#if (defined(__GNUC__) && defined(__i386__)) || defined(__WATCOMC__)             \
+|| defined(_MSC_VER) || defined (__BORLANDC__) || defined (__TURBOC__)
+#define get16bits(d) (*((const uint16_t *) (d)))
+#endif
+
+#if !defined (get16bits)
+#define get16bits(d) ((((uint32_t)(((const uint8_t *)(d))[1])) << 8)             \
++(uint32_t)(((const uint8_t *)(d))[0]) )
+#endif
+#define HASH_SFH(key,keylen,num_bkts,hashv,bkt)                                  \
+do {                                                                             \
+char *_sfh_key=(char*)(key);                                                   \
+uint32_t _sfh_tmp, _sfh_len = keylen;                                          \
+\
+int _sfh_rem = _sfh_len & 3;                                                   \
+_sfh_len >>= 2;                                                                \
+hashv = 0xcafebabe;                                                            \
+\
+/* Main loop */                                                                \
+for (;_sfh_len > 0; _sfh_len--) {                                              \
+hashv    += get16bits (_sfh_key);                                            \
+_sfh_tmp       = (get16bits (_sfh_key+2) << 11) ^ hashv;                     \
+hashv     = (hashv << 16) ^ _sfh_tmp;                                        \
+_sfh_key += 2*sizeof (uint16_t);                                             \
+hashv    += hashv >> 11;                                                     \
+}                                                                              \
+\
+/* Handle end cases */                                                         \
+switch (_sfh_rem) {                                                            \
+case 3: hashv += get16bits (_sfh_key);                                       \
+hashv ^= hashv << 16;                                                \
+hashv ^= _sfh_key[sizeof (uint16_t)] << 18;                          \
+hashv += hashv >> 11;                                                \
+break;                                                               \
+case 2: hashv += get16bits (_sfh_key);                                       \
+hashv ^= hashv << 11;                                                \
+hashv += hashv >> 17;                                                \
+break;                                                               \
+case 1: hashv += *_sfh_key;                                                  \
+hashv ^= hashv << 10;                                                \
+hashv += hashv >> 1;                                                 \
+}                                                                              \
+\
+/* Force "avalanching" of final 127 bits */                                  \
+hashv ^= hashv << 3;                                                         \
+hashv += hashv >> 5;                                                         \
+hashv ^= hashv << 4;                                                         \
+hashv += hashv >> 17;                                                        \
+hashv ^= hashv << 25;                                                        \
+hashv += hashv >> 6;                                                         \
+bkt = hashv & (num_bkts-1);                                                  \
+} while(0);
+
+#ifdef HASH_USING_NO_STRICT_ALIASING
+/* The MurmurHash exploits some CPU's (x86,x86_64) tolerance for unaligned reads.
+ * For other types of CPU's (e.g. Sparc) an unaligned read causes a bus error.
+ * MurmurHash uses the faster approach only on CPU's where we know it's safe. 
