Add deprecated API for creating History Ops Snapshot from translog

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

@@ -742,6 +742,19 @@ public abstract Translog.Snapshot newChangesSnapshot(
         boolean accurateCount
     ) throws IOException;
 
+    /**
+     * Reads history operations from the translog file instead of the lucene index
+     *
+     * @deprecated reading history operations from the translog file is deprecated and will be removed in the next release
+     */
+    @Deprecated
+    public abstract Translog.Snapshot newChangesSnapshotFromTranslogFile(
+        String source,
+        long fromSeqNo,
+        long toSeqNo,
+        boolean requiredFullRange
+    ) throws IOException;
+
     /**
      * Counts the number of history operations in the given sequence number range
      * @param source       source of the request

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

@@ -2821,6 +2821,20 @@ public Translog.Snapshot newChangesSnapshot(
         }
     }
 
+    /**
+     * Creates a new history snapshot from the translog file instead of the lucene index
+     *
+     * @deprecated reading history operations from the translog file is deprecated and will be removed in the next release
+     *
+     * Use {@link Engine#newChangesSnapshot(String, long, long, boolean, boolean)} instead
+     */
+    @Deprecated
+    @Override
+    public Translog.Snapshot newChangesSnapshotFromTranslogFile(String source, long fromSeqNo, long toSeqNo, boolean requiredFullRange)
+        throws IOException {
+        return getTranslog().newSnapshot(fromSeqNo, toSeqNo, requiredFullRange);
+    }
+
     public int countNumberOfHistoryOperations(String source, long fromSeqNo, long toSeqNo) throws IOException {
         ensureOpen();
         refreshIfNeeded(source, toSeqNo);

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

@@ -335,6 +335,20 @@ public Translog.Snapshot newChangesSnapshot(
         return newEmptySnapshot();
     }
 
+    /**
+     * Creates a new history snapshot from the translog file instead of the lucene index
+     *
+     * @deprecated reading history operations from the translog file is deprecated and will be removed in the next release
+     *
+     * Use {@link Engine#newChangesSnapshot(String, long, long, boolean, boolean)} instead
+     */
+    @Deprecated
+    @Override
+    public Translog.Snapshot newChangesSnapshotFromTranslogFile(String source, long fromSeqNo, long toSeqNo, boolean requiredFullRange)
+        throws IOException {
+        return newEmptySnapshot();
+    }
+
     @Override
     public int countNumberOfHistoryOperations(String source, long fromSeqNo, long toSeqNo) throws IOException {
         try (Translog.Snapshot snapshot = newChangesSnapshot(source, fromSeqNo, toSeqNo, false, true)) {

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

@@ -2233,13 +2233,25 @@ public Closeable acquireHistoryRetentionLock() {
     /**
      * Creates a new history snapshot for reading operations since
      * the provided starting seqno (inclusive) and ending seqno (inclusive)
-     * The returned snapshot can be retrieved from either Lucene index or translog files.
+     * The returned snapshot is retrieved from a Lucene index.
      */
     public Translog.Snapshot getHistoryOperations(String reason, long startingSeqNo, long endSeqNo, boolean accurateCount)
         throws IOException {
         return getEngine().newChangesSnapshot(reason, startingSeqNo, endSeqNo, true, accurateCount);
     }
 
+    /**
+     * Creates a new history snapshot from the translog file instead of the lucene index
+     *
+     * @deprecated reading history operations from the translog file is deprecated and will be removed in the next release
+     *
+     * Use {@link IndexShard#getHistoryOperations(String, long, long, boolean)} instead
+     */
+    @Deprecated
+    public Translog.Snapshot getHistoryOperationsFromTranslogFile(String reason, long startingSeqNo, long endSeqNo) throws IOException {
+        return getEngine().newChangesSnapshotFromTranslogFile(reason, startingSeqNo, endSeqNo, true);
+    }
+
     /**
      * Checks if we have a completed history of operations since the given starting seqno (inclusive).
      * This method should be called after acquiring the retention lock; See {@link #acquireHistoryRetentionLock()}

server/src/test/java/org/opensearch/index/engine/InternalEngineTests.java

@@ -6318,10 +6318,30 @@ public void testHistoryBasedOnSource() throws Exception {
                 }
             }
             List<Translog.Operation> luceneOps = readAllOperationsBasedOnSource(engine);
+            // todo remove in next release
+            List<Translog.Operation> translogOps = readAllOperationsBasedOnTranslog(engine);
             assertThat(luceneOps.stream().map(o -> o.seqNo()).collect(Collectors.toList()), containsInAnyOrder(expectedSeqNos.toArray()));
+            assertThat(translogOps.stream().map(o -> o.seqNo()).collect(Collectors.toList()), containsInAnyOrder(expectedSeqNos.toArray()));
         }
     }
 
+    /**
+     * Test creating new snapshot from translog file
+     *
+     * @deprecated reading history operations from the translog file is deprecated and will be removed in the next release
+     */
+    @Deprecated
+    private static List<Translog.Operation> readAllOperationsBasedOnTranslog(Engine engine) throws IOException {
+        final List<Translog.Operation> operations = new ArrayList<>();
+        try (Translog.Snapshot snapshot = engine.newChangesSnapshotFromTranslogFile("test", 0, Long.MAX_VALUE, false)) {
+            Translog.Operation op;
+            while ((op = snapshot.next()) != null) {
+                operations.add(op);
+            }
+        }
+        return operations;
+    }
+
     public void testLuceneHistoryOnPrimary() throws Exception {
         final List<Engine.Operation> operations = generateSingleDocHistory(
             false,