Add RegionStatisticsResolver to resolve the Region CacheStatistics (using Region.getStatistics()) from non-PARTITION Regions as well as rolling up and aggregating bucket stats for PARTITION Regions (using inner helper class, RegionStatisticsResolver.PartitionRegionCacheStatistics).

spring-geode-actuator/src/main/java/org/springframework/geode/boot/actuate/health/support/RegionStatisticsResolver.java

@@ -0,0 +1,161 @@
+/*
+ * Copyright 2018 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+package org.springframework.geode.boot.actuate.health.support;
+
+import java.util.Collections;
+import java.util.Optional;
+import java.util.Set;
+
+import org.apache.geode.cache.CacheStatistics;
+import org.apache.geode.cache.DataPolicy;
+import org.apache.geode.cache.Region;
+import org.apache.geode.cache.StatisticsDisabledException;
+import org.apache.geode.cache.partition.PartitionRegionHelper;
+import org.apache.geode.internal.cache.BucketRegion;
+import org.apache.geode.internal.cache.PartitionedRegion;
+import org.apache.geode.internal.cache.PartitionedRegionDataStore;
+import org.springframework.data.gemfire.util.RegionUtils;
+import org.springframework.util.Assert;
+
+/**
+ * The {@link RegionStatisticsResolver} class is a utility class for resolving the {@link CacheStatistics}
+ * for a {@link Region}, regardless of {@link Region} type, or more specifically {@link Region Region's}
+ * {@link DataPolicy data management policy}.
+ *
+ * @author John Blum
+ * @see org.apache.geode.cache.CacheStatistics
+ * @see org.apache.geode.cache.Region
+ * @see org.apache.geode.cache.partition.PartitionRegionHelper
+ * @see org.apache.geode.internal.cache.BucketRegion
+ * @see org.apache.geode.internal.cache.PartitionedRegion
+ * @since 1.0.0
+ */
+@SuppressWarnings("unused")
+public class RegionStatisticsResolver {
+
+	public static CacheStatistics resolve(Region<?, ?> region) {
+
+		return Optional.ofNullable(region)
+			.map(it -> PartitionRegionHelper.isPartitionedRegion(it)
+				? new PartitionRegionCacheStatistics(region)
+				: it.getStatistics())
+			.orElse(null);
+	}
+
+	protected static class PartitionRegionCacheStatistics implements CacheStatistics {
+
+		private final PartitionedRegion partitionRegion;
+
+		private float hitRatio = 0.0f;
+
+		private long hitCount = 0L;
+		private long lastAccessedTime = 0L;
+		private long lastModifiedTime = 0L;
+		private long missCount = 0L;
+
+		protected PartitionRegionCacheStatistics(Region<?, ?> region) {
+
+			Assert.isInstanceOf(PartitionedRegion.class, region, () ->
+				String.format("Region [%1$s] must be of type [%2$s]", RegionUtils.toRegionPath(region),
+					PartitionedRegion.class.getName()));
+
+			this.partitionRegion = computeStatistics((PartitionedRegion) region);
+		}
+
+		protected PartitionedRegion computeStatistics(PartitionedRegion region) {
+
+			float totalHitRatio = 0.0f;
+
+			int totalCount = 0;
+
+			long totalHitCount = 0L;
+			long maxLastAccessedTime = 0L;
+			long maxLastModifiedTime = 0L;
+			long totalMissCount = 0L;
+
+			Set<BucketRegion> bucketRegions = Optional.of(region)
+				.map(PartitionedRegion::getDataStore)
+				.map(PartitionedRegionDataStore::getAllLocalBucketRegions)
+				.orElseGet(Collections::emptySet);
+
+			for (BucketRegion bucket : bucketRegions) {
+
+				CacheStatistics bucketStatistics = bucket.getStatistics();
+
+				if (bucketStatistics != null) {
+
+					totalCount++;
+
+					totalHitCount += bucketStatistics.getHitCount();
+					totalHitRatio += bucketStatistics.getHitRatio();
+					maxLastAccessedTime = Math.max(maxLastAccessedTime, bucketStatistics.getLastAccessedTime());
+					maxLastModifiedTime = Math.max(maxLastModifiedTime, bucketStatistics.getLastModifiedTime());
+					totalMissCount += bucketStatistics.getMissCount();
+				}
+			}
+
+			if (totalCount > 0) {
+				this.hitCount = totalHitCount / totalCount;
+				this.hitRatio = totalHitRatio / totalCount;
+				this.lastAccessedTime = maxLastAccessedTime;
+				this.lastModifiedTime = maxLastModifiedTime;
+				this.missCount = totalMissCount / totalCount;
+			}
+
+			return region;
+		}
+
+		protected PartitionedRegion getPartitionRegion() {
+			return this.partitionRegion;
+		}
+
+		@Override
+		public long getHitCount() throws StatisticsDisabledException {
+			return this.hitCount;
+		}
+
+		@Override
+		public float getHitRatio() throws StatisticsDisabledException {
+			return this.hitRatio;
+		}
+
+		@Override
+		public long getLastAccessedTime() throws StatisticsDisabledException {
+			return this.lastAccessedTime;
+		}
+
+		@Override
+		public long getLastModifiedTime() {
+			return this.lastModifiedTime;
+		}
+
+		@Override
+		public long getMissCount() throws StatisticsDisabledException {
+			return this.missCount;
+		}
+
+		@Override
+		public void resetCounts() throws StatisticsDisabledException {
+
+			this.hitCount = 0L;
+			this.hitRatio = 0.0f;
+			this.lastAccessedTime = 0L;
+			this.lastModifiedTime = 0L;
+			this.missCount = 0L;
+		}
+	}
+}