redict/client-libraries/python/redis.py
2009-03-24 14:30:04 +01:00

936 lines
25 KiB
Python

#!/usr/bin/python
""" redis.py - A client for the Redis daemon.
"""
__author__ = "Ludovico Magnocavallo <ludo\x40qix\x2eit>"
__copyright__ = "Copyright 2009, Ludovico Magnocavallo"
__license__ = "MIT"
__version__ = "0.5"
__revision__ = "$LastChangedRevision: 175 $"[22:-2]
__date__ = "$LastChangedDate: 2009-03-17 16:15:55 +0100 (Mar, 17 Mar 2009) $"[18:-2]
# TODO: Redis._get_multi_response
import socket
BUFSIZE = 4096
class RedisError(Exception): pass
class ConnectionError(RedisError): pass
class ResponseError(RedisError): pass
class InvalidResponse(RedisError): pass
class InvalidData(RedisError): pass
class Redis(object):
"""The main Redis client.
"""
def __init__(self, host=None, port=None, timeout=None):
self.host = host or 'localhost'
self.port = port or 6379
if timeout:
socket.setdefaulttimeout(timeout)
self._sock = None
self._fp = None
def _write(self, s):
"""
>>> r = Redis()
>>> r.connect()
>>> r._sock.close()
>>> try:
... r._write('pippo')
... except ConnectionError, e:
... print e
Error 9 while writing to socket. Bad file descriptor.
>>>
>>>
"""
try:
self._sock.sendall(s)
except socket.error, e:
if e.args[0] == 32:
# broken pipe
self.disconnect()
raise ConnectionError("Error %s while writing to socket. %s." % tuple(e.args))
def _read(self):
try:
return self._fp.readline()
except socket.error, e:
if e.args and e.args[0] == errno.EAGAIN:
return
self.disconnect()
raise ConnectionError("Error %s while reading from socket. %s." % tuple(e.args))
if not data:
self.disconnect()
raise ConnectionError("Socket connection closed when reading.")
return data
def ping(self):
"""
>>> r = Redis()
>>> r.ping()
'PONG'
>>>
"""
self.connect()
self._write('PING\r\n')
return self.get_response()
def set(self, name, value, preserve=False):
"""
>>> r = Redis()
>>> r.set('a', 'pippo')
'OK'
>>> try:
... r.set('a', u'pippo \u3235')
... except InvalidData, e:
... print e
Error encoding unicode value for key 'a': 'ascii' codec can't encode character u'\u3235' in position 15: ordinal not in range(128).
>>> r.set('b', 105.2)
'OK'
>>> r.set('b', 'xxx', preserve=True)
0
>>> r.get('b')
'105.2'
>>>
"""
self.connect()
