qutebrowser/qutebrowser/browser/downloads.py
2014-08-26 20:25:11 +02:00

416 lines
16 KiB
Python

# vim: ft=python fileencoding=utf-8 sts=4 sw=4 et:
# Copyright 2014 Florian Bruhin (The Compiler) <mail@qutebrowser.org>
#
# This file is part of qutebrowser.
#
# qutebrowser is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# qutebrowser is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with qutebrowser. If not, see <http://www.gnu.org/licenses/>.
"""Download manager."""
import os
import os.path
import functools
import collections
from PyQt5.QtCore import pyqtSlot, pyqtSignal, QObject, QTimer, QStandardPaths
from PyQt5.QtNetwork import QNetworkRequest, QNetworkReply
from qutebrowser.config import config
from qutebrowser.commands import utils as cmdutils
from qutebrowser.commands import exceptions as cmdexc
from qutebrowser.utils import message, http, usertypes, log, utils, qtutils
class DownloadItem(QObject):
"""A single download currently running.
Class attributes:
SPEED_REFRESH_INTERVAL: How often to refresh the speed, in msec.
SPEED_AVG_WINDOW: How many seconds of speed data to average to
estimate the remaining time.
Attributes:
reply: The QNetworkReply associated with this download.
percentage: How many percent were downloaded successfully.
None if unknown.
bytes_done: How many bytes there are already downloaded.
bytes_total: The total count of bytes.
None if the total is unknown.
speed: The current download speed, in bytes per second.
remaining_time: The time remaining for the download.
None if not enough data is available yet.
fileobj: The file object to download the file to.
filename: The filename of the download.
is_cancelled: Whether the download was cancelled.
speed_avg: A rolling average of speeds.
_last_done: The count of bytes which where downloaded when calculating
the speed the last time.
Signals:
data_changed: The downloads metadata changed.
finished: The download was finished.
cancelled: The download was cancelled.
error: An error with the download occured.
arg: The error message as string.
"""
SPEED_REFRESH_INTERVAL = 500
SPEED_AVG_WINDOW = 30
data_changed = pyqtSignal()
finished = pyqtSignal()
error = pyqtSignal(str)
cancelled = pyqtSignal()
def __init__(self, reply, parent=None):
"""Constructor.
Args:
reply: The QNetworkReply to download.
"""
super().__init__(parent)
self.reply = reply
self.bytes_total = None
self.speed = 0
self.basename = '???'
samples = int(self.SPEED_AVG_WINDOW *
(1000 / self.SPEED_REFRESH_INTERVAL))
self.speed_avg = collections.deque(maxlen=samples)
self.fileobj = None
self.filename = None
self.is_cancelled = False
self._do_delayed_write = False
self.bytes_done = 0
self._last_done = 0
reply.setReadBufferSize(16 * 1024 * 1024)
reply.downloadProgress.connect(self.on_download_progress)
reply.finished.connect(self.on_reply_finished)
reply.error.connect(self.on_reply_error)
reply.readyRead.connect(self.on_ready_read)
# We could have got signals before we connected slots to them.
# Here no signals are connected to the DownloadItem yet, so we use a
# singleShot QTimer to emit them after they are connected.
if reply.error() != QNetworkReply.NoError:
QTimer.singleShot(0, lambda: self.error.emit(reply.errorString()))
if reply.isFinished():
QTimer.singleShot(0, self.finished.emit)
self.timer = usertypes.Timer(self, 'speed_refresh')
self.timer.timeout.connect(self.update_speed)
self.timer.setInterval(self.SPEED_REFRESH_INTERVAL)
self.timer.start()
def __repr__(self):
return '<{} "{}">'.format(self.__class__.__name__, self.basename)
def __str__(self):
"""Get the download as a string.
