From ab881e31dca0b724145aceac7f65d485dab65fa6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lourens=20Naud=C3=A9?= <lourens@methodmissing.com>
Date: Fri, 15 May 2015 23:20:48 -0400
Subject: [PATCH] Implement Symbol.count as a much cheaper alternative to
 Symbol.all_symbols.size

---
 ChangeLog                | 16 ++++++++++++++++
 include/ruby/intern.h    |  4 +++-
 string.c                 |  1 +
 symbol.c                 | 19 +++++++++++++++++++
 test/ruby/test_parse.rb  |  6 ------
 test/ruby/test_symbol.rb | 12 ++++++++++++
 6 files changed, 51 insertions(+), 7 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 19c5c82..b2fd3ae 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,19 @@
+Fri May 15 23:32:31 2015  Lourens Naudé  <lourens@methodmissing.com>
+
+	* symbol.c (rb_sym_count): Implement `rb_sym_count` to expose the number of
+	  Symbol table entries as a numeric value without having to rely on the very
+	  slow `rb_sym_all_symbols` API.
+
+	* include/ruby/intern.h (rb_sym_count): Expose `rb_sym_count` API. Move
+	  `rb_sym_all_symbols` to a symbol.c specific section (does not live in parse.y
+	  anymore)
+
+	* string.c (Init_string): Implement Symbol.count
+
+	* test/ruby/test_symbol.rb: Test for API addition.
+
+	* test/ruby/test_parse.rb: Moved `test_all_symbols` to test/ruby/test_symbol.rb
+
 Fri May 15 18:28:20 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* array.c (rb_ary_assoc, rb_ary_rassoc): [DOC] the result when key
diff --git a/include/ruby/intern.h b/include/ruby/intern.h
index 127de00..2ecc982 100644
--- a/include/ruby/intern.h
+++ b/include/ruby/intern.h
@@ -632,7 +632,6 @@ VALUE rb_backref_get(void);
 void rb_backref_set(VALUE);
 VALUE rb_lastline_get(void);
 void rb_lastline_set(VALUE);
-VALUE rb_sym_all_symbols(void);
 /* process.c */
 void rb_last_status_set(int status, rb_pid_t pid);
 VALUE rb_last_status_get(void);
@@ -786,6 +785,9 @@ long rb_str_offset(VALUE, long);
 size_t rb_str_capacity(VALUE);
 VALUE rb_str_ellipsize(VALUE, long);
 VALUE rb_str_scrub(VALUE, VALUE);
+/* symbol.c */
+VALUE rb_sym_all_symbols(void);
+VALUE rb_sym_count(void);
 
 #if defined(__GNUC__) && !defined(__PCC__)
 #define rb_str_new(str, len) __extension__ (	\
diff --git a/string.c b/string.c
index 943c18c..2a0e3db 100644
--- a/string.c
+++ b/string.c
@@ -9234,6 +9234,7 @@ Init_String(void)
     rb_undef_alloc_func(rb_cSymbol);
     rb_undef_method(CLASS_OF(rb_cSymbol), "new");
     rb_define_singleton_method(rb_cSymbol, "all_symbols", rb_sym_all_symbols, 0); /* in symbol.c */
+    rb_define_singleton_method(rb_cSymbol, "count", rb_sym_count, 0); /* in symbol.c */
 
     rb_define_method(rb_cSymbol, "==", sym_equal, 1);
     rb_define_method(rb_cSymbol, "===", sym_equal, 1);
diff --git a/symbol.c b/symbol.c
index 63064d3..07de8bd 100644
--- a/symbol.c
+++ b/symbol.c
@@ -847,6 +847,25 @@ rb_sym_all_symbols(void)
     return ary;
 }
 
+/*
+ *  call-seq:
+ *     Symbol.count    => integer
+ *
+ *  Returns an integer value representing the size of Ruby's symbol table.
+ *
+ *     Symbol.count    #=> 903
+ */
+
+VALUE
+rb_sym_count(void)
+{
+#if SIZEOF_LONG == SIZEOF_VOIDP
+    return ULONG2NUM(global_symbols.str_sym->num_entries);
+#elif SIZEOF_LONG_LONG == SIZEOF_VOIDP
+    return ULL2NUM(global_symbols.str_sym->num_entries);
+#endif
+}
+
 int
 rb_is_const_id(ID id)
 {
diff --git a/test/ruby/test_parse.rb b/test/ruby/test_parse.rb
index 216cdc0..9f91125 100644
--- a/test/ruby/test_parse.rb
+++ b/test/ruby/test_parse.rb
@@ -846,12 +846,6 @@ def test_intern
     assert_equal(':"foo=="', "foo==".intern.inspect)
   end
 
-  def test_all_symbols
-    x = Symbol.all_symbols
-    assert_kind_of(Array, x)
-    assert_empty(x.reject {|s| s.is_a?(Symbol) })
-  end
-
   def test_is_class_id
     c = Class.new
     assert_raise(NameError) do
diff --git a/test/ruby/test_symbol.rb b/test/ruby/test_symbol.rb
index 0a055db..96f7c0c 100644
--- a/test/ruby/test_symbol.rb
+++ b/test/ruby/test_symbol.rb
@@ -12,6 +12,18 @@ def assert_eval_inspected(sym, valid = true)
     assert_nothing_raised(SyntaxError) {assert_equal(sym, eval(n))}
   end
 
+  def test_all_symbols
+    x = Symbol.all_symbols
+    assert_kind_of(Array, x)
+    assert_empty(x.reject {|s| s.is_a?(Symbol) })
+  end
+
+  def test_count
+    x = Symbol.count
+    assert_kind_of(Fixnum, x)
+    assert_equal x, Symbol.all_symbols.size
+  end
+
   def test_inspect_invalid
     # 2) Symbol#inspect sometimes returns invalid symbol representations:
     assert_eval_inspected(:"!")