diff options
Diffstat (limited to 'src/idl_gen_java.cpp')
| -rw-r--r-- | src/idl_gen_java.cpp | 1237 |
1 files changed, 1237 insertions, 0 deletions
diff --git a/src/idl_gen_java.cpp b/src/idl_gen_java.cpp new file mode 100644 index 00000000..9679a1aa --- /dev/null +++ b/src/idl_gen_java.cpp @@ -0,0 +1,1237 @@ +/* + * Copyright 2014 Google Inc. All rights reserved. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +// independent from idl_parser, since this code is not needed for most clients + +#include "flatbuffers/code_generators.h" +#include "flatbuffers/flatbuffers.h" +#include "flatbuffers/idl.h" +#include "flatbuffers/util.h" + +#if defined(FLATBUFFERS_CPP98_STL) +# include <cctype> +#endif // defined(FLATBUFFERS_CPP98_STL) + +namespace flatbuffers { +namespace java { + +static TypedFloatConstantGenerator JavaFloatGen("Double.", "Float.", "NaN", + "POSITIVE_INFINITY", + "NEGATIVE_INFINITY"); + +static CommentConfig comment_config = { + "/**", + " *", + " */", +}; + +class JavaGenerator : public BaseGenerator { + public: + JavaGenerator(const Parser &parser, const std::string &path, + const std::string &file_name) + : BaseGenerator(parser, path, file_name, "", ".", "java"), + cur_name_space_(nullptr) {} + + JavaGenerator &operator=(const JavaGenerator &); + bool generate() { + std::string one_file_code; + cur_name_space_ = parser_.current_namespace_; + + for (auto it = parser_.enums_.vec.begin(); it != parser_.enums_.vec.end(); + ++it) { + std::string enumcode; + auto &enum_def = **it; + if (!parser_.opts.one_file) cur_name_space_ = enum_def.defined_namespace; + GenEnum(enum_def, &enumcode); + if (parser_.opts.one_file) { + one_file_code += enumcode; + } else { + if (!SaveType(enum_def.name, *enum_def.defined_namespace, enumcode, + false)) + return false; + } + } + + for (auto it = parser_.structs_.vec.begin(); + it != parser_.structs_.vec.end(); ++it) { + std::string declcode; + auto &struct_def = **it; + if (!parser_.opts.one_file) + cur_name_space_ = struct_def.defined_namespace; + GenStruct(struct_def, &declcode); + if (parser_.opts.one_file) { + one_file_code += declcode; + } else { + if (!SaveType(struct_def.name, *struct_def.defined_namespace, declcode, + true)) + return false; + } + } + + if (parser_.opts.one_file) { + return SaveType(file_name_, *parser_.current_namespace_, one_file_code, + true); + } + return true; + } + + // Save out the generated code for a single class while adding + // declaration boilerplate. + bool SaveType(const std::string &defname, const Namespace &ns, + const std::string &classcode, bool needs_includes) const { + if (!classcode.length()) return true; + + std::string code; + code = "// " + std::string(FlatBuffersGeneratedWarning()) + "\n\n"; + + std::string namespace_name = FullNamespace(".", ns); + if (!namespace_name.empty()) { + code += "package " + namespace_name + ";"; + code += "\n\n"; + } + if (needs_includes) { + code += + "import java.nio.*;\nimport java.lang.*;\nimport " + "java.util.*;\nimport com.google.flatbuffers.*;\n"; + if (parser_.opts.gen_nullable) { + code += "\nimport javax.annotation.Nullable;\n"; + } + if (parser_.opts.java_checkerframework) { + code += "\nimport org.checkerframework.dataflow.qual.Pure;\n"; + } + code += "\n@SuppressWarnings(\"unused\")\n"; + } + if (parser_.opts.gen_generated) { + code += "\n@javax.annotation.Generated(value=\"flatc\")\n"; + } + code += classcode; + if (!namespace_name.empty()) code += ""; + auto filename = NamespaceDir(ns) + defname + ".java"; + return SaveFile(filename.c_str(), code, false); + } + + const Namespace *CurrentNameSpace() const { return cur_name_space_; } + + std::string GenNullableAnnotation(const Type &t) const { + return parser_.opts.gen_nullable && + !IsScalar(DestinationType(t, true).base_type) && + t.base_type != BASE_TYPE_VECTOR + ? " @Nullable " + : ""; + } + + std::string GenPureAnnotation(const Type &t) const { + return parser_.opts.java_checkerframework && + !IsScalar(DestinationType(t, true).base_type) + ? " @Pure " + : ""; + } + + std::string GenTypeBasic(const Type &type) const { + // clang-format off + static const char * const java_typename[] = { + #define FLATBUFFERS_TD(ENUM, IDLTYPE, CTYPE, JTYPE, ...) \ + #JTYPE, + FLATBUFFERS_GEN_TYPES(FLATBUFFERS_TD) + #undef FLATBUFFERS_TD + }; + // clang-format on + return java_typename[type.base_type]; + } + + std::string GenTypePointer(const Type &type) const { + switch (type.base_type) { + case BASE_TYPE_STRING: return "String"; + case BASE_TYPE_VECTOR: return GenTypeGet(type.VectorType()); + case BASE_TYPE_STRUCT: return WrapInNameSpace(*type.struct_def); + case BASE_TYPE_UNION: FLATBUFFERS_FALLTHROUGH(); // else fall thru + default: return "Table"; + } + } + + std::string GenTypeGet(const Type &type) const { + return IsScalar(type.base_type) + ? GenTypeBasic(type) + : (IsArray(type) ? GenTypeGet(type.VectorType()) + : GenTypePointer(type)); + } + + // Find the destination type the user wants to receive the value in (e.g. + // one size higher signed types for unsigned serialized values in Java). + Type DestinationType(const Type &type, bool vectorelem) const { + switch (type.base_type) { + // We use int for