/*
* 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/flatbuffers.h"
#include "flatbuffers/idl.h"
#include "flatbuffers/util.h"
#include "flatbuffers/flexbuffers.h"
namespace flatbuffers {
static bool GenStruct(const StructDef &struct_def, const Table *table,
int indent, const IDLOptions &opts,
std::string *_text);
// If indentation is less than 0, that indicates we don't want any newlines
// either.
const char *NewLine(const IDLOptions &opts) {
return opts.indent_step >= 0 ? "\n" : "";
}
int Indent(const IDLOptions &opts) {
return std::max(opts.indent_step, 0);
}
// Output an identifier with or without quotes depending on strictness.
void OutputIdentifier(const std::string &name, const IDLOptions &opts,
std::string *_text) {
std::string &text = *_text;
if (opts.strict_json) text += "\"";
text += name;
if (opts.strict_json) text += "\"";
}
// Print (and its template specialization below for pointers) generate text
// for a single FlatBuffer value into JSON format.
// The general case for scalars:
template<typename T> bool Print(T val, Type type, int /*indent*/,
Type * /*union_type*/,
const IDLOptions &opts,
std::string *_text) {
std::string &text = *_text;
if (type.enum_def && opts.output_enum_identifiers) {
auto enum_val = type.enum_def->ReverseLookup(static_cast<int>(val));
if (enum_val) {
OutputIdentifier(enum_val->name, opts, _text);
return true;
}
}
if (type.base_type == BASE_TYPE_BOOL) {
text += val != 0 ? "true" : "false";
} else {
text += NumToString(val);
}
return true;
}
// Print a vector a sequence of JSON values, comma separated, wrapped in "[]".
template<typename T> bool PrintVector(const Vector<T> &v, Type type,
int indent, const IDLOptions &opts,
std::string *_text) {
std::string &text = *_text;
text += "[";
text += NewLine(opts);
for (uoffset_t i = 0; i < v.size(); i++) {
if (i) {
if (!opts.protobuf_ascii_alike) text += ",";
text += NewLine(opts);
}
text.append(indent + Indent(opts), ' ');
if (IsStruct(type)) {
if (!Print(v.GetStructFromOffset(i * type.struct_def->bytesize), type,
indent + Indent(opts), nullptr, opts, _text)) {
return false;
}
} else {
if (!Print(v[i], type, indent + Indent(opts), nullptr,
opts, _text)) {
return false;
}
}
}
text += NewLine(opts);
text.append(indent, ' ');
text += "]";
return true;
}
// Specialization of Print above for pointer types.
template<> bool Print<const void *>(const void *val,
Type type, int indent,
Type *union_type,
const IDLOptions &opts,
std::string *_text) {
switch (type.base_type) {
case BASE_TYPE_UNION:
// If this assert hits, you have an corrupt buffer, a union type field
// was not present or was out of range.
assert(union_type);
return Print<const void *>(val, *union_type, indent, nullptr, opts,
_text);
case BASE_TYPE_STRUCT:
if (!GenStruct(*type.struct_def,
reinterpret_cast<const Table *>(val),
indent,
opts,
_text)) {
return false;
}
break;
case BASE_TYPE_STRING: {
auto s = reinterpret_cast<const String *>(val);
if (!EscapeString(s->c_str(), s->Length(), _text, opts.allow_non_utf8)) {
return false;
}
break;
}
case BASE_TYPE_VECTOR:
type = type.VectorType();
// Call PrintVector above specifically for each element type:
switch (type.base_type) {
#define FLATBUFFERS_TD(ENUM, IDLTYPE, \
CTYPE, JTYPE, GTYPE, NTYPE, PTYPE) \
case BASE_TYPE_ ## ENUM: \
if (!PrintVector<CTYPE>( \
*reinterpret_cast<const Vector<CTYPE> *>(val), \
type, indent, opts, _text)) { \
return false; \
} \
break;
FLATBUFFERS_GEN_TYPES(FLATBUFFERS_TD)
#undef FLATBUFFERS_TD
}
break;
default: assert(0);
}
return true;
}
// Generate text for a scalar field.
template<typename T> static bool GenField(const FieldDef &fd,
const Table *table, bool fixed,
const IDLOptions &opts,
int indent,
std::string *_text) {
return Print(fixed ?
reinterpret_cast<const Struct *>(table)->GetField<T>(fd.value.offset) :
table->GetField<T>(fd.value.offset, 0), fd.value.type, indent, nullptr,
opts, _text);
}
static bool GenStruct(const StructDef &struct_def, const Table *table,
int indent, const IDLOptions &opts,
std::string *_text);
// Generate text for non-scalar field.
static bool GenFieldOffset(const FieldDef &fd, const Table *table, bool fixed,
int indent, Type *union_type,
const IDLOptions &opts, std::string *_text) {
const void *val = nullptr;
if (fixed) {
// The only non-scalar fields in structs are structs.
