Put keybindings in binary searchable arrays.

This patch sorts keybindings in arrays by keycode or keysym to speed up look
up using binary searches. This is a preliminary work to enable more powerful
keybindings stuff, where keybindings can be cascaded or why not, attached to
specific clients.

Interstingly enough, this patch saves 100ko of initial memory (Heap) usage here.

The underlying idea is that we should be able to define keybindings_t as
trees of keybindings_t which would then define key sequences.

The OO approach kind of make sense in fact, since you create a base
keybinding (e.g. reacting on Mod4-w) and then you will probably (with
appropriate apis) be able to populate new submaps from that point more or
less dynamically.

And if you have two keybindings on Mod4-w, then adding them will replace the
previous one. This means that you can fake per-client bindings with e.g.:

  k_default = keybindings.new({"Mod4"}, "w", something);
  k_mplayer = keybindings.new({"Mod4"}, "w", something_else);
  k_default:add()

and in your focus hook:

  if /* code for testing if it's mplayer */ then
      k_mplayer:add()
  else
      k_default:add()
  end

This would not work before, it does now.

It will take way more sense with submaps of course.

Signed-off-by: Pierre Habouzit <madcoder@debian.org>

event.c

@@ -33,6 +33,7 @@
 #include "client.h"
 #include "widget.h"
 #include "titlebar.h"
+#include "keybinding.h"
 #include "keygrabber.h"
 #include "lua.h"
 #include "systray.h"
@@ -390,8 +391,6 @@ event_handle_keypress(void *data __attribute__ ((unused)),
                       xcb_connection_t *connection __attribute__ ((unused)),
                       xcb_key_press_event_t *ev)
 {
-    xcb_keysym_t keysym;
-
     if(globalconf.keygrabber != LUA_REFNIL)
     {
         lua_rawgeti(globalconf.L, LUA_REGISTRYINDEX, globalconf.keygrabber);
@@ -409,15 +408,9 @@ event_handle_keypress(void *data __attribute__ ((unused)),
     }
     else
     {
-        keysym = xcb_key_symbols_get_keysym(globalconf.keysyms, ev->detail, 0);
-
-        for(int i = 0; i < globalconf.keys.len; i++)
-        {
-            keybinding_t *k = globalconf.keys.tab[i];
-            if(((k->keycode && ev->detail == k->keycode) || (k->keysym && keysym == k->keysym))
-               && k->fct && CLEANMASK(k->mod) == CLEANMASK(ev->state))
-                luaA_dofunction(globalconf.L, k->fct, 0);
-        }
+        keybinding_t *k = keybinding_find(&globalconf.keys, ev);
+        if (k && k->fct)
+            luaA_dofunction(globalconf.L, k->fct, 0);
     }
 
     return 0;

keybinding.c

@@ -2,6 +2,7 @@
  * keybinding.c - Key bindings configuration management
  *
  * Copyright © 2008 Julien Danjou <julien@danjou.info>
+ * Copyright © 2008 Pierre Habouzit <madcoder@debian.org>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -22,7 +23,8 @@
 /* XStringToKeysym() */
 #include <X11/Xlib.h>
 
-#include "structs.h"
+#include "keybinding.h"
+#include "event.h"
 #include "lua.h"
 #include "window.h"
 
@@ -31,27 +33,140 @@ extern awesome_t globalconf;
 DO_LUA_NEW(static, keybinding_t, keybinding, "keybinding", keybinding_ref)
 DO_LUA_GC(keybinding_t, keybinding, "keybinding", keybinding_unref)
 
+void keybinding_idx_wipe(keybinding_idx_t *idx)
+{
+    keybinding_array_wipe(&idx->by_code);
+    keybinding_array_wipe(&idx->by_sym);
+}
+
 void keybinding_delete(keybinding_t **kbp)
 {
     p_delete(kbp);
 }
 
