Source code for rdflib.plugins.stores.memory

#
#
from typing import (
    TYPE_CHECKING,
    Any,
    Collection,
    Dict,
    Generator,
    Iterator,
    Mapping,
    Optional,
    Set,
    Tuple,
    Union,
    overload,
)

from rdflib.store import Store
from rdflib.util import _coalesce

if TYPE_CHECKING:
    from rdflib.graph import (
        Graph,
        _ContextType,
        _ObjectType,
        _PredicateType,
        _SubjectType,
        _TriplePatternType,
        _TripleType,
    )
    from rdflib.plugins.sparql.sparql import Query, Update
    from rdflib.query import Result
    from rdflib.term import Identifier, URIRef, Variable

__all__ = ["SimpleMemory", "Memory"]

ANY = None


[docs]class SimpleMemory(Store): """\ A fast naive in memory implementation of a triple store. This triple store uses nested dictionaries to store triples. Each triple is stored in two such indices as follows spo[s][p][o] = 1 and pos[p][o][s] = 1. Authors: Michel Pelletier, Daniel Krech, Stefan Niederhauser """
[docs] def __init__( self, configuration: Optional[str] = None, identifier: Optional["Identifier"] = None, ): super(SimpleMemory, self).__init__(configuration) self.identifier = identifier # indexed by [subject][predicate][object] self.__spo: Dict[ "_SubjectType", Dict["_PredicateType", Dict["_ObjectType", int]] ] = {} # indexed by [predicate][object][subject] self.__pos: Dict[ "_PredicateType", Dict["_ObjectType", Dict["_SubjectType", int]] ] = {} # indexed by [predicate][object][subject] self.__osp: Dict[ "_ObjectType", Dict["_SubjectType", Dict["_PredicateType", int]] ] = {} self.__namespace: Dict[str, "URIRef"] = {} self.__prefix: Dict["URIRef", str] = {}
[docs] def add( self, triple: "_TripleType", context: "_ContextType", quoted: bool = False, ) -> None: """\ Add a triple to the store of triples. """ # add dictionary entries for spo[s][p][p] = 1 and pos[p][o][s] # = 1, creating the nested dictionaries where they do not yet # exits. subject, predicate, object = triple spo = self.__spo try: po = spo[subject] except: # noqa: E722 po = spo[subject] = {} try: o = po[predicate] except: # noqa: E722 o = po[predicate] = {} o[object] = 1 pos = self.__pos try: os = pos[predicate] except: # noqa: E722 os = pos[predicate] = {} try: s = os[object] except: # noqa: E722 s = os[object] = {} s[subject] = 1 osp = self.__osp try: sp = osp[object] except: # noqa: E722 sp = osp[object] = {} try: p = sp[subject] except: # noqa: E722 p = sp[subject] = {} p[predicate] = 1
[docs] def remove( self, triple_pattern: "_TriplePatternType", context: Optional["_ContextType"] = None, ) -> None: for (subject, predicate, object), c in list(self.triples(triple_pattern)): del self.__spo[subject][predicate][object] del self.__pos[predicate][object][subject] del self.__osp[object][subject][predicate]
[docs] def triples( self, triple_pattern: "_TriplePatternType", context: Optional["_ContextType"] = None, ) -> Iterator[Tuple["_TripleType", Iterator[Optional["_ContextType"]]]]: """A generator over all the triples matching""" subject, predicate, object = triple_pattern if subject != ANY: # subject is given spo = self.__spo if subject in spo: subjectDictionary = spo[subject] # noqa: N806 if predicate != ANY: # subject+predicate is given if predicate in subjectDictionary: if object != ANY: # subject+predicate+object is given if object in subjectDictionary[predicate]: yield (subject, predicate, object), self.__contexts() else: # given object not found pass else: # subject+predicate is given, object unbound for o in subjectDictionary[predicate].keys(): yield (subject, predicate, o), self.__contexts() else: # given predicate not found pass else: # subject given, predicate unbound for p in subjectDictionary.keys(): if object != ANY: # object is given if object in subjectDictionary[p]: yield (subject, p, object), self.