Implemented TextFormatter

4 files changed, 475 insertions, 15 deletions

diff --git a/csharp/ProtocolBuffers/ByteString.cs b/csharp/ProtocolBuffers/ByteString.cs
index 94eb45e3..7c644f9a 100644
--- a/csharp/ProtocolBuffers/ByteString.cs
+++ b/csharp/ProtocolBuffers/ByteString.cs
@@ -15,13 +15,15 @@
 // limitations under the License.
 using System.Text;
 using System;
+using System.Collections.Generic;
+using System.Collections;
 
 namespace Google.ProtocolBuffers {
   /// <summary>
   /// Immutable array of bytes.
   /// TODO(jonskeet): Implement the common collection interfaces?
   /// </summary>
-  public sealed class ByteString {
+  public sealed class ByteString : IEnumerable<byte> {
 
     private static readonly ByteString empty = new ByteString(new byte[0]);
 
@@ -105,6 +107,14 @@ namespace Google.ProtocolBuffers {
       return ToString(Encoding.UTF8);
     }
 
+    public IEnumerator<byte> GetEnumerator() {
+      return ((IEnumerable<byte>) bytes).GetEnumerator();
+    }
+
+    IEnumerator IEnumerable.GetEnumerator() {
+      return GetEnumerator();
+    }
+
     /// <summary>
     /// Creates a CodedInputStream from this ByteString's data.
     /// </summary>
diff --git a/csharp/ProtocolBuffers/ProtocolBuffers.csproj b/csharp/ProtocolBuffers/ProtocolBuffers.csproj
index 706d2eaf..bcfe9f2f 100644
--- a/csharp/ProtocolBuffers/ProtocolBuffers.csproj
+++ b/csharp/ProtocolBuffers/ProtocolBuffers.csproj
@@ -87,6 +87,7 @@
     <Compile Include="InvalidProtocolBufferException.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="TextFormat.cs" />
+    <Compile Include="TextGenerator.cs" />
     <Compile Include="UninitializedMessageException.cs" />
     <Compile Include="UnknownField.cs" />
     <Compile Include="UnknownFieldSet.cs" />
diff --git a/csharp/ProtocolBuffers/TextFormat.cs b/csharp/ProtocolBuffers/TextFormat.cs
index 87c5e211..efa1ba94 100644
--- a/csharp/ProtocolBuffers/TextFormat.cs
+++ b/csharp/ProtocolBuffers/TextFormat.cs
@@ -1,35 +1,404 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Text;
+using Google.ProtocolBuffers.Descriptors;
+using System.Collections;
 
