lib45d
45Drives C++ Library API Documentation
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ffd::ConfigParser Class Reference

Main configuration parser class to inherit from in your code. More...

#include <45d/config/ConfigParser.hpp>

Public Member Functions

 ConfigParser (std::string path)
 Construct a new Config Parser object. More...
 
std::string dump_str (void) const
 Dump config to stdout as a string. More...
 
template<class T >
T get (const std::string &key) const
 Get value from config map using ffd::get(). This can throw. Use this in a try...catch block. More...
 
template<class T >
T get (const std::string &key, const T &fallback) const noexcept
 Try to get value from config, default to fallback if fails. Guaranteed no-throw. More...
 
template<class T >
T get (const std::string &key, bool *fail_flag) const noexcept
 Try to get value from config. If ffd::get fails, return T() or 0 and set fail_flag. Guaranteed no-throw. Prints message to std::cerr to explain error. More...
 
template<class T >
T get_from (const std::string &section, const std::string &key)
 Adapter for ffd::get(). Sets config_map_ptr_ to address of sub config with name section. This can throw. More...
 
template<class T >
T get_from (const std::string &section, const std::string &key, const T &fallback) noexcept
 Get value from config subsection using ConfigParser::get(const std::string&,const T&) const noexcept, return fallback if the subsection DNE. More...
 
template<class T >
T get_from (const std::string &section, const std::string &key, bool *fail_flag) noexcept
 Get value from config subsection using ConfigParser::get(const std::string&,bool*) const noexcept, set fail_flag if the subsection DNE. More...
 
Quota get_quota (const std::string &key, const Bytes &max) const
 Get quota from config map using ffd::get(). This can throw. Use this in a try...catch block. More...
 
Quota get_quota (const std::string &key, const Bytes &max, const Quota &fallback) const noexcept
 Try to get Quota from config, default to fallback if fails. Guaranteed no-throw. More...
 
Quota get_quota (const std::string &key, const Bytes &max, bool *fail_flag) const noexcept
 Try to get Quota from config. If ffd::get fails, return Quota(void) and set fail_flag. Guaranteed no-throw. Prints message to std::cerr to explain error. More...
 
Quota get_quota_from (const std::string &section, const std::string &key, const Bytes &max)
 Adapter for ffd::get(). Sets config_map_ptr_ to address of sub config with name section. This can throw. More...
 
Quota get_quota_from (const std::string &section, const std::string &key, const Bytes &max, const Quota &fallback) noexcept
 Get value from config subsection using ConfigParser::get(const std::string&,const T&) const noexcept, return fallback if the subsection DNE. More...
 
Quota get_quota_from (const std::string &section, const std::string &key, const Bytes &max, bool *fail_flag) noexcept
 Get value from config subsection using ConfigParser::get(const std::string&,bool*) const noexcept, set fail_flag if the subsection DNE. More...
 

Protected Attributes

std::vector< ConfigNode * > sub_confs_
 Vector of config subsections.
 
std::string current_section_
 Name of current section, set by set_subsection()
 

Friends

class ConfigSubsectionGuard
 Guard to change config subsection within a scope: ConfigSubsectionGuard.
 

Detailed Description

Main configuration parser class to inherit from in your code.

Example usage:

#include <45d/config/ConfigParser.hpp>
#include <cassert>
#include <iostream>
class ConfigFailFlag : public ffd::ConfigParser {
bool parse_failed_ = false;
public:
bool bool_test_ = get<bool>("Bool Test", &parse_failed_);
int integer_test_ = get<int>("Integer Test", &parse_failed_);
unsigned unsigned_test_ = get<unsigned>("Unsigned Test", &parse_failed_);
float float_test_ = get<float>("Float Test", &parse_failed_);
double double_test_ = get<double>("Double Test", &parse_failed_);
std::string string_test_ = get<std::string>("String Test", &parse_failed_);
ConfigFailFlag(std::string path) : ffd::ConfigParser(path) {
if (parse_failed_)
throw ffd::MissingOptionException(
"################ Config Fail Flag ################\nOne or more options missing from configuration.");
}
void dump(void) {
std::cout << "Bool Test: " << std::boolalpha << bool_test_ << std::endl;
std::cout << "Integer Test: " << integer_test_ << std::endl;
std::cout << "Unsigned Test: " << unsigned_test_ << std::endl;
std::cout << "Float Test: " << float_test_ << std::endl;
std::cout << "Double Test: " << double_test_ << std::endl;
std::cout << "String Test: " << string_test_ << std::endl;
}
bool ok(void) {
return !parse_failed_;
}
};
int main(int argc, char *argv[]) {
assert(argc == 2);
{
try {
ConfigFailFlag config(argv[1]);
config.dump();
} catch (const ffd::MissingOptionException &err) {
std::cerr << err.what() << std::endl;
}
}
return 0;
}

Constructor & Destructor Documentation

◆ ConfigParser()

ffd::ConfigParser::ConfigParser ( std::string  path)

Construct a new Config Parser object.

