android-35/java/io/BufferedReader.java - platform/prebuilts/fullsdk/sources - Git at Google

 /*
  * Copyright (C) 2014 The Android Open Source Project
  * Copyright (c) 1996, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */

 package java.io;


 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.Spliterator;
 import java.util.Spliterators;
 import java.util.stream.Stream;
 import java.util.stream.StreamSupport;

 /**
  * Reads text from a character-input stream, buffering characters so as to
  * provide for the efficient reading of characters, arrays, and lines.
  *
  * <p> The buffer size may be specified, or the default size may be used.  The
  * default is large enough for most purposes.
  *
  * <p> In general, each read request made of a Reader causes a corresponding
  * read request to be made of the underlying character or byte stream.  It is
  * therefore advisable to wrap a BufferedReader around any Reader whose read()
  * operations may be costly, such as FileReaders and InputStreamReaders.  For
  * example,
  *
  * <pre>
  * BufferedReader in
  *   = new BufferedReader(new FileReader("foo.in"));
  * </pre>
  *
  * will buffer the input from the specified file.  Without buffering, each
  * invocation of read() or readLine() could cause bytes to be read from the
  * file, converted into characters, and then returned, which can be very
  * inefficient.
  *
  * <p> Programs that use DataInputStreams for textual input can be localized by
  * replacing each DataInputStream with an appropriate BufferedReader.
  *
  * @see FileReader
  * @see InputStreamReader
  * @see java.nio.file.Files#newBufferedReader
  *
  * @author      Mark Reinhold
  * @since       1.1
  */

 public class BufferedReader extends Reader {

     private Reader in;

     private char cb[];
     private int nChars, nextChar;

     private static final int INVALIDATED = -2;
     private static final int UNMARKED = -1;
     private int markedChar = UNMARKED;
     private int readAheadLimit = 0; /* Valid only when markedChar > 0 */

     /** If the next character is a line feed, skip it */
     private boolean skipLF = false;

     /** The skipLF flag when the mark was set */
     private boolean markedSkipLF = false;

     private static int defaultCharBufferSize = 8192;
     private static int defaultExpectedLineLength = 80;

     /**
      * Creates a buffering character-input stream that uses an input buffer of
      * the specified size.
      *
      * @param  in   A Reader
      * @param  sz   Input-buffer size
      *
      * @exception  IllegalArgumentException  If {@code sz <= 0}
      */
     public BufferedReader(Reader in, int sz) {
         super(in);
         if (sz <= 0)
             throw new IllegalArgumentException("Buffer size <= 0");
         this.in = in;
         cb = new char[sz];
         nextChar = nChars = 0;
     }

     /**
      * Creates a buffering character-input stream that uses a default-sized
      * input buffer.
      *
      * @param  in   A Reader
      */
     public BufferedReader(Reader in) {
         this(in, defaultCharBufferSize);
     }

     /** Checks to make sure that the stream has not been closed */
     private void ensureOpen() throws IOException {
         if (in == null)
             throw new IOException("Stream closed");
     }

     /**
      * Fills the input buffer, taking the mark into account if it is valid.
      */
     private void fill() throws IOException {
         int dst;
         if (markedChar <= UNMARKED) {
             /* No mark */
             dst = 0;
         } else {
             /* Marked */
             int delta = nextChar - markedChar;
             if (delta >= readAheadLimit) {
                 /* Gone past read-ahead limit: Invalidate mark */
                 markedChar = INVALIDATED;
                 readAheadLimit = 0;
                 dst = 0;
             } else {
                 if (readAheadLimit <= cb.length) {
                     /* Shuffle in the current buffer */
                     System.arraycopy(cb, markedChar, cb, 0, delta);
                     markedChar = 0;
                     dst = delta;
                 } else {
                     /* Reallocate buffer to accommodate read-ahead limit */
                     //
                     // Android-changed: Use the same strategy as BufferedInputStream,
                     // i.e, double the size of the buffer on each fill. Do not directly
                     // size the buffer to the readAheadLimit.
                     //
                     // char ncb[] = new char[readAheadLimit];
                     int nlength = cb.length * 2;
                     if (nlength > readAheadLimit) {
                         nlength = readAheadLimit;
                     }
                     char ncb[] = new char[nlength];
                     System.arraycopy(cb, markedChar, ncb, 0, delta);
                     cb = ncb;
                     markedChar = 0;
                     dst = delta;
                 }
                 nextChar = nChars = delta;
             }
         }

         int n;
         do {
             n = in.read(cb, dst, cb.length - dst);
         } while (n == 0);
         if (n > 0) {
             nChars = dst + n;
             nextChar = dst;
         }
     }

