connection cache: avoid Curl_hash_alloc()

... by using plain structs instead of pointers for the connection cache,
we can avoid several dynamic allocations that weren't necessary.

lib/conncache.c

@@ -45,32 +45,16 @@ static void free_bundle_hash_entry(void *freethis)
   Curl_bundle_destroy(b);
 }
 
-struct conncache *Curl_conncache_init(int size)
+int Curl_conncache_init(struct conncache *connc, int size)
 {
-  struct conncache *connc;
-
-  connc = calloc(1, sizeof(struct conncache));
-  if(!connc)
-    return NULL;
-
-  connc->hash = Curl_hash_alloc(size, Curl_hash_str,
-                                Curl_str_key_compare, free_bundle_hash_entry);
-
-  if(!connc->hash) {
-    free(connc);
-    return NULL;
-  }
-
-  return connc;
+  return Curl_hash_init(&connc->hash, size, Curl_hash_str,
+                        Curl_str_key_compare, free_bundle_hash_entry);
 }
 
 void Curl_conncache_destroy(struct conncache *connc)
 {
-  if(connc) {
-    Curl_hash_destroy(connc->hash);
-    connc->hash = NULL;
-    free(connc);
-  }
+  if(connc)
+    Curl_hash_clean(&connc->hash);
 }
 
 struct connectbundle *Curl_conncache_find_bundle(struct connectdata *conn,
@@ -81,7 +65,7 @@ struct connectbundle *Curl_conncache_find_bundle(struct connectdata *conn,
   char *hostname = conn->bits.proxy?conn->proxy.name:conn->host.name;
 
   if(connc)
-    bundle = Curl_hash_pick(connc->hash, hostname, strlen(hostname)+1);
+    bundle = Curl_hash_pick(&connc->hash, hostname, strlen(hostname)+1);
 
   return bundle;
 }
@@ -92,7 +76,7 @@ static bool conncache_add_bundle(struct conncache *connc,
 {
   void *p;
 
-  p = Curl_hash_add(connc->hash, hostname, strlen(hostname)+1, bundle);
+  p = Curl_hash_add(&connc->hash, hostname, strlen(hostname)+1, bundle);
 
   return p?TRUE:FALSE;
 }
@@ -106,14 +90,14 @@ static void conncache_remove_bundle(struct conncache *connc,
   if(!connc)
     return;
 
-  Curl_hash_start_iterate(connc->hash, &iter);
+  Curl_hash_start_iterate(&connc->hash, &iter);
 
   he = Curl_hash_next_element(&iter);
   while(he) {
     if(he->ptr == bundle) {
       /* The bundle is destroyed by the hash destructor function,
          free_bundle_hash_entry() */
-      Curl_hash_delete(connc->hash, he->key, he->key_len);
+      Curl_hash_delete(&connc->hash, he->key, he->key_len);
       return;
     }
 
@@ -201,7 +185,7 @@ void Curl_conncache_foreach(struct conncache *connc,
   if(!connc)
     return;
 
-  Curl_hash_start_iterate(connc->hash, &iter);
+  Curl_hash_start_iterate(&connc->hash, &iter);
 
   he = Curl_hash_next_element(&iter);
   while(he) {
@@ -232,7 +216,7 @@ Curl_conncache_find_first_connection(struct conncache *connc)
   struct curl_hash_element *he;
   struct connectbundle *bundle;
 
-  Curl_hash_start_iterate(connc->hash, &iter);
+  Curl_hash_start_iterate(&connc->hash, &iter);
 
   he = Curl_hash_next_element(&iter);
   while(he) {

lib/conncache.h

@@ -24,13 +24,13 @@
  ***************************************************************************/
 
 struct conncache {
-  struct curl_hash *hash;
+  struct curl_hash hash;
   size_t num_connections;
   long next_connection_id;
   struct timeval last_cleanup;
 };
 
-struct conncache *Curl_conncache_init(int size);
+int Curl_conncache_init(struct conncache *, int size);
 
 void Curl_conncache_destroy(struct conncache *connc);
 

lib/connect.c

@@ -1214,8 +1214,8 @@ curl_socket_t Curl_getconnectinfo(struct SessionHandle *data,
     find.found = FALSE;
 
