Reduce Maven version component allocations

maven_allocation_test.go

@@ -0,0 +1,79 @@
+package vers
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestMavenComponentNormalization(t *testing.T) {
+	for _, tt := range []struct {
+		a, b string
+		want int
+	}{
+		{"1.0.0-rc1", "1-rc1", 0},
+		{"1.0.0-alpha.0.1", "1-alpha.0.1", 0},
+		{"1.0.0-final", "1", 0},
+		{"0.0.0-rc1", "0-rc1", 0},
+		{"1.0.0.2-rc1", "1.0.0.2", -1},
+		{"1.0.0-sp1", "1", 1},
+		{"1.0.0-RC1", "1.0.0-rc1", 0},
+		{"1.0.0-a1", "1-alpha1", 0},
+		{"1.0.0", "1", 0},
+		{"0.0.0", "0", 0},
+		{"1.9999999999999999999999-rc1", "1.2-rc1", 1},
+	} {
+		t.Run(tt.a+"/"+tt.b, func(t *testing.T) {
+			if got := CompareWithScheme(tt.a, tt.b, "maven"); got != tt.want {
+				t.Fatalf("compare = %d, want %d", got, tt.want)
+			}
+			if got := CompareWithScheme(tt.b, tt.a, "maven"); got != -tt.want {
+				t.Fatalf("reverse compare = %d, want %d", got, -tt.want)
+			}
+		})
+	}
+	versions := []string{"1.0.0-alpha1", "1.0.0-rc1", "1.0.0", "1.0.0-sp1", "2.0.0"}
+	got, err := HighestSatisfying(versions, "[1.0,2.0)", "maven")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != "1.0.0-sp1" {
+		t.Fatalf("highest = %q", got)
+	}
+	for _, version := range []string{"1.0.0-alpha1", "1.0.0-rc1"} {
+		if !IsPrereleaseWithScheme(version, "maven") {
+			t.Fatalf("%q should be a prerelease", version)
+		}
+	}
+}
+
+func BenchmarkMavenComponents(b *testing.B) {
+	for _, tt := range []struct{ name, a, other string }{
+		{"release", "1.2.3", "1.2.4"},
+		{"prerelease", "1.2.3-rc1", "1.2.3"},
+		{"trailing_zeros", "1.0.0-rc1", "1.0.0"},
+	} {
+		b.Run(tt.name, func(b *testing.B) {
+			b.ReportAllocs()
+			for b.Loop() {
+				CompareWithScheme(tt.a, tt.other, "maven")
+			}
+		})
+	}
+	b.Run("highest_500", func(b *testing.B) {
+		versions := make([]string, 500)
+		for i := range versions {
+			versions[i] = fmt.Sprintf("1.%d.0-rc1", i)
+		}
+		b.ReportAllocs()
+		b.ResetTimer()
+		for b.Loop() {
+			got, err := HighestSatisfying(versions, "[1.0,2.0)", "maven")
+			if err != nil {
+				b.Fatal(err)
+			}
+			if got != "1.499.0-rc1" {
+				b.Fatalf("highest = %q", got)
+			}
+		}
+	})
+}

version.go

@@ -650,13 +650,15 @@ func getMavenQualifierOrder(q string) (int, bool) {
 }
 
 func parseMavenVersion(s string) []mavenComponent {
-	var result []mavenComponent
-
 	// Maven versions are split by . and - AND on transitions between digits and letters
 	s = strings.ToLower(s)
 
 	// Split on delimiters and digit/letter transitions, tracking separators
 	parts, afterDashFlags := splitMavenVersionWithSeparators(s)
+	var result []mavenComponent
+	if len(parts) > 0 {
+		result = make([]mavenComponent, 0, len(parts))
+	}
 
 	for i, part := range parts {
 		if part == "" {
@@ -719,11 +721,7 @@ func normalizeMavenComponents(components []mavenComponent) []mavenComponent {
 			baseEnd--
 		}
 		if baseEnd < firstSublistIdx {
-			// Rebuild: base without trailing zeros + sublist portion
-			newComponents := make([]mavenComponent, baseEnd)
-			copy(newComponents, components[:baseEnd])
-			newComponents = append(newComponents, components[firstSublistIdx:]...)
-			components = newComponents
+			components = append(components[:baseEnd], components[firstSublistIdx:]...)
 		}
 	} else if firstSublistIdx == -1 {
 		// No sublist - just remove trailing zeros from the end