io.axoniq.axondb.client.axon.GrpcMetaDataConverter Maven / Gradle / Ivy
/*
* Copyright (c) 2017. AxonIQ
* Licensed 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 io.axoniq.axondb.client.axon;
import com.google.protobuf.ByteString;
import io.axoniq.platform.MetaDataValue;
import org.axonframework.messaging.MetaData;
import org.axonframework.serialization.SerializedObject;
import org.axonframework.serialization.Serializer;
import org.axonframework.serialization.SimpleSerializedObject;
import java.util.HashMap;
import java.util.Map;
import static org.axonframework.common.ObjectUtils.getOrDefault;
/**
* Utility class for converting gRPC MetaData entries into a Java Map and vice versa.
*
* To optimize communication and minimize the loss of data structure, the MetaDataValue entries used in gRPC
* distinguish between numerical values (double or long), Strings, booleans and arbitrary objects. The latter group is
* converted to and from a {@code byte[]} using the configured Serializer.
*/
public class GrpcMetaDataConverter {
private final Serializer serializer;
/**
* Initialize the converter, using the given {@code serializer} to serialize Objects
*
* @param serializer The serialize to serialize objects with
*/
public GrpcMetaDataConverter(Serializer serializer) {
this.serializer = serializer;
}
/**
* Convert the given {@code value} into a {@link MetaDataValue}, attempting to maintain the source type as much as
* possible in the returned {@link MetaDataValue}.
*
* - A CharSequence (such as String) is stored as a 'string'
* - A Float or Double values is represented as a 'double'
* - A Number that is not a Double or Float is represented as a 'sint64'
* - A Boolean is represented as a 'bool'
* - Any other object is serialized and stored as bytes
*
*
* @param value The value to convert
* @return The protobuf representation of the given value
*/
public MetaDataValue convertToMetaDataValue(Object value) {
MetaDataValue.Builder builder = MetaDataValue.newBuilder();
if (value instanceof CharSequence) {
builder.setTextValue(value.toString());
} else if (value instanceof Double || value instanceof Float) {
builder.setDoubleValue(((Number) value).doubleValue());
} else if (value instanceof Number) {
builder.setNumberValue(((Number) value).longValue());
} else if (value instanceof Boolean) {
builder.setBooleanValue((Boolean) value);
} else {
SerializedObject serializedObject = serializer.serialize(value, byte[].class);
builder.setBytesValue(io.axoniq.platform.SerializedObject.newBuilder()
.setType(serializedObject.getType().getName())
.setData(ByteString.copyFrom(serializedObject.getData()))
.setRevision(getOrDefault(serializedObject.getType().getRevision(), ""))
.build());
}
return builder.build();
}
/**
* Convert the given map of MetaDataValues to a Map containing the Java representations of each MetaDataValue.
*
* See {@link #convertToMetaDataValue(Object)} for details about the mapping.
*
* @param metaDataMap a Map containing MetaDataValue representations of each MetaData key
* @return a map containing the same keys, referencing to the Java representation of each corresponding value in
* the given {@code metaDataMap}
*/
public MetaData convert(Map metaDataMap) {
if (metaDataMap.isEmpty()) {
return MetaData.emptyInstance();
}
Map metaData = new HashMap<>(metaDataMap.size());
metaDataMap.forEach((k, v) -> metaData.put(k, convertFromMetaDataValue(v)));
return MetaData.from(metaData);
}
/**
* Convert the given MetaDataValue to its Java representation.
*
* See {@link #convertToMetaDataValue(Object)} for details about the mapping.
*
* @param value The value to convert
* @return The Java object representing the same value
*/
public Object convertFromMetaDataValue(MetaDataValue value) {
switch (value.getDataCase()) {
case TEXT_VALUE:
return value.getTextValue();
case BYTES_VALUE:
io.axoniq.platform.SerializedObject bytesValue = value.getBytesValue();
return serializer.deserialize(new SimpleSerializedObject<>(bytesValue.getData().toByteArray(),
byte[].class,
bytesValue.getType(),
bytesValue.getRevision()));
case DATA_NOT_SET:
return null;
case DOUBLE_VALUE:
return value.getDoubleValue();
case NUMBER_VALUE:
return value.getNumberValue();
case BOOLEAN_VALUE:
return value.getBooleanValue();
}
return null;
}
}