1. A streaming program compiler for compiling a streaming program, said compiler comprising: an operation module for calling a dynamic link library (DLL) during execution of said streaming program; an association table generating unit for generating an association table according to a user-defined rule, wherein said association table includes an entry indicating (i) a stream branch of said streaming program and (ii) an operation module corresponding to said stream branch; and a trigger generating unit for generating a trigger based on said user-defined rule, wherein said trigger generating unit (i) determines which condition for loading and unloading dynamic link libraries fits said streaming program, (ii) matches said condition to a particular stream branch to identify a matched stream branch, and (iii) sends out a triggering signal indicating the matched stream branch.