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Diffstat (limited to 'gcc-4.4.3/libjava/classpath/gnu/java/net/LineInputStream.java')
| -rw-r--r-- | gcc-4.4.3/libjava/classpath/gnu/java/net/LineInputStream.java | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/gcc-4.4.3/libjava/classpath/gnu/java/net/LineInputStream.java b/gcc-4.4.3/libjava/classpath/gnu/java/net/LineInputStream.java new file mode 100644 index 000000000..da307dbdd --- /dev/null +++ b/gcc-4.4.3/libjava/classpath/gnu/java/net/LineInputStream.java @@ -0,0 +1,224 @@ +/* LineInputStream.java -- + Copyright (C) 2002, 2003, 2004, 2005, 2006 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 gnu.java.net; + +import java.io.BufferedInputStream; +import java.io.ByteArrayOutputStream; +import java.io.IOException; +import java.io.InputStream; + +/** + * An input stream that can read lines of input. + * + * @author Chris Burdess (dog@gnu.org) + */ +public class LineInputStream + extends InputStream +{ + + /** + * The underlying input stream. + */ + protected InputStream in; + + /* + * Line buffer. + */ + private ByteArrayOutputStream buf; + + /* + * Encoding to use when translating bytes to characters. + */ + private String encoding; + + /* + * End-of-stream flag. + */ + private boolean eof; + + /** + * Whether we can use block reads. + */ + private final boolean blockReads; + + /** + * Constructor using the US-ASCII character encoding. + * @param in the underlying input stream + */ + public LineInputStream(InputStream in) + { + this(in, "US-ASCII"); + } + + /** + * Constructor. + * @param in the underlying input stream + * @param encoding the character encoding to use + */ + public LineInputStream(InputStream in, String encoding) + { + this.in = in; + buf = new ByteArrayOutputStream(); + this.encoding = encoding; + eof = false; + // If it is already buffered, additional buffering gains nothing. + blockReads = !(in instanceof BufferedInputStream) && in.markSupported(); + } + + public int read() + throws IOException + { + return in.read(); + } + + public int read(byte[] buf) + throws IOException + { + return in.read(buf); + } + + public int read(byte[] buf, int off, int len) + throws IOException + { + return in.read(buf, off, len); + } + + /** + * Read a line of input. + */ + public String readLine() + throws IOException + { + if (eof) + { + return null; + } + do + { + if (blockReads) + { + // Use mark and reset to read chunks of bytes + final int MAX_LENGTH = 1024; + int len, pos; + + len = in.available(); + if (len == 0 || len > MAX_LENGTH) + len = MAX_LENGTH; + byte[] b = new byte[len]; + in.mark(len); + // Read into buffer b + len = in.read(b, 0, len); + // Handle EOF + if (len == -1) + { + eof = true; + if (buf.size() == 0) + { + return null; + } + else + { + // We don't care about resetting buf + return buf.toString(encoding); + } + } + // Get index of LF in b + pos = indexOf(b, len, (byte) 0x0a); + if (pos != -1) + { + // Write pos bytes to buf + buf.write(b, 0, pos); + // Reset stream, and read pos + 1 bytes + in.reset(); + pos += 1; + while (pos > 0) + { + len = in.read(b, 0, pos); + pos = (len == -1) ? -1 : pos - len; + } + // Return line + String ret = buf.toString(encoding); + buf.reset(); + return ret; + } + else + { + // Append everything to buf and fall through to re-read. + buf.write(b, 0, len); + } + } + else + { + // We must use character reads in order not to read too much + // from the underlying stream. + int c = in.read(); + switch (c) + { + case -1: + eof = true; + if (buf.size() == 0) + { + return null; + } + // Fall through and return contents of buffer. + case 0x0a: // LF + String ret = buf.toString(encoding); + buf.reset(); + return ret; + default: + buf.write(c); + } + } + } + while (true); + } + + private int indexOf(byte[] b, int len, byte c) + { + for (int pos = 0; pos < len; pos++) + { + if (b[pos] == c) + { + return pos; + } + } + return -1; + } +} + |