Merge pull request #1688 from rsksmart/document-remasc-tx

Documented RemascTransaction check usage across the platform

rskj-core/src/main/java/co/rsk/remasc/RemascTransaction.java

@@ -28,7 +28,27 @@
 import static org.ethereum.rpc.TypeConverter.toUnformattedJsonHex;
 
 /**
- * Tx that invokes Remasc's processMinersFees method.
+ * <p>
+ *  Tx that invokes Remasc's processMinersFees method.
+ * </p>
+ * <p>
+ *  Use #{@link Transaction#isRemascTransaction(int, int)} if you have not yet parsed the transaction
+ *  and it is still in binary format.
+ * </p>
+ * <p>
+ *  Use <b></b><i></>instanceOf<i/><b/> to know if a parsed transaction is a remasc transaction.
+ * </p>
+ * <p>
+ * If you would like an easier way to know if a transaction is a Remasc transaction rather than using
+ * #{@link Transaction#isRemascTransaction(int, int)}, you could use:
+ * <blockquote>obj instanceOf RemascTransaction</blockquote>
+ * </p>
+ * <p>
+ * <b>NOTE:</b> Consider that <b></b><i></>instanceOf<i/><b/> only will work if you create an
+ * instance of this class, otherwise using #{@link Transaction#isRemascTransaction(int, int)} is more
+ * recommended and safe.
+ * </p>
+ *
  * @author Oscar Guindzberg
  */
 public class RemascTransaction extends Transaction {

rskj-core/src/main/java/org/ethereum/core/Transaction.java

@@ -532,6 +532,20 @@ public void setLocalCallTransaction(boolean isLocalCall) {
         this.isLocalCall = isLocalCall;
     }
 
+    /**
+     * <p>
+     * Returns true if the current transaction is a Remasc transaction by checking if the transaction position is the
+     * last one, if receive address is equals to #PrecompiledContracts.REMASC_ADDR and finally if there is a signature
+     * and data having value, gas limit and gas price equals to 0, otherwise returns false.
+     * </p>
+     * <p>
+     * Use this method when you don't know if the transaction is a remasc transaction from the parameters given above.
+     * </p>
+     *
+     * @param txPosition transaction position
+     * @param txsSize    transaction size
+     * @return true if the current transaction is a Remasc transaction, otherwise returns false.
+     */
     public boolean isRemascTransaction(int txPosition, int txsSize) {
         return isLastTx(txPosition, txsSize) && checkRemascAddress() && checkRemascTxZeroValues();
     }