Refactor DocStats and StoreStats with Builder pattern

CHANGELOG.md

@@ -34,6 +34,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Change the default value of doc_values in WildcardFieldMapper to true. ([#19796](https://github.com/opensearch-project/OpenSearch/pull/19796))
 - Make Engine#loadHistoryUUID() protected and Origin#isFromTranslog() public ([#19753](https://github.com/opensearch-project/OpenSearch/pull/19752))
 - Bump opensearch-protobufs dependency to 0.23.0 and update transport-grpc module compatibility ([#19831](https://github.com/opensearch-project/OpenSearch/pull/19831))
+- Refactor the DocStats and StoreStats class to use the Builder pattern instead of constructors ([#19863](https://github.com/opensearch-project/OpenSearch/pull/19863))
 
 ### Fixed
 - Fix Allocation and Rebalance Constraints of WeightFunction are incorrectly reset ([#19012](https://github.com/opensearch-project/OpenSearch/pull/19012))
@@ -74,6 +75,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ### Deprecated
 - Deprecated existing constructors in ThreadPoolStats.Stats in favor of the new Builder ([#19317](https://github.com/opensearch-project/OpenSearch/pull/19317))
 - Deprecated existing constructors in IndexingStats.Stats in favor of the new Builder ([#19306](https://github.com/opensearch-project/OpenSearch/pull/19306))
+- Deprecated existing constructors in DocStats and StoreStats in favor of the new Builder ([#19863](https://github.com/opensearch-project/OpenSearch/pull/19863))
 
 ### Removed
 

modules/store-subdirectory/src/test/java/org/opensearch/plugin/store/subdirectory/SubdirectoryStorePluginTests.java

@@ -87,7 +87,7 @@ public void testStats() throws IOException {
 
         final long otherStatsBytes = randomLongBetween(0L, Integer.MAX_VALUE);
         final long otherStatsReservedBytes = randomBoolean() ? StoreStats.UNKNOWN_RESERVED_BYTES : randomLongBetween(0L, Integer.MAX_VALUE);
-        stats.add(new StoreStats(otherStatsBytes, otherStatsReservedBytes));
+        stats.add(new StoreStats.Builder().sizeInBytes(otherStatsBytes).reservedSize(otherStatsReservedBytes).build());
         assertEquals(initialStoreSize + otherStatsBytes, stats.getSize().getBytes());
         assertEquals(Math.max(reservedBytes, 0L) + Math.max(otherStatsReservedBytes, 0L), stats.getReservedSize().getBytes());
 

server/src/main/java/org/opensearch/index/engine/Engine.java

@@ -275,7 +275,7 @@ protected final DocsStats docsStats(IndexReader indexReader) {
                 logger.trace(() -> new ParameterizedMessage("failed to get size for [{}]", info.info.name), e);
             }
         }
-        return new DocsStats(numDocs, numDeletedDocs, sizeInBytes);
+        return new DocsStats.Builder().count(numDocs).deleted(numDeletedDocs).totalSizeInBytes(sizeInBytes).build();
     }
 
     /**

server/src/main/java/org/opensearch/index/shard/DocsStats.java

@@ -58,12 +58,28 @@ public DocsStats() {
 
     }
 
+    /**
+     * Private constructor that takes a builder.
+     * This is the sole entry point for creating a new DocsStats object.
+     * @param builder The builder instance containing all the values.
+     */
+    private DocsStats(Builder builder) {
+        this.count = builder.count;
+        this.deleted = builder.deleted;
+        this.totalSizeInBytes = builder.totalSizeInBytes;
+    }
+
     public DocsStats(StreamInput in) throws IOException {
         count = in.readVLong();
         deleted = in.readVLong();
         totalSizeInBytes = in.readVLong();
     }
 
+    /**
+     * This constructor will be deprecated starting in version 3.4.0.
+     * Use {@link Builder} instead.
+     */
+    @Deprecated
     public DocsStats(long count, long deleted, long totalSizeInBytes) {
         this.count = count;
         this.deleted = deleted;
@@ -107,6 +123,41 @@ public long getAverageSizeInBytes() {
         return totalDocs == 0 ? 0 : totalSizeInBytes / totalDocs;
     }
 
