trustgraph/trustgraph-base/trustgraph/base/consumer.py
2025-04-17 16:12:46 +01:00

181 lines
4.8 KiB
Python

import _pulsar
import asyncio
import time
from .. exceptions import TooManyRequests
class Consumer:
def __init__(
self, taskgroup, flow, client, queue, subscriber, schema,
handler, rate_limit_retry_time = 10,
rate_limit_timeout = 7200, metrics = None,
start_of_messages=False,
):
self.taskgroup = taskgroup
self.flow = flow
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
self.consumer = None
def __del__(self):
self.running = False
if hasattr(self, "consumer"):
self.consumer.close()
async def stop(self):
self.running = False
await self.task
async def start(self):
self.running = 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())
async def run(self):
if self.metrics:
self.metrics.state("stopped")
while self.running:
try:
print(self.queue, "subscribing...", flush=True)
self.consumer = await asyncio.to_thread(
self.client.subscribe,
queue = self.queue, subscriber = self.subscriber,
schema = self.schema,
start_of_messages = self.start_of_messages
)
except Exception as e:
print("Exception:", e, flush=True)
await asyncio.sleep(2)
continue
print(self.queue, "subscribed", flush=True)
if self.metrics:
self.metrics.state("running")
try:
await self.consume()
if self.metrics:
self.metrics.state("stopped")
except Exception as e:
print("Exception:", e, flush=True)
self.consumer.close()
self.consumer = None
await asyncio.sleep(2)
continue
async def consume(self):
while self.running:
try:
msg = await asyncio.to_thread(
self.consumer.receive,
timeout_millis=2000
)
except _pulsar.Timeout:
continue
except Exception as e:
raise e
expiry = time.time() + self.rate_limit_timeout
# This loop is for retry on rate-limit / resource limits
while self.running:
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, self.flow)
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)
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