encoding/gob: oom on doubly linked list #66951
Comments
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Below is the demo code. It cannot work. package main
import (
"encoding/gob"
"fmt"
"log"
"os"
)
type Node struct {
Val int
Prev *Node
Next *Node
}
func main() {
// Creating doubly linked list
head := &Node{Val: 1}
head.Next = &Node{Val: 2, Prev: head}
head.Next.Next = &Node{Val: 3, Prev: head.Next}
// Create and open file to store data
file, err := os.Create("store.gob")
if err != nil {
log.Fatal("create file error:", err)
}
defer file.Close()
// Create encoder and encode structure to file
enc := gob.NewEncoder(file)
if err = enc.Encode(head); err != nil {
log.Fatal("encode error:", err)
}
// Close the file
file.Close()
// Open file to be ready for decoding
file, err = os.Open("store.gob")
if err != nil {
log.Fatal("open file error:", err)
}
defer file.Close()
// Create decoder and decode structure from file
var decodedHead Node
dec := gob.NewDecoder(file)
if err = dec.Decode(&decodedHead); err != nil {
log.Fatal("decode error:", err)
}
// Printing decoded data
for node := &decodedHead; node != nil; node = node.Next {
fmt.Println(node.Val)
}
} |
|
The singly linked list works perfect. package main
import (
"encoding/gob"
"fmt"
"log"
"os"
)
type Node struct {
Val int
Next *Node
}
func main() {
// Creating singly linked list
head := &Node{Val: 1}
head.Next = &Node{Val: 2}
head.Next.Next = &Node{Val: 3}
// Create and open file to store data
file, err := os.Create("store.gob")
if err != nil {
log.Fatal("creation file error:", err)
}
defer file.Close()
// Create encoder and encode structure to file
enc := gob.NewEncoder(file)
if err = enc.Encode(head); err != nil {
log.Fatal("encoding error:", err)
}
// Close the file
file.Close()
// Open file for decoding
file, err = os.Open("store.gob")
if err != nil {
log.Fatal("opening file error:", err)
}
defer file.Close()
// Create decoder and decode structure from file
var decodedHead Node
dec := gob.NewDecoder(file)
if err = dec.Decode(&decodedHead); err != nil {
log.Fatal("decoding error:", err)
}
// Printing the decoded list
for node := &decodedHead; node != nil; node = node.Next {
fmt.Println(node.Val)
}
} |
|
from the package docs
|
|
thanks for your reply. |
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Go version
go version go1.22.2 linux/amd64
Output of
go envin your module/workspace:What did you do?
I use gob.Encode to save a doubly linked list.
This is the struct
What did you see happen?
it will casue oom.
What did you expect to see?
save to file success
The text was updated successfully, but these errors were encountered: