remove dependency to Guava

block-storage/src/main/java/org/lucares/pdb/map/PersistentMap.java

@@ -7,10 +7,10 @@ import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
-import java.util.function.Function;
 import java.util.Objects;
 import java.util.Stack;
 import java.util.UUID;
+import java.util.function.Function;
 
 import org.lucares.collections.LongList;
 import org.lucares.pdb.diskstorage.DiskBlock;
@@ -40,12 +40,12 @@ public class PersistentMap<K, V> implements AutoCloseable {
 		public byte[] encode(O object);
 
 		public O decode(byte[] bytes);
-		
+
 		public default Function<byte[], O> asDecoder() {
 			return bytes -> this.decode(bytes);
 		}
-		
-		public default Function<O,byte[]> asEncoder() {
+
+		public default Function<O, byte[]> asEncoder() {
 			return plain -> this.encode(plain);
 		}
 
@@ -63,9 +63,10 @@ public class PersistentMap<K, V> implements AutoCloseable {
 		public String decode(final byte[] bytes) {
 			return bytes == null ? null : new String(bytes, StandardCharsets.UTF_8);
 		}
-		
+
+		@Override
 		public byte[] getEmptyValue() {
-			return new byte[] {0};
+			return new byte[] { 0 };
 		}
 	}
 
@@ -80,9 +81,10 @@ public class PersistentMap<K, V> implements AutoCloseable {
 		public Long decode(final byte[] bytes) {
 			return bytes == null ? null : VariableByteEncoder.decodeFirstValue(bytes);
 		}
-		
+
+		@Override
 		public byte[] getEmptyValue() {
-			return new byte[] {0};
+			return new byte[] { 0 };
 		}
 	}
 
@@ -104,9 +106,10 @@ public class PersistentMap<K, V> implements AutoCloseable {
 
 			return new UUID(mostSignificantBits, leastSignificantBits);
 		}
-		
+
+		@Override
 		public byte[] getEmptyValue() {
-			return new byte[] {0};
+			return new byte[] { 0 };
 		}
 	}
 
@@ -121,12 +124,12 @@ public class PersistentMap<K, V> implements AutoCloseable {
 
 		@Override
 		public Empty decode(final byte[] bytes) {
-
-			Preconditions.checkEqual(bytes.length, 0, "");
+			Preconditions.checkTrue(bytes.length == 0, "");
 
 			return Empty.INSTANCE;
 		}
-		
+
+		@Override
 		public byte[] getEmptyValue() {
 			return new byte[] {};
 		}
@@ -152,7 +155,8 @@ public class PersistentMap<K, V> implements AutoCloseable {
 
 	private final LRUCache<K, V> valueCache = new LRUCache<>(1_000);
 
-	public PersistentMap(final Path path, final Path storageBasePath, final EncoderDecoder<K> keyEncoder, final EncoderDecoder<V> valueEncoder) {
+	public PersistentMap(final Path path, final Path storageBasePath, final EncoderDecoder<K> keyEncoder,
+			final EncoderDecoder<V> valueEncoder) {
 		this.diskStore = new DiskStorage(path, storageBasePath);
 		this.keyEncoder = keyEncoder;
 		this.valueEncoder = valueEncoder;