Opens file at path as an std::ifstream and calls ConfigParser::parse()

Parameters
pathPath to config file

Member Function Documentation

◆ dump_str()

std::string ffd::ConfigParser::dump_str ( void  ) const

Dump config to stdout as a string.

Returns
std::string String containing config_map_ contents

◆ get() [1/3]

template<class T >
T ffd::ConfigParser::get ( const std::string &  key) const
inline

Get value from config map using ffd::get(). This can throw. Use this in a try...catch block.

try {
int integer = get<int>("Field");
} catch (const ffd::ConfigException &err) {
std::cerr << err.what();
}
Template Parameters
TType of variable to get
Parameters
keyKey to index config_map_
Returns
T Value returned from config

◆ get() [2/3]

template<class T >
T ffd::ConfigParser::get ( const std::string &  key,
bool *  fail_flag 
) const
inlinenoexcept

Try to get value from config. If ffd::get fails, return T() or 0 and set fail_flag. Guaranteed no-throw. Prints message to std::cerr to explain error.

Example:

#include <45d/config/ConfigParser.hpp>
#include <cassert>
#include <iostream>
class ConfigFailFlag : public ffd::ConfigParser {
bool parse_failed_ = false;
public:
bool bool_test_ = get<bool>("Bool Test", &parse_failed_);
int integer_test_ = get<int>("Integer Test", &parse_failed_);
unsigned unsigned_test_ = get<unsigned>("Unsigned Test", &parse_failed_);
float float_test_ = get<float>("Float Test", &parse_failed_);
double double_test_ = get<double>("Double Test", &parse_failed_);
std::string string_test_ = get<std::string>("String Test", &parse_failed_);
ConfigFailFlag(std::string path) : ffd::ConfigParser(path) {
if (parse_failed_)
throw ffd::MissingOptionException(
"################ Config Fail Flag ################\nOne or more options missing from configuration.");
}
void dump(void) {
std::cout << "Bool Test: " << std::boolalpha << bool_test_ << std::endl;
std::cout << "Integer Test: " << integer_test_ << std::endl;
std::cout << "Unsigned Test: " << unsigned_test_ << std::endl;
std::cout << "Float Test: " << float_test_ << std::endl;
std::cout << "Double Test: " << double_test_ << std::endl;
std::cout << "String Test: " << string_test_ << std::endl;
}
bool ok(void) {
return !parse_failed_;
}
};
int main(int argc, char *argv[]) {
assert(argc == 2);
{
try {
ConfigFailFlag config(argv[1]);
config.dump();
} catch (const ffd::MissingOptionException &err) {
std::cerr << err.what() << std::endl;
}
}
return 0;
}
Template Parameters
TType of variable to return
Parameters
keyKey to index config_map_
fail_flagPointer to flag to set if ffd::get() fails
Returns
T Value returned from config

◆ get() [3/3]

template<class T >
T ffd::ConfigParser::get ( const std::string &  key,
const T &  fallback 
) const
inlinenoexcept

Try to get value from config, default to fallback if fails. Guaranteed no-throw.

Example:

#include <45d/config/ConfigParser.hpp>
#include <cassert>
#include <iostream>
class ConfigFallback : public ffd::ConfigParser {
public:
int integer_test_ = get<int>("Integer Test", -1);
unsigned unsigned_test_ = get<unsigned>("Unsigned Test", (unsigned)-1);
float float_test_ = get<float>("Float Test", -1.0);
double double_test_ = get<double>("Double Test", -1.0);
std::string string_test_ = get<std::string>("String Test", "fallback");
ConfigFallback(std::string path) : ffd::ConfigParser(path) {}
void dump(void) {
std::cout << "Integer Test: " << integer_test_ << std::endl;
std::cout << "Unsigned Test: " << unsigned_test_ << std::endl;
std::cout << "Float Test: " << float_test_ << std::endl;
std::cout << "Double Test: " << double_test_ << std::endl;
std::cout << "String Test: " << string_test_ << std::endl;
}
};
int main(int argc, char *argv[]) {
assert(argc == 2);
{
ConfigFallback config(argv[1]);
config.dump();
}
return 0;
}
Template Parameters
TType of variable to return
Parameters
keyKey to index config_map_
fallbackDefault value to return if ffd::get() fails.
Returns
T Value returned from config

◆ get_from() [1/3]

template<class T >
T ffd::ConfigParser::get_from ( const std::string &  section,
const std::string &  key 
)
inline

Adapter for ffd::get(). Sets config_map_ptr_ to address of sub config with name section. This can throw.

