Replace balanced trees with hash tables: this should make stuff significantly faster.

svn:r5441

src/common/Makefile.am

@@ -6,4 +6,4 @@ noinst_LIBRARIES = libor.a libor-crypto.a
 libor_a_SOURCES = log.c util.c compat.c container.c
 libor_crypto_a_SOURCES = crypto.c aes.c tortls.c torgzip.c
 
-noinst_HEADERS = log.h crypto.h test.h util.h compat.h aes.h torint.h tortls.h strlcpy.c strlcat.c torgzip.h container.h
+noinst_HEADERS = log.h crypto.h test.h util.h compat.h aes.h torint.h tortls.h strlcpy.c strlcat.c torgzip.h container.h ht.h

src/common/container.c

@@ -14,7 +14,6 @@ const char container_c_id[] = "$Id$";
 #include "compat.h"
 #include "util.h"
 #include "log.h"
-#include "../or/tree.h"
 #include "container.h"
 #include "crypto.h"
 
@@ -25,6 +24,8 @@ const char container_c_id[] = "$Id$";
 #include <string.h>
 #include <assert.h>
 
+#include "ht.h"
+
 /* All newly allocated smartlists have this capacity.
  */
 #define SMARTLIST_DEFAULT_CAPACITY 32
@@ -445,40 +446,53 @@ smartlist_sort_strings(smartlist_t *sl)
 
 #define DEFINE_MAP_STRUCTS(maptype, keydecl, prefix)      \
   typedef struct prefix ## entry_t {                      \
-    SPLAY_ENTRY(prefix ## entry_t) node;                  \
+    HT_ENTRY(prefix ## entry_t) node;                     \
     keydecl;                                              \
     void *val;                                            \
   } prefix ## entry_t;                                    \
   struct maptype {                                        \
-    SPLAY_HEAD(prefix ## tree, prefix ## entry_t) head;   \
+    HT_HEAD(prefix ## tree, prefix ## entry_t) head;      \
   };
 
 DEFINE_MAP_STRUCTS(strmap_t, char *key, strmap_);
 DEFINE_MAP_STRUCTS(digestmap_t, char key[DIGEST_LEN], digestmap_);
 
 /** Helper: compare strmap_t_entry objects by key value. */
-static int
-compare_strmap_entries(strmap_entry_t *a,
-                       strmap_entry_t *b)
+static INLINE int
+strmap_entries_eq(strmap_entry_t *a, strmap_entry_t *b)
+{
+  return !strcmp(a->key, b->key);
+}
+
+static INLINE unsigned int
+strmap_entry_hash(strmap_entry_t *a)
 {
-  return strcmp(a->key, b->key);
+  return ht_string_hash(a->key);
 }
 
 /** Helper: compare digestmap_entry_t objects by key value. */
-static int
-compare_digestmap_entries(digestmap_entry_t *a,
-                          digestmap_entry_t *b)
+static INLINE int
+digestmap_entries_eq(digestmap_entry_t *a, digestmap_entry_t *b)
 {
-  return memcmp(a->key, b->key, DIGEST_LEN);
+  return !memcmp(a->key, b->key, DIGEST_LEN);
 }
 
-SPLAY_PROTOTYPE(strmap_tree, strmap_entry_t, node, compare_strmap_entries);
-SPLAY_GENERATE(strmap_tree, strmap_entry_t, node, compare_strmap_entries);
+static INLINE unsigned int
+digestmap_entry_hash(digestmap_entry_t *a)
+{
+  uint32_t *p = (uint32_t*)a->key;
+  return ht_improve_hash(p[0] ^ p[1] ^ p[2] ^ p[3] ^ p[4]);
+}
+
+HT_PROTOTYPE(strmap_tree, strmap_entry_t, node, strmap_entry_hash,
+             strmap_entries_eq);
+HT_GENERATE(strmap_tree, strmap_entry_t, node, strmap_entry_hash,
+            strmap_entries_eq, 0.6, malloc, realloc, free);
 
