Module org.elasticsearch.server
Package org.elasticsearch.script

Class ScriptContext<FactoryType>

java.lang.Object
org.elasticsearch.script.ScriptContext<FactoryType>
public final class ScriptContext<FactoryType> extends Object
The information necessary to compile and run a script. A ScriptContext contains the information related to a single use case and the interfaces and methods necessary for a ScriptEngine to implement.

There are at least two (and optionally a third) related classes which must be defined.

The InstanceType is a class which users of the script api call to execute a script. It may be stateful. Instances of the InstanceType may be executed multiple times by a caller with different arguments. This class must have an abstract method named execute which ScriptEngine implementations will define.

The FactoryType is a factory class returned by the ScriptService when compiling a script. This class must be stateless so it is cacheable by the ScriptService. It must have one of the following:

  • An abstract method named newInstance which returns an instance of InstanceType
  • An abstract method named newFactory which returns an instance of StatefulFactoryType

The StatefulFactoryType is an optional class which allows a stateful factory from the stateless factory type required by the ScriptService. If defined, the StatefulFactoryType must have a method named newInstance which returns an instance of InstanceType.

Both the FactoryType and StatefulFactoryType may have abstract methods to indicate whether a variable is used in a script. These method should return a boolean and their name should start with needs, followed by the variable name, with the first letter uppercased. For example, to check if a variable doc is used, a method boolean needsDoc() should be added. If the variable name starts with an underscore, for example, _score, the needs method would be boolean needs_score().

  • Field Details

    • DEFAULT_COMPILATION_RATE_LIMIT

      public static final Tuple<Integer,TimeValue> DEFAULT_COMPILATION_RATE_LIMIT
      The default compilation rate limit for contexts with compilation rate limiting enabled

    • name

      public final String name
      A unique identifier for this context.

    • factoryClazz

      public final Class<FactoryType> factoryClazz
      A factory class for constructing script or stateful factory instances.

    • statefulFactoryClazz

      public final Class<?> statefulFactoryClazz
      A factory class for construct script instances.

    • instanceClazz

      public final Class<?> instanceClazz
      A class that is an instance of a script.

    • cacheSizeDefault

      public final int cacheSizeDefault
      The default size of the cache for the context if not overridden

    • cacheExpireDefault

      public final TimeValue cacheExpireDefault
      The default expiration of a script in the cache for the context, if not overridden

    • compilationRateLimited

      public final boolean compilationRateLimited
      Is compilation rate limiting enabled for this context?

    • allowStoredScript

      public final boolean allowStoredScript
      Determines if the script can be stored as part of the cluster state.

  • Constructor Details

    • ScriptContext

      public ScriptContext(String name, Class<FactoryType> factoryClazz, int cacheSizeDefault, TimeValue cacheExpireDefault, boolean compilationRateLimited, boolean allowStoredScript)
      Construct a context with the related instance and compiled classes with caller provided cache defaults

    • ScriptContext

      public ScriptContext(String name, Class<FactoryType> factoryClazz)
      Construct a context with the related instance and compiled classes with defaults for cacheSizeDefault, cacheExpireDefault and compilationRateLimited and allow scripts of this context to be stored scripts