Safe and unsafe FFI slowdown compare to C

c.c

#include <whitedb/dbapi.h>

int main(int argc, char **argv) {
	void *db, *rec;
	wg_int enc;
	db = wg_attach_database("233", 1000000000);

	char *str = "Hello, world";

	for (int i = 0; i < 10000000; i++) {
		rec = wg_create_record(db, 1);
		enc = wg_encode_str(db, str, NULL);
		wg_set_field(db, rec, 0, enc);
	}

	wg_detach_database(db);
	return 0;
}

result

/usr/bin/time -v ./c
	Command being timed: "./c"
	User time (seconds): 1.16
	System time (seconds): 0.63
	Percent of CPU this job got: 99%
	Elapsed (wall clock) time (h:mm:ss or m:ss): 0:01.80
	Average shared text size (kbytes): 0
	Average unshared data size (kbytes): 0
	Average stack size (kbytes): 0
	Average total size (kbytes): 0
	Maximum resident set size (kbytes): 725920
	Average resident set size (kbytes): 0
	Major (requiring I/O) page faults: 0
	Minor (reclaiming a frame) page faults: 181535
	Voluntary context switches: 1
	Involuntary context switches: 186
	Swaps: 0
	File system inputs: 0
	File system outputs: 0
	Socket messages sent: 0
	Socket messages received: 0
	Signals delivered: 0
	Page size (bytes): 4096
	Exit status: 0


/usr/bin/time -v ./UnsafeFFI
	Command being timed: "./UnsafeFFI"
	User time (seconds): 1.24
	System time (seconds): 0.63
	Percent of CPU this job got: 99%
	Elapsed (wall clock) time (h:mm:ss or m:ss): 0:01.89
	Average shared text size (kbytes): 0
	Average unshared data size (kbytes): 0
	Average stack size (kbytes): 0
	Average total size (kbytes): 0
	Maximum resident set size (kbytes): 726704
	Average resident set size (kbytes): 0
	Major (requiring I/O) page faults: 0
	Minor (reclaiming a frame) page faults: 181801
	Voluntary context switches: 1
	Involuntary context switches: 196
	Swaps: 0
	File system inputs: 0
	File system outputs: 0
	Socket messages sent: 0
	Socket messages received: 0
	Signals delivered: 0
	Page size (bytes): 4096
	Exit status: 0



/tmp/tmproot/bin/time -v ./SafeFFI
	Command being timed: "./SafeFFI"
	User time (seconds): 3.42
	System time (seconds): 0.70
	Percent of CPU this job got: 99%
	Elapsed (wall clock) time (h:mm:ss or m:ss): 0:04.13
	Average shared text size (kbytes): 0
	Average unshared data size (kbytes): 0
	Average stack size (kbytes): 0
	Average total size (kbytes): 0
	Maximum resident set size (kbytes): 726448
	Average resident set size (kbytes): 0
	Major (requiring I/O) page faults: 0
	Minor (reclaiming a frame) page faults: 181796
	Voluntary context switches: 1
	Involuntary context switches: 429
	Swaps: 0
	File system inputs: 0
	File system outputs: 0
	Socket messages sent: 0
	Socket messages received: 0
	Signals delivered: 0
	Page size (bytes): 4096
	Exit status: 0

SafeFFI.hs

{-# LANGUAGE ForeignFunctionInterface #-}
import Foreign
import Foreign.C

data WhiteDB
data Record

foreign import ccall "wg_attach_database" c_wg_attach_database  :: CString -> CInt -> IO (Ptr WhiteDB)
foreign import ccall "wg_detach_database" c_wg_detach_database :: Ptr WhiteDB -> IO CInt

foreign import ccall "wg_create_record"   c_wg_create_record   :: Ptr WhiteDB -> CInt -> IO (Ptr Record)

foreign import ccall "wg_set_field"       c_wg_set_field       :: Ptr WhiteDB -> Ptr Record -> CInt -> CInt -> IO CInt

foreign import ccall "wg_int wg_encode_str" c_wg_encode_str :: Ptr WhiteDB -> CString -> CInt -> IO CInt
foreign import ccall "wg_int wg_decode_str" c_wg_decode_str :: Ptr WhiteDB -> CInt -> IO CString

main :: IO ()
main = do
    name <- newCString "233"
    db <- c_wg_attach_database name 1000000000

    cstr  <- newCString "Hello, world"
    loop db cstr (10000000 :: Int)

    c_wg_detach_database db
    return ()

 where
   loop db cstr 0 = return ()
   loop db cstr n = do
       re  <- c_wg_create_record db 1
       enc <- c_wg_encode_str db cstr 0
       c_wg_set_field db re 0 enc
       loop db cstr (n - 1)

UnsafeFFI.hs

{-# LANGUAGE ForeignFunctionInterface #-}
import Foreign
import Foreign.C

data WhiteDB
data Record

foreign import ccall unsafe "wg_attach_database" c_wg_attach_database  :: CString -> CInt -> IO (Ptr WhiteDB)
foreign import ccall unsafe "wg_detach_database" c_wg_detach_database :: Ptr WhiteDB -> IO CInt

foreign import ccall unsafe "wg_create_record"   c_wg_create_record   :: Ptr WhiteDB -> CInt -> IO (Ptr Record)

foreign import ccall unsafe "wg_set_field"       c_wg_set_field       :: Ptr WhiteDB -> Ptr Record -> CInt -> CInt -> IO CInt

foreign import ccall unsafe "wg_int wg_encode_str" c_wg_encode_str :: Ptr WhiteDB -> CString -> CInt -> IO CInt
foreign import ccall unsafe "wg_int wg_decode_str" c_wg_decode_str :: Ptr WhiteDB -> CInt -> IO CString

main :: IO ()
main = do
    name <- newCString "233"
    db <- c_wg_attach_database name 1000000000

    cstr  <- newCString "Hello, world"
    loop db cstr (10000000 :: Int)

    c_wg_detach_database db
    return ()

 where
   loop db cstr 0 = return ()
   loop db cstr n = do
       re  <- c_wg_create_record db 1
       enc <- c_wg_encode_str db cstr 0
       c_wg_set_field db re 0 enc
       loop db cstr (n - 1)