3.4 Handling Streaming Requests
In this section, we will create a new HTTP trigger that returns a streaming response based on the request body of the POST request.
Stream The Numbers
Create a new file named http_trigger_stream_numbers.py
in the awel_tutorial
directory
from dbgpt._private.pydantic import BaseModel, Field
from dbgpt.core.awel import DAG, HttpTrigger, StreamifyAbsOperator, setup_dev_environment
from typing import AsyncIterator
class TriggerReqBody(BaseModel):
n: int = Field(..., description="The number of integers to be streamed")
class NumberProducerOperator(StreamifyAbsOperator[TriggerReqBody, int]):
"""Create a stream of numbers from 0 to `n-1`"""
async def streamify(self, req: TriggerReqBody) -> AsyncIterator[int]:
for i in range(req.n):
yield str(i) + "\n"
with DAG("awel_stream_numbers") as dag:
trigger_task = HttpTrigger(
endpoint="/awel_tutorial/stream_numbers",
methods="POST",
request_body=TriggerReqBody,
status_code=200,
streaming_predict_func=lambda x: True
)
task = NumberProducerOperator()
trigger_task >> task
setup_dev_environment([dag], port=5555)
And run the following command to execute the code:
poetry run python awel_tutorial/http_trigger_stream_numbers.py
Now, open a new terminal and run the following command to send a POST request to the server:
curl -X POST \
"http://127.0.0.1:5555/api/v1/awel/trigger/awel_tutorial/stream_numbers" \
-H "Content-Type: application/json" \
-d '{"n": 5}'
The output should look like this:
0
1
2
3
4
Then you can stop the server by pressing Ctrl+C
.
In this example, we created a HttpTrigger
operator with a streaming predict function
which is used to determine whether to stream the response(it always returns True
in this example).