refactoring SeaweedInputStream

other/java/client/src/main/java/seaweedfs/client/SeaweedInputStream.java

@@ -1,28 +1,22 @@
-package seaweed.hdfs;
+package seaweedfs.client;
 
 // based on org.apache.hadoop.fs.azurebfs.services.AbfsInputStream
 
-import org.apache.hadoop.fs.ByteBufferReadable;
-import org.apache.hadoop.fs.FSExceptionMessages;
-import org.apache.hadoop.fs.FSInputStream;
-import org.apache.hadoop.fs.FileSystem.Statistics;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import seaweedfs.client.FilerGrpcClient;
-import seaweedfs.client.FilerProto;
-import seaweedfs.client.SeaweedRead;
 
 import java.io.EOFException;
 import java.io.IOException;
+import java.io.InputStream;
 import java.nio.ByteBuffer;
 import java.util.List;
 
-public class SeaweedInputStream extends FSInputStream implements ByteBufferReadable {
+public class SeaweedInputStream extends InputStream {
 
     private static final Logger LOG = LoggerFactory.getLogger(SeaweedInputStream.class);
+    private static final IOException EXCEPTION_STREAM_IS_CLOSED = new IOException("Stream is closed!");
 
     private final FilerGrpcClient filerGrpcClient;
-    private final Statistics statistics;
     private final String path;
     private final FilerProto.Entry entry;
     private final List<SeaweedRead.VisibleInterval> visibleIntervalList;
@@ -34,11 +28,9 @@ public class SeaweedInputStream extends FSInputStream implements ByteBufferReada
 
     public SeaweedInputStream(
             final FilerGrpcClient filerGrpcClient,
-            final Statistics statistics,
             final String path,
             final FilerProto.Entry entry) throws IOException {
         this.filerGrpcClient = filerGrpcClient;
-        this.statistics = statistics;
         this.path = path;
         this.entry = entry;
         this.contentLength = SeaweedRead.fileSize(entry);
@@ -86,7 +78,6 @@ public class SeaweedInputStream extends FSInputStream implements ByteBufferReada
     }
 
     // implement ByteBufferReadable
-    @Override
     public synchronized int read(ByteBuffer buf) throws IOException {
 
         if (position < 0) {
@@ -111,45 +102,32 @@ public class SeaweedInputStream extends FSInputStream implements ByteBufferReada
 
         if (bytesRead > 0) {
             this.position += bytesRead;
-            if (statistics != null) {
-                statistics.incrementBytesRead(bytesRead);
-            }
         }
 
         return (int) bytesRead;
     }
 
-    /**
-     * Seek to given position in stream.
-     *
-     * @param n position to seek to
-     * @throws IOException  if there is an error
-     * @throws EOFException if attempting to seek past end of file
-     */
-    @Override
     public synchronized void seek(long n) throws IOException {
         if (closed) {
-            throw new IOException(FSExceptionMessages.STREAM_IS_CLOSED);
+            throw EXCEPTION_STREAM_IS_CLOSED;
         }
         if (n < 0) {
-            throw new EOFException(FSExceptionMessages.NEGATIVE_SEEK);
+            throw new EOFException("Cannot seek to a negative offset");
         }
         if (n > contentLength) {
-            throw new EOFException(FSExceptionMessages.CANNOT_SEEK_PAST_EOF);
+            throw new EOFException("Attempted to seek or read past the end of the file");
         }
-
         this.position = n;
-
     }
 
     @Override
     public synchronized long skip(long n) throws IOException {
         if (closed) {
-            throw new IOException(FSExceptionMessages.STREAM_IS_CLOSED);
+            throw EXCEPTION_STREAM_IS_CLOSED;
         }
         if (this.position == contentLength) {
             if (n > 0) {
-                throw new EOFException(FSExceptionMessages.CANNOT_SEEK_PAST_EOF);
+                throw new EOFException("Attempted to seek or read past the end of the file");
             }
         }
         long newPos = this.position + n;
@@ -177,10 +155,9 @@ public class SeaweedInputStream extends FSInputStream implements ByteBufferReada
     @Override
     public synchronized int available() throws IOException {
         if (closed) {
-            throw new IOException(
+            throw EXCEPTION_STREAM_IS_CLOSED;
-                    FSExceptionMessages.STREAM_IS_CLOSED);
         }
-        final long remaining = this.contentLength - this.getPos();
+        final long remaining = this.contentLength - this.position;
         return remaining <= Integer.MAX_VALUE
                 ? (int) remaining : Integer.MAX_VALUE;
     }
@@ -195,65 +172,21 @@ public class SeaweedInputStream extends FSInputStream implements ByteBufferReada
      */
     public long length() throws IOException {
         if (closed) {
-            throw new IOException(FSExceptionMessages.STREAM_IS_CLOSED);
+            throw EXCEPTION_STREAM_IS_CLOSED;
         }
         return contentLength;
     }
 
