[
https://issues.apache.org/jira/browse/BEAM-8933?focusedWorklogId=378554&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-378554
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ASF GitHub Bot logged work on BEAM-8933:
----------------------------------------
Author: ASF GitHub Bot
Created on: 28/Jan/20 23:05
Start Date: 28/Jan/20 23:05
Worklog Time Spent: 10m
Work Description: emkornfield commented on pull request #10384:
[BEAM-8933] Utilities for converting Arrow schemas and reading Arrow batches as
Rows
URL: https://github.com/apache/beam/pull/10384#discussion_r372108633
##########
File path:
sdks/java/extensions/arrow/src/main/java/org/apache/beam/sdk/extensions/arrow/ArrowConversion.java
##########
@@ -0,0 +1,448 @@
+/*
+ * 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.beam.sdk.extensions.arrow;
+
+import static
org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkArgument;
+
+import java.util.Iterator;
+import java.util.List;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+import javax.annotation.Nullable;
+import org.apache.arrow.vector.FieldVector;
+import org.apache.arrow.vector.VectorSchemaRoot;
+import org.apache.arrow.vector.types.TimeUnit;
+import org.apache.arrow.vector.types.pojo.ArrowType;
+import org.apache.arrow.vector.util.Text;
+import org.apache.beam.sdk.annotations.Experimental;
+import org.apache.beam.sdk.schemas.CachingFactory;
+import org.apache.beam.sdk.schemas.Factory;
+import org.apache.beam.sdk.schemas.FieldValueGetter;
+import org.apache.beam.sdk.schemas.Schema;
+import org.apache.beam.sdk.schemas.Schema.Field;
+import org.apache.beam.sdk.schemas.Schema.FieldType;
+import org.apache.beam.sdk.schemas.logicaltypes.FixedBytes;
+import org.apache.beam.sdk.values.Row;
+import org.joda.time.DateTime;
+import org.joda.time.DateTimeZone;
+
+/**
+ * Utilities to create {@link Iterable}s of Beam {@link Row} instances backed
by Arrow record
+ * batches.
+ */
+@Experimental(Experimental.Kind.SCHEMAS)
+public class ArrowConversion {
+ /** Converts Arrow schema to Beam row schema. */
+ public static Schema toBeamSchema(org.apache.arrow.vector.types.pojo.Schema
schema) {
+ return toBeamSchema(schema.getFields());
+ }
+
+ public static Schema
toBeamSchema(List<org.apache.arrow.vector.types.pojo.Field> fields) {
+ Schema.Builder builder = Schema.builder();
+ for (org.apache.arrow.vector.types.pojo.Field field : fields) {
+ Field beamField = toBeamField(field);
+ builder.addField(beamField);
+ }
+ return builder.build();
+ }
+
+ /** Get Beam Field from Arrow Field. */
+ private static Field toBeamField(org.apache.arrow.vector.types.pojo.Field
field) {
+ FieldType beamFieldType = toFieldType(field.getFieldType(),
field.getChildren());
+ return Field.of(field.getName(), beamFieldType);
+ }
+
+ /** Converts Arrow FieldType to Beam FieldType. */
+ private static FieldType toFieldType(
+ org.apache.arrow.vector.types.pojo.FieldType arrowFieldType,
+ List<org.apache.arrow.vector.types.pojo.Field> childrenFields) {
+ FieldType fieldType =
+ arrowFieldType
+ .getType()
+ .accept(
+ new ArrowType.ArrowTypeVisitor<FieldType>() {
+ @Override
+ public FieldType visit(ArrowType.Null type) {
+ throw new IllegalArgumentException(
+ "Type \'" + type.toString() + "\' not supported.");
+ }
+
+ @Override
+ public FieldType visit(ArrowType.Struct type) {
+ return FieldType.row(toBeamSchema(childrenFields));
+ }
+
+ @Override
+ public FieldType visit(ArrowType.List type) {
+ checkArgument(
+ childrenFields.size() == 1,
+ "Encountered "
+ + childrenFields.size()
+ + " child fields for list type, expected 1");
+ return
FieldType.array(toBeamField(childrenFields.get(0)).getType());
+ }
+
+ @Override
+ public FieldType visit(ArrowType.FixedSizeList type) {
+ throw new IllegalArgumentException(
+ "Type \'" + type.toString() + "\' not supported.");
+ }
+
+ @Override
+ public FieldType visit(ArrowType.Union type) {
+ throw new IllegalArgumentException(
+ "Type \'" + type.toString() + "\' not supported.");
+ }
+
+ @Override
+ public FieldType visit(ArrowType.Map type) {
+ checkArgument(
+ childrenFields.size() == 2,
+ "Encountered "
+ + childrenFields.size()
+ + " child fields for map type, expected 2");
+ return FieldType.map(
+ toBeamField(childrenFields.get(0)).getType(),
+ toBeamField(childrenFields.get(1)).getType());
