The C wrapper

wrapper.c (text/plain), 606 bytes, created by Christopher Head on 2010-08-06 00:42:21 UTC

#include <caml/alloc.h>
#include <caml/memory.h>
#include <caml/mlvalues.h>
#include <string.h>
#include <zlib.h>

CAMLprim value caml_wrapper_compress(value input) {
	CAMLparam1(input);
	CAMLlocal1(result);
	unsigned long input_length = caml_string_length(input);
	unsigned long bound = compressBound(input_length);
	unsigned char buffer[bound];
	unsigned long output_length = sizeof(buffer);
	compress(buffer, &output_length, (const unsigned char *) String_val(input), input_length);
	result = caml_alloc_string(output_length);
	memcpy(String_val(result), buffer, output_length);
	CAMLreturn(result);
}