# config.py
# Copyright (C) 2008, 2009 Michael Trier (mtrier@gmail.com) and contributors
#
# This module is part of GitPython and is released under
# the BSD License: http://www.opensource.org/licenses/bsd-license.php
"""Module containing module parser implementation able to properly read and write
configuration files"""
import abc
from functools import wraps
import inspect
import logging
import os
import re
from collections import OrderedDict
from git.compat import (
string_types,
FileType,
defenc,
force_text,
with_metaclass,
PY3
)
from git.util import LockFile
import os.path as osp
try:
import ConfigParser as cp
except ImportError:
# PY3
import configparser as cp
__all__ = ('GitConfigParser', 'SectionConstraint')
log = logging.getLogger('git.config')
log.addHandler(logging.NullHandler())
class MetaParserBuilder(abc.ABCMeta):
"""Utlity class wrapping base-class methods into decorators that assure read-only properties"""
def __new__(cls, name, bases, clsdict):
"""
Equip all base-class methods with a needs_values decorator, and all non-const methods
with a set_dirty_and_flush_changes decorator in addition to that."""
kmm = '_mutating_methods_'
if kmm in clsdict:
mutating_methods = clsdict[kmm]
for base in bases:
methods = (t for t in inspect.getmembers(base, inspect.isroutine) if not t[0].startswith("_"))
for name, method in methods:
if name in clsdict:
continue
method_with_values = needs_values(method)
if name in mutating_methods:
method_with_values = set_dirty_and_flush_changes(method_with_values)
# END mutating methods handling
clsdict[name] = method_with_values
# END for each name/method pair
# END for each base
# END if mutating methods configuration is set
new_type = super(MetaParserBuilder, cls).__new__(cls, name, bases, clsdict)
return new_type
def needs_values(func):
"""Returns method assuring we read values (on demand) before we try to access them"""
@wraps(func)
def assure_data_present(self, *args, **kwargs):
self.read()
return func(self, *args, **kwargs)
# END wrapper method
return assure_data_present
def set_dirty_and_flush_changes(non_const_func):
"""Return method that checks whether given non constant function may be called.
If so, the instance will be set dirty.
Additionally, we flush the changes right to disk"""
def flush_changes(self, *args, **kwargs):
rval = non_const_func(self, *args, **kwargs)
self._dirty = True
self.write()
return rval
# END wrapper method
flush_changes.__name__ = non_const_func.__name__
return flush_changes
class SectionConstraint(object):
"""Constrains a ConfigParser to only option commands which are constrained to
always use the section we have been initialized with.
It supports all ConfigParser methods that operate on an option.
:note:
If used as a context manager, will release the wrapped ConfigParser."""
__slots__ = ("_config", "_section_name")
_valid_attrs_ = ("get_value", "set_value", "get", "set", "getint", "getfloat", "getboolean", "has_option",
"remove_section", "remove_option", "options")
def __init__(self, config, section):
self._config = config
self._section_name = section
def __del__(self):
# Yes, for some reason, we have to call it explicitly for it to work in PY3 !
# Apparently __del__ doesn't get call anymore if refcount becomes 0
# Ridiculous ... .
self._config.release()
def __getattr__(self, attr):
if attr in self._valid_attrs_:
return lambda *args, **kwargs: self._call_config(attr, *args, **kwargs)
return super(SectionConstraint, self).__getattribute__(attr)
def _call_config(self, method, *args, **kwargs):
"""Call the configuration at the given method which must take a section name
as first argument"""
return getattr(self._config, method)(self._section_name, *args, **kwargs)
@property
def config(self):
"""return: Configparser instance we constrain"""
return self._config
def release(self):
"""Equivalent to GitConfigParser.release(), which is called on our underlying parser instance"""
return self._config.release()
def __enter__(self):
self._config.__enter__()
return self
def __exit__(self, exception_type, exception_value, traceback):
self._config.__exit__(exception_type, exception_value, traceback)
class GitConfigParser(with_metaclass(MetaParserBuilder, cp.RawConfigParser, object)):
"""Implements specifics required to read git style configuration files.
This variation behaves much like the git.config command such that the configuration
will be read on demand based on the filepath given during initialization.
