    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.io.output;
    018
    019import java.io.FilterOutputStream;
    020import java.io.IOException;
    021import java.io.OutputStream;
    022
    023import org.apache.commons.io.IOUtils;
    024import org.apache.commons.io.build.AbstractStreamBuilder;
    025
    026/**
    027 * OutputStream 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
    028 * OOME.
    029 * <p>
    030 * To build an instance, see {@link Builder}
    031 * </p>
    032 *
    033 * @see Builder
    034 * @since 2.5
    035 */
    036public class ChunkedOutputStream extends FilterOutputStream {
    037
    038    // @formatter:off
    039    /**
    040     * Builds a new {@link UnsynchronizedByteArrayOutputStream}.
    041     *
    042     * <p>
    043     * Using File IO:
    044     * </p>
    045     * <pre>{@code
    046     * UnsynchronizedByteArrayOutputStream s = UnsynchronizedByteArrayOutputStream.builder()
    047     *   .setBufferSize(8192)
    048     *   .get();
    049     * }
    050     * </pre>
    051     * <p>
    052     * Using NIO Path:
    053     * </p>
    054     * <pre>{@code
    055     * UnsynchronizedByteArrayOutputStream s = UnsynchronizedByteArrayOutputStream.builder()
    056     *   .setBufferSize(8192)
    057     *   .get();
    058     * }
    059     * </pre>
    060     *
    061     * @see #get()
    062     * @since 2.13.0
    063     */
    064    // @formatter:on
    065    public static class Builder extends AbstractStreamBuilder<ChunkedOutputStream, Builder> {
    066
    067        /**
    068         * Builds a new {@link UnsynchronizedByteArrayOutputStream}.
    069         * <p>
    070         * This builder use the following aspects:
    071         * </p>
    072         * <ul>
    073         * <li>{@link #getInputStream()}</li>
    074         * <li>{@link #getBufferSize()} (chunk size)</li>
    075         * </ul>
    076         *
    077         * @return a new instance.
    078         * @throws IllegalStateException         if the {@code origin} is {@code null}.
    079         * @throws UnsupportedOperationException if the origin cannot be converted to an {@link OutputStream}.
    080         * @throws IOException                   if an I/O error occurs.
    081         * @see #getOutputStream()
    082         * @see #getBufferSize()
    083         */
    084        @Override
    085        public ChunkedOutputStream get() throws IOException {
    086            return new ChunkedOutputStream(getOutputStream(), getBufferSize());
    087        }
    088
    089    }
    090
    091    /**
    092     * Constructs a new {@link Builder}.
    093     *
    094     * @return a new {@link Builder}.
    095     * @since 2.13.0
    096     */
    097    public static Builder builder() {
    098        return new Builder();
    099    }
    100
    101    /**
    102     * The maximum chunk size to us when writing data arrays
    103     */
    104    private final int chunkSize;
    105
    106    /**
    107     * Constructs a new stream that uses a chunk size of {@link IOUtils#DEFAULT_BUFFER_SIZE}.
    108     *
    109     * @param stream the stream to wrap
    110     * @deprecated Use {@link #builder()}, {@link Builder}, and {@link Builder#get()}
    111     */
    112    @Deprecated
    113    public ChunkedOutputStream(final OutputStream stream) {
    114        this(stream, IOUtils.DEFAULT_BUFFER_SIZE);
    115    }
    116
    117    /**
    118     * Constructs a new stream that uses the specified chunk size.
    119     *
    120     * @param stream    the stream to wrap
    121     * @param chunkSize the chunk size to use; must be a positive number.
    122     * @throws IllegalArgumentException if the chunk size is &lt;= 0
    123     * @deprecated Use {@link #builder()}, {@link Builder}, and {@link Builder#get()}
    124     */
    125    @Deprecated
    126    public ChunkedOutputStream(final OutputStream stream, final int chunkSize) {
    127        super(stream);
    128        if (chunkSize <= 0) {
    129            throw new IllegalArgumentException("chunkSize <= 0");
    130        }
    131        this.chunkSize = chunkSize;
    132    }
    133
    134    int getChunkSize() {
    135        return chunkSize;
    136    }
    137
    138    /**
    139     * Writes the data buffer in chunks to the underlying stream
    140     *
    141     * @param data      the data to write
    142     * @param srcOffset the offset
    143     * @param length    the length of data to write
    144     *
    145     * @throws IOException if an I/O error occurs.
    146     */
    147    @Override
    148    public void write(final byte[] data, final int srcOffset, final int length) throws IOException {
    149        int bytes = length;
    150        int dstOffset = srcOffset;
    151        while (bytes > 0) {
    152            final int chunk = Math.min(bytes, chunkSize);
    153            out.write(data, dstOffset, chunk);
    154            bytes -= chunk;
    155            dstOffset += chunk;
    156        }
    157    }
    158
    159}