package railo.commons.lang;
import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.io.Writer;
/**
* class to handle characters, similar to StringBuffer, but dont copy big blocks of char arrays.
*/
public class CharBuffer {
private final static int BLOCK_LENGTH = 1024;
private char buffer[];
private int pos=0;
private int length=0;
private final Entity root=new Entity(null);
private Entity curr=root;
/**
* default constructor
*/
public CharBuffer() {
this(BLOCK_LENGTH);
}
/**
* constructor with size of the buffer
* @param size
*/
public CharBuffer(int size) {
buffer = new char[size];
}
public void append(char c) {
append(new char[]{c});
}
/**
* method to appennd a charr array to the buffer
* @param c char array to append
*/
public void append(char c[]) {
int maxlength=buffer.length-pos;
if(c.length<maxlength) {
System.arraycopy(c, 0, buffer, pos, c.length);
pos+=c.length;
}
else {
System.arraycopy(c, 0, buffer, pos, maxlength);
curr.next=new Entity(buffer);
curr=curr.next;
length+=buffer.length;
buffer=new char[(buffer.length>c.length-maxlength)?buffer.length:c.length-maxlength];
if(c.length>maxlength) {
System.arraycopy(c, maxlength, buffer, 0, c.length-maxlength);
pos=c.length-maxlength;
}
else {
pos=0;
}
}
}
/**
* method to append a part of a char array
* @param c char array to get part from
* @param off start index on the char array
* @param len length of the sequenz to get from array
*/
public void append(char c[], int off, int len) {
int restLength=buffer.length-pos;
if(len<restLength) {
System.arraycopy(c, off, buffer, pos, len);
pos+=len;
}
else {
System.arraycopy(c, off, buffer, pos, restLength);
curr.next=new Entity(buffer);
curr=curr.next;
length+=buffer.length;
buffer=new char[(buffer.length>len-restLength)?buffer.length:len-restLength];
System.arraycopy(c, off+restLength, buffer, 0, len-restLength);
pos=len-restLength;
}
}
/**
* Method to append a string to char buffer
* @param str String to append
*/
public void append(String str) {
if(str==null)return;
int restLength=buffer.length-pos;
if(str.length()<restLength) {
str.getChars(0,str.length(),buffer,pos);
pos+=str.length();
}
else {
str.getChars(0,restLength,buffer,pos);
curr.next=new Entity(buffer);
curr=curr.next;
length+=buffer.length;
buffer=new char[(buffer.length>str.length()-restLength)?buffer.length:str.length()-restLength];
str.getChars(restLength,str.length(),buffer,0);
pos=str.length()-restLength;
}
}
/**
* method to append a part of a String
* @param str string to get part from
* @param off start index on the string
* @param len length of the sequenz to get from string
*/
public void append(String str, int off, int len) {
int restLength=buffer.length-pos;
if(len<restLength) {
str.getChars(off,off+len,buffer,pos);
pos+=len;
}
else {
str.getChars(off,off+restLength,buffer,pos);
curr.next=new Entity(buffer);
curr=curr.next;
length+=buffer.length;
buffer=new char[(buffer.length>len-restLength)?buffer.length:len-restLength];
str.getChars(off+restLength,off+len,buffer,0);
pos=len-restLength;
}
}
/**
* method to writeout content of the char buffer in a writer,
* this is faster than get char array with (toCharArray()) and write this
in writer.
* @param writer writer to write inside
* @throws IOException
*/
public void writeOut(Writer writer) throws IOException {
Entity e=root;
while(e.next!=null) {
e=e.next;
writer.write(e.data);
}
writer.write(buffer, 0, pos);
}
public void writeOut(OutputStream os, String charset) throws IOException {
Entity e=root;
while(e.next!=null) {
e=e.next;
os.write(new String(e.data).getBytes(charset));
}
os.write(new String(buffer, 0, pos).getBytes(charset));
}
/**
* return content of the Char Buffer as char array
* @return char array
*/
public char[] toCharArray() {
Entity e=root;
char[] chrs=new char[size()];
int off=0;
while(e.next!=null) {
e=e.next;
System.arraycopy(e.data,0,chrs,off,e.data.length);
off+=e.data.length;
}
System.arraycopy(buffer,0,chrs,off,pos);
return chrs;
}
@Override
public String toString() {
return new String(toCharArray());
}
/**
* clear the content of the buffer
*/
public void clear() {
if(size()==0)return;
buffer = new char[buffer.length];
root.next=null;
pos = 0;
length=0;
curr=root;
}
/**
* @return returns the size of the content of the buffer
*/
public int size() {
return length+pos;
}
private class Entity {
private char[] data;
private Entity next;
private Entity(char[] data) {
this.data=data;
}
}
public byte[] getBytes(String characterEncoding) throws UnsupportedEncodingException {
return toString().getBytes(characterEncoding);
}
/*public static void main(String[] args) {
CharBuffer cb=new CharBuffer(3);
cb.append("12");
cb.append("34");
cb.append("5");
cb.append("6");
cb.append("7");
cb.append("890-");
cb.append("1234567890-1234567890-");
cb=new CharBuffer(3);
cb.append("12",0,2);
cb.append("34",0,2);
cb.append("5",0,1);
cb.append("xxx6ggg",3,1);
cb.append("7zzz",0,1);
cb.append("890-",0,4);
cb.append("1234567890-1234567890-",0,22);
//System.out.println(cb+"->"+cb.size());
cb=new CharBuffer(3);
cb.append(new char[]{'1','2'});
cb.append(new char[]{'3','4'});
cb.append(new char[]{'5'});
cb.append(new char[]{'6'});
cb.append(new char[]{'7'});
cb.append(new char[]{'8','9','0','-'});
cb.append(new char[]{'1','2','3','4','5','6','7','8','9','0','-','1','2','3','4','5','6','7','8','9','0','-'});
System.out.println(cb+"->"+cb.size());
cb=new CharBuffer(3);
cb.append(new char[]{'X','1','2','X'},1,2);
cb.append(new char[]{'3','4'},0,2);
cb.append(new char[]{'5'},0,1);
cb.append(new char[]{'6'},0,1);
cb.append(new char[]{'7'},0,1);
cb.append(new char[]{'8','9','0','-'},0,4);
cb.append(new char[]{'1','2','3','4','5','6','7','8','9','0','-','1','2','3','4','5','6','7','8','9','0','-'},0,22);
System.out.println(cb+"->"+cb.size());
}*/
}