class DirectoryService(Database):
DATABASE = "sql.db"
def __init__(self, port, replication):
super(DirectoryService, self).__init__()
self.port = port
self.replication = replication
self._create_tables()
self.server = Server(port, self._handler)
def _insert_server(self, sock, master, host, port):
exists = self._server_exists(host, port)
if exists:
return True
else:
self.execute_sql("insert into servers (master, host, port) values (?, ?, ?)", (master, host, port), exclusive=True)
return True
def _delete_server(self, sock, host, port):
self.execute_sql("delete from servers where host=? and port=?", (host, port))
def _list_servers(self, sock):
# return (pickle.dumps(self.fetch_sql("select * from servers", ())), "PADDING")
pass
def _server_exists(self, host, port):
return len(self.fetch_sql("select * from servers where host=? and port=?", (host, port))) != 0
def _select_random_server(self):
return self.fetch_sql("select * from servers where id >= (abs(random()) % (SELECT max(id) FROM servers));", ())
def _select_server_by_id(self, id):
return self.fetch_sql("select * from servers where id=?", (str(id),))
def _select_server_master(self, host, port):
return self.fetch_sql("select id from servers where host=? and port=?", (host, port))
def _find_directory_host(self, file_name):
return self.fetch_sql("select * from directories where file=?", (file_name,))
def _insert_directory_host(self, directory, file_name, server_id):
self.execute_sql("insert into directories (directory, file, server_id) values (?, ?, ?)",
(directory, file_name, str(server_id)))
def _create_tables(self):
conn = sqlite3.connect(self.DATABASE)
cur = conn.cursor()
cur.executescript("""
create table if not exists servers(
id INTEGER PRIMARY KEY ASC,
master INTEGER,
host TEXT,
port TEXT
);
create table if not exists directories(
id INTEGER PRIMARY KEY ASC,
directory TEXT,
file TEXT,
server_id TEXT
);""")
def _handler(self, sock):
try:
data = sock.recv(1024)
msg = data.decode('utf-8')
msg = msg.replace('$', ' ')
if 'KILL_SERVICE' in msg:
exit()
elif msg[:6] == "INSERT":
temp = msg.split()
ip_port = temp[1].split(':')
master = temp[2]
self._insert_server(sock, master, ip_port[0], ip_port[1])
self.server.respond(sock, response200())
elif msg[:4] == "DELETE":
temp = msg.split()
ip_port = temp[1].split(':')
self._delete_server(sock, ip_port[0], ip_port[1])
self.server.respond(sock, response200())
elif msg[:3] == "GET":
temp = msg.split()
file_name = temp[1]
row = self._select_random_server()
file_dir = self._find_directory_host(file_name)
pdb.set_trace()
if file_dir is not None:
response = response200() + " " + row[0][2] + ":" + row[0][3] + " " + file_dir[0][1] + " " + str(file_dir[0][0])
self.server.respond(sock, response)
else:
self.server.respond(sock, response404())
elif msg[:4] == "LIST":
# TODO not complete, for replication
temp = msg.split()
#self._mkdir_handler(sock, temp[1])
elif msg[:3] == "ADD":
temp = msg.split()
ip_port = temp[1].split(':')
server_ids = self._select_server_master(ip_port[0], ip_port[1])
server_id = server_ids[0]
self._insert_directory_host(temp[2], temp[3], server_id[0])
else:
self.server.error(sock, 0, responseErrParse())
except sock.error as e:
err = e.args[0]
self.server.error(sock, 0, e.args[1])
class FileService(object):
"""docstring for FileService"""
def __init__(self, port, ds_host, ds_port):
super(FileService, self).__init__()
self.dir = ''
self.port = port
self.ds_host = ds_host
self.ds_port = ds_port
self.server = Server(port, self._handler)
def announce_server(self):
sock = self.server.send_as_client(self.ds_host, self.ds_port, "INSERT " + self.server.host + ":" + str(self.port) + " " + "1")
data = sock.recv(1024)
if data.decode('utf-8') != response200():
print("Error with Directory Server: ", data)
sock.shutdown(socket.SHUT_WR)
sock.close()
#TODO Add to allow exsting files or remove
def _open_handler(self, conn, path):
filename = self.dir + path
if not os.path.isfile(filename):
self.server.error(conn, 404, response404())
else:
f = open(filename, "rb")
pdb.set_trace()
self.server.send_file(conn, f)
conn.shutdown(socket.SHUT_WR)
conn.close()
def _create_handler(self, conn, path):
file_path = os.path.dirname(path)
if not os.path.isdir(file_path):
self.server.error(conn, 405, response405())
else:
self.server.respond(conn, response200())
exists = os.path.isfile(self.dir + path)
f = open(self.dir + path, "wb")
conn.recv_file(f)
f.close()
self.server.respond(conn, response200())
# TODO: send to other replication managers
# if not exists:
#
def _mkdir_handler(self, conn, path):
newdir = str(self.dir + path.strip('/'))
basedir = os.path.dirname(newdir)
if not os.path.isdir(basedir):
self.server.error(conn, 404, response404())
else:
try:
os.makedirs(newdir)
self.server.respond(conn, response200())
# self._advertise_buffer.add(path.strip('/'), ObjectBuffer.Type.directory)
# TODO: send to replication manager
except Exception as e:
if e.errno != errno.EEXIST:
raise
else:
conn.send()
def _delete_handler(self, conn, path):
pdb.set_trace()
obj = str(self.dir + path).rstrip('/')
if os.path.isdir(obj):
shutil.rmtree(obj)
self.server.respond(conn, response200())
# self._advertise_buffer.add(path, ObjectBuffer.Type.deleteDirectory)
elif os.path.isfile(obj):
os.remove(obj)
self.server.respond(conn, response200())
# self._advertise_buffer.add(path, ObjectBuffer.Type.deleteFile)
else:
self.server.error(conn, 404, "not found!")
