/// <inheritdoc />
public async IAsyncEnumerable <ChangesFeedResponseResult <TSource> > GetContinuousChangesAsync(ChangesFeedOptions options, ChangesFeedFilter filter,
[EnumeratorCancellation] CancellationToken cancellationToken)
{
var infiniteTimeout = TimeSpan.FromMilliseconds(Timeout.Infinite);
IFlurlRequest request = NewRequest()
.WithTimeout(infiniteTimeout)
.AppendPathSegment("_changes")
.SetQueryParam("feed", "continuous");
if (options != null)
{
request = request.ApplyQueryParametersOptions(options);
}
await using Stream stream = filter == null
? await request.GetStreamAsync(cancellationToken, HttpCompletionOption.ResponseHeadersRead)
.ConfigureAwait(false)
: await request.QueryContinuousWithFilterAsync <TSource>(_queryProvider, filter, cancellationToken)
.ConfigureAwait(false);
await foreach (var line in stream.ReadLinesAsync(cancellationToken))
{
if (string.IsNullOrEmpty(line))
{
continue;
}
ChangesFeedResponseResult <TSource> result = JsonConvert.DeserializeObject <ChangesFeedResponseResult <TSource> >(line);
yield return(result);
}
}
/// <summary>
/// Returns changes as they happen. A continuous feed stays open and connected to the database until explicitly closed.
/// </summary>
/// <remarks>
/// To stop receiving changes call <c>Cancel()</c> on the <c>CancellationTokenSource</c> used to create the <c>CancellationToken</c>.
/// </remarks>
/// <param name="options">Options to apply to the request.</param>
/// <param name="filter">A filter to apply to the result.</param>
/// <param name="cancellationToken">A cancellation token to stop receiving changes.</param>
/// <returns></returns>
public async IAsyncEnumerable <ChangesFeedResponseResult <TSource> > GetContinuousChangesAsync(ChangesFeedOptions options, ChangesFeedFilter filter,
[EnumeratorCancellation] CancellationToken cancellationToken)
{
var infiniteTimeout = TimeSpan.FromMilliseconds(Timeout.Infinite);
IFlurlRequest request = NewRequest()
.WithTimeout(infiniteTimeout)
.AppendPathSegment("_changes")
.SetQueryParam("feed", "continuous");
SetChangesFeedOptions(request, options);
await using Stream stream = filter == null
? await request.GetStreamAsync(cancellationToken, HttpCompletionOption.ResponseHeadersRead)
.ConfigureAwait(false)
: await QueryContinuousWithFilterAsync(request, filter, cancellationToken)
.ConfigureAwait(false);
using var reader = new StreamReader(stream);
while (!cancellationToken.IsCancellationRequested && !reader.EndOfStream)
{
if (cancellationToken.IsCancellationRequested)
{
continue;
}
var line = await reader.ReadLineAsync().ConfigureAwait(false);
if (!string.IsNullOrEmpty(line))
{
yield return(JsonConvert.DeserializeObject <ChangesFeedResponseResult <TSource> >(line));
}
}
}
protected async Task <JsonDocument> GetJson(
IFlurlRequest request,
CancellationToken cancellationToken)
{
var delta = DateTime.Now - _lastRequestTime;
if (delta < RequestInterval)
{
await Task.Delay(delta, cancellationToken);
}
var result = await request.GetStreamAsync(cancellationToken);
_lastRequestTime = DateTime.Now;
return(await JsonDocument.ParseAsync(result, cancellationToken : cancellationToken));
}
/// <inheritdoc />
public async IAsyncEnumerable <ChangesFeedResponseResult <TSource> > GetContinuousChangesAsync(ChangesFeedOptions?options, ChangesFeedFilter?filter,
[EnumeratorCancellation] CancellationToken cancellationToken)
{
var infiniteTimeout = TimeSpan.FromMilliseconds(Timeout.Infinite);
IFlurlRequest request = NewRequest()
.WithTimeout(infiniteTimeout)
.AppendPathSegment("_changes")
.SetQueryParam("feed", "continuous");
if (options != null)
{
request = request.ApplyQueryParametersOptions(options);
}
await using Stream stream = filter == null
? await request.GetStreamAsync(cancellationToken, HttpCompletionOption.ResponseHeadersRead)
.ConfigureAwait(false)
: await request.QueryContinuousWithFilterAsync <TSource>(_queryProvider, filter, cancellationToken)
.ConfigureAwait(false);
await foreach (var line in stream.ReadLinesAsync(cancellationToken))
{
if (string.IsNullOrEmpty(line))
{
continue;
}
MatchCollection matches = _feedChangeLineStartPattern.Matches(line);
for (var i = 0; i < matches.Count; i++)
{
var startIndex = matches[i].Index;
var endIndex = i < matches.Count - 1 ? matches[i + 1].Index : line.Length;
var lineLength = endIndex - startIndex;
var substring = line.Substring(startIndex, lineLength);
yield return(JsonConvert.DeserializeObject <ChangesFeedResponseResult <TSource> >(substring));
}
}
}
