Changeset 9e83b15 for lib/misc.c

Timestamp:

2018-07-03T05:58:47Z (6 years ago)

Author:

dequis <dx@…>

Branches:

master

Children:

c17d0af

Parents:

49ab3cb

git-author:

dequis <dx@…> (03-07-18 05:27:59)

git-committer:

dequis <dx@…> (03-07-18 05:58:47)

Message:

Add a hash table to speed up bee_user_by_handle()

This maintains a hash table next to the linked list, which results in
negligible additional memory usage (~300kb for 10k users) but allows
instant lookups.

This was a big problem with discord, which has huge user lists and joins
everyone to every channel. In my test, the GUILD_SYNC event for 10k-50k
user lists is now approximately 5 times faster.

This hash table based code is only used if handle_cmp is either
exact or case-insensitive string comparison (g_ascii_strcasecmp or
strcmp/g_strcmp0).

The old function that goes through the bee->users linked list is now
called bee_user_by_handle_slow() and used for protocols with unusual
handle_cmp functions - skimming through the code, just oscar.
May revisit this if it happens to more meaningful protocols.

The case-insensitive hashtable functions are copied from irssi, which is
also GPLv2. I renamed them from g_ to b_ (g_istr_equal to b_istr_equal)

File:

• lib/misc.c (modified) (1 diff)

lib/misc.c

@@ -774 +774 @@
         }
 }
+
+/* copied from irssi's misc.c, by timo sirainen */
+int b_istr_equal(gconstpointer v, gconstpointer v2)
+{
+        return g_ascii_strcasecmp((const char *) v, (const char *) v2) == 0;
+}
+
+/* copied from irssi's misc.c, by lemonboy */
+guint b_istr_hash(gconstpointer v)
+{
+        const signed char *p;
+        guint32 h = 5381;
+
+        for (p = v; *p != '\0'; p++) {
+                h = (h << 5) + h + g_ascii_toupper(*p);
+        }
+
+        return h;
+}