INTERNAL: Refactor transcoder compress logic.

src/main/java/net/spy/memcached/transcoders/BaseSerializingTranscoder.java

@@ -22,36 +22,35 @@
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 import java.io.UnsupportedEncodingException;
-import java.util.zip.GZIPInputStream;
-import java.util.zip.GZIPOutputStream;
 
 import net.spy.memcached.CachedData;
-import net.spy.memcached.compat.CloseUtil;
 import net.spy.memcached.compat.SpyObject;
 
 /**
  * Base class for any transcoders that may want to work with serialized or
  * compressed data.
  */
 public abstract class BaseSerializingTranscoder extends SpyObject {
-
-  /**
-   * Default compression threshold value.
-   */
-  public static final int DEFAULT_COMPRESSION_THRESHOLD = 16384;
-
   private static final String DEFAULT_CHARSET = "UTF-8";
-
-  protected int compressionThreshold = DEFAULT_COMPRESSION_THRESHOLD;
   protected String charset = DEFAULT_CHARSET;
-
+  protected final Compressor compressor;
   private final int maxSize;
 
   /**
    * Initialize a serializing transcoder with the given maximum data size.
    */
   public BaseSerializingTranscoder(int max) {
     super();
+    this.compressor = new GzipCompressor();
+    maxSize = max;
+  }
+
+  /**
+   * Initialize a serializing transcoder with the given maximum data size and compressor.
+   */
+  public BaseSerializingTranscoder(int max, Compressor compressor) {
+    super();
+    this.compressor = compressor;
     maxSize = max;
   }
 
@@ -67,7 +66,7 @@ public boolean asyncDecode(CachedData d) {
    * @param to the number of bytes
    */
   public void setCompressionThreshold(int to) {
-    compressionThreshold = to;
+    compressor.setCompressionThreshold(to);
   }
 
   /**
@@ -127,56 +126,6 @@ protected Object deserialize(byte[] in) {
     return rv;
   }
 
-  /**
-   * Compress the given array of bytes.
-   */
-  protected byte[] compress(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 {
-      CloseUtil.close(gz);
-      CloseUtil.close(bos);
-    }
-    byte[] rv = bos.toByteArray();
-    getLogger().debug("Compressed %d bytes to %d", in.length, rv.length);
-    return rv;
-  }
-
-  /**
-   * Decompress the given array of bytes.
-   *
-   * @return null if the bytes cannot be decompressed
-   */
-  protected byte[] decompress(byte[] in) {
-    ByteArrayOutputStream bos = null;
-    if (in != null) {
-      ByteArrayInputStream bis = new ByteArrayInputStream(in);
-      bos = new ByteArrayOutputStream();
-      GZIPInputStream gis;
-      try {
-        gis = new GZIPInputStream(bis);
-
-        byte[] buf = new byte[8192];
-        int r = -1;
-        while ((r = gis.read(buf)) > 0) {
-          bos.write(buf, 0, r);
-        }
-      } catch (IOException e) {
-        getLogger().warn("Failed to decompress data", e);
-        bos = null;
-      }
-    }
-    return bos == null ? null : bos.toByteArray();
-  }
-
   /**
    * Decode the string with the current character set.
    */

src/main/java/net/spy/memcached/transcoders/Compressor.java

@@ -0,0 +1,24 @@
+package net.spy.memcached.transcoders;
+
+public interface Compressor {
+  /**
+   * Default compression threshold value.
+   */
+  int DEFAULT_COMPRESSION_THRESHOLD = 16384;
+
+  /**
+   * Compress the given array of bytes.
+   */
+  public byte[] compress(byte[] in);
+
+  /**
+   * Decompress the given array of bytes.
+   *
+   * @return null if the bytes cannot be decompressed
+   */
+  public byte[] decompress(byte[] in);
+
+  public int getCompressionThreshold();
+
+  public void setCompressionThreshold(int to);
+}

