net.openhft.chronicle.hash.serialization.SizedReader Maven / Gradle / Ivy
/*
* Copyright (C) 2012, 2016 higherfrequencytrading.com
* Copyright (C) 2016 Roman Leventov
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see .
*/
package net.openhft.chronicle.hash.serialization;
import net.openhft.chronicle.bytes.Bytes;
import net.openhft.chronicle.hash.ChronicleHash;
import net.openhft.chronicle.hash.ChronicleHashBuilder;
import net.openhft.chronicle.map.ChronicleMapBuilder;
import net.openhft.chronicle.wire.Marshallable;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
/**
* Deserializer of objects from bytes, pairing {@link SizedWriter}, i. e. assuming the length
* of the serialized form isn't written in the beginning of the serialized form itself, but managed
* by {@link ChronicleHash} implementation and passed to the reading methods.
*
* Read {@code
* SizedWriter} and {@code SizedReader},
* {@link DataAccess}
* and {@code SizedReader} and
* custom
* serialization checklist sections in the Chronicle Map tutorial for more information on this
* interface, how to implement and use it properly.
*
* @param the type of the object deserialized
* @see SizedWriter
* @see ChronicleHashBuilder#keyMarshallers(SizedReader, SizedWriter)
* @see ChronicleHashBuilder#keyReaderAndDataAccess(SizedReader, DataAccess)
* @see ChronicleMapBuilder#valueMarshallers(SizedReader, SizedWriter)
* @see ChronicleMapBuilder#valueReaderAndDataAccess(SizedReader, DataAccess)
*/
public interface SizedReader extends Marshallable {
/**
* Reads and returns the object from {@link Bytes#readPosition()} (i. e. the current position)
* to {@code Bytes.readPosition() + size} in the given {@code in}. Should attempt to reuse the
* given {@code using} object, i. e. to read the deserialized data into the given object. If it
* is possible, this objects then returned from this method. If it is impossible for any reason,
* a new object should be created and returned. The given {@code using} object could be {@code
* null}, in this case read() should always create a new object.
*
* This method should increment the position in the given {@code Bytes} by the given {@code
* size}.
*
* @param in the {@code Bytes} to read the object from
* @param size the size of the serialized form of the returned object
* @param using the object to read the deserialized data into, could be {@code null}
* @return the object read from the bytes, either reused or newly created
*/
@NotNull
T read(Bytes in, long size, @Nullable T using);
}