Clean Array by using a Reflector (simple mirror)

Array left it's guts exposed to deal with the way that data has to be
exposed in ruby. To clean things up, I've introduce a Reflector class
which is a simple mirror. This can easily access the internal data of an
object. Additionally, rather than using instance_variable_[get|set] the
JIT can make access quite fast because it doesn't have to deal with any
edgecases.

kernel/bootstrap/array.rb

@@ -1,8 +1,7 @@
 # -*- encoding: us-ascii -*-
 
 class Array
-  attr_accessor :tuple
-  attr_accessor :start
+  attr_reader :tuple
 
   attr_reader_specific :total, :size
   alias_method :length, :size

kernel/bootstrap/array18.rb

@@ -5,21 +5,19 @@ class Array
   # each element in self to the supplied block.
   def map
     return dup unless block_given?
-    out = Array.new size
+    tup = Rubinius::Tuple.new size
 
     i = @start
     total = i + @total
     tuple = @tuple
 
-    out_tuple = out.tuple
-
     j = 0
     while i < total
-      out_tuple[j] = yield tuple.at(i)
+      tup[j] = yield tuple.at(i)
       i += 1
       j += 1
     end
 
-    out
+    Array.wrap tup, size
   end
 end

kernel/bootstrap/array19.rb

@@ -5,21 +5,19 @@ class Array
   # each element in self to the supplied block.
   def map
     return to_enum :map unless block_given?
-    out = Array.new size
+    out = Rubinius::Tuple.new size
 
     i = @start
     total = i + @total
     tuple = @tuple
 
-    out_tuple = out.tuple
-
     j = 0
     while i < total
-      out_tuple[j] = yield tuple.at(i)
+      out[j] = yield tuple.at(i)
       i += 1
       j += 1
     end
 
-    out
+    Array.wrap out, size
   end
 end

kernel/bootstrap/load_order18.txt

@@ -29,6 +29,7 @@ process.rbc
 regexp.rbc
 rubinius.rbc
 constant_scope.rbc
+reflector.rbc
 string.rbc
 symbol.rbc
 thread.rbc

kernel/bootstrap/load_order19.txt

@@ -32,6 +32,7 @@ regexp.rbc
 regexp19.rbc
 rubinius.rbc
 constant_scope.rbc
+reflector.rbc
 string.rbc
 string19.rbc
 symbol.rbc

kernel/bootstrap/reflector.rb

@@ -0,0 +1,19 @@
+module Rubinius
+  class Reflector
+
+    def self.new(target)
+      Rubinius.primitive :reflector_create
+      raise PrimitiveFailure, "Reflector.new failed"
+    end
+
+    def get(ivar)
+      Rubinius.primitive :reflector_get
+      raise PrimitiveFailure, "Reflector#get failed"
+    end
+
+    def set(ivar, name)
+      Rubinius.primitive :reflector_set
+      raise TypeError, "'#{name}' is not a ivar name"
+    end
+  end
+end

kernel/common/array.rb

@@ -34,8 +34,10 @@ def initialize(size_or_array=undefined, obj=undefined)
       if size_or_array.respond_to? :to_ary
         ary = Rubinius::Type.coerce_to size_or_array, Array, :to_ary
 
-        @tuple = ary.tuple.dup
-        @start = ary.start
+        ref = Rubinius::Reflector.new ary
+
+        @tuple = ref.get(:@tuple).dup
+        @start = ref.get :@start
         @total = ary.size
 
         return self
@@ -70,9 +72,11 @@ def replace(other)
 
     other = Rubinius::Type.coerce_to other, Array, :to_ary
 
-    @tuple = other.tuple.dup
+    ref = Rubinius::Reflector.new other
+
+    @tuple = ref.get(:@tuple).dup
+    @start = ref.get(:@start)
     @total = other.size
-    @start = other.start
 
     Rubinius::Type.infect(self, other)
     self
@@ -249,11 +253,13 @@ def ==(other)
     return false unless size == other.size
 
