michael@0: /*
michael@0:  * ====================================================================
michael@0:  * Licensed to the Apache Software Foundation (ASF) under one
michael@0:  * or more contributor license agreements.  See the NOTICE file
michael@0:  * distributed with this work for additional information
michael@0:  * regarding copyright ownership.  The ASF licenses this file
michael@0:  * to you under the Apache License, Version 2.0 (the
michael@0:  * "License"); you may not use this file except in compliance
michael@0:  * with the License.  You may obtain a copy of the License at
michael@0:  *
michael@0:  *   http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing,
michael@0:  * software distributed under the License is distributed on an
michael@0:  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
michael@0:  * KIND, either express or implied.  See the License for the
michael@0:  * specific language governing permissions and limitations
michael@0:  * under the License.
michael@0:  * ====================================================================
michael@0:  *
michael@0:  * This software consists of voluntary contributions made by many
michael@0:  * individuals on behalf of the Apache Software Foundation.  For more
michael@0:  * information on the Apache Software Foundation, please see
michael@0:  * <http://www.apache.org/>.
michael@0:  *
michael@0:  */
michael@0: 
michael@0: package ch.boye.httpclientandroidlib.util;
michael@0: 
michael@0: import java.io.Serializable;
michael@0: 
michael@0: /**
michael@0:  * A resizable byte array.
michael@0:  *
michael@0:  * @since 4.0
michael@0:  */
michael@0: public final class ByteArrayBuffer implements Serializable {
michael@0: 
michael@0:     private static final long serialVersionUID = 4359112959524048036L;
michael@0: 
michael@0:     private byte[] buffer;
michael@0:     private int len;
michael@0: 
michael@0:     /**
michael@0:      * Creates an instance of {@link ByteArrayBuffer} with the given initial
michael@0:      * capacity.
michael@0:      *
michael@0:      * @param capacity the capacity
michael@0:      */
michael@0:     public ByteArrayBuffer(int capacity) {
michael@0:         super();
michael@0:         if (capacity < 0) {
michael@0:             throw new IllegalArgumentException("Buffer capacity may not be negative");
michael@0:         }
michael@0:         this.buffer = new byte[capacity];
michael@0:     }
michael@0: 
michael@0:     private void expand(int newlen) {
michael@0:         byte newbuffer[] = new byte[Math.max(this.buffer.length << 1, newlen)];
michael@0:         System.arraycopy(this.buffer, 0, newbuffer, 0, this.len);
michael@0:         this.buffer = newbuffer;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Appends <code>len</code> bytes to this buffer from the given source
michael@0:      * array starting at index <code>off</code>. The capacity of the buffer
michael@0:      * is increased, if necessary, to accommodate all <code>len</code> bytes.
michael@0:      *
michael@0:      * @param   b        the bytes to be appended.
michael@0:      * @param   off      the index of the first byte to append.
michael@0:      * @param   len      the number of bytes to append.
michael@0:      * @throws IndexOutOfBoundsException if <code>off</code> if out of
michael@0:      * range, <code>len</code> is negative, or
michael@0:      * <code>off</code> + <code>len</code> is out of range.
michael@0:      */
michael@0:     public void append(final byte[] b, int off, int len) {
michael@0:         if (b == null) {
michael@0:             return;
michael@0:         }
michael@0:         if ((off < 0) || (off > b.length) || (len < 0) ||
michael@0:                 ((off + len) < 0) || ((off + len) > b.length)) {
michael@0:             throw new IndexOutOfBoundsException("off: "+off+" len: "+len+" b.length: "+b.length);
michael@0:         }
michael@0:         if (len == 0) {
michael@0:             return;
michael@0:         }
michael@0:         int newlen = this.len + len;
michael@0:         if (newlen > this.buffer.length) {
michael@0:             expand(newlen);
michael@0:         }
michael@0:         System.arraycopy(b, off, this.buffer, this.len, len);
michael@0:         this.len = newlen;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Appends <code>b</code> byte to this buffer. The capacity of the buffer
michael@0:      * is increased, if necessary, to accommodate the additional byte.
michael@0:      *
michael@0:      * @param   b        the byte to be appended.
michael@0:      */
michael@0:     public void append(int b) {
michael@0:         int newlen = this.len + 1;
michael@0:         if (newlen > this.buffer.length) {
michael@0:             expand(newlen);
michael@0:         }
michael@0:         this.buffer[this.len] = (byte)b;
michael@0:         this.len = newlen;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Appends <code>len</code> chars to this buffer from the given source
michael@0:      * array starting at index <code>off</code>. The capacity of the buffer
michael@0:      * is increased if necessary to accommodate all <code>len</code> chars.
