reusable cpu timer

bindings/java/src/net/hyperic/sigar/CpuTimer.java

@@ -0,0 +1,109 @@
+package net.hyperic.sigar;
+
+import java.io.PrintStream;
+
+public class CpuTimer {
+    private Sigar sigar;
+    private long totalTime;
+    private long cpuTotal;
+    private long cpuUser;
+    private long cpuSys;
+    
+    private ThreadCpu cpu = new ThreadCpu();
+
+    private long startTime;
+
+    public CpuTimer() {
+        this(new Sigar());
+    }
+
+    public CpuTimer(Sigar sigar) {
+        this.sigar = sigar;
+    }
+
+    public void start() {
+        this.startTime = System.currentTimeMillis();
+        this.totalTime = 0;
+        this.cpuTotal = 0;
+        this.cpuUser  = 0;
+        this.cpuSys   = 0;
+
+        try {
+            this.cpu.gather(this.sigar, 0);
+        } catch (SigarException e) {
+            throw new IllegalArgumentException(e.toString());
+        }
+    }
+
+    public void stop() {
+        ThreadCpu diff = getDiff();
+
+        this.cpuTotal = diff.total;
+        this.cpuUser  = diff.user;
+        this.cpuSys   = diff.sys;
+
+        long stopTime = System.currentTimeMillis();
+        
+        long time = stopTime - this.startTime;
+
+        this.totalTime = time;
+    }
+
+    public ThreadCpu getDiff() {
+        long startTotal = this.cpu.total;
+        long startUser  = this.cpu.user;
+        long startSys   = this.cpu.sys;
+    
+        ThreadCpu diff = new ThreadCpu();
+
+        try {
+            this.cpu.gather(this.sigar, 0);
+        } catch (SigarException e) {
+            throw new IllegalArgumentException(e.toString());
+        }
+
+        diff.total = this.cpu.total - startTotal;
+        diff.user  = this.cpu.user - startUser;
+        diff.sys   = this.cpu.sys - startSys;
+
+        return diff;
+    }
+
+    public long getTotalTime() {
+        return this.totalTime;
+    }
+    
+    public long getCpuTotal() {
+        return this.cpuTotal / 1000000; //convert nanos to millis
+    }
+    
+    public long getCpuUser() {
+        return this.cpuUser / 1000000; //convert nanos to millis
+    }
+    
+    public long getCpuSys() {
+        return this.cpuSys / 1000000; //convert nanos to millis
+    }
+
+    public String format(long elap) {
+        String fraction = (elap % 1000) + "";
+        int pad = 3 - fraction.length();
+
+        StringBuffer buf = new StringBuffer()
+            .append(elap / 1000).append('.');
+
+        //for example, 15 millseconds formatted as ".015" rather than ".15"
+        while (pad-- > 0) {
+            buf.append("0");
+        }
+        buf.append(fraction).append(" seconds");
+        return buf.toString();
+    }
+
+    public void list(PrintStream out) {
+        out.println("real....." +
+                    format(getTotalTime()));
+        out.println("user....." + format(getCpuUser()));
+        out.println("sys......" + format(getCpuSys()));
+    }
+}