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#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# Simple key-value datastore
# - support only mysql database
# - console support added
#
# some ideas taked from PyMongo interface http://api.mongodb.org/python/current/index.html
# kvlite2 tutorial http://code.google.com/p/kvlite/wiki/kvlite2
#
# TODO autocommit for put()
#
#
__author__ = 'Andrey Usov <http://devel.ownport.net>'
__version__ = '0.3'
__license__ = """
Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 'AS IS'
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE."""
import re
import cmd
import sys
import zlib
import pprint
import binascii
try:
import MySQLdb
except ImportError:
print >> sys.stderr, 'Error! MySQLdb package is not installed, please install python-mysqldb'
sys.exit()
from json import loads as json_decode
from json import dumps as json_encode
# TODO describe this Exception
class WronKeyValue(Exception): pass
# in case when URI for connection defined incorrectly this exception is raised
class WrongURIException(Exception): pass
# in case value cannot be unpacked
class ValueUnpackError(Exception): pass
# exception raised in case of connection error
class ConnectionError(Exception): pass
# -----------------------------------------------------------------
# KVLite tools
# -----------------------------------------------------------------
def parse_uri(uri):
''' parse URI
return driver, user, password, host, port, database, table
'''
result = {}
m = re.search(r'(?P<drv>\w+)://(?P<usr>.+):(?P<pwd>.+)@(?P<host>.+?):?(?P<port>\d*)\/(?P<db>.+)\.(?P<coll>.+)', uri, re.I)
try:
result = dict(m.groupdict())
except AttributeError,e:
raise WrongURIException(e)
if result['port'] <> '':
result['port'] = int(result['port'])
else:
result['port'] = 3306
return result
def create_collection(URI):
''' create collection '''
params = parse_uri(URI)
try:
conn = MySQLdb.connect(host=params['host'], port = params['port'],
user=params['usr'], passwd=params['pwd'], db=params['db'])
except MySQLdb.OperationalError,err:
raise ConnectionError(err)
cursor = conn.cursor()
SQL_CREATE_TABLE = '''CREATE TABLE IF NOT EXISTS %s (
__rowid__ INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
k BINARY(20) NOT NULL,
v MEDIUMBLOB,
UNIQUE KEY (k) ) ENGINE=InnoDB;'''
cursor.execute(SQL_CREATE_TABLE % params['coll'])
conn.commit()
def is_collection_exists(URI):
''' check if collection exists '''
params = parse_uri(URI)
try:
conn = MySQLdb.connect(host=params['host'], port = params['port'],
user=params['usr'], passwd=params['pwd'], db=params['db'])
except MySQLdb.OperationalError,err:
raise ConnectionError(err)
cursor = conn.cursor()
cursor.execute('SHOW TABLES;')
for r in cursor.fetchall():
if r[0] == params['coll']:
return True
return False
def collection_names(URI):
''' return list of collection names'''
params = parse_uri(URI)
conn = MySQLdb.connect(host=params['host'], port = params['port'],
user=params['usr'], passwd=params['pwd'], db=params['db'])
cursor = conn.cursor()
cursor.execute('SHOW TABLES;')
return cursor.fetchall()
def delete_collection(URI):
''' delete collection '''
if is_collection_exists(URI):
params = parse_uri(URI)
conn = MySQLdb.connect(host=params['host'], port = params['port'],
user=params['usr'], passwd=params['pwd'], db=params['db'])
cursor = conn.cursor()
cursor.execute('DROP TABLE %s;' % params['coll'])
conn.commit()
# -----------------------------------------------------------------
# Collection class
# -----------------------------------------------------------------
class Collection(object):
'''
kvlite2 collection
A collection is a group of documents stored in kvlite2,
and can be thought of as roughly the equivalent of a
table in a relational database.