src/main/java/net/spy/memcached/transcoders/GzipCompressor.java

@@ -0,0 +1,66 @@
+package net.spy.memcached.transcoders;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.util.zip.GZIPInputStream;
+import java.util.zip.GZIPOutputStream;
+
+import net.spy.memcached.compat.CloseUtil;
+import net.spy.memcached.compat.SpyObject;
+
+public class GzipCompressor extends SpyObject implements Compressor {
+  private int compressionThreshold = DEFAULT_COMPRESSION_THRESHOLD;
+
+  @Override
+  public byte[] compress(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 {
+      CloseUtil.close(gz);
+      CloseUtil.close(bos);
+    }
+    return bos.toByteArray();
+  }
+
+  @Override
+  public byte[] decompress(byte[] in) {
+    ByteArrayOutputStream bos = null;
+    if (in != null) {
+      ByteArrayInputStream bis = new ByteArrayInputStream(in);
+      bos = new ByteArrayOutputStream();
+      GZIPInputStream gis;
+      try {
+        gis = new GZIPInputStream(bis);
+        byte[] buf = new byte[8192];
+        int r = -1;
+        while ((r = gis.read(buf)) > 0) {
+          bos.write(buf, 0, r);
+        }
+      } catch (IOException e) {
+        getLogger().warn("Failed to decompress data", e);
+        bos = null;
+      }
+    }
+    return bos == null ? null : bos.toByteArray();
+  }
+
+  @Override
+  public int getCompressionThreshold() {
+    return compressionThreshold;
+  }
+
+  @Override
+  public void setCompressionThreshold(int compressionThreshold) {
+    this.compressionThreshold = compressionThreshold;
+  }
+
+}

src/main/java/net/spy/memcached/transcoders/SerializingTranscoder.java

@@ -59,6 +59,20 @@ public SerializingTranscoder(int max) {
     super(max);
   }
 
+  /**
+   * Get a serializing transcoder customized compressor.
+   */
+  public SerializingTranscoder(Compressor compressor) {
+    super(CachedData.MAX_SIZE, compressor);
+  }
+
+  /**
+   * Get a serializing transcoder that specifies the max data size and customized compressor.
+   */
+  public SerializingTranscoder(int max, Compressor compressor) {
+    super(max, compressor);
+  }
+
   @Override
   public boolean asyncDecode(CachedData d) {
     if ((d.getFlags() & COMPRESSED) != 0
@@ -72,7 +86,7 @@ public Object decode(CachedData d) {
     byte[] data = d.getData();
     Object rv = null;
     if ((d.getFlags() & COMPRESSED) != 0) {
-      data = decompress(d.getData());
+      data = compressor.decompress(d.getData());
     }
     int flags = d.getFlags() & SPECIAL_MASK;
     if ((d.getFlags() & SERIALIZED) != 0 && data != null) {
@@ -146,20 +160,21 @@ public CachedData encode(Object o) {
       flags |= SERIALIZED;
     }
     assert b != null;
-    if (b.length > compressionThreshold) {
-      byte[] compressed = compress(b);
+    if (b.length > compressor.getCompressionThreshold()) {
+      byte[] compressed = compressor.compress(b);
       if (compressed.length < b.length) {
-        getLogger().debug("Compressed %s from %d to %d",
-                o.getClass().getName(), b.length, compressed.length);
+        getLogger().debug("Compressed %s from %d to %d", o.getClass().getName(),
+                b.length, compressed.length);
         b = compressed;
         flags |= COMPRESSED;
-      } else {
-        getLogger().info(
-                "Compression increased the size of %s from %d to %d",
+      } else if (compressed.length > b.length) {
+        getLogger().info("Compression increased the size of %s from %d to %d",
                 o.getClass().getName(), b.length, compressed.length);
+      } else {
+        getLogger().info("Compression makes same length of %s : %d",
+                o.getClass().getName(), b.length);
       }
     }
     return new CachedData(flags, b, getMaxSize());
   }
-
 }

src/main/java/net/spy/memcached/transcoders/WhalinTranscoder.java

@@ -48,11 +48,15 @@ public WhalinTranscoder() {
     super(CachedData.MAX_SIZE);
   }
 
