knowrob::QueryableStorage Class Reference

#include <QueryableStorage.h>

Inheritance diagram for knowrob::QueryableStorage:

Collaboration diagram for knowrob::QueryableStorage:

Public Member Functions
	QueryableStorage (StorageFeatures features=StorageFeature::NothingSpecial)
	~QueryableStorage () override=default
virtual bool	isPersistent () const =0
virtual void	foreach (const TripleVisitor &visitor) const
virtual void	batch (const TripleHandler &callback) const =0
virtual void	batchOrigin (std::string_view origin, const TripleHandler &callback)=0
virtual bool	contains (const Triple &triple)
virtual void	match (const TriplePattern &query, const TripleVisitor &visitor)
virtual void	query (const GraphQueryPtr &query, const BindingsHandler &callback)=0
virtual void	count (const ResourceCounter &callback) const =0
bool	exportTo (const std::string &filename, semweb::TripleFormat format=semweb::RDF_XML) const
std::vector< VersionedOriginPtr >	getOrigins ()
std::optional< std::string >	getVersionOfOrigin (std::string_view origin)
void	setVersionOfOrigin (std::string_view origin, std::string_view version)
void	dropSessionOrigins ()
GraphQueryExpansionPtr	expand (const GraphQueryPtr &q)
	QueryableStorage (StorageFeatures features=StorageFeature::NothingSpecial)
	~QueryableStorage () override=default
virtual bool	isPersistent () const =0
virtual void	foreach (const TripleVisitor &visitor) const
virtual void	batch (const TripleHandler &callback) const =0
virtual void	batchOrigin (std::string_view origin, const TripleHandler &callback)=0
virtual bool	contains (const Triple &triple)
virtual void	match (const TriplePattern &query, const TripleVisitor &visitor)
virtual void	query (const GraphQueryPtr &query, const BindingsHandler &callback)=0
virtual void	count (const ResourceCounter &callback) const =0
bool	exportTo (const std::string &filename, semweb::TripleFormat format=semweb::RDF_XML) const
std::vector< VersionedOriginPtr >	getOrigins ()
std::optional< std::string >	getVersionOfOrigin (std::string_view origin)
void	setVersionOfOrigin (std::string_view origin, std::string_view version)
void	dropSessionOrigins ()
GraphQueryExpansionPtr	expand (const GraphQueryPtr &q)
Public Member Functions inherited from knowrob::Storage
	Storage (StorageFeatures features=StorageFeature::NothingSpecial)
virtual	~Storage ()=default
PluginLanguage	storageLanguage () const
const auto &	vocabulary () const
void	setVocabulary (std::shared_ptr< Vocabulary > vocabulary)
bool	supports (StorageFeature feature) const
virtual bool	insertOne (const Triple &triple)=0
virtual bool	insertAll (const TripleContainerPtr &triples)=0
virtual bool	removeOne (const Triple &triple)=0
virtual bool	removeAll (const TripleContainerPtr &triples)=0
virtual bool	removeAllWithOrigin (std::string_view origin)=0
virtual bool	initializeBackend (const PropertyTree &config)=0
std::optional< std::string >	getVersionOfOrigin (std::string_view origin) const
void	setVersionOfOrigin (std::string_view origin, std::optional< std::string_view > version)
	Storage (StorageFeatures features=StorageFeature::NothingSpecial)
virtual	~Storage ()=default
PluginLanguage	storageLanguage () const
const auto &	vocabulary () const
void	setVocabulary (std::shared_ptr< Vocabulary > vocabulary)
bool	supports (StorageFeature feature) const
virtual bool	insertOne (const Triple &triple)=0
virtual bool	insertAll (const TripleContainerPtr &triples)=0
virtual bool	removeOne (const Triple &triple)=0
virtual bool	removeAll (const TripleContainerPtr &triples)=0
virtual bool	removeAllWithOrigin (std::string_view origin)=0
virtual bool	initializeBackend (const PropertyTree &config)=0
std::optional< std::string >	getVersionOfOrigin (std::string_view origin) const
void	setVersionOfOrigin (std::string_view origin, std::optional< std::string_view > version)
Public Member Functions inherited from knowrob::DataSourceHandler
	DataSourceHandler ()=default
virtual	~DataSourceHandler ()=default
void	addDataHandler (const std::string &format, const DataSourceLoader &fn)
bool	loadDataSource (const DataSourcePtr &dataSource)
bool	hasDataHandler (const DataSourcePtr &dataSource) const
	DataSourceHandler ()=default
virtual	~DataSourceHandler ()=default
void	addDataHandler (const std::string &format, const DataSourceLoader &fn)
bool	loadDataSource (const DataSourcePtr &dataSource)
bool	hasDataHandler (const DataSourcePtr &dataSource) const

