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/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch 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.elasticsearch.hadoop.util;

/*
 * This file is derived from org.elasticsearch.common.io.FastByteArrayInputStream.
 * All copyrights apply.
 * License header for that code follows:
 */

/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch 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.
 */

import java.io.InputStream;

/**
 * Taken from Elasticsearch - copy of org.elasticsearch.common.io.FastByteArrayInputStream with some enhancements,
 * mainly in allowing access to the underlying byte[] and in respecting slicing of an underlying BytesArray.
 *
 * Similar to {@link java.io.ByteArrayInputStream} just not synced.
 */
public class FastByteArrayInputStream extends InputStream {

    /**
     * An array of bytes that was provided
     * by the creator of the stream. Elements buf[0]
     * through buf[count-1] are the
     * only bytes that can ever be read from the
     * stream;  element buf[pos] is
     * the next byte to be read.
     */
    protected BytesArray data;

    /**
     * The initial starting place of the array buffer passed in to this
     * input stream.
     */
    protected int offset;

    /**
     * The index of the next character to read from the input stream buffer.
     * This value should always be nonnegative
     * and not larger than the value of count.
     * The next byte to be read from the input stream buffer
     * will be buf[pos].
     */
    protected int pos;

    /**
     * The currently marked position in the stream.
     * ByteArrayInputStream objects are marked at position zero by
     * default when constructed.  They may be marked at another
     * position within the buffer by the mark() method.
     * The current buffer position is set to this point by the
     * reset() method.
     * 

* If no mark has been set, then the value of mark is the offset * passed to the constructor (or 0 if the offset was not supplied). * * @since JDK1.1 */ protected int mark = 0; /** * The index one greater than the last valid character in the input * stream buffer. * This value should always be nonnegative * and not larger than the length of buf. * It is one greater than the position of * the last byte within buf that * can ever be read from the input stream buffer. */ protected int count; public FastByteArrayInputStream(byte[] data) { this(new BytesArray(data)); } /** * Creates a ByteArrayInputStream * so that it uses data as its * buffer array. * The buffer array is not copied. * The initial value of pos * is set to the bytes array's offset and the * initial value of count is the * logical size of the bytes array. * * @param data the input buffer. */ public FastByteArrayInputStream(BytesArray data) { this.data = data; this.pos = data.offset; this.offset = data.offset; this.count = data.offset + data.size; } /** * Reads the next byte of data from this input stream. The value * byte is returned as an int in the range * 0 to 255. If no byte is available * because the end of the stream has been reached, the value * -1 is returned. *

* This read method * cannot block. * * @return the next byte of data, or -1 if the end of the * stream has been reached. */ public int read() { return (pos < count) ? (data.bytes[pos++] & 0xff) : -1; } /** * Reads up to len bytes of data into an array of bytes * from this input stream. * If pos equals count, * then -1 is returned to indicate * end of file. Otherwise, the number k * of bytes read is equal to the smaller of * len and count-pos. * If k is positive, then bytes * buf[pos] through buf[pos+k-1] * are copied into b[off] through * b[off+k-1] in the manner performed * by System.arraycopy. The * value k is added into pos * and k is returned. *

* This read method cannot block. * * @param b the buffer into which the data is read. * @param off the start offset in the destination array b * @param len the maximum number of bytes read. * @return the total number of bytes read into the buffer, or * -1 if there is no more data because the end of * the stream has been reached. * @throws NullPointerException If b is null. * @throws IndexOutOfBoundsException If off is negative, * len is negative, or len is greater than * b.length - off */ public int read(byte b[], int off, int len) { if (b == null) { throw new NullPointerException(); } else if (off < 0 || len < 0 || len > b.length - off) { throw new IndexOutOfBoundsException(); } if (pos >= count) { return -1; } if (pos + len > count) { len = count - pos; } if (len <= 0) { return 0; } System.arraycopy(data.bytes, pos, b, off, len); pos += len; return len; } /** * Skips n bytes of input from this input stream. Fewer * bytes might be skipped if the end of the input stream is reached. * The actual number k * of bytes to be skipped is equal to the smaller * of n and count-pos. * The value k is added into pos * and k is returned. * * @param n the number of bytes to be skipped. * @return the actual number of bytes skipped. */ public long skip(long n) { if (pos + n > count) { n = count - pos; } if (n < 0) { return 0; } pos += n; return n; } /** * Returns the number of remaining bytes that can be read (or skipped over) * from this input stream. *

* The value returned is count - pos, * which is the number of bytes remaining to be read from the input buffer. * * @return the number of remaining bytes that can be read (or skipped * over) from this input stream without blocking. */ public int available() { return count - pos; } /** * @return the relative position of the stream in regards to the underlying buffer. */ public int position() { return pos - offset; } /** * Tests if this InputStream supports mark/reset. The * markSupported method of ByteArrayInputStream * always returns true. * * @since JDK1.1 */ public boolean markSupported() { return true; } /** * Set the current marked position in the stream. * ByteArrayInputStream objects are marked at position zero by * default when constructed. They may be marked at another * position within the buffer by this method. *

* If no mark has been set, then the value of the mark is the * offset passed to the constructor (or 0 if the offset was not * supplied). *

*

Note: The readAheadLimit for this class * has no meaning. * * @since JDK1.1 */ public void mark(int readAheadLimit) { mark = pos; } /** * Resets the buffer to the marked position. The marked position * is 0 unless another position was marked or an offset was specified * in the constructor. */ public void reset() { pos = mark; } /** * Closing a ByteArrayInputStream has no effect. The methods in * this class can be called after the stream has been closed without * generating an IOException. *

*/ public void close() {} public BytesArray bytes() { return data; } public void setBytes(byte[] data, int size) { this.data.bytes(data, size); } }





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