Starting work on blockchain mining algorithm..

Author: waynewbishop

Source/Extensions/Chain.swift

@@ -10,10 +10,6 @@ import Foundation
 
 
 extension Blockchain {
-
-    
-    //TODO: create a computed property of hashValue to simulate bitcoin mining that
-    //includes some sort of difficulty level..
 
 
     //initialize starting block
@@ -43,4 +39,55 @@ extension Blockchain {
     }
 
 
+    //TODO: estblish new block based on provided input and the level of difficulty.
+    func hashValue(_ element: Block) -> Hash? {
+        
+        var rawvalue = Int()
+        var leadvalue = Int()
+
+        
+        //check tranactions
+        guard let items = element.transactions else {
+            return nil
+        }
+        
+        
+        //sum hash values
+        for exchange in items {
+           rawvalue = exchange.amount.hashValue
+           rawvalue += exchange.from.hashValue
+           rawvalue += exchange.to.hashValue
+           rawvalue += exchange.lastModified.hashValue
+        }
+
+        
+        //sum previous hash
+        if let previous = element.previous {
+            rawvalue += previous.hashValue
+        }
+
+       
+        while leadvalue >= difficulty {
+            
+            print("mining new block..")
+            let testvalue = rawvalue + String(describing: Date()).hashValue
+            
+            let rawlist: Array<Int> = String(testvalue).characters.flatMap{Int(String($0))}
+            
+            for m in 0..<rawlist.startIndex + 3 {
+                leadvalue += rawlist[m]
+            }
+            
+            //perform final bit shift and test leading values
+            if (leadvalue >> 2) >= difficulty {
+                return String(testvalue)
+            }
+            
+        }
+        
+        return nil
+    
+    }
+
+    
 }

Source/Factories/Blockchain.swift

@@ -15,8 +15,9 @@ public class Blockchain: Graph {
     var queue: Queue<Exchange>
 
 
-    let threshold: Int = 0
-    let difficulty: Int = 0
+    //todo: change these to init parameters..
+    let threshold: Int = 3
+    let difficulty: Int = 25
 
 
     //initialize as an undirected graph.
@@ -53,16 +54,18 @@ public class Blockchain: Graph {
                 }
 
 
-                /*
+                 /*
                  note: exchanges are queued before they are
                  added into the main blockchain.
                  */
+                
+                let queue = network.queue
+                let threshold = network.threshold
+                let chain = network.chain
 
+
                 for exchange in peer.intentions {
 
-                    let queue = network.queue
-                    let threshold = network.threshold
-                    
                     //queue items depending on the network threshold. 
                     if queue.count <= threshold {
                         queue.enQueue(exchange)
@@ -78,8 +81,11 @@ public class Blockchain: Graph {
                          asynchronous process.
                          */
 
-                        self.newBlock(for: network)
-                        
+                        if self.newBlock(for: network) != true {
+                            print("unable to create new block..")
+                            return
+                        }
+                                                                        
                         //remove pending transactions
                         peer.intentions.removeAll()
                     }
@@ -91,7 +97,7 @@ public class Blockchain: Graph {
         }
 
 
-        private func newBlock(for network: Blockchain) {
+        private func newBlock(for network: Blockchain) -> Bool {
 
             //esablish queue
             let queue = network.queue
@@ -100,9 +106,9 @@ public class Blockchain: Graph {
 
 
             /*
-             note: dequeue all pending exchanges from the main queue into a single block. now how the
-             queue is a member of the Network not the specific Minder. As a result,
-             other miner instances could theroetically be able to access the shared queue to
+             note: dequeue all pending exchanges from the main queue into a single block. note how the
+             queue is a member of the network a not the specific Miner. As a result,
+             other miner instances could theroetically access the shared queue to
              push exchanges.
             */
 
@@ -114,20 +120,18 @@ public class Blockchain: Graph {
             }
 
 
-            //building the new block
+            //build the new block
             newblock.miner = self
             newblock.previous = network.currentBlock().key
             newblock.transactions = transactions
-            
-            
+            newblock.key = network.hashValue(newblock)
 
             /*
             note: This is also where the hash algorithm for each block obtained. For clarity, make the
             algorithm function an extension.
             */
 
-          
-            
+            return false
         }
 
     }

SwiftStructures.xcodeproj/project.xcworkspace/xcuserdata/waynebishop.xcuserdatad/UserInterfaceState.xcuserstate

@@ -48,12 +48,8 @@ class BlockTest: XCTestCase {
 
     //miners monitor the peer network for intended transactions
     func testMiningBlock() {
-        
         let miner = Blockchain.Miner()
-        
         miner.poll(startingv: PeerA, network: bitcoin)
-        
-        
     }