Package tools.refinery.interpreter.matchers.backend

Class QueryEvaluationHint

java.lang.Object
tools.refinery.interpreter.matchers.backend.QueryEvaluationHint
public class QueryEvaluationHint extends Object
Provides Refinery Interpreter with additional hints on how a query should be evaluated. The same hint can be provided to multiple queries.

This class is immutable. Overriding options will create a new instance.

Here be dragons: for advanced users only.

  • Constructor Details

    • QueryEvaluationHint

      public QueryEvaluationHint(Map<QueryHintOption<?>,Object> backendHintSettings, QueryEvaluationHint.BackendRequirement backendRequirementType)
      Specifies the suggested query backend requirements, and value settings for additional backend-specific options.

      The backend requirement type must not be QueryEvaluationHint.BackendRequirement.SPECIFIC - for that case, use the constructor QueryEvaluationHint(Map, IQueryBackendFactory).

      Parameters:
      backendHintSettings - if non-null, each entry in the map overrides backend-specific options regarding query evaluation (null-valued map entries permitted to erase hints); passing null means default options associated with the query
      backendRequirementType - defines the kind of backend requirement
      Since:
      2.0

    • QueryEvaluationHint

      public QueryEvaluationHint(Map<QueryHintOption<?>,Object> backendHintSettings, IQueryBackendFactory queryBackendFactory)
      Specifies the suggested query backend, and value settings for additional backend-specific options. The first parameter can be null; if the second parameter is null, it is expected that the other constructor is called instead with a QueryEvaluationHint.BackendRequirement.UNSPECIFIED parameter.
      Parameters:
      backendHintSettings - if non-null, each entry in the map overrides backend-specific options regarding query evaluation (null-valued map entries permitted to erase hints); passing null means default options associated with the query
      queryBackendFactory - overrides the query evaluator algorithm; passing null retains the default algorithm associated with the query
      Since:
      1.5

  • Method Details

    • getQueryBackendRequirementType

      public QueryEvaluationHint.BackendRequirement getQueryBackendRequirementType()
      Returns the backend requirement described by this hint. If a specific backend is required, that can be queried by getQueryBackendFactory().
      Since:
      2.0

    • getQueryBackendFactory

      public IQueryBackendFactory getQueryBackendFactory()
      A suggestion for choosing the query evaluator algorithm.

      Returns null iff getQueryBackendRequirementType() does not return QueryEvaluationHint.BackendRequirement.SPECIFIC; in such cases a corresponding default backend is selected inside the engine

    • getBackendHintSettings

      public Map<QueryHintOption<?>,Object> getBackendHintSettings()
      Each entry in the immutable map overrides backend-specific options regarding query evaluation.

      The map is non-null, even if empty. Null-valued map entries are also permitted to erase hints via overrideBy(QueryEvaluationHint).

      Since:
      1.5

    • overrideBy

      public QueryEvaluationHint overrideBy(QueryEvaluationHint overridingHint)
      Override values in this hint and return a consolidated instance.
      Since:
      1.4

    • isOptionOverridden

      public boolean isOptionOverridden(QueryHintOption<?> option)
      Returns whether the given hint option is overridden.
      Since:
      1.5

    • getValueOrNull

      public <HintValue> HintValue getValueOrNull(QueryHintOption<HintValue> option)
      Returns the value of the given hint option from the given hint collection, or null if not defined.
      Since:
      1.5

    • getValueOrDefault

      public <HintValue> HintValue getValueOrDefault(QueryHintOption<HintValue> option)
      Returns the value of the given hint option from the given hint collection, or the default value if not defined. Intended to be called by backends to find out the definitive value that should be considered.
      Since:
      1.5

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • equals

      public boolean equals(Object obj)
      Overrides:
      equals in class Object

    • toString

      public String toString()
      Overrides:
      toString in class Object