Simple C String allocations manager for Go.

calloc.go

package yourpackage

/*
#include <stdlib.h>
*/
import "C"
import "unsafe"

// Calloc handles alloc/dealloc of C data
type Calloc struct {
	pool []unsafe.Pointer
}

// NewCalloc creates a new allocator
func NewCalloc() Calloc {
	return Calloc{}
}

// String creates a new C string and retains a reference to it
func (c Calloc) String(in string) *C.char {
	result := C.CString(in)
	c.pool = append(c.pool, unsafe.Pointer(result))
	return result
}

// Free frees all allocated C memory
func (c Calloc) Free() {
	for _, str := range c.pool {
		C.free(str)
	}
	c.pool = []unsafe.Pointer{}
}

calloc

A simple, dependency free wrapper for managing your C string allocations in Go.

Usage

1. Create a new allocator: c := NewCalloc()
2. Defer the free method: defer c.Free()
3. Start creating C strings: myCString := c.String("I am a C string")

Why?

It's a common pattern when using CGO to allocate C strings, use them in a CGO call then deallocate them once the call is complete. This method not only cleans up your code (only 1 defer) but ensures that all allocated memory gets freed.

NOTE: This isn't thread safe as it is not intended to be shared between threads. It is better to create new allocators where needed.

Why isn't this a package?!?

Try it and you'll C why ;-)