/// <summary>
/// Initiates a Search object to Scan a DynamoDB table, with the
/// specified config.
///
/// No calls are made until the Search object is used.
/// </summary>
/// <param name="config">Configuration to use.</param>
/// <returns>Resultant Search container.</returns>
public Search Scan(ScanOperationConfig config)
{
var currentConfig = config ?? new ScanOperationConfig();
Search ret = new Search(SearchType.Scan)
{
SourceTable = this,
TableName = TableName,
Limit = currentConfig.Limit,
Filter = currentConfig.Filter,
FilterExpression = currentConfig.FilterExpression,
ConditionalOperator = currentConfig.ConditionalOperator,
AttributesToGet = currentConfig.AttributesToGet,
Select = currentConfig.Select,
CollectResults = currentConfig.CollectResults,
IndexName = currentConfig.IndexName
};
if (currentConfig.TotalSegments != 0)
{
ret.TotalSegments = currentConfig.TotalSegments;
ret.Segment = currentConfig.Segment;
}
return ret;
}
/// <summary>
/// Initiates a Search object to Scan a DynamoDB table, with the
/// specified config.
///
/// No calls are made until the Search object is used.
/// </summary>
/// <param name="config">Configuration to use.</param>
/// <returns>Resultant Search container.</returns>
public Search Scan(ScanOperationConfig config)
{
var currentConfig = config ?? new ScanOperationConfig();
Search ret = new Search(SearchType.Scan)
{
SourceTable = this,
TableName = TableName,
Limit = currentConfig.Limit,
Filter = currentConfig.Filter,
FilterExpression = currentConfig.FilterExpression,
ConditionalOperator = currentConfig.ConditionalOperator,
AttributesToGet = currentConfig.AttributesToGet,
Select = currentConfig.Select,
CollectResults = currentConfig.CollectResults,
IndexName = currentConfig.IndexName,
IsConsistentRead = currentConfig.ConsistentRead,
PaginationToken = currentConfig.PaginationToken
};
if (currentConfig.TotalSegments != 0)
{
ret.TotalSegments = currentConfig.TotalSegments;
ret.Segment = currentConfig.Segment;
}
return(ret);
}
/// <summary>
/// Initiates a Search object to Scan a DynamoDB table, with the
/// specified expression.
///
/// No calls are made until the Search object is used.
/// </summary>
/// <param name="filterExpression">Expression to apply to the scan.</param>
/// <returns>Resultant Search container.</returns>
public Search Scan(Expression filterExpression)
{
ScanOperationConfig config = new ScanOperationConfig
{
FilterExpression = filterExpression
};
return(Scan(config));
}
/// <summary>
/// Initiates a Search object to Scan a DynamoDB table, with the
/// specified config.
///
/// No calls are made until the Search object is used.
/// </summary>
/// <param name="config">Configuration to use.</param>
/// <returns>Resultant Search container.</returns>
public Search Scan(ScanOperationConfig config)
{
var currentConfig = config ?? new ScanOperationConfig();
Search ret = new Search(SearchType.Scan)
{
SourceTable = this,
TableName = TableName,
Limit = currentConfig.Limit,
Filter = currentConfig.Filter,
AttributesToGet = currentConfig.AttributesToGet,
Select = currentConfig.Select,
CollectResults = currentConfig.CollectResults
};
if (currentConfig.TotalSegments != 0)
{
ret.TotalSegments = currentConfig.TotalSegments;
ret.Segment = currentConfig.Segment;
}
return(ret);
}
private object ExecuteScan(TranslationResult translationResult, Type entityType)
{
var scanConfig = new ScanOperationConfig
{
Filter = translationResult.GetScanFilterForTable(this.TableDefinition),
CollectResults = false
};
if (translationResult.AttributesToGet != null)
{
scanConfig.Select = SelectValues.SpecificAttributes;
scanConfig.AttributesToGet = translationResult.AttributesToGet;
}
var searchResult = this.TableDefinition.Scan(scanConfig);
this.Log("DynamoDb scan: " + translationResult);
return this.CreateReader(searchResult, entityType, translationResult.ProjectionFunc);
}
/// <summary>
/// Initiates a Search object to Scan a DynamoDB table, with the
/// specified expression.
///
/// No calls are made until the Search object is used.
/// </summary>
/// <param name="filterExpression">Expression to apply to the scan.</param>
/// <returns>Resultant Search container.</returns>
public Search Scan(Expression filterExpression)
{
ScanOperationConfig config = new ScanOperationConfig
{
FilterExpression = filterExpression
};
return Scan(config);
}
/// <summary>
/// Initiates a Search object to Scan a DynamoDB table, with the
/// specified config.
///
/// No calls are made until the Search object is used.
/// </summary>
/// <param name="config">Configuration to use.</param>
/// <returns>Resultant Search container.</returns>
public Search Scan(ScanOperationConfig config)
{
var currentConfig = config ?? new ScanOperationConfig();
Search ret = new Search(SearchType.Scan)
{
SourceTable = this,
TableName = TableName,
Limit = currentConfig.Limit,
Filter = currentConfig.Filter,
AttributesToGet = currentConfig.AttributesToGet,
Select = currentConfig.Select
};
return ret;
}
/// <summary>
/// A utility method for cleaning up expired sessions that IIS failed to delete. The method performs a scan on the table
/// with a condition that the expiration date is in the past and calls delete on all the keys returned. Scans can be costly on performance
/// so use this method sparingly like a nightly or weekly clean job.
/// </summary>
/// <param name="dbClient">The AmazonDynamoDB client used to find a delete expired sessions.</param>
/// <param name="tableName">The table to search.</param>
public static void DeleteExpiredSessions(IAmazonDynamoDB dbClient, string tableName)
{
LogInfo("DeleteExpiredSessions");
Table table = Table.LoadTable(dbClient, tableName, DynamoDBEntryConversion.V1);
ScanFilter filter = new ScanFilter();
filter.AddCondition(ATTRIBUTE_EXPIRES, ScanOperator.LessThan, DateTime.Now);
ScanOperationConfig config = new ScanOperationConfig();
config.AttributesToGet = new List<string> { ATTRIBUTE_SESSION_ID };
config.Select = SelectValues.SpecificAttributes;
config.Filter = filter;
DocumentBatchWrite batchWrite = table.CreateBatchWrite();
Search search = table.Scan(config);
do
{
List<Document> page = search.GetNextSet();
foreach (var document in page)
{
batchWrite.AddItemToDelete(document);
}
} while (!search.IsDone);
batchWrite.Execute();
}
