CCF_100/relational
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Removed unmaintained parallel module

Browse Source 
The module is unmaintained and in any case, does not limit the
amount of parallel jobs.
This commit is contained in:
Salvo 'LtWorf' Tomaselli 2015-06-02 14:58:20 +02:00
parent 62c51ab150
commit f2bde1b6bd
1 changed files with 0 additions and 117 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

117
relational/parallel.py
View File

@ -1,117 +0,0 @@
# -*- coding: utf-8 -*-
# Relational
# Copyright (C) 2009 Salvo "LtWorf" Tomaselli
#
# Relational is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
# author Salvo "LtWorf" Tomaselli <tiposchi@tiscali.it>
#
# This module offers capability of executing relational queries in parallel.
import optimizer
import multiprocessing
import parser
def execute(tree, rels):
'''This funcion executes a query in parallel.
Tree is the tree describing the query (usually obtained with
parser.tree(querystring)
rels is a dictionary containing the relations associated with the names'''
q = multiprocessing.Queue()
p = multiprocessing.Process(target=__p_exec__, args=(tree, rels, q,))
p.start()
result = q.get()
p.join()
return result
def __p_exec__(tree, rels, q):
'''q is the queue used for communication'''
if tree.kind == parser.RELATION:
q.put(rels[tree.name])
elif tree.kind == parser.UNARY:
# Obtain the relation
temp_q = multiprocessing.Queue()
__p_exec__(tree.child, rels, temp_q)
rel = temp_q.get()
# Execute the query
result = __p_exec_unary__(tree, rel)
q.put(result)
elif tree.kind == parser.BINARY:
left_q = multiprocessing.Queue()
left_p = multiprocessing.Process(
target=__p_exec__, args=(tree.left, rels, left_q,))
right_q = multiprocessing.Queue()
right_p = multiprocessing.Process(
target=__p_exec__, args=(tree.right, rels, right_q,))
# Spawn the children
left_p.start()
right_p.start()
# Get the left and right relations
left = left_q.get()
right = right_q.get()
# Wait for the children to terminate
left_p.join()
right_p.join()
result = __p_exec_binary__(tree, left, right)
q.put(result)
return
def __p_exec_binary__(tree, left, right):
if tree.name == '*':
return left.product(right)
elif tree.name == '-':
return left.difference(right)
elif tree.name == 'ᑌ':
return left.union(right)
elif tree.name == 'ᑎ':
return left.intersection(right)
elif tree.name == '÷':
return left.division(right)
elif tree.name == 'ᐅᐊ':
return left.join(right)
elif tree.name == 'ᐅLEFTᐊ':
return left.outer_left(right)
elif tree.name == 'ᐅRIGHTᐊ':
return left.outer_right(right)
else: # tree.name=='ᐅFULLᐊ':
return left.outer(right)
def __p_exec_unary__(tree, rel):
if tree.name == 'π': # Projection
tree.prop = tree.prop.replace(' ', '').split(',')
result = rel.projection(tree.prop)
elif tree.name == "ρ": # Rename
# tree.prop='{\"%s\"}' %
# tree.prop.replace(',','\",\"').replace('➡','\":\"').replace(' ','')
d = {}
tree.prop = tree.prop.replace(' ', '')
for i in tree.prop.split(','):
rename_ = i.split('➡')
d[rename_[0]] = rename_[1]
result = rel.rename(d)
else: # Selection
result = rel.selection(tree.prop)
return result