The changes will automatically be written once the instance goes out of scope, but
can be triggered manually as well.
The configuration file will be locked if you intend to change values preventing other
instances to write concurrently.
:note:
The config is case-sensitive even when queried, hence section and option names
must match perfectly.
If used as a context manager, will release the locked file."""
#{ Configuration
# The lock type determines the type of lock to use in new configuration readers.
# They must be compatible to the LockFile interface.
# A suitable alternative would be the BlockingLockFile
t_lock = LockFile
re_comment = re.compile(r'^\s*[#;]')
#} END configuration
optvalueonly_source = r'\s*(?P<option>[^:=\s][^:=]*)'
OPTVALUEONLY = re.compile(optvalueonly_source)
OPTCRE = re.compile(optvalueonly_source + r'\s*(?P<vi>[:=])\s*' + r'(?P<value>.*)$')
del optvalueonly_source
# list of RawConfigParser methods able to change the instance
_mutating_methods_ = ("add_section", "remove_section", "remove_option", "set")
def __init__(self, file_or_files, read_only=True, merge_includes=True):
"""Initialize a configuration reader to read the given file_or_files and to
possibly allow changes to it by setting read_only False
:param file_or_files:
A single file path or file objects or multiple of these
:param read_only:
If True, the ConfigParser may only read the data , but not change it.
If False, only a single file path or file object may be given. We will write back the changes
when they happen, or when the ConfigParser is released. This will not happen if other
configuration files have been included
:param merge_includes: if True, we will read files mentioned in [include] sections and merge their
contents into ours. This makes it impossible to write back an individual configuration file.
Thus, if you want to modify a single configuration file, turn this off to leave the original
dataset unaltered when reading it."""
cp.RawConfigParser.__init__(self, dict_type=OrderedDict)
# Used in python 3, needs to stay in sync with sections for underlying implementation to work
if not hasattr(self, '_proxies'):
self._proxies = self._dict()
self._file_or_files = file_or_files
self._read_only = read_only
self._dirty = False
self._is_initialized = False
self._merge_includes = merge_includes
self._lock = None
self._acquire_lock()
def _acquire_lock(self):
if not self._read_only:
if not self._lock:
if isinstance(self._file_or_files, (tuple, list)):
raise ValueError(
"Write-ConfigParsers can operate on a single file only, multiple files have been passed")
# END single file check
file_or_files = self._file_or_files
if not isinstance(self._file_or_files, string_types):
file_or_files = self._file_or_files.name
# END get filename from handle/stream
# initialize lock base - we want to write
self._lock = self.t_lock(file_or_files)
# END lock check
self._lock._obtain_lock()
# END read-only check
def __del__(self):
"""Write pending changes if required and release locks"""
# NOTE: only consistent in PY2
self.release()
def __enter__(self):
self._acquire_lock()
return self
def __exit__(self, exception_type, exception_value, traceback):
self.release()
def release(self):
"""Flush changes and release the configuration write lock. This instance must not be used anymore afterwards.
In Python 3, it's required to explicitly release locks and flush changes, as __del__ is not called
deterministically anymore."""
# checking for the lock here makes sure we do not raise during write()
# in case an invalid parser was created who could not get a lock
if self.read_only or (self._lock and not self._lock._has_lock()):
return
try:
try:
self.write()
except IOError:
log.error("Exception during destruction of GitConfigParser", exc_info=True)
except ReferenceError:
# This happens in PY3 ... and usually means that some state cannot be written
# as the sections dict cannot be iterated
# Usually when shutting down the interpreter, don'y know how to fix this
pass
finally:
self._lock._release_lock()
def optionxform(self, optionstr):
"""Do not transform options in any way when writing"""
return optionstr
def _read(self, fp, fpname):
"""A direct copy of the py2.4 version of the super class's _read method
to assure it uses ordered dicts. Had to change one line to make it work.
Future versions have this fixed, but in fact its quite embarrassing for the
guys not to have done it right in the first place !
Removed big comments to make it more compact.
