Claim resource only temporarily

This commit is contained in:
richard-dds
2019-09-17 11:03:33 -04:00
parent 945debe6ee
commit abeadee3f3
4 changed files with 20 additions and 11 deletions

View File

@@ -29,7 +29,7 @@ class Environment(
root_user_info = Column(JSONB)
baseline_info = Column(JSONB)
claimed_at = Column(TIMESTAMP(timezone=True))
claimed_until = Column(TIMESTAMP(timezone=True))
job_failures = relationship("EnvironmentJobFailure")

View File

@@ -1,4 +1,4 @@
from sqlalchemy import func, sql
from sqlalchemy import func, sql, Interval, and_, or_
from contextlib import contextmanager
from atst.database import db
@@ -6,13 +6,22 @@ from atst.domain.exceptions import ClaimFailedException
@contextmanager
def claim_for_update(resource):
def claim_for_update(resource, minutes=30):
Model = resource.__class__
claim_until = func.now() + func.cast(
sql.functions.concat(minutes, " MINUTES"), Interval
)
rows_updated = (
db.session.query(Model)
.filter_by(id=resource.id, claimed_at=None)
.update({"claimed_at": func.now()}, synchronize_session=False)
.filter(
and_(
Model.id == resource.id,
or_(Model.claimed_until == None, Model.claimed_until < func.now()),
)
)
.update({"claimed_until": claim_until}, synchronize_session=False)
)
if rows_updated < 1:
raise ClaimFailedException(resource)
@@ -23,5 +32,5 @@ def claim_for_update(resource):
yield claimed
finally:
db.session.query(Model).filter(Model.id == resource.id).filter(
Model.claimed_at != None
).update({"claimed_at": sql.null()}, synchronize_session=False)
Model.claimed_until != None
).update({"claimed_until": sql.null()}, synchronize_session=False)