63 lines
1.3 KiB
Go
63 lines
1.3 KiB
Go
// For more tutorials: https://blog.learngoprogramming.com
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//
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// Copyright © 2018 Inanc Gumus
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// Learn Go Programming Course
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// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
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//
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package main
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import (
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"fmt"
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"runtime"
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"runtime/debug"
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"unsafe"
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)
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const size = 1e7
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func main() {
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// stops the gc: prevents cleaning up the memory
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debug.SetGCPercent(-1)
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report("initial memory usage")
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var array [size]int
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report("after declaring an array")
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array2 := array
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report("after copying the array")
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passArray(array)
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slice1 := array[:]
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slice2 := array[1e3:]
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slice3 := array[1e3:1e4]
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report("after slicings")
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passSlice(slice3)
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fmt.Println()
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fmt.Printf("Array's size : %d bytes.\n", unsafe.Sizeof(array))
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fmt.Printf("Array2's size: %d bytes.\n", unsafe.Sizeof(array2))
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fmt.Printf("Slice1's size: %d bytes.\n", unsafe.Sizeof(slice1))
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fmt.Printf("Slice2's size: %d bytes.\n", unsafe.Sizeof(slice2))
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fmt.Printf("Slice3's size: %d bytes.\n", unsafe.Sizeof(slice3))
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}
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func passArray(items [size]int) {
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items[0] = 100
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report("inside passArray")
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}
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func passSlice(items []int) {
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report("inside passSlice")
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}
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func report(msg string) {
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var m runtime.MemStats
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runtime.ReadMemStats(&m)
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fmt.Printf("[%s]\n", msg)
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fmt.Printf("\t> Memory Usage: %v KB\n", m.Alloc/1024)
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}
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