| #region License |
| |
| /* |
| * 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 |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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. |
| */ |
| |
| #endregion |
| |
| using System.IO; |
| using System.Threading; |
| using System.Threading.Tasks; |
| |
| namespace Gremlin.Net.Structure.IO.GraphBinary |
| { |
| /// <summary> |
| /// Allows to deserialize objects from GraphBinary. |
| /// </summary> |
| public class GraphBinaryReader |
| { |
| private readonly TypeSerializerRegistry _registry; |
| |
| /// <summary> |
| /// Initializes a new instance of the <see cref="GraphBinaryReader" /> class. |
| /// </summary> |
| /// <param name="registry">The <see cref="TypeSerializerRegistry"/> to use for deserialization.</param> |
| public GraphBinaryReader(TypeSerializerRegistry? registry = null) |
| { |
| _registry = registry ?? TypeSerializerRegistry.Instance; |
| } |
| |
| /// <summary> |
| /// Reads only the value for a specific type <typeparamref name="T"/>. |
| /// </summary> |
| /// <param name="stream">The GraphBinary data to parse.</param> |
| /// <param name="cancellationToken">The token to cancel the operation. The default value is None.</param> |
| /// <typeparam name="T">The type of the object to read.</typeparam> |
| /// <returns>The read value.</returns> |
| public async Task<object?> ReadNullableValueAsync<T>(Stream stream, |
| CancellationToken cancellationToken = default) |
| { |
| var typedSerializer = _registry.GetSerializerFor(typeof(T)); |
| return await typedSerializer.ReadNullableValueAsync(stream, this, cancellationToken) |
| .ConfigureAwait(false); |
| } |
| |
| /// <summary> |
| /// Reads only the value for a specific type <typeparamref name="T"/>. |
| /// </summary> |
| /// <param name="stream">The GraphBinary data to parse.</param> |
| /// <param name="cancellationToken">The token to cancel the operation. The default value is None.</param> |
| /// <typeparam name="T">The type of the object to read.</typeparam> |
| /// <returns>The read value.</returns> |
| public async Task<object> ReadNonNullableValueAsync<T>(Stream stream, |
| CancellationToken cancellationToken = default) |
| { |
| var typedSerializer = _registry.GetSerializerFor(typeof(T)); |
| return await typedSerializer.ReadNonNullableValueAsync(stream, this, cancellationToken) |
| .ConfigureAwait(false); |
| } |
| |
| /// <summary> |
| /// Reads the type code, information and value with fully-qualified format. |
| /// </summary> |
| /// <param name="stream">The GraphBinary data to parse.</param> |
| /// <param name="cancellationToken">The token to cancel the operation. The default value is None.</param> |
| /// <returns>The read value.</returns> |
| public async Task<object?> ReadAsync(Stream stream, CancellationToken cancellationToken = default) |
| { |
| var type = DataType.FromTypeCode(await stream.ReadByteAsync(cancellationToken).ConfigureAwait(false)); |
| |
| if (type == DataType.UnspecifiedNull) |
| { |
| await stream.ReadByteAsync(cancellationToken).ConfigureAwait(false); // read value byte to advance the index |
| return null; |
| } |
| |
| ITypeSerializer typeSerializer; |
| if (type != DataType.Custom) |
| { |
| typeSerializer = _registry.GetSerializerFor(type); |
| } |
| else |
| { |
| var customTypeName = (string)await ReadNonNullableValueAsync<string>(stream, cancellationToken) |
| .ConfigureAwait(false); |
| typeSerializer = _registry.GetSerializerForCustomType(customTypeName); |
| } |
| |
| return await typeSerializer.ReadAsync(stream, this, cancellationToken).ConfigureAwait(false); |
| } |
| } |
| } |