cic-internal-integration/apps/cic-eth/cic_eth/server/celery.py

import json
import logging
import sys
import uuid

import redis
from cic_eth.api.api_task import Api

log = logging.getLogger(__name__)


def create_celery_wrapper(chain_spec,
                          celery_queue,
                          redis_host,
                          redis_port,
                          redis_db,
                          redis_timeout):
    def call(method, *args, catch=1, **kwargs):
        """ Creates a redis channel and calls `cic_eth.api` with the provided `method` and `*args`. Returns the result of the api call. Catch allows you to specify how many messages to catch before returning.
        """
        log.debug(f"Using chainspec: {chain_spec}")
        redis_channel = str(uuid.uuid4())
        r = redis.Redis(redis_host, redis_port, redis_db)
        ps = r.pubsub()
        ps.subscribe(redis_channel)
        api = Api(
            chain_spec,
            queue=celery_queue,
            callback_param='{}:{}:{}:{}'.format(
                redis_host, redis_port, redis_db, redis_channel),
            callback_task='cic_eth.callbacks.redis.redis',
            callback_queue=celery_queue,
        )
        getattr(api, method)(*args, **kwargs)

        ps.get_message()
        try:
            data = []
            if catch == 1:
                message = ps.get_message(timeout=redis_timeout)
                data = json.loads(message['data'])["result"]
            else:
                for _i in range(catch):
                    message = ps.get_message(
                        timeout=redis_timeout)
                    result = json.loads(message['data'])["result"]
                    data.append(result)

        except TimeoutError as e:
            sys.stderr.write(
                f"cic_eth.api.{method}({args}, {kwargs}) timed out:\n {e}")
            raise e
        except Exception as e:
            sys.stderr.write(
                f'Unable to parse Data:\n{data}\n Error:\n{e}')
            raise e

        log.debug(
            f"cic_eth.api.{method}(args={args}, kwargs={kwargs})\n {data}")

        ps.unsubscribe()
        return data
    return call