v6 initial commit, maybe more to follow

blockchain/block.js

@@ -0,0 +1,58 @@
+const ChainUtil = require('../chain-util');
+const { DIFFICULTY, MINE_RATE } = require('../config');
+
+class Block {
+  constructor(timestamp,BlockNum, lastHash, hash, data, nonce, 
+              difficulty) {
+    this.timestamp = timestamp;
+    this.BlockNum  = BlockNum;
+    this.lastHash = lastHash;
+    this.hash = hash;
+    this.data = data;
+    this.nonce = nonce;
+    this.difficulty = difficulty || DIFFICULTY;
+  }
+  toString() {
+    return `Block -
+      Timestamp : ${this.timestamp}
+      BlockNum  : ${this.BlockNum}
+      Last Hash : ${this.lastHash.substring(0, 10)}
+      Hash      : ${this.hash.substring(0, 10)}
+      Nonce     : ${this.nonce}
+      Difficulty: ${this.difficulty}
+      Data      : ${this.data[0].length}`;
+  }
+  static genesis() {
+    return new this('Genesis-time',0, '-----', 'First-Hash', 
+                    [], 0, DIFFICULTY);
+  }
+  static mineBlock(lastBlock, data) {
+    let hash, timestamp;
+    const lastHash = lastBlock.hash;
+    let { difficulty } = lastBlock;
+    let nonce = 0;
+    let BlockNum = lastBlock.BlockNum + 1;
+    do {
+      nonce++;
+      timestamp = Date.now();
+      difficulty = Block.adjustDifficulty(lastBlock, timestamp);
+      hash = Block.hash(timestamp, lastHash, data, nonce, difficulty);
+    } while (hash.substring(0, difficulty) !== '0'.repeat(difficulty));
+      return new this(timestamp,BlockNum, lastHash, hash, data, nonce, 
+      difficulty);}
+  static hash(timestamp,lastHash, data, nonce, difficulty) {
+    return ChainUtil.hash(`${timestamp}${lastHash}${data}${nonce}
+                           ${difficulty}`).toString();
+  }
+  static blockHash(block) {
+    const { timestamp, lastHash, data, nonce, difficulty } = block;
+    return Block.hash(timestamp, lastHash, data, nonce, difficulty);
+  }
+  static adjustDifficulty(lastBlock, currentTime) {
+    let { difficulty } = lastBlock;
+    difficulty = lastBlock.timestamp + MINE_RATE > currentTime ?
+      difficulty + 1 : difficulty - 1;
+    return difficulty;
+  }
+}
+module.exports = Block;