From 6f4aab51f9d7e8d9721c3c4fd7b57da7ab8b6d8e Mon Sep 17 00:00:00 2001 From: Chris Lu Date: Sat, 30 Jan 2021 06:16:02 -0800 Subject: [PATCH] refactoring SeaweedInputStream --- .../seaweedfs/client}/SeaweedInputStream.java | 93 +------ .../com/seaweedfs/examples/UnzipFile.java | 4 +- .../seaweed/hdfs/SeaweedFileSystemStore.java | 2 +- .../hdfs/SeaweedHadoopInputStream.java | 150 ++++++++++ .../seaweed/hdfs/SeaweedFileSystemStore.java | 2 +- .../hdfs/SeaweedHadoopInputStream.java | 150 ++++++++++ .../java/seaweed/hdfs/SeaweedInputStream.java | 259 ------------------ 7 files changed, 317 insertions(+), 343 deletions(-) rename other/java/{hdfs2/src/main/java/seaweed/hdfs => client/src/main/java/seaweedfs/client}/SeaweedInputStream.java (64%) create mode 100644 other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedHadoopInputStream.java create mode 100644 other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedHadoopInputStream.java delete mode 100644 other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedInputStream.java diff --git a/other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedInputStream.java b/other/java/client/src/main/java/seaweedfs/client/SeaweedInputStream.java similarity index 64% rename from other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedInputStream.java rename to other/java/client/src/main/java/seaweedfs/client/SeaweedInputStream.java index 690366849..312e77aa2 100644 --- a/other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedInputStream.java +++ b/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 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( - FSExceptionMessages.STREAM_IS_CLOSED); + throw EXCEPTION_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; - } } diff --git a/other/java/examples/src/main/java/com/seaweedfs/examples/UnzipFile.java b/other/java/examples/src/main/java/com/seaweedfs/examples/UnzipFile.java index 0529a5c73..317327be4 100644 --- a/other/java/examples/src/main/java/com/seaweedfs/examples/UnzipFile.java +++ b/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(""), "/", diff --git a/other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedFileSystemStore.java b/other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedFileSystemStore.java index 719e52579..223036c13 100644 --- a/other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedFileSystemStore.java +++ b/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); diff --git a/other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedHadoopInputStream.java b/other/java/hdfs2/src/main/java/seaweed/hdfs/SeaweedHadoopInputStream.java new file mode 100644 index 000000000..dd9bf4032 --- /dev/null +++ b/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}. + *

+ * 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; + } +} diff --git a/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedFileSystemStore.java b/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedFileSystemStore.java index 719e52579..223036c13 100644 --- a/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedFileSystemStore.java +++ b/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); diff --git a/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedHadoopInputStream.java b/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedHadoopInputStream.java new file mode 100644 index 000000000..dd9bf4032 --- /dev/null +++ b/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}. + *

+ * 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; + } +} diff --git a/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedInputStream.java b/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedInputStream.java deleted file mode 100644 index 690366849..000000000 --- a/other/java/hdfs3/src/main/java/seaweed/hdfs/SeaweedInputStream.java +++ /dev/null @@ -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 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}. - *

- * 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; - } -}