Replace StringBuilder with ValueStringBuilder in AssemblyName.FullName (

dotnet#66750)
rzikm · Mar 17, 2022 · ac84ea6 · ac84ea6
1 parent 7fc07e9
commit ac84ea6
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Showing 2 changed files with 29 additions and 27 deletions.
diff --git a/src/libraries/Common/src/System/Text/ValueStringBuilder.AppendSpanFormattable.cs b/src/libraries/Common/src/System/Text/ValueStringBuilder.AppendSpanFormattable.cs
@@ -5,7 +5,7 @@ namespace System.Text
 {
  internal ref partial struct ValueStringBuilder
  {
- internal void AppendSpanFormattable<T>(T value, string? format, IFormatProvider? provider) where T : ISpanFormattable
+ internal void AppendSpanFormattable<T>(T value, string? format = null, IFormatProvider? provider = null) where T : ISpanFormattable
  {
  if (value.TryFormat(_chars.Slice(_pos), out int charsWritten, format, provider))
  {

diff --git a/src/libraries/System.Private.CoreLib/src/System/Reflection/AssemblyNameFormatter.cs b/src/libraries/System.Private.CoreLib/src/System/Reflection/AssemblyNameFormatter.cs
@@ -15,31 +15,31 @@ public static string ComputeDisplayName(string name, Version? version, string? c
  const int PUBLIC_KEY_TOKEN_LEN = 8;
  Debug.Assert(name.Length != 0);
 
- StringBuilder sb = new StringBuilder();
- sb.AppendQuoted(name);
+ var vsb = new ValueStringBuilder(stackalloc char[256]);
+ vsb.AppendQuoted(name);
 
  if (version != null)
  {
  Version canonicalizedVersion = version.CanonicalizeVersion();
  if (canonicalizedVersion.Major != ushort.MaxValue)
  {
- sb.Append(", Version=");
- sb.Append(canonicalizedVersion.Major);
+ vsb.Append(", Version=");
+ vsb.AppendSpanFormattable(canonicalizedVersion.Major);
 
  if (canonicalizedVersion.Minor != ushort.MaxValue)
  {
- sb.Append('.');
- sb.Append(canonicalizedVersion.Minor);
+ vsb.Append('.');
+ vsb.AppendSpanFormattable(canonicalizedVersion.Minor);
 
  if (canonicalizedVersion.Build != ushort.MaxValue)
  {
- sb.Append('.');
- sb.Append(canonicalizedVersion.Build);
+ vsb.Append('.');
+ vsb.AppendSpanFormattable(canonicalizedVersion.Build);
 
  if (canonicalizedVersion.Revision != ushort.MaxValue)
  {
- sb.Append('.');
- sb.Append(canonicalizedVersion.Revision);
+ vsb.Append('.');
+ vsb.AppendSpanFormattable(canonicalizedVersion.Revision);
  }
  }
  }
@@ -50,36 +50,38 @@ public static string ComputeDisplayName(string name, Version? version, string? c
  {
  if (cultureName.Length == 0)
  cultureName = "neutral";
- sb.Append(", Culture=");
- sb.AppendQuoted(cultureName);
+ vsb.Append(", Culture=");
+ vsb.AppendQuoted(cultureName);
  }
 
  if (pkt != null)
  {
  if (pkt.Length > PUBLIC_KEY_TOKEN_LEN)
  throw new ArgumentException();
 
- sb.Append(", PublicKeyToken=");
+ vsb.Append(", PublicKeyToken=");
  if (pkt.Length == 0)
- sb.Append("null");
+ {
+ vsb.Append("null");
+ }
  else
  {
- sb.Append(HexConverter.ToString(pkt, HexConverter.Casing.Lower));
+ HexConverter.EncodeToUtf16(pkt, vsb.AppendSpan(pkt.Length * 2), HexConverter.Casing.Lower);
  }
  }
 
  if (0 != (flags & AssemblyNameFlags.Retargetable))
- sb.Append(", Retargetable=Yes");
+ vsb.Append(", Retargetable=Yes");
 
  if (contentType == AssemblyContentType.WindowsRuntime)
- sb.Append(", ContentType=WindowsRuntime");
+ vsb.Append(", ContentType=WindowsRuntime");
 
  // NOTE: By design (desktop compat) AssemblyName.FullName and ToString() do not include ProcessorArchitecture.
 
- return sb.ToString();
+ return vsb.ToString();
  }
 
- private static void AppendQuoted(this StringBuilder sb, string s)
+ private static void AppendQuoted(this ref ValueStringBuilder vsb, string s)
  {
  bool needsQuoting = false;
  const char quoteChar = '\"';
@@ -90,7 +92,7 @@ private static void AppendQuoted(this StringBuilder sb, string s)
  needsQuoting = true;
 
  if (needsQuoting)
- sb.Append(quoteChar);
+ vsb.Append(quoteChar);
 
  for (int i = 0; i < s.Length; i++)
  {
@@ -101,24 +103,24 @@ private static void AppendQuoted(this StringBuilder sb, string s)
  case '=':
  case '\'':
  case '"':
- sb.Append('\\');
+ vsb.Append('\\');
  break;
  case '\t':
- sb.Append("\\t");
+ vsb.Append("\\t");
  continue;
  case '\r':
- sb.Append("\\r");
+ vsb.Append("\\r");
  continue;
  case '\n':
- sb.Append("\\n");
+ vsb.Append("\\n");
  continue;
  }
 
- sb.Append(s[i]);
+ vsb.Append(s[i]);
  }
 
  if (needsQuoting)
- sb.Append(quoteChar);
+ vsb.Append(quoteChar);
  }
 
  private static Version CanonicalizeVersion(this Version version)