Refactor RefreshStats 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 RefreshStats class to use the Builder pattern instead of constructors ([#19835](https://github.com/opensearch-project/OpenSearch/pull/19835))
 
 ### 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 RefreshStats in favor of the new Builder ([#19835](https://github.com/opensearch-project/OpenSearch/pull/19835))
 
 ### Removed
 

server/src/main/java/org/opensearch/index/refresh/RefreshStats.java

@@ -83,6 +83,11 @@ public void writeTo(StreamOutput out) throws IOException {
         out.writeVInt(listeners);
     }
 
+    /**
+     * This constructor will be deprecated starting in version 3.4.0.
+     * Use {@link Builder} instead.
+     */
+    @Deprecated
     public RefreshStats(long total, long totalTimeInMillis, long externalTotal, long externalTotalTimeInMillis, int listeners) {
         this.total = total;
         this.totalTimeInMillis = totalTimeInMillis;
@@ -167,6 +172,66 @@ public XContentBuilder toXContent(XContentBuilder builder, Params params) throws
         return builder;
     }
 
+    /**
+     * Private constructor that takes a builder.
+     * This is the sole entry point for creating a new RefreshStats object.
+     * @param builder The builder instance containing all the values.
+     */
+    private RefreshStats(Builder builder) {
+        this.total = builder.total;
+        this.totalTimeInMillis = builder.totalTimeInMillis;
+        this.externalTotal = builder.externalTotal;
+        this.externalTotalTimeInMillis = builder.externalTotalTimeInMillis;
+        this.listeners = builder.listeners;
+    }
+
+    /**
+     * Builder for the {@link RefreshStats} class.
+     * Provides a fluent API for constructing instances.
+     */
+    public static class Builder {
+        private long total = 0;
+        private long totalTimeInMillis = 0;
+        private long externalTotal = 0;
+        private long externalTotalTimeInMillis = 0;
+        private int listeners = 0;
+
+        public Builder() {}
+
+        public Builder total(long total) {
+            this.total = total;
+            return this;
+        }
+
+        public Builder totalTimeInMillis(long time) {
+            this.totalTimeInMillis = time;
+            return this;
+        }
+
+        public Builder externalTotal(long total) {
+            this.externalTotal = total;
+            return this;
+        }
+
+        public Builder externalTotalTimeInMillis(long time) {
+            this.externalTotalTimeInMillis = time;
+            return this;
+        }
+
+        public Builder listeners(int listeners) {
+            this.listeners = listeners;
+            return this;
+        }
+
+        /**
+         * Creates a {@link RefreshStats} object from the builder's current state.
+         * @return A new RefreshStats instance.
+         */
+        public RefreshStats build() {
+            return new RefreshStats(this);
+        }
+    }
+
     @Override
     public boolean equals(Object obj) {
         if (obj == null || obj.getClass() != RefreshStats.class) {

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

@@ -1503,13 +1503,12 @@ public long getWritingBytes() {
 
     public RefreshStats refreshStats() {
         int listeners = refreshListeners.pendingCount();
-        return new RefreshStats(
-            refreshMetric.count(),
-            TimeUnit.NANOSECONDS.toMillis(refreshMetric.sum()),
-            externalRefreshMetric.count(),
-            TimeUnit.NANOSECONDS.toMillis(externalRefreshMetric.sum()),
-            listeners
-        );
+        return new RefreshStats.Builder().total(refreshMetric.count())
+            .totalTimeInMillis(TimeUnit.NANOSECONDS.toMillis(refreshMetric.sum()))
+            .externalTotal(externalRefreshMetric.count())
+            .externalTotalTimeInMillis(TimeUnit.NANOSECONDS.toMillis(externalRefreshMetric.sum()))
+            .listeners(listeners)
+            .build();
     }
 
     public FlushStats flushStats() {

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

@@ -209,7 +209,7 @@ public Stats(StreamInput in) throws IOException {
         }
 
         /**
-         * This constructor will be deprecated starting in version 3.3.0.
+         * This constructor will be deprecated starting in version 3.4.0.
          * Use {@link Builder} instead.
          */
         @Deprecated
@@ -243,7 +243,7 @@ public Stats(
         }
 
