thumbnail_maker.py

# thumbnail_maker.py
import time
import os
import logging
from urllib.parse import urlparse
from urllib.request import urlretrieve

from queue import Queue
from threading import Thread

import PIL
from PIL import Image

FORMAT = '[%(threadName)15s%(asctime)25s%(levelname)10s] - %(message)s'
logging.basicConfig(filename='logfile.log', level=logging.DEBUG, format=FORMAT)


class ThumbnailMakerService(object):
    def __init__(self, home_dir='.'):
        self.home_dir = home_dir
        self.input_dir = self.home_dir + os.path.sep + 'incoming'
        self.output_dir = self.home_dir + os.path.sep + 'outgoing'
        self.img_queue = Queue()
        self.dl_queue = Queue()

    def download_image(self):
        while not self.dl_queue.empty():
            try:
                url = self.dl_queue.get(block=False)
                # download each image and save to the input dir
                img_filename = urlparse(url).path.split('/')[-1]
                urlretrieve(url, self.input_dir + os.path.sep + img_filename)
                self.img_queue.put(img_filename)

                self.dl_queue.task_done()
            except Queue.empty:
                logging.info("Queue empty")

    def download_images(self, img_url_list):
        # validate inputs
        if not img_url_list:
            return
        os.makedirs(self.input_dir, exist_ok=True)

        logging.info("beginning image downloads")

        start = time.perf_counter()
        for url in img_url_list:
            # download each image and save to the input dir
            img_filename = urlparse(url).path.split('/')[-1]
            urlretrieve(url, self.input_dir + os.path.sep + img_filename)
            self.img_queue.put(img_filename)
        end = time.perf_counter()

        self.img_queue.put(None)

        logging.info("downloaded {} images in {} seconds".format(len(img_url_list), end - start))

    def perform_resizing(self):
        os.makedirs(self.output_dir, exist_ok=True)

        logging.info("beginning image resizing")
        target_sizes = [32, 64, 200]
        num_images = len(os.listdir(self.input_dir))

        start = time.perf_counter()
        while True:
            filename = self.img_queue.get()

            if filename:
                logging.info(f'resizing image {filename}')
                orig_img = Image.open(self.input_dir + os.path.sep + filename)
                for basewidth in target_sizes:
                    img = orig_img
                    # calculate target height of the resized image to maintain the aspect ratio
                    wpercent = (basewidth / float(img.size[0]))
                    hsize = int((float(img.size[1]) * float(wpercent)))
                    # perform resizing
                    img = img.resize((basewidth, hsize), PIL.Image.LANCZOS)

                    # save the resized image to the output dir with a modified file name
                    new_filename = os.path.splitext(filename)[0] + \
                        '_' + str(basewidth) + os.path.splitext(filename)[1]
                    img.save(self.output_dir + os.path.sep + new_filename)

                os.remove(self.input_dir + os.path.sep + filename)
                logging.info(f'done resizing image: {filename}')
                self.img_queue.task_done()
            else:
                self.img_queue.task_done()
                break

        end = time.perf_counter()

        logging.info("created {} thumbnails in {} seconds".format(num_images, end - start))

    def make_thumbnails(self, img_url_list):
        logging.info("START make_thumbnails")
        start = time.perf_counter()

        for img_url in img_url_list:
            self.dl_queue.put(img_url)

        num_dl_threads = 4

        for _ in range(num_dl_threads):
            t = Thread(target=self.download_image)
            t.start()

        t2 = Thread(target=self.perform_resizing)
        t2.start()

        self.dl_queue.join()
        self.img_queue.put(None)
        t2.join()

        end = time.perf_counter()
        logging.info("END make_thumbnails in {} seconds".format(end - start))