+ *
+ * Note the preprocessor built-in defines can be emitted using:
+ *
+ *   gcc -m64 -dM -E - < /dev/null                  (on gcc)
+ *   cc -## a.c (where a.c is a simple test file)   (Sun Studio)
+ */
+#if (defined(__i386__) || defined(__x86_64__)) 
+#define MUR_GETBLOCK(p,i) p[i]
+#else /* non intel */
+#define MUR_PLUS0_ALIGNED(p) (((unsigned long)p & 0x3) == 0)
+#define MUR_PLUS1_ALIGNED(p) (((unsigned long)p & 0x3) == 1)
+#define MUR_PLUS2_ALIGNED(p) (((unsigned long)p & 0x3) == 2)
+#define MUR_PLUS3_ALIGNED(p) (((unsigned long)p & 0x3) == 3)
+#define WP(p) ((uint32_t*)((unsigned long)(p) & ~3UL))
+#if (defined(__BIG_ENDIAN__) || defined(SPARC) || defined(__ppc__) || defined(__ppc64__))
+#define MUR_THREE_ONE(p) ((((*WP(p))&0x00ffffff) << 8) | (((*(WP(p)+1))&0xff000000) >> 24))
+#define MUR_TWO_TWO(p)   ((((*WP(p))&0x0000ffff) <<16) | (((*(WP(p)+1))&0xffff0000) >> 16))
+#define MUR_ONE_THREE(p) ((((*WP(p))&0x000000ff) <<24) | (((*(WP(p)+1))&0xffffff00) >>  8))
+#else /* assume little endian non-intel */
+#define MUR_THREE_ONE(p) ((((*WP(p))&0xffffff00) >> 8) | (((*(WP(p)+1))&0x000000ff) << 24))
+#define MUR_TWO_TWO(p)   ((((*WP(p))&0xffff0000) >>16) | (((*(WP(p)+1))&0x0000ffff) << 16))
+#define MUR_ONE_THREE(p) ((((*WP(p))&0xff000000) >>24) | (((*(WP(p)+1))&0x00ffffff) <<  8))
+#endif
+#define MUR_GETBLOCK(p,i) (MUR_PLUS0_ALIGNED(p) ? ((p)[i]) :           \
+(MUR_PLUS1_ALIGNED(p) ? MUR_THREE_ONE(p) : \
+(MUR_PLUS2_ALIGNED(p) ? MUR_TWO_TWO(p) :  \
+MUR_ONE_THREE(p))))
+#endif
+#define MUR_ROTL32(x,r) (((x) << (r)) | ((x) >> (32 - (r))))
+#define MUR_FMIX(_h) \
+do {                 \
+_h ^= _h >> 16;    \
+_h *= 0x85ebca6b;  \
+_h ^= _h >> 13;    \
+_h *= 0xc2b2ae35l; \
+_h ^= _h >> 16;    \
+} while(0)
+
+#define HASH_MUR(key,keylen,num_bkts,hashv,bkt)                        \
+do {                                                                   \
+const uint8_t *_mur_data = (const uint8_t*)(key);                    \
+const int _mur_nblocks = (keylen) / 4;                               \
+uint32_t _mur_h1 = 0xf88D5353;                                       \
+uint32_t _mur_c1 = 0xcc9e2d51;                                       \
+uint32_t _mur_c2 = 0x1b873593;                                       \
+const uint32_t *_mur_blocks = (const uint32_t*)(_mur_data+_mur_nblocks*4); \
+int _mur_i;                                                          \
+for(_mur_i = -_mur_nblocks; _mur_i; _mur_i++) {                      \
+uint32_t _mur_k1 = MUR_GETBLOCK(_mur_blocks,_mur_i);               \
+_mur_k1 *= _mur_c1;                                                \
+_mur_k1 = MUR_ROTL32(_mur_k1,15);                                  \
+_mur_k1 *= _mur_c2;                                                \
+\
+_mur_h1 ^= _mur_k1;                                                \
+_mur_h1 = MUR_ROTL32(_mur_h1,13);                                  \
+_mur_h1 = _mur_h1*5+0xe6546b64;                                    \
+}                                                                    \
+const uint8_t *_mur_tail = (const uint8_t*)(_mur_data + _mur_nblocks*4); \
+uint32_t _mur_k1=0;                                                  \
+switch((keylen) & 3) {                                               \
+case 3: _mur_k1 ^= _mur_tail[2] << 16;                             \
+case 2: _mur_k1 ^= _mur_tail[1] << 8;                              \
+case 1: _mur_k1 ^= _mur_tail[0];                                   \
+_mur_k1 *= _mur_c1;                                                \
+_mur_k1 = MUR_ROTL32(_mur_k1,15);                                  \
+_mur_k1 *= _mur_c2;                                                \
+_mur_h1 ^= _mur_k1;                                                \
+}                                                                    \
+_mur_h1 ^= (keylen);                                                 \
+MUR_FMIX(_mur_h1);                                                   \
+hashv = _mur_h1;                                                     \
+bkt = hashv & (num_bkts-1);                                          \
+} while(0)
+#endif  /* HASH_USING_NO_STRICT_ALIASING */