__contexts() else: # given object not found pass else: # object unbound for o in subjectDictionary[p].keys(): yield (subject, p, o), self.__contexts() else: # given subject not found pass elif predicate != ANY: # predicate is given, subject unbound pos = self.__pos if predicate in pos: predicateDictionary = pos[predicate] # noqa: N806 if object != ANY: # predicate+object is given, subject unbound if object in predicateDictionary: for s in predicateDictionary[object].keys(): yield (s, predicate, object), self.__contexts() else: # given object not found pass else: # predicate is given, object+subject unbound for o in predicateDictionary.keys(): for s in predicateDictionary[o].keys(): yield (s, predicate, o), self.__contexts() elif object != ANY: # object is given, subject+predicate unbound osp = self.__osp if object in osp: objectDictionary = osp[object] # noqa: N806 for s in objectDictionary.keys(): for p in objectDictionary[s].keys(): yield (s, p, object), self.__contexts() else: # subject+predicate+object unbound spo = self.__spo for s in spo.keys(): subjectDictionary = spo[s] # noqa: N806 for p in subjectDictionary.keys(): for o in subjectDictionary[p].keys(): yield (s, p, o), self.__contexts()
[docs] def __len__(self, context: Optional["_ContextType"] = None) -> int: # @@ optimize i = 0 for triple in self.triples((None, None, None)): i += 1 return i
[docs] def bind(self, prefix: str, namespace: "URIRef", override: bool = True) -> None: # should be identical to `Memory.bind` bound_namespace = self.__namespace.get(prefix) bound_prefix = _coalesce( self.__prefix.get(namespace), # type error: error: Argument 1 to "get" of "Mapping" has incompatible type "Optional[URIRef]"; expected "URIRef" self.__prefix.get(bound_namespace), # type: ignore[arg-type] ) if override: if bound_prefix is not None: del self.__namespace[bound_prefix] if bound_namespace is not None: del self.__prefix[bound_namespace] self.__prefix[namespace] = prefix self.__namespace[prefix] = namespace else: # type error: Invalid index type "Optional[URIRef]" for "Dict[URIRef, str]"; expected type "URIRef" self.__prefix[_coalesce(bound_namespace, namespace)] = _coalesce( # type: ignore[index] bound_prefix, default=prefix ) # type error: Invalid index type "Optional[str]" for "Dict[str, URIRef]"; expected type "str" self.__namespace[_coalesce(bound_prefix, prefix)] = _coalesce( # type: ignore[index] bound_namespace, default=namespace )
[docs] def namespace(self, prefix: str) -> Optional["URIRef"]: return self.__namespace.get(prefix, None)
[docs] def prefix(self, namespace: "URIRef") -> Optional[str]: return self.__prefix.get(namespace, None)
[docs] def namespaces(self) -> Iterator[Tuple[str, "URIRef"]]: for prefix, namespace in self.__namespace.items(): yield prefix, namespace
def __contexts(self) -> Generator["_ContextType", None, None]: # TODO: best way to return empty generator # type error: Need type annotation for "c" return (c for c in []) # type: ignore[var-annotated] # type error: Missing return statement
[docs] def query( # type: ignore[return] self, query: Union["Query", str], initNs: Mapping[str, Any], # noqa: N803 initBindings: Mapping["Variable", "Identifier"], # noqa: N803 queryGraph: "str", # noqa: N803 **kwargs: Any, ) -> "Result": super(SimpleMemory, self).query( query, initNs, initBindings, queryGraph, **kwargs )
[docs] def update( self, update: Union["Update", str], initNs: Mapping[str, Any], # noqa: N803 initBindings: Mapping["Variable", "Identifier"], # noqa: N803 queryGraph: "str", # noqa: N803 **kwargs: Any, ) -> None: super(SimpleMemory, self).update( update, initNs, initBindings, queryGraph, **kwargs )
[docs]class Memory(Store): """\ An in memory implementation of a triple store. Same as SimpleMemory above, but is Context-aware, Graph-aware, and Formula-aware Authors: Ashley Sommer """ context_aware = True formula_aware = True graph_aware = True
