frostfs-node/pkg/morph/client/balance/client.go

120 lines
3 KiB
Go
Raw Normal View History

2020-07-24 13:54:03 +00:00
package balance
import (
"errors"
"github.com/nspcc-dev/neofs-node/pkg/morph/client"
)
// Client is a wrapper over StaticClient
// which makes calls with the names and arguments
// of the NeoFS Balance contract.
//
// Working client must be created via constructor New.
// Using the Client that has been created with new(Client)
// expression (or just declaring a Client variable) is unsafe
// and can lead to panic.
type Client struct {
client *client.StaticClient // static Balance contract client
*cfg // contract method names
}
// ErrNilClient is returned by functions that expect
// a non-nil Client pointer, but received nil.
var ErrNilClient = errors.New("balance contract client is nil")
// Option is a client configuration change function.
type Option func(*cfg)
type cfg struct {
transferXMethod, // transferX method name for invocation
2020-07-24 13:54:03 +00:00
balanceOfMethod, // balanceOf method name for invocation
decimalsMethod string // decimals method name for invocation
}
const (
defaultTransferXMethod = "transferX" // default "transferX" method name
2020-07-24 13:54:03 +00:00
defaultBalanceOfMethod = "balanceOf" // default "balance of" method name
defaultDecimalsMethod = "decimals" // default decimals method name
)
func defaultConfig() *cfg {
return &cfg{
transferXMethod: defaultTransferXMethod,
2020-07-24 13:54:03 +00:00
balanceOfMethod: defaultBalanceOfMethod,
decimalsMethod: defaultDecimalsMethod,
}
}
// New creates, initializes and returns the Client instance.
//
// If StaticClient is nil, client.ErrNilStaticClient is returned.
//
// Other values are set according to provided options, or by default:
// * "balance of" method name: balanceOf;
// * decimals method name: decimals.
//
// If desired option satisfies the default value, it can be omitted.
// If multiple options of the same config value are supplied,
// the option with the highest index in the arguments will be used.
func New(c *client.StaticClient, opts ...Option) (*Client, error) {
if c == nil {
return nil, client.ErrNilStaticClient
}
res := &Client{
client: c,
cfg: defaultConfig(), // build default configuration
}
// apply options
for _, opt := range opts {
opt(res.cfg)
}
return res, nil
}
// WithBalanceOfMethod returns a client constructor option that
// specifies the "balance of" method name.
//
// Ignores empty value.
//
// If option not provided, "balanceOf" is used.
func WithBalanceOfMethod(n string) Option {
return func(c *cfg) {
if n != "" {
c.balanceOfMethod = n
}
}
}
// WithDecimalsMethod returns a client constructor option that
// specifies the method name of decimals receiving operation.
//
// Ignores empty value.
//
// If option not provided, "decimals" is used.
func WithDecimalsMethod(n string) Option {
return func(c *cfg) {
if n != "" {
c.decimalsMethod = n
}
}
}
// WithTransferXMethod returns a client constructor option that
// specifies the "transferX" method name.
//
// Ignores empty value.
//
// If option not provided, "transferX" is used.
func WithTransferXMethod(n string) Option {
return func(c *cfg) {
if n != "" {
c.transferXMethod = n
}
}
}