Compute the source fingerprint with mesh-sdk's one function (issue 1214)

internal/builder/source.go

@@ -10,6 +10,7 @@ import (
 	"sort"
 	"strings"
 
+	"git.novox.be/novox/mesh-sdk/go/delivery"
 	"github.com/novox/mesh-controller/internal/catalogue"
 )
 
@@ -36,7 +37,7 @@ import (
 // (novox/hq ADR 0097 refuses the unpinned bases; what a RUN step downloads is not seen here).
 
 // sourcePrefix names the fingerprint's form, so a later form is never compared equal to this one.
-const sourcePrefix = "src1:"
+const sourcePrefix = delivery.SourcePrefix
 
 // sourceInputs collects what one build was made from.
 type sourceInputs struct {
@@ -262,40 +263,33 @@ func (s *sourceInputs) notPinned(why string) {
 	}
 }
 
+// sourceFingerprint is the one function the controller's builder and the indexer both call (novox/hq ADR 0437 §5);
+// a variable only so a test can see it called.
+var sourceFingerprint = delivery.SourceFingerprint
+
+// inputs are what the build's fingerprint is of, as the SDK names them.
+func (s *sourceInputs) inputs() delivery.SourceInputs {
+	if s == nil {
+		return delivery.SourceInputs{}
+	}
+	return delivery.SourceInputs{
+		Module: s.module, Tree: s.tree, Bases: s.bases,
+		Contexts: s.contexts, Toolchains: s.toolchains, Unpinned: s.unpinned,
+	}
+}
+
 // fingerprint is the build's source fingerprint, or empty when the source does not pin the build.
 func (s *sourceInputs) fingerprint() string {
-	if s == nil || s.unpinned != "" || s.tree == "" {
+	if s == nil {
 		return ""
 	}
-	var lines []string
-	lines = append(lines, "module "+s.module, "tree "+s.tree)
-	bases := map[string]bool{}
-	for _, b := range s.bases {
-		bases[referenceDigest(b)] = true
-	}
-	for b := range bases {
-		lines = append(lines, "base "+b)
-	}
-	for a, t := range s.contexts {
-		lines = append(lines, "context "+a+" "+t)
-	}
-	for a, t := range s.toolchains {
-		lines = append(lines, "toolchain "+a+" "+t)
-	}
-	// The module and its tree first, the rest in a fixed order.
-	sort.Strings(lines[2:])
-	sum := sha256.Sum256([]byte(strings.Join(lines, "\n")))
-	return sourcePrefix + hex.EncodeToString(sum[:])
+	fp, _ := sourceFingerprint(s.inputs())
+	return fp
 }
 
 // referenceDigest is a reference's digest — `sha256:…` — so the registry address it was copied into does not
 // enter the fingerprint; the reference itself when it carries none.
-func referenceDigest(reference string) string {
-	if _, digest, pinned := strings.Cut(reference, "@"); pinned && digest != "" {
-		return digest
-	}
-	return reference
-}
+func referenceDigest(reference string) string { return delivery.ReferenceDigest(reference) }
 
 // gitTree is the git tree of a directory of a clone at its checked-out commit: the whole tree for an
 // empty path.