michael@0:      * <p>
michael@0:      * The chars are converted to bytes using simple cast.
michael@0:      *
michael@0:      * @param   b        the chars to be appended.
michael@0:      * @param   off      the index of the first char to append.
michael@0:      * @param   len      the number of bytes to append.
michael@0:      * @throws IndexOutOfBoundsException if <code>off</code> if out of
michael@0:      * range, <code>len</code> is negative, or
michael@0:      * <code>off</code> + <code>len</code> is out of range.
michael@0:      */
michael@0:     public void append(final char[] b, int off, int len) {
michael@0:         if (b == null) {
michael@0:             return;
michael@0:         }
michael@0:         if ((off < 0) || (off > b.length) || (len < 0) ||
michael@0:                 ((off + len) < 0) || ((off + len) > b.length)) {
michael@0:             throw new IndexOutOfBoundsException("off: "+off+" len: "+len+" b.length: "+b.length);
michael@0:         }
michael@0:         if (len == 0) {
michael@0:             return;
michael@0:         }
michael@0:         int oldlen = this.len;
michael@0:         int newlen = oldlen + len;
michael@0:         if (newlen > this.buffer.length) {
michael@0:             expand(newlen);
michael@0:         }
michael@0:         for (int i1 = off, i2 = oldlen; i2 < newlen; i1++, i2++) {
michael@0:             this.buffer[i2] = (byte) b[i1];
michael@0:         }
michael@0:         this.len = newlen;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Appends <code>len</code> chars to this buffer from the given source
michael@0:      * char array buffer starting at index <code>off</code>. The capacity
michael@0:      * of the buffer is increased if necessary to accommodate all
michael@0:      * <code>len</code> chars.
michael@0:      * <p>
michael@0:      * The chars are converted to bytes using simple cast.
michael@0:      *
michael@0:      * @param   b        the chars to be appended.
michael@0:      * @param   off      the index of the first char to append.
michael@0:      * @param   len      the number of bytes to append.
michael@0:      * @throws IndexOutOfBoundsException if <code>off</code> if out of
michael@0:      * range, <code>len</code> is negative, or
michael@0:      * <code>off</code> + <code>len</code> is out of range.
michael@0:      */
michael@0:     public void append(final CharArrayBuffer b, int off, int len) {
michael@0:         if (b == null) {
michael@0:             return;
michael@0:         }
michael@0:         append(b.buffer(), off, len);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Clears content of the buffer. The underlying byte array is not resized.
michael@0:      */
michael@0:     public void clear() {
michael@0:         this.len = 0;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Converts the content of this buffer to an array of bytes.
michael@0:      *
michael@0:      * @return byte array
michael@0:      */
michael@0:     public byte[] toByteArray() {
michael@0:         byte[] b = new byte[this.len];
michael@0:         if (this.len > 0) {
michael@0:             System.arraycopy(this.buffer, 0, b, 0, this.len);
michael@0:         }
michael@0:         return b;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Returns the <code>byte</code> value in this buffer at the specified
michael@0:      * index. The index argument must be greater than or equal to
michael@0:      * <code>0</code>, and less than the length of this buffer.
michael@0:      *
michael@0:      * @param      i   the index of the desired byte value.
michael@0:      * @return     the byte value at the specified index.
michael@0:      * @throws     IndexOutOfBoundsException  if <code>index</code> is
michael@0:      *             negative or greater than or equal to {@link #length()}.
michael@0:      */
michael@0:     public int byteAt(int i) {
michael@0:         return this.buffer[i];
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Returns the current capacity. The capacity is the amount of storage
michael@0:      * available for newly appended bytes, beyond which an allocation
michael@0:      * will occur.
michael@0:      *
michael@0:      * @return  the current capacity
michael@0:      */
michael@0:     public int capacity() {
michael@0:         return this.buffer.length;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Returns the length of the buffer (byte count).
michael@0:      *
michael@0:      * @return  the length of the buffer
michael@0:      */
michael@0:     public int length() {
michael@0:         return this.len;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Ensures that the capacity is at least equal to the specified minimum.
michael@0:      * If the current capacity is less than the argument, then a new internal
michael@0:      * array is allocated with greater capacity. If the <code>required</code>
michael@0:      * argument is non-positive, this method takes no action.
michael@0:      *
michael@0:      * @param   required   the minimum required capacity.