both uchar/ushort, since that generally means less + // casting than using short for uchar. + case BASE_TYPE_UCHAR: return Type(BASE_TYPE_INT); + case BASE_TYPE_USHORT: return Type(BASE_TYPE_INT); + case BASE_TYPE_UINT: return Type(BASE_TYPE_LONG); + case BASE_TYPE_ARRAY: + case BASE_TYPE_VECTOR: + if (vectorelem) return DestinationType(type.VectorType(), vectorelem); + FLATBUFFERS_FALLTHROUGH(); // else fall thru + default: return type; + } + } + + std::string GenOffsetType() const { return "int"; } + + std::string GenOffsetConstruct(const std::string &variable_name) const { + return variable_name; + } + + std::string GenVectorOffsetType() const { return "int"; } + + // Generate destination type name + std::string GenTypeNameDest(const Type &type) const { + return GenTypeGet(DestinationType(type, true)); + } + + // Mask to turn serialized value into destination type value. + std::string DestinationMask(const Type &type, bool vectorelem) const { + switch (type.base_type) { + case BASE_TYPE_UCHAR: return " & 0xFF"; + case BASE_TYPE_USHORT: return " & 0xFFFF"; + case BASE_TYPE_UINT: return " & 0xFFFFFFFFL"; + case BASE_TYPE_VECTOR: + if (vectorelem) return DestinationMask(type.VectorType(), vectorelem); + FLATBUFFERS_FALLTHROUGH(); // else fall thru + default: return ""; + } + } + + // Casts necessary to correctly read serialized data + std::string DestinationCast(const Type &type) const { + if (IsSeries(type)) { + return DestinationCast(type.VectorType()); + } else { + // Cast necessary to correctly read serialized unsigned values. + if (type.base_type == BASE_TYPE_UINT) return "(long)"; + } + return ""; + } + + // Cast statements for mutator method parameters. + // In Java, parameters representing unsigned numbers need to be cast down to + // their respective type. For example, a long holding an unsigned int value + // would be cast down to int before being put onto the buffer. In C#, one cast + // directly cast an Enum to its underlying type, which is essential before + // putting it onto the buffer. + std::string SourceCast(const Type &type, bool castFromDest) const { + if (IsSeries(type)) { + return SourceCast(type.VectorType(), castFromDest); + } else { + if (castFromDest) { + if (type.base_type == BASE_TYPE_UINT) + return "(int)"; + else if (type.base_type == BASE_TYPE_USHORT) + return "(short)"; + else if (type.base_type == BASE_TYPE_UCHAR) + return "(byte)"; + } + } + return ""; + } + + std::string SourceCast(const Type &type) const { + return SourceCast(type, true); + } + + std::string SourceCastBasic(const Type &type, bool castFromDest) const { + return IsScalar(type.base_type) ? SourceCast(type, castFromDest) : ""; + } + + std::string SourceCastBasic(const Type &type) const { + return SourceCastBasic(type, true); + } + + std::string GenEnumDefaultValue(const FieldDef &field) const { + auto &value = field.value; + FLATBUFFERS_ASSERT(value.type.enum_def); + auto &enum_def = *value.type.enum_def; + auto enum_val = enum_def.FindByValue(value.constant); + return enum_val ? (WrapInNameSpace(enum_def) + "." + enum_val->name) + : value.constant; + } + + std::string GenDefaultValue(const FieldDef &field) const { + auto &value = field.value; + auto longSuffix = "L"; + switch (value.type.base_type) { + case BASE_TYPE_BOOL: return value.constant == "0" ? "false" : "true"; + case BASE_TYPE_ULONG: { + // Converts the ulong into its bits signed equivalent + uint64_t defaultValue = StringToUInt(value.constant.c_str()); + return NumToString(static_cast<int64_t>(defaultValue)) + longSuffix; + } + case BASE_TYPE_UINT: + case BASE_TYPE_LONG: return value.constant + longSuffix; + default: + if (IsFloat(value.type.base_type)) + return JavaFloatGen.GenFloatConstant(field); + else + return value.constant; + } + } + + std::string GenDefaultValueBasic(const FieldDef &field) const { + auto &value = field.value; + if (!IsScalar(value.type.base_type)) { return "0"; } + return GenDefaultValue(field); + } + + void GenEnum(EnumDef &enum_def, std::string *code_ptr) const { + std::string &code = *code_ptr; + if (enum_def.generated) return; + + // Generate enum definitions of the form: + // public static (final) int name = value; + // In Java, we use ints rather than the Enum feature, because we want them + // to map directly to how they're used in C/C++ and file formats. + // That, and Java Enums are expensive, and not universally liked. + GenComment(enum_def.doc_comment, code_ptr, &comment_config); + + if (enum_def.attributes.Lookup("private")) { + // For Java, we leave the enum unmarked to indicate package-private + // For C# we mark the enum as internal + } else { + code += "public "; + } + code += "final class " + enum_def.name; + code += " {\n"; + code += " private " + enum_def.name + "() { }\n"; + for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end(); ++it) { + auto &ev = **it; + GenComment(ev.doc_comment, code_ptr, &comment_config, " "); + code += " public static final "; + code += GenTypeBasic(enum_def.underlying_type); + code += " "; + code += ev.name + " = "; + code += enum_def.ToString(ev); + code += ";\n"; + } + + // Generate a generate string table for enum values. + // We do not do