feat(nodeminer): Cache block info to speed up mining

include/class/Block.php

@@ -191,7 +191,7 @@ public function add(&$error = null, $syncing=false)
                 Cache::set("current", $this->toArray());
                 Cache::set("height", $this->height);
                 Cache::set("current_export", Block::export($hash));
-                Cache::set("mineInfo", Blockchain::getMineInfo());
+                Blockchain::invalidateMineInfo();
 
                 Masternode::resetVerified();
 
@@ -704,10 +704,11 @@ public static function delete($height)
                     }
 
                     Masternode::resetVerified();
+                    Blockchain::invalidateMineInfo();
                     Cache::remove("current");
-                    Cache::remove("mineInfo");
                     Cache::remove("height");
                     Cache::remove("current_export");
+                    Cache::remove("mineInfo");
 
                 } catch (Exception $e) {
                     _log("Error locking delete blocks ".$e->getMessage());

include/class/Blockchain.php

@@ -3,6 +3,7 @@
 
 class Blockchain
 {
+	static $mineInfo;
 
 	static function getHashRate($blocks) {
 		$blockCount = Block::getHeight();
@@ -31,28 +32,34 @@ static function getAvgBlockTime($blocks) {
 	}
 
 	static function getMineInfo() {
-		global $_config;
-		$diff = Block::difficulty();
-		$current = Block::current();
-		$reward = Block::reward($current['height']+1);
-		$res = [
-			"difficulty" => $diff,
-			"block"      => $current['id'],
-			"height"     => $current['height'],
-			"date"=>$current['date'],
-			"data"=>[],
-			"time"=>time(),
-			"reward"=>num($reward['miner']),
-			"version"=>Block::versionCode($current['height']+1),
-			"generator"=>Account::getAddress($_config['generator_public_key']),
-			"ip"=>@$_SERVER['SERVER_ADDR'],
-			"hashingOptions"=>Block::hashingOptions($current['height']+1),
-			"fee"=>Blockchain::getFee(),
-			"network"=>NETWORK,
-			"chain_id"=>CHAIN_ID
-		];
-//		_log("getMineInfo: ".json_encode($res), 5);
-		return $res;
+		if(empty(self::$mineInfo)) {
+			global $_config;
+			$diff = Block::difficulty();
+			$current = Block::current();
+			$reward = Block::reward($current['height']+1);
+			$res = [
+				"difficulty" => $diff,
+				"block"      => $current['id'],
+				"height"     => $current['height'],
+				"date"=>$current['date'],
+				"data"=>[],
+				"time"=>time(),
+				"reward"=>num($reward['miner']),
+				"version"=>Block::versionCode($current['height']+1),
+				"generator"=>Account::getAddress($_config['generator_public_key']),
+				"ip"=>@$_SERVER['SERVER_ADDR'],
+				"hashingOptions"=>Block::hashingOptions($current['height']+1),
+				"fee"=>Blockchain::getFee(),
+				"network"=>NETWORK,
+				"chain_id"=>CHAIN_ID
+			];
+			self::$mineInfo = $res;
+		}
+		return self::$mineInfo;
+	}
+
+	static function invalidateMineInfo() {
+		self::$mineInfo = null;
 	}
 
 	static function addBlock(Block $block) {

include/class/Cache.php

@@ -29,7 +29,7 @@ static function get($key, $default = null) {
 		if(file_exists($cache_file)) {
 			$content = file_get_contents($cache_file);
 			$res = json_decode($content, true);
-			if($res) {
+			if (json_last_error() === JSON_ERROR_NONE) {
 				return $res;
 			}
 		}

include/class/NodeMiner.php

@@ -149,18 +149,12 @@ function start($mine_blocks = null, $sleep = 3) {
 
 				_log("Mining attempt={$this->attempt} height=$height difficulty=$difficulty elapsed=$elapsed hit=$hit target=$target speed={$this->speed} blockFound=$blockFound", 3);
 				$this->miningStat['hashes']++;
-				$mod = 10+$this->cpu;
-				if($this->attempt % $mod == 0) {
-					$info = $this->getMiningInfo();
-					if($info!==false) {
-						_log("Checking new block from server ".$info['block']. " with our block $prev_block_id", 4);
-						if($info['block']!= $prev_block_id) {
-							_log("New block received", 3);
-							$this->miningStat['dropped']++;
-							break;
-						}
-					}
-				}
+                $info = $this->getMiningInfo();
+                if ($info['block'] != $prev_block_id) {
+                    _log("New block received", 3);
+                    $this->miningStat['dropped']++;
+                    break;
+                }
 
                 $send_interval = 60;
                 $t=time();

miner.speedup.md

@@ -0,0 +1,25 @@
+# Miner Speedup
+
+This document explains the changes made to speed up the nodeminer.
+
+## Problem
+
+The nodeminer was slow to start working on a new block because it only checked for a new block periodically. This meant that the miner could be wasting time trying to mine a block that was already found by another miner.
+
+## Solution
+
+The solution was to make the miner check for a new block after every hash. This was made possible by implementing an in-memory cache for the mining information.
+
+### In-Memory Cache
+
+An in-memory cache was implemented using a static variable in the `Blockchain` class. This makes getting the mining information extremely fast, as it does not require any database or filesystem access.
+
+The `Blockchain::getMineInfo()` method was refactored to use this in-memory cache. A new method, `Blockchain::invalidateMineInfo()`, was added to clear the cache.
+
+### Cache Invalidation
+
+The cache is invalidated whenever the blockchain changes. This is done by calling `Blockchain::invalidateMineInfo()` in the `Block::add()` and `Block::delete()` methods.
+
+### Miner Update
+
+The `NodeMiner` was updated to call `Blockchain::getMineInfo()` after every hash. This allows the miner to quickly detect when a new block has been found and to start working on the next block immediately.