struct Connection *Database_open(const char *filename, char mode) {
struct Connection *conn = malloc(sizeof(struct Connection));
if (!conn) die("Memory Error");
conn->db = malloc(sizeof(struct Database));
if (!conn->db) die("Memory Error");
if (mode == 'c') {
conn->file = fopen(filename, "w");
} else {
conn->file = fopen(filename, "r+");
if (conn->file) {
Database_load(conn);
}
}
if (!conn->file) die("Failed to open the file");
return conn;
};
void Database_open(const char *filename, char mode)
{
int i;
conn = malloc(sizeof(struct Connection));
if(!conn) die("Memory error.");
conn->db = malloc(sizeof(struct Database));
if(!conn->db) die("Memory error.");
if(mode == 'c') {
conn->file = fopen(filename, "w");
} else {
conn->file = fopen(filename, "r+");
fread(&max_rows, sizeof(int), 1, conn->file);
fread(&max_data, sizeof(int), 1, conn->file);
}
if(!conn->file) die("Failed to open the file");
conn->db->rows = malloc(sizeof(struct Address) * max_rows);
if(!conn->db->rows) die("Memory error.");
for (i = 0; i < max_rows; i++) {
conn->db->rows[i].id = i;
conn->db->rows[i].set = 0;
conn->db->rows[i].name = calloc(1, sizeof(char) * max_data);
if (!conn->db->rows[i].name) die("Memory error");
conn->db->rows[i].email = calloc(1, sizeof(char) * max_data);
if (!conn->db->rows[i].email) die("Memory error");
conn->db->rows[i].name[max_data - 1] = '\0';
conn->db->rows[i].email[max_data - 1] = '\0';
}
if (mode != 'c') {
if(conn->file) {
Database_load();
}
}
}
struct Connection *Database_open(const char *filename, char mode) //allocates memory to the database
{
struct Connection *conn = malloc(sizeof(struct Connection));
if(!conn) die("Memory error");
conn->db = malloc(sizeof(struct Database)); //block of memory size equaling the size of the database
if(!conn->db) die("Memory error");
if(mode == 'c') {
conn->file = fopen(filename, "w"); //if we want to create a database...
} else {
conn->file = fopen(filename, "r+");
if(conn->file){
Database_load(conn);
}
}
if(!conn->file) die("Failed to open the file");
return conn;
}
void Database_delete(int id) {
struct Address addr = {.id = id, .set = 0}
;
// Yep, need to allocate the memory for these strings here too;
// just like we did when we first initialized all the Addresses.
addr.name = malloc(sizeof(char) * conn->db->max_data);
addr.email = malloc(sizeof(char) * conn->db->max_data);
conn->db->rows[id] = addr;
}
void Database_list() {
struct Database *db = conn->db;
printf("MAX_DATA: %d\n", db->max_data);
printf("MAX_ROWS: %d\n", db->max_rows);
int i = 0;
for (i = 0; i < db->max_rows; i++) {
struct Address *cur = &db->rows[i];
if (cur->set)
Address_print(cur);
}
}
void Database_open(const char *filename, char mode) {
// Initialize the global connection
conn = malloc(sizeof(struct Connection));
if (!conn)
die("Memory error.");
conn->db = malloc(sizeof(struct Database));
if (!conn->db)
die("Memory error");
if (mode == 'c') {
conn->file = fopen(filename, "w");
} else {
conn->file = fopen(filename, "r+");
if (conn->file)
Database_load();
}
if (!conn->file)
die("Failed to open file.");
}
struct Connection *Database_open(const char *filename, char mode)
{
struct Connection *conn = malloc(sizeof(struct Connection));
if(!conn) die("Memory error");
// This could happen when memory in your computer is exhausted.
