From 554fd8c5195424bdbcabf5de30fdc183aba391bd Mon Sep 17 00:00:00 2001 From: upstream source tree Date: Sun, 15 Mar 2015 20:14:05 -0400 Subject: obtained gcc-4.6.4.tar.bz2 from upstream website; verified gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream tarball. downloading a git-generated archive based on the 'upstream' tag should provide you with a source tree that is binary identical to the one extracted from the above tarball. if you have obtained the source via the command 'git clone', however, do note that line-endings of files in your working directory might differ from line-endings of the respective files in the upstream repository. --- libjava/classpath/java/io/BufferedReader.java | 575 ++++++++++++++++++++++++++ 1 file changed, 575 insertions(+) create mode 100644 libjava/classpath/java/io/BufferedReader.java (limited to 'libjava/classpath/java/io/BufferedReader.java') diff --git a/libjava/classpath/java/io/BufferedReader.java b/libjava/classpath/java/io/BufferedReader.java new file mode 100644 index 000000000..868fa3a94 --- /dev/null +++ b/libjava/classpath/java/io/BufferedReader.java @@ -0,0 +1,575 @@ +/* BufferedReader.java + Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 + Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath 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 for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package java.io; + +import gnu.java.lang.CPStringBuilder; + +/* Written using "Java Class Libraries", 2nd edition, plus online + * API docs for JDK 1.2 beta from http://www.javasoft.com. + * Status: Believed complete and correct. + */ + +/** + * This subclass of FilterReader buffers input from an + * underlying implementation to provide a possibly more efficient read + * mechanism. It maintains the buffer and buffer state in instance + * variables that are available to subclasses. The default buffer size + * of 8192 chars can be overridden by the creator of the stream. + *

+ * This class also implements mark/reset functionality. It is capable + * of remembering any number of input chars, to the limits of + * system memory or the size of Integer.MAX_VALUE + * + * @author Per Bothner (bothner@cygnus.com) + * @author Aaron M. Renn (arenn@urbanophile.com) + */ +public class BufferedReader extends Reader +{ + Reader in; + char[] buffer; + /* Index of current read position. Must be >= 0 and <= limit. */ + /* There is a special case where pos may be equal to limit+1; this + * is used as an indicator that a readLine was done with a '\r' was + * the very last char in the buffer. Since we don't want to read-ahead + * and potentially block, we set pos this way to indicate the situation + * and deal with it later. Doing it this way rather than having a + * separate boolean field to indicate the condition has the advantage + * that it is self-clearing on things like mark/reset. + */ + int pos; + /* Limit of valid data in buffer. Must be >= pos and <= buffer.length. */ + /* This can be < pos in the one special case described above. */ + int limit; + + /* The value -1 means there is no mark, or the mark has been invalidated. + Otherwise, markPos is the index in the buffer of the marked position. + Must be >= 0 and <= pos. + Note we do not explicitly store the read-limit. + The implicit read-limit is (buffer.length - markPos), which is + guaranteed to be >= the read-limit requested in the call to mark. */ + int markPos = -1; + + // The JCL book specifies the default buffer size as 8K characters. + // This is package-private because it is used by LineNumberReader. + static final int DEFAULT_BUFFER_SIZE = 8192; + + /** + * Create a new BufferedReader that will read from the + * specified subordinate stream with a default buffer size of 8192 chars. + * + * @param in The subordinate stream to read from + */ + public BufferedReader(Reader in) + { + this(in, DEFAULT_BUFFER_SIZE); + } + + /** + * Create a new BufferedReader that will read from the + * specified subordinate stream with a buffer size that is specified by the + * caller. + * + * @param in The subordinate stream to read from + * @param size The buffer size to use + * + * @exception IllegalArgumentException if size <= 0 + */ + public BufferedReader(Reader in, int size) + { + super(in.lock); + if (size <= 