get token_limit from database

cache token_limit

private/app/php/cache.php

@@ -0,0 +1,83 @@
+<?php
+function get_token_limit(){
+
+	/*
+	update every 30 min
+	*/ 
+
+	$update = apcu_add("time", false, 1800);
+	if ($update) {
+
+		apcu_store("update", true, 10);
+		usleep(100 * 1000); 
+		error_log("update cache");
+		update_cache();
+		apcu_delete("update");
+	}
+
+
+	while (apcu_fetch("update")) {
+		usleep(30 * 1000);
+	}
+	$token_limit = apcu_fetch("token_limit");
+	$index = apcu_fetch($_SESSION['username']);
+	$index_status = apcu_fetch("STUDENT"); #$_SESSION['status']
+
+
+    if (has_tokenlimit($token_limit, $index)) {
+
+        return $token_limit[$index]['token_limit'];
+    }
+
+    if (is_int($index_status)) {
+        return $token_limit[$index_status]['token_limit'];
+    }
+
+    return getenv("TOKEN_LIMIT");
+
+}
+
+function update_cache() {
+    $host = getenv("DB_HOST");
+	$db = getenv("DB_DB");
+	$table = getenv('DB_TABLE_LIMIT');
+	$user = getenv("DB_USER");
+	$pass = getenv("DB_PASS");
+	$port = getenv("DB_PORT");
+	$dsn = "pgsql:host=$host;port=$port;dbname=$db";
+
+	try {
+ 		$pdo = new PDO($dsn, $user, $pass);
+ 		$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
+		$sql = "SELECT username,token_limit FROM $table WHERE valid_till >= :datum";
+	    $stmt = $pdo->prepare($sql);
+		$stmt->bindParam(':datum', $datum);
+		$datum = date("Y-m-d");
+	    $stmt->execute();
+	    $result = $stmt->fetchAll(PDO::FETCH_ASSOC);
+
+		apcu_store("token_limit", $result, 3600);
+		for ($i=0; $i < count($result); $i++) {
+			apcu_store($result[$i]['username'], $i, 3600);
+		}
+
+
+	} catch (PDOException $e) {
+	    error_log($e->getMessage());
+	    exit;
+	}
+
+}
+
+function has_tokenlimit ($token_limit, $index) {
+	if (! ($token_limit && is_int($index))) {
+		return false;
+	}
+
+	if ($token_limit[$index]['username'] != $_SESSION['username']) {
+		apcu_delete($_SESSION['username']);
+		return false;
+	}
+
+	return true;
+}

private/app/php/stream-api.php

@@ -5,6 +5,7 @@
 }
 
 require_once BOOTSTRAP_PATH;
+require_once 'cache.php';
 
 session_start();
 if (!isset($_SESSION['username'])) {
@@ -179,7 +180,7 @@ function update_separated_token($prompt_tokens, $completion_tokens, $total_token
 }
 
 function check_token_limit(){
-	$max_tokens = getenv("TOKEN_LIMIT");
+	$max_tokens = get_token_limit();
 	if ($max_tokens <= 0) {
 		return;
 	}