Source code for google.appengine.ext.appstats.formatting

#!/usr/bin/env python
#
# Copyright 2007 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#




"""A fast but lossy, totally generic object formatter."""



import os
import types

from google.net.proto import ProtocolBuffer
try:
  from google.appengine._internal.proto1 import message
except ImportError:
  message = None


EASY_TYPES = (type(None), int, long, float, bool)
META_TYPES = (type, types.ClassType)
STRING_TYPES = (str, unicode)
CONTAINER_TYPES = {tuple: ('(', ')'),
                   list: ('[', ']'),
                   dict: ('{', '}'),
                   }
BUILTIN_TYPES = EASY_TYPES + STRING_TYPES + tuple(CONTAINER_TYPES)
INSTANCE_TYPE = types.InstanceType


[docs]def format_value(val, limit=100, level=10): """Wrapper around _format_value().""" return _format_value(val, limit, level)
def _format_value(val, limit, level, len=len, repr=repr): """Format an arbitrary value as a compact string. This is a variant on Python's built-in repr() function, also borrowing some ideas from the repr.py standard library module, but tuned for speed even in extreme cases (like very large longs or very long strings) and safety (it never invokes user code). For structured data types like lists and objects it calls itself recursively; recursion is strictly limited by level. Python's basic types (numbers, strings, lists, tuples, dicts, bool, and None) are represented using their familiar Python notations. Objects are represented as ClassName<attr1=val1, attr2=val2, ...>. Portions omitted due to the various limits are represented using three dots ('...'). Args: val: An arbitrary value. limit: Limit on the output length. level: Recursion level countdown. len, repr: Not arguments; for optimization. Returns: A str instance. """ if level <= 0: return '...' typ = type(val) if typ in EASY_TYPES: if typ is float: rep = str(val) elif typ is long: if val >= 10L**99: return '...L' elif val <= -10L**98: return '-...L' else: rep = repr(val) else: rep = repr(val) if typ is long and len(rep) > limit: n1 = (limit - 3) // 2 n2 = (limit - 3) - n1 rep = rep[:n1] + '...' + rep[-n2:] return rep if typ in META_TYPES: return val.__name__ if typ in STRING_TYPES: n1 = (limit - 3) // 2 if n1 < 1: n1 = 1 n2 = (limit - 3) - n1 if n2 < 1: n2 = 1 if len(val) > limit: rep = repr(val[:n1] + val[-n2:]) else: rep = repr(val) if len(rep) <= limit: return rep return rep[:n1] + '...' + rep[-n2:] if typ is types.MethodType: if val.im_self is None: fmt = '<unbound method %s of %s>' else: fmt = '<method %s of %s<>>' if val.im_class is not None: return fmt % (val.__name__, val.im_class.__name__) else: return fmt % (val.__name__, '?') if typ is types.FunctionType: nam = val.__name__ if nam == '<lambda>': return nam else: return '<function %s>' % val.__name__ if typ is types.BuiltinFunctionType: if val.__self__ is not None: return '<built-in method %s of %s<>>' % (val.__name__, type(val.__self__).__name__) else: return '<built-in function %s>' % val.__name__ if typ is types.ModuleType: if hasattr(val, '__file__'): return '<module %s>' % val.__name__ else: return '<built-in module %s>' % val.__name__ if typ is types.CodeType: return '<code object %s>' % val.co_name if isinstance(val, ProtocolBuffer.ProtocolMessage): buf = [val.__class__.__name__, '<'] limit -= len(buf[0]) + 2 append = buf.append first = True dct = getattr(val, '__dict__', None) if dct: for k, v in sorted(dct.items()): if k.startswith('has_') or not k.endswith('_'): continue name = k[:-1] has_method = getattr(val, 'has_' + name, None) if has_method is not None: if type(has_method) is not types.MethodType or not has_method(): continue size_method = getattr(val, name + '_size', None) if size_method is not None: if type(size_method) is not types.MethodType or not size_method(): continue if has_method is None and size_method is None: continue if first: first = False else: append(', ') limit -= len(name) + 2 if limit <= 0: append('...') break append(name) append('=') rep = _format_value(v, limit, level-1) limit -= len(rep) append(rep) append('>') return ''.join(buf) dct = getattr(val, '__dict__', None) if type(dct) is dict: if typ is INSTANCE_TYPE: typ = val.__class__ typnam = typ.__name__ priv = '_' + typnam + '__' buffer = [typnam, '<'] limit -= len(buffer[0]) + 2 if len(dct) <= limit//4: names = sorted(dct) else: names = list(dct) append = buffer.append first = True if issubclass(typ, BUILTIN_TYPES): for builtin_typ in BUILTIN_TYPES: if issubclass(typ, builtin_typ): try: val = builtin_typ(val) assert type(val) is builtin_typ except Exception: break else: append(_format_value(val, limit, level-1)) first = False break for nam in names: if not isinstance(nam, basestring): continue if first: first = False else: append(', ') pnam = nam if pnam.startswith(priv): pnam = pnam[len(priv)-2:] limit -= len(pnam) + 2 if limit <= 0: append('...') break append(pnam) append('=') rep = _format_value(dct[nam], limit, level-1) limit -= len(rep) append(rep) append('>') return ''.join(buffer) how = CONTAINER_TYPES.get(typ) if how: head, tail = how buffer = [head] append = buffer.append limit -= 2 series = val isdict = typ is dict if isdict and len(val) <= limit//4: series = sorted(val) try: for elem in series: if limit <= 0: append('...') break rep = _format_value(elem, limit, level-1) limit -= len(rep) + 2 append(rep) if isdict: rep = _format_value(val[elem], limit, level-1) limit -= len(rep) append(':') append(rep) append(', ') if buffer[-1] == ', ': if tail == ')' and len(val) == 1: buffer[-1] = ',)' else: buffer[-1] = tail else: append(tail) return ''.join(buffer) except (RuntimeError, KeyError): return head + tail + ' (Container modified during iteration)' if issubclass(typ, BUILTIN_TYPES): for builtin_typ in BUILTIN_TYPES: if issubclass(typ, builtin_typ): try: val = builtin_typ(val) assert type(val) is builtin_typ except Exception: break else: typnam = typ.__name__ limit -= len(typnam) + 2 return '%s<%s>' % (typnam, _format_value(val, limit, level-1)) if message is not None and isinstance(val, message.Message): buffer = [typ.__name__, '<'] limit -= len(buffer[0]) + 2 append = buffer.append first = True fields = val.ListFields() for f, v in fields: if first: first = False else: append(', ') name = f.name limit -= len(name) + 2 if limit <= 0: append('...') break append(name) append('=') if f.label == f.LABEL_REPEATED: limit -= 2 append('[') first_sub = True for item in v: if first_sub: first_sub = False else: limit -= 2 append(', ') if limit <= 0: append('...') break rep = _format_value(item, limit, level-1) limit -= len(rep) append(rep) append(']') else: rep = _format_value(v, limit, level-1) limit -= len(rep) append(rep) append('>') return ''.join(buffer) return typ.__name__ + '<>'

Send feedback about...

App Engine standard environment for Python