How to use the cffi.verifier.Verifier function in cffi

r->m_numInvokes = count;
    }

    /* Logging */
    #include 

    void (*python_log_callback)(int level, char *msg);
    void c_log_callback(int level, const char *fmt, va_list args) {
        char buf[2048];
        vsprintf(buf, fmt, args);
        python_log_callback(level, buf);
    }

"""

verifier = Verifier(ffi, preamble, libraries=["rtmp"],
                    ext_package="librtmp_ffi", modulename="_binding",
                    sources=["src/librtmp/amf.c"])

def test_write_source(self):
        ffi = FFI()
        ffi.cdef("double sin(double x);")
        csrc = '/*hi there %s!*/\n#include \n' % self
        v = Verifier(ffi, csrc, force_generic_engine=self.generic,
                     libraries=[self.lib_m])
        v.write_source()
        with open(v.sourcefilename, 'r') as f:
            data = f.read()
        assert csrc in data

def test_compile_module_explicit_filename(self):
        ffi = FFI()
        ffi.cdef("double sin(double x);")
        csrc = '/*hi there %s!2*/\n#include \n' % self
        v = Verifier(ffi, csrc, force_generic_engine=self.generic,
                     libraries=[self.lib_m])
        basename = self.__class__.__name__ + 'test_compile_module'
        v.modulefilename = filename = str(udir.join(basename + '.so'))
        v.compile_module()
        assert filename == v.modulefilename
        assert v.get_module_name() == basename
        if v.generates_python_module():
            mod = imp.load_dynamic(v.get_module_name(), v.modulefilename)
            assert hasattr(mod, '_cffi_setup')

def test_verifier_args(self):
        ffi = FFI()
        ffi.cdef("double sin(double x);")
        csrc = '/*hi there %s!4*/#include "test_verifier_args.h"\n' % self
        udir.join('test_verifier_args.h').write('#include \n')
        v = Verifier(ffi, csrc, include_dirs=[str(udir)],
                     force_generic_engine=self.generic,
                     libraries=[self.lib_m])
        library = v.load_library()
        assert library.sin(12.3) == math.sin(12.3)

# case that anonymous enums would produce '$enum_$1', which was
    # used as part of a function name.  GCC accepts such names, but it's
    # apparently non-standard.
    _r_comment = re.compile(r"/\*.*?\*/|//.*?$", re.DOTALL | re.MULTILINE)
    _r_string = re.compile(r'\".*?\"')
    def _write_source_and_check(self, file=None):
        base_write_source(self, file)
        if file is None:
            f = open(self.sourcefilename)
            data = f.read()
            f.close()
            data = _r_comment.sub(' ', data)
            data = _r_string.sub('"skipped"', data)
            assert '$' not in data
    base_write_source = cffi.verifier.Verifier._write_source
    cffi.verifier.Verifier._write_source = _write_source_and_check

def test_load_library(self):
        ffi = FFI()
        ffi.cdef("double sin(double x);")
        csrc = '/*hi there %s!3*/\n#include \n' % self
        v = Verifier(ffi, csrc, force_generic_engine=self.generic,
                     libraries=[self.lib_m])
        library = v.load_library()
        assert library.sin(12.3) == math.sin(12.3)

_FILE_PATH = os.path.dirname(os.path.realpath(__file__))
os.chdir(_FILE_PATH)
os.chdir(os.pardir)

#use the absolute path to load the file here so we don't have to worry about working directory issues
_CDEF = open("{}/py_fourd.h".format(_FILE_PATH)).read()

ffi.cdef(_CDEF)

_SOURCE = """
#include "fourd.h"
"""

source_files = glob.glob('lib4d_sql/*.c')

ffi.verifier = Verifier(ffi, _SOURCE,
                       modulename=_create_modulename(_CDEF, _SOURCE, sys.version),
                       sources=source_files,
                       include_dirs=['lib4d_sql', 'py4d/lib4d_sql'])

#ffi.verifier.compile_module = _compile_module
#ffi.verifier._compile_module = _compile_module

lib4d_sql = LazyLoadLib(ffi)
os.chdir(_CWD)

########################################################################


########################################################################
## Error Classes
########################################################################

int crypto_hash_sha512(unsigned char *out, const unsigned char *in, unsigned long long inlen);
    """

    # Secure Random
    """
        void randombytes(unsigned char * const buf, const unsigned long long buf_len);
    """

    # Low Level - Scalar Multiplication
    """
        int crypto_scalarmult_curve25519_base(unsigned char *q, const unsigned char *n);
    """
)


ffi.verifier = cffi.verifier.Verifier(ffi,
    "#include ",

    # We need to link to the sodium library
    libraries=["sodium"],

    # Our ext_package is nacl so look for it
    ext_package="nacl",
)


# This works around a bug in PyPy where CFFI exposed functions do not have a
# __name__ attribute. See https://bugs.pypy.org/issue1452
def wraps(wrapped):
    def inner(func):
        if hasattr(wrapped, "__name__"):
            return functools.wraps(wrapped)(func)