     /**
      * Reads a single character.
      *
      * @return The character read, as an integer in the range
      *         0 to 65535 (<tt>0x00-0xffff</tt>), or -1 if the
      *         end of the stream has been reached
      * @exception  IOException  If an I/O error occurs
      */
     public int read() throws IOException {
         synchronized (lock) {
             ensureOpen();
             for (;;) {
                 if (nextChar >= nChars) {
                     fill();
                     if (nextChar >= nChars)
                         return -1;
                 }
                 if (skipLF) {
                     skipLF = false;
                     if (cb[nextChar] == '\n') {
                         nextChar++;
                         continue;
                     }
                 }
                 return cb[nextChar++];
             }
         }
     }

     /**
      * Reads characters into a portion of an array, reading from the underlying
      * stream if necessary.
      */
     private int read1(char[] cbuf, int off, int len) throws IOException {
         if (nextChar >= nChars) {
             /* If the requested length is at least as large as the buffer, and
                if there is no mark/reset activity, and if line feeds are not
                being skipped, do not bother to copy the characters into the
                local buffer.  In this way buffered streams will cascade
                harmlessly. */
             if (len >= cb.length && markedChar <= UNMARKED && !skipLF) {
                 return in.read(cbuf, off, len);
             }
             fill();
         }
         if (nextChar >= nChars) return -1;
         if (skipLF) {
             skipLF = false;
             if (cb[nextChar] == '\n') {
                 nextChar++;
                 if (nextChar >= nChars)
                     fill();
                 if (nextChar >= nChars)
                     return -1;
             }
         }
         int n = Math.min(len, nChars - nextChar);
         System.arraycopy(cb, nextChar, cbuf, off, n);
         nextChar += n;
         return n;
     }

     /**
      * Reads characters into a portion of an array.
      *
      * <p> This method implements the general contract of the corresponding
      * <code>{@link Reader#read(char[], int, int) read}</code> method of the
      * <code>{@link Reader}</code> class.  As an additional convenience, it
      * attempts to read as many characters as possible by repeatedly invoking
      * the <code>read</code> method of the underlying stream.  This iterated
      * <code>read</code> continues until one of the following conditions becomes
      * true: <ul>
      *
      *   <li> The specified number of characters have been read,
      *
      *   <li> The <code>read</code> method of the underlying stream returns
      *   <code>-1</code>, indicating end-of-file, or
      *
      *   <li> The <code>ready</code> method of the underlying stream
      *   returns <code>false</code>, indicating that further input requests
      *   would block.
      *
      * </ul> If the first <code>read</code> on the underlying stream returns
      * <code>-1</code> to indicate end-of-file then this method returns
      * <code>-1</code>.  Otherwise this method returns the number of characters
      * actually read.
      *
      * <p> Subclasses of this class are encouraged, but not required, to
      * attempt to read as many characters as possible in the same fashion.
      *
      * <p> Ordinarily this method takes characters from this stream's character
      * buffer, filling it from the underlying stream as necessary.  If,
      * however, the buffer is empty, the mark is not valid, and the requested
      * length is at least as large as the buffer, then this method will read
      * characters directly from the underlying stream into the given array.
      * Thus redundant <code>BufferedReader</code>s will not copy data
      * unnecessarily.
      *
      * @param      cbuf  Destination buffer
      * @param      off   Offset at which to start storing characters
      * @param      len   Maximum number of characters to read
      *
      * @return     The number of characters read, or -1 if the end of the
      *             stream has been reached
      *
      * @exception  IOException  If an I/O error occurs
      * @exception  IndexOutOfBoundsException {@inheritDoc}
      */
     public int read(char cbuf[], int off, int len) throws IOException {
         synchronized (lock) {
             ensureOpen();
             if ((off < 0) || (off > cbuf.length) || (len < 0) ||
                 ((off + len) > cbuf.length) || ((off + len) < 0)) {
                 throw new IndexOutOfBoundsException();
             } else if (len == 0) {
                 return 0;
             }

             int n = read1(cbuf, off, len);
             if (n <= 0) return n;
             while ((n < len) && in.ready()) {
                 int n1 = read1(cbuf, off + n, len - n);
                 if (n1 <= 0) break;
                 n += n1;
             }
             return n;
         }
     }