     Thread.detect_recursion self, other do
+      ref = Rubinius::Reflector.new other
+
       md = @tuple
-      od = other.tuple
+      od = ref.get :@tuple
 
       i = @start
-      j = other.start
+      j = ref.get :@start
 
       total = i + @total
 
@@ -1077,9 +1083,11 @@ def recursively_flatten(array, out, max_levels = -1)
 
     max_levels -= 1
     recursion = Thread.detect_recursion(array) do
-      i = array.start
+      ref = Rubinius::Reflector.new array
+
+      i = ref.get :@start
       total = i + array.size
-      tuple = array.tuple
+      tuple = ref.get :@tuple
 
       while i < total
         o = tuple.at i

kernel/common/array18.rb

@@ -122,7 +122,8 @@ def set_index(index, ent, fin=undefined)
         when 0
           # nothing
         else
-          new_tuple.copy_from(replacement.tuple, replacement.start,
+          ref = Rubinius::Reflector.new replacement
+          new_tuple.copy_from(ref.get(:@tuple), ref.get(:@start),
                               replace_count, index)
         end
 
@@ -150,7 +151,8 @@ def set_index(index, ent, fin=undefined)
         when 0
           # nothing
         else
-          @tuple.copy_from(replacement.tuple, replacement.start,
+          ref = Rubinius::Reflector.new replacement
+          @tuple.copy_from(ref.get(:@tuple), ref.get(:@start),
                               replace_count, @start + index)
         end
 
@@ -466,8 +468,11 @@ def uniq!
     Rubinius.check_frozen
 
     array = im.to_array
-    @tuple = array.tuple
-    @start = array.start
+
+    ref = Rubinius::Reflector.new array
+
+    @tuple = ref.get :@tuple
+    @start = ref.get :@start
     @total = array.size
 
     self
@@ -496,19 +501,27 @@ def unshift(*values)
 
     Rubinius.check_frozen
 
-    if @start > values.size
+    sz = values.size
+
+    if @start > sz
       # fit the new values in between 0 and @start if possible
-      @start -= values.size
-      @tuple.copy_from(values.tuple, 0, values.size, @start)
+      @start -= sz
+      if sz == 1
+        @tuple.put @start, values.at(0)
+      else
+        ref = Rubinius::Reflector.new values
+        @tuple.copy_from(ref.get(:@tuple), 0, sz, @start)
+      end
     else
-      new_tuple = Rubinius::Tuple.new @total + values.size
-      new_tuple.copy_from values.tuple, 0, values.size, 0
-      new_tuple.copy_from @tuple, @start, @total, values.size
+      ref = Rubinius::Reflector.new values
+      new_tuple = Rubinius::Tuple.new @total + sz
+      new_tuple.copy_from ref.get(:@tuple), 0, sz, 0
+      new_tuple.copy_from @tuple, @start, @total, sz
       @start = 0
       @tuple = new_tuple
     end
 
-    @total += values.size
+    @total += sz
     self
   end
 end

kernel/common/array19.rb

@@ -97,7 +97,9 @@ def set_index(index, ent, fin=undefined)
         when 0
           # nothing
         else
-          new_tuple.copy_from(replacement.tuple, replacement.start,
+          ref = Rubinius::Reflector.new replacement
+
+          new_tuple.copy_from(ref.get(:@tuple), ref.get(:@start),
                               replace_count, index)
         end
 
@@ -125,7 +127,9 @@ def set_index(index, ent, fin=undefined)
         when 0
           # nothing
         else
-          @tuple.copy_from(replacement.tuple, replacement.start,
+          ref = Rubinius::Reflector.new(replacement)
+
+          @tuple.copy_from(ref.get(:@tuple), ref.get(:@start),
                               replace_count, @start + index)
         end
 
