54 lines
2.1 KiB
Java
54 lines
2.1 KiB
Java
package org.warp.commonutils.stream;
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/*
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* Copyright (C) 2005-2020 Sebastiano Vigna
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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import it.unimi.dsi.fastutil.io.FastBufferedInputStream;
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import it.unimi.dsi.fastutil.io.FastBufferedOutputStream;
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import it.unimi.dsi.fastutil.io.MeasurableInputStream;
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/** An stream that provides eager access to its length,
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* and keeps track of the current position (e.g., the number of bytes read so far, or the current
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* position of the file pointer).
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*
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* <p>This class has two methods, both specified as optional. This apparently bizarre
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* behaviour is necessary because of wrapper classes which use reflection
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* to support those methods (see, e.g., {@link MeasurableInputStream}, {@link FastBufferedInputStream} and {@link FastBufferedOutputStream}).
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*
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* @since 6.0.0
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*/
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public interface SafeMeasurableStream {
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/** Returns the overall length of this stream (optional operation). In most cases, this will require the
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* stream to perform some extra action, possibly changing the state of the input stream itself (typically, reading
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* all the bytes up to the end, or flushing on output stream).
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* Implementing classes should always document what state will the input stream be in
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* after calling this method, and which kind of exception could be thrown.
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*/
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long length();
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/** Returns the current position in this stream (optional operation).
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*
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* <p>Usually, the position is just the number of bytes read or written
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* since the stream was opened, but in the case of a
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* {@link it.unimi.dsi.fastutil.io.RepositionableStream} it
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* represent the current position.
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*/
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long position();
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}
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