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1 files changed, 111 insertions, 0 deletions

diff --git a/simplemetrics/src/main/java/com/yahoo/metrics/simple/UntypedMetric.java b/simplemetrics/src/main/java/com/yahoo/metrics/simple/UntypedMetric.java
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+++ b/simplemetrics/src/main/java/com/yahoo/metrics/simple/UntypedMetric.java
@@ -0,0 +1,111 @@
+// Copyright 2016 Yahoo Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.metrics.simple;
+
+import java.util.logging.Logger;
+
+import org.HdrHistogram.DoubleHistogram;
+
+import com.yahoo.log.LogLevel;
+
+/**
+ * A gauge or a counter or... who knows? The class for storing a metric when the
+ * metric has not been declared.
+ *
+ * @author <a href="mailto:steinar@yahoo-inc.com">Steinar Knutsen</a>
+ */
+public class UntypedMetric {
+    private static final Logger log = Logger.getLogger(UntypedMetric.class.getName());
+
+    private long count = 0L;
+    private double current = 0.0d;
+    private double max;
+    private double min;
+    private double sum;
+    private AssumedType outputFormat = AssumedType.NONE;
+    private final DoubleHistogram histogram;
+    private final MetricSettings metricSettings;
+
+    public enum AssumedType { NONE, GAUGE, COUNTER };
+
+    UntypedMetric(MetricSettings metricSettings) {
+        this.metricSettings = metricSettings;
+        if (metricSettings == null || !metricSettings.isHistogram()) {
+            histogram = null;
+        } else {
+            histogram = new DoubleHistogram(metricSettings.getSignificantdigits());
+        }
+    }
+
+    void add(Number x) {
+        outputFormat = AssumedType.COUNTER;
+        count += x.longValue();
+    }
+
+    void put(Number x) {
+        outputFormat = AssumedType.GAUGE;
+        current = x.doubleValue();
+        if (histogram != null) {
+            histogram.recordValue(current);
+        }
+        if (count > 0) {
+            max = Math.max(current, max);
+            min = Math.min(current, min);
+            sum += current;
+        } else {
+            max = current;
+            min = current;
+            sum = current;
+        }
+        ++count;
+    }
+
+    UntypedMetric pruneData() {
+        UntypedMetric pruned = new UntypedMetric(null);
+        pruned.outputFormat = this.outputFormat;
+        pruned.current = this.current;
+        return pruned;
+    }
+
+    void merge(UntypedMetric other, boolean otherIsNewer) throws IllegalArgumentException {
+        if (outputFormat == AssumedType.NONE) {
+            outputFormat = other.outputFormat;
+        }
+        if (outputFormat != other.outputFormat) {
+            throw new IllegalArgumentException("Mismatching output formats: " + outputFormat + " and " + other.outputFormat + ".");
+        }
+        count += other.count;
+        if (otherIsNewer) {
+            current = other.current;
+        }
+        max = Math.max(other.max, max);
+        min = Math.min(other.min, min);
+        sum += other.sum;
+        if (histogram != null) {
+            // some config scenarios may lead to differing histogram settings,
+            // so doing this defensively
+            if (other.histogram != null) {
+                try {
+                    histogram.add(other.histogram);
+                } catch (ArrayIndexOutOfBoundsException e) {
+                    log.log(LogLevel.WARNING, "Had trouble merging histograms: " + e.getMessage());
+                }
+            }
+        }
+    }
+
+    public boolean isCounter() { return outputFormat == AssumedType.COUNTER; }
+
+    public long getCount() { return count; }
+    public double getLast() { return current; }
+    public double getMax() { return max; }
+    public double getMin() { return min; }
+    public double getSum() { return sum; }
+
+    MetricSettings getMetricDefinition() {
+        return metricSettings;
+    }
+
+    public DoubleHistogram getHistogram() {
+        return histogram;
+    }
+}