public CachedScriptTable(DbCache <UInt160, ContractState> contracts)
 {
     this.contracts = contracts;
 }
        private void Persist(Block block)
        {
            WriteBatch batch = new WriteBatch();
            DbCache <UInt160, AccountState>     accounts     = new DbCache <UInt160, AccountState>(db, DataEntryPrefix.ST_Account);
            DbCache <UInt256, UnspentCoinState> unspentcoins = new DbCache <UInt256, UnspentCoinState>(db, DataEntryPrefix.ST_Coin);
            DbCache <UInt256, SpentCoinState>   spentcoins   = new DbCache <UInt256, SpentCoinState>(db, DataEntryPrefix.ST_SpentCoin);
            DbCache <ECPoint, ValidatorState>   validators   = new DbCache <ECPoint, ValidatorState>(db, DataEntryPrefix.ST_Validator);
            DbCache <UInt256, AssetState>       assets       = new DbCache <UInt256, AssetState>(db, DataEntryPrefix.ST_Asset);
            DbCache <UInt160, ContractState>    contracts    = new DbCache <UInt160, ContractState>(db, DataEntryPrefix.ST_Contract);
            DbCache <StorageKey, StorageItem>   storages     = new DbCache <StorageKey, StorageItem>(db, DataEntryPrefix.ST_Storage);
            long amount_sysfee = GetSysFeeAmount(block.PrevHash) + (long)block.Transactions.Sum(p => p.SystemFee);

            batch.Put(SliceBuilder.Begin(DataEntryPrefix.DATA_Block).Add(block.Hash), SliceBuilder.Begin().Add(amount_sysfee).Add(block.Trim()));
            foreach (Transaction tx in block.Transactions)
            {
                batch.Put(SliceBuilder.Begin(DataEntryPrefix.DATA_Transaction).Add(tx.Hash), SliceBuilder.Begin().Add(block.Index).Add(tx.ToArray()));
                unspentcoins.Add(tx.Hash, new UnspentCoinState
                {
                    Items = Enumerable.Repeat(CoinState.Confirmed, tx.Outputs.Length).ToArray()
                });
                foreach (TransactionOutput output in tx.Outputs)
                {
                    AccountState account = accounts.GetAndChange(output.ScriptHash, () => new AccountState
                    {
                        ScriptHash = output.ScriptHash,
                        IsFrozen   = false,
                        Votes      = new ECPoint[0],
                        Balances   = new Dictionary <UInt256, Fixed8>()
                    });
                    if (account.Balances.ContainsKey(output.AssetId))
                    {
                        account.Balances[output.AssetId] += output.Value;
                    }
                    else
                    {
                        account.Balances[output.AssetId] = output.Value;
                    }
                }
                foreach (var group in tx.Inputs.GroupBy(p => p.PrevHash))
                {
                    int         height;
                    Transaction tx_prev = GetTransaction(ReadOptions.Default, group.Key, out height);
                    foreach (CoinReference input in group)
                    {
                        unspentcoins.GetAndChange(input.PrevHash).Items[input.PrevIndex] |= CoinState.Spent;
                        if (tx_prev.Outputs[input.PrevIndex].AssetId.Equals(SystemShare.Hash))
                        {
                            spentcoins.GetAndChange(input.PrevHash, () => new SpentCoinState
                            {
                                TransactionHash   = input.PrevHash,
                                TransactionHeight = (uint)height,
                                Items             = new Dictionary <ushort, uint>()
                            }).Items.Add(input.PrevIndex, block.Index);
                        }
                        accounts.GetAndChange(tx_prev.Outputs[input.PrevIndex].ScriptHash).Balances[tx_prev.Outputs[input.PrevIndex].AssetId] -= tx_prev.Outputs[input.PrevIndex].Value;
                    }
                }
                switch (tx.Type)
                {
                case TransactionType.RegisterTransaction:
                {
                    RegisterTransaction rtx = (RegisterTransaction)tx;
                    assets.Add(tx.Hash, new AssetState
                        {
                            AssetId    = rtx.Hash,
                            AssetType  = rtx.AssetType,
                            Name       = rtx.Name,
                            Amount     = rtx.Amount,
                            Available  = Fixed8.Zero,
                            Precision  = rtx.Precision,
                            Fee        = Fixed8.Zero,
                            FeeAddress = new UInt160(),
                            Owner      = rtx.Owner,
                            Admin      = rtx.Admin,
                            Issuer     = rtx.Admin,
                            Expiration = block.Index + 2000000,
                            IsFrozen   = false
                        });
                }
                break;

