gecko/vms/spchainvm/state.go

118 lines
2.7 KiB
Go

// (c) 2019-2020, Ava Labs, Inc. All rights reserved.
// See the file LICENSE for licensing terms.
package spchainvm
import (
"github.com/ava-labs/gecko/database"
"github.com/ava-labs/gecko/ids"
"github.com/ava-labs/gecko/snow/choices"
"github.com/ava-labs/gecko/utils/wrappers"
)
// state is a thin wrapper around a database to provide, caching, serialization,
// and de-serialization.
type state struct{}
// Block attempts to load a block from storage.
func (s *state) Block(db database.Database, id ids.ID) (*Block, error) {
bytes, err := db.Get(id.Bytes())
if err != nil {
return nil, err
}
// The key was in the database
c := Codec{}
return c.UnmarshalBlock(bytes)
}
// SetBlock saves the provided block to storage.
func (s *state) SetBlock(db database.Database, id ids.ID, block *Block) error {
if block == nil {
return db.Delete(id.Bytes())
}
return db.Put(id.Bytes(), block.bytes)
}
// Account attempts to load an account from storage.
func (s *state) Account(db database.Database, id ids.ID) (Account, error) {
bytes, err := db.Get(id.Bytes())
if err != nil {
return Account{}, err
}
// The key was in the database
codec := Codec{}
return codec.UnmarshalAccount(bytes)
}
// SetAccount saves the provided account to storage.
func (s *state) SetAccount(db database.Database, id ids.ID, account Account) error {
codec := Codec{}
bytes, err := codec.MarshalAccount(account)
if err != nil {
return err
}
return db.Put(id.Bytes(), bytes)
}
// Status returns a status from storage.
func (s *state) Status(db database.Database, id ids.ID) (choices.Status, error) {
bytes, err := db.Get(id.Bytes())
if err != nil {
return choices.Unknown, err
}
// The key was in the database
p := wrappers.Packer{Bytes: bytes}
status := choices.Status(p.UnpackInt())
if p.Offset != len(bytes) {
p.Add(errExtraSpace)
}
if p.Errored() {
return choices.Unknown, p.Err
}
return status, nil
}
// SetStatus saves a status in storage.
func (s *state) SetStatus(db database.Database, id ids.ID, status choices.Status) error {
if status == choices.Unknown {
return db.Delete(id.Bytes())
}
p := wrappers.Packer{Bytes: make([]byte, 4)}
p.PackInt(uint32(status))
if p.Offset != len(p.Bytes) {
p.Add(errExtraSpace)
}
if p.Errored() {
return p.Err
}
return db.Put(id.Bytes(), p.Bytes)
}
// Alias returns an ID from storage.
func (s *state) Alias(db database.Database, id ids.ID) (ids.ID, error) {
bytes, err := db.Get(id.Bytes())
if err != nil {
return ids.ID{}, err
}
// The key was in the database
return ids.ToID(bytes)
}
// SetAlias saves an id in storage.
func (s *state) SetAlias(db database.Database, id ids.ID, alias ids.ID) error {
if alias.IsZero() {
return db.Delete(id.Bytes())
}
return db.Put(id.Bytes(), alias.Bytes())
}