that for C# where this functionality is native. + // Problem is, if values are very sparse that could generate really big + // tables. Ideally in that case we generate a map lookup instead, but for + // the moment we simply don't output a table at all. + auto range = enum_def.Distance(); + // Average distance between values above which we consider a table + // "too sparse". Change at will. + static const uint64_t kMaxSparseness = 5; + if (range / static_cast<uint64_t>(enum_def.size()) < kMaxSparseness) { + code += "\n public static final String"; + code += "[] names = { "; + auto val = enum_def.Vals().front(); + for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end(); + ++it) { + auto ev = *it; + for (auto k = enum_def.Distance(val, ev); k > 1; --k) code += "\"\", "; + val = ev; + code += "\"" + (*it)->name + "\", "; + } + code += "};\n\n"; + code += " public static "; + code += "String"; + code += " " + MakeCamel("name", false); + code += "(int e) { return names[e"; + if (enum_def.MinValue()->IsNonZero()) + code += " - " + enum_def.MinValue()->name; + code += "]; }\n"; + } + + // Close the class + code += "}"; + // Java does not need the closing semi-colon on class definitions. + code += ""; + code += "\n\n"; + } + + // Returns the function name that is able to read a value of the given type. + std::string GenGetter(const Type &type) const { + switch (type.base_type) { + case BASE_TYPE_STRING: return "__string"; + case BASE_TYPE_STRUCT: return "__struct"; + case BASE_TYPE_UNION: return "__union"; + case BASE_TYPE_VECTOR: return GenGetter(type.VectorType()); + case BASE_TYPE_ARRAY: return GenGetter(type.VectorType()); + default: { + std::string getter = "bb.get"; + if (type.base_type == BASE_TYPE_BOOL) { + getter = "0!=" + getter; + } else if (GenTypeBasic(type) != "byte") { + getter += MakeCamel(GenTypeBasic(type)); + } + return getter; + } + } + } + + // Returns the function name that is able to read a value of the given type. + std::string GenGetterForLookupByKey(flatbuffers::FieldDef *key_field, + const std::string &data_buffer, + const char *num = nullptr) const { + auto type = key_field->value.type; + auto dest_mask = DestinationMask(type, true); + auto dest_cast = DestinationCast(type); + auto getter = data_buffer + ".get"; + if (GenTypeBasic(type) != "byte") { + getter += MakeCamel(GenTypeBasic(type)); + } + getter = dest_cast + getter + "(" + GenOffsetGetter(key_field, num) + ")" + + dest_mask; + return getter; + } + + // Direct mutation is only allowed for scalar fields. + // Hence a setter method will only be generated for such fields. + std::string GenSetter(const Type &type) const { + if (IsScalar(type.base_type)) { + std::string setter = "bb.put"; + if (GenTypeBasic(type) != "byte" && type.base_type != BASE_TYPE_BOOL) { + setter += MakeCamel(GenTypeBasic(type)); + } + return setter; + } else { + return ""; + } + } + + // Returns the method name for use with add/put calls. + std::string GenMethod(const Type &type) const { + return IsScalar(type.base_type) ? MakeCamel(GenTypeBasic(type)) + : (IsStruct(type) ? "Struct" : "Offset"); + } + + // Recursively generate arguments for a constructor, to deal with nested + // structs. + void GenStructArgs(const StructDef &struct_def, std::string *code_ptr, + const char *nameprefix, size_t array_count = 0) const { + std::string &code = *code_ptr; + for (auto it = struct_def.fields.vec.begin(); + it != struct_def.fields.vec.end(); ++it) { + auto &field = **it; + const auto &field_type = field.value.type; + const auto array_field = IsArray(field_type); + const auto &type = array_field ? field_type.VectorType() + : DestinationType(field_type, false); + const auto array_cnt = array_field ? (array_count + 1) : array_count; + if (IsStruct(type)) { + // Generate arguments for a struct inside a struct. To ensure names + // don't clash, and to make it obvious these arguments are constructing + // a nested struct, prefix the name with the field name. + GenStructArgs(*field_type.struct_def, code_ptr, + (nameprefix + (field.name + "_")).c_str(), array_cnt); + } else { + code += ", "; + code += GenTypeBasic(type); + for (size_t i = 0; i < array_cnt; i++) code += "[]"; + code += " "; + code += nameprefix; + code += MakeCamel(field.name, false); + } + } + } + + // Recusively generate struct construction statements of the form: + // builder.putType(name); + // and insert manual padding. + void GenStructBody(const StructDef &struct_def, std::string *code_ptr, + const char *nameprefix, size_t index = 0, + bool in_array = false) const { + std::string &code = *code_ptr; + std::string indent((index + 1) * 2, ' '); + code += indent + " builder.prep("; + code += NumToString(struct_def.minalign) + ", "; + code += NumToString(struct_def.bytesize) + ");\n"; + for (auto it = struct_def.fields.vec.rbegin(); + it != struct_def.fields.vec.rend(); ++it) { + auto &field = **it; + const auto &field_type = field.value.type; + if (field.padding) { + code += indent + " builder.pad("; + code += NumToString(field.padding) + ");\n"; + } + if (IsStruct(field_type)) { + GenStructBody(*field_type.struct_def, code_ptr, + (nameprefix + (field.name + "_")).c_str(), index, + in_array); + } else { + const auto &type = + IsArray(field_type) ? field_type.VectorType() : field_type; + const auto index_var = "_idx" + NumToString(index); + if (IsArray(field_type)) { + code += indent + " for (int " + index_var + " = "; + code += NumToString(field_type.fixed_length); + code += "; " + index_var + " > 0; " + index_var + "--) {\n"; + in_array = true; + } + if (IsStruct(type)) { + GenStructBody(*field_type.struct_def, code_ptr, + (nameprefix + (field.name + "_")).c_str(), index + 1, + in_array); + } else { + code += IsArray(field_type) ? " " : ""; + code += indent + " builder.put"; + code += GenMethod(type) + "("; + code += SourceCast(type); + auto argname = nameprefix + MakeCamel(field.name, false); + code += argname; + size_t array_cnt = index + (IsArray(field_type) ? 1 : 0); + for (size_t i = 0; in_array && i < array_cnt; i++) { + code += "[_idx" + NumToString(i) + "-1]"; + } + code += ");\n"; + } + if (IsArray(field_type)) { code += indent + " }\n"; } + } + } + } + + std::string GenByteBufferLength(const char *bb_name) const { + std::string bb_len = bb_name; + bb_len += ".capacity()"; + return bb_len; + } + + std::string GenOffsetGetter(flatbuffers::FieldDef *key_field, + const char *num = nullptr) const { + std::string key_offset = ""; + key_offset += "__offset(" + NumToString(key_field->value.offset) + ", "; + if (num) { + key_offset += num; + key_offset += ", _bb)"; + } else { + key_offset += GenByteBufferLength("bb"); + key_offset += " - tableOffset, bb)"; + } + return key_offset; + } + + std::string GenLookupKeyGetter(flatbuffers::FieldDef *key_field) const { + std::string key_getter = " "; + key_getter += "int tableOffset = "; + key_getter += "__indirect(vectorLocation + 4 * (start + middle)"; + key_getter += ", bb);\n "; + if (key_field->value.type.base_type == BASE_TYPE_STRING) { + key_getter += "int comp = "; + key_getter += "compareStrings("; + key_getter += GenOffsetGetter(key_field); + key_getter += ", byteKey, bb);\n"; + } else { + auto get_val = GenGetterForLookupByKey(key_field, "bb"); + key_getter += GenTypeNameDest(key_field->value.type) + " val = "; + key_getter += get_val + ";\n"; + key_getter += " int comp = val > key ? 1 : val < key ? -1 : 0;\n"; + } + return key_getter; + } + + std::string GenKeyGetter(flatbuffers::FieldDef *key_field) const { + std::string key_getter = ""; + auto data_buffer = "_bb"; + if (key_field->value.type.base_type == BASE_TYPE_STRING) { + key_getter += " return "; + key_getter += ""; + key_getter += "compareStrings("; + key_getter += GenOffsetGetter(key_field, "o1") + ", "; + key_getter += GenOffsetGetter(key_field, "o2") + ", " + data_buffer + ")"; + key_getter += ";"; + } else { + auto field_getter = GenGetterForLookupByKey(key_field, data_buffer, "o1"); + key_getter += + "\n " + GenTypeNameDest(key_field->value.type) + " val_1 = "; + key_getter += + field_getter + ";\n " + GenTypeNameDest(key_field->value.type); + key_getter += " val_2 = "; + field_getter = GenGetterForLookupByKey(key_field, data_buffer, "o2"); + key_getter += field_getter + ";\n"; + key_getter += " return val_1 > val_2 ? 1 : val_1 < val_2 ? -1 : 0;\n "; + } + return key_getter; + } + + void GenStruct(StructDef &struct_def, std::string *code_ptr) const { + 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, &comment_config); + if (struct_def.attributes.Lookup("private")) { + // For Java, we leave the struct unmarked to indicate package-private + // For C# we mark the struct as internal + } else { + code += "public "; + } + code += "final "; + code += "class " + struct_def.name; + code += " extends "; + code += struct_def.fixed ? "Struct" : "Table"; + code += " {\n"; + + if (!struct_def.fixed) { + // Generate verson check method. + // Force compile time error if not using the same version runtime. + code += " public static void ValidateVersion() {"; + code += " Constants."; + code += "FLATBUFFERS_1_12_0(); "; + code += "}\n"; + + // Generate a special accessor for the table that when used as the root + // of a FlatBuffer + std::string method_name = "getRootAs" + struct_def.name; + std::string method_signature = + " public static " + struct_def.name + " " + method_name; + + // create convenience method that doesn't require an existing object + code += method_signature + "(ByteBuffer _bb) "; + code += "{ return " + method_name + "(_bb, new " + struct_def.name + + "()); }\n"; + + // create method that allows object reuse + code += + method_signature + "(ByteBuffer _bb, " + struct_def.name + " obj) { "; + code += "_bb.order(ByteOrder.LITTLE_ENDIAN); "; + code += "return (obj.