app.go

/*

A trivial application to illustrate how the dfslib library can be used
from an application in assignment 2 for UBC CS 416 2017W2.

Usage:
go run app.go
*/

package main

// Expects dfslib.go to be in the ./dfslib/ dir, relative to
// this app.go file
import "./dfslib"

import "fmt"
import "os"

func main() {
	serverAddr := "0.0.0.0:8080"
	localIP := "0.0.0.0"
	localPath := "/tmp/dfs-dev/"

	// Connect to DFS.
	_, err := dfslib.MountDFS(serverAddr, localIP, localPath)
	if checkError(err) != nil {
		fmt.Println(err)
		return
	}

	// // Close the DFS on exit.
	// // Defers are really cool, check out: https://blog.golang.org/defer-panic-and-recover
	// defer dfs.UMountDFS()

	// // Check if hello.txt file exists in the global DFS.
	// exists, err := dfs.GlobalFileExists("helloworld")
	// if checkError(err) != nil {
	// 	return
	// }

	// if exists {
	// 	fmt.Println("File already exists, mission accomplished")
	// 	return
	// }

	// // Open the file (and create it if it does not exist) for writing.
	// f, err := dfs.Open("helloworld", dfslib.WRITE)
	// if checkError(err) != nil {
	// 	return
	// }

	// // Close the file on exit.
	// defer f.Close()

	// // Create a chunk with a string message.
	// var chunk dfslib.Chunk
	// const str = "Hello friends!"
	// copy(chunk[:], str)

	// // Write the 0th chunk of the file.
	// err = f.Write(0, &chunk)
	// if checkError(err) != nil {
	// 	return
	// }

	// // Read the 0th chunk of the file.
	// err = f.Read(0, &chunk)
	// checkError(err)
}

// If error is non-nil, print it out and return it.
func checkError(err error) error {
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error ", err.Error())
		return err
	}
	return nil
}