public async Task <IEnumerable <T> > ExecuteQuery <T>(KsqlQuery query)
{
await using var queryStream = await _ksqlRestClient.ExecuteQueryAsync(query);
using var streamReader = new StreamReader(queryStream);
var results = new List <T>();
while (!streamReader.EndOfStream)
{
var line = await streamReader.ReadLineAsync();
if (string.IsNullOrEmpty(line))
{
continue;
}
var streamResponse = JsonConvert.DeserializeObject <StreamResponse>(line);
if (streamResponse.Row?.Columns is null || !streamResponse.Row.Columns.Any())
{
break;
}
var values = streamResponse.Row.Columns.Skip(2).SelectMany(FlattenNestedValues).ToArray();
var payload = _mapper.Map <T>(values);
results.Add(payload);
}
return(results);
}
public async Task <Stream> ExecuteQueryAsync(KsqlQuery query, CancellationToken token = default)
{
var request = JsonConvert.SerializeObject(query);
var response = await _client.SendAsync(new HttpRequestMessage(HttpMethod.Post, "")
{
Content = new StringContent(request, Encoding.UTF8, "application/vnd.ksql.v1+json"),
Headers = { { "accept", MediaTypeWithQualityHeaderValue.Parse("application/vnd.ksql.v1+json").ToString() } }
},
HttpCompletionOption.ResponseHeadersRead,
token);
return(await response.Content.ReadAsStreamAsync());
}
public static IServiceCollection AddKsqlConsumer <TRow>(this IServiceCollection services, KsqlQuery query) =>
services.AddTransient(provider =>
new KafkaKsqlConsumer <TRow>(
provider.GetService <KsqlClient>(),
query,
provider.GetService <TableMapper>()
)
);
public KafkaKsqlConsumer(KsqlClient ksqlRestClient, KsqlQuery query, TableMapper mapper)
{
_ksqlRestClient = ksqlRestClient;
_query = query;
_mapper = mapper;
}