Generate unique link target (#973)

dotnet · Oct 29, 2022 · 967440f · 967440f
1 parent 2a8f3da
commit 967440f
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Showing 3 changed files with 62 additions and 7 deletions.
diff --git a/src/Documentation/DocumentationGenerator.cs b/src/Documentation/DocumentationGenerator.cs
@@ -965,7 +965,7 @@ private IEnumerable<DocumentationGeneratorResult> GenerateMembers(TypeDocumentat
 
                                 foreach (ISymbol overloadSymbol in grouping.OrderBy(f => f.ToDisplayString(format, additionalOptions)))
                                 {
-                                    string id = DocumentationUrlProvider.GetFragment(overloadSymbol);
+                                    string id = UrlProvider.GetFragment(overloadSymbol);
 
                                     writer.WriteLinkTarget(id);
                                     writer.WriteStartHeading(2);

diff --git a/src/Documentation/DocumentationWriter.cs b/src/Documentation/DocumentationWriter.cs
@@ -1961,7 +1961,7 @@ string GetLocalLinkTarget()
                             if (en.MoveNext()
                                 && en.MoveNext())
                             {
-                                return DocumentationUrlProvider.GetFragment(symbol);
+                                return UrlProvider.GetFragment(symbol);
                             }
                         }
                     }

diff --git a/src/Documentation/UrlProviders/DocumentationUrlProvider.cs b/src/Documentation/UrlProviders/DocumentationUrlProvider.cs
@@ -1,17 +1,19 @@
 // Copyright (c) Josef Pihrt and Contributors. Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Diagnostics;
+using System.Globalization;
 using System.Text;
-using System.Text.RegularExpressions;
 using Microsoft.CodeAnalysis;
 using Roslynator.Text;
 
 namespace Roslynator.Documentation
 {
     public abstract class DocumentationUrlProvider
     {
-        private static readonly Regex _notWordCharOrUnderscoreRegex = new(@"[^\w_]");
+        private readonly Dictionary<string, string> _symbolToLinkMap = new();
 
         protected DocumentationUrlProvider(UrlSegmentProvider segmentProvider, IEnumerable<ExternalUrlProvider> externalProviders = null)
         {
@@ -115,13 +117,66 @@ internal string GetUrlToRoot(int depth, char separator, bool scrollToContent = f
             return StringBuilderCache.GetStringAndFree(sb);
         }
 
-        internal static string GetFragment(ISymbol symbol)
+        internal string GetFragment(ISymbol symbol)
         {
             string id = symbol.GetDocumentationCommentId();
 
-            id = TextUtility.RemovePrefixFromDocumentationCommentId(id);
+            if (!_symbolToLinkMap.TryGetValue(id, out string link))
+            {
+                int hashCode = GetDeterministicHashCode(id);
+
+                long linkCode;
+                if (hashCode >= 0)
+                {
+                    linkCode = (uint)hashCode;
+                }
+                else
+                {
+                    linkCode = int.MaxValue + (uint)Math.Abs(hashCode);
+                }
+
+                link = linkCode.ToString(CultureInfo.InvariantCulture);
+
+                if (_symbolToLinkMap.ContainsValue(link))
+                {
+                    Debug.Fail(id);
+
+                    linkCode += uint.MaxValue;
+                    link = linkCode.ToString(CultureInfo.InvariantCulture);
+
+                    while (_symbolToLinkMap.ContainsValue(link))
+                    {
+                        linkCode++;
+                        link = linkCode.ToString(CultureInfo.InvariantCulture);
+                    }
+                }
+
+                _symbolToLinkMap.Add(id, link);
+            }
+
+            return link;
+        }
 
-            return _notWordCharOrUnderscoreRegex.Replace(id, "_");
+        // https://andrewlock.net/why-is-string-gethashcode-different-each-time-i-run-my-program-in-net-core/#a-deterministic-gethashcode-implementation
+        private static int GetDeterministicHashCode(string s)
+        {
+            unchecked
+            {
+                int hash1 = (5381 << 16) + 5381;
+                int hash2 = hash1;
+
+                for (int i = 0; i < s.Length; i += 2)
+                {
+                    hash1 = ((hash1 << 5) + hash1) ^ s[i];
+
+                    if (i == s.Length - 1)
+                        break;
+
+                    hash2 = ((hash2 << 5) + hash2) ^ s[i + 1];
+                }
+
+                return hash1 + (hash2 * 1566083941);
+            }
         }
     }
 }