last small formatting fixes

1 files changed, 164 insertions, 0 deletions

diff --git a/src/server/server.h b/src/server/server.h
new file mode 100644
index 0000000..4c019f1
--- /dev/null
+++ b/src/server/server.h
@@ -0,0 +1,164 @@
+#pragma once
+
+#include "hashtable.h"
+#include "shared_memory.h"
+#include <csignal>
+#include <cstring>
+#include <fcntl.h>
+#include <optional>
+#include <sys/mman.h>
+#include <unistd.h>
+
+/**
+ * @class Server
+ * @brief Represents the server, which performs operations on the hashtable based on the requests of
+ * the client.
+ */
+template <typename K, typename V>
+class Server {
+public:
+    /**
+     * @brief Constructs a new hashtable and initializes a shared memory buffer.
+     */
+    Server()
+    {
+        shm_fd = shm_open(SHM_NAME, O_EXCL | O_CREAT | O_RDWR, 0666);
+        if (shm_fd == -1) {
+            std::cout << "Server is already running!" << '\n';
+            exit(-1);
+        }
+
+        ftruncate(shm_fd, sizeof(SharedMemory));
+
+        shared_memory = (SharedMemory*)
+            mmap(0, sizeof(SharedMemory), PROT_READ | PROT_WRITE, MAP_SHARED, shm_fd, 0);
+
+        shared_memory->tail = shared_memory->head = 0;
+
+        pthread_mutexattr_t mutex_attr;
+        pthread_condattr_t cond_attr;
+        pthread_mutexattr_init(&mutex_attr);
+        pthread_mutexattr_setpshared(&mutex_attr, PTHREAD_PROCESS_SHARED);
+        pthread_condattr_init(&cond_attr);
+        pthread_condattr_setpshared(&cond_attr, PTHREAD_PROCESS_SHARED);
+
+        pthread_mutex_init(&shared_memory->mutex, &mutex_attr);
+        pthread_cond_init(&shared_memory->cond_var, &cond_attr);
+    }
+
+    /**
+     * @brief Unmaps and unlinks the shared memory.
+     */
+    ~Server()
+    {
+        munmap(shared_memory, sizeof(SharedMemory));
+        close(shm_fd);
+        shm_unlink(SHM_NAME);
+    }
+
+    /**
+     * @brief Initializes the hashtable.
+     *
+     * @param size The number of buckets in the hashtable.
+     */
+    void initialize_hashtable(size_t size) { hash_table = HashTable<K, V>(size); }
+
+    /**
+     * @brief The main loop of the server.
+     *
+     * @details The server checks the shared memory for new requests and executes them.
+     */
+    void process_requests()
+    {
+        while (true) {
+            pthread_mutex_lock(&shared_memory->mutex);
+
+            if (shared_memory->request[shared_memory->head].status != SENT) {
+                pthread_cond_wait(&shared_memory->cond_var, &shared_memory->mutex);
+            }
+
+            Request* request = &shared_memory->request[shared_memory->head];
+
+            K key = deserialize<K>(request->key);
+            V value = deserialize<V>(request->value);
+
+            switch (request->type) {
+            case INSERT:
+                std::cout << "Insert operation" << '\n';
+                if (hash_table.insert(key, value)) {
+                    strncpy(
+                        request->response,
+                        serialize<std::string>("Inserted successfully").c_str(),
+                        MAX_VALUE_SIZE);
+                } else {
+                    strncpy(
+                        request->response,
+                        serialize<std::string>("Key is already available").c_str(),
+                        MAX_VALUE_SIZE);
+                }
+                break;
+
+            case GET: {
+                std::cout << "Get operation" << '\n';
+                std::optional<V> result = hash_table.get(key);
+                if (result.has_value()) {
+                    std::string response = serialize<V>(result.value());
+                    strncpy(request->response, response.c_str(), MAX_VALUE_SIZE);
+                } else {
+                    strncpy(
+                        request->response,
+                        serialize<std::string>("Couldn't get any value").c_str(),
+                        MAX_VALUE_SIZE);
+                }
+                break;
+            }
+
+            case DELETE:
+                std::cout << "Remove operation" << '\n';
+                if (hash_table.remove(key)) {
+                    strncpy(
+                        request->response,
+                        serialize<std::string>("Key successfully deleted").c_str(),
+                        MAX_VALUE_SIZE);
+                } else {
+                    strncpy(
+                        request->response,
+                        serialize<std::string>("Couldn't find the key").c_str(),
+                        MAX_VALUE_SIZE);
+                }
+                break;
+
+            case PRINT:
+                std::cout << "Print operation" << '\n';
+                strncpy(
+                    request->response,
+                    serialize<std::string>(hash_table.string()).c_str(),
+                    MAX_VALUE_SIZE);
+                break;
+
+            default:
+                break;
+            }
+            shared_memory->request[shared_memory->head].status = PROCESSED;
+            shared_memory->head = (1 + shared_memory->head) % QUEUE_SIZE;
+            pthread_cond_signal(&shared_memory->cond_var);
+            pthread_mutex_unlock(&shared_memory->mutex);
+        }
+    }
+
+private:
+    /**
+     * @brief The hashtable.
+     */
+    HashTable<K, V> hash_table;
+
+    /**
+     * @brief Memory which is shared with the client.
+     */
+    SharedMemory* shared_memory;
+
+    /**
+     * @brief File descriptor for the shared memory, used to unmap and close the memory at the end.
+     */
+    int shm_fd;
+};