0) + throw new IllegalArgumentException("Illegal buffer size: " + size); + this.in = in; + buffer = new char[size]; + } + + /** + * This method closes the underlying stream and frees any associated + * resources. + * + * @exception IOException If an error occurs + */ + public void close() throws IOException + { + synchronized (lock) + { + if (in != null) + in.close(); + in = null; + buffer = null; + } + } + + /** + * Returns true to indicate that this class supports mark/reset + * functionality. + * + * @return true + */ + public boolean markSupported() + { + return true; + } + + /** + * Mark a position in the input to which the stream can be + * "reset" by calling the reset() method. The parameter + * readLimit is the number of chars that can be read from the + * stream after setting the mark before the mark becomes invalid. For + * example, if mark() is called with a read limit of 10, then + * when 11 chars of data are read from the stream before the + * reset() method is called, then the mark is invalid and the + * stream object instance is not required to remember the mark. + *

+ * Note that the number of chars that can be remembered by this method + * can be greater than the size of the internal read buffer. It is also + * not dependent on the subordinate stream supporting mark/reset + * functionality. + * + * @param readLimit The number of chars that can be read before the mark + * becomes invalid + * + * @exception IOException If an error occurs + * @exception IllegalArgumentException if readLimit is negative. + */ + public void mark(int readLimit) throws IOException + { + if (readLimit < 0) + throw new IllegalArgumentException("Read-ahead limit is negative"); + + synchronized (lock) + { + checkStatus(); + // In this method we need to be aware of the special case where + // pos + 1 == limit. This indicates that a '\r' was the last char + // in the buffer during a readLine. We'll want to maintain that + // condition after we shift things around and if a larger buffer is + // needed to track readLimit, we'll have to make it one element + // larger to ensure we don't invalidate the mark too early, if the + // char following the '\r' is NOT a '\n'. This is ok because, per + // the spec, we are not required to invalidate when passing readLimit. + // + // Note that if 'pos > limit', then doing 'limit -= pos' will cause + // limit to be negative. This is the only way limit will be < 0. + + if (pos + readLimit > limit) + { + char[] old_buffer = buffer; + int extraBuffSpace = 0; + if (pos > limit) + extraBuffSpace = 1; + if (readLimit + extraBuffSpace > limit) + buffer = new char[readLimit + extraBuffSpace]; + limit -= pos; + if (limit >= 0) + { + System.arraycopy(old_buffer, pos, buffer, 0, limit); + pos = 0; + } + } + + if (limit < 0) + { + // Maintain the relationship of 'pos > limit'. + pos = 1; + limit = markPos = 0; + } + else + markPos = pos; + // Now pos + readLimit <= buffer.length. thus if we need to read + // beyond buffer.length, then we are allowed to invalidate markPos. + } + } + + /** + * Reset the stream to the point where the mark() method + * was called. Any chars that were read after the mark point was set will + * be re-read during subsequent reads. + *

+ * This method will throw an IOException if the number of chars read from + * the stream since the call to mark() exceeds the mark limit + * passed when establishing the mark. + * + * @exception IOException If an error occurs; + */ + public void reset() throws IOException + { + synchronized (lock) + { + checkStatus(); + if (markPos < 0) + throw new IOException("mark never set or invalidated"); + + // Need to handle the extremely unlikely case where a readLine was + // done with a '\r' as the last char in the buffer; which was then + // immediately followed by a mark and a reset with NO intervening + // read of any sort. In that case, setting pos to markPos would + // lose that info and a subsequent read would thus not skip a '\n' + // (if one exists). The value of limit in this rare case is zero. + // We can assume that if limit is zero for other reasons, then + // pos is already set to zero and doesn't need to be readjusted. + if (limit > 0) + pos = markPos; + } + } + + /** + * This method determines whether or not a stream is ready to be