[
https://issues.apache.org/jira/browse/HADOOP-17347?focusedWorklogId=524815&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-524815
]
ASF GitHub Bot logged work on HADOOP-17347:
-------------------------------------------
Author: ASF GitHub Bot
Created on: 16/Dec/20 03:37
Start Date: 16/Dec/20 03:37
Worklog Time Spent: 10m
Work Description: snvijaya commented on a change in pull request #2464:
URL: https://github.com/apache/hadoop/pull/2464#discussion_r543887310
##########
File path:
hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/services/AbfsInputStream.java
##########
@@ -206,11 +231,127 @@ private int readOneBlock(final byte[] b, final int off,
final int len) throws IO
fCursor += bytesRead;
fCursorAfterLastRead = fCursor;
}
+ return copyToUserBuffer(b, off, len);
+ }
+ private int readFileCompletely(final byte[] b, final int off, final int len)
+ throws IOException {
+ if (len == 0) {
+ return 0;
+ }
+ if (!validate(b, off, len)) {
+ return -1;
+ }
+ savePointerState();
+
+ buffer = new byte[bufferSize];
+ // data need to be copied to user buffer from index bCursor, bCursor has
+ // to be the current fCusor
+ bCursor = (int) fCursor;
+ return optimisedRead(b, off, len, 0, contentLength);
+ }
+
+ private int readLastBlock(final byte[] b, final int off, final int len)
+ throws IOException {
+ if (len == 0) {
+ return 0;
+ }
+ if (!validate(b, off, len)) {
+ return -1;
+ }
+ savePointerState();
+
+ buffer = new byte[bufferSize];
+ // data need to be copied to user buffer from index bCursor,
+ // AbfsInutStream buffer is going p contain dta from footer start. In
+ // that case bCursor will be set to footerStart - fCursor
+ long lastBlockStart = max(0, contentLength - bufferSize);
+ bCursor = (int) (fCursor - lastBlockStart);
+ // read API call is considered 1 single operation in reality server could
+ // return partial data and client has to retry untill the last full block
+ // is read. So setting the fCursorAfterLastRead before the possible
+ // multiple server calls
+ fCursorAfterLastRead = fCursor;
+ // 0 if contentlength is < buffersize
+ long actualLenToRead = min(bufferSize, contentLength);
+ return optimisedRead(b, off, len, lastBlockStart, actualLenToRead);
+ }
+
+ private int optimisedRead(final byte[] b, final int off, final int len,
+ final long readFrom, final long actualLen) throws IOException {
Review comment:
Rename actualLen to fileSize
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
[email protected]
Issue Time Tracking
-------------------
Worklog Id: (was: 524815)
Time Spent: 7.5h (was: 7h 20m)
> ABFS: Read optimizations
> ------------------------
>
> Key: HADOOP-17347
> URL: https://issues.apache.org/jira/browse/HADOOP-17347
> Project: Hadoop Common
> Issue Type: Sub-task
> Components: fs/azure
> Affects Versions: 3.4.0
> Reporter: Bilahari T H
> Assignee: Bilahari T H
> Priority: Major
> Labels: pull-request-available
> Time Spent: 7.5h
> Remaining Estimate: 0h
>
> Optimize read performance for the following scenarios
> # Read small files completely
> Files that are of size smaller than the read buffer size can be considered
> as small files. In case of such files it would be better to read the full
> file into the AbfsInputStream buffer.
> # Read last block if the read is for footer
> If the read is for the last 8 bytes, read the full file.
> This will optimize reads for parquet files. [Parquet file
> format|https://www.ellicium.com/parquet-file-format-structure/]
> Both these optimizations will be present under configs as follows
> # fs.azure.read.smallfilescompletely
> # fs.azure.read.optimizefooterread
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
