BGPStageBuilder | sparql-engine

A BGPStageBuilder evaluates Basic Graph Patterns in a SPARQL query. Users can extend this class and overrides the "_buildIterator" method to customize BGP evaluation.

author: Thomas Minier
author: Corentin Marionneau

Hierarchy

StageBuilder
- BGPStageBuilder

Index

Constructors

constructor

Properties

Accessors

Methods

Constructors

constructor

new BGPStageBuilder(_dataset: Dataset): BGPStageBuilder

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

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

_buildFullTextSearchIterator

_buildFullTextSearchIterator(source: PipelineStage<Bindings>, graph: Graph, pattern: TripleObject, queryVariable: string, magicTriples: TripleObject[], context: ExecutionContext): PipelineStage<Bindings>

- Defined in src/engine/stages/bgp-stage-builder.ts:203
Returns a PipelineStage used to evaluate a Full Text Search query from a set of magic patterns.

Parameters
- source: PipelineStage<Bindings>
  
  Input PipelineStage
- graph: Graph
  
  The graph on which the full text search should be executed
- pattern: TripleObject
  
  Input triple pattern
- queryVariable: string
  
  SPARQL variable on which the full text search is performed
- magicTriples: TripleObject[]
  
  Set of magic triple patterns used to configure the full text search
- context: ExecutionContext
  
  Execution options
Returns PipelineStage<Bindings>

A PipelineStage used to evaluate the Full Text Search query

_buildIterator

_buildIterator(source: PipelineStage<Bindings>, graph: Graph, patterns: TripleObject[], context: ExecutionContext): PipelineStage<Bindings>

- Defined in src/engine/stages/bgp-stage-builder.ts:186
Returns a PipelineStage used to evaluate a Basic Graph pattern

Parameters
- source: PipelineStage<Bindings>
  
  Input PipelineStage
- graph: Graph
  
  The graph on which the BGP should be executed
- patterns: TripleObject[]
  
  Set of triple patterns
- context: ExecutionContext
  
  Execution options
Returns PipelineStage<Bindings>

A PipelineStage used to evaluate a Basic Graph pattern

_getGraph

_getGraph(iris: string[]): Graph

- Defined in src/engine/stages/bgp-stage-builder.ts:83
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

_replaceBlankNodes

_replaceBlankNodes(patterns: TripleObject[]): [TripleObject[], string[]]

- Defined in src/engine/stages/bgp-stage-builder.ts:156
Replace the blank nodes in a BGP by SPARQL variables

Parameters
- patterns: TripleObject[]
  
  BGP to rewrite, i.e., a set of triple patterns
Returns [TripleObject[], string[]]

A Tuple [Rewritten BGP, List of SPARQL variable added]

execute

execute(source: PipelineStage<Bindings>, patterns: TripleObject[], context: ExecutionContext): PipelineStage<Bindings>

Overrides StageBuilder.execute
- Defined in src/engine/stages/bgp-stage-builder.ts:99
Build a PipelineStage to evaluate a BGP

Parameters
- source: PipelineStage<Bindings>
  
  Input PipelineStage
- patterns: TripleObject[]
  
  Set of triple patterns
- context: ExecutionContext
Returns PipelineStage<Bindings>

A PipelineStage used to evaluate a Basic Graph pattern

Hierarchy

Index

Constructors

Properties

Accessors

Methods

Constructors

constructor

Parameters

_dataset: Dataset

Returns BGPStageBuilder

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

_buildFullTextSearchIterator

Parameters

source: PipelineStage<Bindings>

graph: Graph

pattern: TripleObject

queryVariable: string

magicTriples: TripleObject[]

context: ExecutionContext

Returns PipelineStage<Bindings>

_buildIterator

Parameters

source: PipelineStage<Bindings>

graph: Graph

patterns: TripleObject[]

context: ExecutionContext

Returns PipelineStage<Bindings>

_getGraph

Parameters

iris: string[]

Returns Graph

_replaceBlankNodes

Parameters

patterns: TripleObject[]

Returns [TripleObject[], string[]]

execute

Parameters

source: PipelineStage<Bindings>

patterns: TripleObject[]

context: ExecutionContext

Returns PipelineStage<Bindings>