read. If + * this method returns false then this stream could (but is + * not guaranteed to) block on the next read attempt. + * + * @return true if this stream is ready to be read, + * false otherwise + * + * @exception IOException If an error occurs + */ + public boolean ready() throws IOException + { + synchronized (lock) + { + checkStatus(); + return pos < limit || in.ready(); + } + } + + /** + * This method read chars from a stream and stores them into a caller + * supplied buffer. It starts storing the data at index + * offset into + * the buffer and attempts to read len chars. This method can + * return before reading the number of chars requested. The actual number + * of chars read is returned as an int. A -1 is returned to indicate the + * end of the stream. + *

+ * This method will block until some data can be read. + * + * @param buf The array into which the chars read should be stored + * @param offset The offset into the array to start storing chars + * @param count The requested number of chars to read + * + * @return The actual number of chars read, or -1 if end of stream. + * + * @exception IOException If an error occurs. + * @exception IndexOutOfBoundsException If offset and count are not + * valid regarding buf. + */ + public int read(char[] buf, int offset, int count) throws IOException + { + if (offset < 0 || offset + count > buf.length || count < 0) + throw new IndexOutOfBoundsException(); + + synchronized (lock) + { + checkStatus(); + // Once again, we need to handle the special case of a readLine + // that has a '\r' at the end of the buffer. In this case, we'll + // need to skip a '\n' if it is the next char to be read. + // This special case is indicated by 'pos > limit'. + boolean retAtEndOfBuffer = false; + + int avail = limit - pos; + if (count > avail) + { + if (avail > 0) + count = avail; + else // pos >= limit + { + if (limit == buffer.length) + markPos = -1; // read too far - invalidate the mark. + if (pos > limit) + { + // Set a boolean and make pos == limit to simplify things. + retAtEndOfBuffer = true; + --pos; + } + if (markPos < 0) + { + // Optimization: can read directly into buf. + if (count >= buffer.length && !retAtEndOfBuffer) + return in.read(buf, offset, count); + pos = limit = 0; + } + avail = in.read(buffer, limit, buffer.length - limit); + if (retAtEndOfBuffer && avail > 0 && buffer[limit] == '\n') + { + --avail; + limit++; + } + if (avail < count) + { + if (avail <= 0) + return avail; + count = avail; + } + limit += avail; + } + } + System.arraycopy(buffer, pos, buf, offset, count); + pos += count; + return count; + } + } + + /* Read more data into the buffer. Update pos and limit appropriately. + Assumes pos==limit initially. May invalidate the mark if read too much. + Return number of chars read (never 0), or -1 on eof. */ + private int fill() throws IOException + { + checkStatus(); + // Handle the special case of a readLine that has a '\r' at the end of + // the buffer. In this case, we'll need to skip a '\n' if it is the + // next char to be read. This special case is indicated by 'pos > limit'. + boolean retAtEndOfBuffer = false; + if (pos > limit) + { + retAtEndOfBuffer = true; + --pos; + } + + if (markPos >= 0 && limit == buffer.length) + markPos = -1; + if (markPos < 0) + pos = limit = 0; + int count = in.read(buffer, limit, buffer.length - limit); + if (count > 0) + limit += count; + + if (retAtEndOfBuffer && buffer[pos] == '\n') + { + --count; + // If the mark was set to the location of the \n, then we + // must change it to fully pretend that the \n does not + // exist. + if (markPos == pos) + ++markPos; + ++pos; + } + + return count; + } + + public int read() throws IOException + { + synchronized (lock) + { + checkStatus(); + if (pos >= limit && fill () <= 0) + return -1; + return buffer[pos++]; + } + } + + /* Return the end of the line starting at this.pos and ending at limit. + * The index returns is *before* any line terminators, or limit + * if no line terminators were found. + */ + private int lineEnd(int limit) + { + int i = pos; + for (; i < limit; i++) + { + char ch = buffer[i]; + if (ch == '\n' || ch == '\r') + break; + } + return i; + } + + /** + * This method reads a single line of text from the input stream, returning + * it as a