Fragmento

fragmento is a Go package designed for the fragmentation and assembly of data transmitted over the network. It utilizes a fragmentation mechanism to break large messages into smaller parts that can be sent over UDP or other data transmission methods.

Installation

To install the package, use:

go get github.com/yazmeyaa/fragmento

UDP Request Structure

Field	Size (bytes)	Description
ID	4	Unique identifier for the request
Packed Fields	1	Packed fields
Index	2	Index of the current fragment (0-based)
Total	2	Total number of fragments
Size	2	Size of the payload (data)
Payload	Var.	Payload (data)
Checksum	4	Checksum for verifying data integrity

Packed Fields Description

• 0: Fragmented Flag (1 bit)
• 1-7: RESERVED (7 bits)

Fragmented Flag

The Fragmented Flag indicates whether the packet is a fragment of a larger message. If this flag is set to 1, it signifies that the current packet is part of a fragmented transmission, allowing the receiver to identify and process it correctly within the context of the complete message.

Core Entities

Fragment

The Fragment struct represents a data fragment containing a header, size, payload, and checksum.

Methods

• Serialize() []byte
  Serializes the fragment into a byte slice for transmission over the network.

Header

The Header struct represents the header of a fragment, which includes an identifier, fragmentation flag, fragment index, and total number of fragments.

Methods

• Serialize() []byte
  Serializes the header into a byte slice.

Main Functions

FragmentData(id uint32, data []byte) []Fragment

Function for fragmenting data. Takes an identifier and a byte array, returning a slice of fragments.

FromFragments(frags []Fragment) []byte

Function that assembles data from a slice of fragments and returns the original byte array.

Deserialize(data []byte) (*Fragment, error)

Function to deserialize a byte slice into a fragment object. Returns a pointer to the fragment and an error (if occurred).

Example Usage

package main

import (
    "fmt"
    "github.com/yazmeyaa/fragmento"
)

func main() {
    id := uint32(1)
    data := []byte("Hello, this is a message that needs to be fragmented.")

    // Fragmenting data
    fragments := fragmento.FragmentData(id, data)

    // Serializing fragments
    for _, frag := range fragments {
        serialized := frag.Serialize()
        fmt.Println("Serialized fragment:", serialized)
        
        // Deserializing fragment
        deserializedFrag, err := fragmento.Deserialize(serialized)
        if err != nil {
            fmt.Println("Deserialization error:", err)
            continue
        }
        
        // Checking data
        fmt.Println("Deserialized fragment:", deserializedFrag)
    }

    // Assembling data from fragments
    reconstructedData := fragmento.FromFragments(fragments)
    fmt.Println("Reconstructed data:", string(reconstructedData))
}

License

This project is licensed under the GNU Affero General Public License v3.0.

Contributing

Contributions are welcome! Please feel free to fork the project, submit issues, or open pull requests.