     /**
      * Reads a line of text.  A line is considered to be terminated by any one
      * of a line feed ('\n'), a carriage return ('\r'), a carriage return
      * followed immediately by a line feed, or by reaching the end-of-file
      * (EOF).
      *
      * @param      ignoreLF  If true, the next '\n' will be skipped
      *
      * @return     A String containing the contents of the line, not including
      *             any line-termination characters, or null if the end of the
      *             stream has been reached without reading any characters
      *
      * @see        java.io.LineNumberReader#readLine()
      *
      * @exception  IOException  If an I/O error occurs
      */
     String readLine(boolean ignoreLF) throws IOException {
         StringBuilder s = null;
         int startChar;

         synchronized (lock) {
             ensureOpen();
             boolean omitLF = ignoreLF || skipLF;

         bufferLoop:
             for (;;) {

                 if (nextChar >= nChars)
                     fill();
                 if (nextChar >= nChars) { /* EOF */
                     if (s != null && s.length() > 0)
                         return s.toString();
                     else
                         return null;
                 }
                 boolean eol = false;
                 char c = 0;
                 int i;

                 /* Skip a leftover '\n', if necessary */
                 if (omitLF && (cb[nextChar] == '\n'))
                     nextChar++;
                 skipLF = false;
                 omitLF = false;

             charLoop:
                 for (i = nextChar; i < nChars; i++) {
                     c = cb[i];
                     if ((c == '\n') || (c == '\r')) {
                         eol = true;
                         break charLoop;
                     }
                 }

                 startChar = nextChar;
                 nextChar = i;

                 if (eol) {
                     String str;
                     if (s == null) {
                         str = new String(cb, startChar, i - startChar);
                     } else {
                         s.append(cb, startChar, i - startChar);
                         str = s.toString();
                     }
                     nextChar++;
                     if (c == '\r') {
                         skipLF = true;
                     }
                     return str;
                 }

                 if (s == null)
                     s = new StringBuilder(defaultExpectedLineLength);
                 s.append(cb, startChar, i - startChar);
             }
         }
     }

     /**
      * Reads a line of text.  A line is considered to be terminated by any one
      * of a line feed ('\n'), a carriage return ('\r'), a carriage return
      * followed immediately by a line feed, or by reaching the end-of-file
      * (EOF).
      *
      * @return     A String containing the contents of the line, not including
      *             any line-termination characters, or null if the end of the
      *             stream has been reached without reading any characters
      *
      * @exception  IOException  If an I/O error occurs
      *
      * @see java.nio.file.Files#readAllLines
      */
     public String readLine() throws IOException {
         return readLine(false);
     }

     /**
      * Skips characters.
      *
      * @param  n  The number of characters to skip
      *
      * @return    The number of characters actually skipped
      *
      * @exception  IllegalArgumentException  If <code>n</code> is negative.
      * @exception  IOException  If an I/O error occurs
      */
     public long skip(long n) throws IOException {
         if (n < 0L) {
             throw new IllegalArgumentException("skip value is negative");
         }
         synchronized (lock) {
             ensureOpen();
             long r = n;
             while (r > 0) {
                 if (nextChar >= nChars)
                     fill();
                 if (nextChar >= nChars) /* EOF */
                     break;
                 if (skipLF) {
                     skipLF = false;
                     if (cb[nextChar] == '\n') {
                         nextChar++;
                     }
                 }
                 long d = nChars - nextChar;
                 if (r <= d) {
                     nextChar += r;
                     r = 0;
                     break;
                 }
                 else {
                     r -= d;
                     nextChar = nChars;
                 }
             }
             return n - r;
         }
     }

