daktylos/libs/JsonDatabase.class.php

<?php
class JsonDatabase {
	public function read($filename) {
		$fileContents = file_get_contents(DATA_PATH . $filename);
		return json_decode($fileContents, true);
	}

	public function write($filename, $dataToMerge) {
		$originalData = $this->read($filename);
		$mergedData = array_merge($originalData, $dataToMerge);
		$fileHandle = fopen(DATA_PATH . $filename, "w");
		$fileText = json_encode($mergedData, true);
		fwrite($fileHandle, $fileText);
		fclose($fileHandle);
	}
}