-SPLAY_PROTOTYPE(digestmap_tree, digestmap_entry_t, node,
-                compare_digestmap_entries);
-SPLAY_GENERATE(digestmap_tree, digestmap_entry_t, node,
-               compare_digestmap_entries);
+HT_PROTOTYPE(digestmap_tree, digestmap_entry_t, node, digestmap_entry_hash,
+             digestmap_entries_eq);
+HT_GENERATE(digestmap_tree, digestmap_entry_t, node, digestmap_entry_hash,
+            digestmap_entries_eq, 0.6, malloc, realloc, free);
 
 /** Constructor to create a new empty map from strings to void*'s.
  */
@@ -487,7 +501,7 @@ strmap_new(void)
 {
   strmap_t *result;
   result = tor_malloc(sizeof(strmap_t));
-  SPLAY_INIT(&result->head);
+  HT_INIT(&result->head);
   return result;
 }
 
@@ -498,7 +512,7 @@ digestmap_new(void)
 {
   digestmap_t *result;
   result = tor_malloc(sizeof(digestmap_t));
-  SPLAY_INIT(&result->head);
+  HT_INIT(&result->head);
   return result;
 }
 
@@ -518,7 +532,7 @@ strmap_set(strmap_t *map, const char *key, void *val)
   tor_assert(key);
   tor_assert(val);
   search.key = (char*)key;
-  resolve = SPLAY_FIND(strmap_tree, &map->head, &search);
+  resolve = HT_FIND(strmap_tree, &map->head, &search);
   if (resolve) {
     oldval = resolve->val;
     resolve->val = val;
@@ -527,7 +541,8 @@ strmap_set(strmap_t *map, const char *key, void *val)
     resolve = tor_malloc_zero(sizeof(strmap_entry_t));
     resolve->key = tor_strdup(key);
     resolve->val = val;
-    SPLAY_INSERT(strmap_tree, &map->head, resolve);
+    tor_assert(!HT_FIND(strmap_tree, &map->head, resolve));
+    HT_INSERT(strmap_tree, &map->head, resolve);
     return NULL;
   }
 }
@@ -543,7 +558,7 @@ digestmap_set(digestmap_t *map, const char *key, void *val)
   tor_assert(key);
   tor_assert(val);
   memcpy(&search.key, key, DIGEST_LEN);
-  resolve = SPLAY_FIND(digestmap_tree, &map->head, &search);
+  resolve = HT_FIND(digestmap_tree, &map->head, &search);
   if (resolve) {
     oldval = resolve->val;
     resolve->val = val;
@@ -552,7 +567,7 @@ digestmap_set(digestmap_t *map, const char *key, void *val)
     resolve = tor_malloc_zero(sizeof(digestmap_entry_t));
     memcpy(resolve->key, key, DIGEST_LEN);
     resolve->val = val;
-    SPLAY_INSERT(digestmap_tree, &map->head, resolve);
+    HT_INSERT(digestmap_tree, &map->head, resolve);
     return NULL;
   }
 }
@@ -568,7 +583,7 @@ strmap_get(strmap_t *map, const char *key)
   tor_assert(map);
   tor_assert(key);
   search.key = (char*)key;
-  resolve = SPLAY_FIND(strmap_tree, &map->head, &search);
+  resolve = HT_FIND(strmap_tree, &map->head, &search);
   if (resolve) {
     return resolve->val;
   } else {
@@ -585,7 +600,7 @@ digestmap_get(digestmap_t *map, const char *key)
   tor_assert(map);
   tor_assert(key);
   memcpy(&search.key, key, DIGEST_LEN);
-  resolve = SPLAY_FIND(digestmap_tree, &map->head, &search);
+  resolve = HT_FIND(digestmap_tree, &map->head, &search);
   if (resolve) {
     return resolve->val;
   } else {
@@ -608,10 +623,9 @@ strmap_remove(strmap_t *map, const char *key)
   tor_assert(map);
   tor_assert(key);
   search.key = (char*)key;
-  resolve = SPLAY_FIND(strmap_tree, &map->head, &search);
+  resolve = HT_REMOVE(strmap_tree, &map->head, &search);
   if (resolve) {
     oldval = resolve->val;
-    SPLAY_REMOVE(strmap_tree, &map->head, resolve);
     tor_free(resolve->key);
     tor_free(resolve);
     return oldval;
@@ -630,10 +644,9 @@ digestmap_remove(digestmap_t *map, const char *key)
   tor_assert(map);
   tor_assert(key);
   memcpy(&search.key, key, DIGEST_LEN);
-  resolve = SPLAY_FIND(digestmap_tree, &map->head, &search);
+  resolve = HT_REMOVE(digestmap_tree, &map->head, &search);
   if (resolve) {
     oldval = resolve->val;
-    SPLAY_REMOVE(digestmap_tree, &map->head, resolve);
     tor_free(resolve);
     return oldval;
   } else {
@@ -679,53 +692,6 @@ strmap_remove_lc(strmap_t *map, const char *key)
   return v;
 }
 
