trustgraph/trustgraph-base/trustgraph/base/consumer.py
2025-04-15 23:09:32 +01:00

134 lines
3.7 KiB
Python

import asyncio
import time
from .. exceptions import TooManyRequests
class Consumer:
def __init__(
self, taskgroup, client, queue, subscriber, schema,
handler, rate_limit_retry_time = 10,
rate_limit_timeout = 7200, metrics = None,
start_of_messages=False,
):
self.taskgroup = taskgroup
self.client = client
self.queue = queue
self.subscriber = subscriber
self.schema = schema
self.handler = handler
self.rate_limit_retry_time = rate_limit_retry_time
self.rate_limit_timeout = rate_limit_timeout
self.start_of_messages = start_of_messages
self.running = True
self.task = None
self.metrics = metrics
async def stop(self):
self.running = False
async def start(self):
self.running = True
self.consumer = self.client.subscribe(
self.queue, self.subscriber, self.schema,
start_of_messages = self.start_of_messages,
)
print("Subscribed.", flush=True)
# Puts it in the stopped state, the run thread should set running
if self.metrics:
self.metrics.state("stopped")
self.task = self.taskgroup.create_task(self.run())
print("Subscriber started", flush=True)
async def run(self):
if self.metrics:
self.metrics.state("running")
while self.running:
msg = await asyncio.to_thread(self.consumer.receive)
expiry = time.time() + self.rate_limit_timeout
# This loop is for retry on rate-limit / resource limits
while True:
if time.time() > expiry:
print("Gave up waiting for rate-limit retry", flush=True)
# Message failed to be processed, this causes it to
# be retried
self.consumer.negative_acknowledge(msg)
if self.metrics:
self.metrics.process("error")
# Break out of retry loop, processes next message
break
try:
print("Handle...", flush=True)
if self.metrics:
with self.metrics.record_time():
await self.handler(msg, self)
else:
await self.handler(msg, self.consumer)
print("Handled.", flush=True)
# Acknowledge successful processing of the message
self.consumer.acknowledge(msg)
if self.metrics:
self.metrics.process("success")
# Break out of retry loop
break
except TooManyRequests:
print("TooManyRequests: will retry...", flush=True)
# FIXME
if self.metrics:
self.metrics.rate_limit()
# Sleep
await asyncio.sleep(self.rate_limit_retry)
# Contine from retry loop, just causes a reprocessing
continue
except Exception as e:
print("Exception:", e, flush=True)
# Message failed to be processed, this causes it to
# be retried
self.consumer.negative_acknowledge(msg)
if self.metrics:
self.metrics.process("error")
# Break out of retry loop, processes next message
break
if self.metrics:
self.metrics.state("stopped")