background.py

import os
import shutil
import tempfile
import gc
import time
from uuid import uuid4
import subprocess
import logging


import firebase_admin
from firebase_admin import credentials
from firebase_admin import storage

logger = logging.getLogger("background")

use_firebase = False
if os.path.exists("firebasekey.json"):
 use_firebase = True
 if not firebase_admin._apps:
 cred = credentials.Certificate("firebasekey.json")
 firebase_admin.initialize_app(cred)

 bucket = storage.bucket("handwrite-2bb53.appspot.com")

CURRENT_Q = [] # TODO Use Queue?


def handwrite_background():
 try:
 server_dir = os.path.dirname(os.path.abspath(__file__))
 dirs = {}

 for dir_name in ["infiles", "outfiles", "status", "error"]:
 dirs[dir_name] = os.path.join(server_dir, dir_name)
 shutil.rmtree(dirs[dir_name], ignore_errors=True)
 os.makedirs(dirs[dir_name])
 logger.debug(f"Created directory: {dirs[dir_name]}")

 prev_time = time.time()
 count = 0
 while True:
 # TODO
 # We are processing one at a time
 # in batches of 3, these batches are for
 # future threading support.
 if len(CURRENT_Q) == 0:
 mtime = lambda x: os.stat(dirs["status"] + os.sep + x).st_mtime
 files = sorted(os.listdir(dirs["status"]), key=mtime)
 while len(CURRENT_Q) < 4 and files:
 CURRENT_Q.append(files.pop(0))

 if CURRENT_Q:
 name = CURRENT_Q.pop(0)
 logger.debug(f"Started font creation {name}")
 image_name = name + ".jpg"
 temp_dir = tempfile.mkdtemp()
 os.makedirs(dirs["outfiles"] + os.sep + name)

 try:
 logger.info(f"Calling handwrite for {name}")
 subprocess.check_output(
 [
 "handwrite",
 dirs["infiles"] + os.sep + image_name,
 dirs["outfiles"] + os.sep + name,
 "--directory",
 temp_dir,
 "--config",
 os.path.dirname(os.path.abspath(__file__))
 + "/default.json",
 ]
 )

 if use_firebase:
 try:
 logger.info(f"Firebase Upload Started {name}")
 metadata = {"firebaseStorageDownloadTokens": uuid4()}
 blob = bucket.blob(name)
 blob.metadata = metadata
 blob.upload_from_filename(
 dirs["infiles"] + os.sep + image_name
 )
 logger.debug(f"Firebase Upload Successful {name}")
 except:
 logger.error(f"Firebase Upload Failed {name}")
 logger.debug(f"Font Generation Complete {name}")

 except:
 open(dirs["error"] + os.sep + name, "w").close()
 logger.info(f"Unable to process Image: {name}")

 os.remove(dirs["infiles"] + os.sep + image_name)
 os.remove(dirs["status"] + os.sep + name)
 shutil.rmtree(temp_dir)
 logger.debug(f"Post Process Cleanup Completed {name}")

 # count += 1

 # if count == 6:
 # gc.collect()
 # count = 0

 if (time.time() - prev_time) / 60 > 2:
 for dir_name in ["outfiles", "error"]:
 for fd in os.listdir(dirs[dir_name]):
 path = dirs[dir_name] + os.sep + fd
 if (time.time() - os.stat(path).st_mtime) / 60 > 10:
 logger.info(f"Deleting (Timeout): {path}")
 if dir_name == "outfiles":
 shutil.rmtree(path)
 else:
 os.remove(path)
 prev_time = time.time()

 time.sleep(0.1)
 except:
 logger.exception("Background Service Crashed")