function.py

# Copyright 2020-2025 ETH Zurich and the SeBS authors. All rights reserved.
# Cloudflare Workers differ from the default Python version: the Workers
# Python runtime is Pyodide-based and does not support `urllib.request`, so
# we download via Pyodide's async `pyfetch` and wrap it with `run_sync` to
# keep the synchronous handler signature.

import datetime
import os

from pyodide.ffi import run_sync
from pyodide.http import pyfetch

from . import storage
client = storage.storage.get_instance()

SEBS_USER_AGENT = "SeBS/1.2 (https://github.com/spcl/serverless-benchmarks) SeBS Benchmark Suite/1.2"

async def do_request(url, download_path):
    headers = {'User-Agent': SEBS_USER_AGENT}

    res = await pyfetch(url, headers=headers)
    bs = await res.bytes()
    
    with open(download_path, 'wb') as f:
        f.write(bs)

def handler(event):

    bucket = event.get('bucket').get('bucket')
    output_prefix = event.get('bucket').get('output')
    url = event.get('object').get('url')
    name = os.path.basename(url)
    download_path = '/tmp/{}'.format(name)

    process_begin = datetime.datetime.now()

    run_sync(do_request(url, download_path))

    size = os.path.getsize(download_path)
    process_end = datetime.datetime.now()

    upload_begin = datetime.datetime.now()
    key_name = client.upload(bucket, os.path.join(output_prefix, name), download_path)
    upload_end = datetime.datetime.now()

    process_time = (process_end - process_begin) / datetime.timedelta(microseconds=1)
    upload_time = (upload_end - upload_begin) / datetime.timedelta(microseconds=1)
    return {
            'result': {
                'bucket': bucket,
                'url': url,
                'key': key_name
            },
            'measurement': {
                'download_time': 0,
                'download_size': 0,
                'upload_time': upload_time,
                'upload_size': size,
                'compute_time': process_time
            }
    }