Made sure it ignores initial whitespace as git uses tabs"""
cursect = None # None, or a dictionary
optname = None
lineno = 0
is_multi_line = False
e = None # None, or an exception
def string_decode(v):
if v[-1] == '\\':
v = v[:-1]
# end cut trailing escapes to prevent decode error
if PY3:
return v.encode(defenc).decode('unicode_escape')
else:
return v.decode('string_escape')
# end
# end
while True:
# we assume to read binary !
line = fp.readline().decode(defenc)
if not line:
break
lineno = lineno + 1
# comment or blank line?
if line.strip() == '' or self.re_comment.match(line):
continue
if line.split(None, 1)[0].lower() == 'rem' and line[0] in "rR":
# no leading whitespace
continue
# is it a section header?
mo = self.SECTCRE.match(line.strip())
if not is_multi_line and mo:
sectname = mo.group('header').strip()
if sectname in self._sections:
cursect = self._sections[sectname]
elif sectname == cp.DEFAULTSECT:
cursect = self._defaults
else:
cursect = self._dict((('__name__', sectname),))
self._sections[sectname] = cursect
self._proxies[sectname] = None
# So sections can't start with a continuation line
optname = None
# no section header in the file?
elif cursect is None:
raise cp.MissingSectionHeaderError(fpname, lineno, line)
# an option line?
elif not is_multi_line:
mo = self.OPTCRE.match(line)
if mo:
# We might just have handled the last line, which could contain a quotation we want to remove
optname, vi, optval = mo.group('option', 'vi', 'value')
if vi in ('=', ':') and ';' in optval and not optval.strip().startswith('"'):
pos = optval.find(';')
if pos != -1 and optval[pos - 1].isspace():
optval = optval[:pos]
optval = optval.strip()
if optval == '""':
optval = ''
# end handle empty string
optname = self.optionxform(optname.rstrip())
if len(optval) > 1 and optval[0] == '"' and optval[-1] != '"':
is_multi_line = True
optval = string_decode(optval[1:])
# end handle multi-line
cursect[optname] = optval
else:
# check if it's an option with no value - it's just ignored by git
if not self.OPTVALUEONLY.match(line):
if not e:
e = cp.ParsingError(fpname)
e.append(lineno, repr(line))
continue
else:
line = line.rstrip()
if line.endswith('"'):
is_multi_line = False
line = line[:-1]
# end handle quotations
cursect[optname] += string_decode(line)
# END parse section or option
# END while reading
# if any parsing errors occurred, raise an exception
if e:
raise e
def _has_includes(self):
return self._merge_includes and self.has_section('include')
def read(self):
"""Reads the data stored in the files we have been initialized with. It will
ignore files that cannot be read, possibly leaving an empty configuration
:return: Nothing
:raise IOError: if a file cannot be handled"""
if self._is_initialized:
return
self._is_initialized = True
if not isinstance(self._file_or_files, (tuple, list)):
files_to_read = [self._file_or_files]
else:
files_to_read = list(self._file_or_files)
# end assure we have a copy of the paths to handle
seen = set(files_to_read)
num_read_include_files = 0
while files_to_read:
file_path = files_to_read.pop(0)
fp = file_path
file_ok = False
if hasattr(fp, "seek"):
self._read(fp, fp.name)
else:
# assume a path if it is not a file-object
try:
with open(file_path, 'rb') as fp:
file_ok = True
self._read(fp, fp.name)
except IOError:
continue
# Read includes and append those that we didn't handle yet
# We expect all paths to be normalized and absolute (and will assure that is the case)
if self._has_includes():
for _, include_path in self.items('include'):
if include_path.startswith('~'):
include_path = osp.expanduser(include_path)
if not osp.isabs(include_path):
if not file_ok:
continue
# end ignore relative paths if we don't know the configuration file path
assert osp.isabs(file_path), "Need absolute paths to be sure our cycle checks will work"
include_path = osp.join(osp.dirname(file_path), include_path)
# end make include path absolute
include_path = osp.normpath(include_path)
if include_path in seen or not os.access(include_path, os.R_OK):
continue
seen.add(include_path)
# insert included file to the top to be considered first
files_to_read.insert(0, include_path)
num_read_include_files += 1
# each include path in configuration file
# end handle includes
# END for each file object to read
# If there was no file included, we can safely write back (potentially) the configuration file
# without altering it's meaning
if num_read_include_files == 0:
self._merge_includes = False
# end
def _write(self, fp):
"""Write an .ini-format representation of the configuration state in