     /**
      * Tells whether this stream is ready to be read.  A buffered character
      * stream is ready if the buffer is not empty, or if the underlying
      * character stream is ready.
      *
      * @exception  IOException  If an I/O error occurs
      */
     public boolean ready() throws IOException {
         synchronized (lock) {
             ensureOpen();

             /*
              * If newline needs to be skipped and the next char to be read
              * is a newline character, then just skip it right away.
              */
             if (skipLF) {
                 /* Note that in.ready() will return true if and only if the next
                  * read on the stream will not block.
                  */
                 if (nextChar >= nChars && in.ready()) {
                     fill();
                 }
                 if (nextChar < nChars) {
                     if (cb[nextChar] == '\n')
                         nextChar++;
                     skipLF = false;
                 }
             }
             return (nextChar < nChars) || in.ready();
         }
     }

     /**
      * Tells whether this stream supports the mark() operation, which it does.
      */
     public boolean markSupported() {
         return true;
     }

     /**
      * Marks the present position in the stream.  Subsequent calls to reset()
      * will attempt to reposition the stream to this point.
      *
      * @param readAheadLimit   Limit on the number of characters that may be
      *                         read while still preserving the mark. An attempt
      *                         to reset the stream after reading characters
      *                         up to this limit or beyond may fail.
      *                         A limit value larger than the size of the input
      *                         buffer will cause a new buffer to be allocated
      *                         whose size is no smaller than limit.
      *                         Therefore large values should be used with care.
      *
      * @exception  IllegalArgumentException  If {@code readAheadLimit < 0}
      * @exception  IOException  If an I/O error occurs
      */
     public void mark(int readAheadLimit) throws IOException {
         if (readAheadLimit < 0) {
             throw new IllegalArgumentException("Read-ahead limit < 0");
         }
         synchronized (lock) {
             ensureOpen();
             this.readAheadLimit = readAheadLimit;
             markedChar = nextChar;
             markedSkipLF = skipLF;
         }
     }

     /**
      * Resets the stream to the most recent mark.
      *
      * @exception  IOException  If the stream has never been marked,
      *                          or if the mark has been invalidated
      */
     public void reset() throws IOException {
         synchronized (lock) {
             ensureOpen();
             if (markedChar < 0)
                 throw new IOException((markedChar == INVALIDATED)
                                       ? "Mark invalid"
                                       : "Stream not marked");
             nextChar = markedChar;
             skipLF = markedSkipLF;
         }
     }

     public void close() throws IOException {
         synchronized (lock) {
             if (in == null)
                 return;
             try {
                 in.close();
             } finally {
                 in = null;
                 cb = null;
             }
         }
     }

     /**
      * Returns a {@code Stream}, the elements of which are lines read from
      * this {@code BufferedReader}.  The {@link Stream} is lazily populated,
      * i.e., read only occurs during the
      * <a href="../util/stream/package-summary.html#StreamOps">terminal
      * stream operation</a>.
      *
      * <p> The reader must not be operated on during the execution of the
      * terminal stream operation. Otherwise, the result of the terminal stream
      * operation is undefined.
      *
      * <p> After execution of the terminal stream operation there are no
      * guarantees that the reader will be at a specific position from which to
      * read the next character or line.
      *
      * <p> If an {@link IOException} is thrown when accessing the underlying
      * {@code BufferedReader}, it is wrapped in an {@link
      * UncheckedIOException} which will be thrown from the {@code Stream}
      * method that caused the read to take place. This method will return a
      * Stream if invoked on a BufferedReader that is closed. Any operation on
      * that stream that requires reading from the BufferedReader after it is
      * closed, will cause an UncheckedIOException to be thrown.
      *
      * @return a {@code Stream<String>} providing the lines of text
      *         described by this {@code BufferedReader}
      *
      * @since 1.8
      */
     public Stream<String> lines() {
         Iterator<String> iter = new Iterator<>() {
             String nextLine = null;

             @Override
             public boolean hasNext() {
                 if (nextLine != null) {
                     return true;
                 } else {
                     try {
                         nextLine = readLine();
                         return (nextLine != null);
                     } catch (IOException e) {
                         throw new UncheckedIOException(e);
                     }
                 }
             }

