public Task <AppendResult> Append(UnversionedCommit commit)
{
lock (_sync)
{
var all = _commits.Where(d => d.TenantId == commit.TenantId && d.EntityId == commit.EntityId);
var dup = all.FirstOrDefault(d => d.CommitId == commit.CommitId);
if (dup != null)
{
return(Task.FromResult(new AppendResult(dup)));
}
var max = !all.Any()?0:all.Max(d => d.Version);
var c = new Commit(max + 1, commit);
_commits.Add(c);
}
return(Task.FromResult(AppendResult.Ok));
}
public async Task <AppendResult> Append(UnversionedCommit commit)
{
using (var db = await _db.CreateAsync(CancellationToken.None))
{
using (var t = db.BeginTransaction())
{
var max = await db.QueryValueAsync <int?>(q =>
q.From <Commit>().Where(d => d.EntityId == commit.EntityId && d.TenantId == commit.TenantId)
.Select(d => d.Max(d.Version)).MapTo <int?>(), CancellationToken.None).ConfigureFalse() ?? 0;
var com = new Commit(max + 1, commit);
try
{
await db.InsertAsync(com, CancellationToken.None).ConfigureFalse();
t.Commit();
return(AppendResult.Ok);
}
catch (DbException ex)
{
if (ex.Message.Contains(DuplicateCommmitMessage))
{
var existing = await db
.QueryRowAsync <Commit>(
q => q.From <Commit>()
.Where(d => d.CommitId == commit.CommitId && d.EntityId == commit.EntityId && d.TenantId == commit.TenantId)
.Limit(1)
.SelectAll(useAsterisk: true), CancellationToken.None).ConfigureFalse();
return(new AppendResult(existing));
}
if (ex.Message.Contains(DuplicateVersion))
{
throw new ConcurrencyException();
}
throw;
}
}
}
}