conn->db = malloc(sizeof(struct Database));
if(!conn->db) die("Memory error");
if(mode == 'c') {
conn->file = fopen(filename, "w");
} else {
conn->file = fopen(filename, "r+");
if(conn->file) {
Database_load(conn);
}
}
if(!conn->file) die("Failed to open the file");
return conn;
}
struct Connection *Database_open(const char *filename, char mode)
{
//printf("Allocated memory for connection\n");
struct Connection *conn = malloc(sizeof(struct Connection));
if(!conn) die("Memory error.", conn);
//printf("Allocated memory for database\n");
conn->db = malloc(sizeof(struct Database));
if(!conn->db) die("Memory error.", conn);
if(mode == 'c') {
conn->file = fopen(filename, "w");
} else {
conn->file = fopen(filename, "r+");
if(conn->file) {
Database_load(conn);
}
}
if(!conn->file) die("Failed to open the file.", conn);
return conn;
}
struct Connection* Database_open(const char *filename, char mode, int max_rows, int max_data) {
struct Connection *conn = malloc(sizeof(struct Connection));
if(!conn) die("Memory Error");
// conn->db = malloc(sizeof(struct Database));
long size = sizeof(struct Database) + ((sizeof(struct Address) + (max_data * 2)) * max_rows);
conn->db = malloc(size);
if(!conn->db) die ("Memory Error");
if(mode == 'c') {
conn->file = fopen(filename, "w");
} else {
conn->file = fopen(filename, "r+");
if(conn->file) {
Database_load(conn, size);
printf("loaded db with max rows %d and max data %d\n", conn->db->max_rows, conn->db->max_data);
}
}
if(!conn->file) die("Failed to open the file");
return conn;
}
void Database_create(struct Connection *conn, int max_rows, int max_data)
{
conn->db->max_rows = max_rows;
conn->db->max_data = max_data;
Database_alloc_rows(conn);
int i = 0;
for(i = 0; i < max_rows; i++) {
struct Address addr = { .id = i, .set = 0};
addr.email = malloc(sizeof(char) * conn->db->max_data);
addr.name = malloc(sizeof(char) * conn->db->max_data);
conn->db->rows[i] = addr;
}
}
struct Connection *Database_open(const char *filename, char mode)
{
struct Connection *conn = malloc(sizeof(struct Connection));
if(!conn) die("Memory error", conn);
conn->db = malloc(sizeof(struct Database));
if(!conn->db) die("Memory error", conn);
if(mode == 'c') {
conn->file = fopen(filename, "w");
} else {
conn->file = fopen(filename, "r+");
if(conn->file) {
Database_load(conn);
}
}
if(!conn->file) die("Failed to open the file", conn);
return conn;
}
void Database_close(struct Connection *conn)
{
if(conn) {
if(conn->file) fclose(conn->file);
if(conn->db->rows) free(conn->db->rows);
if(conn->db) free(conn->db);
free(conn);
}
}
void Database_set(struct Connection *conn, int id, const char *name, const char *email)
{
struct Address *addr = &conn->db->rows[id];
if(addr->set) die("Already set, delete it first", conn);
addr->set = 1;
//WARNING: bug, read the "How to break it" and fix this
char *res = strncpy(addr->name, name, conn->db->max_data);
//demonstrate the strncpy bug
if(!res) die("Name copy failed", conn);
res = strncpy(addr->email, email, conn->db->max_data);
if(!res) die("Email copy failed", conn);
}
void Database_get(struct Connection *conn, int id)
{
if(id > conn->db->max_rows) {
die("There's not that many rows", conn);
}
struct Address *addr = &conn->db->rows[id];
if(addr->set) {
Address_print(addr);
} else {
die("ID not set", conn);
}
}
void Database_delete(struct Connection *conn, int id) {
struct Address addr = {.id = id, .set = 0};
addr.email = malloc(sizeof(char) * conn->db->max_data);
addr.name = malloc(sizeof(char) * conn->db->max_data);
conn->db->rows[id] = addr;
}
void Database_list(struct Connection *conn)
{
int i = 0;
for(i=0; i< conn->db->max_rows; i++) {
struct Address *cur = &(conn->db->rows[i]);
if(cur->set) {
Address_print(cur);
}
}
}
int main(int argc, char *argv[])
{
if(argc < 3) die("USAGE: ex17 <dbfile> <action> [action params]", NULL);
char *filename = argv[1];
char action = argv[2][0];
struct Connection *conn = Database_open(filename, action);
int param1 = 0;
int param2 = 0;
int max_rows = 100;
int max_data = 512;
if(argc > 3) {
param1 = atoi(argv[3]);
}
if(argc > 4) {
param2 = atoi(argv[4]);
}
switch(action) {
case 'c':
if(argc > 3) {
max_rows = param1;
}
if(argc > 4) {
max_data = param2;
}
Database_create(conn, max_rows, max_data);
Database_write(conn);
break;
case 'g':
if(argc != 4) die("Need an id to get", conn);
Database_get(conn, param1);
break;
case 's':
if(argc != 6) die("Need id, name, email to set", conn);
Database_set(conn, param1, argv[4], argv[5]);
Database_write(conn);
break;
case 'd':
if(argc != 4) die("Need an id to delete", conn);
Database_delete(conn, param1);
Database_write(conn);
break;
case 'l':
Database_list(conn);
break;
default:
die("Invalid action, only: c=create, g-get, s=set, d=del, l=list", conn);
}
Database_close(conn);
return 0;
}
