| | | 1 | | // Licensed to the .NET Foundation under one or more agreements. |
| | | 2 | | // The .NET Foundation licenses this file to you under the MIT license. |
| | | 3 | | |
| | | 4 | | using System.Collections.Generic; |
| | | 5 | | using System.Diagnostics; |
| | | 6 | | |
| | | 7 | | namespace System.Text.Json.Serialization |
| | | 8 | | { |
| | | 9 | | /// <summary> |
| | | 10 | | /// The default ReferenceResolver implementation to handle duplicate object references. |
| | | 11 | | /// </summary> |
| | | 12 | | internal sealed class PreserveReferenceResolver : ReferenceResolver |
| | | 13 | | { |
| | | 14 | | private uint _referenceCount; |
| | | 15 | | private readonly Dictionary<string, object>? _referenceIdToObjectMap; |
| | | 16 | | private readonly Dictionary<object, string>? _objectToReferenceIdMap; |
| | | 17 | | |
| | 0 | 18 | | public PreserveReferenceResolver(bool writing) |
| | 0 | 19 | | { |
| | 0 | 20 | | if (writing) |
| | 0 | 21 | | { |
| | | 22 | | // Comparer used here does a reference equality comparison on serialization, which is where we use the o |
| | 0 | 23 | | _objectToReferenceIdMap = new Dictionary<object, string>(ReferenceEqualityComparer.Instance); |
| | 0 | 24 | | } |
| | | 25 | | else |
| | 0 | 26 | | { |
| | 0 | 27 | | _referenceIdToObjectMap = new Dictionary<string, object>(); |
| | 0 | 28 | | } |
| | 0 | 29 | | } |
| | | 30 | | |
| | | 31 | | public override void AddReference(string referenceId, object value) |
| | 0 | 32 | | { |
| | 0 | 33 | | Debug.Assert(_referenceIdToObjectMap != null); |
| | | 34 | | |
| | 0 | 35 | | if (!_referenceIdToObjectMap.TryAdd(referenceId, value)) |
| | 0 | 36 | | { |
| | 0 | 37 | | ThrowHelper.ThrowJsonException_MetadataDuplicateIdFound(referenceId); |
| | | 38 | | } |
| | 0 | 39 | | } |
| | | 40 | | |
| | | 41 | | public override string GetReference(object value, out bool alreadyExists) |
| | 0 | 42 | | { |
| | 0 | 43 | | Debug.Assert(_objectToReferenceIdMap != null); |
| | | 44 | | |
| | 0 | 45 | | if (_objectToReferenceIdMap.TryGetValue(value, out string? referenceId)) |
| | 0 | 46 | | { |
| | 0 | 47 | | alreadyExists = true; |
| | 0 | 48 | | } |
| | | 49 | | else |
| | 0 | 50 | | { |
| | 0 | 51 | | _referenceCount++; |
| | 0 | 52 | | referenceId = _referenceCount.ToString(); |
| | 0 | 53 | | _objectToReferenceIdMap.Add(value, referenceId); |
| | 0 | 54 | | alreadyExists = false; |
| | 0 | 55 | | } |
| | | 56 | | |
| | 0 | 57 | | return referenceId; |
| | 0 | 58 | | } |
| | | 59 | | |
| | | 60 | | public override object ResolveReference(string referenceId) |
| | 0 | 61 | | { |
| | 0 | 62 | | Debug.Assert(_referenceIdToObjectMap != null); |
| | | 63 | | |
| | 0 | 64 | | if (!_referenceIdToObjectMap.TryGetValue(referenceId, out object? value)) |
| | 0 | 65 | | { |
| | 0 | 66 | | ThrowHelper.ThrowJsonException_MetadataReferenceNotFound(referenceId); |
| | | 67 | | } |
| | | 68 | | |
| | 0 | 69 | | return value; |
| | 0 | 70 | | } |
| | | 71 | | } |
| | | 72 | | } |