def _handler(self, sock):
LF = "\n"
try:
data = sock.recv(1024)
msg = data.decode('utf-8')
msg = msg.replace('$', ' ')
if 'KILL_SERVICE' in msg:
exit()
elif msg[:4] == "HELO":
response = ["IP:" + self.server.host, "Port:" + str(self.port), "StudentID:" + self.server.studentId]
fullResponse = msg + LF.join(response)
print(response)
sock.send(fullResponse.encode('utf-8'))
elif msg[:4] == "OPEN":
temp = msg.split()
self._open_handler(sock, temp[1])
elif msg[:6] == "CREATE":
temp = msg.split()
self._create_handler(sock, temp[1])
elif msg[:5] == "MKDIR":
temp = msg.split()
self._mkdir_handler(sock, temp[1])
elif msg[:6] == "DELETE":
temp = msg.split()
self._delete_handler(sock, temp[1])
else:
self.server.error(sock, 0, responseErrParse())
except sock.error as e:
err = e.args[0]
self.server.error(sock, 0, e.args[1])
class LockService(Database):
"""
LockService provdes functionality to lock access to a particular file on the fileservers.
Every service that writes to file uses the lockService, every read of a file checks if the particular file is locked.
The lockservice provides rudimentary acknowledgments on all operations
"""
DATABASE = "sql.db"
def __init__(self, port):
super(LockService, self).__init__()
self.port = port
self._create_tables()
self.server = Server(port, self._handler)
def _lock_file(self, file_name):
is_locked = self._check_if_locked(file_name)
if is_locked:
return False
insert = self.execute_sql("insert into locks (file_name) values (?)", (file_name,), exclusive=True)
if insert:
return True
else:
return False
def _unlock_file(self, file_name):
delete = self.execute_sql("delete from locks where file_name = ?", (file_name,), exclusive=True)
if delete:
return True
else:
return False
def _check_if_locked(self, file_name):
data = self.fetch_sql("select * from locks where file_name=?", (file_name,))
if file_name in data:
return True
else:
return False
def _handler(self, sock):
try:
data = sock.recv(1024)
msg = data.decode('utf-8')
msg = msg.replace('$', ' ')
if 'KILL_SERVICE' in msg:
exit()
elif msg[:4] == "LOCK":
temp = msg.split()
is_locked = self._unlock_file(temp[1])
if is_locked:
self.server.respond(sock, response200())
else:
self.server.respond(sock, response604())
elif msg[:6] == "UNLOCK":
temp = msg.split()
is_unlocked = self._unlock_file( temp[1])
if is_unlocked:
self.server.respond(sock, response200())
else:
self.server.respond(sock, response604())
elif msg[:5] == "CHECK":
temp = msg.split()
locked = self._check_if_locked(temp[1])
if locked:
self.server.respond(sock, responseLocked())
else:
self.server.respond(sock, responseUnlocked())
else:
self.server.error(sock, 0, responseErrParse())
except sock.error as e:
err = e.args[0]
self.server.error(sock, 0, e.args[1])
def _create_tables(self):
conn = sqlite3.connect(self.DATABASE)
cur = conn.cursor()
cur.executescript("""
create table if not exists locks(
id INTEGER PRIMARY KEY AUTOINCREMENT,
file_name TEXT
);""")
