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https://issues.apache.org/jira/browse/KAFKA-3768?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Ismael Juma resolved KAFKA-3768.
--------------------------------
Resolution: Fixed
Fix Version/s: 0.10.1.0
Issue resolved by pull request 1445
[https://github.com/apache/kafka/pull/1445]
> Replace all pattern match on boolean value by if/elase block.
> -------------------------------------------------------------
>
> Key: KAFKA-3768
> URL: https://issues.apache.org/jira/browse/KAFKA-3768
> Project: Kafka
> Issue Type: Improvement
> Reporter: Satendra Kumar
> Priority: Minor
> Fix For: 0.10.1.0
>
> Original Estimate: 1h
> Remaining Estimate: 1h
>
> Scala recommend use if/else block instead of pattern match on boolean
> values.
> For example:
> {code:title=Comparasion.scala|borderStyle=solid}
> class Comparasion {
> def method1(flag: Boolean): String = {
> flag match {
> case true => "TRUE"
> case false => "FALSE"
> }
> }
> def method2(flag: Boolean): String = {
> if(flag) {
> "TRUE"
> }else {
> "FALSE"
> }
> }
> }
> {code}
> Byte code comparison between method1 and method2:
> scala>javap -cp Comparasion
> {code:title=Comparasion.class|borderStyle=solid}
> Compiled from "<console>"
> public class Comparasion {
> public java.lang.String method1(boolean);
> Code:
> 0: iload_1
> 1: istore_2
> 2: iconst_1
> 3: iload_2
> 4: if_icmpne 13
> 7: ldc #9 // String TRUE
> 9: astore_3
> 10: goto 21
> 13: iconst_0
> 14: iload_2
> 15: if_icmpne 23
> 18: ldc #11 // String FALSE
> 20: astore_3
> 21: aload_3
> 22: areturn
> 23: new #13 // class scala/MatchError
> 26: dup
> 27: iload_2
> 28: invokestatic #19 // Method
> scala/runtime/BoxesRunTime.boxToBoolean:(Z)Ljava/lang/Boolean;
> 31: invokespecial #23 // Method
> scala/MatchError."<init>":(Ljava/lang/Object;)V
> 34: athrow
> public java.lang.String method2(boolean);
> Code:
> 0: iload_1
> 1: ifeq 9
> 4: ldc #9 // String TRUE
> 6: goto 11
> 9: ldc #11 // String FALSE
> 11: areturn
> public Comparasion();
> Code:
> 0: aload_0
> 1: invokespecial #33 // Method
> java/lang/Object."<init>":()V
> 4: return
> }
> {code}
> method1 have 23 line of byte code and method2 have only 6 line byte code.
> Pattern match are more expensive comparison to if/else block.
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