streamonkey/size

The size of variable at runtime

size - calculates variable's memory consumption at runtime

Part of the Transflow Project

Sometimes you may need a tool to measure the size of object in your Go program at runtime. This package makes an attempt to do so. Package based on binary.Size() from Go standard library.

Features:

• supports non-fixed size variables and struct fields: struct, int, slice, string, map;
• supports complex types including structs with non-fixed size fields;
• supports all basic types (numbers, bool);
• supports chan and interface;
• supports pointers;
• implements infinite recursion detection (i.e. pointer inside struct field references to parent struct).

Usage example

package main

import (
	"fmt"

	// Use latest tag.
	"github.com/DmitriyVTitov/size"
)

func main() {
	a := struct {
		a int
		b string
		c bool
		d int32
		e []byte
		f [3]int64
	}{
		a: 10,                    // 8 bytes
		b: "Text",                // 16 (string itself) + 4 = 20 bytes
		c: true,                  // 1 byte
		d: 25,                    // 4 bytes
		e: []byte{'c', 'd', 'e'}, // 24 (slice itself) + 3 = 27 bytes
		f: [3]int64{1, 2, 3},     // 3 * 8 = 24 bytes
	} // 84 + 3 (padding) = 87 bytes

	fmt.Println(size.Of(a))
}

// Output: 87