michael@0:      *
michael@0:      * @since 4.1
michael@0:      */
michael@0:     public void ensureCapacity(int required) {
michael@0:         if (required <= 0) {
michael@0:             return;
michael@0:         }
michael@0:         int available = this.buffer.length - this.len;
michael@0:         if (required > available) {
michael@0:             expand(this.len + required);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Returns reference to the underlying byte array.
michael@0:      *
michael@0:      * @return the byte array.
michael@0:      */
michael@0:     public byte[] buffer() {
michael@0:         return this.buffer;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Sets the length of the buffer. The new length value is expected to be
michael@0:      * less than the current capacity and greater than or equal to
michael@0:      * <code>0</code>.
michael@0:      *
michael@0:      * @param      len   the new length
michael@0:      * @throws     IndexOutOfBoundsException  if the
michael@0:      *               <code>len</code> argument is greater than the current
michael@0:      *               capacity of the buffer or less than <code>0</code>.
michael@0:      */
michael@0:     public void setLength(int len) {
michael@0:         if (len < 0 || len > this.buffer.length) {
michael@0:             throw new IndexOutOfBoundsException("len: "+len+" < 0 or > buffer len: "+this.buffer.length);
michael@0:         }
michael@0:         this.len = len;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Returns <code>true</code> if this buffer is empty, that is, its
michael@0:      * {@link #length()} is equal to <code>0</code>.
michael@0:      * @return <code>true</code> if this buffer is empty, <code>false</code>
michael@0:      *   otherwise.
michael@0:      */
michael@0:     public boolean isEmpty() {
michael@0:         return this.len == 0;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Returns <code>true</code> if this buffer is full, that is, its
michael@0:      * {@link #length()} is equal to its {@link #capacity()}.
michael@0:      * @return <code>true</code> if this buffer is full, <code>false</code>
michael@0:      *   otherwise.
michael@0:      */
michael@0:     public boolean isFull() {
michael@0:         return this.len == this.buffer.length;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Returns the index within this buffer of the first occurrence of the
michael@0:      * specified byte, starting the search at the specified
michael@0:      * <code>beginIndex</code> and finishing at <code>endIndex</code>.
michael@0:      * If no such byte occurs in this buffer within the specified bounds,
michael@0:      * <code>-1</code> is returned.
michael@0:      * <p>
michael@0:      * There is no restriction on the value of <code>beginIndex</code> and
michael@0:      * <code>endIndex</code>. If <code>beginIndex</code> is negative,
michael@0:      * it has the same effect as if it were zero. If <code>endIndex</code> is
michael@0:      * greater than {@link #length()}, it has the same effect as if it were
michael@0:      * {@link #length()}. If the <code>beginIndex</code> is greater than
michael@0:      * the <code>endIndex</code>, <code>-1</code> is returned.
michael@0:      *
michael@0:      * @param   b            the byte to search for.
michael@0:      * @param   beginIndex   the index to start the search from.
michael@0:      * @param   endIndex     the index to finish the search at.
michael@0:      * @return  the index of the first occurrence of the byte in the buffer
michael@0:      *   within the given bounds, or <code>-1</code> if the byte does
michael@0:      *   not occur.
michael@0:      *
michael@0:      * @since 4.1
michael@0:      */
michael@0:     public int indexOf(byte b, int beginIndex, int endIndex) {
michael@0:         if (beginIndex < 0) {
michael@0:             beginIndex = 0;
michael@0:         }
michael@0:         if (endIndex > this.len) {
michael@0:             endIndex = this.len;
michael@0:         }
michael@0:         if (beginIndex > endIndex) {
michael@0:             return -1;
michael@0:         }
michael@0:         for (int i = beginIndex; i < endIndex; i++) {
michael@0:             if (this.buffer[i] == b) {
michael@0:                 return i;
michael@0:             }
michael@0:         }
michael@0:         return -1;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Returns the index within this buffer of the first occurrence of the
michael@0:      * specified byte, starting the search at <code>0</code> and finishing
michael@0:      * at {@link #length()}. If no such byte occurs in this buffer within
michael@0:      * those bounds, <code>-1</code> is returned.
michael@0:      *
michael@0:      * @param   b   the byte to search for.
michael@0:      * @return  the index of the first occurrence of the byte in the
michael@0:      *   buffer, or <code>-1</code> if the byte does not occur.
michael@0:      *
michael@0:      * @since 4.1
michael@0:      */
michael@0:     public int indexOf(byte b) {
michael@0:         return indexOf(b, 0, this.len);
michael@0:     }
michael@0: }