private static FeedResponseContext MakeFirstContextForPaging(object key)
{
var context = new FeedResponseContext();
PagingContext.Add(key, context);
return(context);
}
/// <summary>
/// This will execute a DocumentDB query in the form of an IQueryable (Linq form) and return the results.
///
/// It handles paging, continuation tokens, and retriable errors such as "too many requests" for you,
/// while aggregating all query results in-memory before returning.
/// </summary>
/// <typeparam name="R"></typeparam>
/// <param name="queryable"></param>
/// <param name="queryExecutionHandler"></param>
/// <param name="enumerationExceptionHandler"></param>
/// <param name="feedResponseHandler"></param>
/// <param name="maxRetries"></param>
/// <param name="maxTime"></param>
/// <param name="shouldRetry"></param>
/// <returns></returns>
public static async Task <IList <R> > ExecuteQueryWithContinuationAndRetry <R>(IQueryable <R> queryable, QueryExecutionHandler queryExecutionHandler, EnumerationExceptionHandler enumerationExceptionHandler, FeedResponseHandler feedResponseHandler, int maxRetries, TimeSpan maxTime, ShouldRetry shouldRetry)
{
IDocumentQuery <R> query = null;
try
{
query = queryable.AsDocumentQuery();
}
catch (Exception e)
{
throw new ArgumentException(BadQueryableMessage, e);
}
var context = new FeedResponseContext();
queryExecutionHandler(context, query.ToString());
feedResponseHandler(context, FeedResponseType.BeforeEnumeration, null);
var allResults = new List <R>();
while (query.HasMoreResults)
{
FeedResponse <R> intermediateResponse = null;
try
{
intermediateResponse = await DocumentDbReliableExecution.ExecuteResultWithRetry(() =>
query.ExecuteNextAsync <R>(),
null,
maxRetries,
maxTime,
shouldRetry);
}
catch (Exception ex)
{
bool handled = enumerationExceptionHandler(context, ex);
if (!handled)
{
feedResponseHandler(context, FeedResponseType.EnumerationAborted, null);
throw;
}
else
{
break;
}
}
// lots of interesting info in intermediateResults such as RU usage, etc.
List <R> intermediateResults = intermediateResponse.ToList();
UpdateContext <R>(context, intermediateResponse, JsonConvert.SerializeObject(intermediateResults).Length, query.HasMoreResults);
feedResponseHandler(context, FeedResponseType.PageReceived, new FeedResponseWrapper <R>(intermediateResponse));
allResults.AddRange(intermediateResults);
}
feedResponseHandler(context, FeedResponseType.AfterEnumeration, null);
return(allResults);
}
private static void UpdateContext <R>(FeedResponseContext context, FeedResponse <R> response, int resultJsonLength, bool hasMoreResults)
{
context.TotalCount += response.Count;
context.TotalRequestCharge += response.RequestCharge;
context.TotalResultsJsonStringLength += resultJsonLength;
if (!hasMoreResults)
{
context.StopTiming();
}
}
/// <summary>
/// This will execute a DocumentDB FeedResponse method and return the results.
///
/// It handles paging, continuation tokens, and retriable errors such as "too many requests" for you,
/// while streaming query results out in chunks via IEnumerable / yield.
/// </summary>
/// <typeparam name="R"></typeparam>
/// <param name="feedTakingContinuation"></param>
/// <param name="enumerationExceptionHandler"></param>
/// <param name="feedResponseHandler"></param>
/// <param name="maxRetries"></param>
/// <param name="maxTime"></param>
/// <param name="shouldRetry"></param>
/// <returns></returns>
public static IEnumerable <R> StreamFeedWithContinuationAndRetry <R>(Func <string, Task <FeedResponse <R> > > feedTakingContinuation, EnumerationExceptionHandler enumerationExceptionHandler, FeedResponseHandler feedResponseHandler, int maxRetries, TimeSpan maxTime, ShouldRetry shouldRetry)
{
var context = new FeedResponseContext();
feedResponseHandler(context, FeedResponseType.BeforeEnumeration, null);
FeedResponse <R> intermediateResponse = null;
do
{
Task <FeedResponse <R> > t;
try
{
t = Task.Run(async() => await ExecuteResultWithRetry(() =>
feedTakingContinuation(intermediateResponse?.ResponseContinuation),
null,
maxRetries,
maxTime,
shouldRetry));
t.Wait();
}
catch (Exception ex)
{
// note: if an IQueryable is returned to OData, throwing an exception here will cause it to take down w3wp.exe
bool handled = enumerationExceptionHandler(null, ex);
if (!handled)
{
feedResponseHandler(context, FeedResponseType.EnumerationAborted, null);
throw;
}
else
{
break;
}
}
intermediateResponse = t.Result;
// lots of interesting info in intermediateResults such as RU usage, etc.