@@ -461,11 +465,14 @@ def sample(*args)
     return at(random_generator.rand(size)) unless n
 
     n = size if n > size
+
     result = Array.new(self)
+    ref = Rubinius::Reflector.new(result)
+    tuple = ref.get(:@tuple)
 
     n.times do |i|
       r = i + random_generator.rand(size - i)
-      result.tuple.swap(i, r)
+      tuple.swap(i, r)
     end
 
     result[n..size] = []
@@ -629,8 +636,11 @@ def uniq!(&block)
     return if im.size == size
 
     array = im.to_array
-    @tuple = array.tuple
-    @start = array.start
+
+    ref = Rubinius::Reflector.new array
+
+    @tuple = ref.get(:@tuple)
+    @start = ref.get(:@start)
     @total = array.size
 
     self
@@ -667,19 +677,27 @@ def unshift(*values)
 
     return self if values.empty?
 
-    if @start > values.size
+    sz = values.size
+
+    if @start > sz
       # fit the new values in between 0 and @start if possible
-      @start -= values.size
-      @tuple.copy_from(values.tuple, 0, values.size, @start)
+      @start -= sz
+      if sz == 1
+        @tuple.put @start, values.at(0)
+      else
+        ref = Rubinius::Reflector.new values
+        @tuple.copy_from(ref.get(:@tuple), 0, sz, @start)
+      end
     else
-      new_tuple = Rubinius::Tuple.new @total + values.size
-      new_tuple.copy_from values.tuple, 0, values.size, 0
-      new_tuple.copy_from @tuple, @start, @total, values.size
+      ref = Rubinius::Reflector.new values
+      new_tuple = Rubinius::Tuple.new @total + sz
+      new_tuple.copy_from ref.get(:@tuple), 0, sz, 0
+      new_tuple.copy_from @tuple, @start, @total, sz
       @start = 0
       @tuple = new_tuple
     end
 
-    @total += values.size
+    @total += sz
     self
   end
 end

kernel/common/tuple.rb

@@ -13,9 +13,12 @@ class Tuple
     include Enumerable
 
     def self.[](*args)
-      start = args.start
+      ref = Rubinius::Reflector.new args
+      start = ref.get(:@start)
+      tuple = ref.get(:@tuple)
+
       tot = args.size
-      return new(tot).copy_from(args.tuple, start, tot, 0)
+      return new(tot).copy_from(tuple, start, tot, 0)
     end
 
     def to_s

rakelib/vm.rake

@@ -110,6 +110,7 @@ field_extract_headers = %w[
   vm/builtin/cache.hpp
   vm/builtin/atomic.hpp
   vm/builtin/character.hpp
+  vm/builtin/reflector.hpp
 ]
 
 transcoders_src_dir = File.expand_path "../../vendor/oniguruma/enc/trans", __FILE__

vm/builtin/reflector.cpp

@@ -0,0 +1,41 @@
+#include "vm.hpp"
+#include "vm/object_utils.hpp"
+
+#include "builtin/object.hpp"
+
+#include "builtin/reflector.hpp"
+
+#include "ontology.hpp"
+#include "builtin/class.hpp"
+#include "builtin/symbol.hpp"
+#include "primitives.hpp"
+
+namespace rubinius {
+  void Reflector::init(STATE) {
+    GO(reflector).set(ontology::new_class(state, "Reflector",
+                      G(object), G(rubinius)));
+    G(reflector)->set_object_type(state, Reflector::type);
+  }
+
+  Reflector* Reflector::create(STATE, Object* target) {
+    Reflector* ref = state->new_object<Reflector>(G(reflector));
+    ref->target(state, target);
+    return ref;
+  }
+
+  Object* Reflector::get(STATE, Symbol* name) {
+    if(name->is_ivar_p(state)->false_p()) return cNil;
+    return target_->get_ivar(state, name);
+  }
+
+  Object* Reflector::set(STATE, Symbol* name, Object* val) {
+    if(name->is_ivar_p(state)->false_p()) {
+      return Primitives::failure();
+    }
+
+    target_->check_frozen(state);
+    target_->set_ivar(state, name, val);
+
+    return val;
+  }
+}