storage.c

/**
 * @file
 * @brief This file contains the implementation of the storage server
 * interface as specified in storage.h.
 */

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include "storage.h"
#include "utils.h"
#include "file.h"
#include <sys/time.h>
#include <errno.h>
/**
 * @brief for error checking.
 */
int errno;
/**
 * @brief helper variable for checking authorisation.
 */
int auth;


/**
 * @brief This is used to establish a connection with server.
 */
void* storage_connect(const char *hostname, const int port)
{
	char buff[100];
	if (hostname == NULL) {
		errno = ERR_INVALID_PARAM;
		return NULL;
	}
	// Assume port is given in the correct format.
	if (my_strvalidate(hostname, 3)) {
		errno=ERR_INVALID_PARAM;
		return NULL;
	}

	//print statement here will tell us if it started connecting to the server or not
	sprintf(buff, "Attempting to connect to server '%s'\n",
			hostname);
	if (LOGGING == 1) logger(stdout, buff);
	else if (LOGGING == 2) logger(file, buff);
	// Create a socket.
	int sock = socket(PF_INET, SOCK_STREAM, 0);
	if (sock < 0){
		errno=ERR_INVALID_PARAM;    //error :invalid
		return NULL;
	}
	// Get info about the server.
	struct addrinfo serveraddr, *res;
	memset(&serveraddr, 0, sizeof serveraddr);
	serveraddr.ai_family = AF_UNSPEC;
	serveraddr.ai_socktype = SOCK_STREAM;
	char portstr[MAX_PORT_LEN];
	snprintf(portstr, sizeof portstr, "%d", port);
	int status = getaddrinfo(hostname, portstr, &serveraddr, &res);
	if (status != 0){
		errno=ERR_INVALID_PARAM;    //error :invalid
		return NULL;
	}
	// Connect to the server.
	status = connect(sock, res->ai_addr, res->ai_addrlen);
	if (status != 0){
		errno=ERR_CONNECTION_FAIL;    //error :connection failed
		return NULL;
	}
	return (void*) sock;
}


/**
 * @brief This is used to authenticate the arguments from the client
 */
int storage_auth(const char *username, const char *passwd, void *conn)
{
	if (!conn) {
		errno = ERR_CONNECTION_FAIL;
		return -1;
	}
	if (username == NULL) {
		errno = ERR_INVALID_PARAM;
		return -1;
	}
	if (passwd == NULL) {
		errno = ERR_INVALID_PARAM;
		return -1;
	}

	char buff[100];
	//print statement here will tell us if it started logging in
	sprintf(buff, "Attempting to Login with username  '%s'\n",username);

	if (LOGGING == 1) logger(stdout, buff);
	else if (LOGGING == 2) logger(file, buff);
	// Connection is really just a socket file descriptor.
	int sock = (int)conn;

	// Send some data.
	char buf[MAX_CMD_LEN];
	memset(buf, 0, sizeof buf);
	char *encrypted_passwd = generate_encrypted_password(passwd, NULL);
	snprintf(buf, sizeof buf, "AUTH %s %s\n", username, encrypted_passwd);
	if (sendall(sock, buf, strlen(buf)) ==  0 && recvline(sock, buf, sizeof buf) == 0) {
		if (strcmp (buf, "-1") == 0) {
			auth = 0;
			errno = ERR_AUTHENTICATION_FAILED;
			return -1;
		}
		auth=1;
		return 0;
	}
	auth=0;
	errno=ERR_AUTHENTICATION_FAILED;    //error :authentication failed
	return -1;
}

/**
 * @brief This is used to get values back from the database
 */
int storage_get(const char *table, const char *key, struct storage_record *record, void *conn)
{

	if (conn==NULL) {
		errno = ERR_INVALID_PARAM;
		return -1;
	}
	if (!conn) {
		errno = ERR_CONNECTION_FAIL;
		return -1;
	}
	if (record == NULL) {
		errno = ERR_INVALID_PARAM;
		return -1;
	}
	if (table == NULL) {
		errno = ERR_INVALID_PARAM;
		return -1;
	}
	if (key == NULL) {
		errno = ERR_INVALID_PARAM;
		return -1;
	}
	if (strlen(table)>MAX_TABLE_LEN || strlen(key) > MAX_KEY_LEN){
		errno=ERR_INVALID_PARAM;
		return -1;
	}
	if (my_strvalidate(table, 1) ||my_strvalidate(key, 1)){
		errno=ERR_INVALID_PARAM;
		return -1;
	}


	struct timeval start_time, end_time;

	// Remember when the experiment started.
	gettimeofday(&start_time,NULL);
	double t1=start_time.tv_sec+(start_time.tv_usec/1000000.0);

	char buff[100];
	//print statement here will tell us if it started accessing the table
	sprintf(buff, "Accessing table '%s' to fetch value from key '%s'\n",
			table, key);
	if (LOGGING == 1) logger(stdout, buff);
	else if (LOGGING == 2) logger(file, buff);
	// Connection is really just a socket file descriptor.