+ }
+
+ @Override
+ public FieldType visit(ArrowType.Int type) {
+ if (!type.getIsSigned()) {
+ throw new IllegalArgumentException("Unsigned integers
are not supported.");
+ }
+ switch (type.getBitWidth()) {
+ case 8:
+ return FieldType.BYTE;
+ case 16:
+ return FieldType.INT16;
+ case 32:
+ return FieldType.INT32;
+ case 64:
+ return FieldType.INT64;
+ default:
+ throw new IllegalArgumentException(
+ "Unsupported integer bit width: " +
type.getBitWidth());
+ }
+ }
+
+ @Override
+ public FieldType visit(ArrowType.FloatingPoint type) {
+ switch (type.getPrecision()) {
+ case SINGLE:
+ return FieldType.FLOAT;
+ case DOUBLE:
+ return FieldType.DOUBLE;
+ default:
+ throw new IllegalArgumentException(
+ "Unsupported floating-point precision: " +
type.getPrecision().name());
+ }
+ }
+
+ @Override
+ public FieldType visit(ArrowType.Utf8 type) {
+ return FieldType.STRING;
+ }
+
+ @Override
+ public FieldType visit(ArrowType.Binary type) {
+ return FieldType.BYTES;
+ }
+
+ @Override
+ public FieldType visit(ArrowType.FixedSizeBinary type) {
+ return
FieldType.logicalType(FixedBytes.of(type.getByteWidth()));
+ }
+
+ @Override
+ public FieldType visit(ArrowType.Bool type) {
+ return FieldType.BOOLEAN;
+ }
+
+ @Override
+ public FieldType visit(ArrowType.Decimal type) {
+ // FieldType.DECIMAL isn't perfect here since arrow
decimal has a
+ // scale/precision fixed by the schema, but
FieldType.DECIMAL uses a BigDecimal,
+ // whose precision/scale can change from row to row.
+ throw new IllegalArgumentException(
+ "Type \'" + type.toString() + "\' not supported.");
+ }
+
+ @Override
+ public FieldType visit(ArrowType.Date type) {
+ throw new IllegalArgumentException(
+ "Type \'" + type.toString() + "\' not supported.");
+ }
+
+ @Override
+ public FieldType visit(ArrowType.Time type) {
+ throw new IllegalArgumentException(
+ "Type \'" + type.toString() + "\' not supported.");
+ }
+
+ @Override
+ public FieldType visit(ArrowType.Timestamp type) {
+ if (type.getUnit() == TimeUnit.MILLISECOND
+ || type.getUnit() == TimeUnit.MICROSECOND) {
+ return FieldType.DATETIME;
+ } else {
+ throw new IllegalArgumentException(
+ "Unsupported timestamp unit: " +
type.getUnit().name());
+ }
+ }
+
+ @Override
+ public FieldType visit(ArrowType.Interval type) {
+ throw new IllegalArgumentException(
+ "Type \'" + type.toString() + "\' not supported.");
+ }
+
+ @Override
+ public FieldType visit(ArrowType.Duration type) {
+ throw new IllegalArgumentException(
+ "Type \'" + type.toString() + "\' not supported.");
+ }
+ });
+ return fieldType.withNullable(arrowFieldType.isNullable());
+ }
+
+ /**
+ * Returns an {@link Iterable<Row>} backed by the Arrow record batch stored
in {@code
+ * vectorSchemaRoot}.
+ *
+ * <p>Note this is a lazy interface. The data in the underlying Arrow buffer
is not read until a
+ * field of one of the returned {@link Row}s is accessed.
+ */
+ public static Iterable<Row> rowsFromRecordBatch(
+ Schema schema, VectorSchemaRoot vectorSchemaRoot) {
+ return new RecordBatchIterable(schema, vectorSchemaRoot);
+ }
+
+ public static Iterable<Row> rowsFromRecordBatch(VectorSchemaRoot
vectorSchemaRoot) {
+ return rowsFromRecordBatch(toBeamSchema(vectorSchemaRoot.getSchema()),
vectorSchemaRoot);
+ }
+
+ private static class VectorSchemaRootRowIterator implements Iterator<Row> {
+ private static final ArrowValueConverterVisitor valueConverterVisitor =
+ new ArrowValueConverterVisitor();
+ private final Schema schema;
+ private final VectorSchemaRoot vectorSchemaRoot;
+ private final Factory<List<FieldValueGetter>> fieldValueGetters;
+ private Integer currRowIndex;
+
+ private static class FieldVectorListValueGetterFactory
+ implements Factory<List<FieldValueGetter>> {
+ private final List<FieldVector> fieldVectors;
+
+ static FieldVectorListValueGetterFactory of(List<FieldVector>
fieldVectors) {
+ return new FieldVectorListValueGetterFactory(fieldVectors);
+ }
+
+ private FieldVectorListValueGetterFactory(List<FieldVector>
fieldVectors) {
+ this.fieldVectors = fieldVectors;
+ }
+
+ @Override
+ public List<FieldValueGetter> create(Class<?> clazz, Schema schema) {
+ return this.fieldVectors.stream()
+ .map(
+ (fieldVector) -> {
+ Function<Object, Object> conversionFunction =
+
fieldVector.getField().getFieldType().getType().accept(valueConverterVisitor);
