def wait_for_first(condition):
selector_factory = lambda: first(condition)
items, lock = wait_for(selector_factory)
assert len(items) == 1
return items[0], lock
def wait_for_first(condition, reason):
selector_factory = lambda: first(condition)
items, lock = wait_for(selector_factory, reason)
assert len(items) == 1
return items[0], lock
def lock_items(filename, lock, term_generator=None, lock_reason=None):
"""
>>> import os
>>> if os.path.exists('test_db'): os.unlink('test_db')
>>> set_database('test_db', '[dict(HOST=\"1\"), dict(HOST=\"2\"), dict(HOST=\"3\")]')
>>> from selectors import first
>>> lock_items('test_db', 'a', first(lambda x: x['HOST'] == '1'))
[{'HOST': '1'}]
>>> lock_items('test_db', 'b', first(lambda x: x['HOST'] == '2'))
[{'HOST': '2'}]
>>> lock_items('test_db', '', first(lambda x: x['HOST'] == '3'))
Traceback (most recent call last):
...
ValueError: Invalid lock value: ''
>>> set_database('test_db', '[]')
>>> lock_items('test_db', 'c')
[]
>>> set_database('test_db', '[dict(HOST=\"1\"), dict(HOST=\"2\"), dict(HOST=\"3\")]')
>>> seen_items = []
>>> lock_items('test_db', 'a', lambda x: lambda: seen_items.append(x))
[]
>>> seen_items.sort()
>>> seen_items
[{'HOST': '1'}, {'HOST': '2'}, {'HOST': '3'}]
"""
if lock == "":
raise ValueError("Invalid lock value: %s" % repr(lock))
import sqlite3
conn = sqlite3.connect(filename, isolation_level='EXCLUSIVE')
c = conn.cursor()
term_generator = term_generator or first()
terms_ids_items = []
for id, data in c.execute('SELECT id, data FROM stuff WHERE lock = :empty_lock ORDER by random()', dict(empty_lock="")).fetchall():
item = eval(data)
terms_ids_items.append((term_generator(item), id, item))
results = []
for term, id, item in terms_ids_items:
if term():
c.execute('UPDATE stuff SET lock = :lock, lock_date = datetime(\'now\') WHERE id = :id', dict(lock=lock, id=id))
assert c.rowcount == 1
results.append(item)
if lock_reason:
c.execute('UPDATE stuff SET lock_reason = :lock_reason WHERE id = :id', dict(lock_reason=lock_reason, id=id))
assert c.rowcount == 1
conn.commit()
conn.close()
return results
def lock_items(filename, lock, term_generator=None):
"""
>>> set_database('test_db', '[1, 2, 3]')
>>> lock_items('test_db', 'a')
[1]
>>> lock_items('test_db', 'b')
[2]
>>> lock_items('test_db', '')
Traceback (most recent call last):
...
ValueError: Invalid lock value: ''
>>> set_database('test_db', '[]')
>>> lock_items('test_db', 'c')
[]
>>> set_database('test_db', '[1, 2, 3]')
>>> seen_items = []
>>> lock_items('test_db', 'a', lambda x: lambda: seen_items.append(x))
[]
>>> seen_items
[1, 2, 3]
"""
if lock == "":
raise ValueError("Invalid lock value: %s" % repr(lock))
import sqlite3
conn = sqlite3.connect(filename)
c = conn.cursor()
term_generator = term_generator or first()
stmt = 'SELECT id, data FROM stuff WHERE lock = :empty_lock ORDER by id'
terms_ids_items = []
for id, data in c.execute(stmt, dict(empty_lock="")).fetchall():
item = eval(data)
terms_ids_items.append((term_generator(item), id, item))
results = []
for term, id, item in terms_ids_items:
if term():
c.execute(
'UPDATE stuff SET lock = :lock WHERE id = :id',
dict(lock=lock, id=id)
)
assert c.rowcount == 1
results.append(item)
conn.commit()
conn.close()
return results
def lock_items(filename, lock, term_generator=None, lock_reason=None):
"""
>>> import os
>>> if os.path.exists('test_db'): os.unlink('test_db')
>>> set_database('test_db', '[dict(HOST=\"1\"), dict(HOST=\"2\"), dict(HOST=\"3\")]')
>>> from selectors import first
>>> lock_items('test_db', 'a', first(lambda x: x['HOST'] == '1'))
[{'HOST': '1'}]
>>> lock_items('test_db', 'b', first(lambda x: x['HOST'] == '2'))
[{'HOST': '2'}]
>>> lock_items('test_db', '', first(lambda x: x['HOST'] == '3'))
Traceback (most recent call last):
...
ValueError: Invalid lock value: ''
>>> set_database('test_db', '[]')
>>> lock_items('test_db', 'c')
[]
>>> set_database('test_db', '[dict(HOST=\"1\"), dict(HOST=\"2\"), dict(HOST=\"3\")]')
>>> seen_items = []
>>> lock_items('test_db', 'a', lambda x: lambda: seen_items.append(x))
[]
>>> seen_items.sort()
>>> seen_items
[{'HOST': '1'}, {'HOST': '2'}, {'HOST': '3'}]
"""
if lock == "":
raise ValueError("Invalid lock value: %s" % repr(lock))
import sqlite3
conn = sqlite3.connect(filename, isolation_level='EXCLUSIVE')
c = conn.cursor()
term_generator = term_generator or first()
terms_ids_items = []
for id, data in c.execute(
'SELECT id, data FROM stuff WHERE lock = :empty_lock ORDER by random()',
dict(empty_lock="")).fetchall():
item = eval(data)
terms_ids_items.append((term_generator(item), id, item))
results = []
for term, id, item in terms_ids_items:
if term():
c.execute(
'UPDATE stuff SET lock = :lock, lock_date = datetime(\'now\') WHERE id = :id',
dict(lock=lock, id=id))
assert c.rowcount == 1
results.append(item)
lock_reason = lock_reason or ''
c.execute(
'UPDATE stuff SET lock_reason = :lock_reason WHERE id = :id',
dict(lock_reason=lock_reason, id=id))
assert c.rowcount == 1
conn.commit()
conn.close()
return results