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Direktori : /opt/alt/python37/lib/python3.7/site-packages/paste/evalexception/ |
Current File : //opt/alt/python37/lib/python3.7/site-packages/paste/evalexception/middleware.py |
# (c) 2005 Ian Bicking and contributors; written for Paste (http://pythonpaste.org) # Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php """ Exception-catching middleware that allows interactive debugging. This middleware catches all unexpected exceptions. A normal traceback, like produced by ``paste.exceptions.errormiddleware.ErrorMiddleware`` is given, plus controls to see local variables and evaluate expressions in a local context. This can only be used in single-process environments, because subsequent requests must go back to the same process that the exception originally occurred in. Threaded or non-concurrent environments both work. This shouldn't be used in production in any way. That would just be silly. If calling from an XMLHttpRequest call, if the GET variable ``_`` is given then it will make the response more compact (and less Javascripty), since if you use innerHTML it'll kill your browser. You can look for the header X-Debug-URL in your 500 responses if you want to see the full debuggable traceback. Also, this URL is printed to ``wsgi.errors``, so you can open it up in another browser window. """ import sys import os import cgi import traceback from cStringIO import StringIO import pprint import itertools import time import re from paste.exceptions import errormiddleware, formatter, collector from paste import wsgilib from paste import urlparser from paste import httpexceptions from paste import registry from paste import request from paste import response import evalcontext limit = 200 def html_quote(v): """ Escape HTML characters, plus translate None to '' """ if v is None: return '' return cgi.escape(str(v), 1) def preserve_whitespace(v, quote=True): """ Quote a value for HTML, preserving whitespace (translating newlines to ``<br>`` and multiple spaces to use `` ``). If ``quote`` is true, then the value will be HTML quoted first. """ if quote: v = html_quote(v) v = v.replace('\n', '<br>\n') v = re.sub(r'()( +)', _repl_nbsp, v) v = re.sub(r'(\n)( +)', _repl_nbsp, v) v = re.sub(r'^()( +)', _repl_nbsp, v) return '<code>%s</code>' % v def _repl_nbsp(match): if len(match.group(2)) == 1: return ' ' return match.group(1) + ' ' * (len(match.group(2))-1) + ' ' def simplecatcher(application): """ A simple middleware that catches errors and turns them into simple tracebacks. """ def simplecatcher_app(environ, start_response): try: return application(environ, start_response) except: out = StringIO() traceback.print_exc(file=out) start_response('500 Server Error', [('content-type', 'text/html')], sys.exc_info()) res = out.getvalue() return ['<h3>Error</h3><pre>%s</pre>' % html_quote(res)] return simplecatcher_app def wsgiapp(): """ Turns a function or method into a WSGI application. """ def decorator(func): def wsgiapp_wrapper(*args): # we get 3 args when this is a method, two when it is # a function :( if len(args) == 3: environ = args[1] start_response = args[2] args = [args[0]] else: environ, start_response = args args = [] def application(environ, start_response): form = wsgilib.parse_formvars(environ, include_get_vars=True) headers = response.HeaderDict( {'content-type': 'text/html', 'status': '200 OK'}) form['environ'] = environ form['headers'] = headers res = func(*args, **form.mixed()) status = headers.pop('status') start_response(status, headers.headeritems()) return [res] app = httpexceptions.make_middleware(application) app = simplecatcher(app) return app(environ, start_response) wsgiapp_wrapper.exposed = True return wsgiapp_wrapper return decorator def get_debug_info(func): """ A decorator (meant to be used under ``wsgiapp()``) that resolves the ``debugcount`` variable to a ``DebugInfo`` object (or gives an error if it can't be found). """ def debug_info_replacement(self, **form): try: if 'debugcount' not in form: raise ValueError('You must provide a debugcount parameter') debugcount = form.pop('debugcount') try: debugcount = int(debugcount) except ValueError: raise ValueError('Bad value for debugcount') if debugcount not in self.debug_infos: raise ValueError( 'Debug %s no longer found (maybe it has expired?)' % debugcount) debug_info = self.debug_infos[debugcount] return func(self, debug_info=debug_info, **form) except