-    /**
-     * Return the current offset from the start of the file
-     *
-     * @throws IOException throws {@link IOException} if there is an error
-     */
-    @Override
     public synchronized long getPos() throws IOException {
         if (closed) {
-            throw new IOException(FSExceptionMessages.STREAM_IS_CLOSED);
+            throw EXCEPTION_STREAM_IS_CLOSED;
         }
         return position;
     }
 
-    /**
-     * Seeks a different copy of the data.  Returns true if
-     * found a new source, false otherwise.
-     *
-     * @throws IOException throws {@link IOException} if there is an error
-     */
-    @Override
-    public boolean seekToNewSource(long l) throws IOException {
-        return false;
-    }
-
     @Override
     public synchronized void close() throws IOException {
         closed = true;
     }
 
-    /**
-     * Not supported by this stream. Throws {@link UnsupportedOperationException}
-     *
-     * @param readlimit ignored
-     */
-    @Override
-    public synchronized void mark(int readlimit) {
-        throw new UnsupportedOperationException("mark()/reset() not supported on this stream");
-    }
-
-    /**
-     * Not supported by this stream. Throws {@link UnsupportedOperationException}
-     */
-    @Override
-    public synchronized void reset() throws IOException {
-        throw new UnsupportedOperationException("mark()/reset() not supported on this stream");
-    }
-
-    /**
-     * gets whether mark and reset are supported by {@code ADLFileInputStream}. Always returns false.
-     *
-     * @return always {@code false}
-     */
-    @Override
-    public boolean markSupported() {
-        return false;
-    }
 }

other/java/examples/src/main/java/com/seaweedfs/examples/UnzipFile.java

@@ -1,6 +1,6 @@
 package com.seaweedfs.examples;
 
-import seaweed.hdfs.SeaweedInputStream;
+import seaweed.hdfs.SeaweedHadoopInputStream;
 import seaweedfs.client.FilerClient;
 import seaweedfs.client.FilerGrpcClient;
 
@@ -24,7 +24,7 @@ public class UnzipFile {
 
         long localProcessTime = startTime2 - startTime;
 
-        SeaweedInputStream seaweedInputStream = new SeaweedInputStream(
+        SeaweedHadoopInputStream seaweedInputStream = new SeaweedHadoopInputStream(
                 filerGrpcClient,
                 new org.apache.hadoop.fs.FileSystem.Statistics(""),
                 "/",

other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedFileSystemStore.java

@@ -230,7 +230,7 @@ public class SeaweedFileSystemStore {
             throw new FileNotFoundException("read non-exist file " + path);
         }
 
-        return new SeaweedInputStream(filerGrpcClient,
+        return new SeaweedHadoopInputStream(filerGrpcClient,
             statistics,
             path.toUri().getPath(),
             entry);

other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedHadoopInputStream.java

