/usr/lib/python2.7/dist-packages/redis/connection.py is in python-redis 2.7.2-1build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 | from itertools import chain
import os
import socket
import sys
from redis._compat import (b, xrange, imap, byte_to_chr, unicode, bytes, long,
BytesIO, nativestr, basestring)
from redis.exceptions import (
RedisError,
ConnectionError,
ResponseError,
InvalidResponse,
AuthenticationError,
NoScriptError,
ExecAbortError,
)
try:
import hiredis
hiredis_available = True
except ImportError:
hiredis_available = False
SYM_STAR = b('*')
SYM_DOLLAR = b('$')
SYM_CRLF = b('\r\n')
SYM_LF = b('\n')
class PythonParser(object):
"Plain Python parsing class"
MAX_READ_LENGTH = 1000000
encoding = None
EXCEPTION_CLASSES = {
'ERR': ResponseError,
'NOSCRIPT': NoScriptError,
'EXECABORT': ExecAbortError,
}
def __init__(self):
self._fp = None
def __del__(self):
try:
self.on_disconnect()
except:
pass
def on_connect(self, connection):
"Called when the socket connects"
self._fp = connection._sock.makefile('rb')
if connection.decode_responses:
self.encoding = connection.encoding
def on_disconnect(self):
"Called when the socket disconnects"
if self._fp is not None:
self._fp.close()
self._fp = None
def read(self, length=None):
"""
Read a line from the socket is no length is specified,
otherwise read ``length`` bytes. Always strip away the newlines.
"""
try:
if length is not None:
bytes_left = length + 2 # read the line ending
if length > self.MAX_READ_LENGTH:
# apparently reading more than 1MB or so from a windows
# socket can cause MemoryErrors. See:
# https://github.com/andymccurdy/redis-py/issues/205
# read smaller chunks at a time to work around this
try:
buf = BytesIO()
while bytes_left > 0:
read_len = min(bytes_left, self.MAX_READ_LENGTH)
buf.write(self._fp.read(read_len))
bytes_left -= read_len
buf.seek(0)
return buf.read(length)
finally:
buf.close()
return self._fp.read(bytes_left)[:-2]
# no length, read a full line
return self._fp.readline()[:-2]
except (socket.error, socket.timeout):
e = sys.exc_info()[1]
raise ConnectionError("Error while reading from socket: %s" %
(e.args,))
def parse_error(self, response):
"Parse an error response"
error_code = response.split(' ')[0]
if error_code in self.EXCEPTION_CLASSES:
response = response[len(error_code) + 1:]
return self.EXCEPTION_CLASSES[error_code](response)
return ResponseError(response)
def read_response(self):
response = self.read()
if not response:
raise ConnectionError("Socket closed on remote end")
byte, response = byte_to_chr(response[0]), response[1:]
if byte not in ('-', '+', ':', '$', '*'):
raise InvalidResponse("Protocol Error")
# server returned an error
if byte == '-':
response = nativestr(response)
if response.startswith('LOADING '):
# if we're loading the dataset into memory, kill the socket
# so we re-initialize (and re-SELECT) next time.
raise ConnectionError("Redis is loading data into memory")
# *return*, not raise the exception class. if it is meant to be
# raised, it will be at a higher level.
return self.parse_error(response)
# single value
elif byte == '+':
pass
# int value
elif byte == ':':
response = long(response)
# bulk response
elif byte == '$':
length = int(response)
if length == -1:
return None
response = self.read(length)
# multi-bulk response
elif byte == '*':
length = int(response)
if length == -1:
return None
response = [self.read_response() for i in xrange(length)]
if isinstance(response, bytes) and self.encoding:
response = response.decode(self.encoding)
return response
class HiredisParser(object):
"Parser class for connections using Hiredis"
def __init__(self):
if not hiredis_available:
raise RedisError("Hiredis is not installed")
def __del__(self):
try:
self.on_disconnect()
except:
pass
def on_connect(self, connection):
self._sock = connection._sock
kwargs = {
'protocolError': InvalidResponse,
'replyError': ResponseError,
}
if connection.decode_responses:
kwargs['encoding'] = connection.encoding
self._reader = hiredis.Reader(**kwargs)
def on_disconnect(self):
self._sock = None
self._reader = None
def read_response(self):
if not self._reader:
raise ConnectionError("Socket closed on remote end")
response = self._reader.gets()
while response is False:
try:
buffer = self._sock.recv(4096)
except (socket.error, socket.timeout):
e = sys.exc_info()[1]
raise ConnectionError("Error while reading from socket: %s" %
(e.args,))
if not buffer:
raise ConnectionError("Socket closed on remote end")
self._reader.feed(buffer)
