com.signalfx.shaded.apache.commons.io.input.UnsynchronizedFilterInputStream 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 com.signalfx.shaded.apache.commons.io.input;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import com.signalfx.shaded.apache.commons.io.build.AbstractStreamBuilder;
/**
* An unsynchronized version of {@link FilterInputStream}, not thread-safe.
*
* Wraps an existing {@link InputStream} and performs some transformation on the input data while it is being read. Transformations can be anything from a
* simple byte-wise filtering input data to an on-the-fly compression or decompression of the underlying stream. Input streams that wrap another input stream
* and provide some additional functionality on top of it usually inherit from this class.
*
*
* To build an instance, see {@link Builder}.
*
*
* Provenance: Apache Harmony and modified.
*
*
* @see FilterInputStream
* @since 2.12.0
*/
//@NotThreadSafe
public class UnsynchronizedFilterInputStream extends InputStream {
/**
* Builds a new {@link UnsynchronizedFilterInputStream} instance.
*
* Using File IO:
*
* {@code
* UnsynchronizedFilterInputStream s = UnsynchronizedFilterInputStream.builder()
* .setFile(file)
* .get();}
*
*
* Using NIO Path:
*
* {@code
* UnsynchronizedFilterInputStream s = UnsynchronizedFilterInputStream.builder()
* .setPath(path)
* .get();}
*
*/
public static class Builder extends AbstractStreamBuilder {
/**
* Constructs a new instance.
*
* This builder use the aspect InputStream and OpenOption[].
*
*
* You must provide an origin that can be converted to an InputStream by this builder, otherwise, this call will throw an
* {@link UnsupportedOperationException}.
*
*
* @return a new instance.
* @throws UnsupportedOperationException if the origin cannot provide an InputStream.
* @see #getInputStream()
*/
@SuppressWarnings("resource") // Caller closes.
@Override
public UnsynchronizedFilterInputStream get() throws IOException {
return new UnsynchronizedFilterInputStream(getInputStream());
}
}
/**
* Constructs a new {@link Builder}.
*
* @return a new {@link Builder}.
*/
public static Builder builder() {
return new Builder();
}
/**
* The source input stream that is filtered.
*/
protected volatile InputStream inputStream;
/**
* Constructs a new {@code FilterInputStream} with the specified input stream as source.
*
* @param inputStream the non-null InputStream to filter reads on.
*/
UnsynchronizedFilterInputStream(final InputStream inputStream) {
this.inputStream = inputStream;
}
/**
* Returns the number of bytes that are available before this stream will block.
*
* @return the number of bytes available before blocking.
* @throws IOException if an error occurs in this stream.
*/
@Override
public int available() throws IOException {
return inputStream.available();
}
/**
* Closes this stream. This implementation closes the filtered stream.
*
* @throws IOException if an error occurs while closing this stream.
*/
@Override
public void close() throws IOException {
inputStream.close();
}
/**
* Sets a mark position in this stream. The parameter {@code readlimit} indicates how many bytes can be read before the mark is invalidated. Sending
* {@code reset()} will reposition this stream back to the marked position, provided that {@code readlimit} has not been surpassed.
*
* This implementation sets a mark in the filtered stream.
*
* @param readlimit the number of bytes that can be read from this stream before the mark is invalidated.
* @see #markSupported()
* @see #reset()
*/
@SuppressWarnings("sync-override") // by design.
@Override
public void mark(final int readlimit) {
inputStream.mark(readlimit);
}
/**
* Indicates whether this stream supports {@code mark()} and {@code reset()}. This implementation returns whether or not the filtered stream supports
* marking.
*
* @return {@code true} if {@code mark()} and {@code reset()} are supported, {@code false} otherwise.
* @see #mark(int)
* @see #reset()
* @see #skip(long)
*/
@Override
public boolean markSupported() {
return inputStream.markSupported();
}
/**
* Reads a single byte from the filtered stream and returns it as an integer in the range from 0 to 255. Returns -1 if the end of this stream has been
* reached.
*
* @return the byte read or -1 if the end of the filtered stream has been reached.
* @throws IOException if the stream is closed or another IOException occurs.
*/
@Override
public int read() throws IOException {
return inputStream.read();
}
/**
* Reads bytes from this stream and stores them in the byte array {@code buffer}. Returns the number of bytes actually read or -1 if no bytes were read and
* the end of this stream was encountered. This implementation reads bytes from the filtered stream.
*
* @param buffer the byte array in which to store the read bytes.
* @return the number of bytes actually read or -1 if the end of the filtered stream has been reached while reading.
* @throws IOException if this stream is closed or another IOException occurs.
*/
@Override
public int read(final byte[] buffer) throws IOException {
return read(buffer, 0, buffer.length);
}
/**
* Reads at most {@code count} bytes from this stream and stores them in the byte array {@code buffer} starting at {@code offset}. Returns the number of
* bytes actually read or -1 if no bytes have been read and the end of this stream has been reached. This implementation reads bytes from the filtered
* stream.
*
* @param buffer the byte array in which to store the bytes read.
* @param offset the initial position in {@code buffer} to store the bytes read from this stream.
* @param count the maximum number of bytes to store in {@code buffer}.
* @return the number of bytes actually read or -1 if the end of the filtered stream has been reached while reading.
* @throws IOException if this stream is closed or another I/O error occurs.
*/
@Override
public int read(final byte[] buffer, final int offset, final int count) throws IOException {
return inputStream.read(buffer, offset, count);
}
/**
* Resets this stream to the last marked location. This implementation resets the target stream.
*
* @throws IOException if this stream is already closed, no mark has been set or the mark is no longer valid because more than {@code readlimit} bytes have
* been read since setting the mark.
* @see #mark(int)
* @see #markSupported()
*/
@SuppressWarnings("sync-override") // by design.
@Override
public void reset() throws IOException {
inputStream.reset();
}
/**
* Skips {@code count} number of bytes in this stream. Subsequent {@code read()}'s will not return these bytes unless {@code reset()} is used. This
* implementation skips {@code count} number of bytes in the filtered stream.
*
* @param count the number of bytes to skip.
* @return the number of bytes actually skipped.
* @throws IOException if this stream is closed or another IOException occurs.
* @see #mark(int)
* @see #reset()
*/
@Override
public long skip(final long count) throws IOException {
return inputStream.skip(count);
}
}