[
https://issues.apache.org/jira/browse/HADOOP-15033?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16296837#comment-16296837
]
ASF GitHub Bot commented on HADOOP-15033:
-----------------------------------------
Github user dchuyko commented on a diff in the pull request:
https://github.com/apache/hadoop/pull/291#discussion_r157763230
--- Diff:
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/DataChecksum.java
---
@@ -78,6 +100,16 @@ public static Checksum newCrc32() {
return new CRC32();
}
+ public static Checksum newCrc32C() {
+ try {
+ return Shell.isJava9OrAbove() ? (Checksum) NEW_CRC32C_MH.invoke()
+ : new PureJavaCrc32C();
+ } catch (Throwable e) {
+ // Should not reach here.
+ throw new RuntimeException(e);
--- End diff --
Got it, this will be more clean.
> Use java.util.zip.CRC32C for Java 9 and above
> ---------------------------------------------
>
> Key: HADOOP-15033
> URL: https://issues.apache.org/jira/browse/HADOOP-15033
> Project: Hadoop Common
> Issue Type: Improvement
> Components: performance, util
> Affects Versions: 3.0.0
> Reporter: Dmitry Chuyko
> Labels: Java9, common, jdk9
> Attachments: HADOOP-15033.001.patch, HADOOP-15033.001.patch,
> HADOOP-15033.002.patch, HADOOP-15033.003.patch, HADOOP-15033.003.patch,
> HADOOP-15033.004.patch
>
>
> java.util.zip.CRC32C implementation is available since Java 9.
> https://docs.oracle.com/javase/9/docs/api/java/util/zip/CRC32C.html
> Platform specific assembler intrinsics make it more effective than any pure
> Java implementation.
> Hadoop is compiled against Java 8 but class constructor may be accessible
> with method handle on 9 to instances implementing Checksum in runtime.
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
