Github user yuruiz commented on a diff in the pull request:
https://github.com/apache/flink/pull/6075#discussion_r201630927
--- Diff:
flink-connectors/flink-orc/src/main/java/org/apache/flink/orc/OrcFileWriter.java
---
@@ -0,0 +1,269 @@
+/**
+ * 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
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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.flink.orc;
+
+import org.apache.flink.api.common.typeinfo.TypeInformation;
+import org.apache.flink.streaming.connectors.fs.StreamWriterBase;
+import org.apache.flink.streaming.connectors.fs.Writer;
+import org.apache.flink.table.api.TableSchema;
+import org.apache.flink.types.Row;
+
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hive.ql.exec.vector.BytesColumnVector;
+import org.apache.hadoop.hive.ql.exec.vector.DoubleColumnVector;
+import org.apache.hadoop.hive.ql.exec.vector.LongColumnVector;
+import org.apache.hadoop.hive.ql.exec.vector.VectorizedRowBatch;
+import org.apache.orc.CompressionKind;
+import org.apache.orc.OrcFile;
+import org.apache.orc.TypeDescription;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Objects;
+import java.util.stream.IntStream;
+
+import static org.apache.flink.orc.OrcBatchReader.schemaToTypeInfo;
+
+/**
+ * A {@link Writer} that writes the bucket files as Hadoop {@link OrcFile}.
+ *
+ * @param <T> The type of the elements that are being written by the sink.
+ */
+public class OrcFileWriter<T extends Row> extends StreamWriterBase<T> {
+
+ private static final long serialVersionUID = 3L;
+
+ /**
+ * The description of the types in an ORC file.
+ */
+ private TypeDescription schema;
+
+ /**
+ * The schema of an ORC file.
+ */
+ private String metaSchema;
+
+ /**
+ * A row batch that will be written to the ORC file.
+ */
+ private VectorizedRowBatch rowBatch;
+
+ /**
+ * The writer that fill the records into the batch.
+ */
+ private OrcBatchWriter orcBatchWriter;
+
+ private transient org.apache.orc.Writer writer;
+
+ private CompressionKind compressionKind;
+
+ /**
+ * The number of rows that currently being written.
+ */
+ private long writedRowSize;
+
+ /**
+ * Creates a new {@code OrcFileWriter} that writes orc files without
compression.
+ *
+ * @param metaSchema The orc schema.
+ */
+ public OrcFileWriter(String metaSchema) {
+ this(metaSchema, CompressionKind.NONE);
+ }
+
+ /**
+ * Create a new {@code OrcFileWriter} that writes orc file with the
gaven
+ * schema and compression kind.
+ *
+ * @param metaSchema The schema of an orc file.
+ * @param compressionKind The compression kind to use.
+ */
+ public OrcFileWriter(String metaSchema, CompressionKind
compressionKind) {
+ this.metaSchema = metaSchema;
+ this.schema = TypeDescription.fromString(metaSchema);
+ this.compressionKind = compressionKind;
+ }
+
+ @Override
+ public void open(FileSystem fs, Path path) throws IOException {
+ writer = OrcFile.createWriter(path,
OrcFile.writerOptions(fs.getConf()).setSchema(schema).compress(compressionKind));
+ rowBatch = schema.createRowBatch();
+ orcBatchWriter = new
OrcBatchWriter(Arrays.asList(orcSchemaToTableSchema(schema).getTypes()));
+ }
+
+ private TableSchema orcSchemaToTableSchema(TypeDescription orcSchema) {
+ List<String> fieldNames = orcSchema.getFieldNames();
+ List<TypeDescription> typeDescriptions =
orcSchema.getChildren();
+ List<TypeInformation> typeInformations = new ArrayList<>();
+
+ typeDescriptions.forEach(typeDescription -> {
+ typeInformations.add(schemaToTypeInfo(typeDescription));
+ });
+
+ return new TableSchema(
+ fieldNames.toArray(new String[fieldNames.size()]),
+ typeInformations.toArray(new
TypeInformation[typeInformations.size()]));
+ }
+
+ @Override
+ public void write(T element) throws IOException {
+ Boolean isFill = orcBatchWriter.fill(rowBatch, element);
+ if (!isFill) {
+ writer.addRowBatch(rowBatch);
+ writedRowSize += writedRowSize + rowBatch.size;
+ rowBatch.reset();
+ }
+ }
+
+ @Override
+ public long flush() throws IOException {
+ writer.addRowBatch(rowBatch);
--- End diff --
This call does not guarantee that the data would be persisted. The data
might still stay in memory and getting lost in case of fail over.
Another problem is that even the data is getting persisted, this orc file
might be unreadable since there is no proper File footer there. The correct
flushing behaviour should make sure that the data has been persisted and a
proper file footer has been created.
---