             @Override
             public String next() {
                 if (nextLine != null || hasNext()) {
                     String line = nextLine;
                     nextLine = null;
                     return line;
                 } else {
                     throw new NoSuchElementException();
                 }
             }
         };
         return StreamSupport.stream(Spliterators.spliteratorUnknownSize(
                 iter, Spliterator.ORDERED | Spliterator.NONNULL), false);
     }
 }
	/*
	* Copyright (C) 2014 The Android Open Source Project
	* Copyright (c) 1996, 2017, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package java.io;


	import java.util.Iterator;
	import java.util.NoSuchElementException;
	import java.util.Spliterator;
	import java.util.Spliterators;
	import java.util.stream.Stream;
	import java.util.stream.StreamSupport;

	/**
	* Reads text from a character-input stream, buffering characters so as to
	* provide for the efficient reading of characters, arrays, and lines.
	*
	* <p> The buffer size may be specified, or the default size may be used. The
	* default is large enough for most purposes.
	*
	* <p> In general, each read request made of a Reader causes a corresponding
	* read request to be made of the underlying character or byte stream. It is
	* therefore advisable to wrap a BufferedReader around any Reader whose read()
	* operations may be costly, such as FileReaders and InputStreamReaders. For
	* example,
	*
	* <pre>
	* BufferedReader in
	* = new BufferedReader(new FileReader("foo.in"));
	* </pre>
	*
	* will buffer the input from the specified file. Without buffering, each
	* invocation of read() or readLine() could cause bytes to be read from the
	* file, converted into characters, and then returned, which can be very
	* inefficient.
	*
	* <p> Programs that use DataInputStreams for textual input can be localized by
	* replacing each DataInputStream with an appropriate BufferedReader.
	*
	* @see FileReader
	* @see InputStreamReader
	* @see java.nio.file.Files#newBufferedReader
	*
	* @author Mark Reinhold
	* @since 1.1
	*/

	public class BufferedReader extends Reader {

	private Reader in;

	private char cb[];
	private int nChars, nextChar;

	private static final int INVALIDATED = -2;
	private static final int UNMARKED = -1;
	private int markedChar = UNMARKED;
	private int readAheadLimit = 0; /* Valid only when markedChar > 0 */

	/** If the next character is a line feed, skip it */
	private boolean skipLF = false;

	/** The skipLF flag when the mark was set */
	private boolean markedSkipLF = false;

	private static int defaultCharBufferSize = 8192;
	private static int defaultExpectedLineLength = 80;

	/**
	* Creates a buffering character-input stream that uses an input buffer of
	* the specified size.
	*
	* @param in A Reader
	* @param sz Input-buffer size
	*
	* @exception IllegalArgumentException If {@code sz <= 0}
	*/
	public BufferedReader(Reader in, int sz) {
	super(in);
	if (sz <= 0)
	throw new IllegalArgumentException("Buffer size <= 0");
	this.in = in;
	cb = new char[sz];
	nextChar = nChars = 0;
	}

	/**
	* Creates a buffering character-input stream that uses a default-sized
	* input buffer.
	*
	* @param in A Reader
	*/
	public BufferedReader(Reader in) {
	this(in, defaultCharBufferSize);
	}

	/** Checks to make sure that the stream has not been closed */
	private void ensureOpen() throws IOException {
	if (in == null)
	throw new IOException("Stream closed");
	}

	/**
	* Fills the input buffer, taking the mark into account if it is valid.
	*/
	private void fill() throws IOException {
	int dst;
	if (markedChar <= UNMARKED) {
	/* No mark */
	dst = 0;
	} else {
	/* Marked */
	int delta = nextChar - markedChar;
	if (delta >= readAheadLimit) {
	/* Gone past read-ahead limit: Invalidate mark */
	markedChar = INVALIDATED;
	readAheadLimit = 0;
	dst = 0;
	} else {
	if (readAheadLimit <= cb.length) {
	/* Shuffle in the current buffer */
	System.arraycopy(cb, markedChar, cb, 0, delta);
	markedChar = 0;
	dst = delta;
	} else {
	/* Reallocate buffer to accommodate read-ahead limit */
	//
	// Android-changed: Use the same strategy as BufferedInputStream,
	// i.e, double the size of the buffer on each fill. Do not directly
	// size the buffer to the readAheadLimit.
	//
	// char ncb[] = new char[readAheadLimit];
	int nlength = cb.length * 2;
	if (nlength > readAheadLimit) {
	nlength = readAheadLimit;
	}
	char ncb[] = new char[nlength];
	System.arraycopy(cb, markedChar, ncb, 0, delta);
	cb = ncb;
	markedChar = 0;
	dst = delta;
	}
	nextChar = nChars = delta;
	}
	}

	int n;
	do {
	n = in.read(cb, dst, cb.length - dst);
	} while (n == 0);
	if (n > 0) {
	nChars = dst + n;
	nextChar = dst;
	}
	}

