def handle_request(layer_id, redis_conn):
'''handler for any item pulled from worker job queue
This handler is called every time the worker is able to pop a message
from the job queue filled by the registry. The worker blocks until a
message is available. This handler will then attempt to aquire a lock
for the provided layer_id and if successful, process a diff for the
layer.
If the lock for this layer_id has already been aquired for this layer
the worker will immediately timeout to block for another request.
'''
try:
# this with-context will attempt to establish a 5 minute lock
# on the key for this layer, immediately passing on LockTimeout
# if one isn't availble
with rlock.Lock(redis_conn,
"diff-worker-lock",
layer_id,
expires=60 * 5):
# first check if a cached result is already available. The registry
# already does this, but hey.
diff_data = layers.get_image_diff_cache(layer_id)
if not diff_data:
log.info("Processing diff for %s" % layer_id)
layers.get_image_diff_json(layer_id)
except rlock.LockTimeout:
log.info("Another worker is processing %s. Skipping." % layer_id)
def handle_request(layer_id, redis_conn):
'''handler for any item pulled from worker job queue
This handler is called every time the worker is able to pop a message
from the job queue filled by the registry. The worker blocks until a
message is available. This handler will then attempt to aquire a lock
for the provided layer_id and if successful, process a diff for the
layer.
If the lock for this layer_id has already been aquired for this layer
the worker will immediately timeout to block for another request.
'''
try:
# this with-context will attempt to establish a 5 minute lock
# on the key for this layer, immediately passing on LockTimeout
# if one isn't availble
with rlock.Lock(redis_conn,
"diff-worker-lock",
layer_id,
expires=60 * 5):
# first check if a cached result is already available. The registry
# already does this, but hey.
diff_data = layers.get_image_diff_cache(layer_id)
if not diff_data:
log.info("Processing diff for %s" % layer_id)
layers.get_image_diff_json(layer_id)
except rlock.LockTimeout:
log.info("Another worker is processing %s. Skipping." % layer_id)
def test_image_diff_cache(self):
layer_id = rndstr(16)
layers.set_image_diff_cache(layer_id, layer_id)
diff_json = layers.get_image_diff_cache(layer_id)
assert layer_id == diff_json