'''
def __init__(self, db_uri):
'''
db_uri - URI to databases,
URI format: driver://username:passwd@host[:port]/database.collection
'''
params = parse_uri(db_uri)
self.__conn = MySQLdb.connect(host=params['host'], port = params['port'],
user=params['usr'], passwd=params['pwd'], db=params['db'])
self.__collection = params['coll']
self.__cursor = self.__conn.cursor()
self.__uuids = []
def get_uuid(self):
""" return id based on uuid """
if not self.__uuids:
self.__cursor.execute('SELECT %s;' % ','.join(['uuid()' for _ in range(100)]))
for uuid in self.__cursor.fetchone():
u = uuid.split('-')
u.reverse()
u = ("%040s" % ''.join(u)).replace(' ','0')
self.__uuids.append(u)
return self.__uuids.pop()
def pack(self, v):
''' pack value
Note: before pack the value it's better to encode it by base64
'''
return zlib.compress(json_encode(v))
def unpack(self, v):
''' unpack value
'''
return json_decode(zlib.decompress(v))
def __get_many(self):
''' return all docs '''
rowid = 0
while True:
SQL_SELECT_MANY = 'SELECT __rowid__, k,v FROM %s WHERE __rowid__ > %d LIMIT 1000 ;' % (self.__collection, rowid)
self.__cursor.execute(SQL_SELECT_MANY)
result = self.__cursor.fetchall()
if not result:
break
for r in result:
rowid = r[0]
k = binascii.b2a_hex(r[1])
try:
v = self.unpack(r[2])
except Exception, err:
raise ValueUnpackError('key %s, %s' % (k, err))
yield (k, v)
def get(self, k=None):
'''
return document by key from collection
return documents if key is not defined
'''
if k:
if len(k) > 40:
raise WronKeyValue()
SQL = 'SELECT k,v FROM %s WHERE k = ' % self.__collection
try:
self.__cursor.execute(SQL + "%s", binascii.a2b_hex(k))
except TypeError, err:
raise WronKeyValue(err)
result = self.__cursor.fetchone()
if result:
try:
v = self.unpack(result[1])
except Exception, err:
raise ValueUnpackError('key %s, %s' % (k, err))
return (binascii.b2a_hex(result[0]), v)
else:
return (None, None)
else:
return self.__get_many()
def put(self, k, v):
''' put document in collection '''
if len(k) > 40:
raise WronKeyValue()
SQL_INSERT = 'INSERT INTO %s (k,v) ' % self.__collection
SQL_INSERT += 'VALUES (%s,%s) ON DUPLICATE KEY UPDATE v=%s;;'
v = self.pack(v)
try:
self.__cursor.execute(SQL_INSERT, (binascii.a2b_hex(k), v, v))
except TypeError, err:
raise WronKeyValue(err)
def delete(self, k):
''' delete document by k '''
if len(k) > 40:
raise WronKeyValue()
SQL_DELETE = '''DELETE FROM %s WHERE k = ''' % self.__collection
try:
self.__cursor.execute(SQL_DELETE + "%s;", binascii.a2b_hex(k))
except TypeError, err:
raise WronKeyValue(err)
def keys(self):
''' return document keys in collection'''
rowid = 0
while True:
SQL_SELECT_MANY = 'SELECT __rowid__, k FROM %s WHERE __rowid__ > %d LIMIT 1000 ;' % (self.__collection, rowid)
self.__cursor.execute(SQL_SELECT_MANY)
result = self.__cursor.fetchall()
if not result:
break
for r in result:
rowid = r[0]
k = binascii.b2a_hex(r[1])
yield k
def count(self):
''' return amount of documents in collection'''
self.__cursor.execute('SELECT count(*) FROM %s;' % self.__collection)
return int(self.__cursor.fetchone()[0])
def commit(self):
self.__conn.commit()
def close(self):
''' close connection to database '''
self.__conn.close()
# -----------------------------------------------------------------
# Console class
# -----------------------------------------------------------------
class Console(cmd.Cmd):
def __init__(self):
cmd.Cmd.__init__(self)
self.prompt = "kvlite> "
self.ruler = '-'
self.__history_size = 20
self.__history = list()
self.__kvlite_colls = dict()
self.__current_coll_name = 'kvlite'
self.__current_coll = None
def emptyline(self):
return False
def do_help(self, arg):
''' help <command>\tshow <command> help'''
if arg:
try:
func = getattr(self, 'help_' + arg)
except AttributeError:
try:
doc=getattr(self, 'do_' + arg).__doc__
if doc:
self.stdout.write("%s\n"%str(doc))
return
except AttributeError:
pass
self.stdout.write("%s\n"%str(self.nohelp % (arg,)))
return
else:
names = [
'', 'do_help', 'do_version', 'do_licence', 'do_history', 'do_exit', '',
'do_create', 'do_use', 'do_show', 'do_remove', 'do_import', 'do_export', '',
'do_hash', 'do_keys', 'do_items', 'do_get', 'do_put', 'do_delete', 'do_count', ''
]
for name in names:
if not name:
print
else:
print getattr(self, name).__doc__
def do_history(self,line):
''' history\t\tshow commands history '''
for i, line in enumerate(self.__history):
print "0%d. %s" % (i+1, line)
def precmd(self, line):
if len(self.__history) == self.__history_size:
prev_line = self.__history.pop(0)
if line and line not in self.__history:
self.__history.append(line)
return line
def do_version(self, line):
''' version\t\tshow kvlite version'''
print 'version: %s' % __version__
def do_licence(self, line):
''' licence\t\tshow licence'''
print __license__
print
def do_exit(self, line):
''' exit\t\t\texit from console '''
return True
def do_import(self, filename):
''' import <filename>\timport collection configuration from JSON file'''
import os
if not filename:
print getattr(self, 'do_import').__doc__
