XuQianJin-Stars commented on code in PR #2345: URL: https://github.com/apache/fluss/pull/2345#discussion_r2697178534
########## fluss-lake/fluss-lake-lance/src/main/java/org/apache/fluss/lake/lance/utils/ArrowDataConverter.java: ########## @@ -0,0 +1,141 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.fluss.lake.lance.utils; + +import org.apache.arrow.memory.ArrowBuf; +import org.apache.arrow.memory.BufferAllocator; +import org.apache.arrow.vector.FieldVector; +import org.apache.arrow.vector.VectorSchemaRoot; +import org.apache.arrow.vector.types.pojo.Schema; + +import java.lang.reflect.Field; +import java.lang.reflect.Method; +import java.nio.ByteBuffer; +import java.util.List; + +/** + * Utility class to convert between shaded and non-shaded Arrow VectorSchemaRoot by sharing off-heap + * memory directly. + * + * <p>Since both shaded and non-shaded Arrow use the same off-heap memory layout, we can share the + * underlying ByteBuffer/memory address directly without serialization overhead. + */ +public class ArrowDataConverter { + + /** + * Converts a shaded Arrow VectorSchemaRoot to a non-shaded Arrow VectorSchemaRoot by sharing + * the underlying off-heap memory. + * + * @param shadedRoot The shaded Arrow VectorSchemaRoot from fluss-common + * @param nonShadedAllocator The non-shaded BufferAllocator for Lance + * @param nonShadedSchema The non-shaded Arrow Schema for Lance + * @return A non-shaded VectorSchemaRoot compatible with Lance + */ + public static VectorSchemaRoot convertToNonShaded( + org.apache.fluss.shaded.arrow.org.apache.arrow.vector.VectorSchemaRoot shadedRoot, + BufferAllocator nonShadedAllocator, + Schema nonShadedSchema) { + + VectorSchemaRoot nonShadedRoot = + VectorSchemaRoot.create(nonShadedSchema, nonShadedAllocator); + nonShadedRoot.allocateNew(); + + List<org.apache.fluss.shaded.arrow.org.apache.arrow.vector.FieldVector> shadedVectors = + shadedRoot.getFieldVectors(); + List<FieldVector> nonShadedVectors = nonShadedRoot.getFieldVectors(); + + for (int i = 0; i < shadedVectors.size(); i++) { + copyVectorData(shadedVectors.get(i), nonShadedVectors.get(i)); + } + + nonShadedRoot.setRowCount(shadedRoot.getRowCount()); + return nonShadedRoot; + } + + private static void copyVectorData( + org.apache.fluss.shaded.arrow.org.apache.arrow.vector.FieldVector shadedVector, + FieldVector nonShadedVector) { + try { + List<org.apache.fluss.shaded.arrow.org.apache.arrow.memory.ArrowBuf> shadedBuffers = + getFieldBuffers(shadedVector); + + int valueCount = getValueCount(shadedVector); + nonShadedVector.setValueCount(valueCount); + + List<ArrowBuf> nonShadedBuffers = nonShadedVector.getFieldBuffers(); + + for (int i = 0; i < Math.min(shadedBuffers.size(), nonShadedBuffers.size()); i++) { + org.apache.fluss.shaded.arrow.org.apache.arrow.memory.ArrowBuf shadedBuf = + shadedBuffers.get(i); + ArrowBuf nonShadedBuf = nonShadedBuffers.get(i); + + long size = Math.min(shadedBuf.capacity(), nonShadedBuf.capacity()); + if (size > 0) { + ByteBuffer srcBuffer = getByteBuffer(shadedBuf); + if (srcBuffer != null) { + srcBuffer.position(0); + srcBuffer.limit((int) Math.min(size, Integer.MAX_VALUE)); + nonShadedBuf.setBytes(0, srcBuffer); + } + } + } + } catch (Exception e) { + throw new RuntimeException("Failed to copy vector data via off-heap memory", e); + } + } + + @SuppressWarnings("unchecked") + private static List<org.apache.fluss.shaded.arrow.org.apache.arrow.memory.ArrowBuf> + getFieldBuffers( + org.apache.fluss.shaded.arrow.org.apache.arrow.vector.FieldVector vector) { + try { + Method method = vector.getClass().getMethod("getFieldBuffers"); + return (List<org.apache.fluss.shaded.arrow.org.apache.arrow.memory.ArrowBuf>) + method.invoke(vector); + } catch (Exception e) { + throw new RuntimeException("Failed to get field buffers from shaded vector", e); + } + } + + private static int getValueCount( + org.apache.fluss.shaded.arrow.org.apache.arrow.vector.FieldVector vector) { + try { + Method method = vector.getClass().getMethod("getValueCount"); + return (int) method.invoke(vector); + } catch (Exception e) { + throw new RuntimeException("Failed to get value count from shaded vector", e); + } + } + + private static ByteBuffer getByteBuffer( + org.apache.fluss.shaded.arrow.org.apache.arrow.memory.ArrowBuf buf) { + try { + Method method = buf.getClass().getMethod("nioBuffer", long.class, int.class); + return (ByteBuffer) method.invoke(buf, 0L, (int) buf.capacity()); + } catch (Exception e) { + try { + Field field = buf.getClass().getDeclaredField("memoryAddress"); + field.setAccessible(true); + long address = (long) field.get(buf); + return null; + } catch (Exception ex) { + throw new RuntimeException("Failed to get ByteBuffer from ArrowBuf", ex); Review Comment: > Why introduce these reflections? It seems they provide these methods and can be directly invoked. <img width="1890" height="1004" alt="Clipboard_Screenshot_1768544374" src="https://github.com/user-attachments/assets/cfcfd40d-1a9b-47ad-a528-d01c4abd9b06"; /> <img width="1846" height="750" alt="Clipboard_Screenshot_1768544419" src="https://github.com/user-attachments/assets/cc7488ac-7a21-438c-aa5c-a2150b8fd51f"; /> Here, a `VectorSchemaRoot` constructed with non-shadowed arrows must be used. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