	/**
	* Reads a single character.
	*
	* @return The character read, as an integer in the range
	* 0 to 65535 (<tt>0x00-0xffff</tt>), or -1 if the
	* end of the stream has been reached
	* @exception IOException If an I/O error occurs
	*/
	public int read() throws IOException {
	synchronized (lock) {
	ensureOpen();
	for (;;) {
	if (nextChar >= nChars) {
	fill();
	if (nextChar >= nChars)
	return -1;
	}
	if (skipLF) {
	skipLF = false;
	if (cb[nextChar] == '\n') {
	nextChar++;
	continue;
	}
	}
	return cb[nextChar++];
	}
	}
	}

	/**
	* Reads characters into a portion of an array, reading from the underlying
	* stream if necessary.
	*/
	private int read1(char[] cbuf, int off, int len) throws IOException {
	if (nextChar >= nChars) {
	/* If the requested length is at least as large as the buffer, and
	if there is no mark/reset activity, and if line feeds are not
	being skipped, do not bother to copy the characters into the
	local buffer. In this way buffered streams will cascade
	harmlessly. */
	if (len >= cb.length && markedChar <= UNMARKED && !skipLF) {
	return in.read(cbuf, off, len);
	}
	fill();
	}
	if (nextChar >= nChars) return -1;
	if (skipLF) {
	skipLF = false;
	if (cb[nextChar] == '\n') {
	nextChar++;
	if (nextChar >= nChars)
	fill();
	if (nextChar >= nChars)
	return -1;
	}
	}
	int n = Math.min(len, nChars - nextChar);
	System.arraycopy(cb, nextChar, cbuf, off, n);
	nextChar += n;
	return n;
	}

	/**
	* Reads characters into a portion of an array.
	*
	* <p> This method implements the general contract of the corresponding
	* <code>{@link Reader#read(char[], int, int) read}</code> method of the
	* <code>{@link Reader}</code> class. As an additional convenience, it
	* attempts to read as many characters as possible by repeatedly invoking
	* the <code>read</code> method of the underlying stream. This iterated
	* <code>read</code> continues until one of the following conditions becomes
	* true: <ul>
	*
	* <li> The specified number of characters have been read,
	*
	* <li> The <code>read</code> method of the underlying stream returns
	* <code>-1</code>, indicating end-of-file, or
	*
	* <li> The <code>ready</code> method of the underlying stream
	* returns <code>false</code>, indicating that further input requests
	* would block.
	*
	* </ul> If the first <code>read</code> on the underlying stream returns
	* <code>-1</code> to indicate end-of-file then this method returns
	* <code>-1</code>. Otherwise this method returns the number of characters
	* actually read.
	*
	* <p> Subclasses of this class are encouraged, but not required, to
	* attempt to read as many characters as possible in the same fashion.
	*
	* <p> Ordinarily this method takes characters from this stream's character
	* buffer, filling it from the underlying stream as necessary. If,
	* however, the buffer is empty, the mark is not valid, and the requested
	* length is at least as large as the buffer, then this method will read
	* characters directly from the underlying stream into the given array.
	* Thus redundant <code>BufferedReader</code>s will not copy data
	* unnecessarily.
	*
	* @param cbuf Destination buffer
	* @param off Offset at which to start storing characters
	* @param len Maximum number of characters to read
	*
	* @return The number of characters read, or -1 if the end of the
	* stream has been reached
	*
	* @exception IOException If an I/O error occurs
	* @exception IndexOutOfBoundsException {@inheritDoc}
	*/
	public int read(char cbuf[], int off, int len) throws IOException {
	synchronized (lock) {
	ensureOpen();
	if ((off < 0) \|\| (off > cbuf.length) \|\| (len < 0) \|\|
	((off + len) > cbuf.length) \|\| ((off + len) < 0)) {
	throw new IndexOutOfBoundsException();
	} else if (len == 0) {
	return 0;
	}

	int n = read1(cbuf, off, len);
	if (n <= 0) return n;
	while ((n < len) && in.ready()) {
	int n1 = read1(cbuf, off + n, len - n);
	if (n1 <= 0) break;
	n += n1;
	}
	return n;
	}
	}