-/** Invoke fn() on every entry of the map, in order.  For every entry,
- * fn() is invoked with that entry's key, that entry's value, and the
- * value of <b>data</b> supplied to strmap_foreach.  fn() must return a new
- * (possibly unmodified) value for each entry: if fn() returns NULL, the
- * entry is removed.
- *
- * Example:
- * \code
- *   static void* upcase_and_remove_empty_vals(const char *key, void *val,
- *                                             void* data) {
- *     char *cp = (char*)val;
- *     if (!*cp) {  // val is an empty string.
- *       free(val);
- *       return NULL;
- *     } else {
- *       for (; *cp; cp++)
- *         *cp = toupper(*cp);
- *       }
- *       return val;
- *     }
- *   }
- *
- *   ...
- *
- *   strmap_foreach(map, upcase_and_remove_empty_vals, NULL);
- * \endcode
- */
-void
-strmap_foreach(strmap_t *map,
-               void* (*fn)(const char *key, void *val, void *data),
-               void *data)
-{
-  strmap_entry_t *ptr, *next;
-  tor_assert(map);
-  tor_assert(fn);
-  for (ptr = SPLAY_MIN(strmap_tree, &map->head); ptr != NULL; ptr = next) {
-    /* This remove-in-place usage is specifically blessed in tree(3). */
-    next = SPLAY_NEXT(strmap_tree, &map->head, ptr);
-    ptr->val = fn(ptr->key, ptr->val, data);
-    if (!ptr->val) {
-      SPLAY_REMOVE(strmap_tree, &map->head, ptr);
-      tor_free(ptr->key);
-      tor_free(ptr);
-    }
-  }
-}
-
 /** return an <b>iterator</b> pointer to the front of a map.
  *
  * Iterator example:
@@ -756,14 +722,14 @@ strmap_iter_t *
 strmap_iter_init(strmap_t *map)
 {
   tor_assert(map);
-  return SPLAY_MIN(strmap_tree, &map->head);
+  return HT_START(strmap_tree, &map->head);
 }
 
 digestmap_iter_t *
 digestmap_iter_init(digestmap_t *map)
 {
   tor_assert(map);
-  return SPLAY_MIN(digestmap_tree, &map->head);
+  return HT_START(digestmap_tree, &map->head);
 }
 
 /** Advance the iterator <b>iter</b> for map a single step to the next entry.
@@ -773,7 +739,7 @@ strmap_iter_next(strmap_t *map, strmap_iter_t *iter)
 {
   tor_assert(map);
   tor_assert(iter);
-  return SPLAY_NEXT(strmap_tree, &map->head, iter);
+  return HT_NEXT(strmap_tree, &map->head, iter);
 }
 
 digestmap_iter_t *
@@ -781,7 +747,7 @@ digestmap_iter_next(digestmap_t *map, digestmap_iter_t *iter)
 {
   tor_assert(map);
   tor_assert(iter);
-  return SPLAY_NEXT(digestmap_tree, &map->head, iter);
+  return HT_NEXT(digestmap_tree, &map->head, iter);
 }
 
 /** Advance the iterator <b>iter</b> a single step to the next entry, removing
@@ -793,10 +759,9 @@ strmap_iter_next_rmv(strmap_t *map, strmap_iter_t *iter)
   strmap_iter_t *next;
   tor_assert(map);
   tor_assert(iter);
-  next = SPLAY_NEXT(strmap_tree, &map->head, iter);
-  SPLAY_REMOVE(strmap_tree, &map->head, iter);
-  tor_free(iter->key);
-  tor_free(iter);
+  next = HT_NEXT_RMV(strmap_tree, &map->head, iter);
+  tor_free((*iter)->key);
+  tor_free(*iter);
   return next;
 }
 
