diff --git a/extensions/barrage/src/main/java/io/deephaven/extensions/barrage/BarrageStreamGeneratorImpl.java b/extensions/barrage/src/main/java/io/deephaven/extensions/barrage/BarrageStreamGeneratorImpl.java
index 42c5889e3d3..3ce7d14fc9d 100644
--- a/extensions/barrage/src/main/java/io/deephaven/extensions/barrage/BarrageStreamGeneratorImpl.java
+++ b/extensions/barrage/src/main/java/io/deephaven/extensions/barrage/BarrageStreamGeneratorImpl.java
@@ -1191,88 +1191,6 @@ public RowSetShiftDataGenerator(final RowSetShiftData shifted) throws IOExceptio
         }
     }
 
-    public static class DrainableByteArrayInputStream extends DefensiveDrainable {
-
-        private byte[] buf;
-        private final int offset;
-        private final int length;
-
-        public DrainableByteArrayInputStream(final byte[] buf, final int offset, final int length) {
-            this.buf = Objects.requireNonNull(buf);
-            this.offset = offset;
-            this.length = length;
-        }
-
-        @Override
-        public int available() {
-            if (buf == null) {
-                return 0;
-            }
-            return length;
-        }
-
-        @Override
-        public int drainTo(final OutputStream outputStream) throws IOException {
-            if (buf != null) {
-                try {
-                    outputStream.write(buf, offset, length);
-                } finally {
-                    buf = null;
-                }
-                return length;
-            }
-            return 0;
-        }
-    }
-
-    public static class ConsecutiveDrainableStreams extends DefensiveDrainable {
-        final DefensiveDrainable[] streams;
-
-        public ConsecutiveDrainableStreams(final @NotNull DefensiveDrainable... streams) {
-            this.streams = streams;
-        }
-
-        @Override
-        public int drainTo(final OutputStream outputStream) throws IOException {
-            int total = 0;
-            for (final DefensiveDrainable stream : streams) {
-                final int expected = total + stream.available();
-                total += ((Drainable) stream).drainTo(outputStream);
-                if (expected != total) {
-                    throw new IllegalStateException("drained message drained wrong number of bytes");
-                }
-                if (total < 0) {
-                    throw new IllegalStateException("drained message is too large; exceeds Integer.MAX_VALUE");
-                }
-            }
-            return total;
-        }
-
-        @Override
-        public int available() throws SizeException, IOException {
-            int total = 0;
-            for (final DefensiveDrainable stream : streams) {
-                total += stream.available();
-                if (total < 0) {
-                    throw new SizeException("drained message is too large; exceeds Integer.MAX_VALUE", total);
-                }
-            }
-            return total;
-        }
-
-        @Override
-        public void close() throws IOException {
-            for (final DefensiveDrainable stream : streams) {
-                try {
-                    stream.close();
-                } catch (final IOException e) {
-                    throw new UncheckedDeephavenException("unexpected IOException", e);
-                }
-            }
-            super.close();
-        }
-    }
-
     private static final class EmptyRowSetGenerator extends RowSetGenerator {
         public static final EmptyRowSetGenerator INSTANCE;
         static {
diff --git a/extensions/barrage/src/main/java/io/deephaven/extensions/barrage/ConsecutiveDrainableStreams.java b/extensions/barrage/src/main/java/io/deephaven/extensions/barrage/ConsecutiveDrainableStreams.java
new file mode 100644
index 00000000000..c507e14e0b4
--- /dev/null
+++ b/extensions/barrage/src/main/java/io/deephaven/extensions/barrage/ConsecutiveDrainableStreams.java
@@ -0,0 +1,61 @@
+//
+// Copyright (c) 2016-2024 Deephaven Data Labs and Patent Pending
+//
+package io.deephaven.extensions.barrage;
+
+import io.deephaven.UncheckedDeephavenException;
+import io.deephaven.extensions.barrage.util.DefensiveDrainable;
+import io.deephaven.util.datastructures.SizeException;
+import io.grpc.Drainable;
+import org.jetbrains.annotations.NotNull;
+
+import java.io.IOException;
+import java.io.OutputStream;
+
+public class ConsecutiveDrainableStreams extends DefensiveDrainable {
+    final DefensiveDrainable[] streams;
+
+    public ConsecutiveDrainableStreams(final @NotNull DefensiveDrainable... streams) {
+        this.streams = streams;
+    }
+
+    @Override
+    public int drainTo(final OutputStream outputStream) throws IOException {
+        int total = 0;
+        for (final DefensiveDrainable stream : streams) {
+            final int expected = total + stream.available();
+            total += ((Drainable) stream).drainTo(outputStream);
+            if (expected != total) {
+                throw new IllegalStateException("drained message drained wrong number of bytes");
+            }
+            if (total < 0) {
+                throw new IllegalStateException("drained message is too large; exceeds Integer.MAX_VALUE");
+            }
+        }
+        return total;
+    }
+
+    @Override
+    public int available() throws SizeException, IOException {
+        int total = 0;
+        for (final DefensiveDrainable stream : streams) {
+            total += stream.available();
+            if (total < 0) {
+                throw new SizeException("drained message is too large; exceeds Integer.MAX_VALUE", total);
+            }
+        }
+        return total;
+    }
+
+    @Override
+    public void close() throws IOException {
+        for (final DefensiveDrainable stream : streams) {
+            try {
+                stream.close();
+            } catch (final IOException e) {
+                throw new UncheckedDeephavenException("unexpected IOException", e);
+            }
+        }
+        super.close();
+    }
+}
diff --git a/extensions/barrage/src/main/java/io/deephaven/extensions/barrage/DrainableByteArrayInputStream.java b/extensions/barrage/src/main/java/io/deephaven/extensions/barrage/DrainableByteArrayInputStream.java
new file mode 100644
index 00000000000..f2b14a7dc44
--- /dev/null
+++ b/extensions/barrage/src/main/java/io/deephaven/extensions/barrage/DrainableByteArrayInputStream.java
@@ -0,0 +1,44 @@
+//
+// Copyright (c) 2016-2024 Deephaven Data Labs and Patent Pending
+//
+package io.deephaven.extensions.barrage;
+
+import io.deephaven.extensions.barrage.util.DefensiveDrainable;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.util.Objects;
+
+public class DrainableByteArrayInputStream extends DefensiveDrainable {
+
+    private byte[] buf;
+    private final int offset;
+    private final int length;
+
+    public DrainableByteArrayInputStream(final byte[] buf, final int offset, final int length) {
+        this.buf = Objects.requireNonNull(buf);
+        this.offset = offset;
+        this.length = length;
+    }
+
+    @Override
+    public int available() {
+        if (buf == null) {
+            return 0;
+        }
+        return length;
+    }
+
+    @Override
+    public int drainTo(final OutputStream outputStream) throws IOException {
+        if (buf != null) {
+            try {
+                outputStream.write(buf, offset, length);
+            } finally {
+                buf = null;
+            }
+            return length;
+        }
+        return 0;
+    }
+}
diff --git a/extensions/barrage/src/test/java/io/deephaven/extensions/barrage/BarrageStreamGeneratorTest.java b/extensions/barrage/src/test/java/io/deephaven/extensions/barrage/BarrageStreamGeneratorTest.java
index e6c59d7efb8..73be2b851af 100644
--- a/extensions/barrage/src/test/java/io/deephaven/extensions/barrage/BarrageStreamGeneratorTest.java
+++ b/extensions/barrage/src/test/java/io/deephaven/extensions/barrage/BarrageStreamGeneratorTest.java
@@ -14,8 +14,8 @@ public class BarrageStreamGeneratorTest {
     @Test
     public void testDrainableStreamIsEmptied() throws IOException {
         final int length = 512;
-        final BarrageStreamGeneratorImpl.DrainableByteArrayInputStream inputStream =
-                new BarrageStreamGeneratorImpl.DrainableByteArrayInputStream(new byte[length * 2], length / 2, length);
+        final DrainableByteArrayInputStream inputStream =
+                new DrainableByteArrayInputStream(new byte[length * 2], length / 2, length);
 
