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https://issues.apache.org/jira/browse/FLINK-1980?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14534019#comment-14534019
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ASF GitHub Bot commented on FLINK-1980:
---------------------------------------
Github user rmetzger commented on a diff in the pull request:
https://github.com/apache/flink/pull/658#discussion_r29920838
--- Diff:
flink-core/src/main/java/org/apache/flink/api/common/io/InputStreamFSInputWrapper.java
---
@@ -0,0 +1,60 @@
+package org.apache.flink.api.common.io;
+
+import org.apache.flink.core.fs.FSDataInputStream;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * This class wraps an {@link java.io.InputStream} and exposes it as
{@link org.apache.flink.core.fs.FSDataInputStream}.
+ * <br>
+ * <i>NB: {@link #seek(long)} and {@link #getPos()} are currently not
supported.</i>
+ */
+public class InputStreamFSInputWrapper extends FSDataInputStream {
+
+ private final InputStream inStream;
+
+ private long pos = 0;
+
+ public InputStreamFSInputWrapper(InputStream inStream) {
+ this.inStream = inStream;
+ }
+
+ @Override
+ public void seek(long desired) throws IOException {
+ if (desired < this.pos) {
+ throw new IllegalArgumentException("Wrapped InputStream:
cannot search backwards.");
+ } else if (desired == pos) {
+ return;
+ }
+
+ this.inStream.skip(desired - pos);
+ this.pos = desired;
+ }
+
+ @Override
+ public long getPos() throws IOException {
+ return this.pos;
+ }
+
+ @Override
+ public int read() throws IOException {
+ int read = inStream.read();
+ if (read != -1) {
+ this.pos++;
+ }
+ return read;
+ }
+
+ @Override
+ public int read(byte[] b, int off, int len) throws IOException {
+ int numReadBytes = inStream.read(b, off, len);
--- End diff --
This method will return `-1` when the stream is over. Will this corrupt the
`pos` ? (Above, you're checking if `read != -1` ?)
> Allowing users to decorate input streams
> ----------------------------------------
>
> Key: FLINK-1980
> URL: https://issues.apache.org/jira/browse/FLINK-1980
> Project: Flink
> Issue Type: New Feature
> Components: Core
> Reporter: Sebastian Kruse
> Assignee: Sebastian Kruse
> Priority: Minor
>
> Users may have to do unforeseeable operations on file input streams before
> they can be used by the actual input format logic, e.g., exotic compression
> formats or preambles such as byte order marks. Therefore, it would be useful
> to provide the user with a hook to decorate input streams in order to handle
> such issues.
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