new file mode 100644
--- /dev/null
+++ b/assoc.c
@@ -0,0 +1,616 @@
+/* -*- Mode: C; tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*- */
+/*
+ * Hash table
+ *
+ * The hash function used here is by Bob Jenkins, 1996:
+ *    <http://burtleburtle.net/bob/hash/doobs.html>
+ *       "By Bob Jenkins, 1996.  bob_jenkins@burtleburtle.net.
+ *       You may use this code any way you wish, private, educational,
+ *       or commercial.  It's free."
+ *
+ * The rest of the file is licensed under the BSD license.  See LICENSE.
+ *
+ * $Id: assoc.c 551 2007-05-07 21:24:31Z plindner $
+ */
+
+#include "memcached.h"
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <sys/signal.h>
+#include <sys/resource.h>
+#include <fcntl.h>
+#include <netinet/in.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+/*
+ * Since the hash function does bit manipulation, it needs to know
+ * whether it's big or little-endian. ENDIAN_LITTLE and ENDIAN_BIG
+ * are set in the configure script.
+ */
+#if ENDIAN_BIG == 1
+# define HASH_LITTLE_ENDIAN 0
+# define HASH_BIG_ENDIAN 1
+#else
+# if ENDIAN_LITTLE == 1
+#  define HASH_LITTLE_ENDIAN 1
+#  define HASH_BIG_ENDIAN 0
+# else
+#  define HASH_LITTLE_ENDIAN 0
+#  define HASH_BIG_ENDIAN 0
+# endif
+#endif
+
+#define rot(x,k) (((x)<<(k)) ^ ((x)>>(32-(k))))
+
+/*
+-------------------------------------------------------------------------------
+mix -- mix 3 32-bit values reversibly.
+
+This is reversible, so any information in (a,b,c) before mix() is
+still in (a,b,c) after mix().
+
+If four pairs of (a,b,c) inputs are run through mix(), or through
+mix() in reverse, there are at least 32 bits of the output that
+are sometimes the same for one pair and different for another pair.
+This was tested for:
+* pairs that differed by one bit, by two bits, in any combination
+  of top bits of (a,b,c), or in any combination of bottom bits of
+  (a,b,c).
+* "differ" is defined as +, -, ^, or ~^.  For + and -, I transformed
+  the output delta to a Gray code (a^(a>>1)) so a string of 1's (as
+  is commonly produced by subtraction) look like a single 1-bit
+  difference.
+* the base values were pseudorandom, all zero but one bit set, or
+  all zero plus a counter that starts at zero.
+
+Some k values for my "a-=c; a^=rot(c,k); c+=b;" arrangement that
+satisfy this are
+    4  6  8 16 19  4
+    9 15  3 18 27 15
+   14  9  3  7 17  3
+Well, "9 15 3 18 27 15" didn't quite get 32 bits diffing
+for "differ" defined as + with a one-bit base and a two-bit delta.  I
+used http://burtleburtle.net/bob/hash/avalanche.html to choose
+the operations, constants, and arrangements of the variables.
+
+This does not achieve avalanche.  There are input bits of (a,b,c)
+that fail to affect some output bits of (a,b,c), especially of a.  The
+most thoroughly mixed value is c, but it doesn't really even achieve
+avalanche in c.
+
+This allows some parallelism.  Read-after-writes are good at doubling
+the number of bits affected, so the goal of mixing pulls in the opposite
+direction as the goal of parallelism.  I did what I could.  Rotates
+seem to cost as much as shifts on every machine I could lay my hands
+on, and rotates are much kinder to the top and bottom bits, so I used
+rotates.
+-------------------------------------------------------------------------------
+*/
+#define mix(a,b,c) \
+{ \
+  a -= c;  a ^= rot(c, 4);  c += b; \
+  b -= a;  b ^= rot(a, 6);  a += c; \
+  c -= b;  c ^= rot(b, 8);  b += a; \
+  a -= c;  a ^= rot(c,16);  c += b; \
+  b -= a;  b ^= rot(a,19);  a += c; \
+  c -= b;  c ^= rot(b, 4);  b += a; \
+}
+
+/*
+-------------------------------------------------------------------------------
+final -- final mixing of 3 32-bit values (a,b,c) into c
+
+Pairs of (a,b,c) values differing in only a few bits will usually
+produce values of c that look totally different.  This was tested for
+* pairs that differed by one bit, by two bits, in any combination
+  of top bits of (a,b,c), or in any combination of bottom bits of
+  (a,b,c).
