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());
+                Cache::set("mineInfo", Blockchain::calculateMineInfo());
 
                 Masternode::resetVerified();
 
@@ -708,6 +708,7 @@ public static function delete($height)
                     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

@@ -30,7 +30,7 @@ static function getAvgBlockTime($blocks) {
 		return $elapsed / $blocks;
 	}
 
-	static function getMineInfo() {
+	static function calculateMineInfo() {
 		global $_config;
 		$diff = Block::difficulty();
 		$current = Block::current();
@@ -55,6 +55,15 @@ static function getMineInfo() {
 		return $res;
 	}
 
+	static function getMineInfo() {
+		$info = Cache::get("mineInfo");
+		if(empty($info)) {
+			$info = Blockchain::calculateMineInfo();
+			Cache::set("mineInfo", $info);
+		}
+		return $info;
+	}
+
 	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();