Multiple replace function call can be replaced with a single for loop to
improve performance
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Key: CHUKWA-584
URL: https://issues.apache.org/jira/browse/CHUKWA-584
Project: Chukwa
Issue Type: Bug
Components: data collection
Affects Versions: 0.4.0
Reporter: Xiaoming Shi
{noformat}
./chukwa-0.4.0/src/java/org/apache/hadoop/chukwa/datacollection/writer/SeqFileWriter.java
line: 179
./chukwa-0.4.0/src/java/org/apache/hadoop/chukwa/datacollection/writer/localfs/LocalWriter.java
line:285
{noformat}
3 consecutive replace() is called to remove the special characters. It's 3+
times slower than using a for loop
replace them all.
{noformat}
e.g.
- str.replace('a', '#');
- str.replace('b', '%');
+ StringBuilder sb = new StringBuilder( str.length() );
+ for (int i=0; i < str.length(); i++)
+ {
+ char c = str.charAt(i);
+ if ( c == 'a' )
+ sb.append('#');
+ else if ( c== 'b' )
+ sb.append('%');
+ else
+ sb.append(c);
+ }
+ str = sb.toString();
{noformat}
This bug has the same problem as the MySQL bug :
http://bugs.mysql.com/bug.php?id=45699
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