internal/pkg: exclusive artifacts

This alleviates scheduler overhead when curing many artifacts.

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

internal/pkg/file.go

@@ -37,13 +37,16 @@ func NewFile(name string, data []byte) FileArtifact {
 }
 
 // Kind returns the hardcoded [Kind] constant.
-func (a *fileArtifact) Kind() Kind { return KindFile }
+func (*fileArtifact) Kind() Kind { return KindFile }
 
 // Params writes the result of Cure.
 func (a *fileArtifact) Params(ctx *IContext) { ctx.GetHash().Write(*a) }
 
 // Dependencies returns a nil slice.
-func (a *fileArtifact) Dependencies() []Artifact { return nil }
+func (*fileArtifact) Dependencies() []Artifact { return nil }
+
+// IsExclusive returns false: Cure returns a prepopulated buffer.
+func (*fileArtifact) IsExclusive() bool { return false }
 
 // Checksum computes and returns the checksum of caller-supplied data.
 func (a *fileArtifact) Checksum() Checksum {