"""scons.Node.Python
Python nodes.
"""
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# The above copyright notice and this permission notice shall be included
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# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
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__revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
import SCons.Node
_memo_lookup_map = {}
[docs]class ValueNodeInfo(SCons.Node.NodeInfoBase):
__slots__ = ('csig',)
current_version_id = 2
field_list = ['csig']
[docs] def str_to_node(self, s):
return ValueWithMemo(s)
def __getstate__(self):
"""
Return all fields that shall be pickled. Walk the slots in the class
hierarchy and add those to the state dictionary. If a '__dict__' slot
is available, copy all entries to the dictionary. Also include the
version id, which is fixed for all instances of a class.
"""
state = getattr(self, '__dict__', {}).copy()
for obj in type(self).mro():
for name in getattr(obj, '__slots__', ()):
if hasattr(self, name):
state[name] = getattr(self, name)
state['_version_id'] = self.current_version_id
try:
del state['__weakref__']
except KeyError:
pass
return state
def __setstate__(self, state):
"""
Restore the attributes from a pickled state.
"""
# TODO check or discard version
del state['_version_id']
for key, value in state.items():
if key not in ('__weakref__',):
setattr(self, key, value)
[docs]class ValueBuildInfo(SCons.Node.BuildInfoBase):
__slots__ = ()
current_version_id = 2
[docs]class Value(SCons.Node.Node):
"""A class for Python variables, typically passed on the command line
or generated by a script, but not from a file or some other source.
"""
NodeInfo = ValueNodeInfo
BuildInfo = ValueBuildInfo
def __init__(self, value, built_value=None, name=None):
SCons.Node.Node.__init__(self)
self.value = value
self.changed_since_last_build = 6
self.store_info = 0
if built_value is not None:
self.built_value = built_value
# Set a name so it can be a child of a node and not break
# its parent's implementation of Node.get_contents.
if name:
self.name = name
else:
self.name = str(value)
[docs] def str_for_display(self):
return repr(self.value)
def __str__(self):
return str(self.value)
[docs] def make_ready(self):
self.get_csig()
[docs] def build(self, **kw):
if not hasattr(self, 'built_value'):
SCons.Node.Node.build(self, **kw)
is_up_to_date = SCons.Node.Node.children_are_up_to_date
[docs] def is_under(self, dir):
# Make Value nodes get built regardless of
# what directory scons was run from. Value nodes
# are outside the filesystem:
return 1
[docs] def write(self, built_value):
"""Set the value of the node."""
self.built_value = built_value
[docs] def read(self):
"""Return the value. If necessary, the value is built."""
self.build()
if not hasattr(self, 'built_value'):
self.built_value = self.value
return self.built_value
[docs] def get_text_contents(self):
"""By the assumption that the node.built_value is a
deterministic product of the sources, the contents of a Value
are the concatenation of all the contents of its sources. As
the value need not be built when get_contents() is called, we
cannot use the actual node.built_value."""
###TODO: something reasonable about universal newlines
contents = str(self.value)
for kid in self.children(None):
contents = contents + kid.get_contents().decode()
return contents
[docs] def get_contents(self):
"""
Get contents for signature calculations.
:return: bytes
"""
text_contents = self.get_text_contents()
try:
return text_contents.encode()
except UnicodeDecodeError:
# Already encoded as python2 str are bytes
return text_contents
[docs] def changed_since_last_build(self, target, prev_ni):
cur_csig = self.get_csig()
try:
return cur_csig != prev_ni.csig
except AttributeError:
return 1
[docs] def get_csig(self, calc=None):
"""Because we're a Python value node and don't have a real
timestamp, we get to ignore the calculator and just use the
value contents.
Returns string. Ideally string of hex digits. (Not bytes)
"""
try:
return self.ninfo.csig
except AttributeError:
pass
contents = self.get_text_contents()
self.get_ninfo().csig = contents
return contents
[docs]def ValueWithMemo(value, built_value=None, name=None):
"""
Memoized Value() node factory.
"""
global _memo_lookup_map
# No current support for memoizing a value that needs to be built.
if built_value:
return Value(value, built_value, name=name)
try:
memo_lookup_key = hash((value, name))
except TypeError:
# Non-primitive types will hit this codepath.
return Value(value, name=name)
try:
return _memo_lookup_map[memo_lookup_key]
except KeyError:
v = Value(value, built_value, name)
_memo_lookup_map[memo_lookup_key] = v
return v
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