+
+/* key comparison function; return 0 if keys equal */
+#define HASH_KEYCMP(a,b,len) memcmp(a,b,len) 
+
+/* iterate over items in a known bucket to find desired item */
+#define HASH_FIND_IN_BKT(tbl,hh,head,keyptr,keylen_in,out)                       \
+do {                                                                             \
+if (head.hh_head) DECLTYPE_ASSIGN(out,ELMT_FROM_HH(tbl,head.hh_head));          \
+else out=NULL;                                                                  \
+while (out) {                                                                   \
+if (out->hh.keylen == keylen_in) {                                           \
+if ((HASH_KEYCMP(out->hh.key,keyptr,keylen_in)) == 0) break;             \
+}                                                                            \
+if (out->hh.hh_next) DECLTYPE_ASSIGN(out,ELMT_FROM_HH(tbl,out->hh.hh_next)); \
+else out = NULL;                                                             \
+}                                                                               \
+} while(0)
+
+/* add an item to a bucket  */
+#define HASH_ADD_TO_BKT(head,addhh)                                              \
+do {                                                                             \
+head.count++;                                                                   \
+(addhh)->hh_next = head.hh_head;                                                \
+(addhh)->hh_prev = NULL;                                                        \
+if (head.hh_head) { (head).hh_head->hh_prev = (addhh); }                        \
+(head).hh_head=addhh;                                                           \
+if (head.count >= ((head.expand_mult+1) * HASH_BKT_CAPACITY_THRESH)             \
+&& (addhh)->tbl->noexpand != 1) {                                           \
+HASH_EXPAND_BUCKETS((addhh)->tbl);                                        \
+}                                                                               \
+} while(0)
+
+/* remove an item from a given bucket */
+#define HASH_DEL_IN_BKT(hh,head,hh_del)                                          \
+(head).count--;                                                              \
+if ((head).hh_head == hh_del) {                                              \
+(head).hh_head = hh_del->hh_next;                                          \
+}                                                                            \
+if (hh_del->hh_prev) {                                                       \
+hh_del->hh_prev->hh_next = hh_del->hh_next;                              \
+}                                                                            \
+if (hh_del->hh_next) {                                                       \
+hh_del->hh_next->hh_prev = hh_del->hh_prev;                              \
+}                                                                
+
+/* Bucket expansion has the effect of doubling the number of buckets
+ * and redistributing the items into the new buckets. Ideally the
+ * items will distribute more or less evenly into the new buckets
+ * (the extent to which this is true is a measure of the quality of
+ * the hash function as it applies to the key domain). 
+ * 
+ * With the items distributed into more buckets, the chain length
+ * (item count) in each bucket is reduced. Thus by expanding buckets
+ * the hash keeps a bound on the chain length. This bounded chain 
+ * length is the essence of how a hash provides constant time lookup.
+ * 
+ * The calculation of tbl->ideal_chain_maxlen below deserves some
+ * explanation. First, keep in mind that we're calculating the ideal
+ * maximum chain length based on the *new* (doubled) bucket count.
+ * In fractions this is just n/b (n=number of items,b=new num buckets).
+ * Since the ideal chain length is an integer, we want to calculate 
+ * ceil(n/b). We don't depend on floating point arithmetic in this
+ * hash, so to calculate ceil(n/b) with integers we could write
+ * 
+ *      ceil(n/b) = (n/b) + ((n%b)?1:0)
+ * 
+ * and in fact a previous version of this hash did just that.
