internal/rosa: represent runtime dependencies

This also resolves indirect dependencies, reducing noise.

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

internal/rosa/rosa.go

@@ -8,6 +8,7 @@ import (
 	"slices"
 	"strconv"
 	"strings"
+	"sync"
 
 	"hakurei.app/container/fhs"
 	"hakurei.app/internal/pkg"
@@ -454,6 +455,48 @@ type PackageAttr struct {
 	Flag int
 }
 
+// pa holds whether a [PArtifact] is present.
+type pa = [PresetEnd]bool
+
+// paPool holds addresses of pa.
+var paPool = sync.Pool{New: func() any { return new(pa) }}
+
+// paGet returns the address of a new pa.
+func paGet() *pa { return paPool.Get().(*pa) }
+
+// paPut returns a pa to paPool.
+func paPut(pv *pa) { *pv = pa{}; paPool.Put(pv) }
+
+// appendPreset recursively appends a [PArtifact] and its runtime dependencies.
+func (t Toolchain) appendPreset(
+	a []pkg.Artifact,
+	pv *pa, p PArtifact,
+) []pkg.Artifact {
+	if pv[p] {
+		return a
+	}
+	pv[p] = true
+
+	for _, d := range GetMetadata(p).Dependencies {
+		a = t.appendPreset(a, pv, d)
+	}
+	return append(a, t.Load(p))
+}
+
+// AppendPresets recursively appends multiple [PArtifact] and their runtime
+// dependencies.
+func (t Toolchain) AppendPresets(
+	a []pkg.Artifact,
+	presets ...PArtifact,
+) []pkg.Artifact {
+	pv := paGet()
+	for _, p := range presets {
+		a = t.appendPreset(a, pv, p)
+	}
+	paPut(pv)
+	return a
+}
+
 // NewPackage constructs a [pkg.Artifact] via a build system helper.
 func (t Toolchain) NewPackage(
 	name, version string,
@@ -486,12 +529,14 @@ func (t Toolchain) NewPackage(
 	extraRes := make([]pkg.Artifact, 0, dc)
 	extraRes = append(extraRes, attr.NonStage0...)
 	if !t.isStage0() {
+		pv := paGet()
 		for _, p := range helper.extra(attr.Flag) {
-			extraRes = append(extraRes, t.Load(p))
+			extraRes = t.appendPreset(extraRes, pv, p)
 		}
 		for _, p := range extra {
-			extraRes = append(extraRes, t.Load(p))
+			extraRes = t.appendPreset(extraRes, pv, p)
 		}
+		paPut(pv)
 	}
 
 	var scriptEarly string