[C++] Reduce copying of data in CppGenerator.

Author: mjpt777

sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/cpp/CppGenerator.java

@@ -132,13 +132,13 @@ public void generate() throws IOException
  collectVarData(messageBody, i, varData);
 
  final StringBuilder sb = new StringBuilder();
- out.append(generateFields(className, fields, BASE_INDENT, false));
+ generateFields(sb, className, fields, BASE_INDENT, false);
  generateGroups(sb, groups, BASE_INDENT);
+ generateVarData(sb, className, varData, BASE_INDENT);
+ generateDisplay(sb, msgToken.name(), fields, groups, varData, BASE_INDENT + INDENT);
+ sb.append("};\n");
+ sb.append(CppUtil.closingBraces(ir.namespaces().length)).append("#endif\n");
  out.append(sb);
- out.append(generateVarData(className, varData, BASE_INDENT));
- out.append(generateDisplay(msgToken.name(), fields, groups, varData, BASE_INDENT + INDENT));
- out.append("};\n");
- out.append(CppUtil.closingBraces(ir.namespaces().length)).append("#endif\n");
  }
  }
  }
@@ -165,20 +165,20 @@ private void generateGroups(final StringBuilder sb, final List<Token> tokens, fi
 
  final List<Token> fields = new ArrayList<>();
  i = collectFields(tokens, i, fields);
- sb.append(generateFields(formatClassName(groupName), fields, indent + INDENT, false));
+ generateFields(sb, formatClassName(groupName), fields, indent + INDENT, false);
 
  final List<Token> groups = new ArrayList<>();
  i = collectGroups(tokens, i, groups);
  generateGroups(sb, groups, indent + INDENT);
 
  final List<Token> varData = new ArrayList<>();
  i = collectVarData(tokens, i, varData);
- sb.append(generateVarData(formatClassName(groupName), varData, indent + INDENT));
+ generateVarData(sb, formatClassName(groupName), varData, indent + INDENT);
 
  sb.append(generateGroupDisplay(groupName, fields, groups, varData, indent + INDENT + INDENT));
 
  sb.append(indent).append(" };\n");
- sb.append(generateGroupProperty(groupName, groupToken, cppTypeForNumInGroup, indent));
+ generateGroupProperty(sb, groupName, groupToken, cppTypeForNumInGroup, indent);
  }
  }
 
@@ -350,11 +350,13 @@ private static void generateGroupClassHeader(
  .append(indent).append("#endif\n");
  }
 
- private static CharSequence generateGroupProperty(
- final String groupName, final Token token, final String cppTypeForNumInGroup, final String indent)
+ private static void generateGroupProperty(
+ final StringBuilder sb,
+ final String groupName,
+ final Token token,
+ final String cppTypeForNumInGroup,
+ final String indent)
  {
- final StringBuilder sb = new StringBuilder();
-
  final String className = formatClassName(groupName);
  final String propertyName = formatPropertyName(groupName);
 
@@ -413,14 +415,11 @@ private static CharSequence generateGroupProperty(
  indent + " }\n",
  propertyName,
  token.version()));
-
- return sb;
  }
 
- private CharSequence generateVarData(final String className, final List<Token> tokens, final String indent)
+ private void generateVarData(
+ final StringBuilder sb, final String className, final List<Token> tokens, final String indent)
  {
- final StringBuilder sb = new StringBuilder();
-
  for (int i = 0, size = tokens.size(); i < size;)
  {
  final Token token = tokens.get(i);
@@ -604,8 +603,6 @@ private CharSequence generateVarData(final String className, final List<Token> t
 
  i += token.componentTokenCount();
  }
-
- return sb;
  }
 
  private void generateVarDataDescriptors(
@@ -1979,11 +1976,13 @@ private CharSequence generateMessageFlyweightCode(final String className, final
  generateConstructorsAndOperators(className));
  }
 
- private CharSequence generateFields(
- final String containingClassName, final List<Token> tokens, final String indent, final boolean inComposite)
+ private void generateFields(
+ final StringBuilder sb,
+ final String containingClassName,
+ final List<Token> tokens,
+ final String indent,
+ final boolean inComposite)
  {
- final StringBuilder sb = new StringBuilder();
-
  for (int i = 0, size = tokens.size(); i < size; i++)
  {
  final Token signalToken = tokens.get(i);
@@ -2016,8 +2015,6 @@ private CharSequence generateFields(
  }
  }
  }
-
- return sb;
  }
 
  private void generateFieldCommonMethods(
@@ -2339,14 +2336,15 @@ private CharSequence generateLiteral(final PrimitiveType type, final String valu
  return literal;
  }
 
- private CharSequence generateDisplay(
+ private void generateDisplay(
+ final StringBuilder sb,
  final String name,
  final List<Token> fields,
  final List<Token> groups,
  final List<Token> varData,
  final String indent)
  {
- return String.format("\n" +
+ sb.append(String.format("\n" +
  indent + "template<typename CharT, typename Traits>\n" +
  indent + "friend std::basic_ostream<CharT, Traits>& operator<<(\n" +
  indent + " std::basic_ostream<CharT, Traits>& builder, %1$s _writer)\n" +
@@ -2363,7 +2361,7 @@ private CharSequence generateDisplay(
  indent + " return builder;\n" +
  indent + "}\n",
  formatClassName(name),
- appendDisplay(fields, groups, varData, indent + INDENT));
+ appendDisplay(fields, groups, varData, indent + INDENT)));
  }
 
  private CharSequence generateGroupDisplay(
@@ -2387,10 +2385,7 @@ private CharSequence generateGroupDisplay(
  appendDisplay(fields, groups, varData, indent + INDENT));
  }
 
- private CharSequence generateCompositeDisplay(
- final String name,
- final List<Token> tokens,
- final String indent)
+ private CharSequence generateCompositeDisplay(final String name, final List<Token> tokens, final String indent)
  {
  return String.format("\n" +
  indent + "template<typename CharT, typename Traits>\n" +
@@ -2407,10 +2402,7 @@ private CharSequence generateCompositeDisplay(
  }
 
  private CharSequence appendDisplay(
- final List<Token> fields,
- final List<Token> groups,
- final List<Token> varData,
- final String indent)
+ final List<Token> fields, final List<Token> groups, final List<Token> varData, final String indent)
  {
  final StringBuilder sb = new StringBuilder();
  final boolean[] atLeastOne = {false};