Parser
class Parser {
public:
// LineCallback is the type for callbacks that can parse a line starting with a given prefix.
//
// They take the form of bool Callback(std::vector<std::string>&& args, std::string* err)
//
// Similar to ParseSection() and ParseLineSection(), this function returns bool with false
// indicating a failure and has an std::string* err parameter into which an error string can
// be written.
using LineCallback = std::function<Result<Success>(std::vector<std::string>&&)>;
Parser();
bool ParseConfig(const std::string& path);
bool ParseConfig(const std::string& path, size_t* parse_errors);
void AddSectionParser(const std::string& name, std::unique_ptr<SectionParser> parser);
void AddSingleLineParser(const std::string& prefix, LineCallback callback);
private:
void ParseData(const std::string& filename, const std::string& data, size_t* parse_errors);
bool ParseConfigFile(const std::string& path, size_t* parse_errors);
bool ParseConfigDir(const std::string& path, size_t* parse_errors);
std::map<std::string, std::unique_ptr<SectionParser>> section_parsers_;
std::vector<std::pair<std::string, LineCallback>> line_callbacks_;
};
Parser中包括SectionParser类型的容器section_parsers_。
SectionParser
class SectionParser {
public:
virtual ~SectionParser() {}
virtual Result<Success> ParseSection(std::vector<std::string>&& args,
const std::string& filename, int line) = 0;
virtual Result<Success> ParseLineSection(std::vector<std::string>&&, int) { return Success(); };
virtual Result<Success> EndSection() { return Success(); };
virtual void EndFile(){};
};
SectionParser是一个抽象类。
ActionParser
class ActionParser : public SectionParser {
public:
ActionParser(ActionManager* action_manager, std::vector<Subcontext>* subcontexts)
: action_manager_(action_manager), subcontexts_(subcontexts), action_(nullptr) {}
Result<Success> ParseSection(std::vector<std::string>&& args, const std::string& filename,
int line) override;
Result<Success> ParseLineSection(std::vector<std::string>&& args, int line) override;
Result<Success> EndSection() override;
private:
ActionManager* action_manager_;
std::vector<Subcontext>* subcontexts_;
std::unique_ptr<Action> action_;
};
ImportParser
class ImportParser : public SectionParser {
public:
ImportParser(Parser* parser) : parser_(parser) {}
Result<Success> ParseSection(std::vector<std::string>&& args, const std::string& filename,
int line) override;
void EndFile() override;
private:
Parser* parser_;
// Store filename for later error reporting.
std::string filename_;
// Vector of imports and their line numbers for later error reporting.
std::vector<std::pair<std::string, int>> imports_;
};
ServiceParser
class ServiceParser : public SectionParser {
public:
ServiceParser(ServiceList* service_list, std::vector<Subcontext>* subcontexts)
: service_list_(service_list), subcontexts_(subcontexts), service_(nullptr) {}
Result<Success> ParseSection(std::vector<std::string>&& args, const std::string& filename,
int line) override;
Result<Success> ParseLineSection(std::vector<std::string>&& args, int line) override;
Result<Success> EndSection() override;
private:
bool IsValidName(const std::string& name) const;
ServiceList* service_list_;
std::vector<Subcontext>* subcontexts_;
std::unique_ptr<Service> service_;
};