 namespace Google.ProtocolBuffers {
-  public class TextFormat {
+  /// <summary>
+  /// Provides ASCII text formatting support for messages.
+  /// TODO(jonskeet): Parsing support.
+  /// </summary>
+  public static class TextFormat {
+
+    /// <summary>
+    /// Outputs a textual representation of the Protocol Message supplied into
+    /// the parameter output.
+    /// </summary>
+    public static void Print(IMessage message, TextWriter output) {
+      TextGenerator generator = new TextGenerator(output);
+      Print(message, generator);
+    }
+
+    /// <summary>
+    /// Outputs a textual representation of <paramref name="fields" /> to <paramref name="output"/>.
+    /// </summary>
+    /// <param name="fields"></param>
+    /// <param name="output"></param>
+    public static void Print(UnknownFieldSet fields, TextWriter output) {
+      TextGenerator generator = new TextGenerator(output);
+      PrintUnknownFields(fields, generator);
+    }
+
     public static string PrintToString(IMessage message) {
-      throw new NotImplementedException();
+      StringWriter text = new StringWriter();
+      Print(message, text);
+      return text.ToString();
+    }
+
+    public static string PrintToString(UnknownFieldSet fields) {
+      StringWriter text = new StringWriter();
+      Print(fields, text);
+      return text.ToString();
+    }
+
+    private static void Print(IMessage message, TextGenerator generator) {
+      MessageDescriptor descriptor = message.DescriptorForType;
+      foreach (KeyValuePair<FieldDescriptor, object> entry in message.AllFields) {
+        PrintField(entry.Key, entry.Value, generator);
+      }
+      PrintUnknownFields(message.UnknownFields, generator);
+    }
+
+    internal static void PrintField(FieldDescriptor field, object value, TextGenerator generator) {
+      if (field.IsRepeated) {
+        // Repeated field.  Print each element.
+        foreach (object element in (IEnumerable) value) {
+          PrintSingleField(field, element, generator);
+        }
+      } else {
+        PrintSingleField(field, value, generator);
+      }
+    }
+
+    private static void PrintSingleField(FieldDescriptor field, Object value, TextGenerator generator) {
+      if (field.IsExtension) {
+        generator.Print("[");
+        // We special-case MessageSet elements for compatibility with proto1.
+        if (field.ContainingType.Options.MessageSetWireFormat
+            && field.FieldType == FieldType.Message
+            && field.IsOptional
+            // object equality (TODO(jonskeet): Work out what this comment means!)
+            && field.ExtensionScope == field.MessageType) {
+          generator.Print(field.MessageType.FullName);
+        } else {
+          generator.Print(field.FullName);
+        }
+        generator.Print("]");
+      } else {
+        if (field.FieldType == FieldType.Group) {
+          // Groups must be serialized with their original capitalization.
+          generator.Print(field.MessageType.Name);
+        } else {
+          generator.Print(field.Name);
+        }
+      }
+
+      if (field.MappedType == MappedType.Message) {
+        generator.Print(" {\n");
+        generator.Indent();
+      } else {
+        generator.Print(": ");
+      }
+
+      PrintFieldValue(field, value, generator);
+
+      if (field.MappedType == MappedType.Message) {
+        generator.Outdent();
+        generator.Print("}");
+      }
+      generator.Print("\n");
+    }
+
+    private static void PrintFieldValue(FieldDescriptor field, object value, TextGenerator generator) {
+      switch (field.FieldType) {
+        case FieldType.Int32:
+        case FieldType.Int64:
+        case FieldType.SInt32:
+        case FieldType.SInt64:
+        case FieldType.SFixed32:
+        case FieldType.SFixed64:
+        case FieldType.Float:
+        case FieldType.Double:
+        case FieldType.UInt32:
+        case FieldType.UInt64:
+        case FieldType.Fixed32:
+        case FieldType.Fixed64:
+          // Good old ToString() does what we want for these types. (Including the
+          // unsigned ones, unlike with Java.)
+          generator.Print(value.ToString());
+          break;
+        case FieldType.Bool:
+          // Explicitly use the Java true/false
+          generator.Print((bool) value ? "true" : "false");
+          break;
+
+        case FieldType.String:
+          generator.Print("\"");
+          generator.Print(EscapeText((string) value));
+          generator.Print("\"");
+          break;
+
+        case FieldType.Bytes: {
+          generator.Print("\"");
+          generator.Print(EscapeBytes((ByteString) value));
+          generator.Print("\"");
+          break;
+        }
+
+        case FieldType.Enum: {
+          generator.Print(((EnumValueDescriptor) value).Name);
+          break;
+        }
+
+        case FieldType.Message:
+        case FieldType.Group:
+          Print((IMessage) value, generator);
+          break;
+      }
     }
 