	int sock = (int)conn;


	// Send some data.
	char buf[MAX_CMD_LEN];
	memset(buf, 0, sizeof buf);
	snprintf(buf, sizeof buf, "GET %s %s\n", table, key);
	if(auth==1){
		if (sendall(sock, buf, strlen(buf)) == 0 && recvline(sock, buf, sizeof buf) == 0) {
			if (strcmp (buf, "-1") == 0) {
				errno = ERR_TABLE_NOT_FOUND;
				return -1;
			}
			if (strcmp (buf, "-2") == 0) {
				errno = ERR_KEY_NOT_FOUND;
				return -1;
			}

			int j = 0;
			j = strcspn (buf, " ");
			record->metadata[0] = atoi(strtok(buf, " "));
			//memset (record->metadata, atoi(strtok(buf, " ")), sizeof(record->metadata));
			
				buf[j] = ' ';;				
			strncpy(record->value, buf+j+1, sizeof record->value);

			// Get the time at the end of the experiment.
			gettimeofday(&end_time,NULL);
			double t2=end_time.tv_sec+(end_time.tv_usec/1000000.0);

			// Calculate difference in time and output it.
		    	double totaltime=t2-t1;


			if (TESTING == 1) {
				FILE* tFile = fopen ("test_times/get", "a");
				fprintf (tFile, "%.6lf\n", totaltime);
				fclose(tFile);
			}
			sprintf(buff,"The total time taken was %.6lf seconds.\n",totaltime);
			if (LOGGING == 1) logger(stdout, buff);
			else if (LOGGING == 2) logger(file, buff);


			return 0;
		}
	}
	else{
		errno=ERR_NOT_AUTHENTICATED;    //error :not authenticated
		return -1;
	}
	// Get the time at the end of the experiment.

	// Calculate difference in time and output it.


	//errno=errno_test;    //error :table or key not found
	return -1;

}


/**
 * @brief This is used to set data into database
 */
int storage_set(const char *table, const char *key, struct storage_record *record, void *conn)
{

	char TEMP[100];
	if (conn==NULL) {
		errno = ERR_INVALID_PARAM;
		return -1;
	}
	if (!conn) {
		errno = ERR_CONNECTION_FAIL;
		return -1;
	}
	if (record != NULL) {
		if (record->value == NULL) {
			errno = ERR_INVALID_PARAM;
			return -1;
		}
	}
	if (table == NULL) {
		errno = ERR_INVALID_PARAM;
		return -1;
	}
	if (key == NULL) {
		errno = ERR_INVALID_PARAM;
		return -1;
	}
	if (strlen(table)>MAX_TABLE_LEN || strlen(key) > MAX_KEY_LEN){
		errno=ERR_INVALID_PARAM;
		return -1;
	}
	if (strlen(table) < 1 || strlen(key) < 1){
			errno=ERR_INVALID_PARAM;
			return -1;
	}
	if (my_strvalidate(table, 1) ||my_strvalidate(key, 1)){
		errno=ERR_INVALID_PARAM;
		return -1;
	}
	struct timeval start_time, end_time;

	// Remember when the experiment started.
	gettimeofday(&start_time,NULL);
	double t1=start_time.tv_sec+(start_time.tv_usec/1000000.0);

	char buff[100];
	strcpy (TEMP, key);
	//print statement here will tell us if it started setting the value to table
	sprintf(buff, "Accessing table '%s' to set value to key '%s'\n",
			table, TEMP);
	if (LOGGING == 1) logger(stdout, buff);
	else if (LOGGING == 2) logger(file, buff);
	// Connection is really just a socket file descriptor.
	int sock = (int)conn;

	// Send some data.
	char buf[MAX_CMD_LEN];
	memset(buf, 0, sizeof buf);
	if (record == NULL)
		snprintf(buf, sizeof buf, "SET %d %s %s %s\n", 0, table, TEMP, "NULL");
	else if (strcmp (record->value, "FILESTORE") == 0)
		snprintf(buf, sizeof buf, "FILE %s \n", table);
	else
		snprintf(buf, sizeof buf, "SET %d %s %s %s\n", record->metadata[0], table, TEMP, record->value);


	if(auth==1){
//	    printf(" sending data \n");
		if (buf != NULL && sendall(sock, buf, strlen(buf)) == 0 && recvline(sock, buf, sizeof buf) == 0) {
			if (strcmp (buf, "-1") == 0) {
				errno = ERR_TABLE_NOT_FOUND;
				return -1;
			}
			if (strcmp (buf, "-2") == 0) {
				errno = ERR_INVALID_PARAM;
				return -1;
			}
			if (strcmp (buf, "-3") == 0) {
				errno = ERR_KEY_NOT_FOUND;
				return -1;
			}
			if (strcmp (buf, "-4") == 0) {
				errno = ERR_TRANSACTION_ABORT;
				return -1;
			}
			// Get the time at the end of the experiment.
			gettimeofday(&end_time,NULL);
			double t2=end_time.tv_sec+(end_time.tv_usec/1000000.0);

