Improve code quality (#825)

* Avoid encoding ASCII in more cases

* Make Space a const

* Use WriteWhiteSpace extension to eliminate possible virtual call

* Use ASCII when encoding constrained character subset

* Simplify pragmas

* Revert Whitespace rename

* Fix using statement order

* Remove obsolete serialization support on .NET

* Remove obsolete serialization support on .NET (part 2)

src/UglyToad.PdfPig.Core/PdfDocumentFormatException.cs

@@ -1,14 +1,18 @@
 namespace UglyToad.PdfPig.Core
 {
     using System;
+#if !NET
     using System.Runtime.Serialization;
+#endif
 
     /// <inheritdoc />
     /// <summary>
     /// This exception will be thrown where the contents of the PDF document do not match the specification in such a way that it
     /// renders the document unreadable.
     /// </summary>
+#if !NET
     [Serializable]
+#endif
     public class PdfDocumentFormatException : Exception
     {
         /// <inheritdoc />
@@ -29,11 +33,13 @@
         {
         }
 
+#if !NET
         /// <inheritdoc />
         protected PdfDocumentFormatException(
             SerializationInfo info,
             StreamingContext context) : base(info, context)
         {
         }
+#endif
     }
 }

src/UglyToad.PdfPig.Core/Polyfills/EncodingExtensions.cs

@@ -1,4 +1,4 @@
-#if NETFRAMEWORK || NETSTANDARD2_0
+#if !NET
 
 namespace System.Text;
 

src/UglyToad.PdfPig.Core/Polyfills/StreamExtensions.cs

@@ -1,4 +1,4 @@
-#if NETFRAMEWORK || NETSTANDARD2_0
+#if !NET
 
 namespace System.IO;
 

src/UglyToad.PdfPig.Fonts/CorruptCompressedDataException.cs

@@ -1,12 +1,16 @@
 namespace UglyToad.PdfPig.Fonts
 {
     using System;
+#if !NET
     using System.Runtime.Serialization;
+#endif
 
     /// <summary>
     /// Thrown when a PDF contains an invalid compressed data stream.
     /// </summary>
+#if !NET
     [Serializable]
+#endif
     public class CorruptCompressedDataException : Exception
     {
         /// <inheritdoc />
@@ -24,11 +28,13 @@
         {
         }
 
+#if !NET
         /// <inheritdoc />
         protected CorruptCompressedDataException(
             SerializationInfo info,
             StreamingContext context) : base(info, context)
         {
         }
+#endif
     }
 }

src/UglyToad.PdfPig.Fonts/Polyfills/EncodingExtensions.cs

@@ -1,4 +1,4 @@
-#if NETFRAMEWORK || NETSTANDARD2_0
+#if !NET
 
 namespace System.Text;
 

src/UglyToad.PdfPig.Fonts/Polyfills/StreamExtensions.cs

@@ -1,4 +1,4 @@
-#if NETFRAMEWORK || NETSTANDARD2_0
+#if !NET
 
 namespace System.IO;
 

src/UglyToad.PdfPig.Tokenization/NameTokenizer.cs

@@ -5,7 +5,7 @@
     using Core;
     using Tokens;
 
-#if NET8_0_OR_GREATER
+#if NET
     using System.Text.Unicode;
 #endif
 
@@ -13,7 +13,7 @@
     {
         static NameTokenizer()
         {
-#if NET6_0_OR_GREATER
+#if NET
             Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
 #endif
         }

src/UglyToad.PdfPig/Content/Page.cs

@@ -131,7 +131,7 @@
                 return string.Empty;
             }
 
-#if NET6_0_OR_GREATER
+#if NET
             int length = 0;
 
             for (var i = 0; i < content.Letters.Count; i++)

src/UglyToad.PdfPig/Content/Pages.cs

@@ -117,7 +117,7 @@
             pageFactoryCache.Add(type, pageFactory);
         }
 