+    /**
+     * Builder for the {@link DocsStats} class.
+     * Provides a fluent API for constructing a DocsStats object.
+     */
+    public static class Builder {
+        private long count = 0;
+        private long deleted = 0;
+        private long totalSizeInBytes = 0;
+
+        public Builder() {}
+
+        public Builder count(long count) {
+            this.count = count;
+            return this;
+        }
+
+        public Builder deleted(long deleted) {
+            this.deleted = deleted;
+            return this;
+        }
+
+        public Builder totalSizeInBytes(long totalSizeInBytes) {
+            this.totalSizeInBytes = totalSizeInBytes;
+            return this;
+        }
+
+        /**
+         * Creates a {@link DocsStats} object from the builder's current state.
+         * @return A new DocsStats instance.
+         */
+        public DocsStats build() {
+            return new DocsStats(this);
+        }
+    }
+
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         out.writeVLong(count);

server/src/main/java/org/opensearch/index/store/Store.java

@@ -469,7 +469,7 @@ public CheckIndex.Status checkIndex(PrintStream out) throws IOException {
      */
     public StoreStats stats(long reservedBytes) throws IOException {
         ensureOpen();
-        return new StoreStats(directory.estimateSize(), reservedBytes);
+        return new StoreStats.Builder().sizeInBytes(directory.estimateSize()).reservedSize(reservedBytes).build();
     }
 
     /**

server/src/main/java/org/opensearch/index/store/StoreStats.java

@@ -62,15 +62,26 @@ public StoreStats() {
 
     }
 
+    /**
+     * Private constructor that takes a builder.
+     * This is the sole entry point for creating a new StoreStats object.
+     * @param builder The builder instance containing all the values.
+     */
+    private StoreStats(Builder builder) {
+        this.sizeInBytes = builder.sizeInBytes;
+        this.reservedSize = builder.reservedSize;
+    }
+
     public StoreStats(StreamInput in) throws IOException {
         sizeInBytes = in.readVLong();
         reservedSize = in.readZLong();
     }
 
     /**
-     * @param sizeInBytes the size of the store in bytes
-     * @param reservedSize a prediction of how much larger the store is expected to grow, or {@link StoreStats#UNKNOWN_RESERVED_BYTES}.
-     */
+     * This constructor will be deprecated starting in version 3.4.0.
+     * Use {@link Builder} instead.
+      */
+    @Deprecated
     public StoreStats(long sizeInBytes, long reservedSize) {
         assert reservedSize == UNKNOWN_RESERVED_BYTES || reservedSize >= 0 : reservedSize;
         this.sizeInBytes = sizeInBytes;
@@ -114,6 +125,42 @@ public ByteSizeValue getReservedSize() {
         return new ByteSizeValue(reservedSize);
     }
 
+    /**
+     * Builder for the {@link StoreStats} class.
+     * Provides a fluent API for constructing a StoreStats object.
+     */
+    public static class Builder {
+        private long sizeInBytes = 0;
+        private long reservedSize = 0;
+
+        public Builder() {}
+
+        /**
+         * @param bytes the size of the store in bytes
+         */
+        public Builder sizeInBytes(long bytes) {
+            this.sizeInBytes = bytes;
+            return this;
+        }
+
+        /**
+         * @param size a prediction of how much larger the store is expected to grow, or {@link StoreStats#UNKNOWN_RESERVED_BYTES}.
+         */
+        public Builder reservedSize(long size) {
+            assert size == UNKNOWN_RESERVED_BYTES || size >= 0 : size;
+            this.reservedSize = size;
+            return this;
+        }
+
+        /**
+         * Creates a {@link StoreStats} object from the builder's current state.
+         * @return A new StoreStats instance.
+         */
+        public StoreStats build() {
+            return new StoreStats(this);
+        }
+    }
+
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         out.writeVLong(sizeInBytes);

server/src/test/java/org/opensearch/action/admin/cluster/node/stats/NodeStatsTests.java

@@ -1147,10 +1147,10 @@ public void testOldVersionNodes() throws IOException {
         long numDeletedDocs = randomLongBetween(0, 100);
         CommonStats commonStats = new CommonStats(CommonStatsFlags.NONE);
 
-        commonStats.docs = new DocsStats(numDocs, numDeletedDocs, 0);
-        commonStats.store = new StoreStats(100, 0L);
+        commonStats.docs = new DocsStats.Builder().count(numDocs).deleted(numDeletedDocs).totalSizeInBytes(0).build();
+        commonStats.store = new StoreStats.Builder().sizeInBytes(100).reservedSize(0L).build();
         commonStats.indexing = new IndexingStats();
-        DocsStats hostDocStats = new DocsStats(numDocs, numDeletedDocs, 0);
+        DocsStats hostDocStats = new DocsStats.Builder().count(numDocs).deleted(numDeletedDocs).totalSizeInBytes(0).build();
 
         CommonStatsFlags commonStatsFlags = new CommonStatsFlags();
         commonStatsFlags.clear();
@@ -1193,8 +1193,8 @@ public void testNodeIndicesStatsSerialization() throws IOException {
         levelParams.add(NodeIndicesStats.StatsLevel.NODE);
         CommonStats commonStats = new CommonStats(CommonStatsFlags.NONE);
 
