Bug #14908
Updated by chopraanmol1 (Anmol Chopra) over 5 years ago
Benchmark result on trunk:
~~~
user system total real
Lazy: 0.120000 0.000000 0.120000 ( 0.119958)
Normal: 0.056000 0.004000 0.060000 ( 0.062848)
2.142857 0.000000 NaN ( 1.908698)
++++++++++++++++++++++++++++++++++++++++++++++++++
Lazy:
Total allocated: 122240 bytes (3033 objects)
Total retained: 0 bytes (0 objects)
allocated memory by class
--------------------------------------------------
120480 Array
880 Proc
384 Enumerator::Lazy
264 Object
168 Enumerator::Generator
64 Enumerator::Yielder
allocated objects by class
--------------------------------------------------
3012 Array
11 Proc
3 Enumerator::Generator
3 Enumerator::Lazy
3 Object
1 Enumerator::Yielder
++++++++++++++++++++++++++++++++++++++++++++++++++
++++++++++++++++++++++++++++++++++++++++++++++++++
Normal:
Total allocated: 72120 bytes (3 objects)
Total retained: 0 bytes (0 objects)
allocated memory by class
--------------------------------------------------
72120 Array
allocated objects by class
--------------------------------------------------
3 Array
++++++++++++++++++++++++++++++++++++++++++++++++++
~~~
As you may observe an extra array is created for every final element. Enumerator::Yielder#yield method has arity of -1 which wrap every elements in array. The same goes for Enumerator::Yielder#<< method, I'm proposing to change arity for Enumerator::Yielder#<< to 1 from -1 and use it internally for the lazy enum. -1. It will also make << method definition consistent with other classes(Array, String & etc).
I've applied the following set of changes:
**https://github.com/ruby/ruby/pull/1912** changes to trunk(Pull Request for the same: https://github.com/ruby/ruby/pull/1912):
~~~
diff --git a/enumerator.c b/enumerator.c
index 050a9ce58f..c21d6f36f1 100644
--- a/enumerator.c
+++ b/enumerator.c
@@ -103,7 +103,7 @@
*/
VALUE rb_cEnumerator;
static VALUE rb_cLazy;
-static ID id_rewind, id_new, id_yield, id_to_enum;
+static ID id_rewind, id_new, id_yield, id_yield_push, id_to_enum;
static ID id_next, id_result, id_lazy, id_receiver, id_arguments, id_memo, id_method, id_force;
static VALUE sym_each, sym_cycle;
@@ -1265,9 +1265,14 @@ yielder_yield(VALUE obj, VALUE args)
/* :nodoc: */
static VALUE
-yielder_yield_push(VALUE obj, VALUE args)
+yielder_yield_push(VALUE obj, VALUE arg)
{
- yielder_yield(obj, args);
+ struct yielder *ptr = yielder_ptr(obj);
+
+ rb_proc_call_with_block(ptr->proc, 1, &arg, Qnil);
+
return obj;
}
@@ -1510,7 +1515,7 @@ lazy_init_yielder(VALUE val, VALUE m, int argc, VALUE *argv)
}
if (cont) {
- rb_funcall2(yielder, id_yield, 1, &(result->memo_value));
+ rb_funcall2(yielder, id_yield_push, 1, &(result->memo_value));
}
if (LAZY_MEMO_BREAK_P(result)) {
rb_iter_break();
@@ -2448,7 +2453,7 @@ InitVM_Enumerator(void)
rb_define_alloc_func(rb_cYielder, yielder_allocate);
rb_define_method(rb_cYielder, "initialize", yielder_initialize, 0);
rb_define_method(rb_cYielder, "yield", yielder_yield, -2);
- rb_define_method(rb_cYielder, "<<", yielder_yield_push, -2);
+ rb_define_method(rb_cYielder, "<<", yielder_yield_push, 1);
rb_provide("enumerator.so"); /* for backward compatibility */
}
@@ -2459,6 +2464,7 @@ Init_Enumerator(void)
{
id_rewind = rb_intern("rewind");
id_yield = rb_intern("yield");
+ id_yield_push = rb_intern("<<");
id_new = rb_intern("new");
id_next = rb_intern("next");
id_result = rb_intern("result");
~~~
which result in the following:
~~~
user system total real
Lazy: 0.108000 0.000000 0.108000 ( 0.108484)
Normal: 0.052000 0.008000 0.060000 ( 0.062528)
2.076923 0.000000 NaN ( 1.734961)
++++++++++++++++++++++++++++++++++++++++++++++++++
Lazy:
Total allocated: 2240 bytes (33 objects)
Total retained: 0 bytes (0 objects)
allocated memory by class
--------------------------------------------------
880 Proc
480 Array
384 Enumerator::Lazy
264 Object
168 Enumerator::Generator
64 Enumerator::Yielder
allocated objects by class
--------------------------------------------------
12 Array
11 Proc
3 Enumerator::Generator
3 Enumerator::Lazy
3 Object
1 Enumerator::Yielder
++++++++++++++++++++++++++++++++++++++++++++++++++
++++++++++++++++++++++++++++++++++++++++++++++++++
Normal:
Total allocated: 72120 bytes (3 objects)
Total retained: 0 bytes (0 objects)
allocated memory by class
--------------------------------------------------
72120 Array
allocated objects by class
--------------------------------------------------
3 Array
++++++++++++++++++++++++++++++++++++++++++++++++++
~~~
This changes reduces the memory utilization and also by a tiny fraction improves performance for the lazy enumerator