%PDF-
%PDF-
Mini Shell
Mini Shell
#!/usr/bin/env python3
# License: GPL v3 Copyright: 2021, Kovid Goyal <kovid at kovidgoyal.net>
import os
from queue import Queue
from threading import Thread
from calibre import detect_ncpus
from calibre.utils.img import encode_jpeg, optimize_jpeg
def compress_worker(input_queue, output_queue, jpeg_quality):
while True:
task = input_queue.get()
if task is None:
break
book_id, path = task
try:
if jpeg_quality >= 100:
stderr = optimize_jpeg(path)
else:
stderr = encode_jpeg(path, jpeg_quality)
except Exception:
import traceback
stderr = traceback.format_exc()
if stderr:
output_queue.put((book_id, stderr))
else:
try:
sz = os.path.getsize(path)
except OSError as err:
sz = str(err)
output_queue.put((book_id, sz))
def compress_covers(path_map, jpeg_quality, progress_callback):
input_queue = Queue()
output_queue = Queue()
num_workers = detect_ncpus()
sz_map = {}
for book_id, (path, sz) in path_map.items():
input_queue.put((book_id, path))
sz_map[book_id] = sz
workers = [
Thread(target=compress_worker, args=(input_queue, output_queue, jpeg_quality), daemon=True, name=f'CCover-{i}')
for i in range(num_workers)
]
[w.start() for w in workers]
pending = set(path_map)
while pending:
book_id, new_sz = output_queue.get()
pending.remove(book_id)
progress_callback(book_id, sz_map[book_id], new_sz)
for w in workers:
input_queue.put(None)
for w in workers:
w.join()
Zerion Mini Shell 1.0