JingsongLi commented on code in PR #8391: URL: https://github.com/apache/paimon/pull/8391#discussion_r3503156076
########## paimon-flink/paimon-flink-common/src/main/java/org/apache/paimon/flink/lookup/BlobAsDescriptorRow.java: ########## @@ -0,0 +1,215 @@ +/* + * 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.paimon.flink.lookup; + +import org.apache.paimon.data.BinaryString; +import org.apache.paimon.data.Blob; +import org.apache.paimon.data.Decimal; +import org.apache.paimon.data.InternalArray; +import org.apache.paimon.data.InternalMap; +import org.apache.paimon.data.InternalRow; +import org.apache.paimon.data.InternalVector; +import org.apache.paimon.data.Timestamp; +import org.apache.paimon.data.variant.Variant; +import org.apache.paimon.types.DataType; +import org.apache.paimon.types.DataTypeRoot; +import org.apache.paimon.types.RowKind; +import org.apache.paimon.types.RowType; +import org.apache.paimon.types.VarBinaryType; + +import java.util.ArrayList; +import java.util.HashSet; +import java.util.List; +import java.util.Set; + +/** + * An {@link InternalRow} wrapper that converts BLOB fields to their BlobDescriptor serialized + * bytes. + * + * <p>When the lookup cache stores blob descriptors instead of full blob data, this wrapper + * intercepts access to BLOB fields and returns the serialized BlobDescriptor bytes via {@link + * #getBinary(int)}. This allows the lookup cache to store only lightweight references (~100-150 + * bytes) instead of the full blob content (which can be megabytes per record). + * + * <p>Non-blob fields are delegated to the wrapped row unchanged. + */ +public class BlobAsDescriptorRow implements InternalRow { + + private final InternalRow wrapped; + private final Set<Integer> blobFieldPositions; + + public BlobAsDescriptorRow(InternalRow wrapped, Set<Integer> blobFieldPositions) { + this.wrapped = wrapped; + this.blobFieldPositions = blobFieldPositions; + } + + /** + * Returns the set of field positions that are BLOB type in the given row type. + * + * @param rowType the row type to inspect + * @return set of positions with BLOB type fields, empty if none + */ + public static Set<Integer> blobFieldPositions(RowType rowType) { + Set<Integer> positions = new HashSet<>(); + List<DataType> fieldTypes = rowType.getFieldTypes(); + for (int i = 0; i < fieldTypes.size(); i++) { + if (fieldTypes.get(i).getTypeRoot() == DataTypeRoot.BLOB) { + positions.add(i); + } + } + return positions; + } + + /** + * Creates a new RowType where BLOB fields are replaced with VARBINARY. This is used to create + * the correct serializer that uses BinarySerializer instead of BlobSerializer for cached + * values. + * + * @param rowType the original row type + * @param blobPositions the positions of BLOB fields + * @return a new RowType with BLOB fields replaced by VARBINARY + */ + public static RowType replaceBlobWithVarBinary(RowType rowType, Set<Integer> blobPositions) { + if (blobPositions.isEmpty()) { + return rowType; + } + List<DataType> newTypes = new ArrayList<>(rowType.getFieldTypes()); + for (int pos : blobPositions) { + newTypes.set(pos, new VarBinaryType(VarBinaryType.MAX_LENGTH)); + } + RowType.Builder builder = RowType.builder(); + for (int i = 0; i < rowType.getFieldCount(); i++) { + builder.field(rowType.getFields().get(i).name(), newTypes.get(i)); + } + return builder.build(); + } + + @Override + public int getFieldCount() { + return wrapped.getFieldCount(); + } + + @Override + public RowKind getRowKind() { + return wrapped.getRowKind(); + } + + @Override + public void setRowKind(RowKind kind) { + wrapped.setRowKind(kind); + } + + @Override + public boolean isNullAt(int pos) { + return wrapped.isNullAt(pos); + } + + @Override + public boolean getBoolean(int pos) { + return wrapped.getBoolean(pos); + } + + @Override + public byte getByte(int pos) { + return wrapped.getByte(pos); + } + + @Override + public short getShort(int pos) { + return wrapped.getShort(pos); + } + + @Override + public int getInt(int pos) { + return wrapped.getInt(pos); + } + + @Override + public long getLong(int pos) { + return wrapped.getLong(pos); + } + + @Override + public float getFloat(int pos) { + return wrapped.getFloat(pos); + } + + @Override + public double getDouble(int pos) { + return wrapped.getDouble(pos); + } + + @Override + public BinaryString getString(int pos) { + return wrapped.getString(pos); + } + + @Override + public Decimal getDecimal(int pos, int precision, int scale) { + return wrapped.getDecimal(pos, precision, scale); + } + + @Override + public Timestamp getTimestamp(int pos, int precision) { + return wrapped.getTimestamp(pos, precision); + } + + @Override + public byte[] getBinary(int pos) { + if (blobFieldPositions.contains(pos)) { + // Convert blob to descriptor bytes for caching + Blob blob = wrapped.getBlob(pos); + if (blob == null) { + return null; + } + return blob.toDescriptor().serialize(); Review Comment: This assumes the row entering the lookup cache already carries descriptor-backed BLOB values. The lookup reader still reads table data using the normal `blob-as-descriptor` option, while this new `lookup.blob-as-descriptor` option only changes the cache serializer/wrapper. For a normal BLOB table with `blob-as-descriptor=false`, `BlobFormatReader` returns `BlobData`; then this call to `blob.toDescriptor()` throws `Blob data can not convert to descriptor` during bootstrap/refresh. Could we either make the lookup reader read BLOB fields in descriptor mode when this option is enabled, or reject/document the unsupported combination before the cache starts loading? -- 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]