Template Parameters
TType of variable to get
Parameters
sectionSubsection heading from config
keyKey to index config_map_
Returns
T Value returned from config

◆ get_from() [2/3]

template<class T >
T ffd::ConfigParser::get_from ( const std::string &  section,
const std::string &  key,
bool *  fail_flag 
)
inlinenoexcept

Get value from config subsection using ConfigParser::get(const std::string&,bool*) const noexcept, set fail_flag if the subsection DNE.

Template Parameters
TType to return
Parameters
sectionConfig section name to get value from
keyKey identifying value in config
fail_flagPointer to flag to be set if error or DNE
Returns
T Value returned from config or T() or 0

◆ get_from() [3/3]

template<class T >
T ffd::ConfigParser::get_from ( const std::string &  section,
const std::string &  key,
const T &  fallback 
)
inlinenoexcept

Get value from config subsection using ConfigParser::get(const std::string&,const T&) const noexcept, return fallback if the subsection DNE.

Example:

#include <45d/config/ConfigParser.hpp>
#include <cassert>
#include <iostream>
class ConfigSubSections : public ffd::ConfigParser {
private:
bool parse_failed_ = false;
public:
bool global_bool_test_ = get<bool>("Bool Test", &parse_failed_);
int global_integer_test_ = get<int>("Integer Test", &parse_failed_);
unsigned global_unsigned_test_ = get<unsigned>("Unsigned Test", &parse_failed_);
float global_float_test_ = get<float>("Float Test", &parse_failed_);
double global_double_test_ = get<double>("Double Test", &parse_failed_);
std::string global_string_test_ = get<std::string>("String Test", &parse_failed_);
bool section1_bool_test_ = get_from<bool>("Section 1", "Bool Test", &parse_failed_);
int section1_integer_test_ = get_from<int>("Section 1", "Integer Test", &parse_failed_);
unsigned section1_unsigned_test_ =
get_from<unsigned>("Section 1", "Unsigned Test", &parse_failed_);
float section1_float_test_ = get_from<float>("Section 1", "Float Test", &parse_failed_);
double section1_double_test_ = get_from<double>("Section 1", "Double Test", &parse_failed_);
std::string section1_string_test_ =
get_from<std::string>("Section 1", "String Test", &parse_failed_);
bool section2_bool_test_ = get_from<bool>("Section 2", "Bool Test", &parse_failed_);
int section2_integer_test_ = get_from<int>("Section 2", "Integer Test", &parse_failed_);
unsigned section2_unsigned_test_ =
get_from<unsigned>("Section 2", "Unsigned Test", &parse_failed_);
float section2_float_test_ = get_from<float>("Section 2", "Float Test", &parse_failed_);
double section2_double_test_ = get_from<double>("Section 2", "Double Test", &parse_failed_);
std::string section2_string_test_ =
get_from<std::string>("Section 2", "String Test", &parse_failed_);
ConfigSubSections(std::string path) : ffd::ConfigParser(path) {}
void dump(void) {
std::cout << "Global Bool Test: " << std::boolalpha << global_bool_test_ << std::endl;
std::cout << "Global Integer Test: " << global_integer_test_ << std::endl;
std::cout << "Global Unsigned Test: " << global_unsigned_test_ << std::endl;
std::cout << "Global Float Test: " << global_float_test_ << std::endl;
std::cout << "Global Double Test: " << global_double_test_ << std::endl;
std::cout << "Global String Test: " << global_string_test_ << std::endl;
std::cout << "Section 1 Bool Test: " << std::boolalpha << section1_bool_test_ << std::endl;
std::cout << "Section 1 Integer Test: " << section1_integer_test_ << std::endl;
std::cout << "Section 1 Unsigned Test: " << section1_unsigned_test_ << std::endl;
std::cout << "Section 1 Float Test: " << section1_float_test_ << std::endl;
std::cout << "Section 1 Double Test: " << section1_double_test_ << std::endl;
std::cout << "Section 1 String Test: " << section1_string_test_ << std::endl;
std::cout << "Section 2 Bool Test: " << std::boolalpha << section2_bool_test_ << std::endl;
std::cout << "Section 2 Integer Test: " << section2_integer_test_ << std::endl;
std::cout << "Section 2 Unsigned Test: " << section2_unsigned_test_ << std::endl;
std::cout << "Section 2 Float Test: " << section2_float_test_ << std::endl;
std::cout << "Section 2 Double Test: " << section2_double_test_ << std::endl;
std::cout << "Section 2 String Test: " << section2_string_test_ << std::endl;
}
};
int main(int argc, char *argv[]) {
assert(argc == 2);
ConfigSubSections config(argv[1]);
config.dump();
return 0;
}
Template Parameters
TType to return
Parameters
sectionConfig section name to get value from
keyKey identifying value in config
fallbackReturned if error or DNE
Returns
T Value returned from config or fallback

