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PARQUET-968 Add Hive/Presto support in ProtoParquet #411

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PARQUET-968 Add Hive/Presto support in ProtoParquet #411

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5cf9248
PARQUET-968 Add Hive support in ProtoParquet
Apr 29, 2017
a8bd704
Pick up commit from @andredasilvapinto
Sep 5, 2017
16eafcb
PARQUET-968 add proto flag to enable writing using specs-compliant sc…
BenoitHanotte Apr 13, 2018
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126 changes: 125 additions & 1 deletion parquet-protobuf/src/main/java/org/apache/parquet/proto/ProtoMessageConverter.java
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Original file line number Diff line number Diff line change
Expand Up @@ -24,12 +24,14 @@
import com.twitter.elephantbird.util.Protobufs;
import org.apache.parquet.column.Dictionary;
import org.apache.parquet.io.InvalidRecordException;
import org.apache.parquet.io.ParquetDecodingException;
import org.apache.parquet.io.api.Binary;
import org.apache.parquet.io.api.Converter;
import org.apache.parquet.io.api.GroupConverter;
import org.apache.parquet.io.api.PrimitiveConverter;
import org.apache.parquet.schema.GroupType;
import org.apache.parquet.schema.IncompatibleSchemaModificationException;
import org.apache.parquet.schema.OriginalType;
import org.apache.parquet.schema.Type;

import java.util.HashMap;
Expand Down Expand Up @@ -129,10 +131,15 @@ public void add(Object value) {
};
}

if (OriginalType.LIST == parquetType.getOriginalType()) {
return new ListConverter(parentBuilder, fieldDescriptor, parquetType);
}
if (OriginalType.MAP == parquetType.getOriginalType()) {
return new MapConverter(parentBuilder, fieldDescriptor, parquetType);
}
return newScalarConverter(parent, parentBuilder, fieldDescriptor, parquetType);
}


private Converter newScalarConverter(ParentValueContainer pvc, Message.Builder parentBuilder, Descriptors.FieldDescriptor fieldDescriptor, Type parquetType) {

JavaType javaType = fieldDescriptor.getJavaType();
Expand Down Expand Up @@ -345,4 +352,121 @@ public void addBinary(Binary binary) {
}

}

/**
* This class unwraps the additional LIST wrapper and makes it possible to read the underlying data and then convert
* it to protobuf.
* <p>
* Consider the following protobuf schema:
* message SimpleList {
* repeated int64 first_array = 1;
* }
* <p>
* A LIST wrapper is created in parquet for the above mentioned protobuf schema:
* message SimpleList {
* optional group first_array (LIST) = 1 {
* repeated group list {
* optional int32 element;
* }
* }
* }
* <p>
* The LIST wrappers are used by 3rd party tools, such as Hive, to read parquet arrays. The wrapper contains
* a repeated group named 'list', itself containing only one field called 'element' of the type of the repeated
* object (can be a primitive as in this example or a group in case of a repeated message in protobuf).
*/
final class ListConverter extends GroupConverter {
private final Converter converter;

public ListConverter(Message.Builder parentBuilder, Descriptors.FieldDescriptor fieldDescriptor, Type parquetType) {
OriginalType originalType = parquetType.getOriginalType();
if (originalType != OriginalType.LIST || parquetType.isPrimitive()) {
throw new ParquetDecodingException("Expected LIST wrapper. Found: " + originalType + " instead.");
}

GroupType rootWrapperType = parquetType.asGroupType();
if (!rootWrapperType.containsField("list") || rootWrapperType.getType("list").isPrimitive()) {
throw new ParquetDecodingException("Expected repeated 'list' group inside LIST wrapperr but got: " + rootWrapperType);
}

GroupType listType = rootWrapperType.getType("list").asGroupType();
if (!listType.containsField("element")) {
throw new ParquetDecodingException("Expected 'element' inside repeated list group but got: " + listType);
}

