package net.rubyeye.xmemcached.transcoders;
import java.io.*;
import java.util.zip.DeflaterOutputStream;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
import java.util.zip.InflaterInputStream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Base class for any transcoders that may want to work with serialized or
* compressed data.
*/
public abstract class BaseSerializingTranscoder {
private static final class XmcObjectInputStream extends ObjectInputStream {
private XmcObjectInputStream(InputStream in) throws IOException {
super(in);
}
@Override
protected Class<?> resolveClass(ObjectStreamClass desc) throws IOException, ClassNotFoundException {
try {
//When class is not found,try to load it from context class loader.
return super.resolveClass(desc);
} catch (ClassNotFoundException e) {
return Thread.currentThread().getContextClassLoader().loadClass(desc.getName());
}
}
}
/**
* Default compression threshold value.
*/
public static final int DEFAULT_COMPRESSION_THRESHOLD = 16384;
public static final String DEFAULT_CHARSET = "UTF-8";
protected int compressionThreshold = DEFAULT_COMPRESSION_THRESHOLD;
protected String charset = DEFAULT_CHARSET;
protected CompressionMode compressMode = CompressionMode.GZIP;
protected static final Logger log = LoggerFactory
.getLogger(BaseSerializingTranscoder.class);
/**
* Set the compression threshold to the given number of bytes. This
* transcoder will attempt to compress any data being stored that's larger
* than this.
*
* @param to
* the number of bytes
*/
public void setCompressionThreshold(int to) {
this.compressionThreshold = to;
}
public CompressionMode getCompressMode() {
return compressMode;
}
public void setCompressionMode(CompressionMode compressMode) {
this.compressMode = compressMode;
}
/**
* Set the character set for string value transcoding (defaults to UTF-8).
*/
public void setCharset(String to) {
// Validate the character set.
try {
new String(new byte[97], to);
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
this.charset = to;
}
/**
* Get the bytes representing the given serialized object.
*/
protected byte[] serialize(Object o) {
if (o == null) {
throw new NullPointerException("Can't serialize null");
}
byte[] rv = null;
try {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
ObjectOutputStream os = new ObjectOutputStream(bos);
os.writeObject(o);
os.close();
bos.close();
rv = bos.toByteArray();
} catch (IOException e) {
throw new IllegalArgumentException("Non-serializable object", e);
}
return rv;
}
/**
* Get the object represented by the given serialized bytes.
*/
protected Object deserialize(byte[] in) {
Object rv = null;
ByteArrayInputStream bis = null;
ObjectInputStream is = null;
try {
if (in != null) {
bis = new ByteArrayInputStream(in);
is = new XmcObjectInputStream(bis);
rv = is.readObject();
}
} catch (IOException e) {
log.error("Caught IOException decoding " + in.length
+ " bytes of data", e);
} catch (ClassNotFoundException e) {
log.error("Caught CNFE decoding " + in.length + " bytes of data", e);
} finally {
if (is != null) {
try {
is.close();
} catch (IOException e) {
// ignore
}
}
if (bis != null) {
try {
bis.close();
} catch (IOException e) {
// ignore
}
}
}
return rv;
}
/**
* Compress the given array of bytes.
*/
public final byte[] compress(byte[] in) {
switch (this.compressMode) {
case GZIP:
return gzipCompress(in);
case ZIP:
return zipCompress(in);
default:
return gzipCompress(in);
}
}
private byte[] zipCompress(byte[] in) {
ByteArrayOutputStream baos = new ByteArrayOutputStream(in.length);
DeflaterOutputStream os = new DeflaterOutputStream(baos);
try {
os.write(in);
os.finish();
try {
os.close();
} catch (IOException e) {
log.error("Close DeflaterOutputStream error", e);
}
} catch (IOException e) {
throw new RuntimeException("IO exception compressing data", e);
} finally {
try {
baos.close();
} catch (IOException e) {
log.error("Close ByteArrayOutputStream error", e);
}
}
return baos.toByteArray();
}
private static byte[] gzipCompress(byte[] in) {
if (in == null) {
throw new NullPointerException("Can't compress null");
}
ByteArrayOutputStream bos = new ByteArrayOutputStream();
GZIPOutputStream gz = null;
try {
gz = new GZIPOutputStream(bos);
gz.write(in);
} catch (IOException e) {
throw new RuntimeException("IO exception compressing data", e);
} finally {
if (gz != null) {
try {
gz.close();
} catch (IOException e) {
log.error("Close GZIPOutputStream error", e);
}
}
if (bos != null) {
try {
bos.close();
} catch (IOException e) {
log.error("Close ByteArrayOutputStream error", e);
}
}
}
byte[] rv = bos.toByteArray();
// log.debug("Compressed %d bytes to %d", in.length, rv.length);
return rv;
}
static int COMPRESS_RATIO = 8;
/**
* Decompress the given array of bytes.
*
* @return null if the bytes cannot be decompressed
*/
protected byte[] decompress(byte[] in) {
switch (this.compressMode) {
case GZIP:
return gzipDecompress(in);
case ZIP:
return zipDecompress(in);
default:
return gzipDecompress(in);
}
}
private byte[] zipDecompress(byte[] in) {
int size = in.length * COMPRESS_RATIO;
ByteArrayInputStream bais = new ByteArrayInputStream(in);
InflaterInputStream is = new InflaterInputStream(bais);
ByteArrayOutputStream baos = new ByteArrayOutputStream(size);
try {
byte[] uncompressMessage = new byte[size];
while (true) {
int len = is.read(uncompressMessage);
if (len <= 0) {
break;
}
baos.write(uncompressMessage, 0, len);
}
baos.flush();
return baos.toByteArray();
} catch (IOException e) {
log.error("Failed to decompress data", e);
//baos = null;
} finally {
try {
is.close();
} catch (IOException e) {
log.error("failed to close InflaterInputStream");
}
try {
bais.close();
} catch (IOException e) {
log.error("failed to close ByteArrayInputStream");
}
try {
baos.close();
} catch (IOException e) {
log.error("failed to close ByteArrayOutputStream");
}
}
return baos == null ? null : baos.toByteArray();
}
private byte[] gzipDecompress(byte[] in) {
ByteArrayOutputStream bos = null;
if (in != null) {
ByteArrayInputStream bis = new ByteArrayInputStream(in);
bos = new ByteArrayOutputStream();
GZIPInputStream gis = null;
try {
gis = new GZIPInputStream(bis);
byte[] buf = new byte[64 * 1024];
int r = -1;
while ((r = gis.read(buf)) > 0) {
bos.write(buf, 0, r);
}
} catch (IOException e) {
log.error("Failed to decompress data", e);
bos = null;
} finally {
if (gis != null) {
try {
gis.close();
} catch (IOException e) {
log.error("Close GZIPInputStream error", e);
}
}
if (bis != null) {
try {
bis.close();
} catch (IOException e) {
log.error("Close ByteArrayInputStream error", e);
}
}
}
}
return bos == null ? null : bos.toByteArray();
}
/**
* Decode the string with the current character set.
*/
protected String decodeString(byte[] data) {
String rv = null;
try {
if (data != null) {
rv = new String(data, this.charset);
}
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
return rv;
}
/**
* Encode a string into the current character set.
*/
protected byte[] encodeString(String in) {
byte[] rv = null;
try {
rv = in.getBytes(this.charset);
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
return rv;
}
}