Satendra Kumar created KAFKA-3768:
-------------------------------------
Summary: 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: Bug
Reporter: Satendra Kumar
Priority: Minor
Scala recommend use if/else clock instead of pattern match on boolean values.
For example:
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"
}
}
}
Byte code comparison between method1 and method2:
scala>javap -cp Comparasion
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
}
method1 have 23 line of byte code and 6 line byte code. Pattern match are more
expensive comparison to if/else block.
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