public async Task <BatchResult> PutAsync(IEnumerable <T> entities)
{
#region Preconditions
if (entities == null)
{
throw new ArgumentNullException(nameof(entities));
}
#endregion
var sw = Stopwatch.StartNew();
var result = new BatchResult();
// Batch in groups of 25
foreach (var batch in entities.Batch(25))
{
await PutBatch(batch, result).ConfigureAwait(false);
}
result.ResponseTime = sw.Elapsed;
return(result);
}
private async Task <BatchResult> PutBatch(IEnumerable <T> entities, BatchResult result)
{
#region Preconditions
if (entities == null)
{
throw new ArgumentNullException(nameof(entities));
}
#endregion
// Up to 25 items put or delete operations, with the request size not exceeding 1 MB.
var putRequests = entities
.Select(e => (ItemRequest) new PutRequest(AttributeCollection.FromObject(e, metadata)))
.ToList();
var tableBatch = new TableRequests(tableName, putRequests);
await BatchWriteItem(tableBatch, result).ConfigureAwait(false);
result.BatchCount++;
return(result);
}
public async Task <BatchResult> PutAsync(IEnumerable <T> entities)
{
var sw = Stopwatch.StartNew();
var result = new BatchResult();
// Batch in groups of 25
foreach (IEnumerable <T> batch in entities.Batch(25))
{
await PutBatch(batch, result).ConfigureAwait(false);
}
result.ResponseTime = sw.Elapsed;
return(result);
}
private async Task <BatchWriteItemResult> BatchWriteItem(TableRequests batch, BatchResult info)
{
#region Preconditions
if (batch == null)
{
throw new ArgumentNullException(nameof(batch));
}
if (batch.Requests.Count > 25)
{
throw new ArgumentException("Must be 25 or less.", "batch.Items");
}
#endregion
var retryCount = 0;
Exception lastError = null;
while (retryPolicy.ShouldRetry(retryCount))
{
try
{
var result = await client.BatchWriteItem(batch).ConfigureAwait(false);
info.ItemCount += batch.Requests.Count;
info.RequestCount++;
// Recursively process any item
foreach (var unprocessedBatch in result.UnprocessedItems)
{
await Task.Delay(100).ConfigureAwait(false); // Slow down
info.ItemCount -= unprocessedBatch.Requests.Count;
result = await BatchWriteItem(unprocessedBatch, info).ConfigureAwait(false);
}
return(result);
}
catch (DynamoDbException ex) when(ex.IsTransient)
{
lastError = ex;
}
retryCount++;
await Task.Delay(retryPolicy.GetDelay(retryCount)).ConfigureAwait(false);
}
throw lastError;
}