Add isValidCompressedBuffer for raw memory addresses

src/main/java/org/xerial/snappy/Snappy.java

@@ -320,6 +320,17 @@ public class Snappy
                 compressed.remaining());
     }
 
+    /**
+     * Returns true iff the contents of compressed buffer [offset,
+     * offset+length) can be uncompressed successfully. Does not return the
+     * uncompressed data. Takes time proportional to the input length, but is
+     * usually at least a factor of four faster than actual decompression.
+     */
+    public static boolean isValidCompressedBuffer(long inputAddr, long offset, long length) throws IOException {
+        return impl.isValidCompressedBuffer(inputAddr, offset, length);
+    }
+
+
     /**
      * Get the maximum byte size needed for compressing data of the given byte
      * size.