org.apache.flume.serialization.ResettableInputStream Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.flume.serialization;
import org.apache.flume.annotations.InterfaceAudience;
import org.apache.flume.annotations.InterfaceStability;
import java.io.Closeable;
import java.io.IOException;
/**
* This abstract class defines an interface for which
* the stream may be marked and reset with no limit to
* the number of bytes which may have been read between the calls.
*
*
Any implementation of this interface guarantees that the mark position
* will not be invalidated by reading any number of bytes.
*
*
Warning: We reserve the right to add public methods to this class in
* the future. Third-party subclasses beware.
*/
@InterfaceAudience.Public
@InterfaceStability.Unstable
public abstract class ResettableInputStream implements Resettable, Seekable,
Closeable {
/**
* Read a single byte of data from the stream.
* @return the next byte of data, or {@code -1} if the end of the stream has
* been reached.
* @throws IOException
*/
public abstract int read() throws IOException;
/**
* Read multiple bytes of data from the stream.
* @param b the buffer into which the data is read.
* @param off Offset into the array {@code b} at which the data is written.
* @param len the maximum number of bytes to read.
* @return the total number of bytes read into the buffer, or {@code -1} if
* the end of the stream has been reached.
* @throws IOException
*/
public abstract int read(byte[] b, int off, int len) throws IOException;
/**
*
Read a single character.
*
*
Note that this may lead to returning only one character in a 2-char
* surrogate pair sequence. When this happens, the underlying implementation
* should never persist a mark between two chars of a two-char surrogate
* pair sequence.
*
* @return The character read, as an integer in the range 0 to 65535
* (0x00-0xffff), or -1 if the end of the stream has been reached
* @throws IOException
*/
public abstract int readChar() throws IOException;
/**
* Marks the current position in this input stream. A subsequent call to the
* reset method repositions this stream at the last marked
* position so that subsequent reads re-read the same bytes.
*
*
Marking a closed stream should not have any effect on the stream.
*
* @throws IOException If there is an error while setting the mark position.
*
* @see java.io.InputStream#mark(int)
* @see java.io.InputStream#reset()
*/
@Override
public abstract void mark() throws IOException;
/**
* Reset stream position to that set by {@link #mark()}
* @throws IOException
*/
@Override
public abstract void reset() throws IOException;
/**
* Seek to the specified byte position in the stream.
* @param position Absolute byte offset to seek to
*/
@Override
public abstract void seek(long position) throws IOException;
/**
* Tell the current byte position.
* @return the current absolute byte position in the stream
*/
@Override
public abstract long tell() throws IOException;
@Override
public abstract void close() throws IOException;
}