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https://issues.apache.org/jira/browse/HADOOP-19389?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17914178#comment-17914178
]
ASF GitHub Bot commented on HADOOP-19389:
-----------------------------------------
cnauroth commented on code in PR #7291:
URL: https://github.com/apache/hadoop/pull/7291#discussion_r1920472066
##########
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/shell/Display.java:
##########
@@ -237,30 +237,69 @@ public TextRecordInputStream(FileStatus f) throws
IOException {
public int read() throws IOException {
int ret;
if (null == inbuf || -1 == (ret = inbuf.read())) {
- key = r.next(key);
- if (key == null) {
- return -1;
+ if (!readNextFromSequenceFile()) {
+ ret = -1;
} else {
- val = r.getCurrentValue(val);
+ ret = inbuf.read();
}
- byte[] tmp = key.toString().getBytes(StandardCharsets.UTF_8);
- outbuf.write(tmp, 0, tmp.length);
- outbuf.write('\t');
- tmp = val.toString().getBytes(StandardCharsets.UTF_8);
- outbuf.write(tmp, 0, tmp.length);
- outbuf.write('\n');
- inbuf.reset(outbuf.getData(), outbuf.getLength());
- outbuf.reset();
- ret = inbuf.read();
}
return ret;
}
+ @Override
+ public int read(byte[] dest, int destPos, int destLen) throws IOException {
+ if (dest == null) {
+ throw new NullPointerException();
Review Comment:
Done.
> Optimize shell -text command I/O with multi-byte read.
> ------------------------------------------------------
>
> Key: HADOOP-19389
> URL: https://issues.apache.org/jira/browse/HADOOP-19389
> Project: Hadoop Common
> Issue Type: Improvement
> Components: command, fs, fs/azure, fs/gcs, fs/s3
> Affects Versions: 3.4.1
> Reporter: Chris Nauroth
> Assignee: Chris Nauroth
> Priority: Minor
> Labels: pull-request-available
>
> {{hadoop fs -text}} reads Avro files and sequence files by internally
> wrapping the stream in
> [{{AvroFileInputStream}}|https://github.com/apache/hadoop/blob/rel/release-3.4.1/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/shell/Display.java#L270]
> or
> [{{TextRecordInputStream}}|https://github.com/apache/hadoop/blob/rel/release-3.4.1/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/shell/Display.java#L217].
> These classes implement the required single-byte
> [{{read()}}|https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/io/InputStream.html#read()],
> but not the optional multi-byte buffered [{{read(byte[], int,
> int)}}|https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/io/InputStream.html#read(byte%5B%5D,int,int)].
> The default implementation in the JDK is a [loop over single-byte
> read|https://github.com/openjdk/jdk11u-dev/blob/a47c72fad455bfdf9053cb8e94c99e73965ab50d/src/java.base/share/classes/java/io/InputStream.java#L280],
> which causes sub-optimal I/O and method call overhead. We can optimize this
> by overriding the multi-byte read method.
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