Add a configure option to disable hash-table entry caches

2 files changed, 31 insertions, 3 deletions

diff --git a/configure.ac b/configure.ac
index 3da0bde1..ba6610d5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1649,6 +1649,15 @@ if test "x$enable_link_caches" = xyes; then
     [Define to reduce memory use at a performance cost])
 fi
 
+AC_ARG_ENABLE([hash-entry-caches],
+  [AS_HELP_STRING([--disable-hash-entry-caches],
+    [disable hash-table entry caches, decreasing performance and memory use])],
+  [], [enable_hash_entry_caches=yes])
+if test "x$enable_hash_entry_caches" = xyes; then
+  AC_DEFINE([DBUS_ENABLE_HASH_ENTRY_CACHES], [1],
+    [Define to improve performance at a small memory cost])
+fi
+
 AC_CONFIG_FILES([
 Doxyfile
 dbus/versioninfo.rc
diff --git a/dbus/dbus-hash.c b/dbus/dbus-hash.c
index 67ef4ced..4776b6d6 100644
--- a/dbus/dbus-hash.c
+++ b/dbus/dbus-hash.c
@@ -203,7 +203,9 @@ struct DBusHashTable {
   DBusFreeFunction free_key_function;   /**< Function to free keys */
   DBusFreeFunction free_value_function; /**< Function to free values */
 
+#ifdef DBUS_ENABLE_HASH_ENTRY_CACHES
   DBusMemPool *entry_pool;              /**< Memory pool for hash entries */
+#endif
 };
 
 /** 
@@ -295,21 +297,25 @@ _dbus_hash_table_new (DBusHashType     type,
                       DBusFreeFunction value_free_function)
 {
   DBusHashTable *table;
+#ifdef DBUS_ENABLE_HASH_ENTRY_CACHES
   DBusMemPool *entry_pool;
+#endif
   
   table = dbus_new0 (DBusHashTable, 1);
   if (table == NULL)
     return NULL;
 
+#ifdef DBUS_ENABLE_HASH_ENTRY_CACHES
   entry_pool = _dbus_mem_pool_new (sizeof (DBusHashEntry), TRUE);
   if (entry_pool == NULL)
     {
       dbus_free (table);
       return NULL;
     }
+  table->entry_pool = entry_pool;
+#endif
   
   table->refcount = 1;
-  table->entry_pool = entry_pool;
   
   _dbus_assert (DBUS_SMALL_HASH_TABLE == _DBUS_N_ELEMENTS (table->static_buckets));
   
@@ -378,7 +384,7 @@ _dbus_hash_table_unref (DBusHashTable *table)
 
   if (table->refcount == 0)
     {
-#if 0
+#ifndef DBUS_ENABLE_HASH_ENTRY_CACHES
       DBusHashEntry *entry;
       DBusHashEntry *next;
       int i;
@@ -444,8 +450,12 @@ alloc_entry (DBusHashTable *table)
 {
   DBusHashEntry *entry;
 
+#ifdef DBUS_ENABLE_HASH_ENTRY_CACHES
   entry = _dbus_mem_pool_alloc (table->entry_pool);
-  
+#else
+  entry = dbus_malloc0 (sizeof (DBusHashEntry));
+#endif
+
   return entry;
 }
 
@@ -464,7 +474,12 @@ free_entry (DBusHashTable  *table,
             DBusHashEntry  *entry)
 {
   free_entry_data (table, entry);
+
+#ifdef DBUS_ENABLE_HASH_ENTRY_CACHES
   _dbus_mem_pool_dealloc (table->entry_pool, entry);
+#else
+  dbus_free (entry);
+#endif
 }
 
 static void
@@ -1651,7 +1666,11 @@ _dbus_hash_table_free_preallocated_entry (DBusHashTable        *table,
   entry = (DBusHashEntry*) preallocated;
   
   /* Don't use free_entry(), since this entry has no key/data */
+#ifdef DBUS_ENABLE_HASH_ENTRY_CACHES
   _dbus_mem_pool_dealloc (table->entry_pool, entry);
+#else
+  dbus_free (entry);
+#endif
 }
 
 /**