dfs: update getBlockCacheStats to return a List of BlockCacheStats

Make available all underlying cache table stats for the used cache table
implementation.

The existing cache table stats implementation only allows a "global"
view of the cache table statistics; it does not differentiate between
all possible underlying cache tables used.

This change allows callers to get the block cache stats broken down
per underlying table. These cache stats are intended to be used for
monitoring all cache tables independently.

Existing usages of getBlockCacheStats now make use of
AggregatedBlockCacheStats.fromStatsList to aggregate the list of
BlockCacheStats into a single BlockCacheStats instance.

Change-Id: I261b3f2849857172397657e5c674b11e09807f27

3 files changed, 104 insertions, 34 deletions

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/dfs/AggregatedBlockCacheStatsTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/dfs/AggregatedBlockCacheStatsTest.java
index ac769498e2..2c4b432a01 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/dfs/AggregatedBlockCacheStatsTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/dfs/AggregatedBlockCacheStatsTest.java
@@ -24,9 +24,10 @@ public class AggregatedBlockCacheStatsTest {
 	@Test
 	public void getName() {
 		BlockCacheStats aggregatedBlockCacheStats = AggregatedBlockCacheStats
-				.fromStatsList("name", List.of());
+				.fromStatsList(List.of());
 
-		assertThat(aggregatedBlockCacheStats.getName(), equalTo("name"));
+		assertThat(aggregatedBlockCacheStats.getName(),
+				equalTo(AggregatedBlockCacheStats.class.getName()));
 	}
 
 	@Test
@@ -46,8 +47,7 @@ public class AggregatedBlockCacheStatsTest {
 		currentSizes[PackExt.INDEX.getPosition()] = 7;
 
 		BlockCacheStats aggregatedBlockCacheStats = AggregatedBlockCacheStats
-				.fromStatsList("name",
-						List.of(packStats, bitmapStats, indexStats));
+				.fromStatsList(List.of(packStats, bitmapStats, indexStats));
 
 		assertArrayEquals(aggregatedBlockCacheStats.getCurrentSize(),
 				currentSizes);
@@ -73,8 +73,7 @@ public class AggregatedBlockCacheStatsTest {
 		hitCounts[PackExt.INDEX.getPosition()] = 7;
 
 		BlockCacheStats aggregatedBlockCacheStats = AggregatedBlockCacheStats
-				.fromStatsList("name",
-						List.of(packStats, bitmapStats, indexStats));
+				.fromStatsList(List.of(packStats, bitmapStats, indexStats));
 
 		assertArrayEquals(aggregatedBlockCacheStats.getHitCount(), hitCounts);
 	}
@@ -99,8 +98,7 @@ public class AggregatedBlockCacheStatsTest {
 		missCounts[PackExt.INDEX.getPosition()] = 7;
 
 		BlockCacheStats aggregatedBlockCacheStats = AggregatedBlockCacheStats
-				.fromStatsList("name",
-						List.of(packStats, bitmapStats, indexStats));
+				.fromStatsList(List.of(packStats, bitmapStats, indexStats));
 
 		assertArrayEquals(aggregatedBlockCacheStats.getMissCount(), missCounts);
 	}
@@ -131,8 +129,7 @@ public class AggregatedBlockCacheStatsTest {
 		totalRequestCounts[PackExt.INDEX.getPosition()] = 14;
 
 		BlockCacheStats aggregatedBlockCacheStats = AggregatedBlockCacheStats
-				.fromStatsList("name",
-						List.of(packStats, bitmapStats, indexStats));
+				.fromStatsList(List.of(packStats, bitmapStats, indexStats));
 
 		assertArrayEquals(aggregatedBlockCacheStats.getTotalRequestCount(),
 				totalRequestCounts);
@@ -160,8 +157,7 @@ public class AggregatedBlockCacheStatsTest {
 		hitRatios[PackExt.INDEX.getPosition()] = 0;
 
 		BlockCacheStats aggregatedBlockCacheStats = AggregatedBlockCacheStats
-				.fromStatsList("Name",
-						List.of(packStats, bitmapStats, indexStats));
+				.fromStatsList(List.of(packStats, bitmapStats, indexStats));
 
 		assertArrayEquals(aggregatedBlockCacheStats.getHitRatio(), hitRatios);
 	}
@@ -186,8 +182,7 @@ public class AggregatedBlockCacheStatsTest {
 		evictions[PackExt.INDEX.getPosition()] = 7;
 
 		BlockCacheStats aggregatedBlockCacheStats = AggregatedBlockCacheStats
-				.fromStatsList("Name",
-						List.of(packStats, bitmapStats, indexStats));
+				.fromStatsList(List.of(packStats, bitmapStats, indexStats));
 
 		assertArrayEquals(aggregatedBlockCacheStats.getEvictions(), evictions);
 	}
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/dfs/ClockBlockCacheTableTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/dfs/ClockBlockCacheTableTest.java
index cb68bbc515..2e2f86bf80 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/dfs/ClockBlockCacheTableTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/dfs/ClockBlockCacheTableTest.java
@@ -1,8 +1,14 @@
 package org.eclipse.jgit.internal.storage.dfs;
 
 import static org.eclipse.jgit.internal.storage.dfs.DfsBlockCacheConfig.DEFAULT_NAME;
+import static org.eclipse.jgit.internal.storage.dfs.DfsBlockCacheTable.BlockCacheStats;
 import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.contains;
 import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.hasSize;
+import static org.hamcrest.Matchers.isA;
+
+import java.util.List;
 
 import org.junit.Test;
 