@@ -806,9 +771,8 @@ digestmap_iter_next_rmv(digestmap_t *map, digestmap_iter_t *iter)
   digestmap_iter_t *next;
   tor_assert(map);
   tor_assert(iter);
-  next = SPLAY_NEXT(digestmap_tree, &map->head, iter);
-  SPLAY_REMOVE(digestmap_tree, &map->head, iter);
-  tor_free(iter);
+  next = HT_NEXT_RMV(digestmap_tree, &map->head, iter);
+  tor_free(*iter);
   return next;
 }
 
@@ -820,8 +784,8 @@ strmap_iter_get(strmap_iter_t *iter, const char **keyp, void **valp)
   tor_assert(iter);
   tor_assert(keyp);
   tor_assert(valp);
-  *keyp = iter->key;
-  *valp = iter->val;
+  *keyp = (*iter)->key;
+  *valp = (*iter)->val;
 }
 
 void
@@ -830,8 +794,8 @@ digestmap_iter_get(digestmap_iter_t *iter, const char **keyp, void **valp)
   tor_assert(iter);
   tor_assert(keyp);
   tor_assert(valp);
-  *keyp = iter->key;
-  *valp = iter->val;
+  *keyp = (*iter)->key;
+  *valp = (*iter)->val;
 }
 
 /** Return true iff iter has advanced past the last entry of map.
@@ -853,30 +817,32 @@ digestmap_iter_done(digestmap_iter_t *iter)
 void
 strmap_free(strmap_t *map, void (*free_val)(void*))
 {
-  strmap_entry_t *ent, *next;
-  for (ent = SPLAY_MIN(strmap_tree, &map->head); ent != NULL; ent = next) {
-    next = SPLAY_NEXT(strmap_tree, &map->head, ent);
-    SPLAY_REMOVE(strmap_tree, &map->head, ent);
-    tor_free(ent->key);
+  strmap_entry_t **ent, **next, *this;
+  for (ent = HT_START(strmap_tree, &map->head); ent != NULL; ent = next) {
+    this = *ent;
+    next = HT_NEXT_RMV(strmap_tree, &map->head, ent);
+    tor_free(this->key);
     if (free_val)
-      free_val(ent->val);
-    tor_free(ent);
+      free_val(this->val);
+    tor_free(this);
   }
-  tor_assert(SPLAY_EMPTY(&map->head));
+  tor_assert(HT_EMPTY(&map->head));
+  HT_CLEAR(strmap_tree, &map->head);
   tor_free(map);
 }
 void
 digestmap_free(digestmap_t *map, void (*free_val)(void*))
 {
-  digestmap_entry_t *ent, *next;
-  for (ent = SPLAY_MIN(digestmap_tree, &map->head); ent != NULL; ent = next) {
-    next = SPLAY_NEXT(digestmap_tree, &map->head, ent);
-    SPLAY_REMOVE(digestmap_tree, &map->head, ent);
+  digestmap_entry_t **ent, **next, *this;
+  for (ent = HT_START(digestmap_tree, &map->head); ent != NULL; ent = next) {
+    this = *ent;
+    next = HT_NEXT_RMV(digestmap_tree, &map->head, ent);
     if (free_val)
-      free_val(ent->val);
-    tor_free(ent);
+      free_val(this->val);
+    tor_free(this);
   }
-  tor_assert(SPLAY_EMPTY(&map->head));
+  tor_assert(HT_EMPTY(&map->head));
+  HT_CLEAR(digestmap_tree, &map->head);
   tor_free(map);
 }
 
@@ -884,12 +850,12 @@ digestmap_free(digestmap_t *map, void (*free_val)(void*))
 int
 strmap_isempty(strmap_t *map)
 {
-  return SPLAY_EMPTY(&map->head);
+  return HT_EMPTY(&map->head);
 }
 
 int
 digestmap_isempty(digestmap_t *map)
 {
-  return SPLAY_EMPTY(&map->head);
+  return HT_EMPTY(&map->head);
 }
 

src/common/container.h

@@ -110,13 +110,11 @@ char *smartlist_join_strings2(smartlist_t *sl, const char *join,
 