Example: foo.pdf [699.2kB/s|0.34|16%|4.253/25.124]
"""
speed = utils.format_size(self.speed, suffix='B/s')
down = utils.format_size(self.bytes_done, suffix='B')
if all(e is None for e in (self.percentage, self.remaining_time,
self.bytes_total)):
return ('{name} [{speed:>10}|{down}]'.format(
name=self.basename, speed=speed, down=down))
perc = '??' if self.percentage is None else round(self.percentage)
remaining = (utils.format_seconds(self.remaining_time)
if self.remaining_time is not None else '?')
total = utils.format_size(self.bytes_total, suffix='B')
return ('{name} [{speed:>10}|{remaining:>5}|{perc:>2}%|'
'{down}/{total}]'.format(name=self.basename, speed=speed,
remaining=remaining, perc=perc,
down=down, total=total))
def _die(self, msg):
"""Abort the download and emit an error."""
self.error.emit(msg)
self.reply.abort()
self.reply.deleteLater()
if self.fileobj is not None:
try:
self.fileobj.close()
except OSError as e:
self.error.emit(e.strerror)
self.finished.emit()
@property
def percentage(self):
"""Property to get the current download percentage."""
if self.bytes_total == 0 or self.bytes_total is None:
return None
else:
return 100 * self.bytes_done / self.bytes_total
@property
def remaining_time(self):
"""Property to get the remaining download time in seconds."""
if self.bytes_total is None or not self.speed_avg:
# No average yet or we don't know the total size.
return None
remaining_bytes = self.bytes_total - self.bytes_done
avg = sum(self.speed_avg) / len(self.speed_avg)
if avg == 0:
# Download stalled
return None
else:
return remaining_bytes / avg
def bg_color(self):
"""Background color to be shown."""
start = config.get('colors', 'downloads.bg.start')
stop = config.get('colors', 'downloads.bg.stop')
system = config.get('colors', 'downloads.bg.system')
if self.percentage is None:
return start
else:
return utils.interpolate_color(start, stop, self.percentage,
system)
def cancel(self):
"""Cancel the download."""
log.downloads.debug("cancelled")
self.cancelled.emit()
self.is_cancelled = True
self.reply.abort()
self.reply.deleteLater()
if self.fileobj is not None:
self.fileobj.close()
if self.filename is not None and os.path.exists(self.filename):
os.remove(self.filename)
self.finished.emit()
def set_filename(self, filename):
"""Set the filename to save the download to.
Args:
filename: The full filename to save the download to.
None: special value to stop the download.
"""
if os.path.isabs(filename):
target = os.path.expanduser(filename)
else:
download_dir = config.get('storage', 'download-directory')
if download_dir is None:
download_dir = utils.get_standard_dir(
QStandardPaths.DownloadLocation)
target = os.path.join(download_dir, filename)
log.downloads.debug("Setting filename to {}".format(filename))
if self.filename is not None:
raise ValueError("Filename was already set! filename: {}, "
"existing: {}".format(filename, self.filename))
self.filename = target
self.basename = os.path.basename(target)
try:
self.fileobj = open(target, 'wb')
if self._do_delayed_write:
# Downloading to the buffer in RAM has already finished so we
# write out the data and clean up now.
self.delayed_write()
else:
# Since the buffer already might be full, on_ready_read might
# not be called at all anymore, so we force it here to flush
# the buffer and continue receiving new data.
self.on_ready_read()
except OSError as e:
self._die(e.strerror)
def delayed_write(self):
"""Write buffered data to disk and finish the QNetworkReply."""
log.downloads.debug("Doing delayed write...")
self._do_delayed_write = False
self.fileobj.write(self.reply.readAll())
self.fileobj.close()
self.reply.close()
self.reply.deleteLater()
self.finished.emit()
log.downloads.debug("Download finished")
@pyqtSlot(int, int)
def on_download_progress(self, bytes_done, bytes_total):
"""Upload local variables when the download progress changed.
Args:
bytes_done: How many bytes are downloaded.
bytes_total: How many bytes there are to download in total.
"""
if bytes_total == -1:
bytes_total = None
self.bytes_done = bytes_done
self.bytes_total = bytes_total
self.data_changed.emit()
@pyqtSlot()
def on_reply_finished(self):
"""Clean up when the download was finished.
Note when this gets called, only the QNetworkReply has finished. This
doesn't mean the download (i.e. writing data to the disk) is finished
as well. Therefore, we can't close() the QNetworkReply in here yet.