return
filename = filename.rstrip().lstrip()
if os.path.isfile(filename):
for k, v in json_decode(open(filename).read()).items():
self.__kvlite_colls[k] = v
print 'Import completed'
else:
print 'Error! File %s does not exists' % filename
def do_export(self, filename):
''' export <filename>\texport collection configurations to JSON file'''
# TODO check if file exists. If yes, import about it
if not filename:
print getattr(self, 'do_import').__doc__
return
filename = filename.rstrip().lstrip()
json_file = open(filename, 'w')
json_file.write(json_encode(self.__kvlite_colls))
json_file.close()
print 'Export completed to file: %s' % filename
def do_show(self, line):
''' show collections\tlist of available collections (defined in settings.py)'''
if line == 'collections':
for coll in self.__kvlite_colls:
print ' %s' % coll
else:
print 'Unknown argument: %s' % line
def do_use(self, collection_name):
''' use <collection>\tuse the collection as the default (current) collection'''
if collection_name in self.__kvlite_colls:
self.prompt = '%s>' % collection_name
self.__current_coll_name = collection_name
self.__current_coll = Collection(self.__kvlite_colls[self.__current_coll_name])
return
else:
print 'Error! Unknown collection: %s' % collection_name
def do_create(self, line):
''' create <name> <uri>\tcreate new collection (if not exists)'''
try:
name, uri = [i for i in line.split(' ') if i <> '']
except ValueError:
print getattr(self, 'do_create').__doc__
return
if name in self.__kvlite_colls:
print 'Warning! Collection name already defined: %s, %s' % (name, self.__kvlite_colls[name])
print 'If needed please change collection name'
return
try:
if is_collection_exists(uri):
self.__kvlite_colls[name] = uri
print 'Connection exists, the reference added to collection list'
return
else:
create_collection(uri)
self.__kvlite_colls[name] = uri
print 'Collection created and added to collection list'
return
except WrongURIException:
print 'Error! Incorrect URI'
return
except ConnectionError, err:
print 'Connection Error! Please check URI, %s' % str(err)
return
def do_remove(self, name):
''' remove <collection>\tremove collection'''
if name not in self.__kvlite_colls:
print 'Error! Collection name does not exist: %s' % name
return
try:
if is_collection_exists(self.__kvlite_colls[name]):
delete_collection(self.__kvlite_colls[name])
del self.__kvlite_colls[name]
print 'Collection %s deleted' % name
return
else:
print 'Error! Collection does not exist, %s' % self.__kvlite_colls[name]
except WrongURIException:
print 'Error! Incorrect URI'
return
except ConnectionError, err:
print 'Connection Error! Please check URI, %s' % str(err)
return
def do_hash(self, line):
''' hash [string]\tgenerate sha1 hash, random if string is not defined'''
import hashlib
import datetime
if not line:
str_now = str(datetime.datetime.now())
print 'Random sha1 hash:', hashlib.sha1(str_now).hexdigest()
else:
line = line.rstrip().lstrip()
print 'sha1 hash:', hashlib.sha1(line).hexdigest()
def do_keys(self, line):
''' keys\t\t\tlist of keys '''
if not self.__current_coll_name in self.__kvlite_colls:
print 'Error! Unknown collection: %s' % self.__current_coll_name
return
for k,v in self.__current_coll.get():
print k
def do_items(self, line):
''' items\t\tlist of collection's items '''
if not self.__current_coll_name in self.__kvlite_colls:
print 'Error! Unknown collection: %s' % self.__current_coll_name
return
for k,v in self.__current_coll.get():
print k
pprint.pprint(v)
print
def do_count(self, args):
''' count\t\tshow the amount of entries in collection '''
if self.__current_coll:
print self.__current_coll.count()
def do_get(self, key):
''' get <key>\t\tshow collection entry by key'''
if not key:
print getattr(self, 'do_get').__doc__
return
for key in [k for k in key.split(' ') if k <> '']:
if self.__current_coll:
k, v = self.__current_coll.get(key)
print k
pprint.pprint(v)
print
else:
print 'Error! The collection is not selected, please use collection'
return
def do_put(self, line):
''' put <key> <value>\tstore entry to collection'''
try:
k,v = [i for i in line.split(' ',1) if i <> '']
except ValueError:
print getattr(self, 'do_put').__doc__
return
try:
v = json_decode(v)
except ValueError, err:
print 'Value decoding error!', err
return
if self.__current_coll:
try:
self.__current_coll.put(k, v)
self.__current_coll.commit()
print 'Done'
return
except WronKeyValue, err:
print 'Error! Incorrect key/value,', err
return
else:
print 'Error! The collection is not selected, please use collection'
return
def do_delete(self, key):
''' delete <key>\t\tdelete entry by key '''
key = key.rstrip().lstrip()
if self.__current_coll.get(key) <> (None, None):
self.__current_coll.delete(key)
self.__current_coll.commit()
print 'Done'
return
else:
print 'Error! The key %s does not exist' % key
return
# ----------------------------------
# main
# ----------------------------------
if __name__ == '__main__':
console = Console()
console.cmdloop()
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