TraceBuffer implementation with tests

runtime/vm/trace_buffer_test.cc

Index: runtime/vm/trace_buffer_test.cc
diff --git a/runtime/vm/trace_buffer_test.cc b/runtime/vm/trace_buffer_test.cc
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index 0000000000000000000000000000000000000000..128487685fc2cd2dfee39f5c0311584dddae345d
--- /dev/null
+++ b/runtime/vm/trace_buffer_test.cc
@@ -0,0 +1,100 @@
+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#include "platform/assert.h"
+#include "vm/globals.h"
+#include "vm/json_stream.h"
+#include "vm/trace_buffer.h"
+#include "vm/unit_test.h"
+
+namespace dart {
+
+
+UNIT_TEST_CASE(TraceBufferEmpty) {
+  TraceBuffer* trace_buffer = new TraceBuffer(3);
+  {
+    JSONStream js;
+    trace_buffer->PrintToJSONStream(&js);
+    EXPECT_STREQ("{\"type\":\"TraceBuffer\",\"members\":[]}", js.ToCString());
+  }
+  delete trace_buffer;
+}
+
+
+UNIT_TEST_CASE(TraceBufferClear) {
+  TraceBuffer* trace_buffer = new TraceBuffer(3);
+  trace_buffer->Trace(kMicrosecondsPerSecond * 1, "abc");
+  trace_buffer->Clear();
+  {
+    JSONStream js;
+    trace_buffer->PrintToJSONStream(&js);
+    EXPECT_STREQ("{\"type\":\"TraceBuffer\",\"members\":[]}", js.ToCString());
+  }
+  delete trace_buffer;
+}
+
+
+UNIT_TEST_CASE(TraceBufferTrace) {
+  TraceBuffer* trace_buffer = new TraceBuffer(3);
+
+  trace_buffer->Trace(kMicrosecondsPerSecond * 1, "abc");
+  {
+    JSONStream js;
+    trace_buffer->PrintToJSONStream(&js);
+    EXPECT_STREQ("{\"type\":\"TraceBuffer\",\"members\":["
+                 "{\"type\":\"TraceBufferEntry\",\"time\":1.000000,"
+                 "\"message\":\"abc\"}]}", js.ToCString());
+  }
+  trace_buffer->Trace(kMicrosecondsPerSecond * 2, "def");
+  {
+    JSONStream js;
+    trace_buffer->PrintToJSONStream(&js);
+    EXPECT_STREQ("{\"type\":\"TraceBuffer\",\"members\":["
+                 "{\"type\":\"TraceBufferEntry\",\"time\":1.000000,"
+                 "\"message\":\"abc\"},"
+                 "{\"type\":\"TraceBufferEntry\",\"time\":2.000000,"
+                 "\"message\":\"def\"}]}", js.ToCString());
+  }
+  trace_buffer->Trace(kMicrosecondsPerSecond * 3, "ghi");
+  {
+    JSONStream js;
+    trace_buffer->PrintToJSONStream(&js);
+    EXPECT_STREQ("{\"type\":\"TraceBuffer\",\"members\":["
+                 "{\"type\":\"TraceBufferEntry\",\"time\":1.000000,"
+                 "\"message\":\"abc\"},"
+                 "{\"type\":\"TraceBufferEntry\",\"time\":2.000000,"
+                 "\"message\":\"def\"},"
+                 "{\"type\":\"TraceBufferEntry\",\"time\":3.000000,"
+                 "\"message\":\"ghi\"}]}", js.ToCString());
+  }
+  // This will overwrite the first Trace.
+  trace_buffer->Trace(kMicrosecondsPerSecond * 4, "jkl");
+  {
+    JSONStream js;
+    trace_buffer->PrintToJSONStream(&js);
+    EXPECT_STREQ("{\"type\":\"TraceBuffer\",\"members\":["
+                 "{\"type\":\"TraceBufferEntry\",\"time\":2.000000,"
+                 "\"message\":\"def\"},"
+                 "{\"type\":\"TraceBufferEntry\",\"time\":3.000000,"
+                 "\"message\":\"ghi\"},"
+                 "{\"type\":\"TraceBufferEntry\",\"time\":4.000000,"
+                 "\"message\":\"jkl\"}]}", js.ToCString());
+  }
+  delete trace_buffer;
+}
+
+
+UNIT_TEST_CASE(TraceBufferTraceF) {
+  TraceBuffer* trace_buffer = new TraceBuffer(3);
+  trace_buffer->TraceF("foo %d %s", 99, "bar");
+  {
+    JSONStream js;
+    trace_buffer->PrintToJSONStream(&js);
+    EXPECT_SUBSTRING("foo 99 bar", js.ToCString());
+  }
+  delete trace_buffer;
+}
+
+
+}  // namespace dart