Write model to temporary directory (#2)

README.md

@@ -31,6 +31,15 @@ go get github.com/robherley/guesslang-go
 
 See example usage in [`examples/main.go`](/example/main.go)
 
+## Caveats
+
+To work around some of the limitations of the Go TensorFlow bindings (and the wrapper library)[^1], the [SavedModel](https://www.tensorflow.org/guide/saved_model) is embeded in the binary and
+when a [`Guesser`](https://pkg.go.dev/github.com/robherley/guesslang-go/pkg/guesser#Guesser) is initialized, it temporarily writes the model to a directory (and removes it after).
+
+So, in order to use this package, you must at least have a writeable temporary directory that aligns with Go's [`os.TempDir()`](https://pkg.go.dev/os@go1.20.3#TempDir).
+
+[^1]: https://github.com/galeone/tfgo/issues/44#issuecomment-841806254
+
 ## Acknowledgements
 
 Powered by:

pkg/guesser/guesser.go

@@ -19,7 +19,7 @@ type Guesser struct {
 	model *tg.Model
 }
 
-// New initializes a guesslang model
+// New initializes a guesslang model. It will write the TensorFlow SavedModel temporarily to disk, then load it.
 func New() (g *Guesser, err error) {
 	defer func() {
 		// unfortunately, the tfgo library panics instead of returning errors
@@ -28,9 +28,14 @@ func New() (g *Guesser, err error) {
 		}
 	}()
 
-	return &Guesser{
-		model: tg.LoadModel(hackyPathToModel(), []string{"serve"}, nil),
-	}, nil
+	modelPath, err := writeModelToTempDir()
+	if err != nil {
+		return nil, err
+	}
+	defer os.RemoveAll(modelPath)
+
+	model := tg.LoadModel(modelPath, []string{"serve"}, nil)
+	return &Guesser{model}, nil
 }
 
 // Guess executes the guesslang model on a code snippet, providing sorted confidences for all of the supported languages

pkg/guesser/model.go

@@ -0,0 +1,68 @@
+package guesser
+
+import (
+	"embed"
+	"io"
+	"os"
+	"path/filepath"
+)
+
+var (
+	//go:embed model/*
+	savedModel embed.FS
+)
+
+// as far as I know, there is no way to load a SavedModel/graph (with variables) from memory with the go tf library
+// https://github.com/galeone/tfgo/issues/44#issuecomment-841806254
+func writeModelToTempDir() (string, error) {
+	modelPath, err := os.MkdirTemp("", "guesslang-go")
+	if err != nil {
+		return "", err
+	}
+
+	savedModelFile, err := savedModel.Open("model/saved_model.pb")
+	if err != nil {
+		return "", err
+	}
+	defer savedModelFile.Close()
+
+	savedModelFileDisk, err := os.Create(modelPath + "/saved_model.pb")
+	if err != nil {
+		return "", err
+	}
+	defer savedModelFileDisk.Close()
+
+	if _, err := io.Copy(savedModelFileDisk, savedModelFile); err != nil {
+		return "", err
+	}
+
+	err = os.MkdirAll(filepath.Join(modelPath, "variables"), 0755)
+	if err != nil {
+		return "", err
+	}
+
+	variablesFiles, err := savedModel.ReadDir("model/variables")
+	if err != nil {
+		return "", err
+	}
+
+	for _, file := range variablesFiles {
+		variablesFile, err := savedModel.Open("model/variables/" + file.Name())
+		if err != nil {
+			return "", err
+		}
+		defer variablesFile.Close()
+
+		variablesFileDisk, err := os.Create(filepath.Join(modelPath, "variables", file.Name()))
+		if err != nil {
+			return "", err
+		}
+		defer variablesFileDisk.Close()
+
+		if _, err := io.Copy(variablesFileDisk, variablesFile); err != nil {
+			return "", err
+		}
+	}
+
+	return modelPath, nil
+}

script/install-libtensorflow

@@ -11,6 +11,14 @@ if [ "$(go env GOARCH)" != "amd64" ]; then
   exit 1
 fi
 
+function maybe_sudo() {
+  if [ "$(id -u)" -ne 0 ]; then
+    sudo "$@"
+  else
+    "$@"
+  fi
+}
+
 OS=$(go env GOOS)
 
 case "$OS" in
@@ -21,8 +29,8 @@ case "$OS" in
     TENSORFLOW_VERSION=2.11.0
     ARCHIVE_PATH=$(mktemp -d)/tensorflow.tar.gz
     curl -o "$ARCHIVE_PATH" "https://storage.googleapis.com/tensorflow/libtensorflow/libtensorflow-cpu-${OS}-x86_64-${TENSORFLOW_VERSION}.tar.gz"
-    sudo tar -xzf "$ARCHIVE_PATH" -C /usr/local
-    sudo ldconfig /usr/local/lib
+    maybe_sudo tar -xzf "$ARCHIVE_PATH" -C /usr/local
+    maybe_sudo ldconfig /usr/local/lib
     rm -rf "$ARCHIVE_PATH"
     ;;
   *)