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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 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.
     *
     * 

Warning: 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} * *

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. *

* 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. *

* 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. * *

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); } }





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