Type elementType = listType.getType("element");
converter = newMessageConverter(parentBuilder, fieldDescriptor, elementType);
}

@Override
public Converter getConverter(int fieldIndex) {
if (fieldIndex > 0) {
throw new ParquetDecodingException("Unexpected multiple fields in the LIST wrapper");
}

return new GroupConverter() {
@Override
public Converter getConverter(int fieldIndex) {
return converter;
}

@Override
public void start() {

}

@Override
public void end() {

}
};
}

@Override
public void start() {

}

@Override
public void end() {

}
}


final class MapConverter extends GroupConverter {
private final Converter converter;

public MapConverter(Message.Builder parentBuilder, Descriptors.FieldDescriptor fieldDescriptor, Type parquetType) {
OriginalType originalType = parquetType.getOriginalType();
if (originalType != OriginalType.MAP) {
throw new ParquetDecodingException("Expected MAP wrapper. Found: " + originalType + " instead.");
}

Type parquetSchema;
if (parquetType.asGroupType().containsField("key_value")){
parquetSchema = parquetType.asGroupType().getType("key_value");
} else {
throw new ParquetDecodingException("Expected map but got: " + parquetType);
}

converter = newMessageConverter(parentBuilder, fieldDescriptor, parquetSchema);
}

@Override
public Converter getConverter(int fieldIndex) {
if (fieldIndex > 0) {
throw new ParquetDecodingException("Unexpected multiple fields in the MAP wrapper");
}
return converter;
}

@Override
public void start() {
}

@Override
public void end() {
}
}
}
169 changes: 133 additions & 36 deletions parquet-protobuf/src/main/java/org/apache/parquet/proto/ProtoSchemaConverter.java
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
/*
/*
* 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
Expand All @@ -18,30 +18,27 @@
*/
package org.apache.parquet.proto;

import static org.apache.parquet.schema.OriginalType.ENUM;
import static org.apache.parquet.schema.OriginalType.UTF8;
import static org.apache.parquet.schema.PrimitiveType.PrimitiveTypeName.BINARY;
import static org.apache.parquet.schema.PrimitiveType.PrimitiveTypeName.BOOLEAN;
import static org.apache.parquet.schema.PrimitiveType.PrimitiveTypeName.DOUBLE;
import static org.apache.parquet.schema.PrimitiveType.PrimitiveTypeName.FLOAT;
import static org.apache.parquet.schema.PrimitiveType.PrimitiveTypeName.INT32;
import static org.apache.parquet.schema.PrimitiveType.PrimitiveTypeName.INT64;

import java.util.List;

import com.google.protobuf.Descriptors;
import com.google.protobuf.Descriptors.FieldDescriptor;
import com.google.protobuf.Descriptors.FieldDescriptor.JavaType;
import com.google.protobuf.Message;
import com.twitter.elephantbird.util.Protobufs;
import org.apache.parquet.schema.MessageType;
import org.apache.parquet.schema.OriginalType;
import org.apache.parquet.schema.PrimitiveType.PrimitiveTypeName;
import org.apache.parquet.schema.Type;
import org.apache.parquet.schema.Types;
import org.apache.parquet.schema.Types.Builder;
import org.apache.parquet.schema.Types.GroupBuilder;

import com.google.protobuf.Descriptors;
import com.google.protobuf.Descriptors.FieldDescriptor.JavaType;
import com.google.protobuf.Message;
import com.twitter.elephantbird.util.Protobufs;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.List;

import static org.apache.parquet.schema.OriginalType.ENUM;
import static org.apache.parquet.schema.OriginalType.UTF8;
import static org.apache.parquet.schema.PrimitiveType.PrimitiveTypeName.*;

