My two cents... :)
Put all the array size checking code in one place is a good idea. Code
reuse is always good idea.
But do not forget that Java has 2 problems here:
1. It can not inline methods or include code in java file
2. Method call is a long operation.
So huge number of additional method calls can significantly downgrade
the performance...
Probably VM JIT guys will correct me.
Anyway... I think that the best plays for such tool methods is a misc
module, not util.
SY, Alexey
2006/7/21, Andrew Zhang <[EMAIL PROTECTED]>:
Hi Vladimir,
I noticed the same problem is existing in many places of NIO module.
How about writing a utility function for array index exception check? like:
void assertArrayIndex(Object[] array, int offset, int length){
if(offset < 0 || length < 0 || (long)offset + (long)length > array.length
){
throw new IndexOutOfBoundsException();
}
}
How do you think about it? Any suggestions?
Thanks!
Best regards,
On 7/21/06, Paulex Yang (JIRA) <[EMAIL PROTECTED]> wrote:
>
> [ http://issues.apache.org/jira/browse/HARMONY-932?page=all ]
>
> Paulex Yang closed HARMONY-932.
> -------------------------------
>
> Estimated Complexity: Novice
>
> Verified by Vladimir.
>
> > [classlib][nio]java.nio.?hannel.DatagramChannel.read(ByteBuffer[] , int,
> Integer.MAX_VALUE) throws NotYetConnectedException while RI throws
> IndexOutOfBoundsException
> >
>
---------------------------------------------------------------------------------------------------------------------------------------------------------------------
> >
> > Key: HARMONY-932
> > URL: http://issues.apache.org/jira/browse/HARMONY-932
> > Project: Harmony
> > Issue Type: Bug
> > Components: Classlib
> > Reporter: Vladimir Ivanov
> > Assigned To: Paulex Yang
> > Attachments: DatagramChannelImpl.patch
> >
> >
> > The Harmony methods java.nio.?hannel.DatagramChannel.read/write(ByteBuffer[]
> , int, Integer.MAX_VALUE) throws NotYetConnectedException while RI throws
> IndexOutOfBoundsException.
> > ==================== test.java ======================
> > import java.nio.channels.*;
> > import java.nio.*;
> > public class test {
> > public static void main (String[] args) {
> > try {
> > DatagramChannel.open().read(new ByteBuffer[] {}, 2,
> Integer.MAX_VALUE);
> > } catch (Exception e) {
> > e.printStackTrace();
> > }
> > try {
> > DatagramChannel.open().write(new ByteBuffer[] {}, 2,
> Integer.MAX_VALUE);
> > } catch (Exception e) {
> > e.printStackTrace();
> > }
> > }
> > }
> > =================================================
> > Output:
> > C:\tmp\tmp17>C:\jdk1.5.0_06\bin\java.exe -cp . -showversion test
> > java version "1.5.0_06"
> > Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_06-b05)
> > Java HotSpot(TM) Client VM (build 1.5.0_06-b05, mixed mode)
> > java.lang.IndexOutOfBoundsException
> > at sun.nio.ch.DatagramChannelImpl.read(DatagramChannelImpl.java
> :366)
> > at test.main(test.java:8)
> > java.lang.IndexOutOfBoundsException
> > at sun.nio.ch.DatagramChannelImpl.write(DatagramChannelImpl.java
> :429)
> > at test.main(test.java:13)
> > C:\tmp\tmp17>C:\jrockit-jdk1.5.0-windows-ia32\bin\java.exe -cp .
> -showversion test
> > java version "1.5.0"
> > Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0-b64)
> > BEA WebLogic JRockit(R) (build dra-38972-20041208-2001-win-ia32,
> R25.0.0-75, GC: System optimized over throughput (initial strategy
> singleparpar))
> > OutOfMemoryError
> > -------end of stacktrace
> > C:\tmp\tmp17>C:\harmony\trunk_0427\deploy\jdk\jre\bin\java.exe -cp .
> -showversion test
> > java version 1.5 (subset)
> > (c) Copyright 1991, 2006 The Apache Software Foundation or its
> licensors, as applicable.
> > java.nio.channels.NotYetConnectedException
> > at
> org.apache.harmony.nio.internal.DatagramChannelImpl.checkOpenConnected(
> DatagramChannelImpl.java:567)
> > at org.apache.harmony.nio.internal.DatagramChannelImpl.read(
> DatagramChannelImpl.java:387)
> > at test.main(test.java:8)
> > java.nio.channels.NotYetConnectedException
> > at
> org.apache.harmony.nio.internal.DatagramChannelImpl.checkOpenConnected(
> DatagramChannelImpl.java:567)
> > at org.apache.harmony.nio.internal.DatagramChannelImpl.write(
> DatagramChannelImpl.java:477)
> > at test.main(test.java:13)
> >
>
C:\tmp\tmp17>C:\harmony\drlvm\trunk\build\win_ia32_msvc_debug\deploy\jre\bin\ij
> -Dvm.assert_dialog=false -cp . -showversion test
> > Apache Harmony DRLVM HEAD-4807 (2006-05-02), Windows/ia32/msvc 1310,
> debug
> > java.nio.channels.NotYetConnectedException
> > at
> org.apache.harmony.nio.internal.DatagramChannelImpl.checkOpenConnected(
> DatagramChannelImpl.java:567)
> > at org.apache.harmony.nio.internal.DatagramChannelImpl.read(
> DatagramChannelImpl.java:387)
> > at test.main(test.java:8)
> > java.nio.channels.NotYetConnectedException
> > at
> org.apache.harmony.nio.internal.DatagramChannelImpl.checkOpenConnected(
> DatagramChannelImpl.java:567)
> > at org.apache.harmony.nio.internal.DatagramChannelImpl.write(
> DatagramChannelImpl.java:477)
> > at test.main(test.java:13)
>
> --
> This message is automatically generated by JIRA.
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>
>
>
--
Andrew Zhang
China Software Development Lab, IBM
--
Alexey A. Petrenko
Intel Middleware Products Division
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