	/**
	* Reads a line of text. A line is considered to be terminated by any one
	* of a line feed ('\n'), a carriage return ('\r'), a carriage return
	* followed immediately by a line feed, or by reaching the end-of-file
	* (EOF).
	*
	* @param ignoreLF If true, the next '\n' will be skipped
	*
	* @return A String containing the contents of the line, not including
	* any line-termination characters, or null if the end of the
	* stream has been reached without reading any characters
	*
	* @see java.io.LineNumberReader#readLine()
	*
	* @exception IOException If an I/O error occurs
	*/
	String readLine(boolean ignoreLF) throws IOException {
	StringBuilder s = null;
	int startChar;

	synchronized (lock) {
	ensureOpen();
	boolean omitLF = ignoreLF \|\| skipLF;

	bufferLoop:
	for (;;) {

	if (nextChar >= nChars)
	fill();
	if (nextChar >= nChars) { /* EOF */
	if (s != null && s.length() > 0)
	return s.toString();
	else
	return null;
	}
	boolean eol = false;
	char c = 0;
	int i;

	/* Skip a leftover '\n', if necessary */
	if (omitLF && (cb[nextChar] == '\n'))
	nextChar++;
	skipLF = false;
	omitLF = false;

	charLoop:
	for (i = nextChar; i < nChars; i++) {
	c = cb[i];
	if ((c == '\n') \|\| (c == '\r')) {
	eol = true;
	break charLoop;
	}
	}

	startChar = nextChar;
	nextChar = i;

	if (eol) {
	String str;
	if (s == null) {
	str = new String(cb, startChar, i - startChar);
	} else {
	s.append(cb, startChar, i - startChar);
	str = s.toString();
	}
	nextChar++;
	if (c == '\r') {
	skipLF = true;
	}
	return str;
	}

	if (s == null)
	s = new StringBuilder(defaultExpectedLineLength);
	s.append(cb, startChar, i - startChar);
	}
	}
	}

	/**
	* Reads a line of text. A line is considered to be terminated by any one
	* of a line feed ('\n'), a carriage return ('\r'), a carriage return
	* followed immediately by a line feed, or by reaching the end-of-file
	* (EOF).
	*
	* @return A String containing the contents of the line, not including
	* any line-termination characters, or null if the end of the
	* stream has been reached without reading any characters
	*
	* @exception IOException If an I/O error occurs
	*
	* @see java.nio.file.Files#readAllLines
	*/
	public String readLine() throws IOException {
	return readLine(false);
	}

	/**
	* Skips characters.
	*
	* @param n The number of characters to skip
	*
	* @return The number of characters actually skipped
	*
	* @exception IllegalArgumentException If <code>n</code> is negative.
	* @exception IOException If an I/O error occurs
	*/
	public long skip(long n) throws IOException {
	if (n < 0L) {
	throw new IllegalArgumentException("skip value is negative");
	}
	synchronized (lock) {
	ensureOpen();
	long r = n;
	while (r > 0) {
	if (nextChar >= nChars)
	fill();
	if (nextChar >= nChars) /* EOF */
	break;
	if (skipLF) {
	skipLF = false;
	if (cb[nextChar] == '\n') {
	nextChar++;
	}
	}
	long d = nChars - nextChar;
	if (r <= d) {
	nextChar += r;
	r = 0;
	break;
	}
	else {
	r -= d;
	nextChar = nChars;
	}
	}
	return n - r;
	}
	}

	/**
	* Tells whether this stream is ready to be read. A buffered character
	* stream is ready if the buffer is not empty, or if the underlying
	* character stream is ready.
	*
	* @exception IOException If an I/O error occurs
	*/
	public boolean ready() throws IOException {
	synchronized (lock) {
	ensureOpen();

