/*
* 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 java.io;
import java.util.Arrays;
import libcore.io.Streams;
/**
* Wraps an existing {@link InputStream} and counts the line terminators
* encountered while reading the data. Line numbering starts at 0. Recognized
* line terminator sequences are {@code '\r'}, {@code '\n'} and {@code "\r\n"}.
* When using {@code read}, line terminator sequences are always translated into
* {@code '\n'}.
*
* @deprecated Use {@link LineNumberReader} instead.
*/
@Deprecated
public class LineNumberInputStream extends FilterInputStream {
private int lineNumber;
private int markedLineNumber = -1;
private int lastChar = -1;
private int markedLastChar;
/**
* Constructs a new {@code LineNumberInputStream} on the {@link InputStream}
* {@code in}. Line numbers are counted for all data read from this stream.
*
* <p><strong>Warning:</strong> passing a null source creates an invalid
* {@code LineNumberInputStream}. All operations on such a stream will fail.
*
* @param in
* The non-null input stream to count line numbers.
*/
public LineNumberInputStream(InputStream in) {
super(in);
}
/**
* {@inheritDoc}
*
* <p>Note that the source stream may just be a sequence of {@code "\r\n"} bytes
* which are converted into {@code '\n'} by this stream. Therefore,
* {@code available} returns only {@code in.available() / 2} bytes as
* result.
*/
@Override
public int available() throws IOException {
return in.available() / 2 + (lastChar == -1 ? 0 : 1);
}
/**
* Returns the current line number for this stream. Numbering starts at 0.
*
* @return the current line number.
*/
public int getLineNumber() {
return lineNumber;
}
/**
* Sets a mark position in this stream. The parameter {@code readlimit}
* indicates how many bytes can be read before the mark is invalidated.
* Sending {@code reset()} will reposition this stream back to the marked
* position, provided that {@code readlimit} has not been surpassed.
* The line number count will also be reset to the last marked
* line number count.
* <p>
* This implementation sets a mark in the filtered stream.
*
* @param readlimit
* the number of bytes that can be read from this stream before
* the mark is invalidated.
* @see #markSupported()
* @see #reset()
*/
@Override
public void mark(int readlimit) {
in.mark(readlimit);
markedLineNumber = lineNumber;
markedLastChar = lastChar;
}
/**
* Reads a single byte from the filtered stream and returns it as an integer
* in the range from 0 to 255. Returns -1 if the end of this stream has been
* reached.
* <p>
* The line number count is incremented if a line terminator is encountered.
* Recognized line terminator sequences are {@code '\r'}, {@code '\n'} and
* {@code "\r\n"}. Line terminator sequences are always translated into
* {@code '\n'}.
*
* @return the byte read or -1 if the end of the filtered stream has been
* reached.
* @throws IOException
* if the stream is closed or another IOException occurs.
*/
@SuppressWarnings("fallthrough")
@Override
public int read() throws IOException {
int currentChar = lastChar;
if (currentChar == -1) {
currentChar = in.read();
} else {
lastChar = -1;
}
switch (currentChar) {
case '\r':
currentChar = '\n';
lastChar = in.read();
if (lastChar == '\n') {
lastChar = -1;
}
// fall through
case '\n':
lineNumber++;
}
return currentChar;
}
/**
* Reads up to {@code byteCount} bytes from the filtered stream and stores
* them in the byte array {@code buffer} starting at {@code byteOffset}.
* Returns the number of bytes actually read or -1 if no bytes have been
* read and the end of this stream has been reached.
*
* <p>The line number count is incremented if a line terminator is encountered.
* Recognized line terminator sequences are {@code '\r'}, {@code '\n'} and
* {@code "\r\n"}. Line terminator sequences are always translated into
* {@code '\n'}.
*
* @throws IndexOutOfBoundsException
* if {@code byteOffset < 0 || byteCount < 0 || byteOffset + byteCount > buffer.length}.
* @throws IOException
* if this stream is closed or another IOException occurs.
* @throws NullPointerException
* if {@code buffer == null}.
*/
@Override
public int read(byte[] buffer, int byteOffset, int byteCount) throws IOException {
Arrays.checkOffsetAndCount(buffer.length, byteOffset, byteCount);
for (int i = 0; i < byteCount; ++i) {
int currentChar;
try {
currentChar = read();
} catch (IOException e) {
if (i != 0) {
return i;
}
throw e;
}
if (currentChar == -1) {
return i == 0 ? -1 : i;
}
buffer[byteOffset + i] = (byte) currentChar;
}
return byteCount;
}
/**
* Resets this stream to the last marked location. It also resets the line
* count to what is was when this stream was marked.
*
* @throws IOException
* if this stream is already closed, no mark has been set or the
* mark is no longer valid because more than {@code readlimit}
* bytes have been read since setting the mark.
* @see #mark(int)
* @see #markSupported()
*/
@Override
public void reset() throws IOException {
in.reset();
lineNumber = markedLineNumber;
lastChar = markedLastChar;
}
/**
* Sets the line number of this stream to the specified
* {@code lineNumber}. Note that this may have side effects on the
* line number associated with the last marked position.
*
* @param lineNumber
* the new lineNumber value.
* @see #mark(int)
* @see #reset()
*/
public void setLineNumber(int lineNumber) {
this.lineNumber = lineNumber;
}
/**
* Skips {@code count} number of bytes in this stream. Subsequent
* calls to {@code read} will not return these bytes unless {@code reset} is
* used. This implementation skips {@code byteCount} bytes in the
* filtered stream and increments the line number count whenever line
* terminator sequences are skipped.
*
* @param byteCount
* the number of bytes to skip.
* @return the number of bytes actually skipped.
* @throws IOException
* if this stream is closed or another IOException occurs.
* @see #mark(int)
* @see #read()
* @see #reset()
*/
@Override
public long skip(long byteCount) throws IOException {
return Streams.skipByReading(this, byteCount);
}
}