Dmitri Bogomolov
341651973a
- exported from network package all objects used outside; - made all threads available in threads module. Wrote some module docstrings.
122 lines
3.5 KiB
Python
122 lines
3.5 KiB
Python
"""
|
|
SQL-related functions defined here are really pass the queries (or other SQL
|
|
commands) to :class:`.threads.sqlThread` through `sqlSubmitQueue` queue and check
|
|
or return the result got from `sqlReturnQueue`.
|
|
|
|
This is done that way because :mod:`sqlite3` is so thread-unsafe that they
|
|
won't even let you call it from different threads using your own locks.
|
|
SQLite objects can only be used from one thread.
|
|
|
|
.. note:: This actually only applies for certain deployments, and/or
|
|
really old version of sqlite. I haven't actually seen it anywhere.
|
|
Current versions do have support for threading and multiprocessing.
|
|
I don't see an urgent reason to refactor this, but it should be noted
|
|
in the comment that the problem is mostly not valid. Sadly, last time
|
|
I checked, there is no reliable way to check whether the library is
|
|
or isn't thread-safe.
|
|
"""
|
|
|
|
import threading
|
|
import Queue
|
|
|
|
sqlSubmitQueue = Queue.Queue()
|
|
"""the queue for SQL"""
|
|
sqlReturnQueue = Queue.Queue()
|
|
"""the queue for results"""
|
|
sqlLock = threading.Lock()
|
|
|
|
|
|
def sqlQuery(sqlStatement, *args):
|
|
"""
|
|
Query sqlite and return results
|
|
|
|
:param str sqlStatement: SQL statement string
|
|
:param list args: SQL query parameters
|
|
:rtype: list
|
|
"""
|
|
sqlLock.acquire()
|
|
sqlSubmitQueue.put(sqlStatement)
|
|
|
|
if args == ():
|
|
sqlSubmitQueue.put('')
|
|
elif isinstance(args[0], (list, tuple)):
|
|
sqlSubmitQueue.put(args[0])
|
|
else:
|
|
sqlSubmitQueue.put(args)
|
|
queryreturn, _ = sqlReturnQueue.get()
|
|
sqlLock.release()
|
|
|
|
return queryreturn
|
|
|
|
|
|
def sqlExecuteChunked(sqlStatement, idCount, *args):
|
|
# SQLITE_MAX_VARIABLE_NUMBER,
|
|
# unfortunately getting/setting isn't exposed to python
|
|
sqlExecuteChunked.chunkSize = 999
|
|
|
|
if idCount == 0 or idCount > len(args):
|
|
return 0
|
|
|
|
totalRowCount = 0
|
|
with sqlLock:
|
|
for i in range(
|
|
len(args) - idCount, len(args),
|
|
sqlExecuteChunked.chunkSize - (len(args) - idCount)
|
|
):
|
|
chunk_slice = args[
|
|
i:i + sqlExecuteChunked.chunkSize - (len(args) - idCount)
|
|
]
|
|
sqlSubmitQueue.put(
|
|
sqlStatement.format(','.join('?' * len(chunk_slice)))
|
|
)
|
|
# first static args, and then iterative chunk
|
|
sqlSubmitQueue.put(
|
|
args[0:len(args) - idCount] + chunk_slice
|
|
)
|
|
retVal = sqlReturnQueue.get()
|
|
totalRowCount += retVal[1]
|
|
sqlSubmitQueue.put('commit')
|
|
return totalRowCount
|
|
|
|
|
|
def sqlExecute(sqlStatement, *args):
|
|
sqlLock.acquire()
|
|
sqlSubmitQueue.put(sqlStatement)
|
|
|
|
if args == ():
|
|
sqlSubmitQueue.put('')
|
|
else:
|
|
sqlSubmitQueue.put(args)
|
|
_, rowcount = sqlReturnQueue.get()
|
|
sqlSubmitQueue.put('commit')
|
|
sqlLock.release()
|
|
return rowcount
|
|
|
|
def sqlStoredProcedure(procName):
|
|
sqlLock.acquire()
|
|
sqlSubmitQueue.put(procName)
|
|
sqlLock.release()
|
|
|
|
|
|
class SqlBulkExecute:
|
|
"""This is used when you have to execute the same statement in a cycle."""
|
|
|
|
def __enter__(self):
|
|
sqlLock.acquire()
|
|
return self
|
|
|
|
def __exit__(self, exc_type, value, traceback):
|
|
sqlSubmitQueue.put('commit')
|
|
sqlLock.release()
|
|
|
|
@staticmethod
|
|
def execute(sqlStatement, *args):
|
|
"""Used for statements that do not return results."""
|
|
sqlSubmitQueue.put(sqlStatement)
|
|
|
|
if args == ():
|
|
sqlSubmitQueue.put('')
|
|
else:
|
|
sqlSubmitQueue.put(args)
|
|
sqlReturnQueue.get()
|