model-service/model_service/views/svm_view.py

#!/usr/bin/env python3
import tempfile
import os
from flask import request, jsonify, current_app, abort, Response, url_for
from flask_classful import FlaskView, route
from model import db, Default, AIModel, AIModelType, SVMDetails
from minio.error import NoSuchKey
from schemas import AIModelSchema, InfoSchema
from marshmallow.exceptions import ValidationError
from utils import storage, ensure_buckets, multipart_required
from pyAudioAnalysis.audioTrainTest import load_model


class SVMView(FlaskView):
    route_base = 'svm'

    aimodel_schema = AIModelSchema(many=False)
    info_schema = InfoSchema(many=False)

    MODEL_DIRECTORY = "model/"
    MEANS_DIRECTORY = "means/"

    @multipart_required
    def post(self):

        # get important data from the request
        try:
            info = self.info_schema.loads(request.form.get('info'))
        except ValidationError as e:
            abort(400, str(e))

        # check for conflict
        m = AIModel.query.filter_by(id=info['id']).first()
        if m:
            abort(409)

        # get and validate file
        model_file = request.files['modelFile']

        if model_file.content_length <= 0:
            abort(411, f"Content length for modelFile is not a positive integer or missing.")

        means_file = request.files['meansFile']

        if means_file.content_length <= 0:
            abort(411, f"Content length for meansFile is not a positive integer or missing.")

        # create bucket if necessary
        ensure_buckets()

        # Temporarily save the file, because pyAudioAnalysis can only read files
        temp_model_handle, temp_model_filename = tempfile.mkstemp()
        temp_means_filename = temp_model_filename + "MEANS"

        os.close(temp_model_handle)  # BRUUUUH

        model_file.save(temp_model_filename)
        means_file.save(temp_means_filename)

        try:

            _, _, _, classes, mid_window, mid_step, short_window, short_step, compute_beat \
                = load_model(temp_model_filename)

            if info['target_class_name'] not in classes:
                abort(400, f"This model does not have a class named {info['target_class_name']}")

            # Because of pyAudiomeme the files already saved, so we just use the file uploader functions
            storage.connection.fput_object(
                current_app.config['MINIO_SVM_BUCKET_NAME'],
                self.MODEL_DIRECTORY + str(info['id']),
                temp_model_filename
            )

            storage.connection.fput_object(
                current_app.config['MINIO_SVM_BUCKET_NAME'],
                self.MEANS_DIRECTORY + str(info['id']),
                temp_means_filename
            )

        finally:
            os.remove(temp_model_filename)
            os.remove(temp_means_filename)

        m = AIModel(id=info['id'], type=AIModelType.svm, target_class_name=info['target_class_name'])

        d = SVMDetails(
            aimodel=m,
            mid_window=mid_window,
            mid_step=mid_step,
            short_window=short_window,
            short_step=short_step,
            compute_beat=compute_beat
        )

        db.session.add(m)
        db.session.add(d)
        db.session.commit()

        return jsonify(self.aimodel_schema.dump(m)), 200

    def delete(self, id_: str):

        if id_ == "$default":
            default = Default.query.filter_by(type=AIModelType.svm).first_or_404()
            m = default.aimodel
        else:
            m = AIModel.query.filter_by(type=AIModelType.svm, id=id_).first_or_404()

        storage.connection.remove_object(current_app.config['MINIO_SVM_BUCKET_NAME'], self.MEANS_DIRECTORY + str(m.id))
        storage.connection.remove_object(current_app.config['MINIO_SVM_BUCKET_NAME'], self.MODEL_DIRECTORY + str(m.id))

        db.session.delete(m)
        db.session.commit()

        return '', 204

    # builtin file proxy
    @route('<id_>/file')
    def get_file(self, id_: str):

        if id_ == "$default":
            default = Default.query.filter_by(type=AIModelType.svm).first_or_404()
            m = default.aimodel
        else:
            m = AIModel.query.filter_by(type=AIModelType.svm, id=id_).first_or_404()

        if "means" in request.args:
            path = self.MEANS_DIRECTORY + str(m.id)
        else:
            path = self.MODEL_DIRECTORY + str(m.id)

        try:
            data = storage.connection.get_object(current_app.config['MINIO_SVM_BUCKET_NAME'], path)
        except NoSuchKey:
            abort(500, "The ID is stored in the database but not int the Object Store")

        return Response(data.stream(), mimetype=data.headers['Content-type'])