-#if NET6_0_OR_GREATER
+#if NET
         internal void AddPageFactory<TPage, [System.Diagnostics.CodeAnalysis.DynamicallyAccessedMembers(System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.PublicConstructors)] TPageFactory>() where TPageFactory : IPageFactory<TPage>
 #else
         internal void AddPageFactory<TPage, TPageFactory>() where TPageFactory : IPageFactory<TPage>

src/UglyToad.PdfPig/Exceptions/PdfDocumentEncryptedException.cs

@@ -1,14 +1,18 @@
 namespace UglyToad.PdfPig.Exceptions
 {
     using System;
+#if !NET
     using System.Runtime.Serialization;
+#endif
     using Encryption;
 
     /// <inheritdoc />
     /// <summary>
     /// The document is encrypted and cannot be decrypted.
     /// </summary>
+#if !NET
     [Serializable]
+#endif
     public class PdfDocumentEncryptedException : Exception
     {
         internal EncryptionDictionary? Dictionary { get; }
@@ -38,11 +42,13 @@
             Dictionary = dictionary;
         }
 
+#if !NET
         /// <inheritdoc />
         protected PdfDocumentEncryptedException(
             SerializationInfo info,
             StreamingContext context) : base(info, context)
         {
         }
+#endif
     }
 }

src/UglyToad.PdfPig/Graphics/Colors/ColorSpaceDetails.cs

@@ -576,7 +576,7 @@
                 }
             }
 
-#if NET8_0_OR_GREATER
+#if NET
             return CollectionsMarshal.AsSpan(transformed);
 #else
             return transformed.ToArray();
@@ -745,7 +745,7 @@
                 }
             }
 
-#if NET8_0_OR_GREATER
+#if NET
             return CollectionsMarshal.AsSpan(transformed);
 #else
             return transformed.ToArray();

src/UglyToad.PdfPig/Graphics/Operations/OperationWriteHelper.cs

@@ -9,7 +9,7 @@
 
     internal static class OperationWriteHelper
     {
-        private const byte WhiteSpace = (byte)' ';
+        private const byte Whitespace = (byte)' ';
         private const byte NewLine = (byte)'\n';
 
         public static void WriteText(this Stream stream, string text, bool appendWhitespace = false)
@@ -36,13 +36,18 @@
 #endif
             if (appendWhitespace)
             {
-                stream.WriteByte(WhiteSpace);
+                stream.WriteByte(Whitespace);
             }
         }
 
-        public static void WriteText(this Stream stream, ReadOnlySpan<byte> asciiBytes)
+        public static void WriteText(this Stream stream, ReadOnlySpan<byte> asciiBytes, bool appendWhitespace = false)
         {
             stream.Write(asciiBytes);
+
+            if (appendWhitespace)
+            {
+                stream.WriteByte(Whitespace);
+            }
         }
 
         public static void WriteHex(this Stream stream, ReadOnlySpan<byte> bytes)
@@ -60,7 +65,7 @@
 
         public static void WriteWhiteSpace(this Stream stream)
         {
-            stream.WriteByte(WhiteSpace);
+            stream.WriteByte(Whitespace);
         }
 
         public static void WriteNewLine(this Stream stream)
@@ -80,7 +85,7 @@
         public static void WriteNumberText(this Stream stream, int number, string text)
         {
             stream.WriteDouble(number);
-            stream.WriteWhiteSpace();
+            stream.WriteByte(Whitespace);
             stream.WriteText(text);
             stream.WriteNewLine();
         }
@@ -88,7 +93,7 @@
         public static void WriteNumberText(this Stream stream, int number, ReadOnlySpan<byte> asciiBytes)
         {
             stream.WriteDouble(number);
-            stream.WriteWhiteSpace();
+            stream.WriteByte(Whitespace);
             stream.WriteText(asciiBytes);
             stream.WriteNewLine();
         }
@@ -96,7 +101,7 @@
         public static void WriteNumberText(this Stream stream, double number, string text)
         {
             stream.WriteDouble(number);
-            stream.WriteWhiteSpace();
+            stream.WriteByte(Whitespace);
             stream.WriteText(text);
             stream.WriteNewLine();
         }

src/UglyToad.PdfPig/IO/StreamWrapper.cs

@@ -27,7 +27,7 @@
             Stream.SetLength(value);
         }
 
-#if NET6_0_OR_GREATER
+#if NET
         public override int Read(Span<byte> buffer)
         {
             return Stream.Read(buffer);
@@ -44,7 +44,7 @@
             Stream.Write(buffer, offset, count);
         }
 