ValueError, e: form['headers']['status'] = '500 Server Error' return '<html>There was an error: %s</html>' % html_quote(e) return debug_info_replacement debug_counter = itertools.count(int(time.time())) def get_debug_count(environ): """ Return the unique debug count for the current request """ if 'paste.evalexception.debug_count' in environ: return environ['paste.evalexception.debug_count'] else: environ['paste.evalexception.debug_count'] = next = debug_counter.next() return next class EvalException(object): def __init__(self, application, global_conf=None, xmlhttp_key=None): self.application = application self.debug_infos = {} if xmlhttp_key is None: if global_conf is None: xmlhttp_key = '_' else: xmlhttp_key = global_conf.get('xmlhttp_key', '_') self.xmlhttp_key = xmlhttp_key def __call__(self, environ, start_response): assert not environ['wsgi.multiprocess'], ( "The EvalException middleware is not usable in a " "multi-process environment") environ['paste.evalexception'] = self if environ.get('PATH_INFO', '').startswith('/_debug/'): return self.debug(environ, start_response) else: return self.respond(environ, start_response) def debug(self, environ, start_response): assert request.path_info_pop(environ) == '_debug' next_part = request.path_info_pop(environ) method = getattr(self, next_part, None) if not method: exc = httpexceptions.HTTPNotFound( '%r not found when parsing %r' % (next_part, wsgilib.construct_url(environ))) return exc.wsgi_application(environ, start_response) if not getattr(method, 'exposed', False): exc = httpexceptions.HTTPForbidden( '%r not allowed' % next_part) return exc.wsgi_application(environ, start_response) return method(environ, start_response) def media(self, environ, start_response): """ Static path where images and other files live """ app = urlparser.StaticURLParser( os.path.join(os.path.dirname(__file__), 'media')) return app(environ, start_response) media.exposed = True def mochikit(self, environ, start_response): """ Static path where MochiKit lives """ app = urlparser.StaticURLParser( os.path.join(os.path.dirname(__file__), 'mochikit')) return app(environ, start_response) mochikit.exposed = True def summary(self, environ, start_response): """ Returns a JSON-format summary of all the cached exception reports """ start_response('200 OK', [('Content-type', 'text/x-json')]) data = []; items = self.debug_infos.values() items.sort(lambda a, b: cmp(a.created, b.created)) data = [item.json() for item in items] return [repr(data)] summary.exposed = True def view(self, environ, start_response): """ View old exception reports """ id = int(request.path_info_pop(environ)) if id not in self.debug_infos: start_response( '500 Server Error', [('Content-type', 'text/html')]) return [ "Traceback by id %s does not exist (maybe " "the server has been restarted?)" % id] debug_info = self.debug_infos[id] return debug_info.wsgi_application(environ, start_response) view.exposed = True def make_view_url(self, environ, base_path, count): return base_path + '/_debug/view/%s' % count #@wsgiapp() #@get_debug_info def show_frame(self, tbid, debug_info, **kw): frame = debug_info.frame(int(tbid)) vars = frame.tb_frame.f_locals if vars: registry.restorer.restoration_begin(debug_info.counter) local_vars = make_table(vars) registry.restorer.restoration_end() else: local_vars = 'No local vars' return input_form(tbid, debug_info) + local_vars show_frame = wsgiapp()(get_debug_info(show_frame)) #@wsgiapp() #@get_debug_info def exec_input(self, tbid, debug_info, input, **kw): if not input.strip(): return '' input = input.rstrip() + '\n' frame = debug_info.frame(int(tbid)) vars = frame.tb_frame.f_locals glob_vars = frame.tb_frame.f_globals context = evalcontext.EvalContext(vars, glob_vars) registry.restorer.restoration_begin(debug_info.counter) output = context.exec_expr(input) registry.restorer.restoration_end() input_html = formatter.str2html(input) return ('<code style="color: #060">>>></code> ' '<code>%s</code><br>\n%s' % (preserve_whitespace(input_html, quote=False), preserve_whitespace(output))) exec_input = wsgiapp()(get_debug_info(exec_input)) def respond(self, environ, start_response): if environ.get('paste.throw_errors'): return self.application(environ, start_response) base_path = request.construct_url(environ, with_path_info=False, with_query_string=False) environ['paste.throw_errors'] = True started = [] def