[docs] def __init__( self, configuration: Optional[str] = None, identifier: Optional["Identifier"] = None, ): super(Memory, self).__init__(configuration) self.identifier = identifier # indexed by [subject][predicate][object] self.__spo: Dict[ "_SubjectType", Dict["_PredicateType", Dict["_ObjectType", int]] ] = {} # indexed by [predicate][object][subject] self.__pos: Dict[ "_PredicateType", Dict["_ObjectType", Dict["_SubjectType", int]] ] = {} # indexed by [predicate][object][subject] self.__osp: Dict[ "_ObjectType", Dict["_SubjectType", Dict["_PredicateType", int]] ] = {} self.__namespace: Dict[str, "URIRef"] = {} self.__prefix: Dict["URIRef", str] = {} self.__context_obj_map: Dict[str, "Graph"] = {} self.__tripleContexts: Dict["_TripleType", Dict[Optional[str], bool]] = {} self.__contextTriples: Dict[Optional[str], Set["_TripleType"]] = {None: set()} # all contexts used in store (unencoded) self.__all_contexts: Set["Graph"] = set() # default context information for triples self.__defaultContexts: Optional[Dict[Optional[str], bool]] = None
[docs] def add( self, triple: "_TripleType", context: "_ContextType", quoted: bool = False, ) -> None: """\ Add a triple to the store of triples. """ # add dictionary entries for spo[s][p][p] = 1 and pos[p][o][s] # = 1, creating the nested dictionaries where they do not yet # exits. Store.add(self, triple, context, quoted=quoted) if context is not None: self.__all_contexts.add(context) subject, predicate, object_ = triple spo = self.__spo try: po = spo[subject] except LookupError: po = spo[subject] = {} try: o = po[predicate] except LookupError: o = po[predicate] = {} try: _ = o[object_] # This cannot be reached if (s, p, o) was not inserted before. triple_exists = True except KeyError: o[object_] = 1 triple_exists = False self.__add_triple_context(triple, triple_exists, context, quoted) if triple_exists: # No need to insert twice this triple. return pos = self.__pos try: os = pos[predicate] except LookupError: os = pos[predicate] = {} try: s = os[object_] except LookupError: s = os[object_] = {} s[subject] = 1 osp = self.__osp try: sp = osp[object_] except LookupError: sp = osp[object_] = {} try: p = sp[subject] except LookupError: p = sp[subject] = {} p[predicate] = 1
[docs] def remove( self, triple_pattern: "_TriplePatternType", context: Optional["_ContextType"] = None, ) -> None: req_ctx = self.__ctx_to_str(context) for triple, c in self.triples(triple_pattern, context=context): subject, predicate, object_ = triple for ctx in self.__get_context_for_triple(triple): if context is not None and req_ctx != ctx: continue self.__remove_triple_context(triple, ctx) ctxs = self.__get_context_for_triple(triple, skipQuoted=True) if None in ctxs and (context is None or len(ctxs) == 1): # remove from default graph too self.__remove_triple_context(triple, None) if len(self.__get_context_for_triple(triple)) == 0: del self.__spo[subject][predicate][object_] del self.__pos[predicate][object_][subject] del self.__osp[object_][subject][predicate] del self.__tripleContexts[triple] if ( req_ctx is not None and req_ctx in self.__contextTriples and len(self.__contextTriples[req_ctx]) == 0 ): # all triples are removed out of this context # and it's not the default context so delete it del self.__contextTriples[req_ctx] if ( triple_pattern == (None, None, None) and context in self.__all_contexts and not self.graph_aware ): # remove the whole context self.__all_contexts.remove(context)
