def addToSchema(self, stmts):
self._beginTxn()
propsChanged = False
typesChanged = False
#you can declare subproperties to rdf:type, rdfs:subClassOf, rdfs:subPropertyOf
#but it will only take effect in the next call to addToSchema
#also they can not be removed consistently
#thus they should be declared in the initial schemas
for stmt in stmts:
#handle "rdf1" entailment rule in the RDF Semantics spec
self._addEntailment(Statement(stmt.predicate, RDF_MS_BASE+u'type',
RDF_MS_BASE+u'Property',OBJECT_TYPE_RESOURCE))
#"rdfs4b" entailment rule (rdfs4a isn't necessary to make explicit, we just make this
#one explicit to guarantee that the object is the subject of at least one statement)
if stmt.objectType == OBJECT_TYPE_RESOURCE:
self.entailments.addStatement( Statement(stmt.object,
RDF_MS_BASE+u'type',
RDF_SCHEMA_BASE+u'Resource',OBJECT_TYPE_RESOURCE))
#"rdfs2" and "rdfs3" entailment rules: infer types from domain and range of predicate
for predicate in self.currentSuperProperties.get(stmt.predicate,[stmt.predicate]):
domains = self.domains.get(predicate, [])
for domain in domains:
key = (stmt.subject, domain)
if key not in self.inferences:
typeStmt = Statement(stmt.subject, RDF_MS_BASE+u'type',
domain, OBJECT_TYPE_RESOURCE)
self._addTypeStatement(typeStmt)
self.inferences[key] = 1
else:
self.inferences[key] += 1
if stmt.objectType != OBJECT_TYPE_RESOURCE:
continue
ranges = self.ranges.get(predicate, [])
for range in ranges:
key = (stmt.object, range)
if key not in self.inferences:
typeStmt = Statement(stmt.object, RDF_MS_BASE+u'type', range, OBJECT_TYPE_RESOURCE)
self._addTypeStatement(typeStmt)
self.inferences[key] = 1
else:
self.inferences[key] += 1
#todo: we could do a consistency check here to make sure the object type conforms
#the subclass and subproperty rules ("rdfs5" - "rdfs11") are handled dynamically
#except for "rdfs8": uuu rdf:type rdfs:Class -> uuu rdfs:subClassOf rdfs:Resource
#which isn't needed
if stmt.predicate in self.subPropPreds:
self.currentSubProperties.setdefault(stmt.object, [stmt.object]).append(stmt.subject)
#add this subproperty if this is the only reference to it so far
self.currentSubProperties.setdefault(stmt.subject, [stmt.subject])
self.currentSuperProperties.setdefault(stmt.subject, [stmt.subject]).append(stmt.object)
#add this superproperty if this is the only reference to it so far
self.currentSuperProperties.setdefault(stmt.object, [stmt.object])
#if any superproperties are subject of any domain or range statements
#deduce new type statements from existing statements
for predicate in self.currentSuperProperties[stmt.object]:
domaintypes = self.domains.get(predicate,[])
rangetypes = self.ranges.get(predicate,[])
if rangetypes or domaintypes:
for targetStmt in self.model.getStatements(predicate=predicate):
for type in domaintypes:
key = (targetStmt.subject, type)
refCount = self.inferences.get(key, 0)
if not refCount:
typeStmt = Statement(targetStmt.subject,
RDF_MS_BASE+u'type', type,
OBJECT_TYPE_RESOURCE)
self._addTypeStatement(typeStmt)
self.inferences[key ] = 1
else:
self.inferences[key ] += 1
if stmt.objectType != OBJECT_TYPE_RESOURCE:
continue
for type in rangetypes:
key = (targetStmt.object, type)
refCount = self.inferences.get(key, 0)
if not refCount:
typeStmt = Statement(targetStmt.object,
RDF_MS_BASE+u'type', type,
OBJECT_TYPE_RESOURCE)
self._addTypeStatement(typeStmt)
self.inferences[key ] = 1
else:
self.inferences[key ] += 1
propsChanged = True
elif stmt.predicate in self.subClassPreds:
self.currentSubTypes.setdefault(stmt.object, [stmt.object]).append(stmt.subject)
#add this subclass if this is the only reference to it so far
self.currentSubTypes.setdefault(stmt.subject, [stmt.subject])
self.currentSuperTypes.setdefault(stmt.subject, [stmt.subject]).append(stmt.object)
#add this superclass if this is the only reference to it so far
self.currentSuperTypes.setdefault(stmt.object, [stmt.object])
typesChanged = True
elif stmt.predicate in self.typePreds:
self._addTypeStatement(stmt, addStmt=False)
else:
self.currentSubProperties.setdefault(stmt.predicate, [stmt.predicate])
self.currentSuperProperties.setdefault(stmt.predicate, [stmt.predicate])
#if we're adding a domain or range statement infer type for resources that already have statements
#with that predicate or subproperty