+* "differ" is defined as +, -, ^, or ~^.  For + and -, I transformed
+  the output delta to a Gray code (a^(a>>1)) so a string of 1's (as
+  is commonly produced by subtraction) look like a single 1-bit
+  difference.
+* the base values were pseudorandom, all zero but one bit set, or
+  all zero plus a counter that starts at zero.
+
+These constants passed:
+ 14 11 25 16 4 14 24
+ 12 14 25 16 4 14 24
+and these came close:
+  4  8 15 26 3 22 24
+ 10  8 15 26 3 22 24
+ 11  8 15 26 3 22 24
+-------------------------------------------------------------------------------
+*/
+#define final(a,b,c) \
+{ \
+  c ^= b; c -= rot(b,14); \
+  a ^= c; a -= rot(c,11); \
+  b ^= a; b -= rot(a,25); \
+  c ^= b; c -= rot(b,16); \
+  a ^= c; a -= rot(c,4);  \
+  b ^= a; b -= rot(a,14); \
+  c ^= b; c -= rot(b,24); \
+}
+
+#if HASH_LITTLE_ENDIAN == 1
+uint32_t hash(
+  const void *key,       /* the key to hash */
+  size_t      length,    /* length of the key */
+  const uint32_t    initval)   /* initval */
+{
+  uint32_t a,b,c;                                          /* internal state */
+  union { const void *ptr; size_t i; } u;     /* needed for Mac Powerbook G4 */
+
+  /* Set up the internal state */
+  a = b = c = 0xdeadbeef + ((uint32_t)length) + initval;
+
+  u.ptr = key;
+  if (HASH_LITTLE_ENDIAN && ((u.i & 0x3) == 0)) {
+    const uint32_t *k = key;                           /* read 32-bit chunks */
+#ifdef VALGRIND
+    const uint8_t  *k8;
+#endif // ifdef VALGRIND
+
+    /*------ all but last block: aligned reads and affect 32 bits of (a,b,c) */
+    while (length > 12)
+    {
+      a += k[0];
+      b += k[1];
+      c += k[2];
+      mix(a,b,c);
+      length -= 12;
+      k += 3;
+    }
+
+    /*----------------------------- handle the last (probably partial) block */
+    /*
+     * "k[2]&0xffffff" actually reads beyond the end of the string, but
+     * then masks off the part it's not allowed to read.  Because the
+     * string is aligned, the masked-off tail is in the same word as the
+     * rest of the string.  Every machine with memory protection I've seen
+     * does it on word boundaries, so is OK with this.  But VALGRIND will
+     * still catch it and complain.  The masking trick does make the hash
+     * noticably faster for short strings (like English words).