	/*
	* If newline needs to be skipped and the next char to be read
	* is a newline character, then just skip it right away.
	*/
	if (skipLF) {
	/* Note that in.ready() will return true if and only if the next
	* read on the stream will not block.
	*/
	if (nextChar >= nChars && in.ready()) {
	fill();
	}
	if (nextChar < nChars) {
	if (cb[nextChar] == '\n')
	nextChar++;
	skipLF = false;
	}
	}
	return (nextChar < nChars) \|\| in.ready();
	}
	}

	/**
	* Tells whether this stream supports the mark() operation, which it does.
	*/
	public boolean markSupported() {
	return true;
	}

	/**
	* Marks the present position in the stream. Subsequent calls to reset()
	* will attempt to reposition the stream to this point.
	*
	* @param readAheadLimit Limit on the number of characters that may be
	* read while still preserving the mark. An attempt
	* to reset the stream after reading characters
	* up to this limit or beyond may fail.
	* A limit value larger than the size of the input
	* buffer will cause a new buffer to be allocated
	* whose size is no smaller than limit.
	* Therefore large values should be used with care.
	*
	* @exception IllegalArgumentException If {@code readAheadLimit < 0}
	* @exception IOException If an I/O error occurs
	*/
	public void mark(int readAheadLimit) throws IOException {
	if (readAheadLimit < 0) {
	throw new IllegalArgumentException("Read-ahead limit < 0");
	}
	synchronized (lock) {
	ensureOpen();
	this.readAheadLimit = readAheadLimit;
	markedChar = nextChar;
	markedSkipLF = skipLF;
	}
	}

	/**
	* Resets the stream to the most recent mark.
	*
	* @exception IOException If the stream has never been marked,
	* or if the mark has been invalidated
	*/
	public void reset() throws IOException {
	synchronized (lock) {
	ensureOpen();
	if (markedChar < 0)
	throw new IOException((markedChar == INVALIDATED)
	? "Mark invalid"
	: "Stream not marked");
	nextChar = markedChar;
	skipLF = markedSkipLF;
	}
	}

	public void close() throws IOException {
	synchronized (lock) {
	if (in == null)
	return;
	try {
	in.close();
	} finally {
	in = null;
	cb = null;
	}
	}
	}

	/**
	* Returns a {@code Stream}, the elements of which are lines read from
	* this {@code BufferedReader}. The {@link Stream} is lazily populated,
	* i.e., read only occurs during the
	* <a href="../util/stream/package-summary.html#StreamOps">terminal
	* stream operation</a>.
	*
	* <p> The reader must not be operated on during the execution of the
	* terminal stream operation. Otherwise, the result of the terminal stream
	* operation is undefined.
	*
	* <p> After execution of the terminal stream operation there are no
	* guarantees that the reader will be at a specific position from which to
	* read the next character or line.
	*
	* <p> If an {@link IOException} is thrown when accessing the underlying
	* {@code BufferedReader}, it is wrapped in an {@link
	* UncheckedIOException} which will be thrown from the {@code Stream}
	* method that caused the read to take place. This method will return a
	* Stream if invoked on a BufferedReader that is closed. Any operation on
	* that stream that requires reading from the BufferedReader after it is
	* closed, will cause an UncheckedIOException to be thrown.
	*
	* @return a {@code Stream<String>} providing the lines of text
	* described by this {@code BufferedReader}
	*
	* @since 1.8
	*/
	public Stream<String> lines() {
	Iterator<String> iter = new Iterator<>() {
	String nextLine = null;

	@Override
	public boolean hasNext() {
	if (nextLine != null) {
	return true;
	} else {
	try {
	nextLine = readLine();
	return (nextLine != null);
	} catch (IOException e) {
	throw new UncheckedIOException(e);
	}
	}
	}

	@Override
	public String next() {
	if (nextLine != null \|\| hasNext()) {
	String line = nextLine;
	nextLine = null;
	return line;
	} else {
	throw new NoSuchElementException();
	}
	}
	};
	return StreamSupport.stream(Spliterators.spliteratorUnknownSize(
	iter, Spliterator.ORDERED \| Spliterator.NONNULL), false);
	}
	}