How can I wrap zlib in golang?
I tried to fix the slowest zip implementation of golang by calling c zlib from golang using cgo
but i get the error
error: "deflateInit" uneclared (use in this function first)
deflateInit is defined in zlib.h
Am I missing something? thanks for any hints.
package main
/*
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include "zlib.h"
*/
import "C"
import (
"fmt"
)
func main() {
fmt.Println("hmmm....")
fmt.Println(int(C.random()))
var strm C.struct_z_stream
fmt.Println(strm)
ret := C.deflateInit(&strm, 5) // trouble here
}
source to share
Here is a fixed version of your code. Note #cgo LDFLAGS: -lz
for linking with the zlib library and with a little C function myDeflateInit
which is linked to being deflateInit
a macro, not a function. Notice also the change in definition strm
.
C is pretty annoying to deal with Go unfortunately - I couldn't think of a better way than a little C shim function.
package main
/*
#cgo LDFLAGS: -lz
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include "zlib.h"
int myDeflateInit(z_streamp s, int n) {
return deflateInit(s, n);
}
*/
import "C"
import (
"fmt"
)
func main() {
fmt.Println("hmmm....")
fmt.Println(int(C.random()))
var strm C.z_stream
fmt.Println(strm)
ret := C.myDeflateInit(&strm, 5)
fmt.Println(ret)
}
source to share