Convert client_java to OpenMetrics

simpleclient/src/main/java/io/prometheus/client/Collector.java

@@ -1,6 +1,7 @@
 
 package io.prometheus.client;
 
+import java.util.ArrayList;
 import java.util.List;
 import java.util.regex.Pattern;
 
@@ -19,27 +20,58 @@ public abstract class Collector {
    */
   public abstract List<MetricFamilySamples> collect();
   public enum Type {
+    UNKNOWN, // This is untyped in Prometheus text format.
     COUNTER,
     GAUGE,
-    SUMMARY,
+    STATE_SET,
+    INFO,
     HISTOGRAM,
-    UNTYPED,
+    GAUGE_HISTOGRAM,
+    SUMMARY,
   }
 
   /**
    * A metric, and all of its samples.
    */
   static public class MetricFamilySamples {
     public final String name;
+    public final String unit;
     public final Type type;
     public final String help;
     public final List<Sample> samples;
 
-    public MetricFamilySamples(String name, Type type, String help, List<Sample> samples) {
+    public MetricFamilySamples(String name, String unit, Type type, String help, List<Sample> samples) {
+      if (!unit.isEmpty() && !name.endsWith("_" + unit)) {
+        throw new IllegalArgumentException("Metric's unit is not the suffix of the metric name: " + name);
+      }
+      if ((type == Type.INFO || type == Type.STATE_SET) && !unit.isEmpty()) {
+        throw new IllegalArgumentException("Metric is of a type that cannot have a unit: " + name);
+      }
+      List<Sample> mungedSamples = samples;
+      // Deal with _total from pre-OM automatically.
+      if (type == Type.COUNTER) {
+        if (name.endsWith("_total")) {
+          name = name.substring(0, name.length() - 6);
+        }
+        String withTotal = name + "_total";
+        mungedSamples = new ArrayList<Sample>(samples.size());
+        for (Sample s: samples) {
+          String n = s.name;
+          if (name.equals(n)) {
+            n = withTotal;
+          }
+          mungedSamples.add(new Sample(n, s.labelNames, s.labelValues, s.value, s.timestampMs));
+        }
+      }
       this.name = name;
+      this.unit = unit;
       this.type = type;
       this.help = help;
-      this.samples = samples;
+      this.samples = mungedSamples;
+    }
+
+    public MetricFamilySamples(String name, Type type, String help, List<Sample> samples) {
+      this(name, "", type, help, samples);
     }
 
     @Override
@@ -49,14 +81,18 @@ public boolean equals(Object obj) {
       }
       MetricFamilySamples other = (MetricFamilySamples) obj;
 
-      return other.name.equals(name) && other.type.equals(type)
-        && other.help.equals(help) && other.samples.equals(samples) ;
+      return other.name.equals(name)
+        && other.unit.equals(unit)
+        && other.type.equals(type)
+        && other.help.equals(help)
+        && other.samples.equals(samples);
     }
 
     @Override
     public int hashCode() {
       int hash = 1;
       hash = 37 * hash + name.hashCode();
+      hash = 37 * hash + unit.hashCode();
       hash = 37 * hash + type.hashCode();
       hash = 37 * hash + help.hashCode();
       hash = 37 * hash + samples.hashCode();
@@ -65,7 +101,7 @@ public int hashCode() {
 
     @Override
     public String toString() {
-      return "Name: " + name + " Type: " + type + " Help: " + help + 
+      return "Name: " + name + " Unit:" + unit + " Type: " + type + " Help: " + help +
         " Samples: " + samples;
     }
 