# the following will raise an error for unicode values that can't be encoded to ascii
# we could probably add an 'encoding' arg to init, but then what do we do with get()?
# convert back to unicode? and what about ints, or pickled values?
try:
value = value if isinstance(value, basestring) else str(value)
self._write('%s %s %s\r\n%s\r\n' % (
'SETNX' if preserve else 'SET', name, len(value), value
))
except UnicodeEncodeError, e:
raise InvalidData("Error encoding unicode value for key '%s': %s." % (name, e))
return self.get_response()
def get(self, name):
"""
>>> r = Redis()
>>> r.set('a', 'pippo'), r.set('b', 15), r.set('c', '\\r\\naaa\\nbbb\\r\\ncccc\\nddd\\r\\n'), r.set('d', '\\r\\n')
('OK', 'OK', 'OK', 'OK')
>>> r.get('a')
'pippo'
>>> r.get('b')
'15'
>>> r.get('d')
'\\r\\n'
>>> r.get('b')
'15'
>>> r.get('c')
'\\r\\naaa\\nbbb\\r\\ncccc\\nddd\\r\\n'
>>> r.get('c')
'\\r\\naaa\\nbbb\\r\\ncccc\\nddd\\r\\n'
>>> r.get('ajhsd')
>>>
"""
self.connect()
self._write('GET %s\r\n' % name)
return self.get_response()
def mget(self, *args):
"""
>>> r = Redis()
>>> r.set('a', 'pippo'), r.set('b', 15), r.set('c', '\\r\\naaa\\nbbb\\r\\ncccc\\nddd\\r\\n'), r.set('d', '\\r\\n')
('OK', 'OK', 'OK', 'OK')
>>> r.mget('a', 'b', 'c', 'd')
['pippo', '15', '\\r\\naaa\\nbbb\\r\\ncccc\\nddd\\r\\n', '\\r\\n']
>>>
"""
self.connect()
self._write('MGET %s\r\n' % ' '.join(args))
return self.get_response()
def incr(self, name, amount=1):
"""
>>> r = Redis()
>>> r.delete('a')
1
>>> r.incr('a')
1
>>> r.incr('a')
2
>>> r.incr('a', 2)
4
>>>
"""
self.connect()
if amount == 1:
self._write('INCR %s\r\n' % name)
else:
self._write('INCRBY %s %s\r\n' % (name, amount))
return self.get_response()
def decr(self, name, amount=1):
"""
>>> r = Redis()
>>> if r.get('a'):
... r.delete('a')
... else:
... print 1
1
>>> r.decr('a')
-1
>>> r.decr('a')
-2
>>> r.decr('a', 5)
-7
>>>
"""
self.connect()
if amount == 1:
self._write('DECR %s\r\n' % name)
else:
self._write('DECRBY %s %s\r\n' % (name, amount))
return self.get_response()
def exists(self, name):
"""
>>> r = Redis()
>>> r.exists('dsjhfksjdhfkdsjfh')
0
>>> r.set('a', 'a')
'OK'
>>> r.exists('a')
1
>>>
"""
self.connect()
self._write('EXISTS %s\r\n' % name)
return self.get_response()
def delete(self, name):
"""
>>> r = Redis()
>>> r.delete('dsjhfksjdhfkdsjfh')
0
>>> r.set('a', 'a')
'OK'
>>> r.delete('a')
1
>>> r.exists('a')
0
>>> r.delete('a')
0
>>>
"""
self.connect()
self._write('DEL %s\r\n' % name)
return self.get_response()
def key_type(self, name):
"""
Not yet implemented.
"""
self.connect()
self._write('TYPE %s\r\n' % name)
return self.get_response()
def keys(self, pattern):
"""
>>> r = Redis()
>>> r.flush()
'OK'
>>> r.set('a', 'a')
'OK'
>>> r.keys('a*')
['a']
>>> r.set('a2', 'a')
'OK'
>>> r.keys('a*')
['a', 'a2']
>>> r.delete('a2')
1
>>> r.keys('sjdfhskjh*')
[]
>>>
"""
self.connect()
self._write('KEYS %s\r\n' % pattern)
return self.get_response().split()
def randomkey(self):
"""
>>> r = Redis()
>>> r.set('a', 'a')
'OK'
>>> isinstance(r.randomkey(), str)
True
>>>
"""
#raise NotImplementedError("Implemented but buggy, do not use.")
