GlushkovStageBuilder | sparql-engine

A GlushkovStageBuilder is responsible for evaluation a SPARQL property path query using a Glushkov state automata.

author: Arthur Trottier
author: Charlotte Cogan
author: Julien Aimonier-Davat

Hierarchy

PathStageBuilder
- GlushkovStageBuilder

Index

Constructors

constructor

Properties

Accessors

Methods

Constructors

constructor

new GlushkovStageBuilder(_dataset: Dataset): GlushkovStageBuilder

Inherited from StageBuilder.constructor
- Defined in src/engine/stages/stage-builder.ts:39
Parameters
- _dataset: Dataset
Returns GlushkovStageBuilder

Properties

Protected _builder

_builder: PlanBuilder | null = null

Protected _dataset

_dataset: Dataset

Accessors

builder

get builder(): PlanBuilder | null
set builder(builder: PlanBuilder | null): void

Inherited from StageBuilder.builder
- Defined in src/engine/stages/stage-builder.ts:43
Returns PlanBuilder | null
Inherited from StageBuilder.builder
- Defined in src/engine/stages/stage-builder.ts:47
Parameters
- builder: PlanBuilder | null
Returns void

dataset

get dataset(): Dataset
set dataset(dataset: Dataset): void

Inherited from StageBuilder.dataset
- Defined in src/engine/stages/stage-builder.ts:51
Returns Dataset
Inherited from StageBuilder.dataset
- Defined in src/engine/stages/stage-builder.ts:55
Parameters
- dataset: Dataset
Returns void

Methods

_buildIterator

_buildIterator(subject: string, path: PropertyPath, obj: string, context: ExecutionContext): PipelineStage<Bindings>

Inherited from PathStageBuilder._buildIterator
- Defined in src/engine/stages/path-stage-builder.ts:106
Get a PipelineStage for evaluating the property path.

Parameters
- subject: string
  
  Path subject
- path: PropertyPath
  
  Property path
- obj: string
  
  Path object
- context: ExecutionContext
  
  Execution context
Returns PipelineStage<Bindings>

A PipelineStage which yield set of bindings

_executePropertyPath

_executePropertyPath(subject: string, path: PropertyPath, obj: string, graph: Graph, context: ExecutionContext): PipelineStage<TripleObject>

Overrides PathStageBuilder._executePropertyPath
- Defined in src/engine/stages/glushkov-executor/glushkov-stage-builder.ts:317
Execute a property path against a RDF Graph.

Parameters
- subject: string
  
  Path subject
- path: PropertyPath
  
  Property path
- obj: string
  
  Path object
- graph: Graph
  
  RDF graph
- context: ExecutionContext
  
  Execution context
Returns PipelineStage<TripleObject>

An Observable which yield RDF triples matching the property path

_getGraph

_getGraph(iris: string[]): Graph

Inherited from PathStageBuilder._getGraph
- Defined in src/engine/stages/path-stage-builder.ts:71
Return the RDF Graph to be used for BGP evaluation.
- If iris is empty, returns the default graph
- If iris has a single entry, returns the corresponding named graph
- Otherwise, returns an UnionGraph based on the provided iris
Parameters
- iris: string[]
  
  List of Graph's iris
Returns Graph

An RDF Graph

evaluatePropertyPath

evaluatePropertyPath(rPath: ResultPath, obj: string, graph: Graph, context: ExecutionContext, automaton: Automaton<number, string>, forward: boolean): PipelineStage<TripleObject>

- Defined in src/engine/stages/glushkov-executor/glushkov-stage-builder.ts:169
Continues the execution of the SPARQL property path and builds the result's paths

Parameters
- rPath: ResultPath
  
  Path being processed
- obj: string
  
  Path object
- graph: Graph
  
  RDF graph
- context: ExecutionContext
  
  Execution context
- automaton: Automaton<number, string>
  
  Automaton used to evaluate the SPARQL property path
- forward: boolean
  
  if True the walk proceeds through outgoing edges, otherwise the walk proceeds in reverse direction
Returns PipelineStage<TripleObject>