 #define DECLARE_MAP_FNS(maptype, keytype, prefix)                       \
   typedef struct maptype maptype;                                       \
-  typedef struct prefix##entry_t prefix##iter_t;                        \
+  typedef struct prefix##entry_t *prefix##iter_t;                       \
   maptype* prefix##new(void);                                           \
   void* prefix##set(maptype *map, keytype key, void *val);              \
   void* prefix##get(maptype *map, keytype key);                         \
   void* prefix##remove(maptype *map, keytype key);                      \
-  typedef void* (*prefix##foreach_fn)(keytype key, void *val, void *data); \
-  void prefix##foreach(maptype *map, prefix##foreach_fn fn, void *data); \
   void prefix##free(maptype *map, void (*free_val)(void*));             \
   int prefix##isempty(maptype *map);                                    \
   prefix##iter_t *prefix##iter_init(maptype *map);                      \

src/or/circuitlist.c

@@ -12,10 +12,7 @@ const char circuitlist_c_id[] = "$Id$";
 
 #include "or.h"
 
-/* Define RB_AUGMENT to avoid warnings about if statements with emtpy bodies.
- */
-#define RB_AUGMENT(x) do{}while(0)
-#include "tree.h"
+#include "../common/ht.h"
 
 /********* START VARIABLES **********/
 
@@ -31,30 +28,34 @@ static void circuit_free_cpath_node(crypt_path_t *victim);
 /** A map from OR connection and circuit ID to circuit.  (Lookup performance is
  * very important here, since we need to do it every time a cell arrives.) */
 typedef struct orconn_circid_circuit_map_t {
-  RB_ENTRY(orconn_circid_circuit_map_t) node;
+  HT_ENTRY(orconn_circid_circuit_map_t) node;
   connection_t *or_conn;
   uint16_t circ_id;
   circuit_t *circuit;
 } orconn_circid_circuit_map_t;
 
-/** Helper for RB tree: compare the OR connection and circuit ID for a and b,
+/** Helper for hash tables: compare the OR connection and circuit ID for a and b,
  * and return less than, equal to, or greater than zero appropriately.
  */
 static INLINE int
-compare_orconn_circid_entries(orconn_circid_circuit_map_t *a,
-                              orconn_circid_circuit_map_t *b)
+_orconn_circid_entries_eq(orconn_circid_circuit_map_t *a,
+                          orconn_circid_circuit_map_t *b)
 {
-  if (a->or_conn < b->or_conn)
-    return -1;
-  else if (a->or_conn > b->or_conn)
-    return 1;
-  else
-    return ((int)b->circ_id) - ((int)a->circ_id);
-};
+  return a->or_conn == b->or_conn && a->circ_id == b->circ_id;
+}
+
+static INLINE unsigned int
+_orconn_circid_entry_hash(orconn_circid_circuit_map_t *a)
+{
+  return (((unsigned)a->circ_id)<<16) ^ (unsigned)(uintptr_t)(a->or_conn);
+}
 
-static RB_HEAD(orconn_circid_tree, orconn_circid_circuit_map_t) orconn_circid_circuit_map = RB_INITIALIZER(orconn_circid_circuit_map);
-RB_PROTOTYPE(orconn_circid_tree, orconn_circid_circuit_map_t, node, compare_orconn_circid_entries);
-RB_GENERATE(orconn_circid_tree, orconn_circid_circuit_map_t, node, compare_orconn_circid_entries);
+static HT_HEAD(orconn_circid_tree, orconn_circid_circuit_map_t) orconn_circid_circuit_map = HT_INITIALIZER();
+HT_PROTOTYPE(orconn_circid_tree, orconn_circid_circuit_map_t, node,
+             _orconn_circid_entry_hash, _orconn_circid_entries_eq);
+HT_GENERATE(orconn_circid_tree, orconn_circid_circuit_map_t, node,
+            _orconn_circid_entry_hash, _orconn_circid_entries_eq, 0.6,
+            malloc, realloc, free);
 