         /**
-         * This constructor will be deprecated starting in version 3.3.0.
+         * This constructor will be deprecated starting in version 3.4.0.
          * Use {@link Builder} instead.
          */
         @Deprecated

server/src/main/java/org/opensearch/threadpool/ThreadPool.java

@@ -541,7 +541,18 @@ public ThreadPoolStats stats() {
                 continue;
             }
             if (holder.info.type == ThreadPoolType.FORK_JOIN) {
-                stats.add(new ThreadPoolStats.Stats(name, 0, 0, 0, 0, 0, 0, -1, holder.info.getMax()));
+                stats.add(
+                    new ThreadPoolStats.Stats.Builder().name(name)
+                        .threads(0)
+                        .queue(0)
+                        .active(0)
+                        .rejected(0)
+                        .largest(0)
+                        .completed(0)
+                        .waitTimeNanos(-1)
+                        .parallelism(holder.info.getMax())
+                        .build()
+                );
                 continue;
             }
             int threads = -1;

server/src/main/java/org/opensearch/threadpool/ThreadPoolStats.java

@@ -91,7 +91,7 @@ private Stats(Builder builder) {
         }
 
         /**
-         * This constructor will be deprecated starting in version 3.3.0.
+         * This constructor will be deprecated starting in version 3.4.0.
          * Use {@link Builder} instead.
          */
         @Deprecated
@@ -107,6 +107,11 @@ public Stats(String name, int threads, int queue, int active, long rejected, int
             this.parallelism = -1;
         }
 
+        /**
+         * This constructor will be deprecated starting in version 3.4.0.
+         * Use {@link Builder} instead.
+         */
+        @Deprecated
         public Stats(
             String name,
             int threads,

server/src/test/java/org/opensearch/index/autoforcemerge/AutoForceMergeManagerTests.java

@@ -815,7 +815,18 @@ private ExecutorService setupForceMergeThreadPool(int threadCount) {
         when(threadPool.executor(ThreadPool.Names.FORCE_MERGE)).thenReturn(executorService);
 
         ThreadPoolStats stats = new ThreadPoolStats(
-            Arrays.asList(new ThreadPoolStats.Stats(ThreadPool.Names.FORCE_MERGE, threadCount, 0, 0, 0, threadCount, 0, -1, -1))
+            Arrays.asList(
+                new ThreadPoolStats.Stats.Builder().name(ThreadPool.Names.FORCE_MERGE)
+                    .threads(threadCount)
+                    .queue(0)
+                    .active(0)
+                    .rejected(0)
+                    .largest(threadCount)
+                    .completed(0)
+                    .waitTimeNanos(-1)
+                    .parallelism(-1)
+                    .build()
+            )
         );
         when(threadPool.stats()).thenReturn(stats);
 

server/src/test/java/org/opensearch/index/refresh/RefreshStatsTests.java

@@ -41,13 +41,13 @@
 public class RefreshStatsTests extends OpenSearchTestCase {
 
     public void testSerialize() throws IOException {
-        RefreshStats stats = new RefreshStats(
-            randomNonNegativeLong(),
-            randomNonNegativeLong(),
-            randomNonNegativeLong(),
-            randomNonNegativeLong(),
-            between(0, Integer.MAX_VALUE)
-        );
+        RefreshStats stats = new RefreshStats.Builder().total(randomNonNegativeLong())
+            .totalTimeInMillis(randomNonNegativeLong())
+            .externalTotal(randomNonNegativeLong())
+            .externalTotalTimeInMillis(randomNonNegativeLong())
+            .listeners(between(0, Integer.MAX_VALUE))
+            .build();
+
         BytesStreamOutput out = new BytesStreamOutput();
         stats.writeTo(out);
         StreamInput input = out.bytes().streamInput();

server/src/test/java/org/opensearch/rest/action/cat/RestThreadPoolActionRowTests.java

@@ -56,7 +56,16 @@ public void testForkJoinRow() {
         final int parallelism = 7;
 
         ThreadPool.Info fjInfo = new ThreadPool.Info(poolName, ThreadPool.ThreadPoolType.FORK_JOIN, parallelism, parallelism, null, null);
-        ThreadPoolStats.Stats dummyStats = new ThreadPoolStats.Stats(poolName, 0, 0, 0, 0, 0, 0, -1, parallelism);
+        ThreadPoolStats.Stats dummyStats = new ThreadPoolStats.Stats.Builder().name(poolName)
+            .threads(0)
+            .queue(0)
+            .active(0)
+            .rejected(0)
+            .largest(0)
+            .completed(0)
+            .waitTimeNanos(-1)
+            .parallelism(parallelism)
+            .build();
 
