def __init__(self, server):
self._server = server
self._connection = Connection(server)
def __init__(self, server):
self._server = server
self._connection = Connection(server)
class Client(object):
""" Memcached client implementation with simple get and set methods
Args:
server: Connection parameters
Provides socket and protocol implementation for get and set commands.
To leverage parallel execution use ClientPool class.
"""
def __init__(self, server):
self._server = server
self._connection = Connection(server)
def connect(self):
"""
Open socket connection to memcached instance
"""
return self._connection.open()
def disconnect(self):
"""
Close socket connection to memcached instance
"""
self._connection.close()
def get(self, key):
"""
Executes get command
:param key: Key of the value to get
:return: Value for given key
"""
if not self._connection.socket:
self._connection.open()
command = b'get' +\
b' ' + _encode(key) +\
Constants.END_LINE
try:
self._connection.send(command)
except Exception as ex:
log.error("Command failed: %s" % str(command), ex)
self._connection.close()
return None
try:
response = self._connection.read()
except Exception as ex:
log.error("Failed to read response from socket", ex)
self._connection.close()
return None
log.debug("Received from socket: %s" % response)
result = _parse_get_response(response)
_check_for_errors(result[0])
if len(result) > 2:
return result[1]
raise DriverUnknownException(
"Received unexpected response from the memcached instance %s" % str(result))
def set(self, key, value, expire=0, noreply=True):
"""
Executes set command
:param key: Key of the value to set
:param value: String value
:param expire: Expire time with default value of never (0)
:param noreply: Indicates if client should wait for response
:return: Returns indication of a successful write
Set method execution time can benefit from skipping wait for reply
"""
if not self._connection.socket:
self._connection.open()
if not isinstance(value, six.binary_type):
try:
value = _encode(value)
except UnicodeEncodeError as e:
raise DriverConversionException(
"Failed to convert value to binary with exception: %s" % str(e))
flags = 0
arguments = b''
if noreply:
arguments += b' noreply'
if expire > Constants.MAXIMUM_TTL:
log.info("Using a value of TTL larger than max ttl. \
The value provided will be converted into unix timestamp for ttl timeout")
command = b'set' +\
b' ' + _encode(key) +\
b' ' + _encode(flags) +\
b' ' + _encode(expire) +\
b' ' + _encode(len(value)) +\
arguments + Constants.END_LINE +\
value + Constants.END_LINE
try:
self._connection.send(command)
except Exception as ex:
log.error("Command failed: %s" % str(command), ex)
self._connection.close()
return False
if noreply:
return True
try:
response = self._connection.read()
except Exception as ex:
log.error("Failed to read response from socket", ex)
self._connection.close()
return False
result = response.rstrip(Constants.END_LINE).split(Constants.END_LINE)
log.debug("Received from socket: %s" % response)
if result[0] == StoreReply.STORED:
log.debug("Successfully stored data")
return True
elif result[0] == StoreReply.EXISTS:
log.debug("Entry already exists")
return False
elif result[0] == StoreReply.NOT_STORED:
log.warn("Entry not stored for some reason")
return False
elif result[0] == StoreReply.NOT_FOUND:
log.warn("Received not found response")
return False
_check_for_errors(result[0])
raise DriverUnknownException(
"Received unexpected response from the memcached instance %s" % str(response))
class Client(object):
""" Memcached client implementation with simple get and set methods
Args:
server: Connection parameters
Provides socket and protocol implementation for get and set commands.
To leverage parallel execution use ClientPool class.
"""
def __init__(self, server):
self._server = server
self._connection = Connection(server)
def connect(self):
"""
Open socket connection to memcached instance
"""
return self._connection.open()
def disconnect(self):
"""
Close socket connection to memcached instance
"""
self._connection.close()
def get(self, key):
"""
Executes get command
:param key: Key of the value to get
:return: Value for given key
"""
if not self._connection.socket:
self._connection.open()
command = b'get' +\
b' ' + _encode(key) +\
Constants.END_LINE
try:
self._connection.send(command)
except Exception as ex:
log.error("Command failed: %s" % str(command), ex)
self._connection.close()
return None
try:
response = self._connection.read()
except Exception as ex:
log.error("Failed to read response from socket", ex)
self._connection.close()
return None
log.debug("Received from socket: %s" % response)
result = _parse_get_response(response)
_check_for_errors(result[0])
if len(result) > 2:
return result[1]
raise DriverUnknownException(
"Received unexpected response from the memcached instance %s" %
str(result))
def set(self, key, value, expire=0, noreply=True):
"""
Executes set command
:param key: Key of the value to set
:param value: String value
:param expire: Expire time with default value of never (0)
:param noreply: Indicates if client should wait for response
:return: Returns indication of a successful write
Set method execution time can benefit from skipping wait for reply
"""
if not self._connection.socket:
self._connection.open()
if not isinstance(value, six.binary_type):
try:
value = _encode(value)
except UnicodeEncodeError as e:
raise DriverConversionException(
"Failed to convert value to binary with exception: %s" %
str(e))
flags = 0
arguments = b''
if noreply:
arguments += b' noreply'
if expire > Constants.MAXIMUM_TTL:
log.info("Using a value of TTL larger than max ttl. \
The value provided will be converted into unix timestamp for ttl timeout"
)
command = b'set' +\
b' ' + _encode(key) +\
b' ' + _encode(flags) +\
b' ' + _encode(expire) +\
b' ' + _encode(len(value)) +\
arguments + Constants.END_LINE +\
value + Constants.END_LINE
try:
self._connection.send(command)
except Exception as ex:
log.error("Command failed: %s" % str(command), ex)
self._connection.close()
return False
if noreply:
return True
try:
response = self._connection.read()
except Exception as ex:
log.error("Failed to read response from socket", ex)
self._connection.close()
return False
result = response.rstrip(Constants.END_LINE).split(Constants.END_LINE)
log.debug("Received from socket: %s" % response)
if result[0] == StoreReply.STORED:
log.debug("Successfully stored data")
return True
elif result[0] == StoreReply.EXISTS:
log.debug("Entry already exists")
return False
elif result[0] == StoreReply.NOT_STORED:
log.warn("Entry not stored for some reason")
return False
elif result[0] == StoreReply.NOT_FOUND:
log.warn("Received not found response")
return False
_check_for_errors(result[0])
raise DriverUnknownException(
"Received unexpected response from the memcached instance %s" %
str(response))
