1 files changed, 128 insertions, 0 deletions
diff --git a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/container/metrics/Metrics.java b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/container/metrics/Metrics.java
new file mode 100644
index 00000000000..ec3b2d347e5
--- /dev/null
+++ b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/container/metrics/Metrics.java
@@ -0,0 +1,128 @@
+// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.hosted.node.admin.container.metrics;
+
+import com.google.inject.Inject;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.stream.Collectors;
+
+/**
+ * Stores the latest metric for the given application, name, dimension triplet in memory
+ *
+ * @author freva
+ */
+public class Metrics {
+    // Application names used
+    public static final String APPLICATION_HOST = "vespa.host";
+    public static final String APPLICATION_NODE = "vespa.node";
+
+    private final Object monitor = new Object();
+    private final Map<DimensionType, Map<String, ApplicationMetrics>> metrics = new HashMap<>();
+
+    @Inject
+    public Metrics() { }
+
+    /**
+     * Creates a counter metric under vespa.host application, with no dimensions and default dimension type
+     * See {@link #declareCounter(String, String, Dimensions, DimensionType)}
+     */
+    public Counter declareCounter(String name) {
+        return declareCounter(name, Dimensions.NONE);
+    }
+
+    /**
+     * Creates a counter metric under vespa.host application, with the given dimensions and default dimension type
+     * See {@link #declareCounter(String, String, Dimensions, DimensionType)}
+     */
+    public Counter declareCounter(String name, Dimensions dimensions) {
+        return declareCounter(APPLICATION_HOST, name, dimensions, DimensionType.DEFAULT);
+    }
+
+    /** Creates a counter metric. This method is idempotent. */
+    public Counter declareCounter(String application, String name, Dimensions dimensions, DimensionType type) {
+        synchronized (monitor) {
+            return (Counter) getOrCreateApplicationMetrics(application, type)
+                    .computeIfAbsent(dimensions, d -> new HashMap<>())
+                    .computeIfAbsent(name, n -> new Counter());
+        }
+    }
+
+    /**
+     * Creates a gauge metric under vespa.host application, with no dimensions and default dimension type
+     * See {@link #declareGauge(String, String, Dimensions, DimensionType)}
+     */
+    public Gauge declareGauge(String name) {
+        return declareGauge(name, Dimensions.NONE);
+    }
+
+    /**
+     * Creates a gauge metric under vespa.host application, with the given dimensions and default dimension type
+     * See {@link #declareGauge(String, String, Dimensions, DimensionType)}
+     */
+    public Gauge declareGauge(String name, Dimensions dimensions) {
+        return declareGauge(APPLICATION_HOST, name, dimensions, DimensionType.DEFAULT);
+    }
+
+    /** Creates a gauge metric. This method is idempotent */
+    public Gauge declareGauge(String application, String name, Dimensions dimensions, DimensionType type) {
+        synchronized (monitor) {
+            return (Gauge) getOrCreateApplicationMetrics(application, type)
+                    .computeIfAbsent(dimensions, d -> new HashMap<>())
+                    .computeIfAbsent(name, n -> new Gauge());
+        }
+    }
+
+    public List<DimensionMetrics> getDefaultMetrics() {
+        return getMetricsByType(DimensionType.DEFAULT);
+    }
+
+    public List<DimensionMetrics> getMetricsByType(DimensionType type) {
+        synchronized (monitor) {
+            List<DimensionMetrics> dimensionMetrics = new ArrayList<>();
+            metrics.getOrDefault(type, Map.of())
+                    .forEach((application, applicationMetrics) -> applicationMetrics.metricsByDimensions().entrySet().stream()
+                    .map(entry -> new DimensionMetrics(application, entry.getKey(),
+                            entry.getValue().entrySet().stream().collect(Collectors.toMap(Map.Entry::getKey, value -> value.getValue().getValue()))))
+                    .forEach(dimensionMetrics::add));
+            return dimensionMetrics;
+        }
+    }
+
+    public void deleteMetricByDimension(String name,  Dimensions dimensionsToRemove, DimensionType type) {
+        synchronized (monitor) {
+            Optional.ofNullable(metrics.get(type))
+                    .map(m -> m.get(name))
+                    .map(ApplicationMetrics::metricsByDimensions)
+                    .ifPresent(m -> m.remove(dimensionsToRemove));
+        }
+    }
+
+    Map<Dimensions, Map<String, MetricValue>> getOrCreateApplicationMetrics(String application, DimensionType type) {
+        return metrics.computeIfAbsent(type, m -> new HashMap<>())
+                .computeIfAbsent(application, app -> new ApplicationMetrics())
+                .metricsByDimensions();
+    }
+
+    // "Application" is the monitoring application, not Vespa application
+    private static class ApplicationMetrics {
+        private final Map<Dimensions, Map<String, MetricValue>> metricsByDimensions = new LinkedHashMap<>();
+
+        Map<Dimensions, Map<String, MetricValue>> metricsByDimensions() {
+            return metricsByDimensions;
+        }
+    }
+
+    // Used to distinguish whether metrics have been populated with all tag vaules
+    public enum DimensionType {
+        /** Default metrics get added default dimensions set in check config */
+        DEFAULT,
+
+        /** Pretagged metrics will only get the dimensions explicitly set when creating the counter/gauge */
+        PRETAGGED
+    }
+}