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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
using System.Collections.Generic;
using System.IO;
using System.Reflection.Metadata;
using System.Formats.Nrbf.Utils;
using System.Diagnostics;
namespace System.Formats.Nrbf;
/// <summary>
/// Represents a single dimensional array of <see langword="string" />.
/// </summary>
/// <remarks>
/// ArraySingleString records are described in <see href="https://learn.microsoft.com/openspecs/windows_protocols/ms-nrbf/3d98fd60-d2b4-448a-ac0b-3cd8dea41f9d">[MS-NRBF] 2.4.3.4</see>.
/// </remarks>
internal sealed class ArraySingleStringRecord : SZArrayRecord<string?>
{
private ArraySingleStringRecord(ArrayInfo arrayInfo) : base(arrayInfo) => Records = [];
public override SerializationRecordType RecordType => SerializationRecordType.ArraySingleString;
/// <inheritdoc />
public override TypeName TypeName => TypeNameHelpers.GetPrimitiveSZArrayTypeName(TypeNameHelpers.StringPrimitiveType);
private List<SerializationRecord> Records { get; }
internal static ArraySingleStringRecord Decode(BinaryReader reader)
=> new(ArrayInfo.Decode(reader));
internal override (AllowedRecordTypes allowed, PrimitiveType primitiveType) GetAllowedRecordType()
{
// An array of string can consist of string(s), null(s) and reference(s) to string(s).
const AllowedRecordTypes AllowedTypes = AllowedRecordTypes.BinaryObjectString
| AllowedRecordTypes.Nulls | AllowedRecordTypes.MemberReference;
return (AllowedTypes, default);
}
private protected override void AddValue(object value) => Records.Add((SerializationRecord)value);
/// <inheritdoc/>
public override string?[] GetArray(bool allowNulls = true)
=> (string?[])(allowNulls ? _arrayNullsAllowed ??= ToArray(true) : _arrayNullsNotAllowed ??= ToArray(false));
private string?[] ToArray(bool allowNulls)
{
string?[] values = new string?[Length];
int valueIndex = 0;
for (int recordIndex = 0; recordIndex < Records.Count; recordIndex++)
{
SerializationRecord record = Records[recordIndex];
if (record is MemberReferenceRecord memberReference)
{
record = memberReference.GetReferencedRecord();
if (record is not BinaryObjectStringRecord)
{
ThrowHelper.ThrowInvalidReference();
}
}
if (record is BinaryObjectStringRecord stringRecord)
{
values[valueIndex++] = stringRecord.Value;
continue;
}
if (!allowNulls)
{
ThrowHelper.ThrowArrayContainedNulls();
}
int nullCount = ((NullsRecord)record).NullCount;
Debug.Assert(nullCount > 0, "All implementations of NullsRecord are expected to return a positive value for NullCount.");
do
{
values[valueIndex++] = null;
nullCount--;
}
while (nullCount > 0);
}
Debug.Assert(valueIndex == values.Length, "We should have traversed the entirety of the newly created array.");
return values;
}
}
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