[C++] Escape var data character strings when pretty printing codecs as JSON. Issue aeron-io#718.

Author: mjpt777

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

@@ -302,6 +302,11 @@ private static void generateGroupClassHeader(
  indent + " *m_positionPtr = sbeCheckPosition(position);\n" +
  indent + " }\n\n" +
 
+ indent + " SBE_NODISCARD std::string sbeEscapeJson(const std::string &s) const SBE_NOEXCEPT\n" +
+ indent + " {\n" +
+ indent + " return ::sbeEscapeJsonString(s);\n" +
+ indent + " }\n\n" +
+
  indent + " SBE_NODISCARD inline std::uint64_t count() const SBE_NOEXCEPT\n" +
  indent + " {\n" +
  indent + " return m_count;\n" +
@@ -1010,7 +1015,9 @@ private static CharSequence generateFileHeader(
  "#include <cstring>\n" +
  "#include <limits>\n" +
  "#include <stdexcept>\n\n" +
- "#include <ostream>\n\n" +
+ "#include <ostream>\n" +
+ "#include <sstream>\n" +
+ "#include <iomanip>\n\n" +
 
  "#if defined(WIN32) || defined(_WIN32)\n" +
  "# define SBE_BIG_ENDIAN_ENCODE_16(v) _byteswap_ushort(v)\n" +
@@ -1053,10 +1060,12 @@ private static CharSequence generateFileHeader(
  "#define SBE_NULLVALUE_UINT8 (std::numeric_limits<std::uint8_t>::max)()\n" +
  "#define SBE_NULLVALUE_UINT16 (std::numeric_limits<std::uint16_t>::max)()\n" +
  "#define SBE_NULLVALUE_UINT32 (std::numeric_limits<std::uint32_t>::max)()\n" +
- "#define SBE_NULLVALUE_UINT64 (std::numeric_limits<std::uint64_t>::max)()\n",
+ "#define SBE_NULLVALUE_UINT64 (std::numeric_limits<std::uint64_t>::max)()\n\n",
  String.join("_", namespaces).toUpperCase(),
  className.toUpperCase()));
 
+ sb.append(generateEscapeFunction());
+
  if (typesToInclude != null && typesToInclude.size() != 0)
  {
  sb.append("\n");
@@ -1073,12 +1082,35 @@ private static CharSequence generateFileHeader(
  return sb;
  }
 
+ private static CharSequence generateEscapeFunction()
+ {
+ return
+ "#ifndef _SBE_JSON_ESCAPE_FUNC_H_\n" +
+ "#define _SBE_JSON_ESCAPE_FUNC_H_\n" +
+ "static inline std::string sbeEscapeJsonString(const std::string &s)\n" +
+ "{\n" +
+ " std::ostringstream oss;\n\n" +
+ " for (auto c = s.cbegin(); c != s.cend(); c++)\n" +
+ " {\n" +
+ " if (*c == '\"' || *c == '\\\\' || ('\\x00' <= *c && *c <= '\\x1f'))\n" +
+ " {\n" +
+ " oss << \"\\\\u\"" + " << std::hex << std::setw(4) << std::setfill('0') << (int)*c;\n" +
+ " }\n" +
+ " else\n" +
+ " {\n" +
+ " oss << *c;\n" +
+ " }\n" +
+ " }\n\n" +
+ " return oss.str();\n" +
+ "}\n" +
+ "#endif\n\n";
+ }
+
  private static CharSequence generateClassDeclaration(final String className)
  {
- return String.format(
- "class %s\n" +
- "{\n",
- className);
+ return
+ "class " + className + "\n" +
+ "{\n";
  }
 
  private static CharSequence generateEnumDeclaration(final String name)
@@ -1903,6 +1935,11 @@ private CharSequence generateMessageFlyweightCode(final String className, final
  " m_position = sbeCheckPosition(position);\n" +
  " }\n\n" +
 
