2 files changed, 71 insertions, 36 deletions

diff --git a/perf/jsonPerfSpec.js b/perf/jsonPerfSpec.js
index 01a489e2..edc4b6b2 100644
--- a/perf/jsonPerfSpec.js
+++ b/perf/jsonPerfSpec.js
@@ -1,28 +1,16 @@
 describe('json', function() {
 
   it('angular parser', function() {
-    var duration = time(function() {
-      expect(angular.fromJson(largeJsonString)).toBeTruthy();
-    }, 1);
-
-    dump(duration/1 + ' ms per iteration');
-  });
-
-
-  it('angular delegating to native parser', function() {
-    var duration = time(function() {
-      expect(angular.fromJson(largeJsonString, true)).toBeTruthy();
-    }, 100);
-
-    dump(duration/100 + ' ms per iteration');
-  });
-
-
-  it('native json', function() {
-    var duration = time(function() {
-      expect(JSON.parse(largeJsonString)).toBeTruthy();
-    }, 100);
-
-    dump(duration/100 + ' ms per iteration');
+    perf(
+      function angular() {
+        fromJson(largeJsonString);
+      },
+      function nativeDelegate() {
+        fromJson(largeJsonString, true);
+      },
+      function nativeJSON() {
+        JSON.parse(largeJsonString);
+      }
+    );
   });
 });
diff --git a/perf/testUtils.js b/perf/testUtils.js
index ca016c31..2fc4f8a2 100644
--- a/perf/testUtils.js
+++ b/perf/testUtils.js
@@ -1,20 +1,67 @@
 if (window.jstestdriver) {
   jstd = jstestdriver;
-  dump = angular.bind(jstd.console, jstd.console.log);
+  dump = bind(jstd.console, jstd.console.log);
 }
 
-function time(fn, times) {
-  times = times || 1;
+function time(fn) {
+  var count = 1,
+      targetTime = 500,
+      start = new Date().getTime(),
+      stop = start + targetTime,
+      elapsed,
+      end,
+      iterations,
+      pad = angularFilter.number;
 
-  var i,
-      start,
-      duration = 0;
-
-  for (i=0; i<times; i++) {
-    start = Date.now();
-    fn();
-    duration += Date.now() - start;
+  // do one iteration to guess how long it will take
+  fn();
+  while((end=new Date().getTime()) < stop ){
+    // how much time has elapsed since we started the test
+    elapsed = (end-start) || 1;
+    // guess how many more iterations we need before we reach
+    // the time limit. We do this so that we spend most of our
+    // time in tight loop
+    iterations = Math.ceil(
+        // how much more time we need
+        (targetTime - elapsed)
+        /
+        2 // to prevent overrun guess low
+        /
+        // this is how much the cost is so far per iteration
+        (elapsed / count)
+      );
+    count += iterations;
+    while(iterations--) {
+      fn();
+    }
   }
+  elapsed = end - start;
+  return {
+    count: count,
+    total: elapsed,
+    time: elapsed / count,
+    name: fn.name,
+    msg: '' + pad(elapsed / count, 3)
+      + ' ms [ ' + pad(1 / elapsed * count * 1000, 0) + ' ops/sec ] '
+      + '(' + elapsed + ' ms/' + count + ')'
+  };
+
+}
 
-  return duration;
-}
\ No newline at end of file
+function perf() {
+  var log = [],
+      summary = [],
+      i,
+      baseline,
+      pad = angularFilter.number;
+
+  for (i = 0; i < arguments.length; i++) {
+    var fn = arguments[i];
+    var info = time(fn);
+    if (baseline === undefined) baseline = info.time;
+    summary.push(info.name + ': ' + pad(baseline / info.time, 2) + ' X');
+    log.push('\n        ' + info.name + ': ' + info.msg);
+  }
+  log.unshift(summary.join(' - '));
+  dump(log.join(' '));
+}