@@ -0,0 +1,150 @@
+package seaweed.hdfs;
+
+// based on org.apache.hadoop.fs.azurebfs.services.AbfsInputStream
+
+import org.apache.hadoop.fs.ByteBufferReadable;
+import org.apache.hadoop.fs.FSInputStream;
+import org.apache.hadoop.fs.FileSystem.Statistics;
+import seaweedfs.client.FilerGrpcClient;
+import seaweedfs.client.FilerProto;
+import seaweedfs.client.SeaweedInputStream;
+
+import java.io.EOFException;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+public class SeaweedHadoopInputStream extends FSInputStream implements ByteBufferReadable {
+
+    private final SeaweedInputStream seaweedInputStream;
+    private final Statistics statistics;
+
+    public SeaweedHadoopInputStream(
+            final FilerGrpcClient filerGrpcClient,
+            final Statistics statistics,
+            final String path,
+            final FilerProto.Entry entry) throws IOException {
+        this.seaweedInputStream = new SeaweedInputStream(filerGrpcClient, path, entry);
+        this.statistics = statistics;
+    }
+
+    @Override
+    public int read() throws IOException {
+        return seaweedInputStream.read();
+    }
+
+    @Override
+    public int read(final byte[] b, final int off, final int len) throws IOException {
+        return seaweedInputStream.read(b, off, len);
+    }
+
+    // implement ByteBufferReadable
+    @Override
+    public synchronized int read(ByteBuffer buf) throws IOException {
+        int bytesRead = seaweedInputStream.read(buf);
+
+        if (bytesRead > 0) {
+            if (statistics != null) {
+                statistics.incrementBytesRead(bytesRead);
+            }
+        }
+
+        return bytesRead;
+    }
+
+    /**
+     * Seek to given position in stream.
+     *
+     * @param n position to seek to
+     * @throws IOException  if there is an error
+     * @throws EOFException if attempting to seek past end of file
+     */
+    @Override
+    public synchronized void seek(long n) throws IOException {
+        seaweedInputStream.seek(n);
+    }
+
+    @Override
+    public synchronized long skip(long n) throws IOException {
+        return seaweedInputStream.skip(n);
+    }
+
+    /**
+     * Return the size of the remaining available bytes
+     * if the size is less than or equal to {@link Integer#MAX_VALUE},
+     * otherwise, return {@link Integer#MAX_VALUE}.
+     * <p>
+     * This is to match the behavior of DFSInputStream.available(),
+     * which some clients may rely on (HBase write-ahead log reading in
+     * particular).
+     */
+    @Override
+    public synchronized int available() throws IOException {
+        return seaweedInputStream.available();
+    }
+
+    /**
+     * Returns the length of the file that this stream refers to. Note that the length returned is the length
+     * as of the time the Stream was opened. Specifically, if there have been subsequent appends to the file,
+     * they wont be reflected in the returned length.
+     *
+     * @return length of the file.
+     * @throws IOException if the stream is closed
+     */
+    public long length() throws IOException {
+        return seaweedInputStream.length();
+    }
+
+    /**
+     * Return the current offset from the start of the file
+     *
+     * @throws IOException throws {@link IOException} if there is an error
+     */
+    @Override
+    public synchronized long getPos() throws IOException {
+        return seaweedInputStream.getPos();
+    }
+
+    /**
+     * Seeks a different copy of the data.  Returns true if
+     * found a new source, false otherwise.
+     *
+     * @throws IOException throws {@link IOException} if there is an error
+     */
+    @Override
+    public boolean seekToNewSource(long l) throws IOException {
+        return false;
+    }
+
+    @Override
+    public synchronized void close() throws IOException {
+        seaweedInputStream.close();
+    }
+
+    /**
+     * Not supported by this stream. Throws {@link UnsupportedOperationException}
+     *
+     * @param readlimit ignored
+     */
+    @Override
+    public synchronized void mark(int readlimit) {
+        throw new UnsupportedOperationException("mark()/reset() not supported on this stream");
+    }
+
+    /**
+     * Not supported by this stream. Throws {@link UnsupportedOperationException}
+     */
+    @Override
+    public synchronized void reset() throws IOException {
+        throw new UnsupportedOperationException("mark()/reset() not supported on this stream");
+    }
+
+    /**
+     * gets whether mark and reset are supported by {@code ADLFileInputStream}. Always returns false.
+     *
+     * @return always {@code false}
+     */
+    @Override
+    public boolean markSupported() {
+        return false;
+    }
+}

other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedFileSystemStore.java

@@ -230,7 +230,7 @@ public class SeaweedFileSystemStore {
             throw new FileNotFoundException("read non-exist file " + path);
         }
 
-        return new SeaweedInputStream(filerGrpcClient,
+        return new SeaweedHadoopInputStream(filerGrpcClient,
             statistics,
             path.toUri().getPath(),
             entry);

other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedHadoopInputStream.java

