org.apache.calcite.runtime

Enum Hook

java.lang.Object

java.lang.Enum<Hook>

org.apache.calcite.runtime.Hook

All Implemented Interfaces:

Serializable, Comparable<Hook>

public enum Hook
extends Enum<Hook>

Collection of hooks that can be set by observers and are executed at various parts of the query preparation process.

For testing and debugging rather than for end-users.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	Hook.Closeable Removes a Hook after use.

Enum Constant Summary

Enum Constants

Enum Constant and Description
CONVERTED Called with the output of sql-to-rel-converter.
CREATE_MATERIALIZATION Called when materialization is created.
CURRENT_TIME Called to get the current time.
EXPRESSION_REDUCER Called when a constant expression is being reduced.
JAVA_PLAN Called with the generated Java plan, just before it is compiled by Janino.
PARSE_TREE Called with the SQL string and parse tree, in an array.
PROGRAM Called to create a Program to optimize the statement.
QUERY_PLAN Called with a query that has been generated to send to a back-end system.
SUB Called by the planner after substituting a materialization.
TRIMMED Called after de-correlation and field trimming, but before optimization.

Method Summary

Methods

Modifier and Type	Method and Description
<T,R> Hook.Closeable	add(com.google.common.base.Function<T,R> handler) Adds a handler for this Hook.
<T,R> Hook.Closeable	addThread(com.google.common.base.Function<T,R> handler) Adds a handler for this thread.
void	run(Object arg) Runs all handlers registered for this Hook, with the given argument.
static Hook	valueOf(String name) Returns the enum constant of this type with the specified name.
static Hook[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

CURRENT_TIME

public static final Hook CURRENT_TIME

Called to get the current time. Use this to return a predictable time in tests.

PARSE_TREE

public static final Hook PARSE_TREE

Called with the SQL string and parse tree, in an array.

JAVA_PLAN

public static final Hook JAVA_PLAN

Called with the generated Java plan, just before it is compiled by Janino.

CONVERTED

public static final Hook CONVERTED

Called with the output of sql-to-rel-converter.

TRIMMED

public static final Hook TRIMMED

Called after de-correlation and field trimming, but before optimization.

SUB

public static final Hook SUB

Called by the planner after substituting a materialization.

EXPRESSION_REDUCER

public static final Hook EXPRESSION_REDUCER

Called when a constant expression is being reduced.

PROGRAM

public static final Hook PROGRAM

Called to create a Program to optimize the statement.

CREATE_MATERIALIZATION

public static final Hook CREATE_MATERIALIZATION

Called when materialization is created.

QUERY_PLAN

public static final Hook QUERY_PLAN

Called with a query that has been generated to send to a back-end system. The query might be a SQL string (for the JDBC adapter), a list of Mongo pipeline expressions (for the MongoDB adapter), et cetera.

Method Detail

values

public static Hook[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (Hook c : Hook.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static Hook valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

add

public <T,R> Hook.Closeable add(com.google.common.base.Function<T,R> handler)

Adds a handler for this Hook.

Returns a Hook.Closeable so that you can use the following try-finally pattern to prevent leaks:

     final Hook.Closeable closeable = Hook.FOO.add(HANDLER);
     try {
         ...
     } finally {
         closeable.close();
     }

addThread

public <T,R> Hook.Closeable addThread(com.google.common.base.Function<T,R> handler)

Adds a handler for this thread.

run

public void run(Object arg)

Runs all handlers registered for this Hook, with the given argument.