self.connect()
self._write('RANDOMKEY\r\n')
return self.get_response()
def rename(self, src, dst, preserve=False):
"""
>>> r = Redis()
>>> try:
... r.rename('a', 'a')
... except ResponseError, e:
... print e
source and destination objects are the same
>>> r.rename('a', 'b')
'OK'
>>> try:
... r.rename('a', 'b')
... except ResponseError, e:
... print e
no such key
>>> r.set('a', 1)
'OK'
>>> r.rename('b', 'a', preserve=True)
0
>>>
"""
self.connect()
if preserve:
self._write('RENAMENX %s %s\r\n' % (src, dst))
return self.get_response()
else:
self._write('RENAME %s %s\r\n' % (src, dst))
return self.get_response().strip()
def push(self, name, value, tail=False):
"""
>>> r = Redis()
>>> r.delete('l')
1
>>> r.push('l', 'a')
'OK'
>>> r.set('a', 'a')
'OK'
>>> try:
... r.push('a', 'a')
... except ResponseError, e:
... print e
Operation against a key holding the wrong kind of value
>>>
"""
self.connect()
# same considerations on unicode as in set() apply here
try:
value = value if isinstance(value, basestring) else str(value)
self._write('%s %s %s\r\n%s\r\n' % (
'LPUSH' if tail else 'RPUSH', name, len(value), value
))
except UnicodeEncodeError, e:
raise InvalidData("Error encoding unicode value for element in list '%s': %s." % (name, e))
return self.get_response()
def llen(self, name):
"""
>>> r = Redis()
>>> r.delete('l')
1
>>> r.push('l', 'a')
'OK'
>>> r.llen('l')
1
>>> r.push('l', 'a')
'OK'
>>> r.llen('l')
2
>>>
"""
self.connect()
self._write('LLEN %s\r\n' % name)
return self.get_response()
def lrange(self, name, start, end):
"""
>>> r = Redis()
>>> r.delete('l')
1
>>> r.lrange('l', 0, 1)
[]
>>> r.push('l', 'aaa')
'OK'
>>> r.lrange('l', 0, 1)
['aaa']
>>> r.push('l', 'bbb')
'OK'
>>> r.lrange('l', 0, 0)
['aaa']
>>> r.lrange('l', 0, 1)
['aaa', 'bbb']
>>> r.lrange('l', -1, 0)
[]
>>> r.lrange('l', -1, -1)
['bbb']
>>>
"""
self.connect()
self._write('LRANGE %s %s %s\r\n' % (name, start, end))
return self.get_response()
def ltrim(self, name, start, end):
"""
>>> r = Redis()
>>> r.delete('l')
1
>>> try:
... r.ltrim('l', 0, 1)
... except ResponseError, e:
... print e
no such key
>>> r.push('l', 'aaa')
'OK'
>>> r.push('l', 'bbb')
'OK'
>>> r.push('l', 'ccc')
'OK'
>>> r.ltrim('l', 0, 1)
'OK'
>>> r.llen('l')
2
>>> r.ltrim('l', 99, 95)
'OK'
>>> r.llen('l')
0
>>>
"""
self.connect()
self._write('LTRIM %s %s %s\r\n' % (name, start, end))
return self.get_response()
def lindex(self, name, index):
"""
>>> r = Redis()
>>> res = r.delete('l')
>>> r.lindex('l', 0)
>>> r.push('l', 'aaa')
'OK'
>>> r.lindex('l', 0)
'aaa'
>>> r.lindex('l', 2)
>>> r.push('l', 'ccc')
'OK'
>>> r.lindex('l', 1)
'ccc'
>>> r.lindex('l', -1)
'ccc'
>>>
"""
self.connect()
self._write('LINDEX %s %s\r\n' % (name, index))
return self.get_response()
def pop(self, name, tail=False):
"""
>>> r = Redis()
>>> r.delete('l')
1
>>> r.pop('l')
>>> r.push('l', 'aaa')
'OK'
>>> r.push('l', 'bbb')
'OK'
>>> r.pop('l')
'aaa'
>>> r.pop('l')
'bbb'
>>> r.pop('l')
>>> r.push('l', 'aaa')
'OK'
>>> r.push('l', 'bbb')
'OK'
>>> r.pop('l', tail=True)
'bbb'
>>> r.pop('l')
'aaa'
>>> r.pop('l')
>>>
"""
self.connect()
self._write('%s %s\r\n' % ('RPOP' if tail else 'LPOP', name))