+ * But now we have improved things a bit by recognizing that b is
+ * always a power of two. We keep its base 2 log handy (call it lb),
+ * so now we can write this with a bit shift and logical AND:
+ * 
+ *      ceil(n/b) = (n>>lb) + ( (n & (b-1)) ? 1:0)
+ * 
+ */
+#define HASH_EXPAND_BUCKETS(tbl)                                                 \
+do {                                                                             \
+unsigned _he_bkt;                                                            \
+unsigned _he_bkt_i;                                                          \
+struct UT_hash_handle *_he_thh, *_he_hh_nxt;                                 \
+UT_hash_bucket *_he_new_buckets, *_he_newbkt;                                \
+_he_new_buckets = (UT_hash_bucket*)uthash_malloc(                            \
+2 * tbl->num_buckets * sizeof(struct UT_hash_bucket));              \
+if (!_he_new_buckets) { uthash_fatal( "out of memory"); }                    \
+memset(_he_new_buckets, 0,                                                   \
+2 * tbl->num_buckets * sizeof(struct UT_hash_bucket));               \
+tbl->ideal_chain_maxlen =                                                    \
+(tbl->num_items >> (tbl->log2_num_buckets+1)) +                           \
+((tbl->num_items & ((tbl->num_buckets*2)-1)) ? 1 : 0);                    \
+tbl->nonideal_items = 0;                                                     \
+for(_he_bkt_i = 0; _he_bkt_i < tbl->num_buckets; _he_bkt_i++)                \
+{                                                                            \
+_he_thh = tbl->buckets[ _he_bkt_i ].hh_head;                             \
+while (_he_thh) {                                                        \
+_he_hh_nxt = _he_thh->hh_next;                                        \
+HASH_TO_BKT( _he_thh->hashv, tbl->num_buckets*2, _he_bkt);            \
+_he_newbkt = &(_he_new_buckets[ _he_bkt ]);                           \
+if (++(_he_newbkt->count) > tbl->ideal_chain_maxlen) {                \
+tbl->nonideal_items++;                                              \
+_he_newbkt->expand_mult = _he_newbkt->count /                       \
+tbl->ideal_chain_maxlen;                 \
+}                                                                     \
+_he_thh->hh_prev = NULL;                                              \
+_he_thh->hh_next = _he_newbkt->hh_head;                               \
+if (_he_newbkt->hh_head) _he_newbkt->hh_head->hh_prev =               \
+_he_thh;                                                         \
+_he_newbkt->hh_head = _he_thh;                                        \
+_he_thh = _he_hh_nxt;                                                 \
+}                                                                        \
+}                                                                            \
+uthash_free( tbl->buckets, tbl->num_buckets*sizeof(struct UT_hash_bucket) ); \
+tbl->num_buckets *= 2;                                                       \
+tbl->log2_num_buckets++;                                                     \
+tbl->buckets = _he_new_buckets;                                              \
+tbl->ineff_expands = (tbl->nonideal_items > (tbl->num_items >> 1)) ?         \
+(tbl->ineff_expands+1) : 0;                                              \
+if (tbl->ineff_expands > 1) {                                                \
+tbl->noexpand=1;                                                         \
+uthash_noexpand_fyi(tbl);                                                \
+}                                                                            \
+uthash_expand_fyi(tbl);                                                      \
+} while(0)
+
+
+/* This is an adaptation of Simon Tatham's O(n log(n)) mergesort */
+/* Note that HASH_SORT assumes the hash handle name to be hh. 