detect_start_response(status, headers, exc_info=None): try: return start_response(status, headers, exc_info) except: raise else: started.append(True) try: __traceback_supplement__ = errormiddleware.Supplement, self, environ app_iter = self.application(environ, detect_start_response) try: return_iter = list(app_iter) return return_iter finally: if hasattr(app_iter, 'close'): app_iter.close() except: exc_info = sys.exc_info() for expected in environ.get('paste.expected_exceptions', []): if isinstance(exc_info[1], expected): raise # Tell the Registry to save its StackedObjectProxies current state # for later restoration registry.restorer.save_registry_state(environ) count = get_debug_count(environ) view_uri = self.make_view_url(environ, base_path, count) if not started: headers = [('content-type', 'text/html')] headers.append(('X-Debug-URL', view_uri)) start_response('500 Internal Server Error', headers, exc_info) environ['wsgi.errors'].write('Debug at: %s\n' % view_uri) exc_data = collector.collect_exception(*exc_info) debug_info = DebugInfo(count, exc_info, exc_data, base_path, environ, view_uri) assert count not in self.debug_infos self.debug_infos[count] = debug_info if self.xmlhttp_key: get_vars = wsgilib.parse_querystring(environ) if dict(get_vars).get(self.xmlhttp_key): exc_data = collector.collect_exception(*exc_info) html = formatter.format_html( exc_data, include_hidden_frames=False, include_reusable=False, show_extra_data=False) return [html] # @@: it would be nice to deal with bad content types here return debug_info.content() def exception_handler(self, exc_info, environ): simple_html_error = False if self.xmlhttp_key: get_vars = wsgilib.parse_querystring(environ) if dict(get_vars).get(self.xmlhttp_key): simple_html_error = True return errormiddleware.handle_exception( exc_info, environ['wsgi.errors'], html=True, debug_mode=True, simple_html_error=simple_html_error) class DebugInfo(object): def __init__(self, counter, exc_info, exc_data, base_path, environ, view_uri): self.counter = counter self.exc_data = exc_data self.base_path = base_path self.environ = environ self.view_uri = view_uri self.created = time.time() self.exc_type, self.exc_value, self.tb = exc_info __exception_formatter__ = 1 self.frames = [] n = 0 tb = self.tb while tb is not None and (limit is None or n < limit): if tb.tb_frame.f_locals.get('__exception_formatter__'): # Stop recursion. @@: should make a fake ExceptionFrame break self.frames.append(tb) tb = tb.tb_next n += 1 def json(self): """Return the JSON-able representation of this object""" return { 'uri': self.view_uri, 'created': time.strftime('%c', time.gmtime(self.created)), 'created_timestamp': self.created, 'exception_type': str(self.exc_type), 'exception': str(self.exc_value), } def frame(self, tbid): for frame in self.frames: if id(frame) == tbid: return frame else: raise ValueError, ( "No frame by id %s found from %r" % (tbid, self.frames)) def wsgi_application(self, environ, start_response): start_response('200 OK', [('content-type', 'text/html')]) return self.content() def content(self): html = format_eval_html(self.exc_data, self.base_path, self.counter) head_html = (formatter.error_css + formatter.hide_display_js) head_html += self.eval_javascript() repost_button = make_repost_button(self.environ) page = error_template % { 'repost_button': repost_button or '', 'head_html': head_html, 'body': html} return [page] def eval_javascript(self): base_path = self.base_path + '/_debug' return ( '<script type="text/javascript" src="%s/media/MochiKit.packed.js">' '</script>\n' '<script type="text/javascript" src="%s/media/debug.js">' '</script>\n' '<script type="text/javascript">\n' 'debug_base = %r;\n' 'debug_count = %r;\n' '</script>\n' % (base_path, base_path, base_path, self.counter)) class EvalHTMLFormatter(formatter.HTMLFormatter): def __init__(self, base_path, counter, **kw): super(EvalHTMLFormatter, self).__init__(**kw) self.base_path = base_path self.counter = counter def format_source_line(self, filename, frame): line = formatter.HTMLFormatter.format_source_line( self, filename, frame) return (line + ' <a href="#" class="switch_source" ' 'tbid="%s" onClick="return showFrame(this)"> ' '<img src="%s/_debug/media/plus.jpg" border=0 width=9 ' 'height=9> </a>' % (frame.tbid, self.base_path)) def make_table(items): if isinstance(items, dict): items = items.items() items.sort() rows = [] i = 0 for name, value in items: i += 1 out = StringIO() try: pprint.pprint(value, out) except Exception, e: print >> out, 'Error: %s' % e value = html_quote(out.getvalue()) if len(value) > 100: # @@: This can actually break the HTML :( # should I truncate before quoting? orig_value = value value = value[:100] value += '<a class="switch_source" style="background-color: #999" href="#" onclick="return expandLong(this)">...