assert(IsStruct(fd.value.type));
val = reinterpret_cast<const Struct *>(table)->
GetStruct<const void *>(fd.value.offset);
} else if (fd.flexbuffer) {
auto vec = table->GetPointer<const Vector<uint8_t> *>(fd.value.offset);
auto root = flexbuffers::GetRoot(vec->data(), vec->size());
root.ToString(true, opts.strict_json, *_text);
return true;
} else if (fd.nested_flatbuffer) {
auto vec = table->GetPointer<const Vector<uint8_t> *>(fd.value.offset);
auto root = GetRoot<Table>(vec->data());
return GenStruct(*fd.nested_flatbuffer, root, indent, opts, _text);
} else {
val = IsStruct(fd.value.type)
? table->GetStruct<const void *>(fd.value.offset)
: table->GetPointer<const void *>(fd.value.offset);
}
return Print(val, fd.value.type, indent, union_type, opts, _text);
}
// Generate text for a struct or table, values separated by commas, indented,
// and bracketed by "{}"
static bool GenStruct(const StructDef &struct_def, const Table *table,
int indent, const IDLOptions &opts,
std::string *_text) {
std::string &text = *_text;
text += "{";
int fieldout = 0;
Type *union_type = nullptr;
for (auto it = struct_def.fields.vec.begin();
it != struct_def.fields.vec.end();
++it) {
FieldDef &fd = **it;
auto is_present = struct_def.fixed || table->CheckField(fd.value.offset);
auto output_anyway = opts.output_default_scalars_in_json &&
IsScalar(fd.value.type.base_type) &&
!fd.deprecated;
if (is_present || output_anyway) {
if (fieldout++) {
if (!opts.protobuf_ascii_alike) text += ",";
}
text += NewLine(opts);
text.append(indent + Indent(opts), ' ');
OutputIdentifier(fd.name, opts, _text);
if (!opts.protobuf_ascii_alike ||
(fd.value.type.base_type != BASE_TYPE_STRUCT &&
fd.value.type.base_type != BASE_TYPE_VECTOR)) text += ":";
text += " ";
if (is_present) {
switch (fd.value.type.base_type) {
#define FLATBUFFERS_TD(ENUM, IDLTYPE, \
CTYPE, JTYPE, GTYPE, NTYPE, PTYPE) \
case BASE_TYPE_ ## ENUM: \
if (!GenField<CTYPE>(fd, table, struct_def.fixed, \
opts, indent + Indent(opts), _text)) { \
return false; \
} \
break;
FLATBUFFERS_GEN_TYPES_SCALAR(FLATBUFFERS_TD)
#undef FLATBUFFERS_TD
// Generate drop-thru case statements for all pointer types:
#define FLATBUFFERS_TD(ENUM, IDLTYPE, \
CTYPE, JTYPE, GTYPE, NTYPE, PTYPE) \
case BASE_TYPE_ ## ENUM:
FLATBUFFERS_GEN_TYPES_POINTER(FLATBUFFERS_TD)
#undef FLATBUFFERS_TD
if (!GenFieldOffset(fd, table, struct_def.fixed, indent + Indent(opts),
union_type, opts, _text)) {
return false;
}
break;
}
if (fd.value.type.base_type == BASE_TYPE_UTYPE) {
auto enum_val = fd.value.type.enum_def->ReverseLookup(
table->GetField<uint8_t>(fd.value.offset, 0));
assert(enum_val);
union_type = &enum_val->union_type;
}
}
else
{
text += fd.value.constant;
}
}
}
text += NewLine(opts);
text.append(indent, ' ');
text += "}";
return true;
}
// Generate a text representation of a flatbuffer in JSON format.
bool GenerateText(const Parser &parser, const void *flatbuffer,
std::string *_text) {
std::string &text = *_text;
assert(parser.root_struct_def_); // call SetRootType()
text.reserve(1024); // Reduce amount of inevitable reallocs.
if (!GenStruct(*parser.root_struct_def_,
GetRoot<Table>(flatbuffer),
0,
parser.opts,
_text)) {
return false;
}
text += NewLine(parser.opts);
return true;
}
std::string TextFileName(const std::string &path,
const std::string &file_name) {
return path + file_name + ".json";
}
bool GenerateTextFile(const Parser &parser,
const std::string &path,
const std::string &file_name) {
if (!parser.builder_.GetSize() || !parser.root_struct_def_) return true;
std::string text;
if (!GenerateText(parser, parser.builder_.GetBufferPointer(), &text)) {
return false;
}
return flatbuffers::SaveFile(TextFileName(path, file_name).c_str(),
text,
false);
}
std::string TextMakeRule(const Parser &parser,
const std::string &path,
const std::string &file_name) {
if (!parser.builder_.GetSize() || !parser.root_struct_def_) return "";
std::string filebase = flatbuffers::StripPath(
flatbuffers::StripExtension(file_name));
std::string make_rule = TextFileName(path, filebase) + ": " + file_name;
auto included_files = parser.GetIncludedFilesRecursive(
parser.root_struct_def_->file);
for (auto it = included_files.begin();
it != included_files.end(); ++it) {
make_rule += " " + *it;
}
return make_rule;
}
} // namespace flatbuffers