@@ -30,7 +36,8 @@ public class ClockBlockCacheTableTest {
 		ClockBlockCacheTable cacheTable = new ClockBlockCacheTable(
 				createBlockCacheConfig());
 
-		assertThat(cacheTable.getBlockCacheStats().getName(),
+		assertThat(cacheTable.getBlockCacheStats(), hasSize(1));
+		assertThat(cacheTable.getBlockCacheStats().get(0).getName(),
 				equalTo(DEFAULT_NAME));
 	}
 
@@ -39,7 +46,18 @@ public class ClockBlockCacheTableTest {
 		ClockBlockCacheTable cacheTable = new ClockBlockCacheTable(
 				createBlockCacheConfig().setName(NAME));
 
-		assertThat(cacheTable.getBlockCacheStats().getName(), equalTo(NAME));
+		assertThat(cacheTable.getBlockCacheStats(), hasSize(1));
+		assertThat(cacheTable.getBlockCacheStats().get(0).getName(),
+				equalTo(NAME));
+	}
+
+	@Test
+	public void getAllBlockCacheStats() {
+		ClockBlockCacheTable cacheTable = new ClockBlockCacheTable(
+				createBlockCacheConfig());
+
+		List<BlockCacheStats> blockCacheStats = cacheTable.getBlockCacheStats();
+		assertThat(blockCacheStats, contains(isA(BlockCacheStats.class)));
 	}
 
 	private static DfsBlockCacheConfig createBlockCacheConfig() {
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/dfs/PackExtBlockCacheTableTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/dfs/PackExtBlockCacheTableTest.java
index c5c964bcab..e7627bc4ab 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/dfs/PackExtBlockCacheTableTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/dfs/PackExtBlockCacheTableTest.java
@@ -10,8 +10,10 @@
 
 package org.eclipse.jgit.internal.storage.dfs;
 
+import static org.eclipse.jgit.internal.storage.dfs.DfsBlockCacheTable.BlockCacheStats;
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.hasSize;
 import static org.hamcrest.Matchers.sameInstance;
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertNotNull;
@@ -398,15 +400,51 @@ public class PackExtBlockCacheTableTest {
 	}
 
 	@Test
-	public void getBlockCacheStats_getName_returnsPackExtCacheTableName() {
-		DfsBlockCacheStats packStats = new DfsBlockCacheStats();
-		PackExtBlockCacheTable tables = PackExtBlockCacheTable.fromCacheTables(
-				cacheTableWithStats(/* name= */ "defaultName", packStats),
-				Map.of(PackExt.PACK, cacheTableWithStats(/* name= */ "packName",
-						packStats)));
+	public void getAllBlockCacheStats() {
+		String defaultTableName = "default table";
+		DfsBlockCacheStats defaultStats = new DfsBlockCacheStats(
+				defaultTableName);
+		incrementCounter(4,
+				() -> defaultStats.incrementHit(new TestKey(PackExt.REFTABLE)));
+
+		String packTableName = "pack table";
+		DfsBlockCacheStats packStats = new DfsBlockCacheStats(packTableName);
+		incrementCounter(5,
+				() -> packStats.incrementHit(new TestKey(PackExt.PACK)));
 
-		assertThat(tables.getBlockCacheStats().getName(),
-				equalTo("defaultName,packName"));
+		String bitmapTableName = "bitmap table";
+		DfsBlockCacheStats bitmapStats = new DfsBlockCacheStats(
+				bitmapTableName);
+		incrementCounter(6, () -> bitmapStats
+				.incrementHit(new TestKey(PackExt.BITMAP_INDEX)));
+
+		DfsBlockCacheTable defaultTable = cacheTableWithStats(defaultStats);
+		DfsBlockCacheTable packTable = cacheTableWithStats(packStats);
+		DfsBlockCacheTable bitmapTable = cacheTableWithStats(bitmapStats);
+		PackExtBlockCacheTable tables = PackExtBlockCacheTable
+				.fromCacheTables(defaultTable, Map.of(PackExt.PACK, packTable,
+						PackExt.BITMAP_INDEX, bitmapTable));
+
+		List<BlockCacheStats> statsList = tables.getBlockCacheStats();
+		assertThat(statsList, hasSize(3));
+
+		long[] defaultTableHitCounts = createEmptyStatsArray();
+		defaultTableHitCounts[PackExt.REFTABLE.getPosition()] = 4;
+		assertArrayEquals(
+				getCacheStatsByName(statsList, defaultTableName).getHitCount(),
+				defaultTableHitCounts);
+
+		long[] packTableHitCounts = createEmptyStatsArray();
+		packTableHitCounts[PackExt.PACK.getPosition()] = 5;
+		assertArrayEquals(
+				getCacheStatsByName(statsList, packTableName).getHitCount(),
+				packTableHitCounts);
+
+		long[] bitmapHitCounts = createEmptyStatsArray();
+		bitmapHitCounts[PackExt.BITMAP_INDEX.getPosition()] = 6;
+		assertArrayEquals(
+				getCacheStatsByName(statsList, bitmapTableName).getHitCount(),
+				bitmapHitCounts);
 	}
 