</a>' value += '<span style="display: none">%s</span>' % orig_value[100:] value = formatter.make_wrappable(value) if i % 2: attr = ' class="even"' else: attr = ' class="odd"' rows.append('<tr%s style="vertical-align: top;"><td>' '<b>%s</b></td><td style="overflow: auto">%s<td></tr>' % (attr, html_quote(name), preserve_whitespace(value, quote=False))) return '<table>%s</table>' % ( '\n'.join(rows)) def format_eval_html(exc_data, base_path, counter): short_formatter = EvalHTMLFormatter( base_path=base_path, counter=counter, include_reusable=False) short_er = short_formatter.format_collected_data(exc_data) long_formatter = EvalHTMLFormatter( base_path=base_path, counter=counter, show_hidden_frames=True, show_extra_data=False, include_reusable=False) long_er = long_formatter.format_collected_data(exc_data) text_er = formatter.format_text(exc_data, show_hidden_frames=True) if short_formatter.filter_frames(exc_data.frames) != \ long_formatter.filter_frames(exc_data.frames): # Only display the full traceback when it differs from the # short version full_traceback_html = """ <br> <script type="text/javascript"> show_button('full_traceback', 'full traceback') </script> <div id="full_traceback" class="hidden-data"> %s </div> """ % long_er else: full_traceback_html = '' return """ %s %s <br> <script type="text/javascript"> show_button('text_version', 'text version') </script> <div id="text_version" class="hidden-data"> <textarea style="width: 100%%" rows=10 cols=60>%s</textarea> </div> """ % (short_er, full_traceback_html, cgi.escape(text_er)) def make_repost_button(environ): url = request.construct_url(environ) if environ['REQUEST_METHOD'] == 'GET': return ('<button onclick="window.location.href=%r">' 'Re-GET Page</button><br>' % url) else: # @@: I'd like to reconstruct this, but I can't because # the POST body is probably lost at this point, and # I can't get it back :( return None # @@: Use or lose the following code block """ fields = [] for name, value in wsgilib.parse_formvars( environ, include_get_vars=False).items(): if hasattr(value, 'filename'): # @@: Arg, we'll just submit the body, and leave out # the filename :( value = value.value fields.append( '<input type="hidden" name="%s" value="%s">' % (html_quote(name), html_quote(value))) return ''' <form action="%s" method="POST"> %s <input type="submit" value="Re-POST Page"> </form>''' % (url, '\n'.join(fields)) """ def input_form(tbid, debug_info): return ''' <form action="#" method="POST" onsubmit="return submitInput($(\'submit_%(tbid)s\'), %(tbid)s)"> <div id="exec-output-%(tbid)s" style="width: 95%%; padding: 5px; margin: 5px; border: 2px solid #000; display: none"></div> <input type="text" name="input" id="debug_input_%(tbid)s" style="width: 100%%" autocomplete="off" onkeypress="upArrow(this, event)"><br> <input type="submit" value="Execute" name="submitbutton" onclick="return submitInput(this, %(tbid)s)" id="submit_%(tbid)s" input-from="debug_input_%(tbid)s" output-to="exec-output-%(tbid)s"> <input type="submit" value="Expand" onclick="return expandInput(this)"> </form> ''' % {'tbid': tbid} error_template = ''' <html> <head> <title>Server Error</title> %(head_html)s </head> <body> <div id="error-area" style="display: none; background-color: #600; color: #fff; border: 2px solid black"> <div id="error-container"></div> <button onclick="return clearError()">clear this</button> </div> %(repost_button)s %(body)s </body> </html> ''' def make_eval_exception(app, global_conf, xmlhttp_key=None): """ Wraps the application in an interactive debugger. This debugger is a major security hole, and should only be used during development. xmlhttp_key is a string that, if present in QUERY_STRING, indicates that the request is an XMLHttp request, and the Javascript/interactive debugger should not be returned. (If you try to put the debugger somewhere with innerHTML, you will often crash the browser) """ if xmlhttp_key is None: xmlhttp_key = global_conf.get('xmlhttp_key', '_') return EvalException(app, xmlhttp_key=xmlhttp_key)