Initial Store implementation

.gitignore

@@ -11,5 +11,4 @@
 # Output of the go coverage tool, specifically when used with LiteIDE
 *.out
 
-# Dependency directories (remove the comment below to include it)
+foo/
-# vendor/

go.mod

@@ -0,0 +1,5 @@
+module github.com/firestuff/checky
+
+go 1.16
+
+require github.com/google/uuid v1.3.0

go.sum

@@ -0,0 +1,2 @@
+github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
+github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=

main.go

@@ -0,0 +1,24 @@
+package main
+
+import "fmt"
+
+import "github.com/google/uuid"
+
+func main() {
+  store := NewStore("foo")
+
+  out := &Template{
+    Id: uuid.NewString(),
+    Test: "round trip",
+  }
+
+  store.Write(out)
+
+  in := &Template{
+    Id: out.Id,
+  }
+
+  store.Read(in)
+
+  fmt.Printf("%+v\n", in)
+}

store.go

@@ -0,0 +1,79 @@
+package main
+
+import "encoding/hex"
+import "encoding/json"
+import "fmt"
+import "os"
+import "path/filepath"
+
+type Storable interface {
+  GetType() string
+  GetId() string
+}
+
+type Store struct {
+  root string
+}
+
+func NewStore(root string) *Store {
+  return &Store{
+    root: root,
+  }
+}
+
+func (s *Store) Write(obj Storable) error {
+  dir := filepath.Join(s.root, obj.GetType())
+  filename := hex.EncodeToString([]byte(obj.GetId()))
+
+  err := os.MkdirAll(dir, 0700)
+  if err != nil {
+    return err
+  }
+
+  tmp, err := os.CreateTemp(dir, fmt.Sprintf("%s.*", filename))
+  if err != nil {
+    return err
+  }
+  defer tmp.Close()
+
+  enc := json.NewEncoder(tmp)
+  enc.SetEscapeHTML(false)
+
+  err = enc.Encode(obj)
+  if err != nil {
+    return err
+  }
+
+  err = tmp.Close()
+  if err != nil {
+    return err
+  }
+
+  err = os.Rename(tmp.Name(), filepath.Join(dir, filename))
+  if err != nil {
+    return err
+  }
+
+  return nil
+}
+
+func (s *Store) Read(obj Storable) error {
+  dir := filepath.Join(s.root, obj.GetType())
+  filename := hex.EncodeToString([]byte(obj.GetId()))
+
+  fh, err := os.Open(filepath.Join(dir, filename))
+  if err != nil {
+    return err
+  }
+  defer fh.Close()
+
+  dec := json.NewDecoder(fh)
+  dec.DisallowUnknownFields()
+
+  err = dec.Decode(obj)
+  if err != nil {
+    return err
+  }
+
+  return nil
+}

template.go

@@ -0,0 +1,14 @@
+package main
+
+type Template struct {
+  Id string
+  Test string
+}
+
+func (t *Template) GetType() string {
+  return "template"
+}
+
+func (t *Template) GetId() string {
+  return t.Id
+}