__assign(_bb.getInt(_bb."; + code += "position()"; + code += ") + _bb."; + code += "position()"; + code += ", _bb)); }\n"; + if (parser_.root_struct_def_ == &struct_def) { + if (parser_.file_identifier_.length()) { + // Check if a buffer has the identifier. + code += " public static "; + code += "boolean " + struct_def.name; + code += "BufferHasIdentifier(ByteBuffer _bb) { return "; + code += "__has_identifier(_bb, \""; + code += parser_.file_identifier_; + code += "\"); }\n"; + } + } + } + // Generate the __init method that sets the field in a pre-existing + // accessor object. This is to allow object reuse. + code += " public void __init(int _i, ByteBuffer _bb) "; + code += "{ "; + code += "__reset(_i, _bb); "; + code += "}\n"; + code += + " public " + struct_def.name + " __assign(int _i, ByteBuffer _bb) "; + code += "{ __init(_i, _bb); return this; }\n\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, &comment_config, " "); + std::string type_name = GenTypeGet(field.value.type); + std::string type_name_dest = GenTypeNameDest(field.value.type); + std::string conditional_cast = ""; + std::string optional = ""; + std::string dest_mask = DestinationMask(field.value.type, true); + std::string dest_cast = DestinationCast(field.value.type); + std::string src_cast = SourceCast(field.value.type); + std::string method_start = + " public " + + (field.required ? "" : GenNullableAnnotation(field.value.type)) + + GenPureAnnotation(field.value.type) + type_name_dest + optional + + " " + MakeCamel(field.name, false); + std::string obj = "obj"; + + // Most field accessors need to retrieve and test the field offset first, + // this is the prefix code for that: + auto offset_prefix = + IsArray(field.value.type) + ? " { return " + : (" { int o = __offset(" + NumToString(field.value.offset) + + "); return o != 0 ? "); + // 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 "; + code += 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 "; + code += MakeCamel(field.name, false); + code += "(new " + type_name + "(), j); }\n"; + } + + std::string getter = dest_cast + GenGetter(field.value.type); + code += method_start; + std::string default_cast = ""; + std::string member_suffix = "; "; + if (IsScalar(field.value.type.base_type)) { + code += "()"; + member_suffix += ""; + if (struct_def.fixed) { + code += " { return " + getter; + code += "(bb_pos + "; + code += NumToString(field.value.offset) + ")"; + code += dest_mask; + } else { + code += offset_prefix + getter; + code += "(o + bb_pos)" + dest_mask; + code += " : " + default_cast; + code += GenDefaultValue(field); + } + } else { + switch (field.value.type.base_type) { + case BASE_TYPE_STRUCT: + code += "(" + type_name + " obj)"; + if (struct_def.fixed) { + code += " { return " + obj + ".__assign("; + code += "bb_pos + " + NumToString(field.value.offset) + ", "; + code += "bb)"; + } else { + code += offset_prefix + conditional_cast; + code += obj + ".__assign("; + code += field.value.type.struct_def->fixed + ? "o + bb_pos" + : "__indirect(o + bb_pos)"; + code += ", bb) : null"; + } + break; + case BASE_TYPE_STRING: + code += "()"; + member_suffix += ""; + code += offset_prefix + getter + "(o + "; + code += "bb_pos) : null"; + break; + case BASE_TYPE_ARRAY: FLATBUFFERS_FALLTHROUGH(); // fall thru + case BASE_TYPE_VECTOR: { + auto vectortype = field.value.type.VectorType(); + code += "("; + if (vectortype.base_type == BASE_TYPE_STRUCT) { + code += type_name + " obj, "; + getter = obj + ".__assign"; + } else if (vectortype.base_type == BASE_TYPE_UNION) { + code += type_name + " obj, "; + } + code += "int j)"; + const auto body = offset_prefix + conditional_cast + getter + "("; + if (vectortype.base_type == BASE_TYPE_UNION) { + code += body + "obj, "; + } else { + code += body; + } + std::string index; + if (IsArray(field.value.type)) { + index += "bb_pos + " + NumToString(field.value.offset) + " + "; + } else { + index += "__vector(o) + "; + } + index += "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 += ")" + dest_mask; + if (!IsArray(field.value.type)) { + code += " : "; + code += + field.value.type.element == BASE_TYPE_BOOL + ? "false" + : (IsScalar(field.value.type.element) ? default_cast + "0" + : "null"); + } + + break; + } + case BASE_TYPE_UNION: + code += "(" + type_name + " obj)" + offset_prefix + getter; + code += "(obj, o + bb_pos) : null"; + break; + default: FLATBUFFERS_ASSERT(0); + } + } + code += member_suffix; + code += "}\n"; + if (field.value.type.base_type == BASE_TYPE_VECTOR) { + code += " public int " + MakeCamel(field.name, false); + code += "Length"; + code += "()"; + code += offset_prefix; + code += "__vector_len(o) : 0; "; + code += ""; + code += "}\n"; + // See if we should generate a by-key accessor. + if (field.value.type.element == BASE_TYPE_STRUCT && + !field.value.type.struct_def->fixed) { + auto &sd = *field.value.type.struct_def; + auto &fields = sd.fields.vec; + for (auto kit = fields.begin(); kit != fields.end(); ++kit) { + auto &key_field = **kit; + if (key_field.key) { + auto qualified_name = WrapInNameSpace(sd); + code += " public " + qualified_name + " "; + code += MakeCamel(field.name, false) + "ByKey("; + code += GenTypeNameDest(key_field.value.type) + " key)"; + code += offset_prefix; + code += qualified_name + ".__lookup_by_key("; + code += "null, "; + code += "__vector(o), key, "; + code += "bb) : null; "; + code += "}\n"; + code += " public " + qualified_name + " "; + code += MakeCamel(field.name, false) + "ByKey("; + code += qualified_name + " obj, "; + code += GenTypeNameDest(key_field.value.type) + " key)"; + code += offset_prefix; + code += qualified_name + ".