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sqlitedb.py
271 lines | 8.7 KiB | text/x-python | PythonLexer
"""A TaskRecord backend using sqlite3"""
#-----------------------------------------------------------------------------
# Copyright (C) 2011 The IPython Development Team
#
# Distributed under the terms of the BSD License. The full license is in
# the file COPYING, distributed as part of this software.
#-----------------------------------------------------------------------------
import json
import os
import cPickle as pickle
from datetime import datetime
import sqlite3
from IPython.utils.traitlets import CUnicode, CStr, Instance, List
from .dictdb import BaseDB
from .util import ISO8601
#-----------------------------------------------------------------------------
# SQLite operators, adapters, and converters
#-----------------------------------------------------------------------------
operators = {
'$lt' : lambda a,b: "%s < ?",
'$gt' : ">",
# null is handled weird with ==,!=
'$eq' : "IS",
'$ne' : "IS NOT",
'$lte': "<=",
'$gte': ">=",
'$in' : ('IS', ' OR '),
'$nin': ('IS NOT', ' AND '),
# '$all': None,
# '$mod': None,
# '$exists' : None
}
def _adapt_datetime(dt):
return dt.strftime(ISO8601)
def _convert_datetime(ds):
if ds is None:
return ds
else:
return datetime.strptime(ds, ISO8601)
def _adapt_dict(d):
return json.dumps(d)
def _convert_dict(ds):
if ds is None:
return ds
else:
return json.loads(ds)
def _adapt_bufs(bufs):
# this is *horrible*
# copy buffers into single list and pickle it:
if bufs and isinstance(bufs[0], (bytes, buffer)):
return sqlite3.Binary(pickle.dumps(map(bytes, bufs),-1))
elif bufs:
return bufs
else:
return None
def _convert_bufs(bs):
if bs is None:
return []
else:
return pickle.loads(bytes(bs))
#-----------------------------------------------------------------------------
# SQLiteDB class
#-----------------------------------------------------------------------------
class SQLiteDB(BaseDB):
"""SQLite3 TaskRecord backend."""
filename = CUnicode('tasks.db', config=True)
location = CUnicode('', config=True)
table = CUnicode("", config=True)
_db = Instance('sqlite3.Connection')
_keys = List(['msg_id' ,
'header' ,
'content',
'buffers',
'submitted',
'client_uuid' ,
'engine_uuid' ,
'started',
'completed',
'resubmitted',
'result_header' ,
'result_content' ,
'result_buffers' ,
'queue' ,
'pyin' ,
'pyout',
'pyerr',
'stdout',
'stderr',
])
def __init__(self, **kwargs):
super(SQLiteDB, self).__init__(**kwargs)
if not self.table:
# use session, and prefix _, since starting with # is illegal
self.table = '_'+self.session.replace('-','_')
if not self.location:
if hasattr(self.config.Global, 'cluster_dir'):
self.location = self.config.Global.cluster_dir
else:
self.location = '.'
self._init_db()
def _defaults(self):
"""create an empty record"""
d = {}
for key in self._keys:
d[key] = None
return d
def _init_db(self):
"""Connect to the database and get new session number."""
# register adapters
sqlite3.register_adapter(datetime, _adapt_datetime)
sqlite3.register_converter('datetime', _convert_datetime)
sqlite3.register_adapter(dict, _adapt_dict)
sqlite3.register_converter('dict', _convert_dict)
sqlite3.register_adapter(list, _adapt_bufs)
sqlite3.register_converter('bufs', _convert_bufs)
# connect to the db
dbfile = os.path.join(self.location, self.filename)
self._db = sqlite3.connect(dbfile, detect_types=sqlite3.PARSE_DECLTYPES)
self._db.execute("""CREATE TABLE IF NOT EXISTS %s
(msg_id text PRIMARY KEY,
header dict text,
content dict text,
buffers bufs blob,
submitted datetime text,
client_uuid text,
engine_uuid text,
started datetime text,
completed datetime text,
resubmitted datetime text,
result_header dict text,
result_content dict text,
result_buffers bufs blob,
queue text,
pyin text,
pyout text,
pyerr text,
stdout text,
stderr text)
"""%self.table)
# self._db.execute("""CREATE TABLE IF NOT EXISTS %s_buffers
# (msg_id text, result integer, buffer blob)
# """%self.table)
self._db.commit()
def _dict_to_list(self, d):
"""turn a mongodb-style record dict into a list."""
return [ d[key] for key in self._keys ]
def _list_to_dict(self, line):
"""Inverse of dict_to_list"""
d = self._defaults()
for key,value in zip(self._keys, line):
d[key] = value
return d
def _render_expression(self, check):
"""Turn a mongodb-style search dict into an SQL query."""
expressions = []
args = []
skeys = set(check.keys())
skeys.difference_update(set(self._keys))
skeys.difference_update(set(['buffers', 'result_buffers']))
if skeys:
raise KeyError("Illegal testing key(s): %s"%skeys)
for name,sub_check in check.iteritems():
if isinstance(sub_check, dict):
for test,value in sub_check.iteritems():
try:
op = operators[test]
except KeyError:
raise KeyError("Unsupported operator: %r"%test)
if isinstance(op, tuple):
op, join = op
expr = "%s %s ?"%(name, op)
if isinstance(value, (tuple,list)):
expr = '( %s )'%( join.join([expr]*len(value)) )
args.extend(value)
else:
args.append(value)
expressions.append(expr)
else:
# it's an equality check
expressions.append("%s IS ?"%name)
args.append(sub_check)
expr = " AND ".join(expressions)
return expr, args
def add_record(self, msg_id, rec):
"""Add a new Task Record, by msg_id."""
d = self._defaults()
d.update(rec)
d['msg_id'] = msg_id
line = self._dict_to_list(d)
tups = '(%s)'%(','.join(['?']*len(line)))
self._db.execute("INSERT INTO %s VALUES %s"%(self.table, tups), line)
self._db.commit()
def get_record(self, msg_id):
"""Get a specific Task Record, by msg_id."""
cursor = self._db.execute("""SELECT * FROM %s WHERE msg_id==?"""%self.table, (msg_id,))
line = cursor.fetchone()
if line is None:
raise KeyError("No such msg: %r"%msg_id)
return self._list_to_dict(line)
def update_record(self, msg_id, rec):
"""Update the data in an existing record."""
query = "UPDATE %s SET "%self.table
sets = []
keys = sorted(rec.keys())
values = []
for key in keys:
sets.append('%s = ?'%key)
values.append(rec[key])
query += ', '.join(sets)
query += ' WHERE msg_id == %r'%msg_id
self._db.execute(query, values)
self._db.commit()
def drop_record(self, msg_id):
"""Remove a record from the DB."""
self._db.execute("""DELETE FROM %s WHERE mgs_id==?"""%self.table, (msg_id,))
self._db.commit()
def drop_matching_records(self, check):
"""Remove a record from the DB."""
expr,args = self._render_expression(check)
query = "DELETE FROM %s WHERE %s"%(self.table, expr)
self._db.execute(query,args)
self._db.commit()
def find_records(self, check, id_only=False):
"""Find records matching a query dict."""
req = 'msg_id' if id_only else '*'
expr,args = self._render_expression(check)
query = """SELECT %s FROM %s WHERE %s"""%(req, self.table, expr)
cursor = self._db.execute(query, args)
matches = cursor.fetchall()
if id_only:
return [ m[0] for m in matches ]
else:
records = {}
for line in matches:
rec = self._list_to_dict(line)
records[rec['msg_id']] = rec
return records
__all__ = ['SQLiteDB']