.BANCHO. New MySQL helper
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Nyo
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commit
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@ -1,117 +1,196 @@
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import queue
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import MySQLdb
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import threading
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import glob
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from helpers import logHelper as log
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import threading
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class mysqlWorker:
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class worker():
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"""
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Instance of a pettirosso meme
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A single MySQL worker
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"""
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def __init__(self, wid, host, username, password, database):
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def __init__(self, connection, temporary=False):
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"""
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Create a pettirosso meme (mysql worker)
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Initialize a MySQL worker
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wid -- worker id
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host -- hostname
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username -- MySQL username
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password -- MySQL password
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database -- MySQL database name
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:param connection: database connection object
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:param temporary: if True, this worker will be flagged as temporary
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"""
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self.wid = wid
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self.connection = MySQLdb.connect(host, username, password, database)
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self.connection.autocommit(True)
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self.ready = True
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self.lock = threading.Lock()
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self.connection = connection
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self.temporary = temporary
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log.debug("Created MySQL worker. Temporary: {}".format(self.temporary))
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class db:
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def ping(self):
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"""
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Ping MySQL server using this worker.
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:return: True if connected, False if error occured.
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"""
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try:
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self.connection.cursor(MySQLdb.cursors.DictCursor).execute("SELECT 1+1")
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return True
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except:
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return False
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def __del__(self):
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"""
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Close connection to the server
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:return:
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"""
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self.connection.close()
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log.debug("Destroyed MySQL worker.")
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class connectionsPool():
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"""
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A MySQL db connection with multiple workers
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A MySQL workers pool
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"""
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def __init__(self, host, username, password, database, initialSize=16):
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"""
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Initialize a MySQL connections pool
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def __init__(self, host, username, password, database, workers):
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:param host: MySQL host
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:param username: MySQL username
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:param password: MySQL password
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:param database: MySQL database name
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:param initialSize: initial pool size
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"""
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Create MySQL workers aka pettirossi meme
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self.config = (host, username, password, database)
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self.maxSize = initialSize
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self.pool = queue.Queue(0)
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self.consecutiveEmptyPool = 0
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self.fillPool()
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host -- hostname
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username -- MySQL username
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password -- MySQL password
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database -- MySQL database name
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workers -- Number of workers to spawn
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def newWorker(self, temporary=False):
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"""
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self.workers = []
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self.lastWorker = 0
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self.workersNumber = workers
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self.locked = 0
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for i in range(0,self.workersNumber):
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print(".", end="")
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self.workers.append(mysqlWorker(i, host, username, password, database))
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Create a new worker.
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def checkPoolSaturation(self):
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:param temporary: if True, flag the worker as temporary
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:return: instance of worker class
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"""
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Check the number of busy connections in connections pool.
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If the pool is 100% busy, log a message to sentry
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db = MySQLdb.connect(*self.config)
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db.autocommit(True)
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conn = worker(db, temporary)
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return conn
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def expandPool(self, newWorkers=5):
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"""
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if self.locked >= (self.workersNumber-1):
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msg = "MySQL connections pool is saturated!".format(self.locked, self.workersNumber)
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log.warning(msg)
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glob.application.sentry_client.captureMessage(msg, level="warning", extra={
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"workersBusy": self.locked,
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"workersTotal": self.workersNumber
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})
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Add some new workers to the pool
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:param newWorkers: number of new workers
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:return:
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"""
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self.maxSize += newWorkers
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self.fillPool()
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def fillPool(self):
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"""
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Fill the queue with workers until its maxSize
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:return:
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"""
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size = self.pool.qsize()
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if self.maxSize > 0 and size >= self.maxSize:
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return
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newConnections = self.maxSize-size
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for _ in range(0, newConnections):
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self.pool.put_nowait(self.newWorker())
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def getWorker(self):
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"""
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Return a worker object (round-robin way)
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Get a MySQL connection worker from the pool.
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If the pool is empty, a new temporary worker is created.