-    internal static string PrintToString(UnknownFieldSet unknownFieldSet) {
-      throw new NotImplementedException();
+    private static void PrintUnknownFields(UnknownFieldSet unknownFields, TextGenerator generator) {
+      foreach (KeyValuePair<int, UnknownField> entry in unknownFields.FieldDictionary) {
+        String prefix = entry.Key.ToString() + ": ";
+        UnknownField field = entry.Value;
+
+        foreach (ulong value in field.VarintList) {
+          generator.Print(entry.Key.ToString());
+          generator.Print(": ");
+          generator.Print(value.ToString());
+          generator.Print("\n");
+        }
+        foreach (uint value in field.Fixed32List) {
+          generator.Print(entry.Key.ToString());
+          generator.Print(": ");
+          // FIXME(jonskeet): Get format of this right; in Java it's %08x. Find out what this means
+          // Also check we're okay in terms of signed/unsigned.
+          generator.Print(string.Format("0x{0:x}", value));
+          generator.Print("\n");
+        }
+        foreach (ulong value in field.Fixed64List) {
+          generator.Print(entry.Key.ToString());
+          generator.Print(": ");
+          // FIXME(jonskeet): Get format of this right; in Java it's %016x. Find out what this means
+          // Also check we're okay in terms of signed/unsigned.
+          generator.Print(string.Format("0x{0:x}", value));
+          generator.Print("\n");
+        }
+        foreach (ByteString value in field.LengthDelimitedList) {
+          generator.Print(entry.Key.ToString());
+          generator.Print(": \"");
+          generator.Print(EscapeBytes(value));
+          generator.Print("\"\n");
+        }
+        foreach (UnknownFieldSet value in field.GroupList) {
+          generator.Print(entry.Key.ToString());
+          generator.Print(" {\n");
+          generator.Indent();
+          PrintUnknownFields(value, generator);
+          generator.Outdent();
+          generator.Print("}\n");
+        }
+      }
     }
 
-    internal static object ParseUInt64(string p) {
-      throw new NotImplementedException();
+
+    internal static ulong ParseUInt64(string text) {
+      return (ulong) ParseInteger(text, true, false);
     }
 
-    internal static object ParseInt64(string p) {
-      throw new NotImplementedException();
+    internal static long ParseInt64(string text) {
+      return ParseInteger(text, true, false);
     }
 
-    internal static object ParseUInt32(string p) {
-      throw new NotImplementedException();
+    internal static uint ParseUInt32(string text) {
+      return (uint) ParseInteger(text, true, false);
     }
 
-    internal static object ParseInt32(string p) {
-      throw new NotImplementedException();
+    internal static int ParseInt32(string text) {
+      return (int) ParseInteger(text, true, false);
     }
 