@@ -0,0 +1,150 @@
+package seaweed.hdfs;
+
+// based on org.apache.hadoop.fs.azurebfs.services.AbfsInputStream
+
+import org.apache.hadoop.fs.ByteBufferReadable;
+import org.apache.hadoop.fs.FSInputStream;
+import org.apache.hadoop.fs.FileSystem.Statistics;
+import seaweedfs.client.FilerGrpcClient;
+import seaweedfs.client.FilerProto;
+import seaweedfs.client.SeaweedInputStream;
+
+import java.io.EOFException;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+public class SeaweedHadoopInputStream extends FSInputStream implements ByteBufferReadable {
+
+    private final SeaweedInputStream seaweedInputStream;
+    private final Statistics statistics;
+
+    public SeaweedHadoopInputStream(
+            final FilerGrpcClient filerGrpcClient,
+            final Statistics statistics,
+            final String path,
+            final FilerProto.Entry entry) throws IOException {
+        this.seaweedInputStream = new SeaweedInputStream(filerGrpcClient, path, entry);
+        this.statistics = statistics;
+    }
+
+    @Override
+    public int read() throws IOException {
+        return seaweedInputStream.read();
+    }
+
+    @Override
+    public int read(final byte[] b, final int off, final int len) throws IOException {
+        return seaweedInputStream.read(b, off, len);
+    }
+
+    // implement ByteBufferReadable
+    @Override
+    public synchronized int read(ByteBuffer buf) throws IOException {
+        int bytesRead = seaweedInputStream.read(buf);
+
+        if (bytesRead > 0) {
+            if (statistics != null) {
+                statistics.incrementBytesRead(bytesRead);
+            }
+        }
+
+        return bytesRead;
+    }
+
+    /**
+     * Seek to given position in stream.
+     *
+     * @param n position to seek to
+     * @throws IOException  if there is an error
+     * @throws EOFException if attempting to seek past end of file
+     */
+    @Override
+    public synchronized void seek(long n) throws IOException {
+        seaweedInputStream.seek(n);
+    }
+
+    @Override
+    public synchronized long skip(long n) throws IOException {
+        return seaweedInputStream.skip(n);
+    }
+
+    /**
+     * Return the size of the remaining available bytes
+     * if the size is less than or equal to {@link Integer#MAX_VALUE},
+     * otherwise, return {@link Integer#MAX_VALUE}.
+     * <p>
+     * This is to match the behavior of DFSInputStream.available(),
+     * which some clients may rely on (HBase write-ahead log reading in
+     * particular).
+     */
+    @Override
+    public synchronized int available() throws IOException {
+        return seaweedInputStream.available();
+    }
+
+    /**
+     * Returns the length of the file that this stream refers to. Note that the length returned is the length
+     * as of the time the Stream was opened. Specifically, if there have been subsequent appends to the file,
+     * they wont be reflected in the returned length.
+     *
+     * @return length of the file.
+     * @throws IOException if the stream is closed
+     */
+    public long length() throws IOException {
+        return seaweedInputStream.length();
+    }
+
+    /**
+     * Return the current offset from the start of the file
+     *
+     * @throws IOException throws {@link IOException} if there is an error
+     */
+    @Override
+    public synchronized long getPos() throws IOException {
+        return seaweedInputStream.getPos();
+    }
+
+    /**
+     * Seeks a different copy of the data.  Returns true if
+     * found a new source, false otherwise.
+     *
+     * @throws IOException throws {@link IOException} if there is an error
+     */
+    @Override
+    public boolean seekToNewSource(long l) throws IOException {
+        return false;
+    }
+
+    @Override
+    public synchronized void close() throws IOException {
+        seaweedInputStream.close();
+    }
+
+    /**
+     * Not supported by this stream. Throws {@link UnsupportedOperationException}
+     *
+     * @param readlimit ignored
+     */
+    @Override
+    public synchronized void mark(int readlimit) {
+        throw new UnsupportedOperationException("mark()/reset() not supported on this stream");
+    }
+
+    /**
+     * Not supported by this stream. Throws {@link UnsupportedOperationException}
+     */
+    @Override
+    public synchronized void reset() throws IOException {
+        throw new UnsupportedOperationException("mark()/reset() not supported on this stream");
+    }
+
+    /**
+     * gets whether mark and reset are supported by {@code ADLFileInputStream}. Always returns false.
+     *
+     * @return always {@code false}
+     */
+    @Override
+    public boolean markSupported() {
+        return false;
+    }
+}