+     */
+#ifndef VALGRIND
+
+    switch(length)
+    {
+    case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
+    case 11: c+=k[2]&0xffffff; b+=k[1]; a+=k[0]; break;
+    case 10: c+=k[2]&0xffff; b+=k[1]; a+=k[0]; break;
+    case 9 : c+=k[2]&0xff; b+=k[1]; a+=k[0]; break;
+    case 8 : b+=k[1]; a+=k[0]; break;
+    case 7 : b+=k[1]&0xffffff; a+=k[0]; break;
+    case 6 : b+=k[1]&0xffff; a+=k[0]; break;
+    case 5 : b+=k[1]&0xff; a+=k[0]; break;
+    case 4 : a+=k[0]; break;
+    case 3 : a+=k[0]&0xffffff; break;
+    case 2 : a+=k[0]&0xffff; break;
+    case 1 : a+=k[0]&0xff; break;
+    case 0 : return c;  /* zero length strings require no mixing */
+    }
+
+#else /* make valgrind happy */
+
+    k8 = (const uint8_t *)k;
+    switch(length)
+    {
+    case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
+    case 11: c+=((uint32_t)k8[10])<<16;  /* fall through */
+    case 10: c+=((uint32_t)k8[9])<<8;    /* fall through */
+    case 9 : c+=k8[8];                   /* fall through */
+    case 8 : b+=k[1]; a+=k[0]; break;
+    case 7 : b+=((uint32_t)k8[6])<<16;   /* fall through */
+    case 6 : b+=((uint32_t)k8[5])<<8;    /* fall through */
+    case 5 : b+=k8[4];                   /* fall through */
+    case 4 : a+=k[0]; break;
+    case 3 : a+=((uint32_t)k8[2])<<16;   /* fall through */
+    case 2 : a+=((uint32_t)k8[1])<<8;    /* fall through */
+    case 1 : a+=k8[0]; break;
+    case 0 : return c;  /* zero length strings require no mixing */
+    }
+
+#endif /* !valgrind */
+
+  } else if (HASH_LITTLE_ENDIAN && ((u.i & 0x1) == 0)) {
+    const uint16_t *k = key;                           /* read 16-bit chunks */
+    const uint8_t  *k8;
+
+    /*--------------- all but last block: aligned reads and different mixing */
+    while (length > 12)
+    {
+      a += k[0] + (((uint32_t)k[1])<<16);
+      b += k[2] + (((uint32_t)k[3])<<16);
+      c += k[4] + (((uint32_t)k[5])<<16);
+      mix(a,b,c);
+      length -= 12;
+      k += 6;
+    }
+
+    /*----------------------------- handle the last (probably partial) block */
+    k8 = (const uint8_t *)k;
+    switch(length)
+    {
+    case 12: c+=k[4]+(((uint32_t)k[5])<<16);
+             b+=k[2]+(((uint32_t)k[3])<<16);
+             a+=k[0]+(((uint32_t)k[1])<<16);
+             break;
+    case 11: c+=((uint32_t)k8[10])<<16;     /* @fallthrough */
+    case 10: c+=k[4];                       /* @fallthrough@ */
+             b+=k[2]+(((uint32_t)k[3])<<16);
+             a+=k[0]+(((uint32_t)k[1])<<16);
+             break;
+    case 9 : c+=k8[8];                      /* @fallthrough */
+    case 8 : b+=k[2]+(((uint32_t)k[3])<<16);
+             a+=k[0]+(((uint32_t)k[1])<<16);
+             break;
+    case 7 : b+=((uint32_t)k8[6])<<16;      /* @fallthrough */
+    case 6 : b+=k[2];
+             a+=k[0]+(((uint32_t)k[1])<<16);
+             break;
+    case 5 : b+=k8[4];                      /* @fallthrough */
+    case 4 : a+=k[0]+(((uint32_t)k[1])<<16);
+             break;
+    case 3 : a+=((uint32_t)k8[2])<<16;      /* @fallthrough */
+    case 2 : a+=k[0];
+             break;
+    case 1 : a+=k8[0];
+             break;
+    case 0 : return c;  /* zero length strings require no mixing */
+    }
+
+  } else {                        /* need to read the key one byte at a time */
+    const uint8_t *k = key;
+
+    /*--------------- all but the last block: affect some 32 bits of (a,b,c) */
+    while (length > 12)
+    {
+      a += k[0];
+      a += ((uint32_t)k[1])<<8;
+      a += ((uint32_t)k[2])<<16;
+      a += ((uint32_t)k[3])<<24;
+      b += k[4];
+      b += ((uint32_t)k[5])<<8;
+      b += ((uint32_t)k[6])<<16;
+      b += ((uint32_t)k[7])<<24;
+      c += k[8];
+      c += ((uint32_t)k[9])<<8;
+      c += ((uint32_t)k[10])<<16;
+      c += ((uint32_t)k[11])<<24;
+      mix(a,b,c);
+      length -= 12;
+      k += 12;
+    }
+
+    /*-------------------------------- last block: affect all 32 bits of (c) */
+    switch(length)                   /* all the case statements fall through */
+    {
+    case 12: c+=((uint32_t)k[11])<<24;
+    case 11: c+=((uint32_t)k[10])<<16;
+    case 10: c+=((uint32_t)k[9])<<8;
+    case 9 : c+=k[8];
+    case 8 : b+=((uint32_t)k[7])<<24;
+    case 7 : b+=((uint32_t)k[6])<<16;
+    case 6 : b+=((uint32_t)k[5])<<8;
+    case 5 : b+=k[4];
+    case 4 : a+=((uint32_t)k[3])<<24;
+    case 3 : a+=((uint32_t)k[2])<<16;
+    case 2 : a+=((uint32_t)k[1])<<8;
+    case 1 : a+=k[0];
+             break;
+    case 0 : return c;  /* zero length strings require no mixing */
+    }
+  }
+
+  final(a,b,c);
+  return c;             /* zero length strings require no mixing */
+}
+
+#elif HASH_BIG_ENDIAN == 1
+/*
+ * hashbig():
+ * This is the same as hashword() on big-endian machines.  It is different
+ * from hashlittle() on all machines.  hashbig() takes advantage of
+ * big-endian byte ordering.
