make old_race a little bit less awful.

src/kernel/config.c

@@ -137,16 +137,6 @@ int NMRTimeout(void)
     return config_get_int("nmr.timeout", 0);
 }
 
-race_t old_race(const struct race * rc)
-{
-    race_t i;
-    // TODO: this sucks so bad!
-    for (i = 0; i != MAXRACES; ++i) {
-        if (get_race(i) == rc)  return i;
-    }
-    return NORACE;
-}
-
 helpmode helpmodes[] = {
     { "all", HELP_ALL }
     ,

src/kernel/race.c

@@ -86,6 +86,50 @@ const struct race *get_race(race_t rt) {
     return rc_find(name);
 }
 
+typedef struct xref {
+    race_t id;
+    const race *rc;
+} rc_xref;
+
+int cmp_xref(const void *a, const void *b)
+{
+    const rc_xref *l = (const rc_xref *)a;
+    const rc_xref *r = (const rc_xref *)b;
+    if (l->rc<r->rc) return -1;
+    if (l->rc>r->rc) return 1;
+    return 0;
+}
+
+race_t old_race(const struct race * rc)
+{
+    static int cache;
+    static rc_xref *xrefs;
+    int i, l, r;
+    
+    if (rc_changed(&cache)) {
+        if (!xrefs) {
+            xrefs = malloc(sizeof(rc_xref) * MAXRACES);
+        }
+        for (i = 0; i != MAXRACES; ++i) {
+            xrefs[i].rc = get_race(i);
+            xrefs[i].id = (race_t)i;
+        }
+        qsort(xrefs, MAXRACES, sizeof(rc_xref), cmp_xref);
+    }
+    l=0; r=MAXRACES-1;
+    while (l<=r) {
+        int m = (l+r)/2;
+        if (rc<xrefs[m].rc) {
+            r = m-1;
+        } else if (rc>xrefs[m].rc) {
+            l = m+1;
+        } else {
+            return (race_t)xrefs[m].id;
+        }
+    }
+    return NORACE;
+}
+
 race_list *get_familiarraces(void)
 {
     static int init = 0;

src/kernel/race.test.c

@@ -66,10 +66,26 @@ static void test_race_get(CuTest *tc) {
     test_cleanup();
 }
 
+static void test_old_race(CuTest *tc)
+{
+    race * rc1, *rc2;
+    test_setup();
+    test_create_race("dwarf");
+    rc1 = test_create_race("elf");
+    rc2 = test_create_race("onkel");
+    CuAssertIntEquals(tc, RC_ELF, old_race(rc1));
+    CuAssertIntEquals(tc, NORACE, old_race(rc2));
+    rc2 = test_create_race("human");
+    CuAssertIntEquals(tc, RC_ELF, old_race(rc1));
+    CuAssertIntEquals(tc, RC_HUMAN, old_race(rc2));
+    test_cleanup();
+}
+
 CuSuite *get_race_suite(void)
 {
     CuSuite *suite = CuSuiteNew();
     SUITE_ADD_TEST(suite, test_race_get);
+    SUITE_ADD_TEST(suite, test_old_race);
     SUITE_ADD_TEST(suite, test_rc_name);
     SUITE_ADD_TEST(suite, test_rc_defaults);
     SUITE_ADD_TEST(suite, test_rc_find);