fsfw/src/fsfw_hal/linux/CommandExecutor.h

130 lines
4.6 KiB
C++

#ifndef FSFW_SRC_FSFW_OSAL_LINUX_COMMANDEXECUTOR_H_
#define FSFW_SRC_FSFW_OSAL_LINUX_COMMANDEXECUTOR_H_
#include <poll.h>
#include <string>
#include <vector>
#include "fsfw/returnvalues/FwClassIds.h"
#include "fsfw/returnvalues/returnvalue.h"
class SimpleRingBuffer;
template <typename T>
class DynamicFIFO;
/**
* @brief Helper class to execute shell commands in blocking and non-blocking mode
* @details
* This class is able to execute processes by using the Linux popen call. It also has the
* capability of writing the read output of a process into a provided ring buffer.
*
* The executor works by first loading the command which should be executed and specifying
* whether it should be executed blocking or non-blocking. After that, execution can be started
* with the execute command. In blocking mode, the execute command will block until the command
* has finished
*/
class CommandExecutor {
public:
enum class States { IDLE, COMMAND_LOADED, PENDING };
static constexpr uint8_t CLASS_ID = CLASS_ID::LINUX_OSAL;
//! [EXPORT] : [COMMENT] Execution of the current command has finished
static constexpr ReturnValue_t EXECUTION_FINISHED = returnvalue::makeCode(CLASS_ID, 0);
//! [EXPORT] : [COMMENT] Command is pending. This will also be returned if the user tries
//! to load another command but a command is still pending
static constexpr ReturnValue_t COMMAND_PENDING = returnvalue::makeCode(CLASS_ID, 1);
//! [EXPORT] : [COMMENT] Some bytes have been read from the executing process
static constexpr ReturnValue_t BYTES_READ = returnvalue::makeCode(CLASS_ID, 2);
//! [EXPORT] : [COMMENT] Command execution failed
static constexpr ReturnValue_t COMMAND_ERROR = returnvalue::makeCode(CLASS_ID, 3);
//! [EXPORT] : [COMMENT]
static constexpr ReturnValue_t NO_COMMAND_LOADED_OR_PENDING = returnvalue::makeCode(CLASS_ID, 4);
static constexpr ReturnValue_t PCLOSE_CALL_ERROR = returnvalue::makeCode(CLASS_ID, 6);
/**
* Constructor. Is initialized with maximum size of internal buffer to read data from the
* executed process.
* @param maxSize
*/
explicit CommandExecutor(size_t maxSize);
/**
* Load a new command which should be executed
* @param command
* @param blocking
* @param printOutput
* @return
*/
ReturnValue_t load(std::string command, bool blocking, bool printOutput = true);
/**
* Execute the loaded command.
* @return
* - In blocking mode, it will return returnvalue::FAILED if
* the result of the system call was not 0. The error value can be accessed using
* getLastError
* - In non-blocking mode, this call will start
* the execution and then return returnvalue::OK
*/
ReturnValue_t execute();
/**
* Only used in non-blocking mode. Checks the currently running command.
* @param bytesRead Will be set to the number of bytes read, if bytes have been read
* @return
* - BYTES_READ if bytes have been read from the executing process. It is recommended to call
* check again after this
* - returnvalue::OK execution is pending, but no bytes have been read from the executing process
* - returnvalue::FAILED if execution has failed, error value can be accessed using getLastError
* - EXECUTION_FINISHED if the process was executed successfully
* - NO_COMMAND_LOADED_OR_PENDING self-explanatory
* - COMMAND_ERROR internal poll error
*/
ReturnValue_t check(bool& replyReceived);
/**
* Abort the current command. Should normally not be necessary, check can be used to find
* out whether command execution was successful
* @return returnvalue::OK
*/
ReturnValue_t close();
States getCurrentState() const;
int getLastError() const;
void printLastError(std::string funcName) const;
/**
* Assign a ring buffer and a FIFO which will be filled by the executor with the output
* read from the started process
* @param ringBuffer
* @param sizesFifo
*/
void setRingBuffer(SimpleRingBuffer* ringBuffer, DynamicFIFO<uint16_t>* sizesFifo);
/**
* Reset the executor. This calls close internally and then reset the state machine so new
* commands can be loaded and executed
*/
void reset();
const std::vector<char>& getReadVector() const;
private:
std::string currentCmd;
bool blocking = true;
FILE* currentCmdFile = nullptr;
int currentFd = 0;
bool printOutput = true;
std::vector<char> readVec;
struct pollfd waiter {};
SimpleRingBuffer* ringBuffer = nullptr;
DynamicFIFO<uint16_t>* sizesFifo = nullptr;
States state = States::IDLE;
int lastError = 0;
ReturnValue_t executeBlocking();
};
#endif /* FSFW_SRC_FSFW_OSAL_LINUX_COMMANDEXECUTOR_H_ */