+ */
+uint32_t hash( const void *key, size_t length, const uint32_t initval)
+{
+  uint32_t a,b,c;
+  union { const void *ptr; size_t i; } u; /* to cast key to (size_t) happily */
+
+  /* Set up the internal state */
+  a = b = c = 0xdeadbeef + ((uint32_t)length) + initval;
+
+  u.ptr = key;
+  if (HASH_BIG_ENDIAN && ((u.i & 0x3) == 0)) {
+    const uint32_t *k = key;                           /* read 32-bit chunks */
+#ifdef VALGRIND
+    const uint8_t  *k8;
+#endif // ifdef VALGRIND
+
+    /*------ all but last block: aligned reads and affect 32 bits of (a,b,c) */
+    while (length > 12)
+    {
+      a += k[0];
+      b += k[1];
+      c += k[2];
+      mix(a,b,c);
+      length -= 12;
+      k += 3;
+    }
+
+    /*----------------------------- handle the last (probably partial) block */
+    /*
+     * "k[2]<<8" actually reads beyond the end of the string, but
+     * then shifts out the part it's not allowed to read.  Because the
+     * string is aligned, the illegal read is in the same word as the
+     * rest of the string.  Every machine with memory protection I've seen
+     * does it on word boundaries, so is OK with this.  But VALGRIND will
+     * still catch it and complain.  The masking trick does make the hash
+     * noticably faster for short strings (like English words).
+     */
+#ifndef VALGRIND
+
+    switch(length)
+    {
+    case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
+    case 11: c+=k[2]&0xffffff00; b+=k[1]; a+=k[0]; break;
+    case 10: c+=k[2]&0xffff0000; b+=k[1]; a+=k[0]; break;
+    case 9 : c+=k[2]&0xff000000; b+=k[1]; a+=k[0]; break;
+    case 8 : b+=k[1]; a+=k[0]; break;
+    case 7 : b+=k[1]&0xffffff00; a+=k[0]; break;
+    case 6 : b+=k[1]&0xffff0000; a+=k[0]; break;
+    case 5 : b+=k[1]&0xff000000; a+=k[0]; break;
+    case 4 : a+=k[0]; break;
+    case 3 : a+=k[0]&0xffffff00; break;
+    case 2 : a+=k[0]&0xffff0000; break;
+    case 1 : a+=k[0]&0xff000000; break;
+    case 0 : return c;              /* zero length strings require no mixing */
+    }
+
+#else  /* make valgrind happy */
+
+    k8 = (const uint8_t *)k;
+    switch(length)                   /* all the case statements fall through */
+    {
+    case 12: c+=k[2]; b+=k[1]; a+=k[0]; break;
+    case 11: c+=((uint32_t)k8[10])<<8;  /* fall through */
+    case 10: c+=((uint32_t)k8[9])<<16;  /* fall through */
+    case 9 : c+=((uint32_t)k8[8])<<24;  /* fall through */
+    case 8 : b+=k[1]; a+=k[0]; break;
+    case 7 : b+=((uint32_t)k8[6])<<8;   /* fall through */
+    case 6 : b+=((uint32_t)k8[5])<<16;  /* fall through */
+    case 5 : b+=((uint32_t)k8[4])<<24;  /* fall through */
