ref: Create a storage interface

This `Storage` interface will define all the interactions with the
storage system. For now I plan to support native file system through
go's standard library and Nextcloud through *webdav*. So this is the
first step in that direction.

2 files changed, 55 insertions, 75 deletions

diff --git a/fileop/fileop.go b/fileop/fileop.go
index d08cb82..1be3f2e 100644
--- a/fileop/fileop.go
+++ b/fileop/fileop.go
@@ -8,7 +8,15 @@ import (
 	"path/filepath"
 )
 
-func WalkFolder(folder string) <-chan string {
+type WalkMode int
+
+const (
+	Folder WalkMode = iota
+	File
+	FileFolder
+)
+
+func WalkFolder(folder string, walkMode WalkMode) <-chan string {
 	c := make(chan string)
 
 	go func(folder string, c chan string) {
@@ -16,7 +24,17 @@ func WalkFolder(folder string) <-chan string {
 			file, _ := os.Open(path)
 			defer file.Close()
 			fileInfo, _ := file.Stat()
-			if !fileInfo.IsDir() {
+
+			switch walkMode {
+			case Folder:
+				if fileInfo.IsDir() {
+					c <- path
+				}
+			case File:
+				if !fileInfo.IsDir() {
+					c <- path
+				}
+			case FileFolder:
 				c <- path
 			}
 			return nil
@@ -28,15 +46,9 @@ func WalkFolder(folder string) <-chan string {
 	return c
 }
 
-func CalculateSHA256(file string) (string, error) {
-	f, err := os.Open(file)
-	if err != nil {
-		return "", err
-	}
-	defer f.Close()
-
+func CalculateSHA256(r io.Reader) (string, error) {
 	h := sha256.New()
-	if _, err := io.Copy(h, f); err != nil {
+	if _, err := io.Copy(h, r); err != nil {
 		return "", err
 	}
 
@@ -64,3 +76,17 @@ func Move() chan<- *MoveCommand {
 
 	return c
 }
+
+func IsEmpty(name string) (bool, error) {
+	f, err := os.Open(name)
+	if err != nil {
+		return false, err
+	}
+	defer f.Close()
+
+	_, err = f.Readdirnames(1)
+	if err == io.EOF {
+		return true, nil
+	}
+	return false, err
+}
diff --git a/fileop/fileop_test.go b/fileop/fileop_test.go
index f2ab864..134090d 100644
--- a/fileop/fileop_test.go
+++ b/fileop/fileop_test.go
@@ -2,57 +2,14 @@ package fileop
 
 import (
 	"fmt"
-	"math/rand"
 	"os"
+	"porg/testutil"
 	"testing"
-	"time"
 )
 
-func init() {
-	rand.Seed(time.Now().UnixNano())
-}
-
-func RandomString(n int) string {
-	var letters = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789")
-	s := make([]rune, n)
-	for i := range s {
-		s[i] = letters[rand.Intn(len(letters))]
-	}
-	return string(s)
-}
-
-func createFolder() (tmp string) {
-	tmp = fmt.Sprintf("/tmp/%s", RandomString(10))
-
-	err := os.Mkdir(tmp, 0755)
-
-	if err != nil {
-		fmt.Println(err.Error())
-	}
-
-	return
-}
-
-func appendEmptyFile(path string) (fullPath string) {
-	fullPath = fmt.Sprintf("%s/%s", path, RandomString(10))
-	os.OpenFile(fullPath, os.O_RDONLY|os.O_CREATE, 0666)
-
-	return
-}
-
-func createEmptyFile(path string) {
-	os.OpenFile(path, os.O_RDONLY|os.O_CREATE, 0666)
-}
-
-func createTmpFile() (fullPath string) {
-	path := createFolder()
-	fullPath = appendEmptyFile(path)
-	return
-}
-
 func TestMove(t *testing.T) {
-	src := createTmpFile()
-	dest := fmt.Sprintf("/tmp/%s", RandomString(10))
+	src := testutil.CreateTmpFile()
+	dest := fmt.Sprintf("/tmp/%s", testutil.RandomString(10))
 
 	c := Move()
 
@@ -65,33 +22,30 @@ func TestMove(t *testing.T) {
 
 }
 
-func TestWalk(t *testing.T) {
-	fileCount := 1000
-	folder := createFolder()
-	files := map[string]struct{}{}
-	walkedFiles := map[string]struct{}{}
+func TestIsEmpty(t *testing.T) {
+	folder := testutil.CreateFolder()
 
-	for i := 0; i < fileCount; i++ {
-		files[appendEmptyFile(folder)] = struct{}{}
-	}
+	empty, err := IsEmpty(folder)
 
-	c := WalkFolder(folder)
-	for file := range c {
-		walkedFiles[file] = struct{}{}
+	if err != nil {
+		t.Fatalf("Error reading the folder %s", err.Error())
 	}
 
-	for k := range files {
-		_, ok := walkedFiles[k]
-		if !ok {
-			t.Errorf("File %s was not walked", k)
-		}
+	if !empty {
+		t.Errorf("Folder is not empty %s", folder)
 	}
+
 }
 
 func TestCalculateSHA256(t *testing.T) {
-	sh256, _ := CalculateSHA256("test_file.txt")
 
-	if sh256 != "027cc886f9b8c866f932ef8b8da9a32f0857ef8e16ec98dd2797021b34623b88" {
-		t.Errorf("Wrong sh256 hash, given %s", sh256)
+	if f, err := os.Open("test_file.txt"); err != nil {
+		t.Error(err)
+	} else {
+		sh256, _ := CalculateSHA256(f)
+		if sh256 != "027cc886f9b8c866f932ef8b8da9a32f0857ef8e16ec98dd2797021b34623b88" {
+			t.Errorf("Wrong sh256 hash, given %s", sh256)
+		}
 	}
+
 }