Package com.singularsys.jep.misc.parallelparsing

Class ConcurrentVariableTable

java.lang.Object
com.singularsys.jep.VariableTable
com.singularsys.jep.misc.parallelparsing.ConcurrentVariableTable
All Implemented Interfaces:
JepComponent, Serializable
public class ConcurrentVariableTable extends VariableTable
A variable table backed by a ConcurrentHashMap that is safe for concurrent access. Inside the addVariable(String) methods it uses the ConcurrentHashMap.computeIfAbsent(Object, java.util.function.Function) and ConcurrentHashMap.compute(Object, java.util.function.BiFunction) to atomically create variables when needed. As a consequence, the addVariable(String) methods may block while a variable is created in another thread.
See Also:

  • Constructor Details

    • ConcurrentVariableTable

      public ConcurrentVariableTable()
      Default constructor.

    • ConcurrentVariableTable

      public ConcurrentVariableTable(VariableTable tbl)
      Copy constructor, For each variable from the source table create a new variable.
      Parameters:
      tbl - source table

  • Method Details

    • init

      public void init(Jep j)
      Description copied from interface: JepComponent
      Initialize the component. This method is called whenever a component is added to Jep. Hence, it allows components to keep track of the other components they may rely on.
      Specified by:
      init in interface JepComponent
      Overrides:
      init in class VariableTable
      Parameters:
      j - the current Jep instance

    • addVariable

      public Variable addVariable(String name)
      Description copied from class: VariableTable
      Adds a new variable with no value specified. If the variable already exists in the table, that variable instance is returned. Otherwise, a new Variable instance is created with the variable factory.
      Overrides:
      addVariable in class VariableTable
      Parameters:
      name - the variable's name
      Returns:
      the variable

    • addVariable

      public Variable addVariable(String name, Object value) throws JepException
      Description copied from class: VariableTable
      Adds a new variable with specified value. If the variable already exists, its value is updated with the new value. If the variable exists and is a constant, the value is not updated and no error is reported. If the variable does not exist, it is created using the variable factory of the jep instance specified with the init(Jep j) method.
      Overrides:
      addVariable in class VariableTable
      Parameters:
      name - the name of the variable
      value - the value for the variable to be set to
      Returns:
      the variable added or updated
      Throws:
      JepException - if an attempt is made to set the value of a constant variable

    • addConstant

      public Variable addConstant(String name, Object value) throws JepException
      Description copied from class: VariableTable
      Adds a new variable which is marked as a constant. Its value will also be marked as valid, in particular a null value is valid for a constant.
      Overrides:
      addConstant in class VariableTable
      Parameters:
      name - variable name
      value - variable value
      Returns:
      the corresponding Variable object
      Throws:
      JepException - if an attempt is made to set the value of an existing constant variable

    • getVariable

      public Variable getVariable(String name)
      Description copied from class: VariableTable
      Gets an existing variable, returns null if variable is not found.
      Overrides:
      getVariable in class VariableTable
      Parameters:
      name - variable name
      Returns:
      the variable

    • clear

      public void clear()
      Description copied from class: VariableTable
      Clears all variables from the table.
      Overrides:
      clear in class VariableTable

    • isEmpty

      public boolean isEmpty()
      Description copied from class: VariableTable
      Returns true if the table is empty.
      Overrides:
      isEmpty in class VariableTable
      Returns:
      true if the table is empty

    • keySet

      public Set<String> keySet()
      Description copied from class: VariableTable
      Returns the names of all the variables.
      Overrides:
      keySet in class VariableTable
      Returns:
      a collection Strings with the variable names.

    • getVariables

      public Collection<Variable> getVariables()
      Description copied from class: VariableTable
      Returns a list of all the variables in the table. Just returns a view. Does not do a deep copy so changes to this collection will affect the underlying table.
      Overrides:
      getVariables in class VariableTable
      Returns:
      a collection of all the variables.

    • remove

      public Variable remove(String varname)
      Description copied from class: VariableTable
      Remove a variable with a given name from the table.
      Overrides:
      remove in class VariableTable
      Parameters:
      varname - name of the variable to remove
      Returns:
      the removed variable or null if the variable does not exist in the table.

    • remove

      public Variable remove(Variable var)
      Description copied from class: VariableTable
      Remove a variable from the table.
      Overrides:
      remove in class VariableTable
      Parameters:
      var - the variable to remove
      Returns:
      the removed variable or null if the variable does not exist in the table.

    • values

      @Deprecated public Collection<Variable> values()
      Deprecated.
      use getVariables().
      A collection of all the variables. Replace with getVariables()
      Overrides:
      values in class VariableTable
      Returns:
      a collection of all the variables.

    • size

      public int size()
      Description copied from class: VariableTable
      The number of variables in the table.
      Overrides:
      size in class VariableTable
      Returns:
      the number of variables

    • containsKey

      public boolean containsKey(String key)
      Description copied from class: VariableTable
      Returns true if the table contains a variable with the given name.
      Overrides:
      containsKey in class VariableTable
      Parameters:
      key - variable name
      Returns:
      true if the table contains the variable

    • containsVariable

      public boolean containsVariable(Variable value)
      Description copied from class: VariableTable
      Returns true if the table contains the given variable.
      Overrides:
      containsVariable in class VariableTable
      Parameters:
      value - the variable
      Returns:
      true if the variable is in the table

    • getLightWeightInstance

      public JepComponent getLightWeightInstance()
      Description copied from class: VariableTable
      Returns a new empty VariableTable.
      Specified by:
      getLightWeightInstance in interface JepComponent
      Overrides:
      getLightWeightInstance in class VariableTable
      Returns:
      a new VariableTable
      See Also:

    • clearValues

      public void clearValues()
      Description copied from class: VariableTable
      Clears the values of all non-constant variables. This will set the Variable.setValidValue(boolean) to false.
      Overrides:
      clearValues in class VariableTable

    • removeNonConstants

      public void removeNonConstants()
      Description copied from class: VariableTable
      Remove all variables from the table which are not constants.
      Overrides:
      removeNonConstants in class VariableTable