grapher: scroll continuously with time

Don't scale graph based on how much data will fit. This didn't work
very well and resulted in distracting, weird scale changes. We now
assume that scripts output their time (x axis) in milliseconds.

* grapher/Graph.hxx (setCurrentTime): New function.
* grapher/Graph.cxx (Graph::draw): Assume a fixed default scale of 1
  pixel = 5 milliseconds and don't do any autoscaling.
* grapher/GraphWidget.cxx (GraphWidget constructor): Set global time
  base on startup.
  (on_expose_event): Don't search graphs for earliest time.
* grapher/GraphWidget.hxx (_timeBaseInitialized): delete
* grapher/Time.hxx: new file; interface to timeval.

1 files changed, 83 insertions, 0 deletions

diff --git a/grapher/Time.hxx b/grapher/Time.hxx
new file mode 100644
index 00000000..7e16b7b2
--- /dev/null
+++ b/grapher/Time.hxx
@@ -0,0 +1,83 @@
+// systemtap grapher
+// Copyright (C) 2009 Red Hat Inc.
+//
+// This file is part of systemtap, and is free software.  You can
+// redistribute it and/or modify it under the terms of the GNU General
+// Public License (GPL); either version 2, or (at your option) any
+// later version.
+
+#ifndef SYSTEMTAP_GRAPHER_TIME_HXX
+#define SYSTEMTAP_GRAPHER_TIME_HXX 1
+
+#include <stdint.h>
+#include <sys/time.h>
+
+namespace systemtap
+{
+
+template<typename T>
+class Singleton
+{
+public:
+  static T& instance()
+  {
+    static T _instance;
+    return _instance;
+  }
+protected:
+  Singleton() {}
+private:
+  // Insure that singleton is constructed before main() is called.
+  struct InstanceBuilder
+  {
+    InstanceBuilder()
+    {
+      instance();
+    }
+  };
+  static InstanceBuilder _instanceBuilder;
+};
+
+template<typename T>
+typename Singleton<T>::InstanceBuilder Singleton<T>::_instanceBuilder;
+
+class Time : public Singleton<Time>
+{
+public:
+  Time()
+    : origin(0)
+  {
+    origin = getTime();
+  }
+
+  int64_t getTime()
+  {
+    timeval tval;
+    gettimeofday(&tval, 0);
+    int64_t now = toUs(tval);
+    return now - origin;
+  }
+
+  static int64_t get()
+  {
+    return instance().getTime();
+  }
+
+  static int64_t getAbs()
+  {
+    timeval tval;
+    gettimeofday(&tval, 0);
+    return toUs(tval);
+  }
+
+  static int64_t toUs(const timeval& t)
+  {
+    int64_t result = t.tv_sec * 1000000;
+    result += t.tv_usec;
+    return result;
+  }
+
+  int64_t origin;
+};
+}
+#endif