hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Colin Patrick McCabe (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HDFS-5450) better API for getting the cached blocks locations
Date Mon, 11 Nov 2013 18:29:19 GMT

    [ https://issues.apache.org/jira/browse/HDFS-5450?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13819181#comment-13819181
] 

Colin Patrick McCabe commented on HDFS-5450:
--------------------------------------------

Looks like a good cleanup.  I like the idea of using a shared empty array rather than having
"if null" sprinkled everywhere.

{code}
   /**
+   * Set the hosts hosting a cached replica of this block
+   */
+  public void setCachedHosts(String[] cachedHosts) {
+    if (cachedHosts != null) {
+      this.cachedHosts = cachedHosts;
+    }
+  }
+
+  /**
    * Set the names (host:port) hosting this block
    */
   public void setNames(String[] names) throws IOException {
-    if (names == null) {
-      this.names = new String[0];
-    } else {
+    if (names != null) {
       this.names = names;
     }
   }
@@ -197,9 +222,7 @@ public void setNames(String[] names) throws IOException {
    * Set the network topology paths of the hosts
    */
   public void setTopologyPaths(String[] topologyPaths) throws IOException {
-    if (topologyPaths == null) {
-      this.topologyPaths = new String[0];
-    } else {
+    if (topologyPaths != null) {
       this.topologyPaths = topologyPaths;
     }
   }
{code}

This doesn't seem quite right.  If someone sets one of these things to null, surely we should
interpret that as clearing the field, rather than ignoring it altogether?

> better API for getting the cached blocks locations
> --------------------------------------------------
>
>                 Key: HDFS-5450
>                 URL: https://issues.apache.org/jira/browse/HDFS-5450
>             Project: Hadoop HDFS
>          Issue Type: Sub-task
>          Components: hdfs-client
>    Affects Versions: 3.0.0
>            Reporter: Colin Patrick McCabe
>            Assignee: Andrew Wang
>            Priority: Minor
>         Attachments: hdfs-5450-1.patch, hdfs-5450-2.patch
>
>
> Currently, we have to downcast the {{BlockLocation}] to {{HdfsBlockLocation}} to get
information about whether a replica is cached.  We should have this information in {{BlockLocation}}
instead.



--
This message was sent by Atlassian JIRA
(v6.1#6144)

Mime
View raw message