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Diffstat (limited to 'gcc-4.4.3/libjava/classpath/gnu/java/nio/ChannelWriter.java')
| -rw-r--r-- | gcc-4.4.3/libjava/classpath/gnu/java/nio/ChannelWriter.java | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/gcc-4.4.3/libjava/classpath/gnu/java/nio/ChannelWriter.java b/gcc-4.4.3/libjava/classpath/gnu/java/nio/ChannelWriter.java new file mode 100644 index 000000000..8e533ccbf --- /dev/null +++ b/gcc-4.4.3/libjava/classpath/gnu/java/nio/ChannelWriter.java @@ -0,0 +1,190 @@ +/* ChannelWriter.java -- nio / writer bridge + Copyright (C) 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.nio; + +import java.io.IOException; +import java.io.Writer; +import java.nio.ByteBuffer; +import java.nio.CharBuffer; +import java.nio.channels.WritableByteChannel; +import java.nio.charset.CharsetEncoder; +import java.nio.charset.CoderResult; + +/** + * A Writer implementation that works by wrapping an NIO channel. + */ +public class ChannelWriter + extends Writer +{ + private static final int DEFAULT_BUFFER_CAP = 8192; + + /** + * The output channel. + */ + private WritableByteChannel byteChannel; + + /** + * The encoder to use. + */ + private CharsetEncoder enc; + + /** + * The byte buffer. Translated characters are stored here on their way out. + */ + private ByteBuffer byteBuffer; + + /** + * The character buffer. Characters are stored here on their way into + * the encoder. + */ + private CharBuffer charBuffer; + + private void writeBuffer() throws IOException + { + byteBuffer.flip(); + byteChannel.write(byteBuffer); + } + + /** + * Create a new instance, given the output byte channel, the encoder + * to use, and the minimum buffer capacity. + */ + public ChannelWriter(WritableByteChannel ch, CharsetEncoder enc, + int minBufferCap) + { + this.byteChannel = ch; + this.enc = enc; + if (minBufferCap == -1) + minBufferCap = DEFAULT_BUFFER_CAP; + this.byteBuffer + = ByteBuffer.allocate((int) (minBufferCap * enc.maxBytesPerChar())); + this.charBuffer = CharBuffer.allocate(minBufferCap); + this.charBuffer.clear(); + } + + /* (non-Javadoc) + * @see java.io.Writer#flush() + */ + public void flush() throws IOException + { + // Presumably if we have characters in our buffer, it is + // due to an underflow. So we don't bother trying to flush + // that here. + } + + /* (non-Javadoc) + * @see java.io.Writer#close() + */ + public void close() throws IOException + { + synchronized (lock) + { + if (enc == null) + throw new IOException("writer already closed"); + + byteBuffer.clear(); + charBuffer.flip(); + CoderResult res = enc.encode(charBuffer, byteBuffer, true); + if (res.isError() || res.isMalformed() || res.isUnmappable()) + res.throwException(); + writeBuffer(); + + byteBuffer.clear(); + res = enc.flush(byteBuffer); + if (res.isError() || res.isMalformed() || res.isUnmappable()) + res.throwException(); + writeBuffer(); + enc = null; + } + } + + /* (non-Javadoc) + * @see java.io.Writer#write(char[], int, int) + */ + public void write(char[] buf, int offset, int len) throws IOException + { + synchronized (lock) + { + if (enc == null) + throw new IOException("writer already closed"); + int lastLen = -1; + while (len > 0) + { + // Copy data into our character buffer. + int allowed = Math.min(charBuffer.remaining(), len); + charBuffer.put(buf, offset, allowed); + // Update for the next pass through the loop. + offset += allowed; + len -= allowed; + charBuffer.flip(); + // If we didn't make any progress, we want to clean up + // and save our state for the next write(). + if (len == lastLen) + { + if (len <= charBuffer.remaining()) + { + charBuffer.put(buf, offset, len); + charBuffer.flip(); + } + else + { + CharBuffer ncb = CharBuffer.allocate(charBuffer.length() + + len); + ncb.put(charBuffer); + ncb.put(buf, offset, len); + charBuffer = ncb; + } + break; + } + lastLen = len; + + // Convert. + byteBuffer.clear(); + CoderResult res = enc.encode(charBuffer, byteBuffer, false); + // Compact here, as we want to leave the buffer in the + // right state for any future put()s. + charBuffer.compact(); + if (res.isError() || res.isMalformed() || res.isUnmappable()) + res.throwException(); + // Write the byte buffer to the output channel. + writeBuffer(); + } + } + } +} |