-        commonStats.docs = new DocsStats(numDocs, numDeletedDocs, 0);
-        commonStats.store = new StoreStats(100, 0L);
+        commonStats.docs = new DocsStats.Builder().count(numDocs).deleted(numDeletedDocs).totalSizeInBytes(0).build();
+        commonStats.store = new StoreStats.Builder().sizeInBytes(100).reservedSize(0L).build();
         commonStats.indexing = new IndexingStats();
 
         CommonStatsFlags commonStatsFlags = new CommonStatsFlags();
@@ -1244,8 +1244,8 @@ public void testNodeIndicesStatsToXContent() {
         levelParams.add(NodeIndicesStats.StatsLevel.NODE);
         CommonStats commonStats = new CommonStats(CommonStatsFlags.NONE);
 
-        commonStats.docs = new DocsStats(numDocs, numDeletedDocs, 0);
-        commonStats.store = new StoreStats(100, 0L);
+        commonStats.docs = new DocsStats.Builder().count(numDocs).deleted(numDeletedDocs).totalSizeInBytes(0).build();
+        commonStats.store = new StoreStats.Builder().sizeInBytes(100).reservedSize(0L).build();
         commonStats.indexing = new IndexingStats();
 
         CommonStatsFlags commonStatsFlags = new CommonStatsFlags();
@@ -1364,8 +1364,13 @@ public void testNodeIndicesStatsWithAndWithoutAggregations() throws IOException
 
     private CommonStats createRandomCommonStats() {
         CommonStats commonStats = new CommonStats(CommonStatsFlags.NONE);
-        commonStats.docs = new DocsStats(randomLongBetween(0, 10000), randomLongBetween(0, 100), randomLongBetween(0, 1000));
-        commonStats.store = new StoreStats(randomLongBetween(0, 100), randomLongBetween(0, 1000));
+        commonStats.docs = new DocsStats.Builder().count(randomLongBetween(0, 10000))
+            .deleted(randomLongBetween(0, 100))
+            .totalSizeInBytes(randomLongBetween(0, 1000))
+            .build();
+        commonStats.store = new StoreStats.Builder().sizeInBytes(randomLongBetween(0, 100))
+            .reservedSize(randomLongBetween(0, 1000))
+            .build();
         commonStats.indexing = new IndexingStats();
         commonStats.completion = new CompletionStats();
         commonStats.flush = new FlushStats(randomLongBetween(0, 100), randomLongBetween(0, 100), randomLongBetween(0, 100));

server/src/test/java/org/opensearch/action/admin/cluster/stats/ClusterStatsNodesTests.java

@@ -362,8 +362,13 @@ private ClusterStatsNodeResponse createClusterStatsNodeResponse(
 
     private CommonStats createRandomCommonStats() {
         CommonStats commonStats = new CommonStats(CommonStatsFlags.NONE);
-        commonStats.docs = new DocsStats(randomLongBetween(0, 10000), randomLongBetween(0, 100), randomLongBetween(0, 1000));
-        commonStats.store = new StoreStats(randomLongBetween(0, 100), randomLongBetween(0, 1000));
+        commonStats.docs = new DocsStats.Builder().count(randomLongBetween(0, 10000))
+            .deleted(randomLongBetween(0, 100))
+            .totalSizeInBytes(randomLongBetween(0, 1000))
+            .build();
+        commonStats.store = new StoreStats.Builder().sizeInBytes(randomLongBetween(0, 100))
+            .reservedSize(randomLongBetween(0, 1000))
+            .build();
         commonStats.indexing = new IndexingStats();
         commonStats.completion = new CompletionStats();
         commonStats.flush = new FlushStats(randomLongBetween(0, 100), randomLongBetween(0, 100), randomLongBetween(0, 100));

server/src/test/java/org/opensearch/action/admin/cluster/stats/ClusterStatsResponseTests.java

@@ -230,8 +230,13 @@ private ClusterStatsNodeResponse createClusterStatsNodeResponse(DiscoveryNode no
 
     private CommonStats createRandomCommonStats() {
         CommonStats commonStats = new CommonStats(CommonStatsFlags.NONE);
-        commonStats.docs = new DocsStats(randomLongBetween(0, 10000), randomLongBetween(0, 100), randomLongBetween(0, 1000));
-        commonStats.store = new StoreStats(randomLongBetween(0, 100), randomLongBetween(0, 1000));
+        commonStats.docs = new DocsStats.Builder().count(randomLongBetween(0, 10000))
+            .deleted(randomLongBetween(0, 100))
+            .totalSizeInBytes(randomLongBetween(0, 1000))
+            .build();
+        commonStats.store = new StoreStats.Builder().sizeInBytes(randomLongBetween(0, 100))
+            .reservedSize(randomLongBetween(0, 1000))
+            .build();
         commonStats.indexing = new IndexingStats();
         commonStats.completion = new CompletionStats();
         commonStats.flush = new FlushStats(randomLongBetween(0, 100), randomLongBetween(0, 100), randomLongBetween(0, 100));

server/src/test/java/org/opensearch/action/admin/indices/rollover/TransportRolloverActionTests.java