simpleclient/src/main/java/io/prometheus/client/CollectorRegistry.java

@@ -105,15 +105,32 @@ private List<String> collectorNames(Collector m) {
     List<String> names = new ArrayList<String>();
     for (Collector.MetricFamilySamples family : mfs) {
       switch (family.type) {
+        case COUNTER:
+          names.add(family.name + "_total");
+          names.add(family.name + "_created");
+          names.add(family.name);
+          break;
         case SUMMARY:
           names.add(family.name + "_count");
           names.add(family.name + "_sum");
+          names.add(family.name + "_created");
           names.add(family.name);
           break;
         case HISTOGRAM:
           names.add(family.name + "_count");
           names.add(family.name + "_sum");
           names.add(family.name + "_bucket");
+          names.add(family.name + "_created");
+          names.add(family.name);
+          break;
+        case GAUGE_HISTOGRAM:
+          names.add(family.name + "_gcount");
+          names.add(family.name + "_gsum");
+          names.add(family.name + "_bucket");
+          names.add(family.name);
+          break;
+        case INFO:
+          names.add(family.name + "_info");
           names.add(family.name);
           break;
         default:

simpleclient/src/main/java/io/prometheus/client/Counter.java

@@ -64,6 +64,12 @@
  * </pre>
  * These can be aggregated and processed together much more easily in the Prometheus
  * server than individual metrics for each labelset.
+ *
+ * If there is a suffix of <code>_total</code> on the metric name, it will be
+ * removed. When exposing the time series for counter value, a
+ * <code>_total</code> suffix will be added. This is for compatibility between
+ * OpenMetrics and the Prometheus text format, as OpenMetrics requires the
+ * <code>_total</code> suffix.
  */
 public class Counter extends SimpleCollector<Counter.Child> implements Collector.Describable {
 
@@ -74,6 +80,10 @@ public class Counter extends SimpleCollector<Counter.Child> implements Collector
   public static class Builder extends SimpleCollector.Builder<Builder, Counter> {
     @Override
     public Counter create() {
+      // Gracefully handle pre-OpenMetrics counters.
+      if (name.endsWith("_total")) {
+        name = name.substring(0, name.length() - 6);
+      }
       return new Counter(this);
     }
   }
@@ -108,6 +118,7 @@ protected Child newChild() {
    */
   public static class Child {
     private final DoubleAdder value = new DoubleAdder();
+    private final long created = System.currentTimeMillis();
     /**
      * Increment the counter by 1.
      */
@@ -130,6 +141,12 @@ public void inc(double amt) {
     public double get() {
       return value.sum();
     }
+    /**
+     * Get the created time of the counter in milliseconds.
+     */
+    public long created() {
+      return created;
+    }
   }
 
   // Convenience methods.
@@ -158,7 +175,8 @@ public double get() {
   public List<MetricFamilySamples> collect() {
     List<MetricFamilySamples.Sample> samples = new ArrayList<MetricFamilySamples.Sample>(children.size());
     for(Map.Entry<List<String>, Child> c: children.entrySet()) {
-      samples.add(new MetricFamilySamples.Sample(fullname, labelNames, c.getKey(), c.getValue().get()));
+      samples.add(new MetricFamilySamples.Sample(fullname + "_total", labelNames, c.getKey(), c.getValue().get()));
+      samples.add(new MetricFamilySamples.Sample(fullname + "_created", labelNames, c.getKey(), c.getValue().created() / 1000.0));
     }
     return familySamplesList(Type.COUNTER, samples);
   }

simpleclient/src/main/java/io/prometheus/client/CounterMetricFamily.java

@@ -37,7 +37,7 @@ public CounterMetricFamily(String name, String help, double value) {
     labelNames = Collections.emptyList();
     samples.add(
         new Sample(
-          name,
+          this.name + "_total",
           labelNames, 
           Collections.<String>emptyList(),
           value));
@@ -52,7 +52,7 @@ public CounterMetricFamily addMetric(List<String> labelValues, double value) {
     if (labelValues.size() != labelNames.size()) {
       throw new IllegalArgumentException("Incorrect number of labels.");
     }
-    samples.add(new Sample(name, labelNames, labelValues, value));
+    samples.add(new Sample(name + "_total", labelNames, labelValues, value));
     return this;
   }
 }