Logging the user's IP with log4php

Is there anyway to have it include the user's IP address, PHPSESSIONID, URL, and filename/linenumber? These things are very useful - more than a PID etc in PHP.

log4php overhead

A key requirement of loggers is to stay out of the way when not needed - that is, not to slow things down. Java's log4j fulfills this admirably. Unlike in Java, where the initial overhead is one time only and hence minimal, PHP's overhead is constantly repeated froms scratch, due to the fact that