pilbox_lcoal_image_handler.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

from os import environ, path, makedirs
import imghdr
from datetime import datetime, timedelta
from concurrent.futures import ThreadPoolExecutor

from tornado import gen
from tornado.concurrent import run_on_executor
from pilbox.app import ImageHandler as _ImageHandler, Image


class ImageHandler(_ImageHandler):
    executor = ThreadPoolExecutor(4)

    def initialize(self, path):
        self._storage_path = path
        self.args = self.request.arguments.copy()
        if isinstance(self.args.get("w")):
            self.args["w"] = self.args["w"][0]
        if isinstance(self.args.get("h")):
            self.args["h"] = self.args["h"][0]
        if "opt" not in self.args:
            self.args["opt"] = 1
        if "quality" not in self.args:
            self.args["quality"] = 72

    def get_argument(self, name, default=None):
        return self.args.get(name, default)

    def _get_operations(self):
        default_operation = "resize"
        if "w" not in self.request.arguments and "h" not in self.request.arguments:
            default_operation = "noop"
        return self.get_argument(
            "op", self.settings.get("operation") or default_operation).split(",")

    @gen.coroutine
    def get(self, slug):
        img_path = path.join(self._storage_path, slug)
        if not path.exists(img_path):
            self.set_status(404)
            return
        orig_format = imghdr.what(img_path)
        with open(img_path, "rb") as srcfile:
            outfile, outfile_format = yield self._process_image(srcfile)
            now = datetime.now()
            expired = now + timedelta(days=10*365)
            headers = {
                "Content-Type": self._FORMAT_TO_MIME.get(orig_format),
                "Expires": expired.strftime("%a, %d %b %Y %H:%M:%S GMT"),
                "Last-Modified": now.strftime("%a, %d %b %Y %H:%M:%S GMT"),
            }
            self._set_headers(headers, outfile_format)
            for block in iter(lambda: outfile.read(65536), b""):
                self.write(block)
            outfile.close()

    @run_on_executor
    def _process_image(self, buffer):
        ops = self._get_operations()
        image = Image(buffer)
        if "noop" not in ops:
            for operation in ops:
                if operation == "resize":
                    self._image_resize(image)
                elif operation == "rotate":
                    self._image_rotate(image)
                elif operation == "region":
                    self._image_region(image)
        return (self._image_save(image), image.img.format)