140 lines
4.8 KiB
Python
140 lines
4.8 KiB
Python
import sys
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from traceback import format_exc, extract_tb
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from sanic.exceptions import (
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ContentRangeError,
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HeaderNotFound,
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INTERNAL_SERVER_ERROR_HTML,
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InvalidRangeType,
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SanicException,
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TRACEBACK_LINE_HTML,
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TRACEBACK_STYLE,
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TRACEBACK_WRAPPER_HTML)
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from sanic.log import log
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from sanic.response import text, html
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class ErrorHandler:
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handlers = None
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def __init__(self):
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self.handlers = {}
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self.debug = False
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def _render_traceback_html(self, exception, request):
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exc_type, exc_value, tb = sys.exc_info()
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frames = extract_tb(tb)
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frame_html = []
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for frame in frames:
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frame_html.append(TRACEBACK_LINE_HTML.format(frame))
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return TRACEBACK_WRAPPER_HTML.format(
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style=TRACEBACK_STYLE,
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exc_name=exc_type.__name__,
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exc_value=exc_value,
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frame_html=''.join(frame_html),
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uri=request.url)
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def add(self, exception, handler):
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self.handlers[exception] = handler
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def response(self, request, exception):
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"""Fetches and executes an exception handler and returns a response
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object
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:param request: Request
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:param exception: Exception to handle
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:return: Response object
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"""
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handler = self.handlers.get(type(exception), self.default)
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try:
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response = handler(request=request, exception=exception)
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except Exception:
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self.log(format_exc())
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if self.debug:
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url = getattr(request, 'url', 'unknown')
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response_message = (
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'Exception raised in exception handler "{}" '
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'for uri: "{}"\n{}').format(
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handler.__name__, url, format_exc())
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log.error(response_message)
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return text(response_message, 500)
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else:
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return text('An error occurred while handling an error', 500)
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return response
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def log(self, message, level='error'):
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"""
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Override this method in an ErrorHandler subclass to prevent
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logging exceptions.
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"""
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getattr(log, level)(message)
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def default(self, request, exception):
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self.log(format_exc())
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if issubclass(type(exception), SanicException):
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return text(
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'Error: {}'.format(exception),
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status=getattr(exception, 'status_code', 500),
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headers=getattr(exception, 'headers', dict())
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)
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elif self.debug:
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html_output = self._render_traceback_html(exception, request)
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response_message = (
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'Exception occurred while handling uri: "{}"\n{}'.format(
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request.url, format_exc()))
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log.error(response_message)
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return html(html_output, status=500)
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else:
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return html(INTERNAL_SERVER_ERROR_HTML, status=500)
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class ContentRangeHandler:
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"""Class responsible for parsing request header"""
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__slots__ = ('start', 'end', 'size', 'total', 'headers')
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def __init__(self, request, stats):
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self.total = stats.st_size
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_range = request.headers.get('Range')
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if _range is None:
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raise HeaderNotFound('Range Header Not Found')
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unit, _, value = tuple(map(str.strip, _range.partition('=')))
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if unit != 'bytes':
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raise InvalidRangeType(
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'%s is not a valid Range Type' % (unit,), self)
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start_b, _, end_b = tuple(map(str.strip, value.partition('-')))
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try:
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self.start = int(start_b) if start_b else None
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except ValueError:
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raise ContentRangeError(
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'\'%s\' is invalid for Content Range' % (start_b,), self)
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try:
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self.end = int(end_b) if end_b else None
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except ValueError:
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raise ContentRangeError(
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'\'%s\' is invalid for Content Range' % (end_b,), self)
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if self.end is None:
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if self.start is None:
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raise ContentRangeError(
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'Invalid for Content Range parameters', self)
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else:
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# this case represents `Content-Range: bytes 5-`
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self.end = self.total
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else:
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if self.start is None:
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# this case represents `Content-Range: bytes -5`
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self.start = self.total - self.end
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self.end = self.total
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if self.start >= self.end:
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raise ContentRangeError(
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'Invalid for Content Range parameters', self)
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self.size = self.end - self.start
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self.headers = {
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'Content-Range': "bytes %s-%s/%s" % (
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self.start, self.end, self.total)}
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def __bool__(self):
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return self.size > 0
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