feat: memo filter for sqlite

plugin/filter/filter.go

@@ -0,0 +1,47 @@
+package filter
+
+import (
+	"github.com/google/cel-go/cel"
+	"github.com/pkg/errors"
+	exprv1 "google.golang.org/genproto/googleapis/api/expr/v1alpha1"
+)
+
+// MemoFilterCELAttributes are the CEL attributes for memo.
+var MemoFilterCELAttributes = []cel.EnvOption{
+	cel.Variable("content", cel.StringType),
+	cel.Variable("tag", cel.StringType),
+}
+
+// Parse parses the filter string and returns the parsed expression.
+// The filter string should be a CEL expression.
+func Parse(filter string) (expr *exprv1.ParsedExpr, err error) {
+	e, err := cel.NewEnv(MemoFilterCELAttributes...)
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to create CEL environment")
+	}
+	ast, issues := e.Compile(filter)
+	if issues != nil {
+		return nil, errors.Errorf("failed to compile filter: %v", issues)
+	}
+	return cel.AstToParsedExpr(ast)
+}
+
+// GetConstValue returns the constant value of the expression.
+func GetConstValue(expr *exprv1.Expr) (any, error) {
+	switch v := expr.ExprKind.(type) {
+	case *exprv1.Expr_ConstExpr:
+		switch v.ConstExpr.ConstantKind.(type) {
+		case *exprv1.Constant_StringValue:
+			return v.ConstExpr.GetStringValue(), nil
+		case *exprv1.Constant_Int64Value:
+			return v.ConstExpr.GetInt64Value(), nil
+		case *exprv1.Constant_Uint64Value:
+			return v.ConstExpr.GetUint64Value(), nil
+		case *exprv1.Constant_DoubleValue:
+			return v.ConstExpr.GetDoubleValue(), nil
+		case *exprv1.Constant_BoolValue:
+			return v.ConstExpr.GetBoolValue(), nil
+		}
+	}
+	return nil, errors.New("invalid constant expression")
+}