/**
* <p/>
* Converts a Protocol Buffer Descriptor into a Parquet schema.
Expand All @@ -51,6 +48,22 @@
public class ProtoSchemaConverter {

private static final Logger LOG = LoggerFactory.getLogger(ProtoSchemaConverter.class);
private final boolean parquetSpecsCompliant;

public ProtoSchemaConverter() {
this(false);
}

/**
* Instanciate a schema converter to get the parquet schema corresponding to protobuf classes.
* @param parquetSpecsCompliant If set to false, the parquet schema generated will be using the old
* schema style (prior to PARQUET-968) to provide backward-compatibility
* but which does not use LIST and MAP wrappers around collections as required
* by the parquet specifications. If set to true, specs compliant schemas are used.
*/
public ProtoSchemaConverter(boolean parquetSpecsCompliant) {
this.parquetSpecsCompliant = parquetSpecsCompliant;
}

public MessageType convert(Class<? extends Message> protobufClass) {
LOG.debug("Converting protocol buffer class \"" + protobufClass + "\" to parquet schema.");
Expand All @@ -63,8 +76,8 @@ public MessageType convert(Class<? extends Message> protobufClass) {
}

/* Iterates over list of fields. **/
private <T> GroupBuilder<T> convertFields(GroupBuilder<T> groupBuilder, List<Descriptors.FieldDescriptor> fieldDescriptors) {
for (Descriptors.FieldDescriptor fieldDescriptor : fieldDescriptors) {
private <T> GroupBuilder<T> convertFields(GroupBuilder<T> groupBuilder, List<FieldDescriptor> fieldDescriptors) {
for (FieldDescriptor fieldDescriptor : fieldDescriptors) {
groupBuilder =
addField(fieldDescriptor, groupBuilder)
.id(fieldDescriptor.getNumber())
Expand All @@ -73,7 +86,7 @@ private <T> GroupBuilder<T> convertFields(GroupBuilder<T> groupBuilder, List<Des
return groupBuilder;
}

private Type.Repetition getRepetition(Descriptors.FieldDescriptor descriptor) {
private Type.Repetition getRepetition(FieldDescriptor descriptor) {
if (descriptor.isRequired()) {
return Type.Repetition.REQUIRED;
} else if (descriptor.isRepeated()) {
Expand All @@ -83,26 +96,110 @@ private Type.Repetition getRepetition(Descriptors.FieldDescriptor descriptor) {
}
}

private <T> Builder<? extends Builder<?, GroupBuilder<T>>, GroupBuilder<T>> addField(Descriptors.FieldDescriptor descriptor, GroupBuilder<T> builder) {
Type.Repetition repetition = getRepetition(descriptor);
JavaType javaType = descriptor.getJavaType();
private <T> Builder<? extends Builder<?, GroupBuilder<T>>, GroupBuilder<T>> addField(FieldDescriptor descriptor, final GroupBuilder<T> builder) {
if (descriptor.getJavaType() == JavaType.MESSAGE) {
return addMessageField(descriptor, builder);
}

ParquetType parquetType = getParquetType(descriptor);
if (descriptor.isRepeated() && parquetSpecsCompliant) {
// the old schema style did not include the LIST wrapper around repeated fields
return addRepeatedPrimitive(descriptor, parquetType.primitiveType, parquetType.originalType, builder);
}

return builder.primitive(parquetType.primitiveType, getRepetition(descriptor)).as(parquetType.originalType);
}

private <T> Builder<? extends Builder<?, GroupBuilder<T>>, GroupBuilder<T>> addRepeatedPrimitive(FieldDescriptor descriptor,
PrimitiveTypeName primitiveType,
OriginalType originalType,
final GroupBuilder<T> builder) {
return builder
.group(Type.Repetition.OPTIONAL).as(OriginalType.LIST)
.group(Type.Repetition.REPEATED)
.primitive(primitiveType, Type.Repetition.REQUIRED).as(originalType)
.named("element")
.named("list");
}