◆ get_quota() [1/3]

Quota ffd::ConfigParser::get_quota ( const std::string &  key,
const Bytes &  max 
) const
inline

Get quota from config map using ffd::get(). This can throw. Use this in a try...catch block.

ffd::Bytes total(1024);
try {
ffd::Quota quota = get("Quota", total);
} catch (const ffd::ConfigException &err) {
std::cerr << err.what();
}
Parameters
keyKey to index config_map_
maxMaximum number of bytes
Returns
ffd::Quota Value returned from config

◆ get_quota() [2/3]

Quota ffd::ConfigParser::get_quota ( const std::string &  key,
const Bytes &  max,
bool *  fail_flag 
) const
inlinenoexcept

Try to get Quota from config. If ffd::get fails, return Quota(void) and set fail_flag. Guaranteed no-throw. Prints message to std::cerr to explain error.

Parameters
keyKey to index config_map_
maxMaximum number of bytes
fail_flagPointer to flag to set if ffd::get() fails
Returns
T Value returned from config

◆ get_quota() [3/3]

Quota ffd::ConfigParser::get_quota ( const std::string &  key,
const Bytes &  max,
const Quota &  fallback 
) const
inlinenoexcept

Try to get Quota from config, default to fallback if fails. Guaranteed no-throw.

Parameters
keyKey to index config_map_
maxMaximum number of bytes
fallbackDefault value to return if ffd::get() fails.
Returns
T Value returned from config

◆ get_quota_from() [1/3]

Quota ffd::ConfigParser::get_quota_from ( const std::string &  section,
const std::string &  key,
const Bytes &  max 
)
inline

Adapter for ffd::get(). Sets config_map_ptr_ to address of sub config with name section. This can throw.

Parameters
sectionSubsection heading from config
keyKey to index config_map_
maxMaximum number of bytes
Returns
Quota Value returned from config

◆ get_quota_from() [2/3]

Quota ffd::ConfigParser::get_quota_from ( const std::string &  section,
const std::string &  key,
const Bytes &  max,
bool *  fail_flag 
)
inlinenoexcept

Get value from config subsection using ConfigParser::get(const std::string&,bool*) const noexcept, set fail_flag if the subsection DNE.

Parameters
sectionConfig section name to get value from
keyKey identifying value in config
maxMaximum number of bytes
fail_flagPointer to flag to be set if error or DNE
Returns
Quota Value returned from config or T() or 0

◆ get_quota_from() [3/3]

Quota ffd::ConfigParser::get_quota_from ( const std::string &  section,
const std::string &  key,
const Bytes &  max,
const Quota &  fallback 
)
inlinenoexcept

Get value from config subsection using ConfigParser::get(const std::string&,const T&) const noexcept, return fallback if the subsection DNE.

