Steve Lawrence created DAFFODIL-1933:
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Summary: Performance regression with new Base64/Layering changes
Key: DAFFODIL-1933
URL: https://issues.apache.org/jira/browse/DAFFODIL-1933
Project: Daffodil
Issue Type: Bug
Components: Back End
Reporter: Steve Lawrence
Assignee: Michael Beckerle
Fix For: 2.2.0
Nightly tests showed a fairly drastic performance regression (50% reduction in
speed) in commit 1ea2290f28: All properties for Base64/layering implemented.
Skimming the code, one change jumped out at me as a likely cause in
ByteBufferDataInputStream.scala:
{code:language=diff}
@@ -91,7 +90,13 @@ object ByteBufferDataInputStream {
case _ => {
// copy the contents of the stream into an array of bytes
val bos = new ByteArrayOutputStream
- IOUtils.copy(in, bos)
+ var b: Int = 0
+ while ({
+ b = in.read()
+ b != -1
+ }) {
+ bos.write(b)
+ }
bos.flush()
bos.close()
in.close()
{code}
This changes the copy from a bulk copy to a byte-by-byte copy, which appears to
have pretty drastic performance. A few simple quick tests shows that reverting
this change recovers all performance losses.
Mike, can you confirm if this change can be reverted, or if there was some
other reason related to layering to switch to a byte-by-byte copy?
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