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/*
* 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.solr.internal.csv;
/**
* A simple StringBuffer replacement that aims to reduce copying as much as possible. The buffer
* grows as necessary. This class is not thread safe.
*/
public class CharBuffer {
private char[] c;
/**
* Actually used number of characters in the array. It is also the index at which a new character
* will be inserted into c.
*/
private int length;
/** Creates a new CharBuffer with an initial capacity of 32 characters. */
public CharBuffer() {
this(32);
}
/** Creates a new CharBuffer with an initial capacity of length characters. */
public CharBuffer(final int length) {
if (length == 0) {
throw new IllegalArgumentException("Can't create an empty CharBuffer");
}
this.c = new char[length];
}
/** Empties the buffer. The capacity still remains the same, so no memory is freed. */
public void clear() {
length = 0;
}
/**
* Returns the number of characters in the buffer.
*
* @return the number of characters
*/
public int length() {
return length;
}
/**
* Returns the current capacity of the buffer.
*
* @return the maximum number of characters that can be stored in this buffer without resizing it.
*/
public int capacity() {
return c.length;
}
/**
* Appends the contents of cb to the end of this CharBuffer.
*
* @param cb the CharBuffer to append or null
*/
public void append(final CharBuffer cb) {
if (cb == null) {
return;
}
provideCapacity(length + cb.length);
System.arraycopy(cb.c, 0, c, length, cb.length);
length += cb.length;
}
/**
* Appends s to the end of this CharBuffer. This method involves copying the new data
* once!
*
* @param s the String to append or null
*/
public void append(final String s) {
if (s == null) {
return;
}
append(s.toCharArray());
}
/**
* Appends sb to the end of this CharBuffer. This method involves copying the new
* data once!
*
* @param sb the StringBuffer to append or null
*/
@Deprecated
@SuppressWarnings("JdkObsolete")
public void append(final StringBuffer sb) {
if (sb == null) {
return;
}
provideCapacity(length + sb.length());
sb.getChars(0, sb.length(), c, length);
length += sb.length();
}
/**
* Appends sb to the end of this CharBuffer. This method involves copying the new
* data once!
*
* @param sb the StringBuffer to append or null
*/
public void append(final StringBuilder sb) {
if (sb == null) {
return;
}
provideCapacity(length + sb.length());
sb.getChars(0, sb.length(), c, length);
length += sb.length();
}
/**
* Appends data to the end of this CharBuffer. This method involves copying the new
* data once!
*
* @param data the char[] to append or null
*/
public void append(final char[] data) {
if (data == null) {
return;
}
provideCapacity(length + data.length);
System.arraycopy(data, 0, c, length, data.length);
length += data.length;
}
/**
* Appends a single character to the end of this CharBuffer. This method involves copying the new
* data once!
*
* @param data the char to append
*/
public void append(final char data) {
provideCapacity(length + 1);
c[length] = data;
length++;
}
/**
* Shrinks the capacity of the buffer to the current length if necessary. This method involves
* copying the data once!
*/
public void shrink() {
if (c.length == length) {
return;
}
char[] newc = new char[length];
System.arraycopy(c, 0, newc, 0, length);
c = newc;
}
/** Removes trailing whitespace. */
public void trimTrailingWhitespace() {
while (length > 0 && Character.isWhitespace(c[length - 1])) {
length--;
}
}
/**
* Returns the contents of the buffer as a char[]. The returned array may be the internal array of
* the buffer, so the caller must take care when modifying it. This method allows to avoid copying
* if the caller knows the exact capacity before.
*/
public char[] getCharacters() {
if (c.length == length) {
return c;
}
char[] chars = new char[length];
System.arraycopy(c, 0, chars, 0, length);
return chars;
}
/** Returns the character at the specified position. */
public char charAt(int pos) {
return c[pos];
}
/**
* Converts the contents of the buffer into a StringBuffer. This method involves copying the new
* data once!
*/
@Override
public String toString() {
return new String(c, 0, length);
}
/** Copies the data into a new array of at least capacity size. */
public void provideCapacity(final int capacity) {
if (c.length >= capacity) {
return;
}
int newcapacity = ((capacity * 3) >> 1) + 1;
char[] newc = new char[newcapacity];
System.arraycopy(c, 0, newc, 0, length);
c = newc;
}
}