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https://issues.apache.org/jira/browse/HADOOP-19303?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17929944#comment-17929944
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ASF GitHub Bot commented on HADOOP-19303:
-----------------------------------------
cnauroth commented on code in PR #7418:
URL: https://github.com/apache/hadoop/pull/7418#discussion_r1968617441
##########
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/PositionedReadable.java:
##########
@@ -136,4 +137,30 @@ default void readVectored(List<? extends FileRange> ranges,
IntFunction<ByteBuffer> allocate) throws
IOException {
VectoredReadUtils.readVectored(this, ranges, allocate);
}
+
+ /**
+ * Variant of {@link #readVectored(List, IntFunction)} where a release()
function
+ * may be invoked if problems surface during reads -this method is called to
+ * try to return any allocated buffer which has not been read yet.
+ * Buffers which have successfully been read and returned to the caller do
not
+ * get released: this is for failures only.
+ * <p>
+ * The default implementation calls readVectored/2 so as to ensure that
+ * if an existing stream implementation does not implement this method
+ * all is good.
+ * <p>
+ * Implementations SHOULD override this method if they can release buffers as
+ * part of their error handling.
+ * @param ranges the byte ranges to read
+ * @param allocate the function to allocate ByteBuffer
+ * @param release the function to release a ByteBuffer.
+ * @throws IOException any IOE.
+ * @throws IllegalArgumentException if the any of ranges are invalid, or
they overlap.
Review Comment:
nit: seems like some words are out of order. Maybe "if any of the ranges..."?
##########
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/RawLocalFileSystem.java:
##########
@@ -319,74 +321,125 @@ AsynchronousFileChannel getAsyncChannel() throws
IOException {
@Override
public void readVectored(List<? extends FileRange> ranges,
IntFunction<ByteBuffer> allocate) throws
IOException {
+ readVectored(ranges, allocate, LOG_BYTE_BUFFER_RELEASED);
+ }
+
+ @Override
+ public void readVectored(final List<? extends FileRange> ranges,
+ final IntFunction<ByteBuffer> allocate,
+ final Consumer<ByteBuffer> release) throws IOException {
// Validate, but do not pass in a file length as it may change.
List<? extends FileRange> sortedRanges = sortRangeList(ranges);
- // Set up all of the futures, so that we can use them if things fail
- for(FileRange range: sortedRanges) {
+ // Set up all of the futures, so that the caller can await on
+ // their competion.
Review Comment:
nit: "completion"
##########
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FSDataInputStream.java:
##########
@@ -306,4 +307,11 @@ public void readVectored(List<? extends FileRange> ranges,
IntFunction<ByteBuffer> allocate) throws
IOException {
((PositionedReadable) in).readVectored(ranges, allocate);
}
+
+ @Override
+ public void readVectored(final List<? extends FileRange> ranges,
Review Comment:
Do we need coverage of this in the spec?
https://hadoop.apache.org/docs/current/hadoop-project-dist/hadoop-common/filesystem/fsdatainputstream.html#void_readVectored.28List.3C.3F_extends_FileRange.3E_ranges.2C_IntFunction.3CByteBuffer.3E_allocate.29
> VectorIO API to support releasing buffers on failure
> ----------------------------------------------------
>
> Key: HADOOP-19303
> URL: https://issues.apache.org/jira/browse/HADOOP-19303
> Project: Hadoop Common
> Issue Type: Sub-task
> Components: fs, fs/s3
> Affects Versions: 3.4.1
> Reporter: Steve Loughran
> Assignee: Steve Loughran
> Priority: Major
> Labels: pull-request-available
>
> extend for vector IO API with a method that takes a ByteBufferPool
> implementation rather than just an allocator. This allows for buffers to be
> returned to the pool when problems occur, before throwing an exception.
> The Parquet API is already designed for this
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