+    case 4 : a+=k[0]; break;
+    case 3 : a+=((uint32_t)k8[2])<<8;   /* fall through */
+    case 2 : a+=((uint32_t)k8[1])<<16;  /* fall through */
+    case 1 : a+=((uint32_t)k8[0])<<24; break;
+    case 0 : return c;
+    }
+
+#endif /* !VALGRIND */
+
+  } else {                        /* need to read the key one byte at a time */
+    const uint8_t *k = key;
+
+    /*--------------- all but the last block: affect some 32 bits of (a,b,c) */
+    while (length > 12)
+    {
+      a += ((uint32_t)k[0])<<24;
+      a += ((uint32_t)k[1])<<16;
+      a += ((uint32_t)k[2])<<8;
+      a += ((uint32_t)k[3]);
+      b += ((uint32_t)k[4])<<24;
+      b += ((uint32_t)k[5])<<16;
+      b += ((uint32_t)k[6])<<8;
+      b += ((uint32_t)k[7]);
+      c += ((uint32_t)k[8])<<24;
+      c += ((uint32_t)k[9])<<16;
+      c += ((uint32_t)k[10])<<8;
+      c += ((uint32_t)k[11]);
+      mix(a,b,c);
+      length -= 12;
+      k += 12;
+    }
+
+    /*-------------------------------- last block: affect all 32 bits of (c) */
+    switch(length)                   /* all the case statements fall through */
+    {
+    case 12: c+=k[11];
+    case 11: c+=((uint32_t)k[10])<<8;
+    case 10: c+=((uint32_t)k[9])<<16;
+    case 9 : c+=((uint32_t)k[8])<<24;
+    case 8 : b+=k[7];
+    case 7 : b+=((uint32_t)k[6])<<8;
+    case 6 : b+=((uint32_t)k[5])<<16;
+    case 5 : b+=((uint32_t)k[4])<<24;
+    case 4 : a+=k[3];
+    case 3 : a+=((uint32_t)k[2])<<8;
+    case 2 : a+=((uint32_t)k[1])<<16;
+    case 1 : a+=((uint32_t)k[0])<<24;
+             break;
+    case 0 : return c;
+    }
+  }
+
+  final(a,b,c);
+  return c;
+}
+#else // HASH_XXX_ENDIAN == 1
+#error Must define HASH_BIG_ENDIAN or HASH_LITTLE_ENDIAN
+#endif // hash_XXX_ENDIAN == 1
+
+typedef  unsigned long  int  ub4;   /* unsigned 4-byte quantities */
+typedef  unsigned       char ub1;   /* unsigned 1-byte quantities */
+
+/* how many powers of 2's worth of buckets we use */
+static int hashpower = 16;
+
+#define hashsize(n) ((ub4)1<<(n))
+#define hashmask(n) (hashsize(n)-1)
+
+/* Main hash table. This is where we look except during expansion. */
+static item** primary_hashtable = 0;
+
+/*
+ * Previous hash table. During expansion, we look here for keys that haven't
+ * been moved over to the primary yet.
+ */
+static item** old_hashtable = 0;
+
+/* Number of items in the hash table. */
+static int hash_items = 0;
+
+/* Flag: Are we in the middle of expanding now? */
+static int expanding = 0;
+
+/*
+ * During expansion we migrate values with bucket granularity; this is how
+ * far we've gotten so far. Ranges from 0 .. hashsize(hashpower - 1) - 1.
