arduino#1447 - back-end usage scenario

Add `FilesService` impl.

cli/daemon/daemon.go

@@ -35,6 +35,7 @@ import (
  srv_debug "github.com/arduino/arduino-cli/rpc/cc/arduino/cli/debug/v1"
  srv_monitor "github.com/arduino/arduino-cli/rpc/cc/arduino/cli/monitor/v1"
  srv_settings "github.com/arduino/arduino-cli/rpc/cc/arduino/cli/settings/v1"
+ srv_files "github.com/arduino/arduino-cli/rpc/cc/arduino/cli/files/v1"
  "github.com/segmentio/stats/v4"
  "github.com/sirupsen/logrus"
  "github.com/spf13/cobra"
@@ -98,6 +99,9 @@ func runDaemonCommand(cmd *cobra.Command, args []string) {
  // Register the debug session service
  srv_debug.RegisterDebugServiceServer(s, &daemon.DebugService{})
 
+ // Register the files service
+ srv_files.RegisterFilesServiceServer(s, &daemon.FilesService{})
+
  if !daemonize {
  // When parent process ends terminate also the daemon
  go func() {

commands/daemon/files.go

@@ -0,0 +1,41 @@
+// This file is part of arduino-cli.
+//
+// Copyright 2020 ARDUINO SA (http://www.arduino.cc/)
+//
+// This software is released under the GNU General Public License version 3,
+// which covers the main part of arduino-cli.
+// The terms of this license can be found at:
+// https://www.gnu.org/licenses/gpl-3.0.en.html
+//
+// You can be released from the requirements of the above licenses by purchasing
+// a commercial license. Buying such a license is mandatory if you want to
+// modify or otherwise use the software for commercial activities involving the
+// Arduino software without disclosing the source code of your own applications.
+// To purchase a commercial license, send an email to [email protected].
+
+package daemon
+
+import (
+ "context"
+ "os"
+
+ rpc "github.com/arduino/arduino-cli/rpc/cc/arduino/cli/files/v1"
+)
+
+// FilesService implements the `Files` service
+type FilesService struct {
+ rpc.UnimplementedFilesServiceServer
+}
+
+// LoadFile returns a requested file content or an error.
+func (s *FilesService) LoadFile(ctx context.Context, req *rpc.LoadFileRequest) (*rpc.LoadFileResponse, error) {
+ content, err := os.ReadFile(req.Path)
+ if err == nil {
+ return &rpc.LoadFileResponse{
+ Content: content,
+ Type: rpc.ContentType_CONTENT_TYPE_RAW_UNSPECIFIED,
+ }, nil
+ }
+
+ return nil, err
+}