rename canBeChained to validLinkBetween

fluency03 · Apr 27, 2018 · b2fc78b · b2fc78b
1 parent 4a6256f
commit b2fc78b
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Showing 2 changed files with 32 additions and 9 deletions.
diff --git a/src/main/scala/com/fluency03/blockchain/core/Block.scala b/src/main/scala/com/fluency03/blockchain/core/Block.scala
@@ -1,6 +1,7 @@
 package com.fluency03.blockchain
 package core
 
+import com.fluency03.blockchain.core.Block.allTransValidOf
 import com.fluency03.blockchain.core.BlockHeader.hashOfHeaderFields
 import com.fluency03.blockchain.core.Transaction.{createCoinbaseTx, validateCoinbaseTx, noDuplicateTxInOf}
 import org.json4s.native.JsonMethods.{compact, render}
@@ -39,10 +40,11 @@ case class Block(header: BlockHeader, transactions: Seq[Transaction], hash: Stri
 
   def hasValidHeaderHash: Boolean = hash == header.hash
 
-  def allTransactionsValid(uTxOs: mutable.Map[Outpoint, TxOut]): Boolean = transactions match {
-    case Nil => false
-    case init :+ last => validateCoinbaseTx(last, index) && init.forall(tx => tx.isValid(uTxOs))
-  }
+  def allTransAreValid(uTxOs: mutable.Map[Outpoint, TxOut]): Boolean = allTransValidOf(transactions, index, uTxOs)
+//    transactions match {
+//    case Nil => false
+//    case init :+ last => validateCoinbaseTx(last, index) && init.forall(tx => tx.isValid(uTxOs))
+//  }
 
   def noDuplicateTxIn(): Boolean = noDuplicateTxInOf(transactions)
 
@@ -121,10 +123,31 @@ object Block {
       transactions: Seq[Transaction]): Block =
     mineNextBlock(currentBlock.index + 1, currentBlock.hash, newBlockData, timestamp, difficulty, transactions)
 
-  // TODO (Chang): Check transactions in the new block?
-  def canBeChained(newBlock: Block, previousBlock: Block): Boolean =
-    previousBlock.index + 1 == newBlock.index && previousBlock.hash == newBlock.previousHash && newBlock.hasValidHash
+  /**
+   * Check whether transactions of a Block are valid:
+   * 1. Coinbase transaction is valid
+   * 2. Rest of the transactions are valid
+   * 3. if the Seq is empty, then it is not valid, because it has to at least contain one coinbase transaction
+   */
+  def allTransValidOf(
+      transactions: Seq[Transaction],
+      blockIndex: Int,
+      uTxOs: mutable.Map[Outpoint, TxOut])
+    : Boolean = transactions match {
+    case Nil => false
+    case init :+ last => validateCoinbaseTx(last, blockIndex) && init.forall(tx => tx.isValid(uTxOs))
+  }
 
+  /**
+   * Check whether a new Block can be chained to the last Block of a Blockchain (previousBlock of newBlock):
+   * 1. New Block's index should be the previous index plus one
+   * 2. New Block's previousHash should be the hash of previous Block
+   * 3. New Block should have valid hash (that means, valid header hash and merkle hash)
+   */
+  def validLinkBetween(newBlock: Block, previousBlock: Block): Boolean =
+    previousBlock.index + 1 == newBlock.index &&
+      previousBlock.hash == newBlock.previousHash &&
+      newBlock.hasValidHash
 
 
 }

diff --git a/src/main/scala/com/fluency03/blockchain/core/Blockchain.scala b/src/main/scala/com/fluency03/blockchain/core/Blockchain.scala
@@ -1,7 +1,7 @@
 package com.fluency03.blockchain
 package core
 
-import com.fluency03.blockchain.core.Block.canBeChained
+import com.fluency03.blockchain.core.Block.validLinkBetween
 import com.fluency03.blockchain.core.Blockchain._
 import org.json4s.native.JsonMethods.{compact, render}
 import org.json4s.{Extraction, JValue}
@@ -51,7 +51,7 @@ object Blockchain {
   def isValidChain(chain: Seq[Block]): Boolean = chain match {
     case Nil => true
     case g +: Nil => g.previousHash == ZERO64 && g.index == 0 && g.hasValidHash
-    case a +: b +: tail => canBeChained(a, b) && isValidChain(b +: tail)
+    case a +: b +: tail => validLinkBetween(a, b) && isValidChain(b +: tail)
   }
 
 }