 /** The most recently returned entry from circuit_get_by_circid_orconn;
  * used to improve performance when many cells arrive in a row from the
@@ -102,11 +103,10 @@ circuit_set_circid_orconn(circuit_t *circ, uint16_t id,
   if (old_conn) { /* we may need to remove it from the conn-circid map */
     search.circ_id = old_id;
     search.or_conn = old_conn;
-    found = RB_FIND(orconn_circid_tree, &orconn_circid_circuit_map, &search);
+    found = HT_REMOVE(orconn_circid_tree, &orconn_circid_circuit_map, &search);
     if (found) {
-      RB_REMOVE(orconn_circid_tree, &orconn_circid_circuit_map, found);
+      tor_free(found);
     }
-    tor_free(found);
   }
 
   if (conn == NULL)
@@ -115,7 +115,7 @@ circuit_set_circid_orconn(circuit_t *circ, uint16_t id,
   /* now add the new one to the conn-circid map */
   search.circ_id = id;
   search.or_conn = conn;
-  found = RB_FIND(orconn_circid_tree, &orconn_circid_circuit_map, &search);
+  found = HT_FIND(orconn_circid_tree, &orconn_circid_circuit_map, &search);
   if (found) {
     found->circuit = circ;
   } else {
@@ -123,7 +123,7 @@ circuit_set_circid_orconn(circuit_t *circ, uint16_t id,
     found->circ_id = id;
     found->or_conn = conn;
     found->circuit = circ;
-    RB_INSERT(orconn_circid_tree, &orconn_circid_circuit_map, found);
+    HT_INSERT(orconn_circid_tree, &orconn_circid_circuit_map, found);
   }
 }
 
@@ -358,7 +358,7 @@ circuit_get_by_circid_orconn_impl(uint16_t circ_id, connection_t *conn)
   } else {
     search.circ_id = circ_id;
     search.or_conn = conn;
-    found = RB_FIND(orconn_circid_tree, &orconn_circid_circuit_map, &search);
+    found = HT_FIND(orconn_circid_tree, &orconn_circid_circuit_map, &search);
     _last_circid_orconn_ent = found;
   }
   if (found && found->circuit)

src/or/connection_edge.c

@@ -890,8 +890,8 @@ addressmap_get_mappings(smartlist_t *sl, time_t min_expires, time_t max_expires)
      val = _val;
      if (val->expires >= min_expires && val->expires <= max_expires) {
        if (!sl) {
-         addressmap_ent_remove(key, val);
          iter = strmap_iter_next_rmv(addressmap,iter);
+         addressmap_ent_remove(key, val);
          continue;
        } else if (val->new_address) {
          size_t len = strlen(key)+strlen(val->new_address)+2;

src/or/dns.c

@@ -18,7 +18,7 @@ const char dns_c_id[] = "$Id$";
  */
 
 #include "or.h"
-#include "tree.h"
+#include "../common/ht.h"
 
 /** Longest hostname we're willing to resolve. */
 #define MAX_ADDRESSLEN 256
@@ -55,7 +55,7 @@ typedef struct pending_connection_t {
  * list from oldest to newest.
  */
 typedef struct cached_resolve_t {
-  SPLAY_ENTRY(cached_resolve_t) node;
+  HT_ENTRY(cached_resolve_t) node;
   char address[MAX_ADDRESSLEN]; /**< The hostname to be resolved. */
   uint32_t addr; /**< IPv4 addr for <b>address</b>. */
   char state; /**< 0 is pending; 1 means answer is valid; 2 means resolve failed. */
@@ -77,26 +77,33 @@ static int spawn_enough_dnsworkers(void);
 static void send_resolved_cell(connection_t *conn, uint8_t answer_type);
 
 /** Splay tree of cached_resolve objects. */
-static SPLAY_HEAD(cache_tree, cached_resolve_t) cache_root;
+static HT_HEAD(cache_tree, cached_resolve_t) cache_root;
 
