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/*
* 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"
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*/,
StructDef * /*union_sd*/,
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) {
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;
}
static bool EscapeString(const String &s, std::string *_text, const IDLOptions& opts) {
std::string &text = *_text;
text += "\"";
for (uoffset_t i = 0; i < s.size(); i++) {
char c = s[i];
switch (c) {
case '\n': text += "\\n"; break;
case '\t': text += "\\t"; break;
case '\r': text += "\\r"; break;
case '\b': text += "\\b"; break;
case '\f': text += "\\f"; break;
case '\"': text += "\\\""; break;
case '\\': text += "\\\\"; break;
default:
if (c >= ' ' && c <= '~') {
text += c;
} else {
// Not printable ASCII data. Let's see if it's valid UTF-8 first:
const char *utf8 = s.c_str() + i;
int ucc = FromUTF8(&utf8);
if (ucc < 0) {
if (opts.allow_non_utf8) {
text += "\\x";
text += IntToStringHex(static_cast<uint8_t>(c), 2);
} else {
// There are two cases here:
//
// 1) We reached here by parsing an IDL file. In that case,
// we previously checked for non-UTF-8, so we shouldn't reach
// here.
//
// 2) We reached here by someone calling GenerateText()
// on a previously-serialized flatbuffer. The data might have
// non-UTF-8 Strings, or might be corrupt.
//
// In both cases, we have to give up and inform the caller
// they have no JSON.
return false;
}
} else {
if (ucc <= 0xFFFF) {
// Parses as Unicode within JSON's \uXXXX range, so use that.
text += "\\u";
text += IntToStringHex(ucc, 4);
} else if (ucc <= 0x10FFFF) {
// Encode Unicode SMP values to a surrogate pair using two \u escapes.
uint32_t base = ucc - 0x10000;
auto high_surrogate = (base >> 10) + 0xD800;
auto low_surrogate = (base & 0x03FF) + 0xDC00;
text += "\\u";
text += IntToStringHex(high_surrogate, 4);
text += "\\u";
text += IntToStringHex(low_surrogate, 4);
}
// Skip past characters recognized.
i = static_cast<uoffset_t>(utf8 - s.c_str() - 1);
}
}
break;
}
}
text += "\"";
return true;
}
// Specialization of Print above for pointer types.
template<> bool Print<const void *>(const void *val,
Type type, int indent,
StructDef *union_sd,
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_sd);
if (!GenStruct(*union_sd,
reinterpret_cast<const Table *>(val),
indent,
opts,
_text)) {
return false;
}
break;
case BASE_TYPE_STRUCT:
if (!GenStruct(*type.struct_def,
reinterpret_cast<const Table *>(val),
indent,
opts,
_text)) {
return false;
}
break;
case BASE_TYPE_STRING: {
if (!EscapeString(*reinterpret_cast<const String *>(val), _text, opts)) {
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);
}
// Generate text for non-scalar field.
static bool GenFieldOffset(const FieldDef &fd, const Table *table, bool fixed,
int indent, StructDef *union_sd,
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 {
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_sd, 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;
StructDef *union_sd = 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++) {
text += ",";
}
text += NewLine(opts);
text.append(indent + Indent(opts), ' ');
OutputIdentifier(fd.name, opts, _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_sd, 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_sd = enum_val->struct_def;
}
}
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