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.

3 files changed, 99 insertions, 0 deletions

diff --git a/storage/storage.go b/storage/storage.go
new file mode 100644
index 0000000..b788efb
--- /dev/null
+++ b/storage/storage.go
@@ -0,0 +1,30 @@
+package storage
+
+import (
+	"crypto/sha256"
+	"fmt"
+	"io"
+)
+
+type WalkMode int
+
+const (
+	Folder WalkMode = iota
+	File
+	FileFolder
+)
+
+type Storage interface {
+	Walk(path string, walkMode WalkMode) <-chan string
+	Get(path string) (io.Reader, error)
+}
+
+func CalculateSHA256(r io.Reader) (string, error) {
+	h := sha256.New()
+	if _, err := io.Copy(h, r); err != nil {
+		return "", err
+	}
+
+	return fmt.Sprintf("%x", h.Sum(nil)), nil
+
+}
diff --git a/storage/storage_fs.go b/storage/storage_fs.go
new file mode 100644
index 0000000..35ce58b
--- /dev/null
+++ b/storage/storage_fs.go
@@ -0,0 +1,40 @@
+package storage
+
+import (
+	"os"
+	"path/filepath"
+)
+
+type FileSystem struct {
+	root string
+}
+
+func WalkFolder(folder string, walkMode WalkMode) <-chan string {
+	c := make(chan string)
+
+	go func(folder string, c chan string) {
+		filepath.Walk(folder, func(path string, info os.FileInfo, err error) error {
+			file, _ := os.Open(path)
+			defer file.Close()
+			fileInfo, _ := file.Stat()
+
+			switch walkMode {
+			case Folder:
+				if fileInfo.IsDir() {
+					c <- path
+				}
+			case File:
+				if !fileInfo.IsDir() {
+					c <- path
+				}
+			case FileFolder:
+				c <- path
+			}
+			return nil
+		})
+		close(c)
+
+	}(folder, c)
+
+	return c
+}
diff --git a/storage/storage_fs_test.go b/storage/storage_fs_test.go
new file mode 100644
index 0000000..b746c7e
--- /dev/null
+++ b/storage/storage_fs_test.go
@@ -0,0 +1,29 @@
+package storage
+
+import (
+	"porg/testutil"
+	"testing"
+)
+
+func TestWalk(t *testing.T) {
+	fileCount := 1000
+	folder := testutil.CreateFolder()
+	files := map[string]struct{}{}
+	walkedFiles := map[string]struct{}{}
+
+	for i := 0; i < fileCount; i++ {
+		files[testutil.AppendEmptyFile(folder)] = struct{}{}
+	}
+
+	c := WalkFolder(folder, File)
+	for file := range c {
+		walkedFiles[file] = struct{}{}
+	}
+
+	for k := range files {
+		_, ok := walkedFiles[k]
+		if !ok {
+			t.Errorf("File %s was not walked", k)
+		}
+	}
+}