Esempio n. 1
0
// Recusively generate struct construction statements of the form:
// builder.putType(name);
// and insert manual padding.
static void GenStructBody(const StructDef &struct_def, std::string *code_ptr,
                          const char *nameprefix) {
  std::string &code = *code_ptr;
  code += "    builder.prep(" + NumToString(struct_def.minalign) + ", 0);\n";
  for (auto it = struct_def.fields.vec.rbegin();
       it != struct_def.fields.vec.rend();
       ++it) {
    auto &field = **it;
    if (field.padding)
      code += "    builder.pad(" + NumToString(field.padding) + ");\n";
    if (IsStruct(field.value.type)) {
      GenStructBody(*field.value.type.struct_def, code_ptr,
                    (field.value.type.struct_def->name + "_").c_str());
    } else {
      code += "    builder.put" + GenMethod(field) + "(";
      code += nameprefix + MakeCamel(field.name, false) + ");\n";
    }
  }
}
Esempio n. 2
0
static void GenStruct(StructDef &struct_def,
                      std::string *code_ptr,
                      StructDef *root_struct_def) {
  if (struct_def.generated) return;
  std::string &code = *code_ptr;

  // Generate a struct accessor class, with methods of the form:
  // public type name() { return bb.getType(i + offset); }
  // or for tables of the form:
  // public type name() {
  //   int o = __offset(offset); return o != 0 ? bb.getType(o + i) : default;
  // }
  GenComment(struct_def.doc_comment, code_ptr);
  code += "public class " + struct_def.name + " extends ";
  code += struct_def.fixed ? "Struct" : "Table";
  code += " {\n";
  if (&struct_def == root_struct_def) {
    // Generate a special accessor for the table that has been declared as
    // the root type.
    code += "  public static " + struct_def.name + " getRootAs";
    code += struct_def.name;
    code += "(ByteBuffer _bb, int offset) { ";
    code += "_bb.order(ByteOrder.LITTLE_ENDIAN); ";
    code += "return (new " + struct_def.name;
    code += "()).__init(_bb.getInt(offset) + offset, _bb); }\n";
  }
  // Generate the __init method that sets the field in a pre-existing
  // accessor object. This is to allow object reuse.
  code += "  public " + struct_def.name;
  code += " __init(int _i, ByteBuffer _bb) ";
  code += "{ bb_pos = _i; bb = _bb; return this; }\n";
  for (auto it = struct_def.fields.vec.begin();
       it != struct_def.fields.vec.end();
       ++it) {
    auto &field = **it;
    if (field.deprecated) continue;
    GenComment(field.doc_comment, code_ptr, "  ");
    std::string type_name = GenTypeGet(field.value.type);
    std::string method_start = "  public " + type_name + " " +
                               MakeCamel(field.name, false);
    // Generate the accessors that don't do object reuse.
    if (field.value.type.base_type == BASE_TYPE_STRUCT) {
      // Calls the accessor that takes an accessor object with a new object.
      code += method_start + "() { return " + MakeCamel(field.name, false);
      code += "(new ";
      code += type_name + "()); }\n";
    } else if (field.value.type.base_type == BASE_TYPE_VECTOR &&
               field.value.type.element == BASE_TYPE_STRUCT) {
      // Accessors for vectors of structs also take accessor objects, this
      // generates a variant without that argument.