-#if NET6_0_OR_GREATER
+#if NET
         public override void Write(ReadOnlySpan<byte> buffer)
         {
             Stream.Write(buffer);

src/UglyToad.PdfPig/Images/Png/PngStreamWriteHelper.cs

@@ -53,7 +53,7 @@
             inner.Write(buffer, offset, count);
         }
 
-#if NET6_0_OR_GREATER
+#if NET
         public override void Write(ReadOnlySpan<byte> buffer)
         {
             crc.Append(buffer);

src/UglyToad.PdfPig/PdfDocument.cs

@@ -139,7 +139,7 @@
         /// </summary>
         /// <typeparam name="TPage"></typeparam>
         /// <typeparam name="TPageFactory"></typeparam>
-#if NET6_0_OR_GREATER
+#if NET
         public void AddPageFactory<TPage, [System.Diagnostics.CodeAnalysis.DynamicallyAccessedMembers(System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.PublicConstructors)] TPageFactory>() where TPageFactory : IPageFactory<TPage>
 #else
         public void AddPageFactory<TPage, TPageFactory>() where TPageFactory : IPageFactory<TPage>

src/UglyToad.PdfPig/Polyfills/NullableAnnotations.cs

@@ -5,7 +5,7 @@
 
 namespace System.Diagnostics.CodeAnalysis;
 
-#if NETSTANDARD2_0 || NETFRAMEWORK
+#if !NET
 internal sealed class DoesNotReturnAttribute : Attribute { }
 
 [AttributeUsage(AttributeTargets.Parameter, Inherited = false)]

src/UglyToad.PdfPig/Polyfills/StreamExtensions.cs

@@ -1,4 +1,4 @@
-#if NETFRAMEWORK || NETSTANDARD2_0
+#if !NET
 
 namespace System.IO;
 

src/UglyToad.PdfPig/Writer/Fonts/ToUnicodeCMapBuilder.cs

@@ -9,109 +9,98 @@
 
     internal static class ToUnicodeCMapBuilder
     {
-        private const string BeginToken = "begin";
+        private static ReadOnlySpan<byte> BeginToken => "begin"u8;
-        private const string BeginCMapToken = "begincmap";
+        private static ReadOnlySpan<byte> BeginCMapToken => "begincmap"u8;
-        private const string DefToken = "def";
+        private static ReadOnlySpan<byte> DefToken => "def"u8;
-        private const string DictToken = "dict";
+        private static ReadOnlySpan<byte> DictToken => "dict"u8;
-        private const string FindResourceToken = "findresource";
+        private static ReadOnlySpan<byte> FindResourceToken => "findresource"u8;
 
         private static readonly TokenWriter TokenWriter = new TokenWriter();
 