Static Public Member Functions
static std::shared_ptr< AnswerYes >	yes (const GraphPathQueryPtr &original, const GraphQueryExpansionPtr &expansion, const BindingsPtr &bindings)
static std::shared_ptr< AnswerNo >	no (const GraphPathQueryPtr &q)
static std::shared_ptr< AnswerYes >	yes (const GraphPathQueryPtr &original, const GraphQueryExpansionPtr &expansion, const BindingsPtr &bindings)
static std::shared_ptr< AnswerNo >	no (const GraphPathQueryPtr &q)

Static Public Attributes
static AtomPtr	versionProperty = IRIAtom::Tabled("http://knowrob.org/kb/knowrob.owl#hasVersionOfOrigin")

Additional Inherited Members
Protected Member Functions inherited from knowrob::Storage
void	enableFeature (StorageFeature feature)
void	setStorageLanguage (PluginLanguage storageLanguage)
void	enableFeature (StorageFeature feature)
void	setStorageLanguage (PluginLanguage storageLanguage)
Protected Member Functions inherited from knowrob::DataSourceHandler
virtual bool	loadDataSourceWithUnknownFormat (const DataSourcePtr &)
virtual bool	loadDataSourceWithUnknownFormat (const DataSourcePtr &)
Protected Attributes inherited from knowrob::Storage
std::map< std::string, std::string >	originVersions_
std::shared_ptr< Vocabulary >	vocabulary_
StorageFeatures	features_
PluginLanguage	storageLanguage_
Protected Attributes inherited from knowrob::DataSourceHandler
std::map< std::string, DataSourceLoader >	dataSourceHandler_

Detailed Description

A backend that can be queried.

Definition at line 27 of file QueryableStorage.h.

Constructor & Destructor Documentation

QueryableStorage() [1/2]

QueryableStorage::QueryableStorage ( StorageFeatures  features = StorageFeature::NothingSpecial )

explicit

Definition at line 21 of file QueryableStorage.cpp.

        : Storage(features) {
}

~QueryableStorage() [1/2]

knowrob::QueryableStorage::~QueryableStorage ( )

overridedefault

QueryableStorage() [2/2]

knowrob::QueryableStorage::QueryableStorage ( StorageFeatures  features = StorageFeature::NothingSpecial )

explicit

~QueryableStorage() [2/2]

knowrob::QueryableStorage::~QueryableStorage ( )

overridedefault

Member Function Documentation

batch() [1/2]

virtual void knowrob::QueryableStorage::batch ( const TripleHandler &  callback ) const

pure virtual

Iterate over all triples in the model.

Parameters

callback

the callback to handle the triples.

Returns

true if the iteration was successful.

Implemented in knowrob::RedlandModel, knowrob::MongoKnowledgeGraph, knowrob::PrologBackend, knowrob::RedlandModel, knowrob::MongoKnowledgeGraph, and knowrob::PrologBackend.

batch() [2/2]

virtual void knowrob::QueryableStorage::batch ( const TripleHandler &  callback ) const

pure virtual

Iterate over all triples in the model.

Parameters

callback

the callback to handle the triples.

Returns

true if the iteration was successful.

Implemented in knowrob::RedlandModel, knowrob::MongoKnowledgeGraph, knowrob::PrologBackend, knowrob::RedlandModel, knowrob::MongoKnowledgeGraph, and knowrob::PrologBackend.

batchOrigin() [1/2]

virtual void knowrob::QueryableStorage::batchOrigin ( std::string_view  origin, const TripleHandler &  callback  )

pure virtual

Iterate over all triples in the model that have a given origin.

