##// END OF EJS Templates
Prevent qtconsole frontend freeze on lots of output....
Prevent qtconsole frontend freeze on lots of output. The output from the kernel is now clipped to last `buffer_size` before displaying and a timer is used to flush the pending output text instead of attempting to display text on every stream output from kernel. The timer interval is adjusted based on actual time taken to append a screenful of text to widget. This throttles the widget repaints and avoids choking the Qt event loop leaving time to handle other Qt events. Test cases: In [1]: for i in xrange(1000000): print i In [2]: range(100000) Without this commit the first input causes the qtconsole frontend to freeze, not responding to `Ctrl+C`.

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nbjson.py
72 lines | 2.0 KiB | text/x-python | PythonLexer
"""Read and write notebooks in JSON format.
Authors:
* Brian Granger
"""
#-----------------------------------------------------------------------------
# Copyright (C) 2008-2011 The IPython Development Team
#
# Distributed under the terms of the BSD License. The full license is in
# the file COPYING, distributed as part of this software.
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
import copy
import json
from .nbbase import from_dict
from .rwbase import (
NotebookReader, NotebookWriter, restore_bytes, rejoin_lines, split_lines
)
from IPython.utils import py3compat
#-----------------------------------------------------------------------------
# Code
#-----------------------------------------------------------------------------
class BytesEncoder(json.JSONEncoder):
"""A JSON encoder that accepts b64 (and other *ascii*) bytestrings."""
def default(self, obj):
if isinstance(obj, bytes):
return obj.decode('ascii')
return json.JSONEncoder.default(self, obj)
class JSONReader(NotebookReader):
def reads(self, s, **kwargs):
nb = json.loads(s, **kwargs)
nb = self.to_notebook(nb, **kwargs)
return nb
def to_notebook(self, d, **kwargs):
return restore_bytes(rejoin_lines(from_dict(d)))
class JSONWriter(NotebookWriter):
def writes(self, nb, **kwargs):
kwargs['cls'] = BytesEncoder
kwargs['indent'] = 1
kwargs['sort_keys'] = True
kwargs['separators'] = (',',': ')
if kwargs.pop('split_lines', True):
nb = split_lines(copy.deepcopy(nb))
return py3compat.str_to_unicode(json.dumps(nb, **kwargs), 'utf-8')
_reader = JSONReader()
_writer = JSONWriter()
reads = _reader.reads
read = _reader.read
to_notebook = _reader.to_notebook
write = _writer.write
writes = _writer.writes