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HDFS-15384. Document getLocatedBlocks(String src, long start) of DFSClient only return partial blocks. Contributed by Yang Yun.

This commit is contained in:
He Xiaoqiao 2021-03-08 12:18:46 +08:00
parent 9cb51bf106
commit 4a0b7f7ebe
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hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DFSClient.java
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@ -861,6 +861,18 @@ public class DFSClient implements java.io.Closeable, RemotePeerFactory,
return dfsClientConf.getRefreshReadBlockLocationsMS();
}
/**
* Get locations of the blocks of the specified file `src` from offset
* `start` within the prefetch size which is related to parameter
* `dfs.client.read.prefetch.size`. DataNode locations for each block are
* sorted by the proximity to the client. Please note that the prefetch size
* is not equal file length generally.
*
* @param src the file path.
* @param start starting offset.
* @return LocatedBlocks
* @throws IOException
*/
public LocatedBlocks getLocatedBlocks(String src, long start)
throws IOException {
return getLocatedBlocks(src, start, dfsClientConf.getPrefetchSize());