         public static byte[] ConvertToCMapStream(IReadOnlyDictionary<char, byte> unicodeToCharacterCode)
         {
-            using (var memoryStream = new MemoryStream())
+            using var memoryStream = new MemoryStream();
+
+            TokenWriter.WriteToken(NameToken.CidInit, memoryStream);
+            TokenWriter.WriteToken(NameToken.ProcSet, memoryStream);
+            memoryStream.WriteText(FindResourceToken, true);
+            memoryStream.WriteText(BeginToken);
+
+            memoryStream.WriteNewLine();
+
+            memoryStream.WriteDouble(12);
+            memoryStream.WriteWhiteSpace();
+            memoryStream.WriteText(DictToken, true);
+            memoryStream.WriteText(BeginToken);
+            memoryStream.WriteNewLine();
+
+            memoryStream.WriteText(BeginCMapToken);
+            memoryStream.WriteNewLine();
+
+            TokenWriter.WriteToken(NameToken.CidSystemInfo, memoryStream);
+
+            var dictionary = new DictionaryToken(new Dictionary<NameToken, IToken> {
+                { NameToken.Registry, new StringToken("Adobe") },
+                { NameToken.Ordering, new StringToken("UCS") },
+                { NameToken.Supplement, new NumericToken(0) }
+            });
+
+            TokenWriter.WriteToken(dictionary, memoryStream);
+            memoryStream.WriteWhiteSpace();
+
+            memoryStream.WriteText(DefToken);
+            memoryStream.WriteNewLine();
+
+            TokenWriter.WriteToken(NameToken.Cmapname, memoryStream);
+            TokenWriter.WriteToken(NameToken.Create("Adobe-Identity-UCS"), memoryStream);
+            memoryStream.WriteText(DefToken);
+
+            memoryStream.WriteNewLine();
+
+            TokenWriter.WriteToken(NameToken.CmapType, memoryStream);
+            memoryStream.WriteNumberText(2, DefToken);
+            memoryStream.WriteNumberText(1, "begincodespacerange"u8);
+
+            TokenWriter.WriteToken(new HexToken(['0', '0']), memoryStream);
+            TokenWriter.WriteToken(new HexToken(['F', 'F']), memoryStream);
+
+            memoryStream.WriteNewLine();
+
+            memoryStream.WriteText("endcodespacerange"u8);
+            memoryStream.WriteNewLine();
+
+            memoryStream.WriteNumberText(unicodeToCharacterCode.Count, "beginbfchar"u8);
+
+            foreach (var keyValuePair in unicodeToCharacterCode)
             {
-                TokenWriter.WriteToken(NameToken.CidInit, memoryStream);
+                var unicodeInt = (ushort)keyValuePair.Key;
-                TokenWriter.WriteToken(NameToken.ProcSet, memoryStream);
+                var low = (byte)(unicodeInt >> 0);
-                memoryStream.WriteText(FindResourceToken, true);
+                var high = (byte)(unicodeInt >> 8);
-                memoryStream.WriteText(BeginToken);
+                var from = Hex.GetString([keyValuePair.Value]);
+                var to = Hex.GetString([high, low]);
+
+                TokenWriter.WriteToken(new HexToken(from.AsSpan()), memoryStream);
+                TokenWriter.WriteToken(new HexToken(to.AsSpan()), memoryStream);
 
                 memoryStream.WriteNewLine();
-
-                memoryStream.WriteDouble(12);
-                memoryStream.WriteWhiteSpace();
-                memoryStream.WriteText(DictToken, true);
-                memoryStream.WriteText(BeginToken);
-
-                memoryStream.WriteNewLine();
-
-                memoryStream.WriteText(BeginCMapToken);
-
-                memoryStream.WriteNewLine();
-
-                TokenWriter.WriteToken(NameToken.CidSystemInfo, memoryStream);
-
-                var dictionary = new DictionaryToken(new Dictionary<NameToken, IToken>
-                {
-                    { NameToken.Registry, new StringToken("Adobe") },
-                    { NameToken.Ordering, new StringToken("UCS") },
-                    { NameToken.Supplement, new NumericToken(0) }
-                });
-
-                TokenWriter.WriteToken(dictionary, memoryStream);
-                memoryStream.WriteWhiteSpace();
-
-                memoryStream.WriteText(DefToken);
-
-                memoryStream.WriteNewLine();
-
-                TokenWriter.WriteToken(NameToken.Cmapname, memoryStream);
-                TokenWriter.WriteToken(NameToken.Create("Adobe-Identity-UCS"), memoryStream);
-                memoryStream.WriteText(DefToken);
-
-                memoryStream.WriteNewLine();
-
-                TokenWriter.WriteToken(NameToken.CmapType, memoryStream);
-                memoryStream.WriteNumberText(2, DefToken);
-                memoryStream.WriteNumberText(1, "begincodespacerange"u8);
-
-                TokenWriter.WriteToken(new HexToken(['0', '0']), memoryStream);
-                TokenWriter.WriteToken(new HexToken(['F', 'F']), memoryStream);
-
-                memoryStream.WriteNewLine();
-
-                memoryStream.WriteText("endcodespacerange"u8);
-
-                memoryStream.WriteNewLine();
-
-                memoryStream.WriteNumberText(unicodeToCharacterCode.Count, "beginbfchar"u8);
-                
-                foreach (var keyValuePair in unicodeToCharacterCode)
-                {
-                    var unicodeInt = (ushort) keyValuePair.Key;
-                    var low = (byte) (unicodeInt >> 0);
-                    var high = (byte) (unicodeInt >> 8);
-                    var from = Hex.GetString([keyValuePair.Value]);
-                    var to = Hex.GetString([high, low]);
-
-                    TokenWriter.WriteToken(new HexToken(from.AsSpan()), memoryStream);
-                    TokenWriter.WriteToken(new HexToken(to.AsSpan()), memoryStream);
-
-                    memoryStream.WriteNewLine();
-                }
-
-                memoryStream.WriteText("endbfchar"u8);
-
-                memoryStream.WriteNewLine();
-
-                memoryStream.WriteText("endcmap"u8);
-
-                memoryStream.WriteNewLine();
-
-                memoryStream.WriteText("CMapName currentdict /CMap defineresource pop"u8);
-
-                memoryStream.WriteNewLine();
-
-                memoryStream.WriteText("end"u8);
-
-                memoryStream.WriteNewLine();
-
-                memoryStream.WriteText("end"u8);
-
-                memoryStream.WriteNewLine();
-
-                return memoryStream.ToArray();
             }
+
+            memoryStream.WriteText("endbfchar"u8);
+            memoryStream.WriteNewLine();
+
+            memoryStream.WriteText("endcmap"u8);
+            memoryStream.WriteNewLine();
+
+            memoryStream.WriteText("CMapName currentdict /CMap defineresource pop"u8);
+            memoryStream.WriteNewLine();
+
+            memoryStream.WriteText("end"u8);
+            memoryStream.WriteNewLine();
+
+            memoryStream.WriteText("end"u8);
+            memoryStream.WriteNewLine();
+
+            return memoryStream.ToArray();
         }
     }
-}
+}