+ * HASH_SRT was added to allow the hash handle name to be passed in. */
+#define HASH_SORT(head,cmpfcn) HASH_SRT(hh,head,cmpfcn)
+#define HASH_SRT(hh,head,cmpfcn)                                                 \
+do {                                                                             \
+unsigned _hs_i;                                                                \
+unsigned _hs_looping,_hs_nmerges,_hs_insize,_hs_psize,_hs_qsize;               \
+struct UT_hash_handle *_hs_p, *_hs_q, *_hs_e, *_hs_list, *_hs_tail;            \
+if (head) {                                                                    \
+_hs_insize = 1;                                                            \
+_hs_looping = 1;                                                           \
+_hs_list = &((head)->hh);                                                  \
+while (_hs_looping) {                                                      \
+_hs_p = _hs_list;                                                      \
+_hs_list = NULL;                                                       \
+_hs_tail = NULL;                                                       \
+_hs_nmerges = 0;                                                       \
+while (_hs_p) {                                                        \
+_hs_nmerges++;                                                     \
+_hs_q = _hs_p;                                                     \
+_hs_psize = 0;                                                     \
+for ( _hs_i = 0; _hs_i  < _hs_insize; _hs_i++ ) {                  \
+_hs_psize++;                                                   \
+_hs_q = (UT_hash_handle*)((_hs_q->next) ?                      \
+((void*)((char*)(_hs_q->next) +                        \
+(head)->hh.tbl->hho)) : NULL);                         \
+if (! (_hs_q) ) break;                                         \
+}                                                                  \
+_hs_qsize = _hs_insize;                                            \
+while ((_hs_psize > 0) || ((_hs_qsize > 0) && _hs_q )) {           \
+if (_hs_psize == 0) {                                          \
+_hs_e = _hs_q;                                             \
+_hs_q = (UT_hash_handle*)((_hs_q->next) ?                  \
+((void*)((char*)(_hs_q->next) +                    \
+(head)->hh.tbl->hho)) : NULL);                     \
+_hs_qsize--;                                               \
+} else if ( (_hs_qsize == 0) || !(_hs_q) ) {                   \
+_hs_e = _hs_p;                                             \
+_hs_p = (UT_hash_handle*)((_hs_p->next) ?                  \
+((void*)((char*)(_hs_p->next) +                    \
+(head)->hh.tbl->hho)) : NULL);                     \
+_hs_psize--;                                               \
+} else if ((                                                   \
+cmpfcn(DECLTYPE(head)(ELMT_FROM_HH((head)->hh.tbl,_hs_p)), \
+DECLTYPE(head)(ELMT_FROM_HH((head)->hh.tbl,_hs_q))) \
+) <= 0) {                                           \
+_hs_e = _hs_p;                                             \
+_hs_p = (UT_hash_handle*)((_hs_p->next) ?                  \
+((void*)((char*)(_hs_p->next) +                    \
+(head)->hh.tbl->hho)) : NULL);                     \
+_hs_psize--;                                               \
+} else {                                                       \
+_hs_e = _hs_q;                                             \
+_hs_q = (UT_hash_handle*)((_hs_q->next) ?                  \
+((void*)((char*)(_hs_q->next) +                    \
+(head)->hh.tbl->hho)) : NULL);                     \
+_hs_qsize--;                                               \
+}                                                              \
+if ( _hs_tail ) {                                              \
+_hs_tail->next = ((_hs_e) ?                                \
+ELMT_FROM_HH((head)->hh.tbl,_hs_e) : NULL);          \
+} else {                                                       \
+_hs_list = _hs_e;                                          \
+}                                                              \
+_hs_e->prev = ((_hs_tail) ?                                    \
+ELMT_FROM_HH((head)->hh.tbl,_hs_tail) : NULL);              \
+_hs_tail = _hs_e;                                              \
+}                                                                  \
+_hs_p = _hs_q;                                                     \
+}                                                                      \
+_hs_tail->next = NULL;                                                 \
+if ( _hs_nmerges <= 1 ) {                                              \
+_hs_looping=0;                                                     \
+(head)->hh.tbl->tail = _hs_tail;                                   \
+DECLTYPE_ASSIGN(head,ELMT_FROM_HH((head)->hh.tbl, _hs_list));      \
+}                                                                      \
+_hs_insize *= 2;                                                       \
+}                                                                          \
+HASH_FSCK(hh,head);                                                        \
+}                                                                               \
+} while (0)
+
+/* This function selects items from one hash into another hash. 
