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/*
* de.unkrig.commons - A general-purpose Java class library
*
* Copyright (c) 2013, Arno Unkrig
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
* following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the
* following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
* following disclaimer in the documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
package de.unkrig.commons.io;
import java.io.FilterReader;
import java.io.IOException;
import java.io.Reader;
import de.unkrig.commons.nullanalysis.NotNullByDefault;
/**
* A {@link FilterReader} that counts characters and line breaks in the stream. As usual, a line break is either
* a {@code '\r'}, a {@code '\n'}, or a sequence {@code "\r\n"}.
*
* @see #offset()
* @see #lineNumber()
* @see #columnNumber()
*/
@NotNullByDefault(false) public
class CountingReader extends FilterReader {
private int offset, lineNumber = 1, columnNumber;
private boolean crPending;
public CountingReader(Reader in) { super(in); }
/**
* @return The number of characters read so far
*/
public int offset() { return this.offset; }
/**
* Returns the line number of the previously read character, or '1' if no character has been read
* yet.
*
* If the previously read character is CR or LF, then the result is the number of the line
* following the line separator.
*/
public int lineNumber() { return this.lineNumber; }
/**
* Returns the column number of the previously read character, or '0' if no character has been read
* yet. The column number of the first character in a line is '1'.
*
* If the previously read character is CR or LF, then the result is '0'.
*/
public int columnNumber() { return this.columnNumber; }
@Override public int
read() throws IOException {
int c = super.read();
if (c == -1) return -1;
this.offset++;
if (this.crPending) {
this.crPending = false;
if (c == '\n') return c;
}
if (c == '\r' || c == '\n') {
this.lineNumber++;
this.columnNumber = 0;
if (c == '\r') this.crPending = true;
} else {
this.columnNumber++;
}
return c;
}
@Override public int
read(char[] cbuf, int off, int len) throws IOException {
if (len <= 0) return 0;
int c = this.read();
if (c == -1) return -1;
int n = 1; // SUPPRESS CHECKSTYLE UsageDistance
for (;;) {
cbuf[off++] = (char) c;
if (--len == 0) return n;
c = this.read();
if (c == -1) return n;
n++;
}
}
}