if self.isCompatibleProperty(stmt.predicate, RDF_SCHEMA_BASE+u'domain'):
self.domains.setdefault(stmt.subject, []).append(stmt.object)
for predicate in self.currentSubProperties[stmt.subject]:
for targetStmt in self.model.getStatements(predicate=stmt.subject):
key = (targetStmt.subject, stmt.object)
if key not in self.inferences:
typeStmt = Statement(targetStmt.subject,
RDF_MS_BASE+u'type', stmt.object,
OBJECT_TYPE_RESOURCE)
self._addTypeStatement(typeStmt)
self.inferences[key ] = 1
else:
self.inferences[key ] += 1
if self.isCompatibleProperty(stmt.predicate, RDF_SCHEMA_BASE+u'range'):
self.ranges.setdefault(stmt.subject, []).append(stmt.object)
for predicate in self.currentSubProperties[stmt.subject]:
for targetStmt in self.model.getStatements(
predicate=stmt.subject, objecttype=OBJECT_TYPE_RESOURCE):
key = (targetStmt.object, stmt.object)
if key not in self.inferences:
typeStmt = Statement(targetStmt.object,
RDF_MS_BASE+u'type', stmt.object,
OBJECT_TYPE_RESOURCE)
self._addTypeStatement(typeStmt)
self.inferences[key] = 1
else:
self.inferences[key] += 1
if typesChanged:
self.currentSubTypes = getTransitiveClosure(self.currentSubTypes)
#XXX if self.saveSubtypes:
# self.saveSubtypes() XXX
if self.autocommit:
self.subtypes = self.currentSubTypes
if propsChanged:
self.currentSubProperties = getTransitiveClosure(self.currentSubProperties)
if self.autocommit:
self.subproperties = self.currentSubProperties
#just in case a subproperty of any of these were added
self.subClassPreds = self.currentSubProperties[self.SUBCLASSOF]
self.subPropPreds = self.currentSubProperties[self.SUBPROPOF]
self.typePreds = self.currentSubProperties[RDF_MS_BASE+u'type']
def _findJoinPreds(self, root, joins):
joinsByName = {}
simpleJoinCandidates = []
complexJoinCandidates = []
aliases = {}
for join in joins:
# for each filter
# if Eq and both sides are simple references (?label or id or ?ref.id)
# add to aliases and remove filter from join (we'll join together later)
aliases.setdefault(join.name, [])
joinsByName[join.name] = join
for filter in join.depthfirst(descendPredicate=lambda op: op is join or not isinstance(op, ResourceSetOp)):
if not isinstance(filter, Filter):
continue
for arg in filter.args:
if isinstance(arg, Eq):
leftname, leftprop = getNameIfSimpleJoinRef(arg.left, join.name, filter)
rightname, rightprop = getNameIfSimpleJoinRef(arg.right, join.name, filter)
# if both sides are either a project or label
if leftname and rightname:
# its an alias
if not leftprop and not rightprop:
# None or 0 (SUBJECT)
# its an alias
if arg.maybe:
raise QueryException("maybe on an aliasing join not allowed", arg)
if leftname != rightname:
aliases.setdefault(leftname, []).append(rightname)
aliases.setdefault(rightname, []).append(leftname)
# remove this predicate from the filter
arg.parent = None
continue
else:
# expressions like ?foo = ?bar.prop or ?a.prop = ?b.prop
candidate = (join.name, arg, leftname, leftprop, rightname, rightprop)
simpleJoinCandidates.append(candidate)
continue
# elif leftname or rightname:
# XXX support cases where one side is a complex expression
complexJoinCandidates.append(filter)
if not filter.args:
# we must have removed all its predicates so
# remove the filter and its join condition
join.removeArg(filter.parent)
# combine together joins that are just aliases of each other
# assumes join list is in doc order so taht nested joins gets subsumed by outermost join
aliases = getTransitiveClosure(aliases)
renamed = {}
removed = []
for j in joins:
for name in aliases[j.name]:
if name == j.name:
continue
renamed[name] = j.name
ja = joinsByName.get(name)
if not ja:
continue
for child in ja.args:
j.appendArg(child)
ja.name = j.name
self.prepareJoinMove(ja)
ja.parent = None
removed.append(ja)
joins = [j for j in joins if j not in removed]
import itertools
for join in itertools.chain((root,), joins):
for child in join.depthfirst(descendPredicate=lambda op: op is join or not isinstance(op, ResourceSetOp)):
if isinstance(child, (Label, Join)):
if child.name in renamed:
child.name = renamed[child.name]
elif isinstance(child, Project) and child.varref:
if child.varref in renamed:
child.varref = renamed[child.varref]
assert len(set([j.name for j in joins])) == len(joins), "join names not unique"
# now that we figured out all the aliases, we can look for join predicates
simpleJoins = []