private <T> GroupBuilder<GroupBuilder<T>> addRepeatedMessage(FieldDescriptor descriptor, GroupBuilder<T> builder) {
GroupBuilder<GroupBuilder<GroupBuilder<GroupBuilder<T>>>> result =
builder
.group(Type.Repetition.OPTIONAL).as(OriginalType.LIST)
.group(Type.Repetition.REPEATED)
.group(Type.Repetition.OPTIONAL);

convertFields(result, descriptor.getMessageType().getFields());

return result.named("element").named("list");
}

private <T> GroupBuilder<GroupBuilder<T>> addMessageField(FieldDescriptor descriptor, final GroupBuilder<T> builder) {
if (descriptor.isMapField() && parquetSpecsCompliant) {
// the old schema style did not include the MAP wrapper around map groups
return addMapField(descriptor, builder);
}
if (descriptor.isRepeated() && parquetSpecsCompliant) {
// the old schema style did not include the LIST wrapper around repeated messages
return addRepeatedMessage(descriptor, builder);
}

// Plain message
GroupBuilder<GroupBuilder<T>> group = builder.group(getRepetition(descriptor));
convertFields(group, descriptor.getMessageType().getFields());
return group;
}

private <T> GroupBuilder<GroupBuilder<T>> addMapField(FieldDescriptor descriptor, final GroupBuilder<T> builder) {
List<FieldDescriptor> fields = descriptor.getMessageType().getFields();
if (fields.size() != 2) {
throw new UnsupportedOperationException("Expected two fields for the map (key/value), but got: " + fields);
}

ParquetType mapKeyParquetType = getParquetType(fields.get(0));

GroupBuilder<GroupBuilder<GroupBuilder<T>>> group = builder
.group(Type.Repetition.OPTIONAL).as(OriginalType.MAP) // only optional maps are allowed in Proto3
.group(Type.Repetition.REPEATED) // key_value wrapper
.primitive(mapKeyParquetType.primitiveType, Type.Repetition.REQUIRED).as(mapKeyParquetType.originalType).named("key");

return addField(fields.get(1), group).named("value")
.named("key_value");
}

private ParquetType getParquetType(FieldDescriptor fieldDescriptor) {

JavaType javaType = fieldDescriptor.getJavaType();
switch (javaType) {
case BOOLEAN: return builder.primitive(BOOLEAN, repetition);
case INT: return builder.primitive(INT32, repetition);
case LONG: return builder.primitive(INT64, repetition);
case FLOAT: return builder.primitive(FLOAT, repetition);
case DOUBLE: return builder.primitive(DOUBLE, repetition);
case BYTE_STRING: return builder.primitive(BINARY, repetition);
case STRING: return builder.primitive(BINARY, repetition).as(UTF8);
case MESSAGE: {
GroupBuilder<GroupBuilder<T>> group = builder.group(repetition);
convertFields(group, descriptor.getMessageType().getFields());
return group;
}
case ENUM: return builder.primitive(BINARY, repetition).as(ENUM);
case INT: return ParquetType.of(INT32);
case LONG: return ParquetType.of(INT64);
case DOUBLE: return ParquetType.of(DOUBLE);
case BOOLEAN: return ParquetType.of(BOOLEAN);
case FLOAT: return ParquetType.of(FLOAT);
case STRING: return ParquetType.of(BINARY, UTF8);
case ENUM: return ParquetType.of(BINARY, ENUM);
case BYTE_STRING: return ParquetType.of(BINARY);
default:
throw new UnsupportedOperationException("Cannot convert Protocol Buffer: unknown type " + javaType);
}
}

private static class ParquetType {
PrimitiveTypeName primitiveType;
OriginalType originalType;

private ParquetType(PrimitiveTypeName primitiveType, OriginalType originalType) {
this.primitiveType = primitiveType;
this.originalType = originalType;
}

public static ParquetType of(PrimitiveTypeName primitiveType, OriginalType originalType) {
return new ParquetType(primitiveType, originalType);
}

public static ParquetType of(PrimitiveTypeName primitiveType) {
return of(primitiveType, null);
}
}

}
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