+ if (conversionFunction == null) {
+ return new FieldValueGetter<Integer, Object>() {
+ @Nullable
+ @Override
+ public Object get(Integer rowIndex) {
+ return fieldVector.getObject(rowIndex);
+ }
+
+ @Override
+ public String name() {
+ return fieldVector.getField().getName();
+ }
+ };
+ } else {
+ return new FieldValueGetter<Integer, Object>() {
+ @Nullable
+ @Override
+ public Object get(Integer rowIndex) {
+ Object value = fieldVector.getObject(rowIndex);
+ if (value == null) {
+ return null;
+ }
+
+ return conversionFunction.apply(value);
+ }
+
+ @Override
+ public String name() {
+ return fieldVector.getField().getName();
+ }
+ };
+ }
+ })
+ .collect(Collectors.toList());
+ }
+ }
+
+ // TODO: Consider using ByteBuddyUtils.TypeConversion for this
+ private static class ArrowValueConverterVisitor
+ implements ArrowType.ArrowTypeVisitor<Function<Object, Object>> {
+ @Override
+ public Function<Object, Object> visit(ArrowType.Null type) {
+ throw new IllegalArgumentException("Type \'" + type.toString() + "\'
not supported.");
+ }
+
+ @Override
+ public Function<Object, Object> visit(ArrowType.Struct type) {
+ // TODO: code to create a row.
+ return null;
+ }
+
+ @Override
+ public Function<Object, Object> visit(ArrowType.List type) {
+ return null;
+ }
+
+ @Override
+ public Function<Object, Object> visit(ArrowType.FixedSizeList type) {
+ throw new IllegalArgumentException("Type \'" + type.toString() + "\'
not supported.");
+ }
+
+ @Override
+ public Function<Object, Object> visit(ArrowType.Union type) {
+ throw new IllegalArgumentException("Type \'" + type.toString() + "\'
not supported.");
+ }
+
+ @Override
+ public Function<Object, Object> visit(ArrowType.Map type) {
+ throw new IllegalArgumentException("Type \'" + type.toString() + "\'
not supported.");
+ }
+
+ @Override
+ public Function<Object, Object> visit(ArrowType.Duration type) {
+ throw new IllegalArgumentException("Type \'" + type.toString() + "\'
not supported.");
+ }
+
+ @Override
+ public Function<Object, Object> visit(ArrowType.Int type) {
+ return null;
+ }
+
+ @Override
+ public Function<Object, Object> visit(ArrowType.FloatingPoint type) {
+ return null;
+ }
+
+ @Override
+ public Function<Object, Object> visit(ArrowType.Utf8 type) {
+ return (Object text) -> ((Text) text).toString();
+ }
+
+ @Override
+ public Function<Object, Object> visit(ArrowType.Binary type) {
+ return null;
+ }
+
+ @Override
+ public Function<Object, Object> visit(ArrowType.FixedSizeBinary type) {
+ return null;
+ }
+
+ @Override
+ public Function<Object, Object> visit(ArrowType.Bool type) {
+ return null;
+ }
+
+ @Override
+ public Function<Object, Object> visit(ArrowType.Decimal type) {
+ throw new IllegalArgumentException("Type \'" + type.toString() + "\'
not supported.");
+ }
+
+ @Override
+ public Function<Object, Object> visit(ArrowType.Date type) {
+ throw new IllegalArgumentException("Type \'" + type.toString() + "\'
not supported.");
+ }
+
+ @Override
+ public Function<Object, Object> visit(ArrowType.Time type) {
+ throw new IllegalArgumentException("Type \'" + type.toString() + "\'
not supported.");
+ }
+
+ @Override
+ public Function<Object, Object> visit(ArrowType.Timestamp type) {
+ DateTimeZone tz = DateTimeZone.forID(type.getTimezone());
Review comment:
is it ok for tz to be null or empty string here? I forget the details on
the java implementation but the Arrow spec differentiates between timestamps
[with/without
timezones](https://github.com/apache/arrow/blob/master/format/Schema.fbs#L178)
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Issue Time Tracking
-------------------
Worklog Id: (was: 378554)
Time Spent: 10h 10m (was: 10h)
> BigQuery IO should support read/write in Arrow format
> -----------------------------------------------------
>
> Key: BEAM-8933
> URL: https://issues.apache.org/jira/browse/BEAM-8933
> Project: Beam
> Issue Type: Improvement
> Components: io-java-gcp
> Reporter: Kirill Kozlov
> Assignee: Kirill Kozlov
> Priority: Major
> Time Spent: 10h 10m
> Remaining Estimate: 0h
>
> As of right now BigQuery uses Avro format for reading and writing.
> We should add a config to BigQueryIO to specify which format to use: Arrow or
> Avro (with Avro as default).
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