src/EditorFeatures/Text/Implementation/TextBufferFactoryService/TextBufferCloneServiceFactory.cs - main - githubmirror/roslyn

src/EditorFeatures/Text/Implementation/TextBufferFactoryService/TextBufferCloneServiceFactory.cs

58 строк2 KB

Todd Grunke

Reduce allocations in TextBufferFactoryCloneService.Clone (#82777)

17 мар 2026, 03:46

17 мар 2026, 03:46d2d357d

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System;
using System.Composition;
using Microsoft.CodeAnalysis.Editor;
using Microsoft.CodeAnalysis.Host.Mef;
using Microsoft.VisualStudio.Text;
using Microsoft.VisualStudio.Utilities;

namespace Microsoft.CodeAnalysis.Text.Implementation.TextBufferFactoryService;

[Export(typeof(ITextBufferCloneService)), Shared]
internal sealed class TextBufferCloneService : ITextBufferCloneService
{
    private readonly ITextBufferFactoryService3 _textBufferFactoryService;
    private readonly IContentType _roslynContentType;
    private readonly IContentType _unknownContentType;

    [ImportingConstructor]
    [Obsolete(MefConstruction.ImportingConstructorMessage, error: true)]
    public TextBufferCloneService(
        ITextBufferFactoryService3 textBufferFactoryService,
        IContentTypeRegistryService contentTypeRegistryService)
    {
        _textBufferFactoryService = textBufferFactoryService;

        _roslynContentType = contentTypeRegistryService.GetContentType(ContentTypeNames.RoslynContentType);
        _unknownContentType = contentTypeRegistryService.UnknownContentType;
    }

    public ITextBuffer CloneWithUnknownContentType(SnapshotSpan span)
        => _textBufferFactoryService.CreateTextBuffer(span, _unknownContentType);

    public ITextBuffer CloneWithUnknownContentType(ITextImage textImage)
        => Clone(textImage, _unknownContentType);

    public ITextBuffer CloneWithRoslynContentType(SourceText sourceText)
        => Clone(sourceText, _roslynContentType);

    public ITextBuffer Clone(SourceText sourceText, IContentType contentType)
    {
        // see whether we can do directly via a text image
        var textImage = sourceText.TryFindCorrespondingEditorTextImage();
        if (textImage != null)
        {
            return Clone(textImage, contentType);
        }

        // we can't, so do it through a text reader.
        var reader = new SourceTextReader(sourceText);
        return _textBufferFactoryService.CreateTextBuffer(reader, contentType);
    }

    private ITextBuffer Clone(ITextImage textImage, IContentType contentType)
        => _textBufferFactoryService.CreateTextBuffer(textImage, contentType);
}