ObjectSerializer.cs

// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License.

using System;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
using Azure.Core.Pipeline;

namespace Azure.Core.Serialization
{
    /// <summary>
    /// An abstraction for reading typed objects.
    /// </summary>
    public abstract class ObjectSerializer
    {
        /// <summary>
        /// Convert the provided value to it's binary representation and write it to <see cref="System.IO.Stream"/>.
        /// </summary>
        /// <param name="stream">The <see cref="System.IO.Stream"/> to write to.</param>
        /// <param name="value">The value to convert.</param>
        /// <param name="inputType">The type of the <paramref name="value"/> to convert.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> to use during serialization.</param>
        public abstract void Serialize(Stream stream, object? value, Type inputType, CancellationToken cancellationToken);

        /// <summary>
        /// Convert the provided value to it's binary representation and write it to <see cref="System.IO.Stream"/>.
        /// </summary>
        /// <param name="stream">The <see cref="System.IO.Stream"/> to write to.</param>
        /// <param name="value">The value to convert.</param>
        /// <param name="inputType">The type of the <paramref name="value"/> to convert.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> to use during serialization.</param>
        public abstract ValueTask SerializeAsync(Stream stream, object? value, Type inputType, CancellationToken cancellationToken);

        /// <summary>
        /// Read the binary representation into a <paramref name="returnType"/>.
        /// The Stream will be read to completion.
        /// </summary>
        /// <param name="stream">The <see cref="System.IO.Stream"/> to read from.</param>
        /// <param name="returnType">The type of the object to convert to and return.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> to use during deserialization.</param>
        public abstract object? Deserialize(Stream stream, Type returnType, CancellationToken cancellationToken);

        /// <summary>
        /// Read the binary representation into a <paramref name="returnType"/>.
        /// The Stream will be read to completion.
        /// </summary>
        /// <param name="stream">The <see cref="System.IO.Stream"/> to read from.</param>
        /// <param name="returnType">The type of the object to convert to and return.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> to use during deserialization.</param>
        public abstract ValueTask<object?> DeserializeAsync(Stream stream, Type returnType, CancellationToken cancellationToken);

        /// <summary>
        /// Convert the provided value to it's binary representation and return it as a <see cref="BinaryData"/> instance.
        /// </summary>
        /// <param name="value">The value to convert.</param>
        /// <param name="inputType">The type to use when serializing <paramref name="value"/>. If omitted, the type will be determined using <see cref="object.GetType"/>().</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> to use during serialization.</param>
        /// <returns>The object's binary representation as <see cref="BinaryData"/>.</returns>
        public virtual BinaryData Serialize(object? value, Type? inputType = default, CancellationToken cancellationToken = default) =>
            SerializeToBinaryDataInternalAsync(value, inputType, false, cancellationToken).EnsureCompleted();

        /// <summary>
        /// Convert the provided value to it's binary representation and return it as a <see cref="BinaryData"/> instance.
        /// </summary>
        /// <param name="value">The value to convert.</param>
        /// <param name="inputType">The type to use when serializing <paramref name="value"/>. If omitted, the type will be determined using <see cref="object.GetType"/>().</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> to use during serialization.</param>
        /// <returns>The object's binary representation as <see cref="BinaryData"/>.</returns>
        public virtual async ValueTask<BinaryData> SerializeAsync(object? value, Type? inputType = default, CancellationToken cancellationToken = default) =>
            await SerializeToBinaryDataInternalAsync(value, inputType, true, cancellationToken).ConfigureAwait(false);

        private async ValueTask<BinaryData> SerializeToBinaryDataInternalAsync(object? value, Type? inputType, bool async, CancellationToken cancellationToken)
        {
            using var stream = new MemoryStream();
            inputType ??= value?.GetType() ?? typeof(object);
            if (async)
            {
                await SerializeAsync(stream, value, inputType, cancellationToken).ConfigureAwait(false);
            }
            else
            {
                Serialize(stream, value, inputType, cancellationToken);
            }
            return new BinaryData(stream.GetBuffer().AsMemory(0, (int)stream.Position));
        }
    }
}