Parameters

origin	the origin of the triples.
callback	the callback to handle the triples.

Returns

true if the iteration was successful.

Implemented in knowrob::RedlandModel, knowrob::MongoKnowledgeGraph, knowrob::PrologBackend, knowrob::RedlandModel, knowrob::MongoKnowledgeGraph, and knowrob::PrologBackend.

batchOrigin() [2/2]

virtual void knowrob::QueryableStorage::batchOrigin ( std::string_view  origin, const TripleHandler &  callback  )

pure virtual

Iterate over all triples in the model that have a given origin.

Parameters

origin	the origin of the triples.
callback	the callback to handle the triples.

Returns

true if the iteration was successful.

Implemented in knowrob::RedlandModel, knowrob::MongoKnowledgeGraph, knowrob::PrologBackend, knowrob::RedlandModel, knowrob::MongoKnowledgeGraph, and knowrob::PrologBackend.

contains() [1/2]

bool QueryableStorage::contains ( const Triple &  triple )

virtual

Parameters

triple

a framed triple.

Returns

true if the model contains the triple.

Reimplemented in knowrob::RedlandModel, and knowrob::RedlandModel.

Definition at line 84 of file QueryableStorage.cpp.

                                                    {
    bool hasTriple = false;
    match(TriplePattern(triple), [&hasTriple](const TriplePtr &) {
        hasTriple = true;
    });
    return hasTriple;
}

contains() [2/2]

virtual bool knowrob::QueryableStorage::contains ( const Triple &  triple )

virtual

Parameters

triple

a framed triple.

Returns

true if the model contains the triple.

Reimplemented in knowrob::RedlandModel, and knowrob::RedlandModel.

count() [1/2]

virtual void knowrob::QueryableStorage::count ( const ResourceCounter &  callback ) const

pure virtual

Parameters

callback

a function that is called for each resource and its count.

Implemented in knowrob::SPARQLBackend, knowrob::MongoKnowledgeGraph, knowrob::PrologBackend, knowrob::SPARQLBackend, knowrob::MongoKnowledgeGraph, and knowrob::PrologBackend.

count() [2/2]

virtual void knowrob::QueryableStorage::count ( const ResourceCounter &  callback ) const

pure virtual

Parameters

callback

a function that is called for each resource and its count.

Implemented in knowrob::SPARQLBackend, knowrob::MongoKnowledgeGraph, knowrob::PrologBackend, knowrob::SPARQLBackend, knowrob::MongoKnowledgeGraph, and knowrob::PrologBackend.

dropSessionOrigins() [1/2]

void QueryableStorage::dropSessionOrigins

(

)

Delete triples that have been asserted from a "session" origin.

Definition at line 53 of file QueryableStorage.cpp.

                                          {
    removeAllWithOrigin(ImportHierarchy::ORIGIN_USER);
    removeAllWithOrigin(ImportHierarchy::ORIGIN_REASONER);
    removeAllWithOrigin(ImportHierarchy::ORIGIN_SESSION);
}

dropSessionOrigins() [2/2]

void knowrob::QueryableStorage::dropSessionOrigins

(

)

Delete triples that have been asserted from a "session" origin.

expand() [1/2]

GraphQueryExpansionPtr QueryableStorage::expand

(

const GraphQueryPtr &

q

)

Compute the expansion of a graph path query.

Parameters

q	a graph path query.

Returns

the expansion of the query.

Definition at line 363 of file QueryableStorage.cpp.

                                                                      {
    // Expand the query. Currently, this is mainly used to compute the answer frame here.
    // But also to insert some builtins for occasional triples.
    auto exp_ctx = std::make_shared<GraphQueryExpansion>();
    exp_ctx->query_ctx = q->ctx();
    exp_ctx->with_reassignment = supports(StorageFeature::ReAssignment);
    exp_ctx->expanded = expand_query(q, *exp_ctx);
    return exp_ctx;
}

expand() [2/2]

GraphQueryExpansionPtr knowrob::QueryableStorage::expand

(

const GraphQueryPtr &

q

)

Compute the expansion of a graph path query.

Parameters

q	a graph path query.