"""
self.bytes_done = self.bytes_total
self.timer.stop()
if self.is_cancelled:
return
log.downloads.debug("Reply finished, fileobj {}".format(self.fileobj))
if self.fileobj is None:
# We'll handle emptying the buffer and cleaning up as soon as the
# filename is set.
self._do_delayed_write = True
else:
# We can do a "delayed" write immediately to empty the buffer and
# clean up.
self.delayed_write()
@pyqtSlot()
def on_ready_read(self):
"""Read available data and save file when ready to read."""
if self.fileobj is None:
# No filename has been set yet, so we don't empty the buffer.
return
try:
self.fileobj.write(self.reply.readAll())
except OSError as e:
self._die(e.strerror)
@pyqtSlot(int)
def on_reply_error(self, code):
"""Handle QNetworkReply errors."""
if code == QNetworkReply.OperationCanceledError:
return
else:
self.error.emit(self.reply.errorString())
@pyqtSlot()
def update_speed(self):
"""Recalculate the current download speed."""
delta = self.bytes_done - self._last_done
self.speed = delta * 1000 / self.SPEED_REFRESH_INTERVAL
self.speed_avg.append(self.speed)
self._last_done = self.bytes_done
self.data_changed.emit()
class DownloadManager(QObject):
"""Manager for running downloads.
Attributes:
downloads: A list of active DownloadItems.
questions: A list of Question objects to not GC them.
Signals:
download_about_to_be_added: A new download will be added.
arg: The index of the new download.
download_added: A new download was added.
download_about_to_be_finished: A download will be finished and removed.
arg: The index of the new download.
download_finished: A download was finished and removed.
data_changed: The data to be displayed in a model changed.
arg: The index of the download which changed.
"""
download_about_to_be_added = pyqtSignal(int)
download_added = pyqtSignal()
download_about_to_be_finished = pyqtSignal(int)
download_finished = pyqtSignal()
data_changed = pyqtSignal(int)
def __init__(self, parent=None):
super().__init__(parent)
self.downloads = []
self.questions = []
def __repr__(self):
return '<{}>'.format(self.__class__.__name__)
@pyqtSlot('QUrl', 'QWebPage')
def get(self, url, page):
"""Start a download with a link URL.
Args:
url: The URL to get, as QUrl
page: The QWebPage to get the download from.
"""
qtutils.ensure_valid(url)
req = QNetworkRequest(url)
reply = page.networkAccessManager().get(req)
self.fetch(reply)
@cmdutils.register(instance='downloadmanager')
def cancel_download(self, count=1):
"""Cancel the first/[count]th download."""
if count == 0:
return
try:
download = self.downloads[count - 1]
except IndexError:
raise cmdexc.CommandError("There's no download {}!".format(count))
download.cancel()
@pyqtSlot('QNetworkReply')
def fetch(self, reply):
"""Download a QNetworkReply to disk.
Args:
reply: The QNetworkReply to download.
"""
_inline, suggested_filename = http.parse_content_disposition(reply)
log.downloads.debug("fetch: {} -> {}".format(reply.url(),
suggested_filename))
download = DownloadItem(reply, self)
download.finished.connect(
functools.partial(self.on_finished, download))
download.data_changed.connect(
functools.partial(self.on_data_changed, download))
download.error.connect(self.on_error)
download.basename = suggested_filename
self.download_about_to_be_added.emit(len(self.downloads) + 1)
self.downloads.append(download)
self.download_added.emit()
q = usertypes.Question(self)
q.text = "Save file to:"
q.mode = usertypes.PromptMode.text
q.default = suggested_filename
q.answered.connect(download.set_filename)
q.cancelled.connect(download.cancel)
q.completed.connect(q.deleteLater)
q.destroyed.connect(functools.partial(self.questions.remove, q))
self.questions.append(q)
download.cancelled.connect(q.abort)
message.instance().ask(q, blocking=False)
@pyqtSlot(DownloadItem)
def on_finished(self, download):
"""Remove finished download."""
log.downloads.debug("on_finished: {}".format(download))
idx = self.downloads.index(download)
self.download_about_to_be_finished.emit(idx)
del self.downloads[idx]
self.download_finished.emit()
download.deleteLater()
@pyqtSlot(DownloadItem)
def on_data_changed(self, download):
"""Emit data_changed signal when download data changed."""
idx = self.downloads.index(download)
self.data_changed.emit(idx)
@pyqtSlot(str)
def on_error(self, msg):
"""Display error message on download errors."""
message.error("Download error: {}".format(msg))