other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedInputStream.java

@@ -1,259 +0,0 @@
-package seaweed.hdfs;
-
-// based on org.apache.hadoop.fs.azurebfs.services.AbfsInputStream
-
-import org.apache.hadoop.fs.ByteBufferReadable;
-import org.apache.hadoop.fs.FSExceptionMessages;
-import org.apache.hadoop.fs.FSInputStream;
-import org.apache.hadoop.fs.FileSystem.Statistics;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-import seaweedfs.client.FilerGrpcClient;
-import seaweedfs.client.FilerProto;
-import seaweedfs.client.SeaweedRead;
-
-import java.io.EOFException;
-import java.io.IOException;
-import java.nio.ByteBuffer;
-import java.util.List;
-
-public class SeaweedInputStream extends FSInputStream implements ByteBufferReadable {
-
-    private static final Logger LOG = LoggerFactory.getLogger(SeaweedInputStream.class);
-
-    private final FilerGrpcClient filerGrpcClient;
-    private final Statistics statistics;
-    private final String path;
-    private final FilerProto.Entry entry;
-    private final List<SeaweedRead.VisibleInterval> visibleIntervalList;
-    private final long contentLength;
-
-    private long position = 0;  // cursor of the file
-
-    private boolean closed = false;
-
-    public SeaweedInputStream(
-            final FilerGrpcClient filerGrpcClient,
-            final Statistics statistics,
-            final String path,
-            final FilerProto.Entry entry) throws IOException {
-        this.filerGrpcClient = filerGrpcClient;
-        this.statistics = statistics;
-        this.path = path;
-        this.entry = entry;
-        this.contentLength = SeaweedRead.fileSize(entry);
-
-        this.visibleIntervalList = SeaweedRead.nonOverlappingVisibleIntervals(filerGrpcClient, entry.getChunksList());
-
-        LOG.debug("new path:{} entry:{} visibleIntervalList:{}", path, entry, visibleIntervalList);
-
-    }
-
-    public String getPath() {
-        return path;
-    }
-
-    @Override
-    public int read() throws IOException {
-        byte[] b = new byte[1];
-        int numberOfBytesRead = read(b, 0, 1);
-        if (numberOfBytesRead < 0) {
-            return -1;
-        } else {
-            return (b[0] & 0xFF);
-        }
-    }
-
-    @Override
-    public int read(final byte[] b, final int off, final int len) throws IOException {
-
-        if (b == null) {
-            throw new IllegalArgumentException("null byte array passed in to read() method");
-        }
-        if (off >= b.length) {
-            throw new IllegalArgumentException("offset greater than length of array");
-        }
-        if (len < 0) {
-            throw new IllegalArgumentException("requested read length is less than zero");
-        }
-        if (len > (b.length - off)) {
-            throw new IllegalArgumentException("requested read length is more than will fit after requested offset in buffer");
-        }
-
-        ByteBuffer buf = ByteBuffer.wrap(b, off, len);
-        return read(buf);
-
-    }
-
-    // implement ByteBufferReadable
-    @Override
-    public synchronized int read(ByteBuffer buf) throws IOException {
-
-        if (position < 0) {
-            throw new IllegalArgumentException("attempting to read from negative offset");
-        }
-        if (position >= contentLength) {
-            return -1;  // Hadoop prefers -1 to EOFException
-        }
-
-        long bytesRead = 0;
-        int len = buf.remaining();
-        int start = (int) this.position;
-        if (start+len <= entry.getContent().size()) {
-            entry.getContent().substring(start, start+len).copyTo(buf);
-        } else {
-            bytesRead = SeaweedRead.read(this.filerGrpcClient, this.visibleIntervalList, this.position, buf, SeaweedRead.fileSize(entry));
-        }
-
-        if (bytesRead > Integer.MAX_VALUE) {
-            throw new IOException("Unexpected Content-Length");
-        }
-
-        if (bytesRead > 0) {
-            this.position += bytesRead;
-            if (statistics != null) {
-                statistics.incrementBytesRead(bytesRead);
-            }
-        }
-
-        return (int) bytesRead;
-    }
-
-    /**
-     * Seek to given position in stream.
-     *
-     * @param n position to seek to
