/*
 * Copyright 2012-2018 Chronicle Map Contributors
 *
 * 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 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;

/**
 * Serializer of objects to bytes, pairing {@link SizedReader}, which knows the length of serialized
 * form of any object before actual serialization 2) doesn't include that length in the serialized
 * form itself, assuming it will be passed by the {@link ChronicleHash} into {@link
 * SizedReader#read} deserialization method.
 * <p>
 * <p>Read <a href="https://github.com/OpenHFT/Chronicle-Map/blob/ea/docs/CM_Tutorial_DataAccess.adoc">{@code
 * SizedWriter} and {@code SizedReader}</a> and
 * <a href="https://github.com/OpenHFT/Chronicle-Map/blob/ea/docs/CM_Tutorial.adoc#custom-serialization-checklist">custom
 * serialization checklist</a> sections in the Chronicle Map tutorial for more information on this
 * interface, how to implement and use it properly.
 *
 * @param <T> the type of the object marshalled
 * @see SizedReader
 * @see ChronicleHashBuilder#keyMarshallers(SizedReader, SizedWriter)
 * @see ChronicleMapBuilder#valueMarshallers(SizedReader, SizedWriter)
 */
public interface SizedWriter<T> extends Marshallable {

    /**
     * Returns the length (in bytes) of the serialized form of the given object. Serialization form
     * in terms of this interface, i. e. how much bytes are written to {@code out} on
     * {@link #write(Bytes, long, Object) write(out, size, toWrite)} call.
     *
     * @param toWrite the object which serialized form length should be returned
     * @return the length (in bytes) of the serialized form of the given object
     */
    // TODO lift the requirement to give a size first which can involve double serialization.
    long size(@NotNull T toWrite);

    /**
     * Serializes the given object to the given {@code out}, without writing the length of the
     * serialized form itself.
     * <p>
     * <p>Implementation of this method should increment the {@linkplain Bytes#writePosition()
     * position} of the given {@code out} by {@link #size(Object) size(toWrite)}. The given object
     * should be written into these range between the initial {@code bytes}' position and the
     * position after this method call returns.
     *
     * @param out     the {@code Bytes} to write the given object to
     * @param size    the size, returned by {@link #size(Object)} for the given {@code toWrite} object.
     *                it is given, because size might be needed during serialization, and it's computation has
     *                non-constant complexity, i. e. if serializing a {@code CharSequence} using variable-length
     *                encoding like UTF-8.
     * @param toWrite the object to serialize
     * @see SizedReader#read(Bytes, long, Object)
     */
    void write(Bytes out, long size, @NotNull T toWrite);
}
