[CASSANDRA-2820] Re-introduce FastByteArrayInputStream (and Output equivalent)

• Type: Improvement
• Status: Resolved
• Priority: Low
• Resolution: Fixed
• Fix Version/s: 1.0.0
• Labels: bytearrayinputstream bytearrayoutputstream license synchronized

Environment

n/a

• Assignee: Paul Loy
• Reporter: Paul Loy

Authors

Paul Loy

Reviewers

Brandon Williams

• Created: 24/Jun/11 09:55
• Updated: 16/Apr/19 09:32
• Resolved: 16/Aug/11 18:27

Description

In https://issues.apache.org/jira/browse/CASSANDRA-37 FastByteArrayInputStream and FastByteArrayOutputStream were removed due to being code copied from the JDK and then subsequently modified. The JDK license is incompatible with Apache 2 license so the code had to go.

I have since had a look at the performance of the JDK ByteArrayInputStream and a FastByteArrayInputStream (i.e. one with synchronized methods made un-synchronized) and seen the difference is significant.

After a warmup-period of >10000 loops I get the following for 10000 loops through a 128000 byte array:

bais : 3513ms
fbais: 72ms

This varies depending on the OS, machine and Java version, but it's always in favour of the FastByteArrayInputStream as you might expect.

Then, at Jonathan Ellis' suggestion, I tried this using a modified Apache Harmony ByteArrayInputStream - i.e. one whose license is compatible - and the results were the same. A significant boost.

I will attach a patch with changes for the 0.8.0 tag.