feat(bigtable): add GC policy to FamilyInfo. (#6234)

* Add GC policy proto to FamilyInfo.

* Add PolicyType and expose GCPolicyObject.

* Add PolicyType alias to int.

* Add new TypedGCPolicy to prevent breaking changes

* Remove unused methods

* Address PR comments.

* Change variable name to Unspecified instead of Unknown.

* Fix go fmt.

* Address build failure.

* Add FullGCPolicy to admin.go.

Co-authored-by: Eric Schmidt <erschmid@google.com>

bigtable/admin.go

@@ -310,8 +310,9 @@ type TableInfo struct {
 
 // FamilyInfo represents information about a column family.
 type FamilyInfo struct {
-	Name     string
-	GCPolicy string
+	Name         string
+	GCPolicy     string
+	FullGCPolicy GCPolicy
 }
 
 func (ac *AdminClient) getTable(ctx context.Context, table string, view btapb.Table_View) (*btapb.Table, error) {
@@ -347,7 +348,11 @@ func (ac *AdminClient) TableInfo(ctx context.Context, table string) (*TableInfo,
 	ti := &TableInfo{}
 	for name, fam := range res.ColumnFamilies {
 		ti.Families = append(ti.Families, name)
-		ti.FamilyInfos = append(ti.FamilyInfos, FamilyInfo{Name: name, GCPolicy: GCRuleToString(fam.GcRule)})
+		ti.FamilyInfos = append(ti.FamilyInfos, FamilyInfo{
+			Name:         name,
+			GCPolicy:     GCRuleToString(fam.GcRule),
+			FullGCPolicy: gcRuleToPolicy(fam.GcRule),
+		})
 	}
 	return ti, nil
 }

bigtable/gc.go

@@ -25,6 +25,13 @@ import (
 	bttdpb "google.golang.org/genproto/googleapis/bigtable/admin/v2"
 )
 
+type policyType int
+
+const (
+	policyTypeUnion policyType = iota
+	policyTypeIntersection
+)
+
 // A GCPolicy represents a rule that determines which cells are eligible for garbage collection.
 type GCPolicy interface {
 	String() string
@@ -158,10 +165,47 @@ func GCRuleToString(rule *bttdpb.GcRule) string {
 	}
 }
 
+func gcRuleToPolicy(rule *bttdpb.GcRule) GCPolicy {
+	if rule == nil {
+		return NoGcPolicy()
+	}
+	switch r := rule.Rule.(type) {
+	case *bttdpb.GcRule_Intersection_:
+		return compoundRuleToPolicy(r.Intersection.Rules, policyTypeIntersection)
+	case *bttdpb.GcRule_Union_:
+		return compoundRuleToPolicy(r.Union.Rules, policyTypeUnion)
+	case *bttdpb.GcRule_MaxAge:
+		return MaxAgePolicy(time.Duration(r.MaxAge.Seconds) * time.Second)
+	case *bttdpb.GcRule_MaxNumVersions:
+		return MaxVersionsPolicy(int(r.MaxNumVersions))
+	default:
+		return NoGcPolicy()
+	}
+}
+
 func joinRules(rules []*bttdpb.GcRule, sep string) string {
 	var chunks []string
 	for _, r := range rules {
 		chunks = append(chunks, GCRuleToString(r))
 	}
 	return "(" + strings.Join(chunks, sep) + ")"
 }
+
+func compoundRuleToPolicy(rules []*bttdpb.GcRule, mode policyType) GCPolicy {
+	sub := []GCPolicy{}
+	for _, r := range rules {
+		p := gcRuleToPolicy(r)
+		if p.String() != "" {
+			sub = append(sub, gcRuleToPolicy(r))
+		}
+	}
+
+	switch mode {
+	case policyTypeUnion:
+		return unionPolicy{sub: sub}
+	case policyTypeIntersection:
+		return intersectionPolicy{sub: sub}
+	default:
+		return NoGcPolicy()
+	}
+}

bigtable/gc_test.go

@@ -44,3 +44,26 @@ func TestGcRuleToString(t *testing.T) {
 		}
 	}
 }
+
+func TestGCRuleToPolicy(t *testing.T) {
+	var tc = []struct {
+		proto *bttdpb.GcRule
+		want  string
+	}{
+		{MaxAgePolicy(72 * time.Hour).proto(), "age() > 3d"},
+		{MaxVersionsPolicy(5).proto(), "versions() > 5"},
+		{IntersectionPolicy(MaxAgePolicy(5*time.Hour), MaxVersionsPolicy(4)).proto(),
+			"(age() > 5h && versions() > 4)"},
+		{UnionPolicy(MaxAgePolicy(5*time.Hour), MaxVersionsPolicy(4)).proto(),
+			"(age() > 5h || versions() > 4)"},
+		{IntersectionPolicy(UnionPolicy(MaxAgePolicy(5*time.Hour), MaxVersionsPolicy(4)), MaxVersionsPolicy(8)).proto(),
+			"((age() > 5h || versions() > 4) && versions() > 8)"},
+	}
+
+	for _, test := range tc {
+		got := gcRuleToPolicy(test.proto)
+		if got.String() != test.want {
+			t.Errorf("got gc rule %v, want: %v", got, test.want)
+		}
+	}
+}