+ * The end result is that the selected items have dual presence 
+ * in both hashes. There is no copy of the items made; rather 
+ * they are added into the new hash through a secondary hash 
+ * hash handle that must be present in the structure. */
+#define HASH_SELECT(hh_dst, dst, hh_src, src, cond)                              \
+do {                                                                             \
+unsigned _src_bkt, _dst_bkt;                                                   \
+void *_last_elt=NULL, *_elt;                                                   \
+UT_hash_handle *_src_hh, *_dst_hh, *_last_elt_hh=NULL;                         \
+ptrdiff_t _dst_hho = ((char*)(&(dst)->hh_dst) - (char*)(dst));                 \
+if (src) {                                                                     \
+for(_src_bkt=0; _src_bkt < (src)->hh_src.tbl->num_buckets; _src_bkt++) {     \
+for(_src_hh = (src)->hh_src.tbl->buckets[_src_bkt].hh_head;                \
+_src_hh;                                                               \
+_src_hh = _src_hh->hh_next) {                                          \
+_elt = ELMT_FROM_HH((src)->hh_src.tbl, _src_hh);                       \
+if (cond(_elt)) {                                                      \
+_dst_hh = (UT_hash_handle*)(((char*)_elt) + _dst_hho);               \
+_dst_hh->key = _src_hh->key;                                         \
+_dst_hh->keylen = _src_hh->keylen;                                   \
+_dst_hh->hashv = _src_hh->hashv;                                     \
+_dst_hh->prev = _last_elt;                                           \
+_dst_hh->next = NULL;                                                \
+if (_last_elt_hh) { _last_elt_hh->next = _elt; }                     \
+if (!dst) {                                                          \
+DECLTYPE_ASSIGN(dst,_elt);                                         \
+HASH_MAKE_TABLE(hh_dst,dst);                                       \
+} else {                                                             \
+_dst_hh->tbl = (dst)->hh_dst.tbl;                                  \
+}                                                                    \
+HASH_TO_BKT(_dst_hh->hashv, _dst_hh->tbl->num_buckets, _dst_bkt);    \
+HASH_ADD_TO_BKT(_dst_hh->tbl->buckets[_dst_bkt],_dst_hh);            \
+(dst)->hh_dst.tbl->num_items++;                                      \
+_last_elt = _elt;                                                    \
+_last_elt_hh = _dst_hh;                                              \
+}                                                                      \
+}                                                                          \
+}                                                                            \
+}                                                                              \
+HASH_FSCK(hh_dst,dst);                                                         \
+} while (0)
+
+#define HASH_CLEAR(hh,head)                                                      \
+do {                                                                             \
+if (head) {                                                                    \
+uthash_free((head)->hh.tbl->buckets,                                         \
+(head)->hh.tbl->num_buckets*sizeof(struct UT_hash_bucket));      \
+uthash_free((head)->hh.tbl, sizeof(UT_hash_table));                          \
+(head)=NULL;                                                                 \
+}                                                                              \
+} while(0)
+
+#ifdef NO_DECLTYPE
+#define HASH_ITER(hh,head,el,tmp)                                                \
+for((el)=(head), (*(char**)(&(tmp)))=(char*)((head)?(head)->hh.next:NULL);       \
+el; (el)=(tmp),(*(char**)(&(tmp)))=(char*)((tmp)?(tmp)->hh.next:NULL)) 
+#else
+#define HASH_ITER(hh,head,el,tmp)                                                \
+for((el)=(head),(tmp)=DECLTYPE(el)((head)?(head)->hh.next:NULL);                 \
+el; (el)=(tmp),(tmp)=DECLTYPE(el)((tmp)?(tmp)->hh.next:NULL))
+#endif
+
+/* obtain a count of items in the hash */
+#define HASH_COUNT(head) HASH_CNT(hh,head) 
+#define HASH_CNT(hh,head) ((head)?((head)->hh.tbl->num_items):0)
+
+typedef struct UT_hash_bucket {
+    struct UT_hash_handle *hh_head;
+    unsigned count;
+    
+    /* expand_mult is normally set to 0. In this situation, the max chain length
+     * threshold is enforced at its default value, HASH_BKT_CAPACITY_THRESH. (If
+     * the bucket's chain exceeds this length, bucket expansion is triggered). 