         Table table = action.getTableWithHeader(new FakeRestRequest.Builder(xContentRegistry()).build());
         action.writeRow(table, nodeName, nodeId, eid, pid, host, ip, port, poolName, fjInfo, dummyStats);
@@ -93,7 +102,16 @@ public void testNonForkJoinRowScaling() {
         final String poolName = "generic";
 
         ThreadPool.Info scalingInfo = new ThreadPool.Info(poolName, ThreadPool.ThreadPoolType.SCALING, 1, 4, null, null);
-        ThreadPoolStats.Stats stats = new ThreadPoolStats.Stats(poolName, 3, 2, 1, 5L, 3, 10L, 111L, -1);
+        ThreadPoolStats.Stats stats = new ThreadPoolStats.Stats.Builder().name(poolName)
+            .threads(3)
+            .queue(2)
+            .active(1)
+            .rejected(5L)
+            .largest(3)
+            .completed(10L)
+            .waitTimeNanos(111L)
+            .parallelism(-1)
+            .build();
 
         Table table = action.getTableWithHeader(new FakeRestRequest.Builder(xContentRegistry()).build());
         action.writeRow(table, nodeName, nodeId, eid, pid, host, ip, port, poolName, scalingInfo, stats);
@@ -120,7 +138,17 @@ public void testForkJoinRowParallelismZero() {
         final String poolName = "fj_zero";
         final int parallelism = 0;
         ThreadPool.Info fjInfo = new ThreadPool.Info(poolName, ThreadPool.ThreadPoolType.FORK_JOIN, parallelism, parallelism, null, null);
-        ThreadPoolStats.Stats dummyStats = new ThreadPoolStats.Stats(poolName, 0, 0, 0, 0, 0, 0, -1, parallelism);
+        ThreadPoolStats.Stats dummyStats = new ThreadPoolStats.Stats.Builder().name(poolName)
+            .threads(0)
+            .queue(0)
+            .active(0)
+            .rejected(0)
+            .largest(0)
+            .completed(0)
+            .waitTimeNanos(-1)
+            .parallelism(parallelism)
+            .build();
+
         Table table = action.getTableWithHeader(new FakeRestRequest.Builder(xContentRegistry()).build());
         action.writeRow(table, "n", "id", "eid", 1L, "h", "ip", 9300, poolName, fjInfo, dummyStats);
         assertEquals(parallelism, table.getRows().get(0).get(indexOf(table).get("parallelism")).value);
@@ -130,7 +158,16 @@ public void testForkJoinRowParallelismNegative() {
         final String poolName = "fj_negative";
         final int parallelism = -5;
         ThreadPool.Info fjInfo = new ThreadPool.Info(poolName, ThreadPool.ThreadPoolType.FORK_JOIN, parallelism, parallelism, null, null);
-        ThreadPoolStats.Stats dummyStats = new ThreadPoolStats.Stats(poolName, 0, 0, 0, 0, 0, 0, -1, parallelism);
+        ThreadPoolStats.Stats dummyStats = new ThreadPoolStats.Stats.Builder().name(poolName)
+            .threads(0)
+            .queue(0)
+            .active(0)
+            .rejected(0)
+            .largest(0)
+            .completed(0)
+            .waitTimeNanos(-1)
+            .parallelism(parallelism)
+            .build();
 
         Table table = action.getTableWithHeader(new FakeRestRequest.Builder(xContentRegistry()).build());
         action.writeRow(table, "n", "id", "eid", 1L, "h", "ip", 9300, poolName, fjInfo, dummyStats);
@@ -141,7 +178,16 @@ public void testForkJoinRowNullInfo() {
         final String poolName = "fj_nullinfo";
         final int parallelism = 3;
         ThreadPool.Info fjInfo = null; // null info
-        ThreadPoolStats.Stats dummyStats = new ThreadPoolStats.Stats(poolName, 0, 0, 0, 0, 0, 0, -1, parallelism);
+        ThreadPoolStats.Stats dummyStats = new ThreadPoolStats.Stats.Builder().name(poolName)
+            .threads(0)
+            .queue(0)
+            .active(0)
+            .rejected(0)
+            .largest(0)
+            .completed(0)
+            .waitTimeNanos(-1)
+            .parallelism(parallelism)
+            .build();
 