for joinname, pred, leftname, leftprop, rightname, rightprop in simpleJoinCandidates:
leftname = renamed.get(leftname, leftname)
rightname = renamed.get(rightname, rightname)
filter = pred.parent
if leftname == rightname:
# both references point to same join, so not a join predicate after all
if pred.maybe:
raise QueryException("MAYBE can not be used on a filter that is not a join condition", pred)
if leftprop == rightprop:
# identity (a=a), so remove predicate
# XXX add user warning
pred.parent = None
if not filter.args:
filter.parent.parent = None
else:
# expression operates on more than one project, need to
# execute after both Projects have been retreived
filter.complexPredicates = True
else:
simpleJoins.append((leftname, leftprop, rightname, rightprop, filter, pred.maybe))
# pred is just a Projects so its already handled by another
# filter predicate (see makeJoinExpr() when skipRoot = True)
# , so remove this one
if not pred.siblings:
filter.parent.parent = None
else:
pred.parent = None
# xxx handle case like { ?bar ?foo.prop = func() or func(?foo) }
# aren't these complex (cross) joins but rather misplaced filters
# that belong in the ?foo join?
# check if the remaining filter predicates are complex joins
complexJoins = []
projectPreds = []
for filter in complexJoinCandidates:
if not filter.parent:
continue
join = filter.parent.parent
# if the filter predicates have reference to another join, its a complex join
# and while we're at it, collect Project predicates for maybe analysis and fixup
for pred in filter.args:
joinrefs = {}
for label in pred.depthfirst():
# check if the filter has reference to a different join
if isinstance(label, Label):
joinrefs.setdefault(label.name, []).append(label)
if label.name == join.name:
# to reduce the number of equivalent ops
# replace this with Project(SUBJECT)
newchild = Project(SUBJECT, label.name, maybe=label.maybe)
label.parent.replaceArg(label, newchild)
elif isinstance(label, Project):
if not label.varref:
label.varref = join.name
joinrefs.setdefault(label.varref, []).append(label)
propertyname = None
if isinstance(label.name, int):
if label.name == PROPERTY:
propertyname = filter.labelFromPosition(OBJECT)
else:
propertyname = label.name
if propertyname:
projectPreds.append((label.varref or join.name, propertyname, label.maybe, pred))
if len(joinrefs) == 2 and isinstance(pred, Eq):
(leftname, leftops), (rightname, rightops) = joinrefs.items()
simple = self._makeHalfSimpleJoin(pred, join.name, leftname, leftops, rightname)
if not simple: # try reverse order
simple = self._makeHalfSimpleJoin(pred, join.name, rightname, rightops, leftname)
if simple:
simpleJoins.append(simple)
else:
complexJoins.append((filter, set([leftname, rightname]), pred.maybe))
elif len(joinrefs) > 1:
complexJoins.append((filter, set(joinrefs.keys()), pred.maybe))
else:
if pred.maybe and not isinstance(pred, Project):
raise QueryException("MAYBE can not be used on a filter that is not a join condition", pred)
# if there's only 1 joinref but it not referencing the join
# that its part of, move the filter to the join that is referencing
if len(joinrefs) == 1 and iter(joinrefs).next() != join.name:
# XXX implement this
raise QueryException("Filters that refer to a different filter set are not yet implemented.")
_fixMaybeFilters(projectPreds)
return joins, simpleJoins, complexJoins
if stmt.predicate in self.subClassPreds:
try:
self.currentSubTypes[stmt.object].remove(stmt.subject)
self.currentSuperTypes[stmt.subject].remove(stmt.object)
except KeyError, ValueError:
pass#todo warn if not found
typesChanged = True
if typesChanged:
newsubtypes = {}
for k, v in self.currentSuperTypes.items():
for supertype in v:
newsubtypes.setdefault(supertype, []).append(k)
self.currentSubTypes = getTransitiveClosure(newsubtypes)
if self.autocommit:
self.subtypes = self.currentSubTypes
if propsChanged:
newsubprops = {}
for k, v in self.currentSuperProperties.items():
for superprop in v:
newsubprops.setdefault(superprop, []).append(k)
self.currentSubProperties = getTransitiveClosure(newsubprops)
if self.autocommit:
self.subproperties = self.currentSubProperties
#just in case a subproperty of any of these were removed
self.subClassPreds = self.currentSubProperties[self.SUBCLASSOF]
