Setup API requests limit system.

classes/APILimits.php

@@ -0,0 +1,135 @@
+<?php
+/**
+ * API Actions limits count
+ * 
+ * @author Pierre HUBERT
+ */
+
+class APILimits {
+
+	/**
+	 * Table name
+	 */
+	const TABLE_NAME = DBprefix."api_limit_count";
+
+	/**
+	 * Entries live time
+	 */
+	const KEEP_DATA_FOR = 3600; // 1 hour
+
+	/**
+	 * Actions list
+	 */
+	const ACTION_LOGIN_FAILED = "failed_login";
+
+	/**
+	 * Actions configruation
+	 */
+	const ACTIONS = array(
+
+		//Login failed
+		self::ACTION_LOGIN_FAILED => array(
+			"limit" => 10
+		)
+	);
+
+	/**
+	 * Limit the number of time a client can perform a query over the API
+	 * 
+	 * @param string $action The name of the action to limit
+	 * @param bool $trigger Specify whether this call of the method must be
+	 * considered as a call of the client or not
+	 */
+	public function limit_query(string $action, bool $trigger){
+
+		//First, clean old entries
+		$this->clean();
+
+		$ip = $_SERVER["REMOTE_ADDR"];
+
+		//If required, increase action by one
+		if($trigger)
+			$this->trigger($action, $ip);
+		
+		//Count the number of time the action occurred
+		if($this->count($action, $ip) > self::ACTIONS[$action]["limit"])
+			Rest_fatal_error(429, "Too many request. Please try again later.");
+	}
+
+	/**
+	 * Clean old entries
+	 */
+	public function clean(){
+		db()->deleteEntry(
+			self::TABLE_NAME,
+			"time_start < ?",
+			array(time() - self::KEEP_DATA_FOR)
+		);
+	}
+
+	/**
+	 * Increase by one the number of the time a client performed
+	 * an action
+	 * 
+	 * @param string $action The action to trigger
+	 * @param string $ip The target IP address
+	 * @return bool TRUE for a success else FALSE
+	 */
+	private function trigger(string $action, string $ip) : bool {
+
+		if(!$this->exists($action, $ip)){
+			return db()->addLine(self::TABLE_NAME, array(
+				"ip" => $ip,
+				"time_start" => time(),
+				"action" => $action,
+				"count" => 1
+			));
+		}
+
+		else {
+			
+			$number = $this->count($action, $ip);
+			$number++;
+
+			return db()->updateDB(self::TABLE_NAME,
+				"ip = ? AND action = ?",
+				array("count" => $number),
+				array($ip, $action));
+		}
+
+	}
+
+	/**
+	 * Check wether an action has been referenced at least once in
+	 * the database
+	 * 
+	 * @param string $action The action to check
+	 * @param string $ip The target IP address
+	 * @return bool TRUE if the entry has been found at least once / FALSE else
+	 */
+	private function exists(string $action, string $ip) : bool {
+		return db()->count(self::TABLE_NAME, 
+			"WHERE ip = ? AND action = ?",
+			array($ip, $action)) > 0;
+	}
+
+	/**
+	 * Count the number of time an IP address has performed an action
+	 * 
+	 * @param string $action The target action
+	 * @param string $ip Target IP address
+	 * @return int The number of time the action has been done
+	 */
+	private function count(string $action, string $ip) : int {
+		$data = db()->select(self::TABLE_NAME, 
+			"WHERE ip = ? AND action = ?",
+			array($ip, $action),
+			array("count"));
+		
+		if(count($data) < 1)
+			return 1;
+		
+		else
+			return $data[0]["count"];
+	}
+}