org.apache.commons.io.output.ChunkedWriter 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.commons.io.output;
import java.io.FilterWriter;
import java.io.IOException;
import java.io.Writer;
/**
* Writer which breaks larger output blocks into chunks.
* Native code may need to copy the input array; if the write buffer
* is very large this can cause OOME.
*
* @since 2.5
*/
public class ChunkedWriter extends FilterWriter {
/**
* The default chunk size to use, i.e. {@value} bytes.
*/
private static final int DEFAULT_CHUNK_SIZE = 1024 * 4;
/**
* The maximum chunk size to us when writing data arrays
*/
private final int chunkSize;
/**
* Creates a new writer that uses the specified chunk size.
*
* @param writer the writer to wrap
* @param chunkSize the chunk size to use; must be a positive number.
* @throws IllegalArgumentException if the chunk size is <= 0
*/
public ChunkedWriter(final Writer writer, final int chunkSize) {
super(writer);
if (chunkSize <= 0) {
throw new IllegalArgumentException();
}
this.chunkSize = chunkSize;
}
/**
* Creates a new writer that uses a chunk size of {@link #DEFAULT_CHUNK_SIZE}
* @param writer the writer to wrap
*/
public ChunkedWriter(final Writer writer) {
this(writer, DEFAULT_CHUNK_SIZE);
}
/**
* writes the data buffer in chunks to the underlying writer
* @param data The data
* @param srcOffset the offset
* @param length the number of bytes to write
*
* @throws IOException upon error
*/
@Override
public void write(final char[] data, final int srcOffset, final int length) throws IOException {
int bytes = length;
int dstOffset = srcOffset;
while(bytes > 0) {
final int chunk = Math.min(bytes, chunkSize);
out.write(data, dstOffset, chunk);
bytes -= chunk;
dstOffset += chunk;
}
}
}