diff options
Diffstat (limited to 'lib/spack/spack/spec.py')
| -rw-r--r-- | lib/spack/spack/spec.py | 183 |
1 files changed, 166 insertions, 17 deletions
diff --git a/lib/spack/spack/spec.py b/lib/spack/spack/spec.py index a58e1ceb2f..aa22978217 100644 --- a/lib/spack/spack/spec.py +++ b/lib/spack/spack/spec.py @@ -971,7 +971,159 @@ class SpecBuildInterface(ObjectWrapper): @key_ordering class Spec(object): - def __init__(self, spec_like, *dep_like, **kwargs): + @staticmethod + def from_literal(spec_dict, normal=True): + """Builds a Spec from a dictionary containing the spec literal. + + The dictionary must have a single top level key, representing the root, + and as many secondary level keys as needed in the spec. + + The keys can be either a string or a Spec or a tuple containing the + Spec and the dependency types. + + Args: + spec_dict (dict): the dictionary containing the spec literal + normal (bool): if True the same key appearing at different levels + of the ``spec_dict`` will map to the same object in memory. + + Examples: + A simple spec ``foo`` with no dependencies: + + .. code-block:: python + + {'foo': None} + + A spec ``foo`` with a ``(build, link)`` dependency ``bar``: + + .. code-block:: python + + {'foo': + {'bar:build,link': None}} + + A spec with a diamond dependency and various build types: + + .. code-block:: python + + {'dt-diamond': { + 'dt-diamond-left:build,link': { + 'dt-diamond-bottom:build': None + }, + 'dt-diamond-right:build,link': { + 'dt-diamond-bottom:build,link,run': None + } + }} + + The same spec with a double copy of ``dt-diamond-bottom`` and + no diamond structure: + + .. code-block:: python + + {'dt-diamond': { + 'dt-diamond-left:build,link': { + 'dt-diamond-bottom:build': None + }, + 'dt-diamond-right:build,link': { + 'dt-diamond-bottom:build,link,run': None + } + }, normal=False} + + Constructing a spec using a Spec object as key: + + .. code-block:: python + + mpich = Spec('mpich') + libelf = Spec('libelf@1.8.11') + expected_normalized = Spec.from_literal({ + 'mpileaks': { + 'callpath': { + 'dyninst': { + 'libdwarf': {libelf: None}, + libelf: None + }, + mpich: None + }, + mpich: None + }, + }) + + """ + + # Maps a literal to a Spec, to be sure we are reusing the same object + spec_cache = LazySpecCache() + + def spec_builder(d): + # The invariant is that the top level dictionary must have + # only one key + assert len(d) == 1 + + # Construct the top-level spec + spec_like, dep_like = next(iter(d.items())) + + # If the requirements was for unique nodes (default) + # then re-use keys from the local cache. Otherwise build + # a new node every time. + if not isinstance(spec_like, Spec): + spec = spec_cache[spec_like] if normal else Spec(spec_like) + else: + spec = spec_like + + if dep_like is None: + return spec + + def name_and_dependency_types(s): + """Given a key in the dictionary containing the literal, + extracts the name of the spec and its dependency types. + + Args: + s (str): key in the dictionary containing the literal + + """ + t = s.split(':') + + if len(t) > 2: + msg = 'more than one ":" separator in key "{0}"' + raise KeyError(msg.format(s)) + + n = t[0] + if len(t) == 2: + dtypes = tuple(dt.strip() for dt in t[1].split(',')) + else: + dtypes = () + + return n, dtypes + + def spec_and_dependency_types(s): + """Given a non-string key in the literal, extracts the spec + and its dependency types. + + Args: + s (spec or tuple): either a Spec object or a tuple + composed of a Spec object and a string with the + dependency types + + """ + if isinstance(s, Spec): + return s, () + + spec_obj, dtypes = s + return spec_obj, tuple(dt.strip() for dt in dtypes.split(',')) + + # Recurse on dependencies + for s, s_dependencies in dep_like.items(): + + if isinstance(s, string_types): + dag_node, dependency_types = name_and_dependency_types(s) + else: + dag_node, dependency_types = spec_and_dependency_types(s) + + dependency_spec = spec_builder({dag_node: s_dependencies}) + spec._add_dependency(dependency_spec, dependency_types) + + return spec + + return spec_builder(spec_dict) + + def __init__(self, spec_like, **kwargs): # Copy if spec_like is a Spec. if isinstance(spec_like, Spec): self._dup(spec_like) @@ -1014,22 +1166,6 @@ class Spec(object): self.external_path = kwargs.get('external_path', None) self.external_module = kwargs.get('external_module', None) - # This allows users to construct a spec DAG with literals. - # Note that given two specs a and b, Spec(a) copies a, but - # Spec(a, b) will copy a but just add b as a dep. - deptypes = () - for dep in dep_like: - - if isinstance(dep, (list, tuple)): - # Literals can be deptypes -- if there are tuples in the - # list, they will be used as deptypes for the following Spec. - deptypes = tuple(dep) - continue - - spec = dep if isinstance(dep, Spec) else Spec(dep) - self._add_dependency(spec, deptypes) - deptypes = () - @property def external(self): return bool(self.external_path) or bool(self.external_module) @@ -2944,6 +3080,19 @@ class Spec(object): return str(self) +class LazySpecCache(collections.defaultdict): + """Cache for Specs that uses a spec_like as key, and computes lazily + the corresponding value ``Spec(spec_like``. + """ + def __init__(self): + super(LazySpecCache, self).__init__(Spec) + + def __missing__(self, key): + value = self.default_factory(key) + self[key] = value + return value + + # # These are possible token types in the spec grammar. # |