/sizeof

SizeOf helps to know size of any data structure in the memory.

Primary LanguageGo

SizeOf

SizeOf helps to know size of any data structure in the memory.

API

  • SizeOf returns total size in bytes that the object allocate in memory.
    func SizeOf(v interface{}) int
  • SizeOfVerbose returns total size in bytes that the object allocate in memory. The second returned value is a detailed report of space usage.
    func SizeOfVerbose(SizeOfVerbose(v interface{}, opts ...Option) (int, SpaceUsageReport)
  • PrintReport prints SpaceUsageReport to the given io.Writer.
    func PrintReport(r *SpaceUsageReport, w io.Writer)
  • MemHumanReadableValue converts bytes to human readable string. Is behaves like the -h option in 'du' command.
    func MemHumanReadableValue(bytes int) string

SizeOfVerbose Options:

  • ExtendedReport includes to the report every object in each slice and map.

SpaceUsageReport

SpaceUsageReport holds detail information of space usage.

type SpaceUsageReport struct { Values map[string]string Children []*SpaceUsageReport }

Possible valuues of the SpaceUsageReport:

Go Type Report's field Description
Everyone ___type Datatype of the object
__object-kind Kind of the object array/map/slice/struct and etc...
__size String with human a readable size value
Array _length Lenght of the array
_count-each-key Shows that size calculation individualy provided for each underlining object
Map _length Lenght of the array
_size-structure Memory for holding size structure of the slice
_count-each-key Shows that size calculation individualy provided for each stored key
_count-each-value Shows that size calculation individualy provided for each stored value
Pointer point-to Type of the object to whitch pointer points to
already-taken Size already taken to account somewhere else
Slice _length Lenght of the slice
_capacity Capacity of the slice
_cap-len:length Difference between capacity and length
_cap-len:size Allocation for that difference
_size-slice-overhead Memory for holding size structure of the slice
String length Length of the string
Struct ____field Field name of the structure

Example

package main

import (
	"fmt"
	"os"

	"github.com/Maxfer4Maxfer/sizeof"
)

type a struct {
	a int
	b string
	c []*a
}

func main() {
	a1 := a{a: 1, b: "one"}
	a2 := &a{a: 2, b: "two"}
	a3 := &a{a: 3, b: "three"}
	a4 := a{a: 4, b: "four"}

	all1 := a{1000, "all", []*a{&a1}}
	all2 := a{1000, "all", []*a{&a1, a2}}
	all3 := a{1000, "all", []*a{&a1, a2, a3}}
	all4 := a{1000, "all", []*a{&a1, a2, a3, &a4}}

	allS := []a{all1, all2, all3, all4}

	all := make(map[string]interface{}, 100)

	all["a-1"] = a1
	all["a-2"] = a2
	all["all-one"] = all1
	all["all-two"] = all2
	all["all-tree"] = all3
	all["all-four"] = all4
	all["all-slice"] = allS

	size, report := sizeof.SizeOfVerbose(all, sizeof.ExtendedReport())

	fmt.Printf("total %d bytes or %s\n", size, sizeof.MemHumanReadableValue(size))

	sizeof.PrintReport(&report, os.Stdout)
}

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