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@SteveBate
Created October 2, 2015 14:32
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Example of converting a struct to a byte slice, compressing with gzip, and saving to file followed by the reverse process back to a struct
package main
import (
"bytes"
"compress/gzip"
"encoding/gob"
"fmt"
"io/ioutil"
"log"
"os"
)
type Person struct {
Name string
Address Address
}
type Address struct {
House int
Street1 string
Town string
PostCode PostCode
}
type PostCode struct {
Value string
}
func EncodeToBytes(p interface{}) []byte {
buf := bytes.Buffer{}
enc := gob.NewEncoder(&buf)
err := enc.Encode(p)
if err != nil {
log.Fatal(err)
}
fmt.Println("uncompressed size (bytes): ", len(buf.Bytes()))
return buf.Bytes()
}
func Compress(s []byte) []byte {
zipbuf := bytes.Buffer{}
zipped := gzip.NewWriter(&zipbuf)
zipped.Write(s)
zipped.Close()
fmt.Println("compressed size (bytes): ", len(zipbuf.Bytes()))
return zipbuf.Bytes()
}
func Decompress(s []byte) []byte {
rdr, _ := gzip.NewReader(bytes.NewReader(s))
data, err := ioutil.ReadAll(rdr)
if err != nil {
log.Fatal(err)
}
rdr.Close()
fmt.Println("uncompressed size (bytes): ", len(data))
return data
}
func DecodeToPerson(s []byte) Person {
p := Person{}
dec := gob.NewDecoder(bytes.NewReader(s))
err := dec.Decode(&p)
if err != nil {
log.Fatal(err)
}
return p
}
func WriteToFile(s []byte, file string) {
f, err := os.Create(file)
if err != nil {
log.Fatal(err)
}
f.Write(s)
}
func ReadFromFile(path string) []byte {
f, err := os.Open(path)
if err != nil {
log.Fatal(err)
}
data, err := ioutil.ReadAll(f)
if err != nil {
log.Fatal(err)
}
return data
}
func main() {
p := Person{
Name: "Joe Bloggs",
Address: Address{
House: 1,
Street1: "The Lane",
Town: "Blackburn",
PostCode: PostCode{
Value: "BB2 5LB",
},
},
}
dataOut := EncodeToBytes(p)
dataOut = Compress(dataOut)
WriteToFile(dataOut, "person.dat")
dataIn := ReadFromFile("person.dat")
dataIn = Decompress(dataIn)
p2 := DecodeToPerson(dataIn)
fmt.Println(p2)
}
@aLucaz
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aLucaz commented Nov 18, 2022

nice

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