Add Metrics for heap high water marks

runtime/vm/metrics.h

 // Copyright (c) 2014, 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.
 
 #ifndef VM_METRICS_H_
 #define VM_METRICS_H_
 
 #include "vm/allocation.h"
 
 namespace dart {
 
 class Isolate;
 class JSONStream;
 
 // Metrics for each isolate.
 #define ISOLATE_METRIC_LIST(V)                                                 \
   V(MetricHeapOldUsed, HeapOldUsed, "heap.old.used", kByte)                    \
   V(MetricHeapOldCapacity, HeapOldCapacity, "heap.old.capacity", kByte)        \
+  V(MaxMetric, HeapOldCapacityMax, "heap.old.capacity.max", kByte)             \
   V(MetricHeapOldExternal, HeapOldExternal, "heap.old.external", kByte)        \
   V(MetricHeapNewUsed, HeapNewUsed, "heap.new.used", kByte)                    \
   V(MetricHeapNewCapacity, HeapNewCapacity, "heap.new.capacity", kByte)        \
-  V(MetricHeapNewExternal, HeapNewExternal, "heap.new.external", kByte)        \
+  V(MaxMetric, HeapNewCapacityMax, "heap.new.capacity.max", kByte)             \
+  V(MetricHeapNewExternal, HeapNewExternal, "heap.new.external", kByte)
 
 #define VM_METRIC_LIST(V)                                                      \
-  V(MetricIsolateCount, IsolateCount, "vm.isolate.count", kCounter)            \
+  V(MetricIsolateCount, IsolateCount, "vm.isolate.count", kCounter)
 
 class Metric {
  public:
   enum Unit {
     kCounter,
     kByte,
   };
 
   Metric();
 
@@ skipping 59 matching lines @@
   void RegisterWithIsolate();
   void DeregisterWithIsolate();
   void RegisterWithVM();
   void DeregisterWithVM();
 
   static Metric* vm_list_head_;
   DISALLOW_COPY_AND_ASSIGN(Metric);
 };
 
 
+// A Metric class that reports the maximum value observed.
+// Initial maximum is kMinInt64.
+class MaxMetric : public Metric {
+ public:
+  MaxMetric();
+
+  void SetValue(int64_t new_value);
+};
+
+
+// A Metric class that reports the minimum value observed.
+// Initial minimum is kMaxInt64.
+class MinMetric : public Metric {
+ public:
+  MinMetric();
+
+  void SetValue(int64_t new_value);
+};
+
+
 class MetricHeapOldUsed : public Metric {
  protected:
   virtual int64_t Value() const;
 };
 
 
 class MetricHeapOldCapacity : public Metric {
  protected:
   virtual int64_t Value() const;
 };
@@ skipping 25 matching lines @@
 
 class MetricIsolateCount : public Metric {
  protected:
   virtual int64_t Value() const;
 };
 
 
 }  // namespace dart
 
 #endif  // VM_METRICS_H_