[docs] def triples( self, triple_pattern: "_TriplePatternType", context: Optional["_ContextType"] = None, ) -> Generator[ Tuple["_TripleType", Generator[Optional["_ContextType"], None, None]], None, None, ]: """A generator over all the triples matching""" req_ctx = self.__ctx_to_str(context) subject, predicate, object_ = triple_pattern # all triples case (no triple parts given as pattern) if subject is None and predicate is None and object_ is None: # Just dump all known triples from the given graph if req_ctx not in self.__contextTriples: return for triple in self.__contextTriples[req_ctx].copy(): yield triple, self.__contexts(triple) # optimize "triple in graph" case (all parts given) elif subject is not None and predicate is not None and object_ is not None: # type error: Incompatible types in assignment (expression has type "Tuple[Optional[IdentifiedNode], Optional[IdentifiedNode], Optional[Identifier]]", variable has type "Tuple[IdentifiedNode, IdentifiedNode, Identifier]") # NOTE on type error: at this point, all elements of triple_pattern # is not None, so it has the same type as triple triple = triple_pattern # type: ignore[assignment] try: _ = self.__spo[subject][predicate][object_] if self.__triple_has_context(triple, req_ctx): yield triple, self.__contexts(triple) except KeyError: return elif subject is not None: # subject is given spo = self.__spo if subject in spo: subjectDictionary = spo[subject] # noqa: N806 if predicate is not None: # subject+predicate is given if predicate in subjectDictionary: if object_ is not None: # subject+predicate+object is given if object_ in subjectDictionary[predicate]: triple = (subject, predicate, object_) if self.__triple_has_context(triple, req_ctx): yield triple, self.__contexts(triple) else: # given object not found pass else: # subject+predicate is given, object unbound for o in list(subjectDictionary[predicate].keys()): triple = (subject, predicate, o) if self.__triple_has_context(triple, req_ctx): yield triple, self.__contexts(triple) else: # given predicate not found pass else: # subject given, predicate unbound for p in list(subjectDictionary.keys()): if object_ is not None: # object is given if object_ in subjectDictionary[p]: triple = (subject, p, object_) if self.__triple_has_context(triple, req_ctx): yield triple, self.__contexts(triple) else: # given object not found pass else: # object unbound for o in list(subjectDictionary[p].keys()): triple = (subject, p, o) if self.__triple_has_context(triple, req_ctx): yield triple, self.__contexts(triple) else: # given subject not found pass elif predicate is not None: # predicate is given, subject unbound pos = self.__pos if predicate in pos: predicateDictionary = pos[predicate] # noqa: N806 if object_ is not None: # predicate+object is given, subject unbound if object_ in predicateDictionary: for s in list(predicateDictionary[object_].keys()): triple = (s, predicate, object_) if self.__triple_has_context(triple, req_ctx): yield triple, self.__contexts(triple) else: # given object not found pass else: # predicate is given, object+subject unbound for o in list(predicateDictionary.keys()): for s in list(predicateDictionary[o].keys()): triple = (s, predicate, o) if self.__triple_has_context(triple, req_ctx): yield triple, self.__contexts(triple) elif object_ is not None: # object is given, subject+predicate unbound osp = self.__osp if object_ in osp: objectDictionary = osp[object_] # noqa: N806 for s in list(objectDictionary.keys()): for p in list(objectDictionary[s].keys()): triple = (s, p, object_) if self.__triple_has_context(triple, req_ctx): yield triple, self.__contexts(triple) else: # subject+predicate+object unbound # Shouldn't get here if all other cases above worked correctly. spo = self.__spo for s in list(spo.keys()): subjectDictionary = spo[s] # noqa: N806 for p in list(subjectDictionary.keys()): for o in list(subjectDictionary[p].keys()): triple = (s, p, o) if self.__triple_has_context(triple, req_ctx): yield triple, self.__contexts(triple)
