Package org.apache.druid.segment.join

Class JoinPrefixUtils

java.lang.Object

org.apache.druid.segment.join.JoinPrefixUtils

public class JoinPrefixUtils
extends Object

Utility class for working with prefixes in join operations

Constructor Summary

Constructors

Constructor	Description
JoinPrefixUtils()

Method Summary

Modifier and Type	Method	Description
static void	checkPrefixesForDuplicatesAndShadowing(List<String> prefixes)	Check if any prefixes in the provided list duplicate or shadow each other.
static boolean	isPrefixedBy(String columnName, String prefix)
static String	unprefix(String columnName, String prefix)	Removes the prefix on columnName.
static String	validatePrefix(String prefix)	Checks that "prefix" is a valid prefix for a join clause (see JoinableClause.getPrefix()) and, if so, returns it.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

JoinPrefixUtils

public JoinPrefixUtils()

Method Details

validatePrefix

public static String validatePrefix(@Nullable
 String prefix)

Checks that "prefix" is a valid prefix for a join clause (see JoinableClause.getPrefix()) and, if so, returns it. Otherwise, throws an exception.

isPrefixedBy

public static boolean isPrefixedBy(String columnName,
 String prefix)

unprefix

public static String unprefix(String columnName,
 String prefix)

Removes the prefix on columnName. Must only be called if the column name is actually prefixed; i.e., if isPrefixedBy(String, String) would return true on the same arguments.

Throws:

IllegalArgumentException - if columnName does not start with prefix

checkPrefixesForDuplicatesAndShadowing

public static void checkPrefixesForDuplicatesAndShadowing(List<String> prefixes)

Check if any prefixes in the provided list duplicate or shadow each other.

Parameters:

prefixes - A mutable list containing the prefixes to check. This list will be sorted by descending string length.