Returns

the expansion of the query.

exportTo() [1/2]

bool QueryableStorage::exportTo	(	const std::string &	filename,
		semweb::TripleFormat	format = semweb::RDF_XML
	)		const

Export all triples in the model to a file.

Parameters

filename	the name of the file to export to.
format	the format of the output file.

Returns

true if the export was successful

Definition at line 373 of file QueryableStorage.cpp.

                                         {
    // collects all triples per subject
    semweb::ExportedTriples subjectTriples;
    // iterate over all triples in the storage
    batch([&](const TripleContainerPtr &container) {
        for (auto &triple: *container) {
            // collect triples per subject
            auto tripleCopy = std::make_shared<TripleCopy>(*triple.ptr);
            auto needle = subjectTriples.find(tripleCopy->subject());
            if (needle == subjectTriples.end()) {
                // if the subject is not yet in the map, insert it
                needle = subjectTriples.insert(std::make_pair(
                    tripleCopy->subject(), std::vector<std::shared_ptr<Triple>>())).first;
 
            }
            needle->second.push_back(tripleCopy);
        }
    });
    // write all triples to the file
    return semweb::TripleFormatter::exportTo(subjectTriples, filename, format);
}

exportTo() [2/2]

bool knowrob::QueryableStorage::exportTo	(	const std::string &	filename,
		semweb::TripleFormat	format = semweb::RDF_XML
	)		const

Export all triples in the model to a file.

Parameters

filename	the name of the file to export to.
format	the format of the output file.

Returns

true if the export was successful

foreach() [1/2]

void QueryableStorage::foreach ( const TripleVisitor &  visitor ) const

virtual

Iterate over all triples in the model.

Parameters

visitor

the callback to handle the triples.

Returns

true if the iteration was successful.

Reimplemented in knowrob::MongoKnowledgeGraph, and knowrob::MongoKnowledgeGraph.

Definition at line 92 of file QueryableStorage.cpp.

                                                                 {
    batch([&](const TripleContainerPtr &container) {
        for (auto &triple: *container) {
            visitor(triple);
        }
    });
}

foreach() [2/2]

virtual void knowrob::QueryableStorage::foreach ( const TripleVisitor &  visitor ) const

virtual

Iterate over all triples in the model.

Parameters

visitor

the callback to handle the triples.

Returns

true if the iteration was successful.

Reimplemented in knowrob::MongoKnowledgeGraph, and knowrob::MongoKnowledgeGraph.

getOrigins() [1/2]

std::vector< VersionedOriginPtr > QueryableStorage::getOrigins

(

)

Returns

a list of all origins that have been asserted.

Definition at line 25 of file QueryableStorage.cpp.

                                                           {
    static auto v_origin = std::make_shared<Variable>("Origin");
    static auto v_version = std::make_shared<Variable>("Version");
    std::vector<VersionedOriginPtr> origins;
    match(TriplePattern(v_origin, versionProperty, v_version),
          [&](const TriplePtr &triple) {
              origins.push_back(std::make_shared<VersionedOrigin>(triple->subject(), triple->valueAsString()));
          });
    return origins;
}

getOrigins() [2/2]

std::vector<VersionedOriginPtr> knowrob::QueryableStorage::getOrigins

(

)

Returns

a list of all origins that have been asserted.

getVersionOfOrigin() [1/2]

std::optional< std::string > QueryableStorage::getVersionOfOrigin

(

std::string_view

origin

)

Parameters

origin

an origin string.

Returns

the version of the origin, or an empty optional if the origin is unknown.

Definition at line 45 of file QueryableStorage.cpp.

                                                                                 {
    static auto v_version = std::make_shared<Variable>("Version");
    std::optional<std::string> version;
    match(TriplePattern(std::make_shared<Atom>(origin), versionProperty, v_version),
          [&](const TriplePtr &triple) { version = triple->createStringValue(); });
    return version;
}

getVersionOfOrigin() [2/2]

std::optional<std::string> knowrob::QueryableStorage::getVersionOfOrigin

(

std::string_view

origin

)

Parameters

origin

an origin string.

Returns

the version of the origin, or an empty optional if the origin is unknown.

isPersistent() [1/2]

virtual bool knowrob::QueryableStorage::isPersistent ( ) const

pure virtual

Returns

true if the backend is persistent.