[docs] def bind(self, prefix: str, namespace: "URIRef", override: bool = True) -> None: # should be identical to `SimpleMemory.bind` bound_namespace = self.__namespace.get(prefix) bound_prefix = _coalesce( self.__prefix.get(namespace), # type error: error: Argument 1 to "get" of "Mapping" has incompatible type "Optional[URIRef]"; expected "URIRef" self.__prefix.get(bound_namespace), # type: ignore[arg-type] ) if override: if bound_prefix is not None: del self.__namespace[bound_prefix] if bound_namespace is not None: del self.__prefix[bound_namespace] self.__prefix[namespace] = prefix self.__namespace[prefix] = namespace else: # type error: Invalid index type "Optional[URIRef]" for "Dict[URIRef, str]"; expected type "URIRef" self.__prefix[_coalesce(bound_namespace, namespace)] = _coalesce( # type: ignore[index] bound_prefix, default=prefix ) # type error: Invalid index type "Optional[str]" for "Dict[str, URIRef]"; expected type "str" # type error: Incompatible types in assignment (expression has type "Optional[URIRef]", target has type "URIRef") self.__namespace[_coalesce(bound_prefix, prefix)] = _coalesce( # type: ignore[index] bound_namespace, default=namespace )
[docs] def namespace(self, prefix: str) -> Optional["URIRef"]: return self.__namespace.get(prefix, None)
[docs] def prefix(self, namespace: "URIRef") -> Optional[str]: return self.__prefix.get(namespace, None)
[docs] def namespaces(self) -> Iterator[Tuple[str, "URIRef"]]: for prefix, namespace in self.__namespace.items(): yield prefix, namespace
[docs] def contexts( self, triple: Optional["_TripleType"] = None ) -> Generator["_ContextType", None, None]: if triple is None or triple == (None, None, None): return (context for context in self.__all_contexts) subj, pred, obj = triple try: _ = self.__spo[subj][pred][obj] return self.__contexts(triple) except KeyError: return (_ for _ in [])
[docs] def __len__(self, context: Optional["_ContextType"] = None) -> int: ctx = self.__ctx_to_str(context) if ctx not in self.__contextTriples: return 0 return len(self.__contextTriples[ctx])
[docs] def add_graph(self, graph: "Graph") -> None: if not self.graph_aware: Store.add_graph(self, graph) else: self.__all_contexts.add(graph)
[docs] def remove_graph(self, graph: "Graph") -> None: if not self.graph_aware: Store.remove_graph(self, graph) else: self.remove((None, None, None), graph) try: self.__all_contexts.remove(graph) except KeyError: pass # we didn't know this graph, no problem
# internal utility methods below def __add_triple_context( self, triple: "_TripleType", triple_exists: bool, context: Optional["_ContextType"], quoted: bool, ) -> None: """add the given context to the set of contexts for the triple""" ctx = self.__ctx_to_str(context) quoted = bool(quoted) if triple_exists: # we know the triple exists somewhere in the store try: triple_context = self.__tripleContexts[triple] except KeyError: # triple exists with default ctx info # start with a copy of the default ctx info # type error: Item "None" of "Optional[Dict[Optional[str], bool]]" has no attribute "copy" triple_context = self.__tripleContexts[ triple ] = self.__defaultContexts.copy() # type: ignore[union-attr] triple_context[ctx] = quoted if not quoted: triple_context[None] = quoted else: # the triple didn't exist before in the store if quoted: # this context only triple_context = self.__tripleContexts[triple] = {ctx: quoted} else: # default context as well triple_context = self.__tripleContexts[triple] = { ctx: quoted, None: quoted, } # if the triple is not quoted add it to the default context if not quoted: self.__contextTriples[None].add(triple) # always add the triple to given context, making sure it's initialized if ctx not in self.__contextTriples: self.__contextTriples[ctx] = set() self.__contextTriples[ctx].add(triple) # if this is the first ever triple in the store, set default ctx info if self.