+     * However, setting expand_mult to a non-zero value delays bucket expansion
+     * (that would be triggered by additions to this particular bucket)
+     * until its chain length reaches a *multiple* of HASH_BKT_CAPACITY_THRESH.
+     * (The multiplier is simply expand_mult+1). The whole idea of this
+     * multiplier is to reduce bucket expansions, since they are expensive, in
+     * situations where we know that a particular bucket tends to be overused.
+     * It is better to let its chain length grow to a longer yet-still-bounded
+     * value, than to do an O(n) bucket expansion too often. 
+     */
+    unsigned expand_mult;
+    
+} UT_hash_bucket;
+
+/* random signature used only to find hash tables in external analysis */
+#define HASH_SIGNATURE 0xa0111fe1
+#define HASH_BLOOM_SIGNATURE 0xb12220f2
+
+typedef struct UT_hash_table {
+    UT_hash_bucket *buckets;
+    unsigned num_buckets, log2_num_buckets;
+    unsigned num_items;
+    struct UT_hash_handle *tail; /* tail hh in app order, for fast append    */
+    ptrdiff_t hho; /* hash handle offset (byte pos of hash handle in element */
+    
+    /* in an ideal situation (all buckets used equally), no bucket would have
+     * more than ceil(#items/#buckets) items. that's the ideal chain length. */
+    unsigned ideal_chain_maxlen;
+    
+    /* nonideal_items is the number of items in the hash whose chain position
+     * exceeds the ideal chain maxlen. these items pay the penalty for an uneven
+     * hash distribution; reaching them in a chain traversal takes >ideal steps */
+    unsigned nonideal_items;
+    
+    /* ineffective expands occur when a bucket doubling was performed, but 
+     * afterward, more than half the items in the hash had nonideal chain
+     * positions. If this happens on two consecutive expansions we inhibit any
+     * further expansion, as it's not helping; this happens when the hash
+     * function isn't a good fit for the key domain. When expansion is inhibited
+     * the hash will still work, albeit no longer in constant time. */
+    unsigned ineff_expands, noexpand;
+    
+    uint32_t signature; /* used only to find hash tables in external analysis */
+#ifdef HASH_BLOOM
+    uint32_t bloom_sig; /* used only to test bloom exists in external analysis */
+    uint8_t *bloom_bv;
+    char bloom_nbits;
+#endif
+    
+} UT_hash_table;
+
+typedef struct UT_hash_handle {
+    struct UT_hash_table *tbl;
+    void *prev;                       /* prev element in app order      */
+    void *next;                       /* next element in app order      */
+    struct UT_hash_handle *hh_prev;   /* previous hh in bucket order    */
+    struct UT_hash_handle *hh_next;   /* next hh in bucket order        */
+    void *key;                        /* ptr to enclosing struct's key  */
+    unsigned keylen;                  /* enclosing struct's key len     */
+    unsigned hashv;                   /* result of hash-fcn(key)        */
+} UT_hash_handle;
+
+#endif /* UTHASH_H */
diff --git a/wscript b/wscript
index 42ca6d9..6b033ee 100644
--- a/wscript
+++ b/wscript
@@ -18,6 +18,7 @@
         'model/ndn_timeoutheader.cc',
         'model/ndn_nonceheader.cc',
         'model/name-components.cc',
+        'model/ndn_contentstore.cc',
 
         'apps/stupid-interest-generator.cc',
         'apps/stupid-interest-sink.cc',
@@ -44,6 +45,9 @@
         'model/ndn_timeoutheader.h',
         'model/ndn_nonceheader.h',
         'model/name-components.h',
+        #'model/ndn_hashhelper.h',
+        'model/ndn_contentstore.h',
+        'model/uthash.h',
         # 'helper/ndnabstraction-helper.h',
         'helper/ndn_stupidinterestgenerator_helper.h',