/*
* Copyright 2004-2009 the original author or authors.
*
* Licensed 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.compass.core.util.reader;
import java.io.Reader;
import org.compass.core.engine.RepeatableReader;
/**
* A character stream whose source is a string. Allows for
* repeatable reads from the same string.
* <p/>
* Note, this is an unsafe reader in terms of {@link IndexOutOfBoundsException}.
*
* @author kimchy
*/
public class StringReader extends Reader implements RepeatableReader {
private String str;
private int length;
private int next = 0;
private int mark = 0;
public StringReader(String s) {
this.str = s;
this.length = s.length();
}
public int read() {
if (next >= length)
return -1;
return str.charAt(next++);
}
public int read(char cbuf[], int off, int len) {
if (len == 0) {
return 0;
}
if (next >= length) {
// reset the reader for a possible next read
close();
// and return -1 to indicate no more data
return -1;
}
int n = Math.min(length - next, len);
str.getChars(next, next + n, cbuf, off);
next += n;
return n;
}
public long skip(long ns) {
if (next >= length)
return 0;
long n = Math.min(length - next, ns);
next += n;
return n;
}
public boolean ready() {
return true;
}
public boolean markSupported() {
return true;
}
public void mark(int readAheadLimit) {
if (readAheadLimit < 0) {
throw new IllegalArgumentException("Read-ahead limit < 0");
}
mark = next;
}
public void reset() {
next = mark;
}
public void close() {
next = 0;
mark = 0;
}
}