-     * @throws IOException  if there is an error
-     * @throws EOFException if attempting to seek past end of file
-     */
-    @Override
-    public synchronized void seek(long n) throws IOException {
-        if (closed) {
-            throw new IOException(FSExceptionMessages.STREAM_IS_CLOSED);
-        }
-        if (n < 0) {
-            throw new EOFException(FSExceptionMessages.NEGATIVE_SEEK);
-        }
-        if (n > contentLength) {
-            throw new EOFException(FSExceptionMessages.CANNOT_SEEK_PAST_EOF);
-        }
-
-        this.position = n;
-
-    }
-
-    @Override
-    public synchronized long skip(long n) throws IOException {
-        if (closed) {
-            throw new IOException(FSExceptionMessages.STREAM_IS_CLOSED);
-        }
-        if (this.position == contentLength) {
-            if (n > 0) {
-                throw new EOFException(FSExceptionMessages.CANNOT_SEEK_PAST_EOF);
-            }
-        }
-        long newPos = this.position + n;
-        if (newPos < 0) {
-            newPos = 0;
-            n = newPos - this.position;
-        }
-        if (newPos > contentLength) {
-            newPos = contentLength;
-            n = newPos - this.position;
-        }
-        seek(newPos);
-        return n;
-    }
-
-    /**
-     * Return the size of the remaining available bytes
-     * if the size is less than or equal to {@link Integer#MAX_VALUE},
-     * otherwise, return {@link Integer#MAX_VALUE}.
-     * <p>
-     * This is to match the behavior of DFSInputStream.available(),
-     * which some clients may rely on (HBase write-ahead log reading in
-     * particular).
-     */
-    @Override
-    public synchronized int available() throws IOException {
-        if (closed) {
-            throw new IOException(
-                    FSExceptionMessages.STREAM_IS_CLOSED);
-        }
-        final long remaining = this.contentLength - this.getPos();
-        return remaining <= Integer.MAX_VALUE
-                ? (int) remaining : Integer.MAX_VALUE;
-    }
-
-    /**
-     * Returns the length of the file that this stream refers to. Note that the length returned is the length
-     * as of the time the Stream was opened. Specifically, if there have been subsequent appends to the file,
-     * they wont be reflected in the returned length.
-     *
-     * @return length of the file.
-     * @throws IOException if the stream is closed
-     */
-    public long length() throws IOException {
-        if (closed) {
-            throw new IOException(FSExceptionMessages.STREAM_IS_CLOSED);
-        }
-        return contentLength;
-    }
-
-    /**
-     * Return the current offset from the start of the file
-     *
-     * @throws IOException throws {@link IOException} if there is an error
-     */
-    @Override
-    public synchronized long getPos() throws IOException {
-        if (closed) {
-            throw new IOException(FSExceptionMessages.STREAM_IS_CLOSED);
-        }
-        return position;
-    }
-
-    /**
-     * Seeks a different copy of the data.  Returns true if
-     * found a new source, false otherwise.
-     *
-     * @throws IOException throws {@link IOException} if there is an error
-     */
-    @Override
-    public boolean seekToNewSource(long l) throws IOException {
-        return false;
-    }
-
-    @Override
-    public synchronized void close() throws IOException {
-        closed = true;
-    }
-
-    /**
-     * Not supported by this stream. Throws {@link UnsupportedOperationException}
-     *
-     * @param readlimit ignored
-     */
-    @Override
-    public synchronized void mark(int readlimit) {
-        throw new UnsupportedOperationException("mark()/reset() not supported on this stream");
-    }
-
-    /**
-     * Not supported by this stream. Throws {@link UnsupportedOperationException}
-     */
-    @Override
-    public synchronized void reset() throws IOException {
-        throw new UnsupportedOperationException("mark()/reset() not supported on this stream");
-    }
-
-    /**
-     * gets whether mark and reset are supported by {@code ADLFileInputStream}. Always returns false.
-     *
-     * @return always {@code false}
-     */
-    @Override
-    public boolean markSupported() {
-        return false;
-    }
-}