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Diffstat (limited to 'src/java/com/jogamp/common/util/CustomCompress.java')
-rw-r--r-- | src/java/com/jogamp/common/util/CustomCompress.java | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/src/java/com/jogamp/common/util/CustomCompress.java b/src/java/com/jogamp/common/util/CustomCompress.java new file mode 100644 index 0000000..6850873 --- /dev/null +++ b/src/java/com/jogamp/common/util/CustomCompress.java @@ -0,0 +1,121 @@ +/** + * Copyright 2015 JogAmp Community. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, are + * permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, this list of + * conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, this list + * of conditions and the following disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND + * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON + * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF + * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * The views and conclusions contained in the software and documentation are those of the + * authors and should not be interpreted as representing official policies, either expressed + * or implied, of JogAmp Community. + */ +package com.jogamp.common.util; + +import java.io.DataInputStream; +import java.io.DataOutputStream; +import java.io.IOException; +import java.io.InputStream; +import java.io.OutputStream; +import java.util.zip.DataFormatException; +import java.util.zip.Deflater; +import java.util.zip.Inflater; + +/** + * All in memory inflater / deflator for small chunks using streams + * <p> + * Stream format for deflated data: + * <ul> + * <li>4 bytes magic 0xDEF1A7E0 (Big Endian)</li> + * <li>4 bytes integer deflated-size (Big Endian)</li> + * <li>4 bytes integer inflated-size (Big Endian)</li> + * <li>deflated bytes</li> + * </ul> + * </p> + */ +public class CustomCompress { + public static final int MAGIC = 0xDEF1A7E0; + + public static byte[] inflateFromStream(final InputStream in) throws IOException { + final int inSize; + final int outSize; + { + final DataInputStream din = new DataInputStream(in); + final int _magic = din.readInt(); + if( _magic != MAGIC ) { + throw new IOException("wrong magic: "+Integer.toHexString(_magic)+", expected "+Integer.toHexString(MAGIC)); + } + inSize = din.readInt(); + outSize = din.readInt(); + } + if( 0 >= inSize ) { + throw new IOException("Invalid deflated-size "+inSize); + } + if( 0 >= outSize ) { + throw new IOException("Invalid inflated-size "+outSize); + } + final byte[] input = new byte[inSize]; + int numBytes = 0; + try { + while (true) { + final int remBytes = inSize - numBytes; + int count; + if ( 0 >= remBytes || (count = in.read(input, numBytes, remBytes)) == -1 ) { + break; + } + numBytes += count; + } + } finally { + in.close(); + } + if( inSize != numBytes ) { + throw new IOException("Got "+numBytes+" bytes != expected "+inSize); + } + final byte[] output = new byte[outSize]; + try { + final Inflater inflater = new Inflater(); + inflater.setInput(input, 0, inSize); + final int outSize2 = inflater.inflate(output, 0, outSize); + inflater.end(); + if( outSize != outSize2 ) { + throw new IOException("Got inflated "+outSize2+" bytes != expected "+outSize); + } + } catch(final DataFormatException dfe) { + throw new IOException(dfe); + } + return output; + } + + public static int deflateToStream(final byte[] input, final OutputStream out) throws IOException { + final byte[] output = new byte[input.length]; + final Deflater deflater = new Deflater(); + deflater.setInput(input, 0, input.length); + deflater.finish(); + final int outSize = deflater.deflate(output, 0, output.length); + deflater.end(); + { + final DataOutputStream dout = new DataOutputStream(out); + dout.writeInt(CustomCompress.MAGIC); + dout.writeInt(outSize); + dout.writeInt(input.length); + } + out.write(output, 0, outSize); + return outSize; + } + +} |