Python bindings for the Relooper library

relooper.py

"""
Wrapper for the Relooper api.
"""

"""
RELOOPERDLL_API void  rl_set_output_buffer(char *buffer, int size);
RELOOPERDLL_API void  rl_make_output_buffer(int size);
RELOOPERDLL_API void *rl_new_block(const char *text);
RELOOPERDLL_API void  rl_delete_block(void *block);
RELOOPERDLL_API void  rl_block_add_branch_to(void *from, void *to, const char *condition, const char *code);
RELOOPERDLL_API void *rl_new_relooper();
RELOOPERDLL_API void  rl_delete_relooper(void *relooper);
RELOOPERDLL_API void  rl_relooper_add_block(void *relooper, void *block);
RELOOPERDLL_API void  rl_relooper_calculate(void *relooper, void *entry);
RELOOPERDLL_API void  rl_relooper_render(void *relooper);
"""

import os
from ctypes import *

lib = cdll[os.path.dirname(__file__) + "/librelooper.so"]

class Relooper:
	r"""
	Basic usage:

	>>> import relooper
	>>> rl = relooper.Relooper()
	>>> b1 = relooper.Block("Swag")
	>>> rl.add_block(b1)
	>>> rl.calculate(b1)
	'Swag\n'

	An example from test.cpp of the Relooper source, adapted for Python:
	>>> import relooper
	>>> b_a = relooper.Block("// block A\n")
	>>> b_b = relooper.Block("// block B\n")
	>>> b_c = relooper.Block("// block C\n")
	>>> b_a.add_branch_to(b_b, "check == 10", "atob();")
	>>> b_a.add_branch_to(b_c, None, "atoc();");
	>>> b_b.add_branch_to(b_c, None, "btoc();");
	>>> r = relooper.Relooper()
	>>> r.add_block(b_a)
	>>> r.add_block(b_b)
	>>> r.add_block(b_c)
	>>> print(r.calculate(b_a))
	// block A
	if (check == 10) {
	  atob();
	  // block B
	  btoc();
	} else {
	  atoc();
	}
	// block C
	<BLANKLINE>
	"""

	def __init__(self):
		self.native_ptr = lib.rl_new_relooper();
	def __del__(self):
		lib.rl_delete_relooper(self.native_ptr)
	def add_block(self, block):
		lib.rl_relooper_add_block(self.native_ptr, block.native_ptr)
		block.added = True
	def calculate(self, entry):
		lib.rl_relooper_calculate(self.native_ptr, entry.native_ptr)
		mybuffer = create_string_buffer(0x10000)
		lib.rl_set_output_buffer(mybuffer, len(mybuffer))
		lib.rl_relooper_render(self.native_ptr)
		return mybuffer.value.decode('utf-8')

class Block:
	def __init__(self, text):
		self.native_ptr = lib.rl_new_block(bytes(text, 'utf-8'))
	def __del__(self):
		if not self.added:
			lib.rl_delete_block(self.native_ptr)
	def add_branch_to(self, to_block, condition, code):
		lib.rl_block_add_branch_to(self.native_ptr, to_block.native_ptr, bytes(condition, 'utf-8') if not condition is None else None,
			bytes(code, 'utf-8') if not code is None else None)