src/UglyToad.PdfPig/Writer/PdfStreamWriter.cs

@@ -1,11 +1,11 @@
 namespace UglyToad.PdfPig.Writer
 {
+    using Core;
+    using Graphics.Operations;
     using System;
     using System.Collections.Generic;
     using System.Globalization;
     using System.IO;
-    using Core;
-    using Graphics.Operations;
     using Tokens;
 
     /// <summary>
@@ -85,8 +85,8 @@
         {
             recordVersion?.Invoke(version);
 
-            WriteString($"%PDF-{version.ToString("0.0", CultureInfo.InvariantCulture)}", Stream);
+            Stream.WriteText($"%PDF-{version.ToString("0.0", CultureInfo.InvariantCulture)}");
-
+            Stream.WriteNewLine();
             Stream.WriteText("%"u8);
             Stream.Write([169, 205, 196, 210]);
             Stream.WriteNewLine();
@@ -98,12 +98,6 @@
             TokenWriter.WriteCrossReferenceTable(offsets, catalogReference.Data, Stream, documentInformationReference?.Data);
         }
 
-        private static void WriteString(string text, Stream stream)
-        {
-            var bytes = OtherEncodings.StringAsLatin1Bytes(text);
-            stream.Write(bytes, 0, bytes.Length);
-            stream.WriteNewLine();
-        }
 
         public void Dispose()
         {

src/UglyToad.PdfPig/Writer/TokenWriter.cs

@@ -64,7 +64,7 @@
 
         private static ReadOnlySpan<byte> TrueBytes => "true"u8;
 
-        private static readonly byte Whitespace = (byte)' ';
+        private const byte Whitespace = (byte)' ';
 
         private static ReadOnlySpan<byte> Xref => "xref"u8;
 
@@ -219,12 +219,11 @@
                      * n is a literal keyword identifying this as an in-use entry
                      * eol is a 2-character end-of-line sequence ('\r\n' or ' \n')
                      */
-                        var paddedOffset = OtherEncodings.StringAsLatin1Bytes(offset.Offset.ToString("D10", CultureInfo.InvariantCulture));
+                        var paddedOffset = Encoding.ASCII.GetBytes(offset.Offset.ToString("D10", CultureInfo.InvariantCulture));
                         outputStream.Write(paddedOffset);
+                        outputStream.WriteWhiteSpace();
 
