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#pragma once
#include <pthread.h>
#include <sstream>
#define SHM_NAME "/hashtable_queue"
#define QUEUE_SIZE 10
#define MAX_KEY_SIZE 64
#define MAX_VALUE_SIZE 128
/**
* @brief Possible operations on the hashtable.
*/
enum Operations { INSERT, DELETE, GET, PRINT };
/**
* @brief One request constists out of the operation, the arguments and the response.
*/
struct Request {
Operations type;
char key[MAX_KEY_SIZE];
char value[MAX_VALUE_SIZE];
char response[MAX_VALUE_SIZE];
};
/**
* @brief The shared memory between client and server.
*
* @details The shared memory consists out of:
* - A circular-buffer, to de- and enqueue multiple request at once.
* - A mutex with a conditional variable, to ensure concurrency of the buffer.
*/
struct SharedMemory {
Request request[QUEUE_SIZE];
pthread_mutex_t mutex;
pthread_cond_t cond_var;
int tail;
int head;
bool full;
};
/**
* @brief Converts a generic type to a stringstream, so that it can be saved in the shared memory.
*/
template <typename T>
std::string serialize(const T& data)
{
std::ostringstream oss;
oss << data;
return oss.str();
}
/**
* @brief Converts a stringstream to a generic type, so that value in the shared memory can be read.
*/
template <typename T>
T deserialize(const std::string& str)
{
std::istringstream iss(str);
T data;
iss >> data;
return data;
}
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