internal/rosa: IR-curable source override

This creates a tarball in-memory for overriding hakurei-source.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/state.go

@@ -1,6 +1,9 @@
 package rosa
 
 import (
+	"archive/tar"
+	"bytes"
+	"compress/gzip"
 	"context"
 	"encoding/json"
 	"errors"
@@ -1173,6 +1176,90 @@ func (s *S) RegisterFS(fsys fs.FS) error {
 	return nil
 }
 
+// SetSource overrides the hakurei-source package with a cached tarball of fsys.
+// The resulting IR is curable on the daemon. Must not be used concurrently with
+// any other method.
+func (s *S) SetSource(fsys fs.FS) error {
+	var buf bytes.Buffer
+	w, err := gzip.NewWriterLevel(&buf, gzip.BestSpeed)
+	if err != nil {
+		return err
+	}
+	tw := tar.NewWriter(w)
+
+	if err = fs.WalkDir(fsys, ".", func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if d.IsDir() && d.Name() == ".git" {
+			return fs.SkipDir
+		}
+
+		var fi fs.FileInfo
+		if fi, err = d.Info(); err != nil {
+			return err
+		}
+
+		var linkname string
+		if fi.Mode()&fs.ModeSymlink != 0 {
+			if linkname, err = fs.ReadLink(fsys, path); err != nil {
+				return err
+			}
+		}
+
+		var h *tar.Header
+		if h, err = tar.FileInfoHeader(fi, linkname); err != nil {
+			return err
+		}
+		h.Name = path
+
+		if err = tw.WriteHeader(h); err != nil {
+			return err
+		}
+
+		if fi.Mode().IsRegular() {
+			var f io.ReadCloser
+			if f, err = fsys.Open(path); err != nil {
+				return err
+			}
+
+			_, err = io.Copy(tw, f)
+			if _err := f.Close(); err == nil {
+				err = _err
+			}
+			if err != nil {
+				return err
+			}
+		}
+		return nil
+	}); err != nil {
+		return err
+	}
+
+	if err = tw.Close(); err != nil {
+		return err
+	} else if err = w.Close(); err != nil {
+		return err
+	}
+
+	const name = "hakurei-source"
+	a := pkg.NewFile("hakurei-src-current.tar.gz", buf.Bytes())
+	s.artifacts.Store(
+		H(name),
+		Artifact(func(t Toolchain) (*Metadata, pkg.Artifact) {
+			return &Metadata{
+				Name:        name,
+				Description: "hakurei source tree (current)",
+				Version:     "1.0.0-CURRENT",
+				Exclude:     true,
+			}, pkg.NewTar(a, pkg.TarGzip)
+		}),
+	)
+	s.DropCaches(s.Arch(), s.Flags())
+	return nil
+}
+
 // SetGentooStage3 sets the Gentoo stage3 tarball url and checksum. It panics
 // if given zero values or if these values have already been set.
 func (s *S) SetGentooStage3(url string, checksum pkg.Checksum) {