return self.get_response()
def lset(self, name, index, value):
"""
>>> r = Redis()
>>> r.delete('l')
1
>>> try:
... r.lset('l', 0, 'a')
... except ResponseError, e:
... print e
no such key
>>> r.push('l', 'aaa')
'OK'
>>> try:
... r.lset('l', 1, 'a')
... except ResponseError, e:
... print e
index out of range
>>> r.lset('l', 0, 'bbb')
'OK'
>>> r.lrange('l', 0, 1)
['bbb']
>>>
"""
self.connect()
try:
value = value if isinstance(value, basestring) else str(value)
self._write('LSET %s %s %s\r\n%s\r\n' % (
name, index, len(value), value
))
except UnicodeEncodeError, e:
raise InvalidData("Error encoding unicode value for element %s in list '%s': %s." % (index, name, e))
return self.get_response()
def lrem(self, name, value, num=0):
"""
>>> r = Redis()
>>> r.delete('l')
1
>>> r.push('l', 'aaa')
'OK'
>>> r.push('l', 'bbb')
'OK'
>>> r.push('l', 'aaa')
'OK'
>>> r.lrem('l', 'aaa')
2
>>> r.lrange('l', 0, 10)
['bbb']
>>> r.push('l', 'aaa')
'OK'
>>> r.push('l', 'aaa')
'OK'
>>> r.lrem('l', 'aaa', 1)
1
>>> r.lrem('l', 'aaa', 1)
1
>>> r.lrem('l', 'aaa', 1)
0
>>>
"""
self.connect()
try:
value = value if isinstance(value, basestring) else str(value)
self._write('LREM %s %s %s\r\n%s\r\n' % (
name, num, len(value), value
))
except UnicodeEncodeError, e:
raise InvalidData("Error encoding unicode value for element %s in list '%s': %s." % (index, name, e))
return self.get_response()
def sort(self, name, by=None, get=None, start=None, num=None, desc=False, alpha=False):
"""
>>> r = Redis()
>>> r.delete('l')
1
>>> r.push('l', 'ccc')
'OK'
>>> r.push('l', 'aaa')
'OK'
>>> r.push('l', 'ddd')
'OK'
>>> r.push('l', 'bbb')
'OK'
>>> r.sort('l', alpha=True)
['aaa', 'bbb', 'ccc', 'ddd']
>>> r.delete('l')
1
>>> for i in range(1, 5):
... res = r.push('l', 1.0 / i)
>>> r.sort('l')
['0.25', '0.333333333333', '0.5', '1.0']
>>> r.sort('l', desc=True)
['1.0', '0.5', '0.333333333333', '0.25']
>>> r.sort('l', desc=True, start=2, num=1)
['0.333333333333']
>>> r.set('weight_0.5', 10)
'OK'
>>> r.sort('l', desc=True, by='weight_*')
['0.5', '1.0', '0.333333333333', '0.25']
>>> for i in r.sort('l', desc=True):
... res = r.set('test_%s' % i, 100 - float(i))
>>> r.sort('l', desc=True, get='test_*')
['99.0', '99.5', '99.6666666667', '99.75']
>>> r.sort('l', desc=True, by='weight_*', get='test_*')
['99.5', '99.0', '99.6666666667', '99.75']
>>> r.sort('l', desc=True, by='weight_*', get='missing_*')
[None, None, None, None]
>>>
"""
stmt = ['SORT', name]
if by:
stmt.append("BY %s" % by)
if start and num:
stmt.append("LIMIT %s %s" % (start, num))
if get is None:
pass
elif isinstance(get, basestring):
stmt.append("GET %s" % get)
elif isinstance(get, list) or isinstance(get, tuple):
for g in get:
stmt.append("GET %s" % g)
else:
raise RedisError("Invalid parameter 'get' for Redis sort")
if desc:
stmt.append("DESC")
if alpha:
stmt.append("ALPHA")
self.connect()
self._write(' '.join(stmt + ["\r\n"]))
return self.get_response()
def sadd(self, name, value):
"""
>>> r = Redis()
>>> res = r.delete('s')
>>> r.sadd('s', 'a')
1
>>> r.sadd('s', 'b')
1
>>>
"""
self.connect()