-                        WriteWhitespace(outputStream);
+                        var generation = Encoding.ASCII.GetBytes(offset.Generation.ToString("D5", CultureInfo.InvariantCulture));
-
-                        var generation = OtherEncodings.StringAsLatin1Bytes(offset.Generation.ToString("D5", CultureInfo.InvariantCulture));
                         outputStream.Write(generation);
 
                         WriteWhitespace(outputStream);
@@ -289,10 +288,10 @@
         public void WriteObject(long objectNumber, int generation, byte[] data, Stream outputStream)
         {
             WriteLong(objectNumber, outputStream);
-            WriteWhitespace(outputStream);
+            outputStream.WriteWhiteSpace();
 
             WriteInt(generation, outputStream);
-            WriteWhitespace(outputStream);
+            outputStream.WriteWhiteSpace();
 
             outputStream.Write(ObjStart);
             WriteLineBreak(outputStream);
@@ -321,7 +320,7 @@
         protected void WriteArray(ArrayToken array, Stream outputStream)
         {
             outputStream.WriteByte(ArrayStart);
-            WriteWhitespace(outputStream);
+            outputStream.WriteWhiteSpace();
 
             for (var i = 0; i < array.Data.Count; i++)
             {
@@ -330,7 +329,7 @@
             }
 
             outputStream.WriteByte(ArrayEnd);
-            WriteWhitespace(outputStream);
+            outputStream.WriteWhiteSpace();
         }
 
         /// <summary>
@@ -340,7 +339,7 @@
         {
             var bytes = boolean.Data ? TrueBytes : FalseBytes;
             outputStream.Write(bytes);
-            WriteWhitespace(outputStream);
+            outputStream.WriteWhiteSpace();
         }
 
         /// <summary>
@@ -348,9 +347,8 @@
         /// </summary>
         protected void WriteComment(CommentToken comment, Stream outputStream)
         {
-            var bytes = OtherEncodings.StringAsLatin1Bytes(comment.Data);
             outputStream.WriteByte(Comment);
-            outputStream.Write(bytes);
+            outputStream.WriteText(comment.Data);
             WriteLineBreak(outputStream);
         }
 
@@ -360,7 +358,7 @@
         protected void WriteNullToken(Stream outputStream)
         {
             outputStream.Write("null"u8);
-            WriteWhitespace(outputStream);
+            outputStream.WriteWhiteSpace();
         }
 
         /// <summary>
@@ -398,13 +396,13 @@
         protected virtual void WriteIndirectReference(IndirectReferenceToken reference, Stream outputStream)
         {
             WriteLong(reference.Data.ObjectNumber, outputStream);
-            WriteWhitespace(outputStream);
+            outputStream.WriteWhiteSpace();
 
             WriteInt(reference.Data.Generation, outputStream);
-            WriteWhitespace(outputStream);
+            outputStream.WriteWhiteSpace();
 
             outputStream.WriteByte(RByte);
-            WriteWhitespace(outputStream);
+            outputStream.WriteWhiteSpace();
         }
 
         /// <summary>
@@ -447,7 +445,7 @@
 
             outputStream.WriteByte(NameStart);
             outputStream.Write(sb.WrittenSpan);
-            WriteWhitespace(outputStream);
+            outputStream.WriteWhiteSpace();
         }
 
         /// <summary>
@@ -484,10 +482,10 @@
         protected virtual void WriteObject(ObjectToken objectToken, Stream outputStream)
         {
             WriteLong(objectToken.Number.ObjectNumber, outputStream);
-            WriteWhitespace(outputStream);
+            outputStream.WriteWhiteSpace();
 
             WriteInt(objectToken.Number.Generation, outputStream);
-            WriteWhitespace(outputStream);
+            outputStream.WriteWhiteSpace();
 
             outputStream.Write(ObjStart);
             WriteLineBreak(outputStream);
@@ -590,7 +588,7 @@
             }
 
             outputStream.WriteByte(StringEnd);
-            WriteWhitespace(outputStream);
+            outputStream.WriteWhiteSpace();
         }
 
         /// <summary>