raven/utils/stacks.py
"""
raven.utils.stacks
~~~~~~~~~~~~~~~~~~~~~~~~~~
:copyright: (c) 2010-2012 by the Sentry Team, see AUTHORS for more details.
:license: BSD, see LICENSE for more details.
"""
from __future__ import absolute_import, division
import inspect
import linecache
import re
import os
import sys
from raven.utils.serializer import transform
from raven.utils.compat import iteritems
_coding_re = re.compile(r'coding[:=]\s*([-\w.]+)')
def get_lines_from_file(filename, lineno, context_lines,
loader=None, module_name=None):
"""
Returns context_lines before and after lineno from file.
Returns (pre_context_lineno, pre_context, context_line, post_context).
"""
source = None
if loader is not None and hasattr(loader, "get_source"):
try:
source = loader.get_source(module_name)
except (ImportError, IOError):
# Traceback (most recent call last):
# File "/Users/dcramer/Development/django-sentry/sentry/client/handlers.py", line 31, in emit
# get_client().create_from_record(record, request=request)
# File "/Users/dcramer/Development/django-sentry/sentry/client/base.py", line 325, in create_from_record
# data['__sentry__']['frames'] = varmap(shorten, get_stack_info(stack))
# File "/Users/dcramer/Development/django-sentry/sentry/utils/stacks.py", line 112, in get_stack_info
# pre_context_lineno, pre_context, context_line, post_context = get_lines_from_file(filename, lineno, 7, loader, module_name)
# File "/Users/dcramer/Development/django-sentry/sentry/utils/stacks.py", line 24, in get_lines_from_file
# source = loader.get_source(module_name)
# File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/pkgutil.py", line 287, in get_source
# fullname = self._fix_name(fullname)
# File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/pkgutil.py", line 262, in _fix_name
# "module %s" % (self.fullname, fullname))
# ImportError: Loader for module cProfile cannot handle module __main__
source = None
if source is not None:
source = source.splitlines()
if source is None:
try:
source = linecache.getlines(filename)
except (OSError, IOError):
return None, None, None
if not source:
return None, None, None
lower_bound = max(0, lineno - context_lines)
upper_bound = min(lineno + 1 + context_lines, len(source))
try:
pre_context = [
line.strip('\r\n')
for line in source[lower_bound:lineno]
]
context_line = source[lineno].strip('\r\n')
post_context = [
line.strip('\r\n')
for line in source[(lineno + 1):upper_bound]
]
except IndexError:
# the file may have changed since it was loaded into memory
return None, None, None
return (
slim_string(pre_context),
slim_string(context_line),
slim_string(post_context)
)
def _getitem_from_frame(f_locals, key, default=None):
"""
f_locals is not guaranteed to have .get(), but it will always
support __getitem__. Even if it doesn't, we return ``default``.
"""
try:
return f_locals[key]
except Exception:
return default
def to_dict(dictish):
"""
Given something that closely resembles a dictionary, we attempt
to coerce it into a propery dictionary.
"""
if hasattr(dictish, 'iterkeys'):
m = dictish.iterkeys
elif hasattr(dictish, 'keys'):
m = dictish.keys
else:
raise ValueError(dictish)
return dict((k, dictish[k]) for k in m())
def iter_traceback_frames(tb):
"""
Given a traceback object, it will iterate over all
frames that do not contain the ``__traceback_hide__``
local variable.
"""
# Some versions of celery have hacked traceback objects that might
# miss tb_frame.
while tb and hasattr(tb, 'tb_frame'):
# support for __traceback_hide__ which is used by a few libraries
# to hide internal frames.
f_locals = getattr(tb.tb_frame, 'f_locals', {})
if not _getitem_from_frame(f_locals, '__traceback_hide__'):
yield tb.tb_frame, getattr(tb, 'tb_lineno', None)
tb = tb.tb_next
def iter_stack_frames(frames=None):
"""
Given an optional list of frames (defaults to current stack),
iterates over all frames that do not contain the ``__traceback_hide__``
local variable.
