|
|
|
|
@ -61,19 +61,32 @@ public class Compressor implements BLOB, Iterable<byte[]> {
|
|
|
|
|
|
|
|
|
|
/** Total size (in bytes) of uncompressed entries in buffer */
|
|
|
|
|
private long bufferlength;
|
|
|
|
|
|
|
|
|
|
/** Maximum {@link #bufferlength} value before compressing and flushing to the backend */
|
|
|
|
|
private final long maxbufferlength;
|
|
|
|
|
|
|
|
|
|
/** Maximum time (in milliseconds) to acquire a synchronization lock on get() and insert() */
|
|
|
|
|
private final long lockTimeout;
|
|
|
|
|
private long lockTimeout;
|
|
|
|
|
|
|
|
|
|
/** Synchronization lock */
|
|
|
|
|
private final ReentrantLock lock;
|
|
|
|
|
|
|
|
|
|
public Compressor(final BLOB backend, final long buffersize, final long lockTimeout) {
|
|
|
|
|
|
|
|
|
|
/** The compression level */
|
|
|
|
|
private int compressionLevel;
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* @param backend the backend storage
|
|
|
|
|
* @param buffersize the maximum total size (in bytes) of uncompressed in-memory entries before compressing and flushing to the backend
|
|
|
|
|
* @param lockTimeout maximum time to acquire a synchronization lock on get() and insert() operations
|
|
|
|
|
* @param compressionLevel the compression level : supported values ranging from 0 - no compression, to 9 - best compression
|
|
|
|
|
*/
|
|
|
|
|
public Compressor(final BLOB backend, final long buffersize, final long lockTimeout, final int compressionLevel) {
|
|
|
|
|
this.backend = backend;
|
|
|
|
|
this.maxbufferlength = buffersize;
|
|
|
|
|
this.lockTimeout = lockTimeout;
|
|
|
|
|
this.lock = new ReentrantLock();
|
|
|
|
|
/* Ensure a value within the range supported by the Deflater class */
|
|
|
|
|
this.compressionLevel = Math.max(Deflater.NO_COMPRESSION, Math.min(Deflater.BEST_COMPRESSION, compressionLevel));
|
|
|
|
|
initBuffer();
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
@ -125,21 +138,21 @@ public class Compressor implements BLOB, Iterable<byte[]> {
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
private static byte[] compress(final byte[] b) {
|
|
|
|
|
private static byte[] compress(final byte[] b, final int compressionLevel) {
|
|
|
|
|
final int l = b.length;
|
|
|
|
|
if (l < 100) return markWithPlainMagic(b);
|
|
|
|
|
final byte[] bb = compressAddMagic(b);
|
|
|
|
|
final byte[] bb = compressAddMagic(b, compressionLevel);
|
|
|
|
|
if (bb.length >= l) return markWithPlainMagic(b);
|
|
|
|
|
return bb;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
private static byte[] compressAddMagic(final byte[] b) {
|
|
|
|
|
private static byte[] compressAddMagic(final byte[] b, final int compressionLevel) {
|
|
|
|
|
// compress a byte array and add a leading magic for the compression
|
|
|
|
|
try {
|
|
|
|
|
//System.out.print("/(" + cdr + ")"); // DEBUG
|
|
|
|
|
final ByteArrayOutputStream baos = new ByteArrayOutputStream(b.length / 5);
|
|
|
|
|
baos.write(gzipMagic);
|
|
|
|
|
final OutputStream os = new GZIPOutputStream(baos, 65536){{def.setLevel(Deflater.BEST_COMPRESSION);}};
|
|
|
|
|
final OutputStream os = new GZIPOutputStream(baos, 65536){{def.setLevel(compressionLevel);}};
|
|
|
|
|
os.write(b);
|
|
|
|
|
os.close();
|
|
|
|
|
baos.close();
|
|
|
|
|
@ -213,7 +226,7 @@ public class Compressor implements BLOB, Iterable<byte[]> {
|
|
|
|
|
b = this.buffer.remove(key);
|
|
|
|
|
if (b != null) {
|
|
|
|
|
this.bufferlength = this.bufferlength - b.length;
|
|
|
|
|
this.backend.insert(key, compress(b));
|
|
|
|
|
this.backend.insert(key, compress(b, this.compressionLevel));
|
|
|
|
|
return b;
|
|
|
|
|
}
|
|
|
|
|
} finally {
|
|
|
|
|
@ -412,7 +425,7 @@ public class Compressor implements BLOB, Iterable<byte[]> {
|
|
|
|
|
final Map.Entry<byte[], byte[]> entry = this.buffer.entrySet().iterator().next();
|
|
|
|
|
this.buffer.remove(entry.getKey());
|
|
|
|
|
try {
|
|
|
|
|
this.backend.insert(entry.getKey(), compress(entry.getValue()));
|
|
|
|
|
this.backend.insert(entry.getKey(), compress(entry.getValue(), this.compressionLevel));
|
|
|
|
|
this.bufferlength -= entry.getValue().length;
|
|
|
|
|
return true;
|
|
|
|
|
} catch (final IOException e) {
|
|
|
|
|
@ -457,6 +470,23 @@ public class Compressor implements BLOB, Iterable<byte[]> {
|
|
|
|
|
insert(key, c);
|
|
|
|
|
return reduction;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* Set the new content compression level.
|
|
|
|
|
* @param compressionLevel the new compression level. Supported values between 0 (no compression) and 9 (best compression).
|
|
|
|
|
*/
|
|
|
|
|
public void setCompressionLevel(final int compressionLevel) {
|
|
|
|
|
/* Ensure a value within the range supported by the Deflater class */
|
|
|
|
|
this.compressionLevel = Math.max(Deflater.NO_COMPRESSION, Math.min(Deflater.BEST_COMPRESSION, compressionLevel));
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* Set the new synchronization lock timeout.
|
|
|
|
|
* @param lockTimeout the new synchronization lock timeout (in milliseconds).
|
|
|
|
|
*/
|
|
|
|
|
public void setLockTimeout(final long lockTimeout) {
|
|
|
|
|
this.lockTimeout = lockTimeout;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
}
|
|
|
|
|
|
luccioman
8 years ago