+static int
+keybinding_ev_cmp(xcb_keysym_t keysym, xcb_keycode_t keycode,
+                  unsigned long mod, const keybinding_t *k)
+{
+    if (k->keysym) {
+        if (k->keysym != keysym)
+            return k->keysym > keysym ? 1 : -1;
+    }
+    if (k->keycode) {
+        if (k->keycode != keycode)
+            return k->keycode > keycode ? 1 : -1;
+    }
+    return k->mod == mod ? 0 : (k->mod > mod ? 1 : -1);
+}
+
+static int
+keybinding_cmp(const keybinding_t *k1, const keybinding_t *k2)
+{
+    assert ((k1->keysym && k2->keysym) || (k1->keycode && k2->keycode));
+    assert ((!k1->keysym && !k2->keysym) || (!k1->keycode && !k2->keycode));
+
+    if (k1->keysym != k2->keysym)
+        return k2->keysym > k1->keysym ? 1 : -1;
+    if (k1->keycode != k2->keycode)
+        return k2->keycode > k1->keycode ? 1 : -1;
+    return k1->mod == k2->mod ? 0 : (k2->mod > k1->mod ? 1 : -1);
+}
+
+void
+keybinding_register_root(keybinding_t *k)
+{
+    keybinding_idx_t *idx = &globalconf.keys;
+    keybinding_array_t *arr = k->keysym ? &idx->by_sym : &idx->by_code;
+    int l = 0, r = arr->len;
+
+    keybinding_ref(&k);
+
+    while (l < r) {
+        int i = (r + l) / 2;
+        switch (keybinding_cmp(k, arr->tab[i])) {
+          case -1: /* k < arr->tab[i] */
+            r = i;
+            break;
+          case 0: /* k == arr->tab[i] */
+            keybinding_unref(&arr->tab[i]);
+            arr->tab[i] = k;
+            return;
+          case 1: /* k > arr->tab[i] */
+            l = i + 1;
+            break;
+        }
+    }
+
+    keybinding_array_splice(arr, r, 0, &k, 1);
+    window_root_grabkey(k);
+}
+
+void
+keybinding_unregister_root(keybinding_t **k)
+{
+    keybinding_idx_t *idx = &globalconf.keys;
+    keybinding_array_t *arr = (*k)->keysym ? &idx->by_sym : &idx->by_code;
+    int l = 0, r = arr->len;
+
+    while (l < r) {
+        int i = (r + l) / 2;
+        switch (keybinding_cmp(*k, arr->tab[i])) {
+          case -1: /* k < arr->tab[i] */
+            r = i;
+            break;
+          case 0: /* k == arr->tab[i] */
+            keybinding_array_take(arr, i);
+            window_root_ungrabkey(*k);
+            keybinding_unref(k);
+            return;
+          case 1: /* k > arr->tab[i] */
+            l = i + 1;
+            break;
+        }
+    }
+}
+
+keybinding_t *
+keybinding_find(const keybinding_idx_t *idx, const xcb_key_press_event_t *ev)
+{
+    const keybinding_array_t *arr = &idx->by_sym;
+    int l, r, mod = CLEANMASK(ev->state);
+    xcb_keysym_t keysym;
+
+    keysym = xcb_key_symbols_get_keysym(globalconf.keysyms, ev->detail, 0);
+
+  again:
+    l = 0;
+    r = arr->len;
+    while (l < r) {
+        int i = (r + l) / 2;
+        switch (keybinding_ev_cmp(keysym, ev->detail, mod, arr->tab[i])) {
+          case -1: /* ev < arr->tab[i] */
+            r = i;
+            break;
+          case 0: /* ev == arr->tab[i] */
+            return arr->tab[i];
+          case 1: /* ev > arr->tab[i] */
+            l = i + 1;
+            break;
+        }
+    }
+    if (arr != &idx->by_code) {
+        arr = &idx->by_code;
+        goto again;
+    }
+    return NULL;
+}
+
 static void
 __luaA_keystore(keybinding_t *key, const char *str)
 {
-    xcb_keycode_t kc;
-    int ikc;
-
     if(!a_strlen(str))
         return;
-    else if(a_strncmp(str, "#", 1))
+    else if(*str != '#')
         key->keysym = XStringToKeysym(str);
     else
-    {
-        ikc = atoi(str + 1);
-        memcpy(&kc, &ikc, sizeof(KeyCode));
-        key->keycode = kc;
-    }
+        key->keycode = atoi(str + 1);
 }
 
 /** Define a global key binding. This key binding will always be available.
@@ -103,14 +218,7 @@ luaA_keybinding_add(lua_State *L)
 {
     keybinding_t **k = luaA_checkudata(L, 1, "keybinding");
 
-    /* Check that the keybinding has not been already added. */
-    for(int i = 0; i < globalconf.keys.len; i++)
-        if(globalconf.keys.tab[i] == *k)
-            luaL_error(L, "keybinding already added");
-
-    keybinding_array_append(&globalconf.keys, keybinding_ref(k));
-    window_root_grabkey(*k);
-
+    keybinding_register_root(*k);
     return 0;
 }
 
@@ -124,15 +232,7 @@ static int
 luaA_keybinding_remove(lua_State *L)
 {
     keybinding_t **k = luaA_checkudata(L, 1, "keybinding");
-
-    for(int i = 0; i < globalconf.keys.len; i++)
-        if(globalconf.keys.tab[i] == *k)
-        {
-            keybinding_array_take(&globalconf.keys, i);
-            window_root_ungrabkey(*k);
-            keybinding_unref(k);
-        }
-
+    keybinding_unregister_root(k);
     return 0;
 }
 

keybinding.h

@@ -0,0 +1,38 @@
+/*
+ * keybinding.h - Keybinding helpers
+ *
+ * Copyright © 2008 Pierre Habouzit <madcoder@debian.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#ifndef AWESOME_KEYBINDING_H
+#define AWESOME_KEYBINDING_H
+
+#include "structs.h"
+
+void keybinding_delete(keybinding_t **);
+DO_RCNT(keybinding_t, keybinding, keybinding_delete)
+ARRAY_FUNCS(keybinding_t *, keybinding, keybinding_unref)
+
+void keybinding_idx_wipe(keybinding_idx_t *);
+
+void keybinding_register_root(keybinding_t *);
+void keybinding_unregiste_rootr(keybinding_t **);
+keybinding_t *keybinding_find(const keybinding_idx_t *,
+                              const xcb_key_press_event_t *);
+
+#endif

structs.h

@@ -207,6 +207,12 @@ DO_RCNT(titlebar_t, titlebar, titlebar_delete)
 
 /** Keys bindings */
 ARRAY_TYPE(struct keybinding_t *, keybinding);
+
+typedef struct keybinding_idx_t {
+    keybinding_array_t by_code;
+    keybinding_array_t by_sym;
+} keybinding_idx_t;
+
 struct keybinding_t
 {
     /** Ref count */
@@ -221,10 +227,6 @@ struct keybinding_t
     luaA_function fct;
 };
 
-void keybinding_delete(keybinding_t **);
-DO_RCNT(keybinding_t, keybinding, keybinding_delete)
-ARRAY_FUNCS(keybinding_t *, keybinding, keybinding_unref)
-
 /** Status bar */
 struct statusbar_t
 {
@@ -399,7 +401,7 @@ struct awesome_t
     /** Screens info */
     screens_info_t *screens_info;
     /** Keys bindings list */
-    keybinding_array_t keys;
+    keybinding_idx_t keys;
     /** Mouse bindings list */
     struct
     {