# proactively, but not conclusively, check if more data is in the
# buffer. if the data received doesn't end with \n, there's more.
if not buffer.endswith(SYM_LF):
continue
response = self._reader.gets()
return response
if hiredis_available:
DefaultParser = HiredisParser
else:
DefaultParser = PythonParser
class Connection(object):
"Manages TCP communication to and from a Redis server"
def __init__(self, host='localhost', port=6379, db=0, password=None,
socket_timeout=None, encoding='utf-8',
encoding_errors='strict', decode_responses=False,
parser_class=DefaultParser):
self.pid = os.getpid()
self.host = host
self.port = port
self.db = db
self.password = password
self.socket_timeout = socket_timeout
self.encoding = encoding
self.encoding_errors = encoding_errors
self.decode_responses = decode_responses
self._sock = None
self._parser = parser_class()
def __del__(self):
try:
self.disconnect()
except:
pass
def connect(self):
"Connects to the Redis server if not already connected"
if self._sock:
return
try:
sock = self._connect()
except socket.error:
e = sys.exc_info()[1]
raise ConnectionError(self._error_message(e))
self._sock = sock
self.on_connect()
def _connect(self):
"Create a TCP socket connection"
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.settimeout(self.socket_timeout)
sock.connect((self.host, self.port))
return sock
def _error_message(self, exception):
# args for socket.error can either be (errno, "message")
# or just "message"
if len(exception.args) == 1:
return "Error connecting to %s:%s. %s." % \
(self.host, self.port, exception.args[0])
else:
return "Error %s connecting %s:%s. %s." % \
(exception.args[0], self.host, self.port, exception.args[1])
def on_connect(self):
"Initialize the connection, authenticate and select a database"
self._parser.on_connect(self)
# if a password is specified, authenticate
if self.password:
self.send_command('AUTH', self.password)
if nativestr(self.read_response()) != 'OK':
raise AuthenticationError('Invalid Password')
# if a database is specified, switch to it
if self.db:
self.send_command('SELECT', self.db)
if nativestr(self.read_response()) != 'OK':
raise ConnectionError('Invalid Database')
def disconnect(self):
"Disconnects from the Redis server"
self._parser.on_disconnect()
if self._sock is None:
return
try:
self._sock.close()
except socket.error:
pass
self._sock = None
def send_packed_command(self, command):
"Send an already packed command to the Redis server"
if not self._sock:
self.connect()
try:
self._sock.sendall(command)
except socket.error:
e = sys.exc_info()[1]
self.disconnect()
if len(e.args) == 1:
_errno, errmsg = 'UNKNOWN', e.args[0]
else:
_errno, errmsg = e.args
raise ConnectionError("Error %s while writing to socket. %s." %
(_errno, errmsg))
except:
self.disconnect()
raise
def send_command(self, *args):
"Pack and send a command to the Redis server"
self.send_packed_command(self.pack_command(*args))
def read_response(self):
"Read the response from a previously sent command"
try:
response = self._parser.read_response()
except:
self.disconnect()
raise
if isinstance(response, ResponseError):
raise response
return response
def encode(self, value):
"Return a bytestring representation of the value"
if isinstance(value, bytes):
return value
if isinstance(value, float):
value = repr(value)
if not isinstance(value, basestring):
value = str(value)
if isinstance(value, unicode):
value = value.encode(self.encoding, self.encoding_errors)
return value
def pack_command(self, *args):
"Pack a series of arguments into a value Redis command"
output = SYM_STAR + b(str(len(args))) + SYM_CRLF
for enc_value in imap(self.encode, args):
output += SYM_DOLLAR
output += b(str(len(enc_value)))
output += SYM_CRLF
output += enc_value
output += SYM_CRLF
return output
class UnixDomainSocketConnection(Connection):
def __init__(self, path='', db=0, password=None,
socket_timeout=None, encoding='utf-8',
encoding_errors='strict', decode_responses=False,
parser_class=DefaultParser):
self.pid = os.getpid()
self.path = path
self.db = db
self.password = password
self.socket_timeout = socket_timeout
self.encoding = encoding
self.encoding_errors = encoding_errors
self.decode_responses = decode_responses
self._sock = None
self._parser = parser_class()
def _connect(self):
"Create a Unix domain socket connection"
sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
sock.settimeout(self.socket_timeout)
sock.connect(self.path)
return sock
def _error_message(self, exception):
# args for socket.error can either be (errno, "message")
# or just "message"
if len(exception.args) == 1:
return "Error connecting to unix socket: %s. %s." % \
(self.path, exception.args[0])
else:
return "Error %s connecting to unix socket: %s. %s." % \
(exception.args[0], self.path, exception.args[1])
# TODO: add ability to block waiting on a connection to be released
class ConnectionPool(object):
"Generic connection pool"
def __init__(self, connection_class=Connection, max_connections=None,
**connection_kwargs):
self.pid = os.getpid()
self.connection_class = connection_class
self.connection_kwargs = connection_kwargs
self.max_connections = max_connections or 2 ** 31
self._created_connections = 0
self._available_connections = []
self._in_use_connections = set()
def _checkpid(self):
if self.pid != os.getpid():
self.disconnect()
self.__init__(self.connection_class, self.max_connections,
**self.connection_kwargs)
def get_connection(self, command_name, *keys, **options):
"Get a connection from the pool"
self._checkpid()
try:
connection = self._available_connections.pop()
except IndexError:
connection = self.make_connection()
self._in_use_connections.add(connection)
return connection
def make_connection(self):
"Create a new connection"
if self._created_connections >= self.max_connections:
raise ConnectionError("Too many connections")
self._created_connections += 1
return self.connection_class(**self.connection_kwargs)
def release(self, connection):
"Releases the connection back to the pool"
self._checkpid()
if connection.pid == self.pid:
self._in_use_connections.remove(connection)
self._available_connections.append(connection)
def disconnect(self):
"Disconnects all connections in the pool"
all_conns = chain(self._available_connections,
self._in_use_connections)
for connection in all_conns:
connection.disconnect()
|