"""
if not frames:
frames = inspect.stack()[1:]
for frame, lineno in ((f[0], f[2]) for f in reversed(frames)):
f_locals = getattr(frame, 'f_locals', {})
if not _getitem_from_frame(f_locals, '__traceback_hide__'):
yield frame, lineno
def get_frame_locals(frame, transformer=transform, max_var_size=4096):
f_locals = getattr(frame, 'f_locals', None)
if not f_locals:
return None
if not isinstance(f_locals, dict):
# XXX: Genshi (and maybe others) have broken implementations of
# f_locals that are not actually dictionaries
try:
f_locals = to_dict(f_locals)
except Exception:
return None
f_vars = {}
f_size = 0
for k, v in iteritems(f_locals):
v = transformer(v)
v_size = len(repr(v))
if v_size + f_size < max_var_size:
f_vars[k] = v
f_size += v_size
return f_vars
def slim_frame_data(frames, frame_allowance=25):
"""
Removes various excess metadata from middle frames which go beyond
``frame_allowance``.
Returns ``frames``.
"""
frames_len = 0
app_frames = []
system_frames = []
for frame in frames:
frames_len += 1
if frame.get('in_app'):
app_frames.append(frame)
else:
system_frames.append(frame)
if frames_len <= frame_allowance:
return frames
remaining = frames_len - frame_allowance
app_count = len(app_frames)
system_allowance = max(frame_allowance - app_count, 0)
if system_allowance:
half_max = int(system_allowance / 2)
# prioritize trimming system frames
for frame in system_frames[half_max:-half_max]:
frame.pop('vars', None)
frame.pop('pre_context', None)
frame.pop('post_context', None)
remaining -= 1
else:
for frame in system_frames:
frame.pop('vars', None)
frame.pop('pre_context', None)
frame.pop('post_context', None)
remaining -= 1
if remaining:
app_allowance = app_count - remaining
half_max = int(app_allowance / 2)
for frame in app_frames[half_max:-half_max]:
frame.pop('vars', None)
frame.pop('pre_context', None)
frame.pop('post_context', None)
return frames
def slim_string(value, length=512):
if not value:
return value
if len(value) > length:
return value[:length - 3] + '...'
return value[:length]
def get_stack_info(frames, transformer=transform, capture_locals=True,
frame_allowance=25):
"""
Given a list of frames, returns a list of stack information
dictionary objects that are JSON-ready.
We have to be careful here as certain implementations of the
_Frame class do not contain the necessary data to lookup all
of the information we want.
"""
__traceback_hide__ = True # NOQA
result = []
for frame_info in frames:
# Old, terrible API
if isinstance(frame_info, (list, tuple)):
frame, lineno = frame_info
else:
frame = frame_info
lineno = frame_info.f_lineno
# Support hidden frames
f_locals = getattr(frame, 'f_locals', {})
if _getitem_from_frame(f_locals, '__traceback_hide__'):
continue
f_globals = getattr(frame, 'f_globals', {})
f_code = getattr(frame, 'f_code', None)
if f_code:
abs_path = frame.f_code.co_filename
function = frame.f_code.co_name
else:
abs_path = None
function = None
loader = _getitem_from_frame(f_globals, '__loader__')
module_name = _getitem_from_frame(f_globals, '__name__')
if lineno:
lineno -= 1
if lineno is not None and abs_path:
pre_context, context_line, post_context = \
get_lines_from_file(abs_path, lineno, 5, loader, module_name)
else:
pre_context, context_line, post_context = None, None, None
# Try to pull a relative file path
# This changes /foo/site-packages/baz/bar.py into baz/bar.py
try:
base_filename = sys.modules[module_name.split('.', 1)[0]].__file__
filename = abs_path.split(
base_filename.rsplit(os.sep, 2)[0], 1)[-1].lstrip(os.sep)
except Exception:
filename = abs_path
if not filename:
filename = abs_path
frame_result = {
'abs_path': abs_path,
'filename': filename,
'module': module_name or None,
'function': function or '<unknown>',
'lineno': lineno + 1,
}
if capture_locals:
f_vars = get_frame_locals(frame, transformer=transformer)
if f_vars:
frame_result['vars'] = f_vars
if context_line is not None:
frame_result.update({
'pre_context': pre_context,
'context_line': context_line,
'post_context': post_context,
})
result.append(frame_result)
stackinfo = {
'frames': slim_frame_data(result, frame_allowance=frame_allowance),
}
return stackinfo