def delete(self, key, rev=None):
tx = self.db.transaction()
try:
row = self.get_row(key, for_update=True)
if row:
if rev is not None and str(row.id) != str(rev):
raise common.Conflict(key=key, message="Document update conflict")
self.delete_row(row.id)
except:
tx.rollback()
raise
else:
tx.commit()
self.fire_event("store.delete", {"key": key})
def put(self, key, doc):
if doc.get("_delete") is True:
return self.delete(key, doc.get("_rev"))
# conflict check is enabled by default. It can be disabled by passing _rev=None in the document.
if "_rev" in doc and doc["_rev"] is None:
enable_conflict_check = False
else:
enable_conflict_check = True
doc.pop("_key", None)
rev = doc.pop("_rev", None)
json_data = simplejson.dumps(doc)
tx = self.db.transaction()
try:
row = self.get_row(key, for_update=True)
if row:
if enable_conflict_check and str(row.id) != str(rev):
raise common.Conflict(key=key,
message="Document update conflict")
self.delete_index(row.id)
# store query results are always order by id column.
# It is important to update the id so that the newly modified
# records show up first in the results.
self.db.query(
"UPDATE store SET json=$json_data, id=nextval('store_id_seq') WHERE key=$key",
vars=locals(),
)
id = self.get_row(key=key).id
else:
id = self.db.insert("store", key=key, json=json_data)
self.add_index(id, key, doc)
doc['_key'] = key
doc['_rev'] = str(id)
except:
tx.rollback()
raise
else:
tx.commit()
self.fire_event("store.put", {"key": key, "data": doc})
return doc
def _load_records(self, keys):
"""Returns a dictionary of records for the given keys.
The records are queried FOR UPDATE to lock those rows from concurrent updates.
Each record is a storage object with (id, key, type, revision, last_modified, data) keys.
"""
try:
rows = self.db.query(
"SELECT thing.*, data.data FROM thing, data" +
" WHERE thing.key in $keys" +
" AND data.thing_id=thing.id AND data.revision = thing.latest_revision"
+ " FOR UPDATE NOWAIT",
vars=locals())
except:
raise common.Conflict(keys=keys, reason="Edit conflict detected.")
records = dict((r.key, r) for r in rows)
for r in records.values():
r.revision = r.latest_revision
json = r.data and self.process_json(r.key, r.data)
r.data = simplejson.loads(json)
return records