         Table table = action.getTableWithHeader(new FakeRestRequest.Builder(xContentRegistry()).build());
         action.writeRow(table, "n", "id", "eid", 1L, "h", "ip", 9300, poolName, fjInfo, dummyStats);
@@ -177,7 +223,16 @@ public void testMultipleForkJoinRows() {
                 null,
                 null
             );
-            ThreadPoolStats.Stats dummyStats = new ThreadPoolStats.Stats(poolNames[i], 0, 0, 0, 0, 0, 0, -1, parallelisms[i]);
+            ThreadPoolStats.Stats dummyStats = new ThreadPoolStats.Stats.Builder().name(poolNames[i])
+                .threads(0)
+                .queue(0)
+                .active(0)
+                .rejected(0)
+                .largest(0)
+                .completed(0)
+                .waitTimeNanos(-1)
+                .parallelism(parallelisms[i])
+                .build();
             action.writeRow(table, "n" + i, "id" + i, "eid" + i, 1L, "h" + i, "ip" + i, 9300 + i, poolNames[i], fjInfo, dummyStats);
         }
         assertEquals(2, table.getRows().size());
@@ -190,7 +245,16 @@ public void testForkJoinRowLargeParallelism() {
         final String poolName = "fj_large";
         final int parallelism = Integer.MAX_VALUE;
         ThreadPool.Info fjInfo = new ThreadPool.Info(poolName, ThreadPool.ThreadPoolType.FORK_JOIN, parallelism, parallelism, null, null);
-        ThreadPoolStats.Stats dummyStats = new ThreadPoolStats.Stats(poolName, 0, 0, 0, 0, 0, 0, -1, parallelism);
+        ThreadPoolStats.Stats dummyStats = new ThreadPoolStats.Stats.Builder().name(poolName)
+            .threads(0)
+            .queue(0)
+            .active(0)
+            .rejected(0)
+            .largest(0)
+            .completed(0)
+            .waitTimeNanos(-1)
+            .parallelism(parallelism)
+            .build();
 
         Table table = action.getTableWithHeader(new FakeRestRequest.Builder(xContentRegistry()).build());
         action.writeRow(table, "n", "id", "eid", 1L, "h", "ip", 9300, poolName, fjInfo, dummyStats);
@@ -322,7 +386,16 @@ public void testBuildTableWithForkJoinPool() throws Exception {
         when(nodesInfoResponse.getNodesMap()).thenReturn(nodeInfoMap);
 
         // 5. ThreadPoolStats.Stats for ForkJoin
-        ThreadPoolStats.Stats fjStats = new ThreadPoolStats.Stats(poolName, 0, 0, 0, 0, 0, 0, -1, parallelism);
+        ThreadPoolStats.Stats fjStats = new ThreadPoolStats.Stats.Builder().name(poolName)
+            .threads(0)
+            .queue(0)
+            .active(0)
+            .rejected(0)
+            .largest(0)
+            .completed(0)
+            .waitTimeNanos(-1)
+            .parallelism(parallelism)
+            .build();
         ThreadPoolStats threadPoolStats = new ThreadPoolStats(new ArrayList<>(List.of(fjStats)));
         NodeStats nodeStats = mock(NodeStats.class);
         when(nodeStats.getThreadPool()).thenReturn(threadPoolStats);

server/src/test/java/org/opensearch/rest/action/cat/RestThreadPoolActionTests.java

@@ -26,17 +26,16 @@ public class RestThreadPoolActionTests extends OpenSearchTestCase {
 
     public void testForkJoinPoolTypeStatsAreReported() {
         // Setup for ForkJoinPool stats
-        ThreadPoolStats.Stats fjStats = new ThreadPoolStats.Stats(
-            "fork_join", // name
-            42,          // active
-            84,          // rejected
-            21,          // largest
-            64,          // completed
-            -1,          // queue (should be -1 for FJ)
-            1,           // threads
-            0,           // taskTimeNanos (or whatever the last arg is)
-            8            // parallelism (for example: 8, or whatever is appropriate for your test)
-        );
+        ThreadPoolStats.Stats fjStats = new ThreadPoolStats.Stats.Builder().name("fork_join")
+            .threads(1)
+            .queue(-1) // should be -1 for FJ
+            .active(42)
+            .rejected(84)
+            .largest(21)
+            .completed(64)
+            .waitTimeNanos(0) // or whatever the last arg is
+            .parallelism(8) // for example: 8, or whatever is appropriate for your test
+            .build();
 
         List<ThreadPoolStats.Stats> statsList = Collections.singletonList(fjStats);