Implement resource loading feature

blefs/error.go

@@ -13,6 +13,7 @@ var (
 	ErrOffsetChanged = errors.New("offset has already been changed")
 	ErrReadOpen      = errors.New("only one file can be opened for reading at a time")
 	ErrWriteOpen     = errors.New("only one file can be opened for writing at a time")
+	ErrNoRemoveRoot  = errors.New("refusing to remove root directory")
 )
 
 // FSError represents an error returned by BLE FS

blefs/iofs.go

@@ -12,4 +12,4 @@ func (iofs goFS) Open(path string) (fs.File, error) {
 
 func (blefs *FS) GoFS() fs.FS {
 	return goFS{blefs}
-}
+}

go.sum

@@ -15,6 +15,8 @@ github.com/konsorten/go-windows-terminal-sequences v1.0.3 h1:CE8S1cTafDpPvMhIxNJ
 github.com/konsorten/go-windows-terminal-sequences v1.0.3/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/muka/go-bluetooth v0.0.0-20220819140550-1d8857e3b268 h1:kOnq7TfaAO2Vc/MHxPqFIXe00y1qBxJAvhctXdko6vo=
+github.com/muka/go-bluetooth v0.0.0-20220819140550-1d8857e3b268/go.mod h1:dMCjicU6vRBk34dqOmIZm0aod6gUwZXOXzBROqGous0=
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
 github.com/paypal/gatt v0.0.0-20151011220935-4ae819d591cf/go.mod h1:+AwQL2mK3Pd3S+TUwg0tYQjid0q1txyNUJuuSmz8Kdk=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=

resources.go

@@ -0,0 +1,180 @@
+package infinitime
+
+import (
+	"archive/zip"
+	"encoding/json"
+	"io"
+	"os"
+	"path/filepath"
+
+	"go.arsenm.dev/infinitime/blefs"
+)
+
+// ResourceOperation represents an operation performed during
+// resource loading
+type ResourceOperation uint8
+
+const (
+	// ResourceOperationUpload represents the upload phase
+	// of resource loading
+	ResourceOperationUpload = iota
+	// ResourceOperationRemoveObsolete represents the obsolete
+	// file removal phase of resource loading
+	ResourceOperationRemoveObsolete
+)
+
+// ResourceManifest is the structure of the resource manifest file
+type ResourceManifest struct {
+	Resources []Resource         `json:"resources"`
+	Obsolete  []ObsoleteResource `json:"obsolete_files"`
+}
+
+// Resource represents a resource entry in the manifest
+type Resource struct {
+	Name string `json:"filename"`
+	Path string `json:"path"`
+}
+
+// ObsoleteResource represents an obsolete file entry in the manifest
+type ObsoleteResource struct {
+	Path  string `json:"path"`
+	Since string `json:"since"`
+}
+
+// ResourceLoadProgress contains information on the progress of
+// a resource load
+type ResourceLoadProgress struct {
+	Operation ResourceOperation
+	Name      string
+	Total     int64
+	Sent      int64
+	Err       error
+}
+
+// LoadResources accepts a resources zip file and a BLE FS.
+// It loads the resources from the zip onto the FS.
+func LoadResources(file *os.File, fs *blefs.FS) (<-chan ResourceLoadProgress, error) {
+	out := make(chan ResourceLoadProgress, 10)
+
+	fi, err := file.Stat()
+	if err != nil {
+		return nil, err
+	}
+
+	r, err := zip.NewReader(file, fi.Size())
+	if err != nil {
+		return nil, err
+	}
+
+	m, err := r.Open("resources.json")
+	if err != nil {
+		return nil, err
+	}
+
+	var manifest ResourceManifest
+	err = json.NewDecoder(m).Decode(&manifest)
+	if err != nil {
+		return nil, err
+	}
+
+	go func() {
+		defer close(out)
+
+		for _, file := range manifest.Obsolete {
+			name := filepath.Base(file.Path)
+
+			err := fs.RemoveAll(file.Path)
+			if err != nil {
+				out <- ResourceLoadProgress{
+					Name:      name,
+					Operation: ResourceOperationRemoveObsolete,
+					Err:       err,
+				}
+				return
+			}
+
+			out <- ResourceLoadProgress{
+				Name:      name,
+				Operation: ResourceOperationRemoveObsolete,
+			}
+		}
+
+		for _, file := range manifest.Resources {
+			src, err := r.Open(file.Name)
+			if err != nil {
+				out <- ResourceLoadProgress{
+					Name:      file.Name,
+					Operation: ResourceOperationUpload,
+					Err:       err,
+				}
+				return
+			}
+
+			srcFi, err := src.Stat()
+			if err != nil {
+				out <- ResourceLoadProgress{
+					Name:      file.Name,
+					Operation: ResourceOperationUpload,
+					Total:     srcFi.Size(),
+					Err:       err,
+				}
+				return
+			}
+
+			err = fs.MkdirAll(filepath.Dir(file.Path))
+			if err != nil {
+				out <- ResourceLoadProgress{
+					Name:      file.Name,
+					Operation: ResourceOperationUpload,
+					Total:     srcFi.Size(),
+					Err:       err,
+				}
+				return
+			}
+
+			dst, err := fs.Create(file.Path, uint32(srcFi.Size()))
+			if err != nil {
+				out <- ResourceLoadProgress{
+					Name:      file.Name,
+					Operation: ResourceOperationUpload,
+					Total:     srcFi.Size(),
+					Err:       err,
+				}
+				return
+			}
+
+			progCh := dst.Progress()
+			go func() {
+				for sent := range progCh {
+					out <- ResourceLoadProgress{
+						Name:      file.Name,
+						Operation: ResourceOperationUpload,
+						Total:     srcFi.Size(),
+						Sent:      int64(sent),
+					}
+
+					if sent == uint32(srcFi.Size()) {
+						return
+					}
+				}
+			}()
+
+			n, err := io.Copy(dst, src)
+			if err != nil {
+				out <- ResourceLoadProgress{
+					Name:      file.Name,
+					Operation: ResourceOperationUpload,
+					Total:     srcFi.Size(),
+					Sent:      n,
+					Err:       err,
+				}
+				return
+			}
+
+			src.Close()
+			dst.Close()
+		}
+	}()
+
+	return out, nil
+}