+ " SBE_NODISCARD std::string sbeEscapeJson(const std::string &s) const SBE_NOEXCEPT\n" +
+ " {\n" +
+ " return ::sbeEscapeJsonString(s);\n" +
+ " }\n\n" +
+
  " SBE_NODISCARD std::uint64_t encodedLength() const SBE_NOEXCEPT\n" +
  " {\n" +
  " return sbePosition() - m_offset;\n" +
@@ -2320,7 +2357,7 @@ private CharSequence generateDisplay(
  indent + " builder << writer.sbeTemplateId();\n" +
  indent + " builder << \", \";\n\n" +
  "%2$s" +
- indent + " builder << '}';\n" +
+ indent + " builder << '}';\n\n" +
  indent + " return builder;\n" +
  indent + "}\n",
  formatClassName(name),
@@ -2341,7 +2378,7 @@ private CharSequence generateGroupDisplay(
  indent + "{\n" +
  indent + " builder << '{';\n" +
  "%2$s" +
- indent + " builder << '}';\n" +
+ indent + " builder << '}';\n\n" +
  indent + " return builder;\n" +
  indent + "}\n",
  formatClassName(name),
@@ -2360,7 +2397,7 @@ private CharSequence generateCompositeDisplay(
  indent + "{\n" +
  indent + " builder << '{';\n" +
  "%2$s" +
- indent + " builder << '}';\n" +
+ indent + " builder << '}';\n\n" +
  indent + " return builder;\n" +
  indent + "}\n\n",
  formatClassName(name),
@@ -2453,20 +2490,25 @@ private CharSequence appendDisplay(
  atLeastOne[0] = true;
 
  final String characterEncoding = varData.get(i + 3).encoding().characterEncoding();
- final String getAsStringFunction = "get" + toUpperFirstChar(varDataToken.name()) + "AsString().c_str()";
  sb.append(indent + "builder << R\"(\"" + varDataToken.name() + "\": )\";\n");
 
  if (null == characterEncoding)
  {
+ final String getAsStringFunction =
+ "writer.get" + toUpperFirstChar(varDataToken.name()) + "AsString().c_str()";
+
  sb.append(
  indent + "builder << '\"' <<\n" +
- indent + INDENT + "writer." + getAsStringFunction + " << '\"';\n\n");
+ indent + INDENT + getAsStringFunction + " << '\"';\n\n");
  }
  else
  {
+ final String getAsStringFunction =
+ "writer.sbeEscapeJson(writer.get" + toUpperFirstChar(varDataToken.name()) + "AsString()).c_str()";
+
  sb.append(
  indent + "builder << '\"' <<\n" +
- indent + INDENT + "writer." + getAsStringFunction + " << '\"';\n\n");
+ indent + INDENT + getAsStringFunction + " << '\"';\n\n");
  }
 
  i += varDataToken.componentTokenCount();
@@ -2510,8 +2552,8 @@ private CharSequence writeTokenDisplay(
  {
  sb.append(
  indent + "builder << '\"';\n" +
- indent + "for (size_t i = 0;\n" +
- indent + " i < " + fieldName + "Length() && " + fieldName + "(i) > 0;\n" +
+ indent + "for (size_t i = 0, length = " + fieldName + "Length();\n" +
+ indent + " i < length && " + fieldName + "(i) > 0;\n" +
  indent + " i++)\n" +
  indent + "{\n" +
  indent + " builder << (char)" + fieldName + "(i);\n" +
@@ -2524,7 +2566,7 @@ private CharSequence writeTokenDisplay(
  indent + "builder << '[';\n" +
  indent + "if (" + fieldName + "Length() > 0)\n" +
  indent + "{\n" +
- indent + " for (size_t i = 0; i < " + fieldName + "Length(); i++)\n" +
+ indent + " for (size_t i = 0, length = " + fieldName + "Length(); i < length; i++)\n" +
  indent + " {\n" +
  indent + " if (i)\n" +
  indent + " {\n" +