Source code for SCons.Node.Python

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"""Python nodes."""

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): super().__init__() 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) -> str: """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): # Get csig() value of child as this is more efficent contents = contents + kid.get_csig() return contents
[docs] def get_contents(self) -> bytes: """Get contents for signature calculations.""" return self.get_text_contents().encode()
[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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