How it works

Author: Takaki Hamada

how to add original function like test_cipher

In the SQLite3 implementations, it converts input SQL query into bytecode. And, SQLite3 executes compiled byteode on VDBE (Vertual DataBase Engine), that is vertual machine manipulates table row data on B-Tree. By this vertual machine, the function calling query is processed as Function Opecode.

There are a function sqlite3RegisterBuiltinFunction and a macro TEST_FUNC, which are used to define the Function Opecode (e.g. length, max, min...). To realize PKSE searching function, we defined the operation of test_cipher and called TEST_FUNC in sqlite3RegisterBuiltinFunction.

Our test_cipher implementation is here.