String. A line is terminated by "\n", a "\r", or + * an "\r\n" sequence. The system dependent line separator is not used. + * The line termination characters are not returned in the resulting + * String. + * + * @return The line of text read, or null if end of stream. + * + * @exception IOException If an error occurs + */ + public String readLine() throws IOException + { + checkStatus(); + // Handle the special case where a previous readLine (with no intervening + // reads/skips) had a '\r' at the end of the buffer. + // In this case, we'll need to skip a '\n' if it's the next char to be read. + // This special case is indicated by 'pos > limit'. + if (pos > limit) + { + int ch = read(); + if (ch < 0) + return null; + if (ch != '\n') + --pos; + } + int i = lineEnd(limit); + if (i < limit) + { + String str = String.valueOf(buffer, pos, i - pos); + pos = i + 1; + // If the last char in the buffer is a '\r', we must remember + // to check if the next char to be read after the buffer is refilled + // is a '\n'. If so, skip it. To indicate this condition, we set pos + // to be limit + 1, which normally is never possible. + if (buffer[i] == '\r') + if (pos == limit || buffer[pos] == '\n') + pos++; + return str; + } + CPStringBuilder sbuf = new CPStringBuilder(200); + sbuf.append(buffer, pos, i - pos); + pos = i; + // We only want to return null when no characters were read before + // EOF. So we must keep track of this separately. Otherwise we + // would treat an empty `sbuf' as an EOF condition, which is wrong + // when there is just a newline. + boolean eof = false; + for (;;) + { + // readLine should block. So we must not return until a -1 is reached. + if (pos >= limit) + { + // here count == 0 isn't sufficient to give a failure. + int count = fill(); + if (count < 0) + { + eof = true; + break; + } + continue; + } + int ch = buffer[pos++]; + if (ch == '\n' || ch == '\r') + { + // Check here if a '\r' was the last char in the buffer; if so, + // mark it as in the comment above to indicate future reads + // should skip a newline that is the next char read after + // refilling the buffer. + if (ch == '\r') + if (pos == limit || buffer[pos] == '\n') + pos++; + break; + } + i = lineEnd(limit); + sbuf.append(buffer, pos - 1, i - (pos - 1)); + pos = i; + } + return (sbuf.length() == 0 && eof) ? null : sbuf.toString(); + } + + /** + * This method skips the specified number of chars in the stream. It + * returns the actual number of chars skipped, which may be less than the + * requested amount. + *

+ * This method first discards chars in the buffer, then calls the + * skip method on the underlying stream to skip the + * remaining chars. + * + * @param count The requested number of chars to skip + * + * @return The actual number of chars skipped. + * + * @exception IOException If an error occurs. + * @exception IllegalArgumentException If count is negative. + */ + public long skip(long count) throws IOException + { + synchronized (lock) + { + checkStatus(); + if (count < 0) + throw new IllegalArgumentException("skip value is negative"); + if (count == 0) + return 0; + // Yet again, we need to handle the special case of a readLine + // that has a '\r' at the end of the buffer. In this case, we need + // to ignore a '\n' if it is the next char to be read. + // This special case is indicated by 'pos > limit' (i.e. avail < 0). + // To simplify things, if we're dealing with the special case for + // readLine, just read the next char (since the fill method will + // skip the '\n' for us). By doing this, we'll have to back up pos. + // That's easier than trying to keep track of whether we've skipped + // one element or not. + if (pos > limit) + { + if (read() < 0) + return 0; + else + --pos; + } + + int avail = limit - pos; + + if (count < avail) + { + pos += count; + return count; + } + + pos = limit; + long todo = count - avail; + if (todo > buffer.length) + { + markPos = -1; + todo -= in.skip(todo); + } + else + { + while (todo > 0) + { + avail = fill(); + if (avail <= 0) + break; + if (avail > todo) + avail = (int) todo; + pos += avail; + todo -= avail; + } + } + return count - todo; + } + } + + private void checkStatus() throws IOException + { + if (in == null) + throw new IOException("Stream closed"); + } +} -- cgit v1.2.3