                case TransactionType.IssueTransaction:
                    foreach (TransactionResult result in tx.GetTransactionResults().Where(p => p.Amount < Fixed8.Zero))
                    {
                        assets.GetAndChange(result.AssetId).Available -= result.Amount;
                    }
                    break;

                case TransactionType.ClaimTransaction:
                    foreach (CoinReference input in ((ClaimTransaction)tx).Claims)
                    {
                        if (spentcoins.TryGet(input.PrevHash)?.Items.Remove(input.PrevIndex) == true)
                        {
                            spentcoins.GetAndChange(input.PrevHash);
                        }
                    }
                    break;

                case TransactionType.EnrollmentTransaction:
                {
                    EnrollmentTransaction enroll_tx = (EnrollmentTransaction)tx;
                    validators.Add(enroll_tx.PublicKey, new ValidatorState
                        {
                            PublicKey = enroll_tx.PublicKey
                        });
                }
                break;

                case TransactionType.PublishTransaction:
                {
                    PublishTransaction publish_tx = (PublishTransaction)tx;
                    contracts.GetOrAdd(publish_tx.Code.ScriptHash, () => new ContractState
                        {
                            Code        = publish_tx.Code,
                            HasStorage  = publish_tx.NeedStorage,
                            Name        = publish_tx.Name,
                            CodeVersion = publish_tx.CodeVersion,
                            Author      = publish_tx.Author,
                            Email       = publish_tx.Email,
                            Description = publish_tx.Description
                        });
                }
                break;

                case TransactionType.InvocationTransaction:
                {
                    InvocationTransaction itx          = (InvocationTransaction)tx;
                    CachedScriptTable     script_table = new CachedScriptTable(contracts);
                    StateMachine          service      = new StateMachine(accounts, validators, assets, contracts, storages);
                    ApplicationEngine     engine       = new ApplicationEngine(itx, script_table, service, itx.Gas);
                    engine.LoadScript(itx.Script, false);
                    if (engine.Execute())
                    {
                        service.Commit();
                    }
                }
                break;
                }
            }
            accounts.DeleteWhere((k, v) => !v.IsFrozen && v.Votes.Length == 0 && v.Balances.All(p => p.Value <= Fixed8.Zero));
            accounts.Commit(batch);
            unspentcoins.DeleteWhere((k, v) => v.Items.All(p => p.HasFlag(CoinState.Spent)));
            unspentcoins.Commit(batch);
            spentcoins.DeleteWhere((k, v) => v.Items.Count == 0);
            spentcoins.Commit(batch);
            validators.Commit(batch);
            assets.Commit(batch);
            HashSet <UInt160> contracts_deleted = new HashSet <UInt160>(contracts.GetChangeSet().Where(p => p.State == TrackState.Deleted).Select(p => p.Key));

            contracts.Commit(batch);
            if (contracts_deleted.Count > 0)
            {
                storages.DeleteWhere((k, v) => contracts_deleted.Contains(k.ScriptHash));
            }
            storages.Commit(batch);
            foreach (UInt160 script_hash in contracts_deleted)
            {
                foreach (Slice key in db.Find(ReadOptions.Default, SliceBuilder.Begin(DataEntryPrefix.ST_Storage).Add(script_hash), (k, v) => k))
                {
                    batch.Delete(key);
                }
            }
            batch.Put(SliceBuilder.Begin(DataEntryPrefix.SYS_CurrentBlock), SliceBuilder.Begin().Add(block.Hash).Add(block.Index));
            db.Write(WriteOptions.Default, batch);
            current_block_height = block.Index;
        }