# same considerations on unicode as in set() apply here
try:
value = value if isinstance(value, basestring) else str(value)
self._write('SADD %s %s\r\n%s\r\n' % (
name, len(value), value
))
except UnicodeEncodeError, e:
raise InvalidData("Error encoding unicode value for element in set '%s': %s." % (name, e))
return self.get_response()
def srem(self, name, value):
"""
>>> r = Redis()
>>> r.delete('s')
1
>>> r.srem('s', 'aaa')
0
>>> r.sadd('s', 'b')
1
>>> r.srem('s', 'b')
1
>>> r.sismember('s', 'b')
0
>>>
"""
self.connect()
# same considerations on unicode as in set() apply here
try:
value = value if isinstance(value, basestring) else str(value)
self._write('SREM %s %s\r\n%s\r\n' % (
name, len(value), value
))
except UnicodeEncodeError, e:
raise InvalidData("Error encoding unicode value for element in set '%s': %s." % (name, e))
return self.get_response()
def sismember(self, name, value):
"""
>>> r = Redis()
>>> r.delete('s')
1
>>> r.sismember('s', 'b')
0
>>> r.sadd('s', 'a')
1
>>> r.sismember('s', 'b')
0
>>> r.sismember('s', 'a')
1
>>>
"""
self.connect()
# same considerations on unicode as in set() apply here
try:
value = value if isinstance(value, basestring) else str(value)
self._write('SISMEMBER %s %s\r\n%s\r\n' % (
name, len(value), value
))
except UnicodeEncodeError, e:
raise InvalidData("Error encoding unicode value for element in set '%s': %s." % (name, e))
return self.get_response()
def sinter(self, *args):
"""
>>> r = Redis()
>>> res = r.delete('s1')
>>> res = r.delete('s2')
>>> res = r.delete('s3')
>>> r.sadd('s1', 'a')
1
>>> r.sadd('s2', 'a')
1
>>> r.sadd('s3', 'b')
1
>>> try:
... r.sinter()
... except ResponseError, e:
... print e
wrong number of arguments
>>> try:
... r.sinter('l')
... except ResponseError, e:
... print e
Operation against a key holding the wrong kind of value
>>> r.sinter('s1', 's2', 's3')
set([])
>>> r.sinter('s1', 's2')
set(['a'])
>>>
"""
self.connect()
self._write('SINTER %s\r\n' % ' '.join(args))
return set(self.get_response())
def sinterstore(self, dest, *args):
"""
>>> r = Redis()
>>> res = r.delete('s1')
>>> res = r.delete('s2')
>>> res = r.delete('s3')
>>> r.sadd('s1', 'a')
1
>>> r.sadd('s2', 'a')
1
>>> r.sadd('s3', 'b')
1
>>> r.sinterstore('s_s', 's1', 's2', 's3')
'OK'
>>> r.sinterstore('s_s', 's1', 's2')
'OK'
>>> r.smembers('s_s')
set(['a'])
>>>
"""
self.connect()
self._write('SINTERSTORE %s %s\r\n' % (dest, ' '.join(args)))
return self.get_response()
def smembers(self, name):
"""
>>> r = Redis()
>>> r.delete('s')
1
>>> r.sadd('s', 'a')
1
>>> r.sadd('s', 'b')
1
>>> try:
... r.smembers('l')
... except ResponseError, e:
... print e
Operation against a key holding the wrong kind of value
>>> r.smembers('s')
set(['a', 'b'])
>>>
"""
self.connect()
self._write('SMEMBERS %s\r\n' % name)
return set(self.get_response())
def select(self, db):
"""
>>> r = Redis()
>>> r.delete('a')
1
>>> r.select(1)
'OK'
>>> r.set('a', 1)
'OK'
>>> r.select(0)
'OK'
>>> r.get('a')
>>>
"""
self.connect()
self._write('SELECT %s\r\n' % db)
return self.get_response()
def move(self, name, db):
"""
>>> r = Redis()
>>> r.select(0)
'OK'
>>> r.set('a', 'a')
'OK'
>>> r.select(1)
