From 026955e37517d07679ea8044d939400d6e9beaaf Mon Sep 17 00:00:00 2001
From: glass <glass@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Thu, 10 Oct 2013 12:06:01 +0000
Subject: [PATCH] * st.c (st_keys): define st_keys() for performance
 improvement of   Hash#keys and Array#uniq.

* st.h: ditto.

* hash.c (rb_hash_keys): use st_keys().

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43238 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog         |  9 +++++++++
 hash.c            | 15 +++------------
 include/ruby/st.h |  1 +
 st.c              | 31 +++++++++++++++++++++++++++++++
 4 files changed, 44 insertions(+), 12 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 6268bf2fa3..d364242095 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+Thu Oct 10 21:00:38 2013  Masaki Matsushita  <glass.saga@gmail.com>
+
+	* st.c (st_keys): define st_keys() for performance improvement of
+	  Hash#keys and Array#uniq.
+
+	* st.h: ditto.
+
+	* hash.c (rb_hash_keys): use st_keys().
+
 Thu Oct 10 17:25:28 2013  Koichi Sasada  <ko1@atdot.net>
 
 	* vm.c (vm_exec): support :b_return event for "lambda{return}.call".
diff --git a/hash.c b/hash.c
index 83d179964f..2cedeefb10 100644
--- a/hash.c
+++ b/hash.c
@@ -1663,13 +1663,6 @@ rb_hash_to_h(VALUE hash)
     return hash;
 }
 
-static int
-keys_i(VALUE key, VALUE value, VALUE ary)
-{
-    rb_ary_push(ary, key);
-    return ST_CONTINUE;
-}
-
 /*
  *  call-seq:
  *     hsh.keys    -> array
@@ -1685,12 +1678,10 @@ keys_i(VALUE key, VALUE value, VALUE ary)
 VALUE
 rb_hash_keys(VALUE hash)
 {
-    VALUE ary;
+    st_table *table = RHASH(hash)->ntbl;
 
-    ary = rb_ary_new_capa(RHASH_SIZE(hash));
-    rb_hash_foreach(hash, keys_i, ary);
-
-    return ary;
+    if (!table) return rb_ary_new();
+    return st_keys(table);
 }
 
 static int
diff --git a/include/ruby/st.h b/include/ruby/st.h
index e71301b519..5968a1fc22 100644
--- a/include/ruby/st.h
+++ b/include/ruby/st.h
@@ -112,6 +112,7 @@ int st_update(st_table *table, st_data_t key, st_update_callback_func *func, st_
 int st_foreach(st_table *, int (*)(ANYARGS), st_data_t);
 int st_foreach_check(st_table *, int (*)(ANYARGS), st_data_t, st_data_t);
 int st_reverse_foreach(st_table *, int (*)(ANYARGS), st_data_t);
+VALUE st_keys(st_table *table);
 void st_add_direct(st_table *, st_data_t, st_data_t);
 void st_free_table(st_table *);
 void st_cleanup_safe(st_table *, st_data_t);
diff --git a/st.c b/st.c
index 6e3df628a7..43e2d71d24 100644
--- a/st.c
+++ b/st.c
@@ -1091,6 +1091,37 @@ st_foreach(st_table *table, int (*func)(ANYARGS), st_data_t arg)
     return 0;
 }
 
+VALUE
+st_keys(st_table *table)
+{
+    st_table_entry *ptr = NULL;
+    st_data_t key, never = (st_data_t)Qundef;
+    VALUE keys = rb_ary_new_capa(table->num_entries);
+
+    if (table->entries_packed) {
+	st_index_t i;
+
+	for (i = 0; i < table->real_entries; i++) {
+	    key = PKEY(table, i);
+	    if (key == never) continue;
+	    rb_ary_push(keys, (VALUE)key);
+	}
+    }
+    else {
+	ptr = table->head;
+    }
+
+    if (ptr != 0) {
+	do {
+	    key = ptr->key;
+	    if (key != never) rb_ary_push(keys, (VALUE)key);
+	    ptr = ptr->fore;
+	} while (ptr && table->head);
+    }
+
+    return keys;
+}
+
 #if 0  /* unused right now */
 int
 st_reverse_foreach(st_table *table, int (*func)(ANYARGS), st_data_t arg)