 /** Function to compare hashed resolves on their addresses; used to
  * implement splay trees. */
-static int
-compare_cached_resolves(cached_resolve_t *a,
-                        cached_resolve_t *b)
+static INLINE int
+cached_resolves_eq(cached_resolve_t *a, cached_resolve_t *b)
 {
   /* make this smarter one day? */
-  return strncmp(a->address, b->address, MAX_ADDRESSLEN);
+  return !strncmp(a->address, b->address, MAX_ADDRESSLEN);
+}
+
+static INLINE unsigned int
+cached_resolve_hash(cached_resolve_t *a)
+{
+  return ht_string_hash(a->address);
 }
 
-SPLAY_PROTOTYPE(cache_tree, cached_resolve_t, node, compare_cached_resolves);
-SPLAY_GENERATE(cache_tree, cached_resolve_t, node, compare_cached_resolves);
+HT_PROTOTYPE(cache_tree, cached_resolve_t, node, cached_resolve_hash,
+             cached_resolves_eq);
+HT_GENERATE(cache_tree, cached_resolve_t, node, cached_resolve_hash,
+            cached_resolves_eq, 0.6, malloc, realloc, free);
 
 /** Initialize the DNS cache. */
 static void
 init_cache_tree(void)
 {
-  SPLAY_INIT(&cache_root);
+  HT_INIT(&cache_root);
 }
 
 /** Initialize the DNS subsystem; called by the OR process. */
@@ -123,12 +130,13 @@ _free_cached_resolve(cached_resolve_t *r)
 void
 dns_free_all(void)
 {
-  cached_resolve_t *ptr, *next;
-  for (ptr = SPLAY_MIN(cache_tree, &cache_root); ptr != NULL; ptr = next) {
-    next = SPLAY_NEXT(cache_tree, &cache_root, ptr);
-    SPLAY_REMOVE(cache_tree, &cache_root, ptr);
-    _free_cached_resolve(ptr);
+  cached_resolve_t **ptr, **next, *item;
+  for (ptr = HT_START(cache_tree, &cache_root); ptr != NULL; ptr = next) {
+    item = *ptr;
+    next = HT_NEXT_RMV(cache_tree, &cache_root, ptr);
+    _free_cached_resolve(item);
   }
+  HT_CLEAR(cache_tree, &cache_root);
 }
 
 /** Linked list of resolved addresses, oldest to newest. */
@@ -174,7 +182,7 @@ purge_expired_resolves(uint32_t now)
     oldest_cached_resolve = resolve->next;
     if (!oldest_cached_resolve) /* if there are no more, */
       newest_cached_resolve = NULL; /* then make sure the list's tail knows that too */
-    SPLAY_REMOVE(cache_tree, &cache_root, resolve);
+    HT_REMOVE(cache_tree, &cache_root, resolve);
     tor_free(resolve);
   }
 }
@@ -230,7 +238,7 @@ insert_resolve(cached_resolve_t *r)
   }
   newest_cached_resolve = r;
 
-  SPLAY_INSERT(cache_tree, &cache_root, r);
+  HT_INSERT(cache_tree, &cache_root, r);
 }
 
 /** See if we have a cache entry for <b>exitconn</b>-\>address. if so,
@@ -273,7 +281,7 @@ dns_resolve(connection_t *exitconn)
 
   /* now check the tree to see if 'address' is already there. */
   strlcpy(search.address, exitconn->address, sizeof(search.address));
-  resolve = SPLAY_FIND(cache_tree, &cache_root, &search);
+  resolve = HT_FIND(cache_tree, &cache_root, &search);
   if (resolve) { /* already there */
     switch (resolve->state) {
       case CACHE_STATE_PENDING:
@@ -383,7 +391,7 @@ connection_dns_remove(connection_t *conn)
 
   strlcpy(search.address, conn->address, sizeof(search.address));
 
-  resolve = SPLAY_FIND(cache_tree, &cache_root, &search);
+  resolve = HT_FIND(cache_tree, &cache_root, &search);
   if (!resolve) {
     /* XXXX RD This *is* a bug, right? -NM */
     notice(LD_BUG,"Address '%s' is not pending. Dropping.", safe_str(conn->address));
@@ -422,10 +430,10 @@ void
 assert_connection_edge_not_dns_pending(connection_t *conn)
 {
   pending_connection_t *pend;