__lookup_by_key(obj, "; + code += "__vector(o), key, "; + code += "bb) : null; "; + code += "}\n"; + break; + } + } + } + } + // Generate the accessors for vector of structs with vector access object + if (field.value.type.base_type == BASE_TYPE_VECTOR) { + std::string vector_type_name; + const auto &element_base_type = field.value.type.VectorType().base_type; + if (IsScalar(element_base_type)) { + vector_type_name = MakeCamel(type_name, true) + "Vector"; + } else if (element_base_type == BASE_TYPE_STRING) { + vector_type_name = "StringVector"; + } else if (element_base_type == BASE_TYPE_UNION) { + vector_type_name = "UnionVector"; + } else { + vector_type_name = type_name + ".Vector"; + } + auto vector_method_start = GenNullableAnnotation(field.value.type) + + " public " + vector_type_name + optional + + " " + MakeCamel(field.name, false) + + "Vector"; + code += vector_method_start + "() { return "; + code += MakeCamel(field.name, false) + "Vector"; + code += "(new " + vector_type_name + "()); }\n"; + code += vector_method_start + "(" + vector_type_name + " obj)"; + code += offset_prefix + conditional_cast + obj + ".__assign("; + code += "__vector(o), "; + if (!IsScalar(element_base_type)) { + auto vectortype = field.value.type.VectorType(); + code += NumToString(InlineSize(vectortype)) + ", "; + } + code += "bb) : null" + member_suffix + "}\n"; + } + // Generate a ByteBuffer accessor for strings & vectors of scalars. + if ((field.value.type.base_type == BASE_TYPE_VECTOR && + IsScalar(field.value.type.VectorType().base_type)) || + field.value.type.base_type == BASE_TYPE_STRING) { + code += " public ByteBuffer "; + code += MakeCamel(field.name, false); + code += "AsByteBuffer() { return "; + code += "__vector_as_bytebuffer("; + code += NumToString(field.value.offset) + ", "; + code += NumToString(field.value.type.base_type == BASE_TYPE_STRING + ? 1 + : InlineSize(field.value.type.VectorType())); + code += "); }\n"; + code += " public ByteBuffer "; + code += MakeCamel(field.name, false); + code += "InByteBuffer(ByteBuffer _bb) { return "; + code += "__vector_in_bytebuffer(_bb, "; + code += NumToString(field.value.offset) + ", "; + code += NumToString(field.value.type.base_type == BASE_TYPE_STRING + ? 1 + : InlineSize(field.value.type.VectorType())); + code += "); }\n"; + } + // generate object accessors if is nested_flatbuffer + if (field.nested_flatbuffer) { + auto nested_type_name = WrapInNameSpace(*field.nested_flatbuffer); + auto nested_method_name = + MakeCamel(field.name, false) + "As" + field.nested_flatbuffer->name; + auto get_nested_method_name = nested_method_name; + code += " public " + nested_type_name + " "; + code += nested_method_name + "() { return "; + code += + get_nested_method_name + "(new " + nested_type_name + "()); }\n"; + code += " public " + nested_type_name + " "; + code += get_nested_method_name + "("; + code += nested_type_name + " obj"; + code += ") { int o = __offset("; + code += NumToString(field.value.offset) + "); "; + code += "return o != 0 ? " + conditional_cast + obj + ".__assign("; + code += ""; + code += "__indirect(__vector(o)), "; + code += "bb) : null; }\n"; + } + // Generate mutators for scalar fields or vectors of scalars. + if (parser_.opts.mutable_buffer) { + auto is_series = (IsSeries(field.value.type)); + const auto &underlying_type = + is_series ? field.value.type.VectorType() : field.value.type; + // Boolean parameters have to be explicitly converted to byte + // representation. + auto setter_parameter = underlying_type.base_type == BASE_TYPE_BOOL + ? "(byte)(" + field.name + " ? 1 : 0)" + : field.name; + auto mutator_prefix = MakeCamel("mutate", false); + // A vector mutator also needs the index of the vector element it should + // mutate. + auto mutator_params = (is_series ? "(int j, " : "(") + + GenTypeNameDest(underlying_type) + " " + + field.name + ") { "; + auto setter_index = + is_series + ? (IsArray(field.value.type) + ? "bb_pos + " + NumToString(field.value.offset) + : "__vector(o)") + + +" + j * " + NumToString(InlineSize(underlying_type)) + : (struct_def.fixed + ? "bb_pos + " + NumToString(field.value.offset) + : "o + bb_pos"); + if (IsScalar(underlying_type.base_type) && !IsUnion(field.value.type)) { + code += " public "; + code += struct_def.fixed ? "void " : "boolean "; + code += mutator_prefix + MakeCamel(field.name, true); + code += mutator_params; + if (struct_def.fixed) { + code += GenSetter(underlying_type) + "(" + setter_index + ", "; + code += src_cast + setter_parameter + "); }\n"; + } else { + code += "int o = __offset("; + code += NumToString(field.value.offset) + ");"; + code += " if (o != 0) { " + GenSetter(underlying_type); + code += "(" + setter_index + ", " + src_cast + setter_parameter + + "); return true; } else { return false; } }\n"; + } + } + } + if (parser_.opts.java_primitive_has_method && + IsScalar(field.value.type.base_type) && !struct_def.fixed) { + auto vt_offset_constant = " public static final int VT_" + + MakeScreamingCamel(field.name) + " = " + + NumToString(field.value.offset) + ";"; + + code += vt_offset_constant; + code += "\n"; + } + } + code += "\n"; + flatbuffers::FieldDef *key_field = nullptr; + if (struct_def.fixed) { + // create a struct constructor function + code += " public