      code += method_start + "(int j) { return " + MakeCamel(field.name, false);
      code += "(new ";
      code += type_name + "(), j); }\n";
    }
    std::string getter = GenGetter(field.value.type);
    code += method_start + "(";
    // Most field accessors need to retrieve and test the field offset first,
    // this is the prefix code for that:
    auto offset_prefix = ") { int o = __offset(" +
                         NumToString(field.value.offset) +
                         "); return o != 0 ? ";
    if (IsScalar(field.value.type.base_type)) {
      if (struct_def.fixed) {
        code += ") { return " + getter;
        code += "(bb_pos + " + NumToString(field.value.offset) + ")";
      } else {
        code += offset_prefix + getter;
        code += "(o + bb_pos) : " + field.value.constant;
      }
    } else {
      switch (field.value.type.base_type) {
        case BASE_TYPE_STRUCT:
          code += type_name + " obj";
          if (struct_def.fixed) {
            code += ") { return obj.__init(bb_pos + ";
            code += NumToString(field.value.offset) + ", bb)";
          } else {
            code += offset_prefix;
            code += "obj.__init(";
            code += field.value.type.struct_def->fixed
                      ? "o + bb_pos"
                      : "__indirect(o + bb_pos)";
            code += ", bb) : null";
          }
          break;
        case BASE_TYPE_STRING:
          code += offset_prefix + getter +"(o) : null";
          break;
        case BASE_TYPE_VECTOR: {
          auto vectortype = field.value.type.VectorType();
          if (vectortype.base_type == BASE_TYPE_STRUCT) {
            code += type_name + " obj, ";
            getter = "obj.__init";
          }
          code += "int j" + offset_prefix + getter +"(";
          auto index = "__vector(o) + j * " +
                       NumToString(InlineSize(vectortype));
          if (vectortype.base_type == BASE_TYPE_STRUCT) {
            code += vectortype.struct_def->fixed
                      ? index
                      : "__indirect(" + index + ")";
            code += ", bb";
          } else {
            code += index;
          }
          code += ") : ";
          code += IsScalar(field.value.type.element) ? "0" : "null";
          break;
        }
        case BASE_TYPE_UNION:
          code += type_name + " obj" + offset_prefix + getter;
          code += "(obj, o) : null";
          break;
        default:
          assert(0);
      }
    }
    code += "; }\n";
    if (field.value.type.base_type == BASE_TYPE_VECTOR) {
      code += "  public int " + MakeCamel(field.name, false) + "Length(";
      code += offset_prefix;
      code += "__vector_len(o) : 0; }\n";
    }
  }
  code += "\n";
  if (struct_def.fixed) {
    // create a struct constructor function
    code += "  public static int create" + struct_def.name;
    code += "(FlatBufferBuilder builder";
    GenStructArgs(struct_def, code_ptr, "");
    code += ") {\n";
    GenStructBody(struct_def, code_ptr, "");
    code += "    return builder.offset();\n  }\n";
  } else {
    // Create a set of static methods that allow table construction,
    // of the form:
    // public static void addName(FlatBufferBuilder builder, short name)
    // { builder.addShort(id, name, default); }
    code += "  public static void start" + struct_def.name;
    code += "(FlatBufferBuilder builder) { builder.startObject(";
    code += NumToString(struct_def.fields.vec.size()) + "); }\n";
    for (auto it = struct_def.fields.vec.begin();
         it != struct_def.fields.vec.end();
         ++it) {
      auto &field = **it;
      if (field.deprecated) continue;
      code += "  public static void add" + MakeCamel(field.name);
      code += "(FlatBufferBuilder builder, " + GenTypeBasic(field.value.type);
      auto argname = MakeCamel(field.name, false);
      if (!IsScalar(field.value.type.base_type)) argname += "Offset";
      code += " " + argname + ") { builder.add";
      code += GenMethod(field) + "(";
      code += NumToString(it - struct_def.fields.vec.begin()) + ", ";
      code += argname + ", " + field.value.constant;
      code += "); }\n";
      if (field.value.type.base_type == BASE_TYPE_VECTOR) {
        code += "  public static void start" + MakeCamel(field.name);
        code += "Vector(FlatBufferBuilder builder, int numElems) ";
        code += "{ builder.startVector(";
        code += NumToString(InlineSize(field.value.type.VectorType()));
        code += ", numElems); }\n";
      }
    }
    code += "  public static int end" + struct_def.name;
    code += "(FlatBufferBuilder builder) { return builder.endObject(); }\n";
  }
  code += "};\n\n";
}