libervia-backend/sat/tools/stream.py
2022-10-31 04:04:32 +01:00

262 lines
8.6 KiB
Python

#!/usr/bin/env python3
# Libervia: an XMPP client
# Copyright (C) 2009-2021 Jérôme Poisson (goffi@goffi.org)
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# This program 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 Affero General Public License for more details.
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
""" interfaces """
from argparse import OPTIONAL
from pathlib import Path
from typing import Callable, Optional, Union
import uuid
import os
from zope import interface
from sat.core import exceptions
from sat.core.constants import Const as C
from sat.core.core_types import SatXMPPEntity
from sat.core.log import getLogger
from twisted.protocols import basic
from twisted.internet import interfaces
from sat.core.sat_main import SAT
log = getLogger(__name__)
class IStreamProducer(interface.Interface):
def startStream(consumer):
"""start producing the stream
@return (D): deferred fired when stream is finished
"""
pass
class SatFile:
"""A file-like object to have high level files manipulation"""
# TODO: manage "with" statement
def __init__(
self,
host: SAT,
client: SatXMPPEntity,
path: Union[str, Path],
mode: str = "rb",
uid: Optional[str] = None,
size: Optional[int] = None,
data_cb: Optional[Callable] = None,
auto_end_signals: bool = True,
check_size_with_read: bool = False,
pre_close_cb: Optional[Callable]=None
) -> None:
"""
@param host: %(doc_host)s
@param path(Path, str): path to the file to get or write to
@param mode(str): same as for built-in "open" function
@param uid(unicode, None): unique id identifing this progressing element
This uid will be used with self.host.progressGet
will be automaticaly generated if None
@param size(None, int): size of the file (when known in advance)
@param data_cb(None, callable): method to call on each data read/write
can be used to do processing like calculating hash.
if data_cb return a non None value, it will be used instead of the
data read/to write
@param auto_end_signals(bool): if True, progressFinished and progressError signals
are automatically sent.
if False, you'll have to call self.progressFinished and self.progressError
yourself.
progressStarted signal is always sent automatically
@param check_size_with_read(bool): if True, size will be checked using number of
bytes read or written. This is useful when data_cb modifiy len of file.
@param pre_close_cb:
"""
self.host = host
self.profile = client.profile
self.uid = uid or str(uuid.uuid4())
self._file = open(path, mode)
self.size = size
self.data_cb = data_cb
self.auto_end_signals = auto_end_signals
self.pre_close_cb = pre_close_cb
metadata = self.getProgressMetadata()
self.host.registerProgressCb(
self.uid, self.getProgress, metadata, profile=client.profile
)
self.host.bridge.progressStarted(self.uid, metadata, client.profile)
self._transfer_count = 0 if check_size_with_read else None
@property
def check_size_with_read(self):
return self._transfer_count is not None
@check_size_with_read.setter
def check_size_with_read(self, value):
if value and self._transfer_count is None:
self._transfer_count = 0
else:
self._transfer_count = None
def checkSize(self):
"""Check that current size correspond to given size
must be used when the transfer is supposed to be finished
@return (bool): True if the position is the same as given size
@raise exceptions.NotFound: size has not be specified
"""
if self.check_size_with_read:
position = self._transfer_count
else:
position = self._file.tell()
if self.size is None:
raise exceptions.NotFound
return position == self.size
def close(self, progress_metadata=None, error=None):
"""Close the current file
@param progress_metadata(None, dict): metadata to send with _onProgressFinished
message
@param error(None, unicode): set to an error message if progress was not
successful
mutually exclusive with progress_metadata
error can happen even if error is None, if current size differ from given size
"""
if self._file.closed:
return # avoid double close (which is allowed) error
if self.pre_close_cb is not None:
self.pre_close_cb()
if error is None:
try:
size_ok = self.checkSize()
except exceptions.NotFound:
size_ok = True
if not size_ok:
error = "declared and actual size mismatch"
log.warning(error)
progress_metadata = None
self._file.close()
if self.auto_end_signals:
if error is None:
self.progressFinished(progress_metadata)
else:
assert progress_metadata is None
self.progressError(error)
self.host.removeProgressCb(self.uid, self.profile)
if error is not None:
log.error(f"file {self._file} closed with an error: {error}")
@property
def closed(self):
return self._file.closed
def progressFinished(self, metadata=None):
if metadata is None:
metadata = {}
self.host.bridge.progressFinished(self.uid, metadata, self.profile)
def progressError(self, error):
self.host.bridge.progressError(self.uid, error, self.profile)
def flush(self):
self._file.flush()
def write(self, buf):
if self.data_cb is not None:
ret = self.data_cb(buf)
if ret is not None:
buf = ret
if self._transfer_count is not None:
self._transfer_count += len(buf)
self._file.write(buf)
def read(self, size=-1):
read = self._file.read(size)
if self.data_cb is not None:
ret = self.data_cb(read)
if ret is not None:
read = ret
if self._transfer_count is not None:
self._transfer_count += len(read)
return read
def seek(self, offset, whence=os.SEEK_SET):
self._file.seek(offset, whence)
def tell(self):
return self._file.tell()
@property
def mode(self):
return self._file.mode
def getProgressMetadata(self):
"""Return progression metadata as given to progressStarted
@return (dict): metadata (check bridge for documentation)
"""
metadata = {"type": C.META_TYPE_FILE}
mode = self._file.mode
if "+" in mode:
pass # we have no direction in read/write modes
elif mode in ("r", "rb"):
metadata["direction"] = "out"
elif mode in ("w", "wb"):
metadata["direction"] = "in"
elif "U" in mode:
metadata["direction"] = "out"
else:
raise exceptions.InternalError
metadata["name"] = self._file.name
return metadata
def getProgress(self, progress_id, profile):
ret = {"position": self._file.tell()}
if self.size:
ret["size"] = self.size
return ret
@interface.implementer(IStreamProducer)
@interface.implementer(interfaces.IConsumer)
class FileStreamObject(basic.FileSender):
def __init__(self, host, client, path, **kwargs):
"""
A SatFile will be created and put in self.file_obj
@param path(unicode): path to the file
@param **kwargs: kw arguments to pass to SatFile
"""
self.file_obj = SatFile(host, client, path, **kwargs)
def registerProducer(self, producer, streaming):
pass
def startStream(self, consumer):
return self.beginFileTransfer(self.file_obj, consumer)
def write(self, data):
self.file_obj.write(data)
def close(self, *args, **kwargs):
self.file_obj.close(*args, **kwargs)