/// <summary>
/// Calls <c>PollQueryResult</c> in a loop until the query completes. Can be canceled.
/// </summary>
/// <remarks>
/// Canceling via the <c>CancellationToken</c> cancels the returned <c>Task</c> and
/// automatically cancels the query execution by calling <c>/api/queries/{query_id}/cancel</c>.
/// </remarks>
/// <param name="apiUrl">The Url of the Aircloak api.</param>
/// <param name="queryId">The query Id obtained via a previous call to the /api/query endpoint.</param>
/// <param name="query">An instance of the <see cref="DQuery{TRow}"/> interface.</param>
/// <param name="rowParser">A delegate used for parsing a result row.</param>
/// <param name="pollFrequency">How often to poll the api endpoint. </param>
/// <param name="cancellationToken">A <c>CancellationToken</c> that cancels the returned <c>Task</c>.</param>
/// <typeparam name="TRow">The type to use to deserialise each row returned in the query results.</typeparam>
/// <returns>A QueryResult instance. If the query has finished executing, contains the query results, with each
/// row seralised to type <c>TRow</c>.</returns>
/// <exception cref="Exceptions.ApiException">The Aircloak Api returned a Http Error code.</exception>
/// <exception cref="Exceptions.ResultException">The Aircloak Api result status is "Error".</exception>
public async Task <QueryResult <TRow> > PollQueryUntilComplete <TRow>(
Uri apiUrl,
string queryId,
string query,
JsonRowParser <TRow> rowParser,
TimeSpan pollFrequency,
CancellationToken cancellationToken)
{
// Register the JsonArrayConverter so the TRow can be deserialized correctly
var jsonDeserializeOptions = new JsonSerializerOptions
{
PropertyNamingPolicy = new SnakeCaseNamingPolicy(),
Converters = { new JsonArrayConverter <TRow>(rowParser) },
};
var queryCompleted = false;
var speed = 16;
try
{
while (true)
{
cancellationToken.ThrowIfCancellationRequested();
var endPoint = new Uri(apiUrl, $"queries/{queryId}");
using var httpResponse = await ApiGetRequest(endPoint, cancellationToken);
var queryResult = await ParseJson <QueryResult <TRow> >(httpResponse, jsonDeserializeOptions, cancellationToken);
if (queryResult.Query.Completed)
{
queryCompleted = true;
switch (queryResult.Query.QueryState)
{
case "completed":
return(queryResult);
case "error":
throw new Exceptions.ResultException("Aircloak API query error.\n" +
GetQueryResultDetails(query, queryResult));
case "cancelled":
throw new OperationCanceledException("Aircloak API query canceled.\n" +
GetQueryResultDetails(query, queryResult));
}
}
await Task.Delay(pollFrequency / speed, cancellationToken);
speed = Math.Max(speed / 2, 1);
}
}
catch (Exception)
{
if (!queryCompleted)
{
await CancelQuery(apiUrl, queryId);
}
throw;
}
/// <summary>
/// Posts a query to the Aircloak server, retrieves the query ID, and then polls for the result.
/// </summary>
/// <param name="apiUrl">The Url of the Aircloak api.</param>
/// <param name="dataSource">The data source to run the query against.</param>
/// <param name="query">The query statement as a string.</param>
/// <param name="rowParser">A delegate used for parsing a result row.</param>
/// <param name="pollFrequency">How often to poll the api endpoint. </param>
/// <param name="cancellationToken">A <see cref="CancellationToken" /> object that can be used to cancel the operation.</param>
/// <returns>A <see cref="QueryResult{TRow}"/> instance containing the success status and query Id.</returns>
/// <typeparam name="TRow">The type that the query row will be deserialized to.</typeparam>
/// <exception cref="Exceptions.ApiException">The Aircloak Api returned a Http Error code.</exception>
/// <exception cref="Exceptions.QueryException">The Aircloak Api could not process the query.</exception>
/// <exception cref="Exceptions.ResultException">The Aircloak Api result status is "Error".</exception>
public async Task <QueryResult <TRow> > Query <TRow>(
Uri apiUrl,
string dataSource,
string query,
JsonRowParser <TRow> rowParser,
TimeSpan pollFrequency,
CancellationToken cancellationToken)
{
var queryResponse = await SubmitQuery(apiUrl, dataSource, query, cancellationToken);
return(await PollQueryUntilComplete(apiUrl, queryResponse.QueryId, query, rowParser, pollFrequency, cancellationToken));
}
/// <summary>
/// Executes the query.
/// </summary>
/// <param name="query">An object defining the query to be executed.</param>
/// <param name="rowParser">A delegate used for parsing a result row.</param>
/// <typeparam name="TRow">The type of the rows returned by the query.</typeparam>
/// <returns>An object containing a collection with the rows returned by the query.</returns>
public async Task <DResult <TRow> > Exec <TRow>(string query, JsonRowParser <TRow> rowParser)
{
await semaphore.WaitAsync(cancellationToken);
try
{
return(await apiClient.Query(
apiUrl,
dataSourceName,
query,
rowParser,
pollFrequency,
cancellationToken));
}
finally
{
semaphore.Release();
}
}
public JsonArrayConverter(JsonRowParser <TRow> rowParser)
{
this.rowParser = rowParser;
}
