Change API from StateOK/Apply to CheckApply()

This simplifies the API, and reduces code duplication for most
resources. It became obvious when writing the pkg resource, that the two
operations should really be one. Hopefully this will last! Comments
welcome.

file.go

@@ -62,6 +62,20 @@ func (obj *FileRes) GetRes() string {
 	return "File"
 }
 
+func (obj *FileRes) GetPath() string {
+	d := Dirname(obj.Path)
+	b := Basename(obj.Path)
+	if !obj.Validate() || (obj.Dirname == "" && obj.Basename == "") {
+		return obj.Path
+	} else if obj.Dirname == "" {
+		return d + obj.Basename
+	} else if obj.Basename == "" {
+		return obj.Dirname + b
+	} else { // if obj.dirname != "" && obj.basename != "" {
+		return obj.Dirname + obj.Basename
+	}
+}
+
 // validate if the params passed in are valid data
 func (obj *FileRes) Validate() bool {
 	if obj.Dirname != "" {
@@ -79,20 +93,6 @@ func (obj *FileRes) Validate() bool {
 	return true
 }
 
-func (obj *FileRes) GetPath() string {
-	d := Dirname(obj.Path)
-	b := Basename(obj.Path)
-	if !obj.Validate() || (obj.Dirname == "" && obj.Basename == "") {
-		return obj.Path
-	} else if obj.Dirname == "" {
-		return d + obj.Basename
-	} else if obj.Basename == "" {
-		return obj.Dirname + b
-	} else { // if obj.dirname != "" && obj.basename != "" {
-		return obj.Dirname + obj.Basename
-	}
-}
-
 // File watcher for files and directories
 // Modify with caution, probably important to write some test cases first!
 // obj.GetPath(): file or directory
@@ -270,84 +270,29 @@ func (obj *FileRes) HashSHA256fromContent() string {
 	return obj.sha256sum
 }
 
-// FIXME: add the obj.CleanState() calls all over the true returns!
-func (obj *FileRes) StateOK() bool {
-	if obj.isStateOK { // cache the state
-		return true
-	}
-
-	if _, err := os.Stat(obj.GetPath()); os.IsNotExist(err) {
-		// no such file or directory
-		if obj.State == "absent" {
-			return obj.CleanState() // missing file should be missing, phew :)
-		} else {
-			// state invalid, skip expensive checksums
-			return false
-		}
-	}
-
-	// TODO: add file mode check here...
-
-	if PathIsDir(obj.GetPath()) {
-		return obj.StateOKDir()
-	} else {
-		return obj.StateOKFile()
-	}
-}
-
-func (obj *FileRes) StateOKFile() bool {
-	if PathIsDir(obj.GetPath()) {
+func (obj *FileRes) FileHashSHA256Check() (bool, error) {
+	if PathIsDir(obj.GetPath()) { // assert
 		log.Fatal("This should only be called on a File resource.")
 	}
-
 	// run a diff, and return true if needs changing
-
 	hash := sha256.New()
-
 	f, err := os.Open(obj.GetPath())
 	if err != nil {
-		//log.Fatal(err)
-		return false
+		return false, err
 	}
 	defer f.Close()
-
 	if _, err := io.Copy(hash, f); err != nil {
-		//log.Fatal(err)
-		return false
+		return false, err
 	}
-
 	sha256sum := hex.EncodeToString(hash.Sum(nil))
 	//log.Printf("sha256sum: %v", sha256sum)
-
 	if obj.HashSHA256fromContent() == sha256sum {
-		return true
+		return true, nil
 	}
-
-	return false
+	return false, nil
 }
 
-func (obj *FileRes) StateOKDir() bool {
-	if !PathIsDir(obj.GetPath()) {
-		log.Fatal("This should only be called on a Dir resource.")
-	}
-
-	// XXX: not implemented
-	log.Fatal("Not implemented!")
-	return false
-}
-
-func (obj *FileRes) Apply() bool {
-	log.Printf("%v[%v]: Apply", obj.GetRes(), obj.GetName())
-
-	if PathIsDir(obj.GetPath()) {
-		return obj.ApplyDir()
-	} else {
-		return obj.ApplyFile()
-	}
-}
-
-func (obj *FileRes) ApplyFile() bool {
-
+func (obj *FileRes) FileApply() error {
 	if PathIsDir(obj.GetPath()) {
 		log.Fatal("This should only be called on a File resource.")
 	}
@@ -355,37 +300,72 @@ func (obj *FileRes) ApplyFile() bool {
 	if obj.State == "absent" {
 		log.Printf("About to remove: %v", obj.GetPath())
 		err := os.Remove(obj.GetPath())
-		if err != nil {
-			return false
-		}
-		return true
+		return err // either nil or not, for success or failure
 	}
 
-	//log.Println("writing: " + filename)
 	f, err := os.Create(obj.GetPath())
 	if err != nil {
-		log.Println("error:", err)
-		return false
+		return nil
 	}
 	defer f.Close()
 
 	_, err = io.WriteString(f, obj.Content)
 	if err != nil {
-		log.Println("error:", err)
-		return false
+		return err
 	}
 
-	return true
+	return nil // success
 }
 
-func (obj *FileRes) ApplyDir() bool {
-	if !PathIsDir(obj.GetPath()) {
-		log.Fatal("This should only be called on a Dir resource.")
+func (obj *FileRes) CheckApply(apply bool) (stateok bool, err error) {
+	log.Printf("%v[%v]: CheckApply(%t)", obj.GetRes(), obj.GetName(), apply)
+
+	if obj.isStateOK { // cache the state
+		return true, nil
 	}
 
-	// XXX: not implemented
-	log.Fatal("Not implemented!")
-	return true
+	if _, err := os.Stat(obj.GetPath()); os.IsNotExist(err) {
+		// no such file or directory
+		if obj.State == "absent" {
+			// missing file should be missing, phew :)
+			obj.isStateOK = true
+			return true, nil
+		}
+	}
+
+	// FIXME: add file mode check here...
+
+	if PathIsDir(obj.GetPath()) {
+		log.Fatal("Not implemented!") // XXX
+	} else {
+		ok, err := obj.FileHashSHA256Check()
+		if err != nil {
+			return false, err
+		}
+		if ok {
+			obj.isStateOK = true
+			return true, nil
+		}
+		// if no err, but !ok, then we continue on...
+	}
+
+	// state is not okay, no work done, exit, but without error
+	if !apply {
+		return false, nil
+	}
+
+	// apply portion
+	if PathIsDir(obj.GetPath()) {
+		log.Fatal("Not implemented!") // XXX
+	} else {
+		err = obj.FileApply()
+		if err != nil {
+			return false, err
+		}
+	}
+
+	obj.isStateOK = true
+	return false, nil // success
 }
 
 func (obj *FileRes) Compare(res Res) bool {