Example:

#include <45d/config/ConfigParser.hpp>
#include <cassert>
#include <iostream>
class ConfigSubSections : public ffd::ConfigParser {
private:
bool parse_failed_ = false;
public:
bool global_bool_test_ = get<bool>("Bool Test", &parse_failed_);
int global_integer_test_ = get<int>("Integer Test", &parse_failed_);
unsigned global_unsigned_test_ = get<unsigned>("Unsigned Test", &parse_failed_);
float global_float_test_ = get<float>("Float Test", &parse_failed_);
double global_double_test_ = get<double>("Double Test", &parse_failed_);
std::string global_string_test_ = get<std::string>("String Test", &parse_failed_);
bool section1_bool_test_ = get_from<bool>("Section 1", "Bool Test", &parse_failed_);
int section1_integer_test_ = get_from<int>("Section 1", "Integer Test", &parse_failed_);
unsigned section1_unsigned_test_ =
get_from<unsigned>("Section 1", "Unsigned Test", &parse_failed_);
float section1_float_test_ = get_from<float>("Section 1", "Float Test", &parse_failed_);
double section1_double_test_ = get_from<double>("Section 1", "Double Test", &parse_failed_);
std::string section1_string_test_ =
get_from<std::string>("Section 1", "String Test", &parse_failed_);
bool section2_bool_test_ = get_from<bool>("Section 2", "Bool Test", &parse_failed_);
int section2_integer_test_ = get_from<int>("Section 2", "Integer Test", &parse_failed_);
unsigned section2_unsigned_test_ =
get_from<unsigned>("Section 2", "Unsigned Test", &parse_failed_);
float section2_float_test_ = get_from<float>("Section 2", "Float Test", &parse_failed_);
double section2_double_test_ = get_from<double>("Section 2", "Double Test", &parse_failed_);
std::string section2_string_test_ =
get_from<std::string>("Section 2", "String Test", &parse_failed_);
ConfigSubSections(std::string path) : ffd::ConfigParser(path) {}
void dump(void) {
std::cout << "Global Bool Test: " << std::boolalpha << global_bool_test_ << std::endl;
std::cout << "Global Integer Test: " << global_integer_test_ << std::endl;
std::cout << "Global Unsigned Test: " << global_unsigned_test_ << std::endl;
std::cout << "Global Float Test: " << global_float_test_ << std::endl;
std::cout << "Global Double Test: " << global_double_test_ << std::endl;
std::cout << "Global String Test: " << global_string_test_ << std::endl;
std::cout << "Section 1 Bool Test: " << std::boolalpha << section1_bool_test_ << std::endl;
std::cout << "Section 1 Integer Test: " << section1_integer_test_ << std::endl;
std::cout << "Section 1 Unsigned Test: " << section1_unsigned_test_ << std::endl;
std::cout << "Section 1 Float Test: " << section1_float_test_ << std::endl;
std::cout << "Section 1 Double Test: " << section1_double_test_ << std::endl;
std::cout << "Section 1 String Test: " << section1_string_test_ << std::endl;
std::cout << "Section 2 Bool Test: " << std::boolalpha << section2_bool_test_ << std::endl;
std::cout << "Section 2 Integer Test: " << section2_integer_test_ << std::endl;
std::cout << "Section 2 Unsigned Test: " << section2_unsigned_test_ << std::endl;
std::cout << "Section 2 Float Test: " << section2_float_test_ << std::endl;
std::cout << "Section 2 Double Test: " << section2_double_test_ << std::endl;
std::cout << "Section 2 String Test: " << section2_string_test_ << std::endl;
}
};
int main(int argc, char *argv[]) {
assert(argc == 2);
ConfigSubSections config(argv[1]);
config.dump();
return 0;
}
Parameters
sectionConfig section name to get value from
keyKey identifying value in config
maxMaximum number of bytes
fallbackReturned if error or DNE
Returns
Quota Value returned from config or fallback
The documentation for this class was generated from the following files:
ffd::ConfigParser::ConfigParser
ConfigParser(std::string path)
Construct a new Config Parser object.
Definition: config_parser.cpp:25
ffd::Bytes
Use this class for byte-formatted values. e.g.: "123 KiB".
Definition: Bytes.hpp:32
ffd::Quota
This class extends ffd::Bytes to specify percents of an amount of bytes.
Definition: Quota.hpp:30
ffd::ConfigParser::get
T get(const std::string &key) const
Get value from config map using ffd::get(). This can throw. Use this in a try...catch block.
Definition: ConfigParser.hpp:105
ffd
45Drives namespace
Definition: Bytes.hpp:27
ffd::MissingOptionException
Throw this exception when a config entry is missing.
Definition: Exceptions.hpp:48
ffd::Exception::what
const char * what(void) const noexcept
Return string containing explanation message.
Definition: Exceptions.hpp:44
ffd::ConfigException
General exception for all Config* related issues.
Definition: Exceptions.hpp:30
ffd::ConfigParser
Main configuration parser class to inherit from in your code.
Definition: ConfigParser.hpp:68
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