Implemented in knowrob::RedlandModel, knowrob::MongoKnowledgeGraph, knowrob::PrologBackend, knowrob::RedlandModel, knowrob::MongoKnowledgeGraph, and knowrob::PrologBackend.

isPersistent() [2/2]

virtual bool knowrob::QueryableStorage::isPersistent ( ) const

pure virtual

Returns

true if the backend is persistent.

Implemented in knowrob::RedlandModel, knowrob::MongoKnowledgeGraph, knowrob::PrologBackend, knowrob::RedlandModel, knowrob::MongoKnowledgeGraph, and knowrob::PrologBackend.

match() [1/2]

void QueryableStorage::match ( const TriplePattern &  query, const TripleVisitor &  visitor  )

virtual

Parameters

query	a framed triple pattern.
visitor	a function that is called for each matching framed triple.

Reimplemented in knowrob::RedlandModel, knowrob::MongoKnowledgeGraph, knowrob::RedlandModel, and knowrob::MongoKnowledgeGraph.

Definition at line 69 of file QueryableStorage.cpp.

                                                                                 {
    auto graph_query = std::make_shared<GraphQuery>(
            std::make_shared<GraphPattern>(std::make_shared<TriplePattern>(q)),
            DefaultQueryContext());
    query(graph_query, [&](const BindingsPtr &bindings) {
        TriplePtr triplePtr;
        // create a triple view that holds a reference to the bindings.
        // this is done to allow the visitor to take over the ownership of the triple.
        triplePtr.ptr = new TripleView_withBindings(bindings);
        triplePtr.owned = true;
        q.instantiateInto(*triplePtr, bindings);
        visitor(triplePtr);
    });
}

match() [2/2]

virtual void knowrob::QueryableStorage::match ( const TriplePattern &  query, const TripleVisitor &  visitor  )

virtual

Parameters

query	a framed triple pattern.
visitor	a function that is called for each matching framed triple.

Reimplemented in knowrob::RedlandModel, knowrob::MongoKnowledgeGraph, knowrob::RedlandModel, and knowrob::MongoKnowledgeGraph.

no() [1/2]

std::shared_ptr< AnswerNo > QueryableStorage::no ( const GraphPathQueryPtr &  q )

static

Generates a negative answer to a query.

Parameters

q	a graph path query.

Returns

a negative answer to the query.

Definition at line 138 of file QueryableStorage.cpp.

                                                                       {
    static const auto edbTerm = Atom::Tabled("EDB");
 
    // send one negative answer if no positive answer was found
    auto negativeAnswer = std::make_shared<AnswerNo>();
    negativeAnswer->setReasonerTerm(edbTerm);
    // Apply query context "origin" and "perspective" to the answer if any
    negativeAnswer->applyFrame(q->ctx()->selector);
    // the answer is uncertain as we only were not able to obtain a positive answer
    // which does not mean that there is no positive answer.
    negativeAnswer->setIsUncertain(true, std::nullopt);
 
    // Add ungrounded literals to negative answer.
    // But at the moment the information is not provided by EDBs, would be difficult to implement e.g. in MongoDB.
    // Well at least we know if the query is only a single triple pattern.
    if (q->path().size() == 1) {
        negativeAnswer->addUngrounded(q->path().front()->predicate(),
                                      q->path().front()->isNegated());
    }
    return negativeAnswer;
}

no() [2/2]

static std::shared_ptr<AnswerNo> knowrob::QueryableStorage::no ( const GraphPathQueryPtr &  q )

static

Generates a negative answer to a query.

Parameters

q	a graph path query.

Returns

a negative answer to the query.

query() [1/2]

virtual void knowrob::QueryableStorage::query ( const GraphQueryPtr &  query, const BindingsHandler &  callback  )

pure virtual

Submits a graph query to this storage.

Parameters

query	a graph query
callback	a function that is called for each answer to the query.

Implemented in knowrob::SPARQLBackend, knowrob::MongoKnowledgeGraph, knowrob::PrologBackend, knowrob::SPARQLBackend, knowrob::MongoKnowledgeGraph, and knowrob::PrologBackend.

query() [2/2]

virtual void knowrob::QueryableStorage::query ( const GraphQueryPtr &  query, const BindingsHandler &  callback  )

pure virtual

Submits a graph query to this storage.

