Abdullah/mapdb transactions and blocks

src/main/java/model/crypto/Signature.java

@@ -1,17 +1,18 @@
 package model.crypto;
 
+import java.io.Serializable;
+
 import model.Entity;
 import model.lightchain.Identifier;
 
 /**
  * Represents abstract data type for the cryptographic digital signature used in LightChain.
  */
-public abstract class Signature extends Entity {
+public abstract class Signature extends Entity implements Serializable {
   /**
    * The signature value in bytes.
    */
   private final byte[] bytes;
-
   /**
    * Identifier of node that signed transaction.
    */

src/main/java/model/crypto/ecdsa/EcdsaSignature.java

@@ -1,13 +1,15 @@
 package model.crypto.ecdsa;
 
+import java.io.Serializable;
+
 import model.codec.EntityType;
 import model.crypto.Signature;
 import model.lightchain.Identifier;
 
 /**
  * ECDSA signature implementation with signer ID.
  */
-public class EcdsaSignature extends Signature {
+public class EcdsaSignature extends Signature implements Serializable {
   public static final String ELLIPTIC_CURVE = "EC";
   public static final String SIGN_ALG_SHA_3_256_WITH_ECDSA = "SHA3-256withECDSA";
 

src/main/java/model/lightchain/Block.java

@@ -1,12 +1,14 @@
 package model.lightchain;
 
+import java.io.Serializable;
+
 import model.codec.EntityType;
 import model.crypto.Signature;
 
 /**
  * Represents a LightChain Block that encapsulates set of ValidatedTransaction(s).
  */
-public class Block extends model.Entity {
+public class Block extends model.Entity implements Serializable {
   /**
    * Reference to the hash value of another block as its parent.
    */
@@ -72,6 +74,24 @@ public Block(Identifier previousBlockId,
     this.height = height;
   }
 
+  @Override
+  public int hashCode() {
+    return this.id().hashCode();
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (!(o instanceof Block))  {
+      return false;
+    }
+    Block that = (Block) o;
+
+    return this.id().equals(that.id());
+  }
+
   /**
    * Type of this entity.
    *

src/main/java/model/lightchain/Identifiers.java

@@ -1,11 +1,12 @@
 package model.lightchain;
 
+import java.io.Serializable;
 import java.util.ArrayList;
 
 /**
  * Represents an aggregated type for identifiers.
  */
-public class Identifiers {
+public class Identifiers implements Serializable {
   private final ArrayList<Identifier> identifiers;
 
   public Identifiers() {

src/main/java/model/lightchain/Transaction.java

@@ -1,12 +1,14 @@
 package model.lightchain;
 
+import java.io.Serializable;
+
 import model.codec.EntityType;
 import model.crypto.Signature;
 
 /**
  * Represents a LightChain transaction in form of a token transfer between a sender and receiver.
  */
-public class Transaction extends model.Entity {
+public class Transaction extends model.Entity implements Serializable {
   /**
    * The identifier of a finalized block that this transaction refers to its snapshot.
    */
@@ -51,6 +53,35 @@ public Transaction(Identifier referenceBlockId, Identifier sender, Identifier re
     this.amount = amount;
   }
 
+  /**
+   * Return the HashCode.
+   *
+   * @return the hashcode.
+   */
+  @Override
+  public int hashCode() {
+    return this.id().hashCode();
+  }
+
+  /**
+   * Returns true if objects are equal.
+   *
+   * @param o an transaction object.
+   * @return true if objects equal.
+   */
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (!(o instanceof Transaction)) {
+      return false;
+    }
+    Transaction that = (Transaction) o;
+
+    return this.id().equals(that.id());
+  }
+
   /**
    * Type of this entity.
    *

src/main/java/model/lightchain/ValidatedBlock.java

@@ -1,5 +1,7 @@
 package model.lightchain;
 
+import java.util.Arrays;
+
 import model.codec.EntityType;
 import model.crypto.Signature;
 
@@ -36,6 +38,28 @@ public Signature[] getCertificates() {
     return certificates.clone();
   }
 
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (!(o instanceof ValidatedBlock)) {
+      return false;
+    }
+    if (!super.equals(o)) {
+      return false;
+    }
+    ValidatedBlock that = (ValidatedBlock) o;
+    return Arrays.equals(getCertificates(), that.getCertificates());
+  }
+
+  @Override
+  public int hashCode() {
+    int result = super.hashCode();
+    result = 31 * result + Arrays.hashCode(getCertificates());
+    return result;
+  }
+
   @Override
   public String type() {
     return EntityType.TYPE_VALIDATED_TRANSACTION;

src/main/java/model/lightchain/ValidatedTransaction.java

@@ -1,13 +1,16 @@
 package model.lightchain;
 
+import java.io.Serializable;
+import java.util.Arrays;
+
 import model.codec.EntityType;
 import model.crypto.Signature;
 
 /**
  * A ValidatedTransaction is a wrapper around a Transaction that carries a proof of assigned validators that attests
  * the transaction passed local validation of validators.
  */
-public class ValidatedTransaction extends Transaction {
+public class ValidatedTransaction extends Transaction implements Serializable {
   /**
    * Represents the signatures of assigned validators to this transaction.
    */
@@ -36,6 +39,28 @@ public Signature[] getCertificates() {
     return certificates.clone();
   }
 
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (!(o instanceof ValidatedTransaction)) {
+      return false;
+    }
+    if (!super.equals(o)) {
+      return false;
+    }
+    ValidatedTransaction that = (ValidatedTransaction) o;
+    return Arrays.equals(getCertificates(), that.getCertificates());
+  }
+
+  @Override
+  public int hashCode() {
+    int result = super.hashCode();
+    result = 31 * result + Arrays.hashCode(getCertificates());
+    return result;
+  }
+
   @Override
   public String type() {
     return EntityType.TYPE_VALIDATED_TRANSACTION;

src/main/java/storage/Blocks.java

@@ -9,6 +9,8 @@
  * Persistent module for storing blocks on the disk.
  */
 public interface Blocks {
+  // TODO: refactor blocks to keep validated blocks.
+
   /**
    * Checks existence of block on the database.
    *