    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.BufferedInputStream;
    020import java.io.IOException;
    021import java.io.InputStream;
    022import java.io.OutputStream;
    023
    024import org.apache.commons.io.build.AbstractOrigin;
    025import org.apache.commons.io.build.AbstractStreamBuilder;
    026import org.apache.commons.io.function.Uncheck;
    027import org.apache.commons.io.input.UnsynchronizedByteArrayInputStream;
    028
    029/**
    030 * Implements a version of {@link AbstractByteArrayOutputStream} <strong>without</strong> any concurrent thread safety.
    031 * <p>
    032 * To build an instance, use {@link Builder}.
    033 * </p>
    034 *
    035 * @see Builder
    036 * @since 2.7
    037 */
    038//@NotThreadSafe
    039public final class UnsynchronizedByteArrayOutputStream extends AbstractByteArrayOutputStream {
    040
    041    // @formatter:off
    042    /**
    043     * Builds a new {@link UnsynchronizedByteArrayOutputStream}.
    044     *
    045     * <p>
    046     * Using File IO:
    047     * </p>
    048     * <pre>{@code
    049     * UnsynchronizedByteArrayOutputStream s = UnsynchronizedByteArrayOutputStream.builder()
    050     *   .setBufferSize(8192)
    051     *   .get();}
    052     * </pre>
    053     * <p>
    054     * Using NIO Path:
    055     * </p>
    056     * <pre>{@code
    057     * UnsynchronizedByteArrayOutputStream s = UnsynchronizedByteArrayOutputStream.builder()
    058     *   .setBufferSize(8192)
    059     *   .get();}
    060     * </pre>
    061     *
    062     * @see #get()
    063     */
    064    // @formatter:on
    065    public static class Builder extends AbstractStreamBuilder<UnsynchronizedByteArrayOutputStream, Builder> {
    066
    067        /**
    068         * Builds a new {@link UnsynchronizedByteArrayOutputStream}.
    069         *
    070         * <p>
    071         * This builder use the following aspects:
    072         * </p>
    073         * <ul>
    074         * <li>{@link #getBufferSize()}</li>
    075         * </ul>
    076         *
    077         * @return a new instance.
    078         * @see AbstractOrigin#getByteArray()
    079         */
    080        @Override
    081        public UnsynchronizedByteArrayOutputStream get() {
    082            return new UnsynchronizedByteArrayOutputStream(getBufferSize());
    083        }
    084
    085    }
    086
    087    /**
    088     * Constructs a new {@link Builder}.
    089     *
    090     * @return a new {@link Builder}.
    091     */
    092    public static Builder builder() {
    093        return new Builder();
    094    }
    095
    096    /**
    097     * Fetches entire contents of an {@link InputStream} and represent same data as result InputStream.
    098     * <p>
    099     * This method is useful where,
    100     * </p>
    101     * <ul>
    102     * <li>Source InputStream is slow.</li>
    103     * <li>It has network resources associated, so we cannot keep it open for long time.</li>
    104     * <li>It has network timeout associated.</li>
    105     * </ul>
    106     * It can be used in favor of {@link #toByteArray()}, since it avoids unnecessary allocation and copy of byte[].<br>
    107     * This method buffers the input internally, so there is no need to use a {@link BufferedInputStream}.
    108     *
    109     * @param input Stream to be fully buffered.
    110     * @return A fully buffered stream.
    111     * @throws IOException if an I/O error occurs.
    112     */
    113    public static InputStream toBufferedInputStream(final InputStream input) throws IOException {
    114        return toBufferedInputStream(input, DEFAULT_SIZE);
    115    }
    116
    117    /**
    118     * Fetches entire contents of an {@link InputStream} and represent same data as result InputStream.
    119     * <p>
    120     * This method is useful where,
    121     * </p>
    122     * <ul>
    123     * <li>Source InputStream is slow.</li>
    124     * <li>It has network resources associated, so we cannot keep it open for long time.</li>
    125     * <li>It has network timeout associated.</li>
    126     * </ul>
    127     * It can be used in favor of {@link #toByteArray()}, since it avoids unnecessary allocation and copy of byte[].<br>
    128     * This method buffers the input internally, so there is no need to use a {@link BufferedInputStream}.
    129     *
    130     * @param input Stream to be fully buffered.
    131     * @param size the initial buffer size
    132     * @return A fully buffered stream.
    133     * @throws IOException if an I/O error occurs.
    134     */
    135    public static InputStream toBufferedInputStream(final InputStream input, final int size) throws IOException {
    136        // It does not matter if a ByteArrayOutputStream is not closed as close() is a no-op
    137        try (UnsynchronizedByteArrayOutputStream output = builder().setBufferSize(size).get()) {
    138            output.write(input);
    139            return output.toInputStream();
    140        }
    141    }
    142
    143    /**
    144     * Constructs a new byte array output stream. The buffer capacity is initially
    145     *
    146     * {@value AbstractByteArrayOutputStream#DEFAULT_SIZE} bytes, though its size increases if necessary.
    147     * @deprecated Use {@link #builder()}, {@link Builder}, and {@link Builder#get()}.
    148     */
    149    @Deprecated
    150    public UnsynchronizedByteArrayOutputStream() {
    151        this(DEFAULT_SIZE);
    152    }
    153
    154    /**
    155     * Constructs a new byte array output stream, with a buffer capacity of the specified size, in bytes.
    156     *
    157     * @param size the initial size
    158     * @throws IllegalArgumentException if size is negative
    159     * @deprecated Use {@link #builder()}, {@link Builder}, and {@link Builder#get()}. Will be private in 3.0.0.
    160     */
    161    @Deprecated
    162    public UnsynchronizedByteArrayOutputStream(final int size) {
    163        if (size < 0) {
    164            throw new IllegalArgumentException("Negative initial size: " + size);
    165        }
    166        needNewBuffer(size);
    167    }
    168
    169    /**
    170     * @see java.io.ByteArrayOutputStream#reset()
    171     */
    172    @Override
    173    public void reset() {
    174        resetImpl();
    175    }
    176
    177    @Override
    178    public int size() {
    179        return count;
    180    }
    181
    182    @Override
    183    public byte[] toByteArray() {
    184        return toByteArrayImpl();
    185    }
    186
    187    @Override
    188    public InputStream toInputStream() {
    189        // @formatter:off
    190        return toInputStream((buffer, offset, length) -> Uncheck
    191                .get(() -> UnsynchronizedByteArrayInputStream.builder()
    192                        .setByteArray(buffer)
    193                        .setOffset(offset)
    194                        .setLength(length)
    195                        .get()));
    196        // @formatter:on
    197    }
    198
    199    @Override
    200    public void write(final byte[] b, final int off, final int len) {
    201        if (off < 0 || off > b.length || len < 0 || off + len > b.length || off + len < 0) {
    202            throw new IndexOutOfBoundsException(String.format("offset=%,d, length=%,d", off, len));
    203        }
    204        if (len == 0) {
    205            return;
    206        }
    207        writeImpl(b, off, len);
    208    }
    209
    210    @Override
    211    public int write(final InputStream in) throws IOException {
    212        return writeImpl(in);
    213    }
    214
    215    @Override
    216    public void write(final int b) {
    217        writeImpl(b);
    218    }
    219
    220    @Override
    221    public void writeTo(final OutputStream out) throws IOException {
    222        writeToImpl(out);
    223    }
    224}