Parameters

query	a graph query
callback	a function that is called for each answer to the query.

Implemented in knowrob::SPARQLBackend, knowrob::MongoKnowledgeGraph, knowrob::PrologBackend, knowrob::SPARQLBackend, knowrob::MongoKnowledgeGraph, and knowrob::PrologBackend.

setVersionOfOrigin() [1/2]

void QueryableStorage::setVersionOfOrigin	(	std::string_view	origin,
		std::string_view	version
	)

Set the version of an origin.

Parameters

origin	an origin string.
version	a version string.

Definition at line 36 of file QueryableStorage.cpp.

                                                                                       {
    TripleView triple;
    triple.setSubject(origin);
    triple.setPredicate(versionProperty->stringForm());
    triple.setStringValue(version);
    triple.setGraph(origin);
    insertOne(triple);
}

setVersionOfOrigin() [2/2]

void knowrob::QueryableStorage::setVersionOfOrigin	(	std::string_view	origin,
		std::string_view	version
	)

Set the version of an origin.

Parameters

origin	an origin string.
version	a version string.

yes() [1/2]

std::shared_ptr< AnswerYes > QueryableStorage::yes ( const GraphPathQueryPtr &  original, const GraphQueryExpansionPtr &  expansion, const BindingsPtr &  bindings  )

static

Generates a positive answer to a query.

Parameters

original	a graph path query.
expansion	a graph query expansion.
bindings	a set of bindings.

Returns

a positive answer to the query.

Definition at line 100 of file QueryableStorage.cpp.

                                                                              {
    static const auto edbTerm = Atom::Tabled("EDB");
 
    auto positiveAnswer = std::make_shared<AnswerYes>(bindings);
    // Indicate that EDB has computed the grounding.
    positiveAnswer->setReasonerTerm(edbTerm);
    // Apply query context to the answer for some parameters.
    positiveAnswer->applyFrame(original->ctx()->selector);
 
    // Add predicate groundings to the answer
    for (auto &rdfLiteral: original->path()) {
        auto p = rdfLiteral->predicate();
        auto p_instance = applyBindings(p, *positiveAnswer->substitution());
        positiveAnswer->addGrounding(
                std::static_pointer_cast<Predicate>(p_instance),
                rdfLiteral->isNegated(),
                positiveAnswer->frame());
    }
 
    // The answer is uncertain if any of the groundings is uncertain.
    positiveAnswer->setIsUncertain(
            std::any_of(expanded->u_vars.begin(), expanded->u_vars.end(), [&](const VariablePtr &v) {
                auto &u_v = bindings->get(v->name());
                return (u_v && u_v->isNumeric() && std::static_pointer_cast<Numeric>(u_v)->asBoolean());
            }), std::nullopt);
 
    // The answer is occasional if any of the groundings has occasional=true flag
    positiveAnswer->setIsOccasionallyTrue(
            std::any_of(expanded->o_vars.begin(), expanded->o_vars.end(), [&](const VariablePtr &v) {
                auto &o_v = bindings->get(v->name());
                return (o_v && o_v->isNumeric() && std::static_pointer_cast<Numeric>(o_v)->asBoolean());
            }));
 
    return positiveAnswer;
}

yes() [2/2]

static std::shared_ptr<AnswerYes> knowrob::QueryableStorage::yes ( const GraphPathQueryPtr &  original, const GraphQueryExpansionPtr &  expansion, const BindingsPtr &  bindings  )

static

Generates a positive answer to a query.

Parameters

original	a graph path query.
expansion	a graph query expansion.
bindings	a set of bindings.

Returns

a positive answer to the query.

Member Data Documentation

versionProperty

AtomPtr QueryableStorage::versionProperty = IRIAtom::Tabled("http://knowrob.org/kb/knowrob.owl#hasVersionOfOrigin")

static

Definition at line 29 of file QueryableStorage.h.

---

The documentation for this class was generated from the following files:

• build/_CPack_Packages/Linux/DEB/knowrob-2.1.0-Linux/usr/include/knowrob/storage/QueryableStorage.h
• src/storage/QueryableStorage.cpp