Re-introduce small hash for memory savings and small speed up for sma…

…ll hashes
jruby · May 26, 2015 · 89c8525 · 89c8525
1 parent 25e14ae
commit 89c8525
Showing 1 changed file with 10 additions and 2 deletions.
diff --git a/core/src/main/java/org/jruby/ir/runtime/IRRuntimeHelpers.java b/core/src/main/java/org/jruby/ir/runtime/IRRuntimeHelpers.java
@@ -1031,9 +1031,17 @@ public static Encoding retrieveJCodingsEncoding(ThreadContext context, String na
 
     @JIT
     public static RubyHash constructHashFromArray(Ruby runtime, IRubyObject[] pairs) {
-        RubyHash hash = RubyHash.newHash(runtime);
+        int length = pairs.length / 2;
+        boolean useSmallHash = length <= 10;
+
+        RubyHash hash = useSmallHash ? RubyHash.newHash(runtime) : RubyHash.newSmallHash(runtime);
         for (int i = 0; i < pairs.length;) {
-            hash.fastASet(runtime, pairs[i++], pairs[i++], true);
+            if (useSmallHash) {
+                hash.fastASetSmall(runtime, pairs[i++], pairs[i++], true);
+            } else {
+                hash.fastASet(runtime, pairs[i++], pairs[i++], true);
+            }
+
         }
         return hash;
     }