FlatBuffers 转换数据字节为JSON字符串的格式。

字符串的格式。"/>

FlatBuffers 转换数据字节为JSON字符串的格式。

flatbuffers::Parser::Parse 函数

parser->opts.strict_json = true;  置为JSON格式。

头文件：

#pragma once#include "prerequisites.h"
#include "msg_define_generated.h"
#include "LoggerManager.h"class MessageDefine final : private boost::noncopyable
{
public:MessageDefine() = default;~MessageDefine() = default;static MessageDefine* instance();void initialize();std::shared_ptr<flatbuffers::Parser> findSchema(const std::string& name);std::shared_ptr<flatbuffers::Parser> findRequestSchema(MSG_DEFINE id);std::shared_ptr<flatbuffers::Parser> findReplySchema(MSG_DEFINE id);template<typename T>inline const T* parseRequestMessage(MSG_DEFINE id, std::string& message, size_t offset){if (message.size() <= offset){LOG_WARNING(default, "Schema size < offset, id[{}]", EnumNameMSG_DEFINE(id));return nullptr;}auto parser = MessageDefine::instance()->findRequestSchema(id);if (!parser){LOG_WARNING(default, "Schema not find, id[{}]", EnumNameMSG_DEFINE(id));return nullptr;}if (!parser->Parse(message.c_str() + offset, nullptr)){LOG_WARNING(default, "Schema parse failed:{}, id[{}], error:{}", message, EnumNameMSG_DEFINE(id), parser->error_);return nullptr;}flatbuffers::Verifier verifier(parser->builder_.GetBufferPointer(), parser->builder_.GetSize());if (verifier.VerifyBuffer<T>(nullptr)){message.resize(parser->builder_.GetSize() + offset);memcpy((char*)(message.c_str() + offset), parser->builder_.GetBufferPointer(), parser->builder_.GetSize());return flatbuffers::GetRoot<T>(message.c_str() + offset);}return nullptr;}template<typename T>inline const T* parseReplyMessage(MSG_DEFINE id, std::string& message, size_t offset){if (message.size() <= offset){LOG_WARNING(default, "Schema size < offset, id[{}]", EnumNameMSG_DEFINE(id));return nullptr;}auto parser = MessageDefine::instance()->findReplySchema(id);if (!parser){LOG_WARNING(default, "Schema not find, id[{}]", EnumNameMSG_DEFINE(id));return nullptr;}if (!parser->Parse(message.c_str() + offset, nullptr)){LOG_WARNING(default, "Schema parse failed:{}, id[{}]", message, EnumNameMSG_DEFINE(id));return nullptr;}flatbuffers::Verifier verifier(parser->builder_.GetBufferPointer(), parser->builder_.GetSize());if (verifier.VerifyBuffer<T>(nullptr)){message.resize(parser->builder_.GetSize() + offset);memcpy((char*)(message.c_str() + offset), parser->builder_.GetBufferPointer(), parser->builder_.GetSize());return flatbuffers::GetRoot<T>(message.c_str() + offset);}return nullptr;}
protected:bool loadSchemaFile(std::string_view path, const std::string& filename, bool bStrict);protected:std::unordered_map<std::string, std::shared_ptr<flatbuffers::Parser>> m_parsers;std::unordered_map<MSG_DEFINE, std::string> m_requestIdNames;std::unordered_map<MSG_DEFINE, std::string> m_replyIdNames;
};template<typename T>
inline const T* json2fb(const std::string& name, const char* message, std::string_view* outMessage)
{auto parser = MessageDefine::instance()->findSchema(name);if (!parser){LOG_WARNING(default, "Schema:{} not find", name);return nullptr;}if (!parser->Parse(message, nullptr)){LOG_WARNING(default, "Schema:{} parse failed:{}", name, message);return nullptr;}flatbuffers::Verifier verifier(parser->builder_.GetBufferPointer(), parser->builder_.GetSize());if (verifier.VerifyBuffer<T>(nullptr)){if (outMessage)*outMessage = std::string_view(reinterpret_cast<char*>(parser->builder_.GetBufferPointer()), parser->builder_.GetSize());return flatbuffers::GetRoot<T>(parser->builder_.GetBufferPointer());}return nullptr;
}inline bool bin2json(const std::string& name, const void* message, std::string& jsongen)
{auto parser = MessageDefine::instance()->findSchema(name);if (!parser){LOG_WARNING(default, "Schema:{} not find", name);return false;}if (!GenerateText(*parser, message, &jsongen)){LOG_WARNING(default, "Schema:{} Couldn't serialize parsed data to JSON", name);return false;}return true;
}

源文件：

#include "MessageDefine.h"
#include "ConfigLoader.h"
#include "MessageDefineConfig_generated.h"MessageDefine* MessageDefine::instance()
{thread_local std::unique_ptr<MessageDefine> tl_instance;if (!tl_instance){tl_instance = std::make_unique<MessageDefine>();tl_instance->initialize();}return tl_instance.get();
}void MessageDefine::initialize()
{TConfigLoader<MessageDefineConfig> cfgMessageDefine;if (!cfgMessageDefine.parse("common/MessageDefineConfig.fbs", "config/MessageDefineConfig.json")){return;}auto cfg = cfgMessageDefine.data;for (auto item : *cfg->items()){auto path = item->path()->string_view();if (item->names()){for (auto name : *item->names()){loadSchemaFile(path, name->str(), true);}}if (item->no_strict_names()){for (auto name : *item->no_strict_names()){loadSchemaFile(path, name->str(), false);}}}for (auto item : *cfg->request_id_names()){m_requestIdNames[item->id()] = item->name()->str();}for (auto item : *cfg->reply_id_names()){m_replyIdNames[item->id()] = item->name()->str();}
}bool MessageDefine::loadSchemaFile(std::string_view path, const std::string& filename, bool bStrict)
{if (m_parsers.find(filename) != m_parsers.end())return true;// load FlatBuffer schema (.fbs)std::string schemafile;std::string schemafilename = fmt::format(path, filename);bool ok = flatbuffers::LoadFile(schemafilename.c_str(), false, &schemafile);if (!ok){LOG_ERROR(network, "couldn't load schemafilename:{}", filename);return false;}// parse schema first, so we can use it to parse the data afterauto parser = std::make_shared<flatbuffers::Parser>();const char* include_directories[] = { "../../fbs", nullptr };ok = parser->Parse(schemafile.c_str(), include_directories);if (!ok){LOG_ERROR(network, "parse schemafilename:{} failed: {}", filename, parser->error_);return false;}if (bStrict){parser->opts.strict_json = true;}m_parsers.emplace(filename, parser);return true;
}std::shared_ptr<flatbuffers::Parser> MessageDefine::findSchema(const std::string& name)
{if (auto it = m_parsers.find(name); it != m_parsers.end()){it->second->builder_.Clear();return it->second;}return nullptr;
}std::shared_ptr<flatbuffers::Parser> MessageDefine::findRequestSchema(MSG_DEFINE id)
{if (auto it = m_requestIdNames.find(id); it != m_requestIdNames.end()){return findSchema(it->second);}return nullptr;
}std::shared_ptr<flatbuffers::Parser> MessageDefine::findReplySchema(MSG_DEFINE id)
{if (auto it = m_replyIdNames.find(id); it != m_replyIdNames.end()){return findSchema(it->second);}return nullptr;
}