def write_file(file_path, text):
"""
Write some text into a temporary file, creating its directory as needed, and
then atomically move to target location.
:param str file_path: the path to the file.
:param str text: the file content.
:raises:
lib.errors.SCIONIOError: IO error occurred
"""
# ":" is an illegal filename char on both windows and OSX, so disallow it globally to prevent
# incompatibility.
assert ":" not in file_path, file_path
dir_ = os.path.dirname(file_path)
try:
os.makedirs(dir_, exist_ok=True)
except OSError as e:
raise SCIONIOError("Error creating '%s' dir: %s" %
(dir_, e.strerror)) from None
tmp_file = file_path + ".new"
try:
with open(tmp_file, 'w') as f:
f.write(text)
except OSError as e:
raise SCIONIOError("Error creating/writing to temp file '%s': %s" %
(file_path, e.strerror)) from None
try:
os.rename(tmp_file, file_path)
except OSError as e:
raise SCIONIOError("Error moving '%s' to '%s': %s" %
(tmp_file, file_path, e.strerror)) from None
def copy_file(src, dst):
dst_dir = os.path.dirname(dst)
try:
os.makedirs(dst_dir, exist_ok=True)
except OSError as e:
raise SCIONIOError("Error creating dir '%s': %s" %
(dst_dir, e.strerror)) from None
try:
shutil.copyfile(src, dst)
except OSError as e:
raise SCIONIOError("Error copying '%s' to '%s': %s" %
(src, dst, e.strerror)) from None
def recv(self, block=True):
"""
Read data from socket.
:returns: bytestring containing received data.
"""
flags = 0
if not block:
flags = MSG_DONTWAIT
buf = recv_all(self.sock, self.COOKIE_LEN + 5, flags)
if not buf:
return None, None
cookie, addr_type, packet_len = struct.unpack("!8sBI", buf)
if cookie != self.COOKIE:
raise SCIONIOError("Dispatcher socket out of sync")
port_len = 0
if addr_type != AddrType.NONE:
port_len = 2
addr_len = haddr_get_type(addr_type).LEN
# We know there is data coming, block here to avoid sync problems.
buf = recv_all(self.sock, addr_len + port_len + packet_len, 0)
if addr_len > 0:
addr = buf[:addr_len]
port = struct.unpack("!H", buf[addr_len:addr_len + port_len])
sender = (str(ipaddress.ip_address(addr)), port)
else:
addr = ""
port = 0
sender = (None, None)
packet = buf[addr_len + port_len:]
return packet, sender
def read_file(file_path):
"""
Read and return contents of a file.
:param str file_path: the path to the file.
:returns: the file's contents.
:rtype: str
:raises:
lib.errors.SCIONIOError: error opening/reading from file.
"""
try:
with open(file_path) as file_handler:
return file_handler.read()
except OSError as e:
raise SCIONIOError("Unable to open '%s': %s" %
(file_path, e.strerror)) from None
def load_yaml_file(file_path):
"""
Read and parse a YAML config file.
:param str file_path: the path to the file.
:returns: YAML data
:rtype: dict
:raises:
lib.errors.SCIONIOError: error opening/reading from file.
lib.errors.SCIONYAMLError: error parsing file.
"""
try:
with open(file_path) as f:
return yaml.load(f)
except OSError as e:
raise SCIONIOError("Error opening '%s': %s" %
(file_path, e.strerror)) from None
except (yaml.scanner.ScannerError) as e:
raise SCIONYAMLError("Error parsing '%s': %s" %
(file_path, e)) from None
def load_json_file(file_path):
"""
Read and parse a JSON config file.
:param str file_path: the path to the file.
:returns: JSON data
:rtype: dict
:raises:
lib.errors.SCIONIOError: error opening/reading from file.
lib.errors.SCIONJSONError: error parsing file.
"""
try:
with open(file_path) as f:
return json.load(f)
except OSError as e:
raise SCIONIOError("Error opening '%s': %s" %
(file_path, e.strerror)) from None
except (ValueError, KeyError, TypeError) as e:
raise SCIONJSONError("Error parsing '%s': %s" %
(file_path, e)) from None