[LANG-523] StrBuilder is slow

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.4
• Fix Version/s: 2.5
• Component/s: lang.text.*
• Assignee: Unassigned
• Reporter: Stefan Zeller
• Created: 21/Aug/09 12:09
• Updated: 25/Feb/10 19:51
• Resolved: 06/Sep/09 22:56

Description

I need a faster StringBuffer for java 1.4 branch.

So I tested StrBuffer. The result is not sufficient as it is 500 times slower than StringBuffer. The problem is that currently the StrBuilder increases the buffer size by the length of the string that thought to be appended.

Changing this strategy to provide the double of the needed buffer size brings the performance near to the StringBuilder.

Here the times (the average of four runs in ms) for the Testcase attached. Where MyStrBuilder is the pathed version of StrBuilder

startStringBuffer: 105.25
startStrBuilder: 5863.75
startStringBuilder: 55
startMyStringBuilder: 54