1 files changed, 30 insertions, 23 deletions

diff --git a/skate/cmd/skate-conv/main.go b/skate/cmd/skate-conv/main.go
index 647472e..34e79a3 100644
--- a/skate/cmd/skate-conv/main.go
+++ b/skate/cmd/skate-conv/main.go
@@ -21,10 +21,9 @@ import (
 var (
 	numWorkers = flag.Int("w", runtime.NumCPU(), "number of workers")
 	batchSize  = flag.Int("b", 100000, "batch size")
-	fromFormat = flag.String("f", "ref", "import schema")
+	fromFormat = flag.String("f", "ref", "import schema: ref, rg, ol")
 
-	bytesNewline = []byte("\n")
-	f            func([]byte) ([]byte, error)
+	f func([]byte) ([]byte, error) // our converter function
 )
 
 func main() {
@@ -36,6 +35,8 @@ func main() {
 		f = rgSitemapToRelease
 	case "ol":
 		f = openLibraryToRelease
+	default:
+		log.Fatal("unsupported input schema: %v", *fromFormat)
 	}
 	pp := parallel.NewProcessor(os.Stdin, os.Stdout, f)
 	pp.NumWorkers = *numWorkers
@@ -45,55 +46,61 @@ func main() {
 	}
 }
 
-// refToRelease converts a ref document to a release.
+// refToRelease converts a ref document to a release. The standard conversion
+// plus some extra fields.
 func refToRelease(p []byte) ([]byte, error) {
-	var ref skate.Ref
-	if err := json.Unmarshal(p, &ref); err != nil {
+	var (
+		ref     skate.Ref
+		release *skate.Release
+		err     error
+	)
+	if err = json.Unmarshal(p, &ref); err != nil {
 		return nil, err
 	}
-	release, err := skate.RefToRelease(&ref)
-	if err != nil {
+	if release, err = skate.RefToRelease(&ref); err != nil {
 		return nil, err
 	}
 	release.Extra.Skate.Status = "ref" // means: converted from ref
 	release.Extra.Skate.Ref.Index = ref.Index
 	release.Extra.Skate.Ref.Key = ref.Key
-	b, err := json.Marshal(release)
-	b = append(b, bytesNewline...)
-	return b, err
+	return skate.JsonMarshalNewline(release)
 }
 
+// rgSitemapToRelease converts a simple sitemap to a release entity, e.g. from
+// https://archive.org/download/rg_sitemap_2021_02_23/rg_sitemap_2021_02_23.ndj.zst.
 func rgSitemapToRelease(p []byte) ([]byte, error) {
 	var (
 		s       skate.Sitemap
 		release skate.Release
+		err     error
 	)
-	if err := json.Unmarshal(p, &s); err != nil {
+	if err = json.Unmarshal(p, &s); err != nil {
 		return nil, err
 	}
 	release.Title = s.Title
 	if len(s.URL) > 41 {
-		// XXX: A pseudo ident, maybe irritating.
+		// A pseudo ident, maybe irritating; we want the "321885388".
+		// https://www.researchgate.net/publication/321885388_We_came_here_on_dif
 		release.Ident = strings.Split(s.URL[41:], "_")[0]
 	}
 	release.Extra.Skate.Status = "rg"
 	release.Extra.Skate.ResearchGate.URL = s.URL
-	b, err := json.Marshal(release)
-	b = append(b, bytesNewline...)
-	return b, err
+	return skate.JsonMarshalNewline(release)
 }
 
+// openLibraryToRelease converts an Open Library work item to a release.
 func openLibraryToRelease(p []byte) ([]byte, error) {
-	var w skate.OpenLibraryWork
-	if err := json.Unmarshal(p, &w); err != nil {
+	var (
+		w       skate.OpenLibraryWork
+		release *skate.Release
+		err     error
+	)
+	if err = json.Unmarshal(p, &w); err != nil {
 		return nil, err
 	}
-	release, err := skate.OpenLibraryToRelease(&w)
-	if err != nil {
+	if release, err = skate.OpenLibraryToRelease(&w); err != nil {
 		return nil, err
 	}
 	release.Extra.Skate.Status = "ol"
-	b, err := json.Marshal(release)
-	b = append(b, bytesNewline...)
-	return b, err
+	return skate.JsonMarshalNewline(release)
 }