main class

Author: sujanshsh

SQLite3DataCache.php

@@ -0,0 +1,76 @@
+<?php
+
+class SQLite3DataCache
+{
+    private $sqlite3_db; //SQLite3 db
+
+    public function __construct() {
+        $target_directory = __DIR__.'/../../cache_files';
+        $file_name = 'cache.sqlite3db';
+        if (!file_exists($target_directory) && !mkdir($target_directory, 0777, true)) {
+            die('Failed to create folder/file');
+        }
+        $this->sqlite3_db = new SQLite3($target_directory.'/'.$file_name,SQLITE3_OPEN_CREATE|SQLITE3_OPEN_READWRITE);
+        $stmt = @$this->sqlite3_db->prepare("SELECT * FROM cache");
+        if($stmt===false) {
+            $this->sqlite3_db->exec("CREATE TABLE cache
+                (server_name VARCHAR(35),
+                key VARCHAR(40),
+                value VARCHAR(100),
+                valid_upto_unixtime INTEGER)");
+        }
+    }
+    
+    public function get($key) {
+        $cur_unixtime = time();
+        $output = [];
+        $output['value'] = false;
+        $output['available'] = false;
+        $key = $this->sqlite3_db->escapeString($key);
+        // fetch only first column, only single row
+        $result = $this->sqlite3_db->querySingle("
+            SELECT value from cache where key='$key' and 
+            (valid_upto_unixtime=0 or valid_upto_unixtime>=$cur_unixtime)");
+        if($result===false) {
+            $output['message'] = 'cache query error';
+            return $output;
+        }
+        if($result===null) { // empty array is returned if all columns fetched
+            return $output;
+        }
+        $output['available'] = true;
+        $output['value'] = $result;
+        return $output;
+    }
+    
+    public function set($key,$value,$valid_upto = 0) {
+        $key = $this->sqlite3_db->escapeString($key);
+        $value = $this->sqlite3_db->escapeString($value);
+
+        $result = $this->sqlite3_db->exec("
+            DELETE FROM cache WHERE server_name = '{$_SERVER['SERVER_NAME']}'
+            and key='$key'");
+        
+        if($result===false)
+            return false;
+        
+        $result = $this->sqlite3_db->exec("
+            INSERT INTO cache VALUES ('{$_SERVER['SERVER_NAME']}',
+        '$key','$value',$valid_upto )");
+        return $result;
+    }
+    
+    public function delete($key) {
+        $key = $this->sqlite3_db->escapeString($key);
+        $value = $this->sqlite3_db->escapeString($value);
+        $result = $this->sqlite3_db->exec("
+            DELETE FROM cache WHERE key = '$key' ");
+        return $result;
+    }
+    
+    public function __destruct() {
+        $this->sqlite3_db->close();
+    }
+
+}
+