			// Calculate difference in time and output it.
		    	double totaltime=t2-t1;


			//printf("The total time taken was %.6lf seconds.\n",totaltime);
//		    printf("The total time taken was %.6lf seconds.\n",totaltime);
			if (TESTING == 1) {
				FILE* tFile = fopen ("test_times/set", "a");
				fprintf (tFile, "%.6lf\n", totaltime);
				fclose(tFile);
			}
			sprintf(buff,"The total time taken was %.6lf seconds.\n",totaltime);
			if (LOGGING == 1) logger(stdout, buff);
			else if (LOGGING == 2) logger(file, buff);



			// Calculate difference in time and output it.


			return 0;
		}
	}
	else{

		printf(" authentication error \n");

		errno=ERR_NOT_AUTHENTICATED;    //error :not authenticated
		return -1;
	}
	// Get the time at the end of the experiment.

	// Calculate difference in time and output it.


    //errno=errno_test;   //key not found
	return -1;
}

/**
 * @brief This is used to query data into database
 */
int storage_query(const char *table, const char *predicates, char **keys, const int max_keys, void *conn) {
	if (!conn) {
		errno = ERR_CONNECTION_FAIL;
		return -1;
	}
	struct timeval start_time, end_time;

	// Remember when the experiment started.
	gettimeofday(&start_time,NULL);
	double t1=start_time.tv_sec+(start_time.tv_usec/1000000.0);

	char buff[100];
	//print statement here will tell us if it started accessing the table
	sprintf(buff, "Accessing table '%s' to fetch keys from predicates: '%s'\n",
			table, predicates);
	if (LOGGING == 1) logger(stdout, buff);
	else if (LOGGING == 2) logger(file, buff);
	// Connection is really just a socket file descriptor.

	int sock = (int)conn;


	// Send some data.
	char buf[MAX_CMD_LEN];
	memset(buf, 0, sizeof buf);
	snprintf(buf, sizeof buf, "QUERY %s %d %s\n", table, max_keys, predicates);
	if(auth==1){
		if (sendall(sock, buf, strlen(buf)) == 0 && recvline(sock, buf, sizeof buf) == 0) {
			
			if (max_keys == 0)
				keys == NULL;

			if (strcmp (buf, "-1") == 0) {
				errno = ERR_TABLE_NOT_FOUND;
				return -1;
			}
			else if (strcmp (buf, "-2") == 0) {
				errno = ERR_INVALID_PARAM;
				return -1;
			}

			if (strcmp (buf, "0") == 0) {
				keys[0] = "";
				return 0;
			}

			// Take buf and parse it for the number of keys and the list of keys and separate them into their appropriate variables (return number and set list into keys).
			int numKeys = 0;
			int i = 0;
			char* arg;
			//char* delims;
			//strcpy (delims, " ");
			arg = strtok (buf, " ");
			numKeys = atoi (arg);
			arg = strtok (NULL, " ");
			while (arg != NULL) {
//				printf (arg);
				strcpy (keys[i], arg);
				i += 1;
				arg = strtok (NULL, " ");
			}

			// Get the time at the end of the experiment.
			gettimeofday(&end_time,NULL);
			double t2=end_time.tv_sec+(end_time.tv_usec/1000000.0);

			// Calculate difference in time and output it.
		    	double totaltime=t2-t1;


//		    printf("The total time taken was %.6lf seconds.\n",totaltime);
			if (TESTING == 1) {
				FILE* tFile = fopen ("test_times/query", "a");
				fprintf (tFile, "%.6lf\n", totaltime);
				fclose(tFile);
			}
			sprintf(buff,"The total time taken was %.6lf seconds.\n",totaltime);
			if (LOGGING == 1) logger(stdout, buff);
			else if (LOGGING == 2) logger(file, buff);


			return numKeys;
		}
	}
	else{
		errno=ERR_NOT_AUTHENTICATED;    //error :not authenticated
		return -1;
	}
	// Get the time at the end of the experiment.

	// Calculate difference in time and output it.


	//errno=errno_test;    //error :table or key not found
	return -1;
}


/**
 * @brief This is used to disconnect the connection
 */
int storage_disconnect(void *conn)
{
	if (!conn) {
		errno = ERR_INVALID_PARAM;
		return -1;
	}
	// Cleanup
	int sock = (int)conn;
	if (sock < 0){
		errno=ERR_INVALID_PARAM;    //error :invalid
		return -1;
	}
	auth = 0;
	int status = close(sock);
	if (status == -1) {
		errno = ERR_UNKNOWN;
		return -1;
	}
	return 0;
}