cv-analysis-service/cv_analysis/server/stream.py

import gzip
from operator import itemgetter
from typing import Callable

from funcy import lmap
from pyinfra.server.utils import make_streamable_and_wrap_in_packing_logic

from cv_analysis.server.format import make_formatter
from cv_analysis.utils.preprocessing import open_img_from_bytes


def make_streamable_analysis_fn(analysis_fn: Callable):
    """Makes an analysis function streamable for pyinfra server logic. The wrapped function then
    works with data and metadata and returns a tuple or generator of tuples with data and metadata.
    For more information about the server logic, see the PyInfra documentation.

    Args:
        analysis_fn: cv-analysis function

    Returns:
        wrapped function
    """

    def analyse(data: bytes, metadata: dict):

        image = open_img_from_bytes(gzip.decompress(data))

        dpi = metadata["image_info"]["dpi"]
        width, height, rotation = itemgetter("width", "height", "rotation")(metadata["page_info"])

        formatter = make_formatter(dpi, (width, height), rotation)

        results = map(lambda x: x.json_xywh(), analysis_fn(image))
        results = {"cells": (lmap(formatter, results))}

        return b"", {**metadata, **results}

    return make_streamable_and_wrap_in_packing_logic(analyse, batched=False)