osquery-1/include/osquery/status.h
2017-07-31 11:06:08 -07:00

131 lines
3.5 KiB
C++

/*
* Copyright (c) 2014-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*
*/
#pragma once
#include <sstream>
#include <string>
namespace osquery {
/**
* @brief A utility class which is used to express the state of operations.
*
* @code{.cpp}
* osquery::Status foobar() {
* auto na = doSomeWork();
* if (na->itWorked()) {
* return osquery::Status(0, "OK");
* } else {
* return osquery::Status(1, na->getErrorString());
* }
* }
* @endcode
*/
class Status {
public:
/**
* @brief Default constructor
*
* Note that the default constructor initialized an osquery::Status instance
* to a state such that a successful operation is indicated.
*/
explicit Status(int c = 0) : code_(c), message_("OK") {}
/**
* @brief A constructor which can be used to concisely express the status of
* an operation.
*
* @param c a status code. The idiom is that a zero status code indicates a
* successful operation and a non-zero status code indicates a failed
* operation.
* @param m a message indicating some extra detail regarding the operation.
* If all operations were successful, this message should be "OK".
* Otherwise, it doesn't matter what the string is, as long as both the
* setter and caller agree.
*/
Status(int c, const std::string& m) : code_(c), message_(m) {}
public:
/**
* @brief A getter for the status code property
*
* @return an integer representing the status code of the operation.
*/
int getCode() const { return code_; }
/**
* @brief A getter for the message property
*
* @return a string representing arbitrary additional information about the
* success or failure of an operation. On successful operations, the idiom
* is for the message to be "OK"
*/
std::string getMessage() const { return message_; }
/**
* @brief A convenience method to check if the return code is 0
*
* @code{.cpp}
* auto s = doSomething();
* if (s.ok()) {
* LOG(INFO) << "doing work";
* } else {
* LOG(ERROR) << s.toString();
* }
* @endcode
*
* @return a boolean which is true if the status code is 0, false otherwise.
*/
bool ok() const { return getCode() == 0; }
/**
* @brief A synonym for osquery::Status::getMessage()
*
* @see getMessage()
*/
std::string toString() const { return getMessage(); }
std::string what() const { return getMessage(); }
/**
* @brief implicit conversion to bool
*
* Allows easy use of Status in an if statement, as below:
*
* @code{.cpp}
* if (doSomethingThatReturnsStatus()) {
* LOG(INFO) << "Success!";
* }
* @endcode
*/
/* explicit */ operator bool() const { return ok(); }
// Below operator implementations useful for testing with gtest
// Enables use of gtest (ASSERT|EXPECT)_EQ
bool operator==(const Status& rhs) const {
return (code_ == rhs.getCode()) && (message_ == rhs.getMessage());
}
// Enables use of gtest (ASSERT|EXPECT)_NE
bool operator!=(const Status& rhs) const { return !operator==(rhs); }
// Enables pretty-printing in gtest (ASSERT|EXPECT)_(EQ|NE)
friend ::std::ostream& operator<<(::std::ostream& os, const Status& s);
private:
/// the internal storage of the status code
int code_;
/// the internal storage of the status message
std::string message_;
};
}