@@ -148,15 +148,19 @@ public void testEvaluateConditions() {
         final Set<Condition<?>> conditions = Sets.newHashSet(maxDocsCondition, maxAgeCondition, maxSizeCondition);
         Map<String, Boolean> results = evaluateConditions(
             conditions,
-            new DocsStats(matchMaxDocs, 0L, ByteSizeUnit.MB.toBytes(120)),
+            new DocsStats.Builder().count(matchMaxDocs).deleted(0L).totalSizeInBytes(ByteSizeUnit.MB.toBytes(120)).build(),
             metadata
         );
         assertThat(results.size(), equalTo(3));
         for (Boolean matched : results.values()) {
             assertThat(matched, equalTo(true));
         }
 
-        results = evaluateConditions(conditions, new DocsStats(notMatchMaxDocs, 0, notMatchMaxSize.getBytes()), metadata);
+        results = evaluateConditions(
+            conditions,
+            new DocsStats.Builder().count(notMatchMaxDocs).deleted(0).totalSizeInBytes(notMatchMaxSize.getBytes()).build(),
+            metadata
+        );
         assertThat(results.size(), equalTo(3));
         for (Map.Entry<String, Boolean> entry : results.entrySet()) {
             if (entry.getKey().equals(maxAgeCondition.toString())) {
@@ -211,7 +215,12 @@ public void testEvaluateWithoutMetadata() {
 
         long matchMaxDocs = randomIntBetween(100, 1000);
         final Set<Condition<?>> conditions = Sets.newHashSet(maxDocsCondition, maxAgeCondition, maxSizeCondition);
-        Map<String, Boolean> results = evaluateConditions(conditions, new DocsStats(matchMaxDocs, 0L, ByteSizeUnit.MB.toBytes(120)), null);
+
+        Map<String, Boolean> results = evaluateConditions(
+            conditions,
+            new DocsStats.Builder().count(matchMaxDocs).deleted(0L).totalSizeInBytes(ByteSizeUnit.MB.toBytes(120)).build(),
+            null
+        );
         assertThat(results.size(), equalTo(3));
         results.forEach((k, v) -> assertFalse(v));
 
@@ -390,10 +399,14 @@ public void testResolveIndices() {
 
     private IndicesStatsResponse createIndicesStatResponse(String indexName, long totalDocs, long primariesDocs) {
         final CommonStats primaryStats = mock(CommonStats.class);
-        when(primaryStats.getDocs()).thenReturn(new DocsStats(primariesDocs, 0, between(1, 10000)));
+        when(primaryStats.getDocs()).thenReturn(
+            new DocsStats.Builder().count(primariesDocs).deleted(0).totalSizeInBytes(between(1, 10000)).build()
+        );
 
         final CommonStats totalStats = mock(CommonStats.class);
-        when(totalStats.getDocs()).thenReturn(new DocsStats(totalDocs, 0, between(1, 10000)));
+        when(totalStats.getDocs()).thenReturn(
+            new DocsStats.Builder().count(totalDocs).deleted(0).totalSizeInBytes(between(1, 10000)).build()
+        );
 
         final IndicesStatsResponse response = mock(IndicesStatsResponse.class);
         when(response.getPrimaries()).thenReturn(primaryStats);
@@ -422,10 +435,14 @@ private IndicesStatsResponse createAliasToMultipleIndicesStatsResponse(Map<Strin
 
     private IndexStats createIndexStats(long primaries, long total) {
         final CommonStats primariesCommonStats = mock(CommonStats.class);
-        when(primariesCommonStats.getDocs()).thenReturn(new DocsStats(primaries, 0, between(1, 10000)));
+        when(primariesCommonStats.getDocs()).thenReturn(
+            new DocsStats.Builder().count(primaries).deleted(0).totalSizeInBytes(between(1, 10000)).build()
+        );
 
         final CommonStats totalCommonStats = mock(CommonStats.class);
-        when(totalCommonStats.getDocs()).thenReturn(new DocsStats(total, 0, between(1, 10000)));
+        when(totalCommonStats.getDocs()).thenReturn(
+            new DocsStats.Builder().count(total).deleted(0).totalSizeInBytes(between(1, 10000)).build()
+        );
 
         IndexStats indexStats = mock(IndexStats.class);
         when(indexStats.getPrimaries()).thenReturn(primariesCommonStats);