git compatible format"""
def write_section(name, section_dict):
fp.write(("[%s]\n" % name).encode(defenc))
for (key, value) in section_dict.items():
if key != "__name__":
fp.write(("\t%s = %s\n" % (key, self._value_to_string(value).replace('\n', '\n\t'))).encode(defenc))
# END if key is not __name__
# END section writing
if self._defaults:
write_section(cp.DEFAULTSECT, self._defaults)
for name, value in self._sections.items():
write_section(name, value)
def items(self, section_name):
""":return: list((option, value), ...) pairs of all items in the given section"""
return [(k, v) for k, v in super(GitConfigParser, self).items(section_name) if k != '__name__']
@needs_values
def write(self):
"""Write changes to our file, if there are changes at all
:raise IOError: if this is a read-only writer instance or if we could not obtain
a file lock"""
self._assure_writable("write")
if not self._dirty:
return
if isinstance(self._file_or_files, (list, tuple)):
raise AssertionError("Cannot write back if there is not exactly a single file to write to, have %i files"
% len(self._file_or_files))
# end assert multiple files
if self._has_includes():
log.debug("Skipping write-back of configuration file as include files were merged in." +
"Set merge_includes=False to prevent this.")
return
# end
fp = self._file_or_files
# we have a physical file on disk, so get a lock
is_file_lock = isinstance(fp, string_types + (FileType, ))
if is_file_lock:
self._lock._obtain_lock()
if not hasattr(fp, "seek"):
with open(self._file_or_files, "wb") as fp:
self._write(fp)
else:
fp.seek(0)
# make sure we do not overwrite into an existing file
if hasattr(fp, 'truncate'):
fp.truncate()
self._write(fp)
def _assure_writable(self, method_name):
if self.read_only:
raise IOError("Cannot execute non-constant method %s.%s" % (self, method_name))
def add_section(self, section):
"""Assures added options will stay in order"""
return super(GitConfigParser, self).add_section(section)
@property
def read_only(self):
""":return: True if this instance may change the configuration file"""
return self._read_only
def get_value(self, section, option, default=None):
"""
:param default:
If not None, the given default value will be returned in case
the option did not exist
:return: a properly typed value, either int, float or string
:raise TypeError: in case the value could not be understood
Otherwise the exceptions known to the ConfigParser will be raised."""
try:
valuestr = self.get(section, option)
except Exception:
if default is not None:
return default
raise
types = (int, float)
for numtype in types:
try:
val = numtype(valuestr)
# truncated value ?
if val != float(valuestr):
continue
return val
except (ValueError, TypeError):
continue
# END for each numeric type
# try boolean values as git uses them
vl = valuestr.lower()
if vl == 'false':
return False
if vl == 'true':
return True
if not isinstance(valuestr, string_types):
raise TypeError("Invalid value type: only int, long, float and str are allowed", valuestr)
return valuestr
def _value_to_string(self, value):
if isinstance(value, (int, float, bool)):
return str(value)
return force_text(value)
@needs_values
@set_dirty_and_flush_changes
def set_value(self, section, option, value):
"""Sets the given option in section to the given value.
It will create the section if required, and will not throw as opposed to the default
ConfigParser 'set' method.
:param section: Name of the section in which the option resides or should reside
:param option: Name of the options whose value to set
:param value: Value to set the option to. It must be a string or convertible
to a string
:return: this instance"""
if not self.has_section(section):
self.add_section(section)
self.set(section, option, self._value_to_string(value))
return self
def rename_section(self, section, new_name):
"""rename the given section to new_name
:raise ValueError: if section doesn't exit
:raise ValueError: if a section with new_name does already exist
:return: this instance
"""
if not self.has_section(section):
raise ValueError("Source section '%s' doesn't exist" % section)
if self.has_section(new_name):
raise ValueError("Destination section '%s' already exists" % new_name)
super(GitConfigParser, self).add_section(new_name)
for k, v in self.items(section):
self.set(new_name, k, self._value_to_string(v))
# end for each value to copy
# This call writes back the changes, which is why we don't have the respective decorator
self.remove_section(section)
return self