         int bytesRead = inputStream.drainTo(new NullOutputStream());
 
@@ -26,12 +26,11 @@ public void testDrainableStreamIsEmptied() throws IOException {
     @Test
     public void testConsecutiveDrainableStreamIsEmptied() throws IOException {
         final int length = 512;
-        final BarrageStreamGeneratorImpl.DrainableByteArrayInputStream in1 =
-                new BarrageStreamGeneratorImpl.DrainableByteArrayInputStream(new byte[length * 2], length / 2, length);
-        final BarrageStreamGeneratorImpl.DrainableByteArrayInputStream in2 =
-                new BarrageStreamGeneratorImpl.DrainableByteArrayInputStream(new byte[length * 2], length / 2, length);
-        final BarrageStreamGeneratorImpl.ConsecutiveDrainableStreams inputStream =
-                new BarrageStreamGeneratorImpl.ConsecutiveDrainableStreams(in1, in2);
+        final DrainableByteArrayInputStream in1 =
+                new DrainableByteArrayInputStream(new byte[length * 2], length / 2, length);
+        final DrainableByteArrayInputStream in2 =
+                new DrainableByteArrayInputStream(new byte[length * 2], length / 2, length);
+        final ConsecutiveDrainableStreams inputStream = new ConsecutiveDrainableStreams(in1, in2);
 
         int bytesRead = inputStream.drainTo(new NullOutputStream());