'OK'
>>> if r.get('a'):
... r.delete('a')
... else:
... print 1
1
>>> r.select(0)
'OK'
>>> r.move('a', 1)
1
>>> r.get('a')
>>> r.select(1)
'OK'
>>> r.get('a')
'a'
>>> r.select(0)
'OK'
>>>
"""
self.connect()
self._write('MOVE %s %s\r\n' % (name, db))
return self.get_response()
def save(self, background=False):
"""
>>> r = Redis()
>>> r.save()
'OK'
>>> try:
... resp = r.save(background=True)
... except ResponseError, e:
... assert str(e) == 'background save already in progress', str(e)
... else:
... assert resp == 'OK'
>>>
"""
self.connect()
if background:
self._write('BGSAVE\r\n')
else:
self._write('SAVE\r\n')
return self.get_response()
def lastsave(self):
"""
>>> import time
>>> r = Redis()
>>> t = int(time.time())
>>> r.save()
'OK'
>>> r.lastsave() >= t
True
>>>
"""
self.connect()
self._write('LASTSAVE\r\n')
return self.get_response()
def flush(self, all_dbs=False):
"""
>>> r = Redis()
>>> r.flush()
'OK'
>>> r.flush(all_dbs=True)
'OK'
>>>
"""
self.connect()
self._write('%s\r\n' % ('FLUSHALL' if all_dbs else 'FLUSHDB'))
return self.get_response()
def info(self):
"""
>>> r = Redis()
>>> info = r.info()
>>> info and isinstance(info, dict)
True
>>> isinstance(info.get('connected_clients'), int)
True
>>>
"""
self.connect()
self._write('INFO\r\n')
info = dict()
for l in self.get_response().split('\r\n'):
if not l:
continue
k, v = l.split(':', 1)
info[k] = int(v) if v.isdigit() else v
return info
def get_response(self):
data = self._read().strip()
c = data[0]
if c == '-':
raise ResponseError(data[5:] if data[:5] == '-ERR ' else data[1:])
if c == '+':
return data[1:]
if c == '*':
try:
num = int(data[1:])
except (TypeError, ValueError):
raise InvalidResponse("Cannot convert multi-response header '%s' to integer" % data)
result = list()
for i in range(num):
result.append(self._get_value())
return result
return self._get_value(data)
def _get_value(self, data=None):
data = data or self._read().strip()
if data == '$-1':
return None
try:
c, i = data[0], (int(data[1:]) if data.find('.') == -1 else float(data[1:]))
except ValueError:
raise InvalidResponse("Cannot convert data '%s' to integer" % data)
if c == ':':
return i
if c != '$':
raise InvalidResponse("Unkown response prefix for '%s'" % data)
buf = []
while i > 0:
data = self._read()
i -= len(data)
if len(data) > i:
# we got the ending crlf
data = data.rstrip()
buf.append(data)
if i == 0:
# the data has a trailing crlf embedded, let's restore it
buf.append(self._read())
return ''.join(buf)
def disconnect(self):
if isinstance(self._sock, socket.socket):
try:
self._sock.close()
except socket.error:
pass
self._sock = None
self._fp = None
def connect(self):
"""
>>> r = Redis()
>>> r.connect()
>>> isinstance(r._sock, socket.socket)
True
>>>
"""
if isinstance(self._sock, socket.socket):
return
try:
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect((self.host, self.port))
except socket.error, e:
raise ConnectionError("Error %s connecting to %s:%s. %s." % (e.args[0], self.host, self.port, e.args[1]))
else:
self._sock = sock
self._fp = self._sock.makefile('r')
if __name__ == '__main__':
import doctest
doctest.testmod()