+ */
+static int expand_bucket = 0;
+
+void assoc_init(void) {
+    unsigned int hash_size = hashsize(hashpower) * sizeof(void*);
+    primary_hashtable = malloc(hash_size);
+    if (! primary_hashtable) {
+        fprintf(stderr, "Failed to init hashtable.\n");
+        exit(EXIT_FAILURE);
+    }
+    memset(primary_hashtable, 0, hash_size);
+}
+
+item *assoc_find(const char *key, const size_t nkey) {
+    uint32_t hv = hash(key, nkey, 0);
+    item *it;
+    int oldbucket;
+
+    if (expanding &&
+        (oldbucket = (hv & hashmask(hashpower - 1))) >= expand_bucket)
+    {
+        it = old_hashtable[oldbucket];
+    } else {
+        it = primary_hashtable[hv & hashmask(hashpower)];
+    }
+
+    while (it) {
+        if ((nkey == it->nkey) &&
+            (memcmp(key, ITEM_key(it), nkey) == 0)) {
+            return it;
+        }
+        it = it->h_next;
+    }
+    return 0;
+}
+
+/* returns the address of the item pointer before the key.  if *item == 0,
+   the item wasn't found */
+
+static item** _hashitem_before (const char *key, const size_t nkey) {
+    uint32_t hv = hash(key, nkey, 0);
+    item **pos;
+    int oldbucket;
+
+    if (expanding &&
+        (oldbucket = (hv & hashmask(hashpower - 1))) >= expand_bucket)
+    {
+        pos = &old_hashtable[oldbucket];
+    } else {
+        pos = &primary_hashtable[hv & hashmask(hashpower)];
+    }
+
+    while (*pos && ((nkey != (*pos)->nkey) || memcmp(key, ITEM_key(*pos), nkey))) {
+        pos = &(*pos)->h_next;
+    }
+    return pos;
+}
+
+/* grows the hashtable to the next power of 2. */
+static void assoc_expand(void) {
+    old_hashtable = primary_hashtable;
+
+    primary_hashtable = calloc(hashsize(hashpower + 1), sizeof(void *));
+    if (primary_hashtable) {
+        if (settings.verbose > 1)
+            fprintf(stderr, "Hash table expansion starting\n");
+        hashpower++;
+        expanding = 1;
+        expand_bucket = 0;
+        do_assoc_move_next_bucket();
+    } else {
+        primary_hashtable = old_hashtable;
+        /* Bad news, but we can keep running. */
+    }
+}
+
+/* migrates the next bucket to the primary hashtable if we're expanding. */
+void do_assoc_move_next_bucket(void) {
+    item *it, *next;
+    int bucket;
+
+    if (expanding) {
+        for (it = old_hashtable[expand_bucket]; NULL != it; it = next) {
+            next = it->h_next;
+
+            bucket = hash(ITEM_key(it), it->nkey, 0) & hashmask(hashpower);
+            it->h_next = primary_hashtable[bucket];
+            primary_hashtable[bucket] = it;
+        }
+
+        old_hashtable[expand_bucket] = NULL;
+
+        expand_bucket++;
+        if (expand_bucket == hashsize(hashpower - 1)) {
+            expanding = 0;
+            free(old_hashtable);
+            if (settings.verbose > 1)
+                fprintf(stderr, "Hash table expansion done\n");
+        }
+    }
+}
+
+/* Note: this isn't an assoc_update.  The key must not already exist to call this */
+int assoc_insert(item *it) {
+    uint32_t hv;
+    int oldbucket;
+
+    assert(assoc_find(ITEM_key(it), it->nkey) == 0);  /* shouldn't have duplicately named things defined */
+
+    hv = hash(ITEM_key(it), it->nkey, 0);
+    if (expanding &&
+        (oldbucket = (hv & hashmask(hashpower - 1))) >= expand_bucket)
+    {
+        it->h_next = old_hashtable[oldbucket];
+        old_hashtable[oldbucket] = it;
+    } else {
+        it->h_next = primary_hashtable[hv & hashmask(hashpower)];
+        primary_hashtable[hv & hashmask(hashpower)] = it;
+    }
+
+    hash_items++;
+    if (! expanding && hash_items > (hashsize(hashpower) * 3) / 2) {
+        assoc_expand();
+    }
+
+    return 1;
+}
+
+void assoc_delete(const char *key, const size_t nkey) {
+    item **before = _hashitem_before(key, nkey);
+
+    if (*before) {
+        item *nxt = (*before)->h_next;
+        (*before)->h_next = 0;   /* probably pointless, but whatever. */
+        *before = nxt;
+        hash_items--;
+        return;
+    }
+    /* Note:  we never actually get here.  the callers don't delete things
+       they can't find. */
+    assert(*before != 0);
+}