Processing CSV files in a memory efficient way
A little while ago I had to dive deeper into the performance optimized usage of PHPExcel. Our users are uploading files like Excel or CSV with a lot data to process. Initially we used the PHPEXcel instance without any tuning of the default configuration which lead to heavy memory issues on relativly small files. So I had to avoid reading all file content at ones to the buffer (like file_get_contents() does).