static " + GenOffsetType() + " "; + code += "create"; + code += struct_def.name + "(FlatBufferBuilder builder"; + GenStructArgs(struct_def, code_ptr, ""); + code += ") {\n"; + GenStructBody(struct_def, code_ptr, ""); + code += " return "; + code += GenOffsetConstruct("builder." + std::string("offset()")); + code += ";\n }\n"; + } else { + // Generate a method that creates a table in one go. This is only possible + // when the table has no struct fields, since those have to be created + // inline, and there's no way to do so in Java. + bool has_no_struct_fields = true; + int num_fields = 0; + for (auto it = struct_def.fields.vec.begin(); + it != struct_def.fields.vec.end(); ++it) { + auto &field = **it; + if (field.deprecated) continue; + if (IsStruct(field.value.type)) { + has_no_struct_fields = false; + } else { + num_fields++; + } + } + // JVM specifications restrict default constructor params to be < 255. + // Longs and doubles take up 2 units, so we set the limit to be < 127. + if (has_no_struct_fields && num_fields && num_fields < 127) { + // Generate a table constructor of the form: + // public static int createName(FlatBufferBuilder builder, args...) + code += " public static " + GenOffsetType() + " "; + code += "create" + struct_def.name; + code += "(FlatBufferBuilder builder"; + for (auto it = struct_def.fields.vec.begin(); + it != struct_def.fields.vec.end(); ++it) { + auto &field = **it; + if (field.deprecated) continue; + code += ",\n "; + code += GenTypeBasic(DestinationType(field.value.type, false)); + code += " "; + code += field.name; + if (!IsScalar(field.value.type.base_type)) code += "Offset"; + } + code += ") {\n builder."; + code += "startTable("; + code += NumToString(struct_def.fields.vec.size()) + ");\n"; + for (size_t size = struct_def.sortbysize ? sizeof(largest_scalar_t) : 1; + size; size /= 2) { + for (auto it = struct_def.fields.vec.rbegin(); + it != struct_def.fields.vec.rend(); ++it) { + auto &field = **it; + if (!field.deprecated && + (!struct_def.sortbysize || + size == SizeOf(field.value.type.base_type))) { + code += " " + struct_def.name + "."; + code += "add"; + code += MakeCamel(field.name) + "(builder, " + field.name; + if (!IsScalar(field.value.type.base_type)) code += "Offset"; + code += ");\n"; + } + } + } + code += " return " + struct_def.name + "."; + code += "end" + struct_def.name; + code += "(builder);\n }\n\n"; + } + // Generate 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); } + // Unlike the Create function, these always work. + code += " public static void start"; + code += struct_def.name; + code += "(FlatBufferBuilder builder) { builder."; + code += "startTable("; + 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; + if (field.key) key_field = &field; + code += " public static void add"; + code += MakeCamel(field.name); + code += "(FlatBufferBuilder builder, "; + code += GenTypeBasic(DestinationType(field.value.type, false)); + auto argname = MakeCamel(field.name, false); + if (!IsScalar(field.value.type.base_type)) argname += "Offset"; + code += " " + argname + ") { builder.add"; + code += GenMethod(field.value.type) + "("; + code += NumToString(it - struct_def.fields.vec.begin()) + ", "; + code += SourceCastBasic(field.value.type); + code += argname; + code += ", "; + code += SourceCastBasic(field.value.type); + code += GenDefaultValue(field); + code += "); }\n"; + if (field.value.type.base_type == BASE_TYPE_VECTOR) { + auto vector_type = field.value.type.VectorType(); + auto alignment = InlineAlignment(vector_type); + auto elem_size = InlineSize(vector_type); + if (!IsStruct(vector_type)) { + // generate a method to create a vector from a java array. + if ((vector_type.base_type == BASE_TYPE_CHAR || + vector_type.base_type == BASE_TYPE_UCHAR)) { + // Handle byte[] and ByteBuffers separately for Java + code += " public static " + GenVectorOffsetType() + " "; + code += "create"; + code += MakeCamel(field.name); + code += "Vector(FlatBufferBuilder builder, byte[] data) "; + code += "{ return builder.createByteVector(data); }\n"; + + code += " public static " + GenVectorOffsetType() + " "; + code += "create"; + code += MakeCamel(field.name); + code += "Vector(FlatBufferBuilder builder, ByteBuffer data) "; + code += "{ return builder.createByteVector(data); }\n"; + } else { + code += " public static " + GenVectorOffsetType() + " "; + code += "create"; + code += MakeCamel(field.name); + code += "Vector(FlatBufferBuilder builder, "; + code += GenTypeBasic(vector_type) + "[] data) "; + code += "{ builder.startVector("; + code += NumToString(elem_size); + code += ", data.length, "; + code += NumToString(alignment); + code += "); for (int i = data."; + code += "length - 1; i >= 0; i--) builder."; + code += "add"; + code += GenMethod(vector_type); + code += "("; + code += SourceCastBasic(vector_type, false); + code += "data[i]"; + code += "); return "; + code += "builder.endVector(); }\n"; + } + } + // Generate a method to start a vector, data to be added manually + // after. + code += " public static void start"; + code += MakeCamel(field.name); + code += "Vector(FlatBufferBuilder builder, int numElems) "; + code += "{ builder.startVector("; + code += NumToString(elem_size); + code += ", numElems, " + NumToString(alignment); + code += "); }\n"; + } + } + code += " public static " + GenOffsetType() + " "; + code += "end" + struct_def.name; + code += "(FlatBufferBuilder builder) {\n int o = builder."; + code += "endTable();\n"; + for (auto it = struct_def.fields.vec.begin(); + it != struct_def.fields.vec.end(); ++it) { + auto &field = **it; + if (!field.deprecated && field.required) { + code += " builder.required(o, "; + code += NumToString(field.value.offset); + code += "); // " + field.name + "\n"; + } + } + code += " return " + GenOffsetConstruct("o") + ";\n }\n"; + if (parser_.root_struct_def_ == &struct_def) { + std::string size_prefix[] = { "", "SizePrefixed" }; + for (int i = 0; i < 2; ++i) { + code += " public static void "; + code += "finish" + size_prefix[i] + struct_def.name; + code += "Buffer(FlatBufferBuilder builder, " + GenOffsetType(); + code += " offset) {"; + code += " builder.finish" + size_prefix[i] + "(offset"; + + if (parser_.file_identifier_.length()) + code += ", \"" + parser_.file_identifier_ + "\""; + code += "); }\n"; + } + } + } + // Only generate key compare function for table, + // because `key_field` is not set for struct + if (struct_def.has_key && !struct_def.fixed) { + FLATBUFFERS_ASSERT(key_field); + code += "\n @Override\n protected int keysCompare("; + code += "Integer o1, Integer o2, ByteBuffer _bb) {"; + code += GenKeyGetter(key_field); + code += " }\n"; + + code += "\n public static " + struct_def.name; + code += " __lookup_by_key("; + code += struct_def.name + " obj, "; + code += "int vectorLocation, "; + code += GenTypeNameDest(key_field->value.type); + code += " key, ByteBuffer bb) {\n"; + if (key_field->value.type.base_type == BASE_TYPE_STRING) { + code += " byte[] byteKey = "; + code += "key.getBytes(java.nio.charset.StandardCharsets.UTF_8);\n"; + } + code += " int span = "; + code += "bb.getInt(vectorLocation - 4);\n"; + code += " int start = 0;\n"; + code += " while (span != 0) {\n"; + code += " int middle = span / 2;\n"; + code += GenLookupKeyGetter(key_field); + code += " if (comp > 0) {\n"; + code += " span = middle;\n"; + code += " } else if (comp < 0) {\n"; + code += " middle++;\n"; + code += " start += middle;\n"; + code += " span -= middle;\n"; + code += " } else {\n"; + code += " return "; + code += "(obj == null ? new " + struct_def.name + "() : obj)"; + code += ".__assign(tableOffset, bb);\n"; + code += " }\n }\n"; + code += " return null;\n"; + code += " }\n"; + } + GenVectorAccessObject(struct_def, code_ptr); + code += "}"; + code += "\n\n"; + } + + void GenVectorAccessObject(StructDef &struct_def, + std::string *code_ptr) const { + auto &code = *code_ptr; + // Generate a vector of structs accessor class. + code += "\n"; + code += " "; + if (!struct_def.attributes.Lookup("private")) code += "public "; + code += "static "; + code += "final "; + code += "class Vector extends "; + code += "BaseVector {\n"; + + // Generate the __assign method that sets the field in a pre-existing + // accessor object. This is to allow object reuse. + std::string method_indent = " "; + code += method_indent + "public Vector "; + code += "__assign(int _vector, int _element_size, ByteBuffer _bb) { "; + code += "__reset(_vector, _element_size, _bb); return this; }\n\n"; + + auto type_name = struct_def.name; + auto method_start = method_indent + "public " + type_name + " get"; + // Generate the accessors that don't do object reuse. + code += method_start + "(int j) { return get"; + code += "(new " + type_name + "(), j); }\n"; + code += method_start + "(" + type_name + " obj, int j) { "; + code += " return obj.__assign("; + std::string index = "__element(j)"; + code += struct_def.fixed ? index : "__indirect(" + index + ", bb)"; + code += ", bb); }\n"; + // See if we should generate a by-key accessor. + if (!struct_def.fixed) { + auto &fields = struct_def.fields.vec; + for (auto kit = fields.begin(); kit != fields.end(); ++kit) { + auto &key_field = **kit; + if (key_field.key) { + auto nullable_annotation = + parser_.opts.gen_nullable ? "@Nullable " : ""; + code += method_indent + nullable_annotation; + code += "public " + type_name + " "; + code += "getByKey("; + code += GenTypeNameDest(key_field.value.type) + " key) { "; + code += " return __lookup_by_key(null, "; + code += "__vector(), key, "; + code += "bb); "; + code += "}\n"; + code += method_indent + nullable_annotation; + code += "public " + type_name + " "; + code += "getByKey("; + code += type_name + " obj, "; + code += GenTypeNameDest(key_field.value.type) + " key) { "; + code += " return __lookup_by_key(obj, "; + code += "__vector(), key, "; + code += "bb); "; + code += "}\n"; + break; + } + } + } + code += " }\n"; + } + + // This tracks the current namespace used to determine if a type need to be + // prefixed by its namespace + const Namespace *cur_name_space_; +}; +} // namespace java + +bool GenerateJava(const Parser &parser, const std::string &path, + const std::string &file_name) { + java::JavaGenerator generator(parser, path, file_name); + return generator.generate(); +} + +} // namespace flatbuffers |