An Observable which yield RDF triples matching the property path

execute

execute(source: PipelineStage<Bindings>, triples: PathTripleObject[], context: ExecutionContext): PipelineStage<Bindings>

Inherited from PathStageBuilder.execute

Overrides StageBuilder.execute
- Defined in src/engine/stages/path-stage-builder.ts:87
Get a PipelineStage for evaluating a succession of property paths, connected by joins.

Parameters
- source: PipelineStage<Bindings>
  
  Input PipelineStage
- triples: PathTripleObject[]
  
  Triple patterns
- context: ExecutionContext
  
  Execution context
Returns PipelineStage<Bindings>

A PipelineStage which yield set of bindings from the pipeline of joins

reflexiveClosure

reflexiveClosure(subject: string, obj: string, graph: Graph, context: ExecutionContext): PipelineStage<TripleObject>

- Defined in src/engine/stages/glushkov-executor/glushkov-stage-builder.ts:230
Execute a reflexive closure against a RDF Graph.

Parameters
- subject: string
  
  Path subject
- obj: string
  
  Path object
- graph: Graph
  
  RDF graph
- context: ExecutionContext
  
  Execution context
Returns PipelineStage<TripleObject>

An Observable which yield RDF triples retrieved after the evaluation of the reflexive closure

startPropertyPathEvaluation

startPropertyPathEvaluation(subject: string, obj: string, graph: Graph, context: ExecutionContext, automaton: Automaton<number, string>, forward: boolean): PipelineStage<TripleObject>

- Defined in src/engine/stages/glushkov-executor/glushkov-stage-builder.ts:268
Starts the execution of a property path against a RDF Graph.
- executes the reflexive closure if the path expression contains the empty word
- builds the first step of the result's paths
Parameters
- subject: string
  
  Path subject
- obj: string
  
  Path object
- graph: Graph
  
  RDF graph
- context: ExecutionContext
  
  Execution context
- automaton: Automaton<number, string>
  
  Automaton used to evaluate the SPARQL property path
- forward: boolean
  
  if True the walk starts from the subject, otherwise the walk starts from the object
Returns PipelineStage<TripleObject>

An Observable which yield RDF triples matching the property path

Hierarchy

Index

Constructors

Properties

Accessors

Methods

Constructors

constructor

Parameters

_dataset: Dataset

Returns GlushkovStageBuilder

Properties

Protected _builder

Protected _dataset

Accessors

builder

Returns PlanBuilder | null

Parameters

builder: PlanBuilder | null

Returns void

dataset

Returns Dataset

Parameters

dataset: Dataset

Returns void

Methods

_buildIterator

Parameters

subject: string

path: PropertyPath

obj: string

context: ExecutionContext

Returns PipelineStage<Bindings>

_executePropertyPath

Parameters

subject: string

path: PropertyPath

obj: string

graph: Graph

context: ExecutionContext

Returns PipelineStage<TripleObject>

_getGraph

Parameters

iris: string[]

Returns Graph

evaluatePropertyPath

Parameters

rPath: ResultPath

obj: string

graph: Graph

context: ExecutionContext

automaton: Automaton<number, string>

forward: boolean

Returns PipelineStage<TripleObject>

execute

Parameters

source: PipelineStage<Bindings>

triples: PathTripleObject[]

context: ExecutionContext

Returns PipelineStage<Bindings>

reflexiveClosure

Parameters

subject: string

obj: string

graph: Graph

context: ExecutionContext

Returns PipelineStage<TripleObject>

startPropertyPathEvaluation

Parameters

subject: string

obj: string

graph: Graph

context: ExecutionContext

automaton: Automaton<number, string>

forward: boolean

Returns PipelineStage<TripleObject>