__defaultContexts is None: self.__defaultContexts = triple_context # if the context info is the same as default, no need to store it if triple_context == self.__defaultContexts: del self.__tripleContexts[triple] def __get_context_for_triple( self, triple: "_TripleType", skipQuoted: bool = False # noqa: N803 ) -> Collection[Optional[str]]: """return a list of contexts (str) for the triple, skipping quoted contexts if skipQuoted==True""" ctxs = self.__tripleContexts.get(triple, self.__defaultContexts) if not skipQuoted: # type error: Item "None" of "Optional[Dict[Optional[str], bool]]" has no attribute "keys" return ctxs.keys() # type: ignore[union-attr] # type error: Item "None" of "Optional[Dict[Optional[str], bool]]" has no attribute "items" return [ctx for ctx, quoted in ctxs.items() if not quoted] # type: ignore[union-attr] def __triple_has_context(self, triple: "_TripleType", ctx: Optional[str]) -> bool: """return True if the triple exists in the given context""" # type error: Unsupported right operand type for in ("Optional[Dict[Optional[str], bool]]") return ctx in self.__tripleContexts.get(triple, self.__defaultContexts) # type: ignore[operator] def __remove_triple_context(self, triple: "_TripleType", ctx): """remove the context from the triple""" # type error: Item "None" of "Optional[Dict[Optional[str], bool]]" has no attribute "copy" ctxs = self.__tripleContexts.get(triple, self.__defaultContexts).copy() # type: ignore[union-attr] del ctxs[ctx] if ctxs == self.__defaultContexts: del self.__tripleContexts[triple] else: self.__tripleContexts[triple] = ctxs self.__contextTriples[ctx].remove(triple) @overload def __ctx_to_str(self, ctx: "_ContextType") -> str: ... @overload def __ctx_to_str(self, ctx: None) -> None: ... def __ctx_to_str(self, ctx: Optional["_ContextType"]) -> Optional[str]: if ctx is None: return None try: # ctx could be a graph. In that case, use its identifier ctx_str = "{}:{}".format(ctx.identifier.__class__.__name__, ctx.identifier) self.__context_obj_map[ctx_str] = ctx return ctx_str except AttributeError: # otherwise, ctx should be a URIRef or BNode or str # NOTE on type errors: This is actually never called with ctx value as str in all unit tests, so this seems like it should just not be here. # type error: Subclass of "Graph" and "str" cannot exist: would have incompatible method signatures if isinstance(ctx, str): # type: ignore[unreachable] # type error: Statement is unreachable ctx_str = "{}:{}".format(ctx.__class__.__name__, ctx) # type: ignore[unreachable] if ctx_str in self.__context_obj_map: return ctx_str self.__context_obj_map[ctx_str] = ctx return ctx_str raise RuntimeError("Cannot use that type of object as a Graph context") def __contexts( self, triple: "_TripleType" ) -> Generator["_ContextType", None, None]: """return a generator for all the non-quoted contexts (dereferenced) the encoded triple appears in""" # type error: Argument 2 to "get" of "Mapping" has incompatible type "str"; expected "Optional[Graph]" return ( self.__context_obj_map.get(ctx_str, ctx_str) # type: ignore[arg-type] for ctx_str in self.__get_context_for_triple(triple, skipQuoted=True) if ctx_str is not None ) # type error: Missing return statement
[docs] def query( # type: ignore[return] self, query: Union["Query", str], initNs: Mapping[str, Any], # noqa: N803 initBindings: Mapping["Variable", "Identifier"], # noqa: N803 queryGraph: "str", **kwargs, ) -> "Result": super(Memory, self).query(query, initNs, initBindings, queryGraph, **kwargs)
[docs] def update( self, update: Union["Update", Any], initNs: Mapping[str, Any], # noqa: N803 initBindings: Mapping["Variable", "Identifier"], # noqa: N803 queryGraph: "str", **kwargs, ) -> None: super(Memory, self).update(update, initNs, initBindings, queryGraph, **kwargs)