 	@Test
@@ -431,7 +469,8 @@ public class PackExtBlockCacheTableTest {
 								cacheTableWithStats(bitmapStats), PackExt.INDEX,
 								cacheTableWithStats(indexStats)));
 
-		assertArrayEquals(tables.getBlockCacheStats().getCurrentSize(),
+		assertArrayEquals(AggregatedBlockCacheStats
+				.fromStatsList(tables.getBlockCacheStats()).getCurrentSize(),
 				currentSizes);
 	}
 
@@ -460,7 +499,9 @@ public class PackExtBlockCacheTableTest {
 								cacheTableWithStats(bitmapStats), PackExt.INDEX,
 								cacheTableWithStats(indexStats)));
 
-		assertArrayEquals(tables.getBlockCacheStats().getHitCount(), hitCounts);
+		assertArrayEquals(AggregatedBlockCacheStats
+				.fromStatsList(tables.getBlockCacheStats()).getHitCount(),
+				hitCounts);
 	}
 
 	@Test
@@ -488,7 +529,8 @@ public class PackExtBlockCacheTableTest {
 								cacheTableWithStats(bitmapStats), PackExt.INDEX,
 								cacheTableWithStats(indexStats)));
 
-		assertArrayEquals(tables.getBlockCacheStats().getMissCount(),
+		assertArrayEquals(AggregatedBlockCacheStats
+				.fromStatsList(tables.getBlockCacheStats()).getMissCount(),
 				missCounts);
 	}
 
@@ -523,8 +565,9 @@ public class PackExtBlockCacheTableTest {
 								cacheTableWithStats(bitmapStats), PackExt.INDEX,
 								cacheTableWithStats(indexStats)));
 
-		assertArrayEquals(tables.getBlockCacheStats().getTotalRequestCount(),
-				totalRequestCounts);
+		assertArrayEquals(AggregatedBlockCacheStats
+				.fromStatsList(tables.getBlockCacheStats())
+				.getTotalRequestCount(), totalRequestCounts);
 	}
 
 	@Test
@@ -554,7 +597,9 @@ public class PackExtBlockCacheTableTest {
 								cacheTableWithStats(bitmapStats), PackExt.INDEX,
 								cacheTableWithStats(indexStats)));
 
-		assertArrayEquals(tables.getBlockCacheStats().getHitRatio(), hitRatios);
+		assertArrayEquals(AggregatedBlockCacheStats
+				.fromStatsList(tables.getBlockCacheStats()).getHitRatio(),
+				hitRatios);
 	}
 
 	@Test
@@ -582,10 +627,21 @@ public class PackExtBlockCacheTableTest {
 								cacheTableWithStats(bitmapStats), PackExt.INDEX,
 								cacheTableWithStats(indexStats)));
 
-		assertArrayEquals(tables.getBlockCacheStats().getEvictions(),
+		assertArrayEquals(AggregatedBlockCacheStats
+				.fromStatsList(tables.getBlockCacheStats()).getEvictions(),
 				evictions);
 	}
 
+	private BlockCacheStats getCacheStatsByName(
+			List<BlockCacheStats> blockCacheStats, String name) {
+		for (BlockCacheStats entry : blockCacheStats) {
+			if (entry.getName().equals(name)) {
+				return entry;
+			}
+		}
+		return null;
+	}
+
 	private static void incrementCounter(int amount, Runnable fn) {
 		for (int i = 0; i < amount; i++) {
 			fn.run();
@@ -597,15 +653,16 @@ public class PackExtBlockCacheTableTest {
 	}
 
 	private static DfsBlockCacheTable cacheTableWithStats(
-			DfsBlockCacheStats dfsBlockCacheStats) {
+			BlockCacheStats dfsBlockCacheStats) {
 		return cacheTableWithStats(CACHE_NAME, dfsBlockCacheStats);
 	}
 
 	private static DfsBlockCacheTable cacheTableWithStats(String name,
-			DfsBlockCacheStats dfsBlockCacheStats) {
+			BlockCacheStats dfsBlockCacheStats) {
 		DfsBlockCacheTable cacheTable = mock(DfsBlockCacheTable.class);
 		when(cacheTable.getName()).thenReturn(name);
-		when(cacheTable.getBlockCacheStats()).thenReturn(dfsBlockCacheStats);
+		when(cacheTable.getBlockCacheStats())
+				.thenReturn(List.of(dfsBlockCacheStats));
 		return cacheTable;
 	}