-    internal static object UnescapeBytes(string p) {
-      throw new NotImplementedException();
+    /// <summary>
+    /// Parses an integer in hex (leading 0x), decimal (no prefix) or octal (leading 0).
+    /// Only a negative sign is permitted, and it must come before the radix indicator.
+    /// </summary>
+    private static long ParseInteger(string text, bool isSigned, bool isLong) {
+      string original = text;
+      bool negative = false;
+      if (text.StartsWith("-")) {
+        if (!isSigned) {
+          throw new FormatException("Number must be positive: " + original);
+        }
+        negative = true;
+        text = text.Substring(1);
+      }
+
+      int radix = 10;
+      if (text.StartsWith("0x")) {
+        radix = 16;
+        text = text.Substring(2);
+      } else if (text.StartsWith("0")) {
+        radix = 8;
+        text = text.Substring(1);
+      }
+
+      ulong result = Convert.ToUInt64(text, radix);
+
+      if (negative) {
+        ulong max = isLong ? 0x8000000UL : 0x8000L;
+        if (result > max) {
+          throw new FormatException("Number of out range: " + original);
+        }
+        return -((long) result);
+      } else {
+        ulong max = isSigned 
+            ? (isLong ? (ulong) long.MaxValue : int.MaxValue)
+            : (isLong ? ulong.MaxValue : uint.MaxValue);
+        if (result > max) {
+          throw new FormatException("Number of out range: " + original);
+        }
+        return (long) result;
+      }
+    }
+
+    /// <summary>
+    /// Tests a character to see if it's an octal digit.
+    /// </summary>
+    private static bool IsOctal(char c) {
+      return '0' <= c && c <= '7';
+    }
+
+    /// <summary>
+    /// Tests a character to see if it's a hex digit.
+    /// </summary>
+    private static bool IsHex(char c) {
+      return ('0' <= c && c <= '9') ||
+             ('a' <= c && c <= 'f') ||
+             ('A' <= c && c <= 'F');
+    }
+
+    /// <summary>
+    /// Interprets a character as a digit (in any base up to 36) and returns the
+    /// numeric value.
+    /// </summary>
+    private static int ParseDigit(char c) {
+      if ('0' <= c && c <= '9') {
+        return c - '0';
+      } else if ('a' <= c && c <= 'z') {
+        return c - 'a' + 10;
+      } else {
+        return c - 'A' + 10;
+      }
+    }
+
+    /// <summary>
+    /// Like <see cref="EscapeBytes" /> but escapes a text string.
+    /// The string is first encoded as UTF-8, then each byte escaped individually.
+    /// The returned value is guaranteed to be entirely ASCII.
+    /// </summary>
+    static String EscapeText(string input) {
+      return EscapeBytes(ByteString.CopyFromUtf8(input));
+    }
+    /// <summary>
+    /// Escapes bytes in the format used in protocol buffer text format, which
+    /// is the same as the format used for C string literals.  All bytes
+    /// that are not printable 7-bit ASCII characters are escaped, as well as
+    /// backslash, single-quote, and double-quote characters.  Characters for
+    /// which no defined short-hand escape sequence is defined will be escaped
+    /// using 3-digit octal sequences.
+    /// The returned value is guaranteed to be entirely ASCII.
+    /// </summary>
+    private static String EscapeBytes(ByteString input) {
+      StringBuilder builder = new StringBuilder(input.Length);
+      foreach (byte b in input) {
+        switch (b) {
+          // C# does not use \a or \v
+          case 0x07: builder.Append("\\a" ); break;
+          case (byte)'\b': builder.Append("\\b" ); break;
+          case (byte)'\f': builder.Append("\\f" ); break;
+          case (byte)'\n': builder.Append("\\n" ); break;
+          case (byte)'\r': builder.Append("\\r" ); break;
+          case (byte)'\t': builder.Append("\\t" ); break;
+          case 0x0b: builder.Append("\\v" ); break;
+          case (byte)'\\': builder.Append("\\\\"); break;
+          case (byte)'\'': builder.Append("\\\'"); break;
+          case (byte)'"' : builder.Append("\\\""); break;
+          default:
+            if (b >= 0x20) {
+              builder.Append((char) b);
+            } else {
+              builder.Append('\\');
+              builder.Append((char) ('0' + ((b >> 6) & 3)));
+              builder.Append((char) ('0' + ((b >> 3) & 7)));
+              builder.Append((char) ('0' + (b & 7)));
+            }
+            break;
+        }
+      }
+      return builder.ToString();
+    }
+
+    /// <summary>
+    /// Performs string unescaping from C style (octal, hex, form feeds, tab etc) into a byte string.
+    /// </summary>
+    internal static ByteString UnescapeBytes(string input) {