     Curl_conncache_foreach(data->multi_easy?
-                           data->multi_easy->conn_cache:
-                           data->multi->conn_cache, &find, conn_is_conn);
+                           &data->multi_easy->conn_cache:
+                           &data->multi->conn_cache, &find, conn_is_conn);
 
     if(!find.found) {
       data->state.lastconnect = NULL;

lib/multi.c

@@ -302,8 +302,7 @@ struct Curl_multi *Curl_multi_handle(int hashsize, /* socket hash */
   if(!multi->sockhash)
     goto error;
 
-  multi->conn_cache = Curl_conncache_init(chashsize);
-  if(!multi->conn_cache)
+  if(Curl_conncache_init(&multi->conn_cache, chashsize))
     goto error;
 
   multi->msglist = Curl_llist_alloc(multi_freeamsg);
@@ -320,7 +319,7 @@ struct Curl_multi *Curl_multi_handle(int hashsize, /* socket hash */
     goto error;
 
   multi->closure_handle->multi = multi;
-  multi->closure_handle->state.conn_cache = multi->conn_cache;
+  multi->closure_handle->state.conn_cache = &multi->conn_cache;
 
   multi->max_pipeline_length = 5;
 
@@ -334,8 +333,7 @@ struct Curl_multi *Curl_multi_handle(int hashsize, /* socket hash */
   multi->sockhash = NULL;
   Curl_hash_destroy(multi->hostcache);
   multi->hostcache = NULL;
-  Curl_conncache_destroy(multi->conn_cache);
-  multi->conn_cache = NULL;
+  Curl_conncache_destroy(&multi->conn_cache);
   Curl_close(multi->closure_handle);
   multi->closure_handle = NULL;
   Curl_llist_destroy(multi->msglist, NULL);
@@ -409,7 +407,7 @@ CURLMcode curl_multi_add_handle(CURLM *multi_handle,
   }
 
   /* Point to the multi's connection cache */
-  data->state.conn_cache = multi->conn_cache;
+  data->state.conn_cache = &multi->conn_cache;
 
   data->state.infilesize = data->set.filesize;
 
@@ -1832,7 +1830,7 @@ static void close_all_connections(struct Curl_multi *multi)
 {
   struct connectdata *conn;
 
-  conn = Curl_conncache_find_first_connection(multi->conn_cache);
+  conn = Curl_conncache_find_first_connection(&multi->conn_cache);
   while(conn) {
     SIGPIPE_VARIABLE(pipe_st);
     conn->data = multi->closure_handle;
@@ -1842,7 +1840,7 @@ static void close_all_connections(struct Curl_multi *multi)
     (void)Curl_disconnect(conn, FALSE);
     sigpipe_restore(&pipe_st);
 
-    conn = Curl_conncache_find_first_connection(multi->conn_cache);
+    conn = Curl_conncache_find_first_connection(&multi->conn_cache);
   }
 }
 
@@ -1873,7 +1871,7 @@ CURLMcode curl_multi_cleanup(CURLM *multi_handle)
     }
 
     Curl_hash_destroy(multi->sockhash);
-    Curl_conncache_destroy(multi->conn_cache);
+    Curl_conncache_destroy(&multi->conn_cache);
     Curl_llist_destroy(multi->msglist, NULL);
     Curl_llist_destroy(multi->pending, NULL);
 

lib/multihandle.h

@@ -22,6 +22,8 @@
  *
  ***************************************************************************/
 
+#include "conncache.h"
+
 struct Curl_message {
   /* the 'CURLMsg' is the part that is visible to the external user */
   struct CURLMsg extmsg;
@@ -99,7 +101,7 @@ struct Curl_multi {
   bool pipelining_enabled;
 
   /* Shared connection cache (bundles)*/
-  struct conncache *conn_cache;
+  struct conncache conn_cache;
 
   /* This handle will be used for closing the cached connections in
      curl_multi_cleanup() */

lib/url.c

@@ -2944,7 +2944,7 @@ find_oldest_idle_connection(struct SessionHandle *data)
 
   now = Curl_tvnow();
 
-  Curl_hash_start_iterate(bc->hash, &iter);
+  Curl_hash_start_iterate(&bc->hash, &iter);
 
   he = Curl_hash_next_element(&iter);
   while(he) {