List <R> intermediateResults = intermediateResponse.ToList();
UpdateContext <R>(context, intermediateResponse, JsonConvert.SerializeObject(intermediateResults).Length, !string.IsNullOrEmpty(intermediateResponse.ResponseContinuation));
feedResponseHandler(context, FeedResponseType.PageReceived, new FeedResponseWrapper <R>(intermediateResponse));
foreach (var result in intermediateResults)
{
yield return(result);
}
} while (!string.IsNullOrEmpty(intermediateResponse.ResponseContinuation));
feedResponseHandler(context, FeedResponseType.AfterEnumeration, null);
}
/// <summary>
/// This will execute a DocumentDB FeedResponse method return the results.
///
/// It handles paging, continuation tokens, and retriable errors such as "too many requests" for you,
/// while aggregating all query results in-memory before returning.
/// </summary>
/// <typeparam name="R"></typeparam>
/// <param name="feedTakingContinuation"></param>
/// <param name="enumerationExceptionHandler"></param>
/// <param name="feedResponseHandler"></param>
/// <param name="maxRetries"></param>
/// <param name="maxTime"></param>
/// <param name="shouldRetry"></param>
/// <returns></returns>
public static async Task <IList <R> > ExecuteFeedWithContinuationAndRetry <R>(Func <string, Task <FeedResponse <R> > > feedTakingContinuation, EnumerationExceptionHandler enumerationExceptionHandler, FeedResponseHandler feedResponseHandler, int maxRetries, TimeSpan maxTime, ShouldRetry shouldRetry)
{
var context = new FeedResponseContext();
feedResponseHandler(context, FeedResponseType.BeforeEnumeration, null);
var allResults = new List <R>();
FeedResponse <R> intermediateResponse = null;
do
{
try
{
intermediateResponse = await DocumentDbReliableExecution.ExecuteResultWithRetry(() =>
feedTakingContinuation(intermediateResponse?.ResponseContinuation),
null,
maxRetries,
maxTime,
shouldRetry);
}
catch (Exception ex)
{
bool handled = enumerationExceptionHandler(null, ex);
if (!handled)
{
feedResponseHandler(context, FeedResponseType.EnumerationAborted, null);
throw;
}
else
{
break;
}
}
// lots of interesting info in intermediateResults such as RU usage, etc.
List <R> intermediateResults = intermediateResponse.ToList();
UpdateContext <R>(context, intermediateResponse, JsonConvert.SerializeObject(intermediateResults).Length, !string.IsNullOrEmpty(intermediateResponse.ResponseContinuation));
feedResponseHandler(context, FeedResponseType.PageReceived, new FeedResponseWrapper <R>(intermediateResponse));
allResults.AddRange(intermediateResults);
} while (!string.IsNullOrEmpty(intermediateResponse.ResponseContinuation));
feedResponseHandler(context, FeedResponseType.AfterEnumeration, null);
return(allResults);
}
/// <summary>
/// This will execute a DocumentDB query in the form of an IQueryable (Linq form) and return the results.
///
/// It handles paging, continuation tokens, and retriable errors such as "too many requests" for you,
/// while streaming query results out in chunks via IEnumerable / yield.
/// </summary>
/// <typeparam name="R"></typeparam>
/// <param name="queryable"></param>
/// <param name="queryExecutionHandler"></param>
/// <param name="enumerationExceptionHandler"></param>
/// <param name="feedResponseHandler"></param>
/// <param name="maxRetries"></param>
/// <param name="maxTime"></param>
/// <param name="shouldRetry"></param>
/// <returns></returns>
public static IEnumerable <R> StreamQueryWithContinuationAndRetry <R>(IQueryable <R> queryable, QueryExecutionHandler queryExecutionHandler, EnumerationExceptionHandler enumerationExceptionHandler, FeedResponseHandler feedResponseHandler, int maxRetries, TimeSpan maxTime, ShouldRetry shouldRetry)
{
IDocumentQuery <R> query = null;
try
{
query = queryable.AsDocumentQuery();
}
catch (Exception e)
{
throw new ArgumentException(BadQueryableMessage, e);
}
var context = new FeedResponseContext();
queryExecutionHandler(context, query.ToString());
feedResponseHandler(context, FeedResponseType.BeforeEnumeration, null);
while (query.HasMoreResults)
{
Task <FeedResponse <R> > t;
try
{
t = Task.Run(async() => await ExecuteResultWithRetry(() =>
query.ExecuteNextAsync <R>(),
null,
maxRetries,
maxTime,
shouldRetry));
t.Wait();
}
catch (Exception ex)
{
// note: if an IQueryable is returned to OData, throwing an exception here will cause it to take down w3wp.exe
bool handled = enumerationExceptionHandler(context, ex);
if (!handled)
{
feedResponseHandler(context, FeedResponseType.EnumerationAborted, null);
throw;
}
else
{
break;
}
}
var intermediateResponse = t.Result;
// lots of interesting info in intermediateResults such as RU usage, etc.
List <R> intermediateResults = intermediateResponse.ToList();
UpdateContext <R>(context, intermediateResponse, JsonConvert.SerializeObject(intermediateResults).Length, query.HasMoreResults);
feedResponseHandler(context, FeedResponseType.PageReceived, new FeedResponseWrapper <R>(intermediateResponse));
foreach (var result in intermediateResults)
{
yield return(result);
}
}
feedResponseHandler(context, FeedResponseType.AfterEnumeration, null);
}
