private async Task <bool> DeserializeAsync <TState>(ILog log, IHaveState <TState> stateHolder, ISnapshotRepository <TState> repository)
{
await log.WriteInfoAsync(nameof(DeserializeAsync), "", "Loading state...");
var state = await repository.TryGetAsync();
if (state == null)
{
await log.WriteWarningAsync("SnapshotSerializer", nameof(DeserializeAsync),
stateHolder.GetType().Name, "No snapshot found to deserialize");
return(false);
}
string stateDescription;
try
{
stateDescription = stateHolder.DescribeState(state);
}
catch (NotSupportedException)
{
await log.WriteWarningAsync(nameof(DeserializeAsync), "", "Not supported, skipping");
return(false);
}
await log.WriteInfoAsync(nameof(DeserializeAsync), stateDescription, "Settings state...");
try
{
stateHolder.SetState(state);
}
catch (NotSupportedException)
{
await log.WriteWarningAsync(nameof(DeserializeAsync), "", "Not supported, skipping");
return(false);
}
await log.WriteInfoAsync(nameof(DeserializeAsync), "", "State was set");
return(true);
}
public async Task DeserializeAsync()
{
await _log.WriteInfoAsync(nameof(DeserializeAsync), "", "Loading state...");
var state = await _repository.TryGetAsync();
if (state == null)
{
await _log.WriteWarningAsync("SnapshotSerializer", nameof(DeserializeAsync),
_stateHolder.GetType().Name, "No snapshot found to deserialize");
return;
}
await _log.WriteInfoAsync(nameof(DeserializeAsync), _stateHolder.DescribeState(state), "Settings state...");
_stateHolder.SetState(state);
await _log.WriteInfoAsync(nameof(DeserializeAsync), "", "State was set");
}
public async Task CreateSnapshotAsync(
DateTime from,
DateTime to)
{
_log.Info($"Creating balance snapshot for {from:s} - {to:s}...");
var snapshotBalances = (await _balanceUpdateRepository
.GetAsync(from, to))
.OrderBy(x => x.EventTimestamp)
.GroupBy(x => x.WalletId)
.ToDictionary(x => x.Key, x => x.Select(y => y.NewBalance).Last());
_log.Info($"{snapshotBalances.Count} balance updates found");
var previousSnapshot = await _snapshotRepository.TryGetAsync(from);
if (previousSnapshot != null)
{
_log.Info($"Previous snapshot found with {previousSnapshot.Balances.Count} balances");
foreach (var balance in previousSnapshot.Balances)
{
if (!snapshotBalances.ContainsKey(balance.WalletId))
{
snapshotBalances[balance.WalletId] = balance.Value;
}
}
}
var newSnapshot = SnapshotAggregate.CreateOrRestore
(
balances: snapshotBalances.Select(x => SnapshotAggregate.Balance.CreateOrRestore
(
balance: x.Value,
walletId: x.Key
)),
timestamp: to
);
await _snapshotRepository.SaveAsync(newSnapshot);
}