+  public WhalinTranscoder(Compressor compressor) {
+    super(CachedData.MAX_SIZE, compressor);
+  }
+
   public Object decode(CachedData d) {
     byte[] data = d.getData();
     Object rv = null;
     if ((d.getFlags() & COMPRESSED) != 0) {
-      data = decompress(d.getData());
+      data = compressor.decompress(d.getData());
     }
     if ((d.getFlags() & SERIALIZED) != 0) {
       rv = deserialize(data);
@@ -152,17 +156,19 @@ public CachedData encode(Object o) {
       flags |= SERIALIZED;
     }
     assert b != null;
-    if (b.length > compressionThreshold) {
-      byte[] compressed = compress(b);
+    if (b.length > compressor.getCompressionThreshold()) {
+      byte[] compressed = compressor.compress(b);
       if (compressed.length < b.length) {
-        getLogger().debug("Compressed %s from %d to %d",
-                o.getClass().getName(), b.length, compressed.length);
+        getLogger().debug("Compressed %s from %d to %d", o.getClass().getName(),
+                b.length, compressed.length);
         b = compressed;
         flags |= COMPRESSED;
-      } else {
-        getLogger().info(
-                "Compression increased the size of %s from %d to %d",
+      } else if (compressed.length > b.length) {
+        getLogger().info("Compression increased the size of %s from %d to %d",
                 o.getClass().getName(), b.length, compressed.length);
+      } else {
+        getLogger().info("Compression makes same length of %s : %d",
+                o.getClass().getName(), b.length);
       }
     }
     return new CachedData(flags, b, getMaxSize());

src/main/java/net/spy/memcached/transcoders/WhalinV1Transcoder.java

@@ -34,6 +34,10 @@ public WhalinV1Transcoder() {
     super(CachedData.MAX_SIZE);
   }
 
+  public WhalinV1Transcoder(Compressor compressor) {
+    super(CachedData.MAX_SIZE, compressor);
+  }
+
   public CachedData encode(Object o) {
     byte[] b = null;
     int flags = 0;
@@ -66,17 +70,19 @@ public CachedData encode(Object o) {
       flags |= SERIALIZED;
     }
     assert b != null;
-    if (b.length > compressionThreshold) {
-      byte[] compressed = compress(b);
+    if (b.length > compressor.getCompressionThreshold()) {
+      byte[] compressed = compressor.compress(b);
       if (compressed.length < b.length) {
-        getLogger().info("Compressed %s from %d to %d",
-                o.getClass().getName(), b.length, compressed.length);
+        getLogger().debug("Compressed %s from %d to %d", o.getClass().getName(),
+                b.length, compressed.length);
         b = compressed;
         flags |= COMPRESSED;
-      } else {
-        getLogger().info(
-                "Compression increased the size of %s from %d to %d",
+      } else if (compressed.length > b.length) {
+        getLogger().info("Compression increased the size of %s from %d to %d",
                 o.getClass().getName(), b.length, compressed.length);
+      } else {
+        getLogger().info("Compression makes same length of %s : %d",
+                o.getClass().getName(), b.length);
       }
     }
     return new CachedData(flags, b, getMaxSize());
@@ -86,7 +92,7 @@ public Object decode(CachedData d) {
     byte[] data = d.getData();
     Object rv = null;
     if ((d.getFlags() & COMPRESSED) != 0) {
-      data = decompress(d.getData());
+      data = compressor.decompress(d.getData());
     }
     if ((d.getFlags() & SERIALIZED) != 0) {
       rv = deserialize(data);

src/test/java/net/spy/memcached/transcoders/BaseSerializingTranscoderTest.java

@@ -33,7 +33,7 @@ public void testInvalidCharacterSet() {
 
   public void testCompressNull() {
     try {
-      ex.compress(null);
+      ex.compressor.compress(null);
       fail("Expected an assertion error");
     } catch (NullPointerException e) {
       // pass
@@ -67,7 +67,7 @@ public void testSerializeNull() {
   }
 
   public void testDecompressNull() {
-    assertNull(ex.decompress(null));
+    assertNull(ex.compressor.decompress(null));
   }
 
   public void testUndeserializable() throws Exception {
@@ -117,21 +117,11 @@ public void overrideCharsetSet(String to) {
       charset = to;
     }
 
-    @Override
-    public byte[] compress(byte[] in) {
-      return super.compress(in);
-    }
-
     @Override
     public String decodeString(byte[] data) {
       return super.decodeString(data);
     }
 
-    @Override
-    public byte[] decompress(byte[] in) {
-      return super.decompress(in);
-    }
-
     @Override
     public Object deserialize(byte[] in) {
       return super.deserialize(in);