eive-obsw/bsp_q7s/memory/scratchApi.h

#ifndef BSP_Q7S_MEMORY_SCRATCHAPI_H_
#define BSP_Q7S_MEMORY_SCRATCHAPI_H_

#include <cstdlib>
#include <fstream>
#include <iostream>
#include <sstream>
#include <type_traits>

#include "fsfw/returnvalues/HasReturnvaluesIF.h"
#include "fsfw/serviceinterface/ServiceInterface.h"
#include "linux/utility/utility.h"
#include "returnvalues/classIds.h"

/**
 * @brief   API for the scratch buffer
 */
namespace scratch {

static constexpr char PREFERED_SDC_KEY[] = "PREFSD";
static constexpr char ALLOC_FAILURE_COUNT[] = "ALLOCERR";

static constexpr uint8_t INTERFACE_ID = CLASS_ID::SCRATCH_BUFFER;
static constexpr ReturnValue_t KEY_NOT_FOUND = HasReturnvaluesIF::makeReturnCode(INTERFACE_ID, 0);

ReturnValue_t clearValue(std::string key);

/**
 * Write a string to the scratch buffer
 * @param key
 * @param string    String to write
 * @return
 */
ReturnValue_t writeString(std::string key, std::string string);
/**
 * Read a string from the scratch buffer
 * @param key
 * @param string    Will be set to read string
 * @return
 */
ReturnValue_t readString(std::string key, std::string& string);

/**
 * Write a number to the scratch buffer
 * @tparam T
 * @tparam
 * @param key
 * @param num   Number. Template allows to set signed, unsigned and floating point numbers
 * @return
 */
template <typename T, class = typename std::enable_if<std::is_integral<T>::value>::type>
inline ReturnValue_t writeNumber(std::string key, T num) noexcept;

/**
 * Read a number from the scratch buffer.
 * @tparam T
 * @tparam
 * @param name
 * @param num
 * @return
 */
template <typename T, class = typename std::enable_if<std::is_integral<T>::value>::type>
inline ReturnValue_t readNumber(std::string key, T& num) noexcept;

// Anonymous namespace
namespace {

static uint8_t counter = 0;

ReturnValue_t readToFile(std::string name, std::ifstream& file, std::string& filename) {
  using namespace std;
  filename = "/tmp/sro" + std::to_string(counter++);
  ostringstream oss;
  oss << "xsc_scratch read " << name << " > " << filename;

  int result = std::system(oss.str().c_str());
  if (result != 0) {
    if (WEXITSTATUS(result) == 1) {
      sif::warning << "scratch::readToFile: Key " << name << " does not exist" << std::endl;
      // Could not find value
      std::remove(filename.c_str());
      return KEY_NOT_FOUND;
    } else {
      utility::handleSystemError(result, "scratch::readToFile");
      std::remove(filename.c_str());
      return HasReturnvaluesIF::RETURN_FAILED;
    }
  }
  file.open(filename);
  return HasReturnvaluesIF::RETURN_OK;
}

}  // End of anonymous namespace

template <typename T, class>
inline ReturnValue_t writeNumber(std::string key, T num) noexcept {
  std::ostringstream oss;
  oss << "xsc_scratch write " << key << " " << std::to_string(num);
  int result = std::system(oss.str().c_str());
  if (result != 0) {
    utility::handleSystemError(result, "scratch::writeNumber");
    return HasReturnvaluesIF::RETURN_FAILED;
  }
  return HasReturnvaluesIF::RETURN_OK;
}

template <typename T, class>
inline ReturnValue_t readNumber(std::string key, T& num) noexcept {
  using namespace std;
  ifstream file;
  std::string filename;
  ReturnValue_t result = readToFile(key, file, filename);
  if (result != HasReturnvaluesIF::RETURN_OK) {
    std::remove(filename.c_str());
    return result;
  }

  string line;
  if (not std::getline(file, line)) {
    std::remove(filename.c_str());
    return HasReturnvaluesIF::RETURN_FAILED;
  }

  size_t pos = line.find("=");
  if (pos == string::npos) {
    sif::warning << "scratch::readNumber: Output file format invalid, "
                    "no \"=\" found"
                 << std::endl;
    // Could not find value
    std::remove(filename.c_str());
    return KEY_NOT_FOUND;
  }
  std::string valueAsString = line.substr(pos + 1);
  try {
    num = std::stoi(valueAsString);
  } catch (std::invalid_argument& e) {
    sif::warning << "scratch::readNumber: stoi call failed with " << e.what() << std::endl;
  }

  std::remove(filename.c_str());
  return HasReturnvaluesIF::RETURN_OK;
}

}  // namespace scratch

#endif /* BSP_Q7S_MEMORY_SCRATCHAPI_H_ */