+      byte[] result = new byte[input.Length];
+      int pos = 0;
+      for (int i = 0; i < input.Length; i++) {
+        char c = input[i];
+        if (c > 127 || c < 32) {
+          throw new FormatException("Escaped string must only contain ASCII");
+        }
+        if (c != '\\') {
+          result[pos++] = (byte) c;
+          continue;
+        }
+        if (i + 1 >= input.Length) {
+          throw new FormatException("Invalid escape sequence: '\\' at end of string.");
+        }
+
+        i++;
+        c = input[i];
+        if (c >= '0' && c <= '7') {
+          // Octal escape. 
+          int code = ParseDigit(c);
+          if (i + 1 < input.Length && IsOctal(input[i+1])) {
+            i++;
+            code = code * 8 + ParseDigit(input[i]);
+          }
+          if (i + 1 < input.Length && IsOctal(input[i+1])) {
+            i++;
+            code = code * 8 + ParseDigit(input[i]);
+          }
+          result[pos++] = (byte) code;
+        } else {
+          switch (c) {
+            case 'a': result[pos++] = 0x07; break;
+            case 'b': result[pos++] = (byte) '\b'; break;
+            case 'f': result[pos++] = (byte) '\f'; break;
+            case 'n': result[pos++] = (byte) '\n'; break;
+            case 'r': result[pos++] = (byte) '\r'; break;
+            case 't': result[pos++] = (byte) '\t'; break;
+            case 'v': result[pos++] = 0x0b; break;
+            case '\\': result[pos++] = (byte) '\\'; break;
+            case '\'': result[pos++] = (byte) '\''; break;
+            case '"': result[pos++] = (byte) '\"'; break;
+
+            case 'x':
+              // hex escape
+              int code;
+              if (i + 1 < input.Length && IsHex(input[i+1])) {
+                i++;
+                code = ParseDigit(input[i]);
+              } else {
+                throw new FormatException("Invalid escape sequence: '\\x' with no digits");
+              }
+              if (i + 1 < input.Length && IsHex(input[i+1])) {
+                ++i;
+                code = code * 16 + ParseDigit(input[i]);
+              }
+              result[pos++] = (byte)code;
+              break;
+
+            default:
+              throw new FormatException("Invalid escape sequence: '\\" + c + "'");
+          }
+        }
+      }
+
+      return ByteString.CopyFrom(result, 0, pos);
     }
   }
 }
diff --git a/csharp/ProtocolBuffers/TextGenerator.cs b/csharp/ProtocolBuffers/TextGenerator.cs
new file mode 100644
index 00000000..724c1a8f
--- /dev/null
+++ b/csharp/ProtocolBuffers/TextGenerator.cs
@@ -0,0 +1,80 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+
+namespace Google.ProtocolBuffers {
+
+  /// <summary>
+  /// Helper class to control indentation
+  /// </summary>
+  internal class TextGenerator {
+
+    /// <summary>
+    /// Writer to write formatted text to.
+    /// </summary>
+    private readonly TextWriter writer;
+
+    /// <summary>
+    /// Keeps track of whether the next piece of text should be indented
+    /// </summary>
+    bool atStartOfLine = true;
+
+    /// <summary>
+    /// Keeps track of the current level of indentation
+    /// </summary>
+    readonly StringBuilder indent = new StringBuilder();
+
+    /// <summary>
+    /// Creates a generator writing to the given writer.
+    /// </summary>
+    internal TextGenerator(TextWriter writer) {
+      this.writer = writer;
+    }
+
+    /// <summary>
+    /// Indents text by two spaces. After calling Indent(), two spaces
+    /// will be inserted at the beginning of each line of text. Indent() may
+    /// be called multiple times to produce deeper indents.
+    /// </summary>
+    internal void Indent() {
+      indent.Append("  ");
+    }
+
+    /// <summary>
+    /// Reduces the current indent level by two spaces.
+    /// </summary>
+    internal void Outdent() {
+      if (indent.Length == 0) {
+        throw new InvalidOperationException("Too many calls to Outdent()");
+      }
+      indent.Length -= 2;
+    }
+
+    /// <summary>
+    /// Prints the given text to the output stream, indenting at line boundaries.
+    /// </summary>
+    /// <param name="text"></param>
+    public void Print(string text) {
+      int pos = 0;
+
+      for (int i = 0; i < text.Length; i++) {
+        if (text[i] == '\n') {
+          // TODO(jonskeet): Use Environment.NewLine?
+          Write(text.Substring(pos, i - pos + 1));
+          pos = i + 1;
+          atStartOfLine = true;
+        }
+      }
+      Write(text.Substring(pos));
+    }
+
+    private void Write(string data) {
+      if (atStartOfLine) {
+        atStartOfLine = false;
+        writer.Write(indent);
+      }
+      writer.Write(data);
+    }
+  }
+}