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return -- worker object
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:return: instance of worker class
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"""
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if self.lastWorker >= self.workersNumber-1:
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self.lastWorker = 0
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else:
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self.lastWorker += 1
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# Saturation check
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threading.Thread(target=self.checkPoolSaturation).start()
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self.locked += 1
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return self.workers[self.lastWorker]
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if self.pool.empty():
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# The pool is empty. Spawn a new temporary worker
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log.warning("Using temporary worker")
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worker = self.newWorker(True)
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# Increment saturation
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self.consecutiveEmptyPool += 1
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# If the pool is usually empty, expand it
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if self.consecutiveEmptyPool >= 5:
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log.warning("MySQL connections pool is saturated. Filling connections pool.")
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self.expandPool()
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else:
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# The pool is not empty. Get worker from the pool
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# and reset saturation counter
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worker = self.pool.get()
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self.consecutiveEmptyPool = 0
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# Return the connection
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return worker
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def putWorker(self, worker):
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"""
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Put the worker back in the pool.
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If the worker is temporary, close the connection
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and destroy the object
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:param worker: worker object
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:return:
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"""
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if worker.temporary:
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del worker
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else:
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self.pool.put_nowait(worker)
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class db:
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"""
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A MySQL helper with multiple workers
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"""
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def __init__(self, host, username, password, database, initialSize):
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"""
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Initialize a new MySQL database helper with multiple workers.
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This class is thread safe.
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:param host: MySQL host
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:param username: MySQL username
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:param password: MySQL password
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:param database: MySQL database name
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:param initialSize: initial pool size
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"""
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self.pool = connectionsPool(host, username, password, database, initialSize)
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def execute(self, query, params = ()):
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"""
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Executes a query
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query -- Query to execute. You can bind parameters with %s
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params -- Parameters list. First element replaces first %s and so on. Optional.
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:param query: query to execute. You can bind parameters with %s
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:param params: parameters list. First element replaces first %s and so on
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"""
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log.debug(query)
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# Get a worker and acquire its lock
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worker = self.getWorker()
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worker.lock.acquire()
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cursor = None
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worker = self.pool.getWorker()
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try:
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# Create cursor, execute query and commit
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cursor = worker.connection.cursor(MySQLdb.cursors.DictCursor)
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cursor.execute(query, params)
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return cursor.lastrowid
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except MySQLdb.OperationalError:
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del worker
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worker = None
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self.execute(query, params)
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finally:
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# Close the cursor and release worker's lock
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if cursor:
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if cursor is not None:
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cursor.close()
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worker.lock.release()
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self.locked -= 1
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if worker is not None:
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self.pool.putWorker(worker)
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def fetch(self, query, params = (), all = False):
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"""
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Fetch a single value from db that matches given query
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query -- Query to execute. You can bind parameters with %s
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params -- Parameters list. First element replaces first %s and so on. Optional.
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all -- Fetch one or all values. Used internally. Use fetchAll if you want to fetch all values.
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:param query: query to execute. You can bind parameters with %s
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:param params: parameters list. First element replaces first %s and so on
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:param all: fetch one or all values. Used internally. Use fetchAll if you want to fetch all values
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"""
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log.debug(query)
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# Get a worker and acquire its lock
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worker = self.getWorker()
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worker.lock.acquire()
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cursor = None
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worker = self.pool.getWorker()
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try:
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# Create cursor, execute the query and fetch one/all result(s)
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@ -121,19 +200,23 @@ class db:
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return cursor.fetchall()
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else:
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return cursor.fetchone()
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except MySQLdb.OperationalError:
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del worker
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worker = None
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self.fetch(query, params, all)
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finally:
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# Close the cursor and release worker's lock
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if cursor:
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if cursor is not None:
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cursor.close()
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worker.lock.release()
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self.locked -= 1
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if worker is not None:
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self.pool.putWorker(worker)
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def fetchAll(self, query, params = ()):
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"""
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Fetch all values from db that matche given query.
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Calls self.fetch with all = True.
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query -- Query to execute. You can bind parameters with %s
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params -- Parameters list. First element replaces first %s and so on. Optional.
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:param query: query to execute. You can bind parameters with %s
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:param params: parameters list. First element replaces first %s and so on
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"""
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return self.fetch(query, params, True)
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