IAsyncResult invokeScan(ScanRequest scanRequest, AsyncCallback callback, object state, bool synchronized)
{
IRequest irequest = new ScanRequestMarshaller().Marshall(scanRequest);
var unmarshaller = ScanResponseUnmarshaller.GetInstance();
AsyncResult result = new AsyncResult(irequest, callback, state, synchronized, signer, unmarshaller);
Invoke(result);
return result;
}
/// <summary>
/// Initiates the asynchronous execution of the Scan operation.
/// <seealso cref="Amazon.DynamoDB.AmazonDynamoDB.Scan"/>
/// </summary>
///
/// <param name="scanRequest">Container for the necessary parameters to execute the Scan operation on AmazonDynamoDB.</param>
/// <param name="callback">An AsyncCallback delegate that is invoked when the operation completes.</param>
/// <param name="state">A user-defined state object that is passed to the callback procedure. Retrieve this object from within the callback
/// procedure using the AsyncState property.</param>
///
/// <returns>An IAsyncResult that can be used to poll or wait for results, or both; this value is also needed when invoking EndScan
/// operation.</returns>
public IAsyncResult BeginScan(ScanRequest scanRequest, AsyncCallback callback, object state)
{
return invokeScan(scanRequest, callback, state, false);
}
/// <summary>
/// <para>Retrieves one or more items and its attributes by performing a full scan of a table.</para> <para>Provide a <c>ScanFilter</c> to get
/// more specific results.</para>
/// </summary>
///
/// <param name="scanRequest">Container for the necessary parameters to execute the Scan service method on AmazonDynamoDB.</param>
///
/// <returns>The response from the Scan service method, as returned by AmazonDynamoDB.</returns>
///
/// <exception cref="ProvisionedThroughputExceededException"/>
/// <exception cref="InternalServerErrorException"/>
/// <exception cref="ResourceNotFoundException"/>
public ScanResponse Scan(ScanRequest scanRequest)
{
IAsyncResult asyncResult = invokeScan(scanRequest, null, null, true);
return EndScan(asyncResult);
}
/// <summary>
/// <para> The Scan operation returns one or more items and its attributes by performing a full scan of a table. Limit the returned results by
/// specifying a filter. </para>
/// </summary>
///
/// <param name="scanRequest">Container for the necessary parameters to execute the Scan service method on AmazonDynamoDB.</param>
///
/// <returns>The response from the Scan service method, as returned by AmazonDynamoDB.</returns>
///
/// <exception cref="ProvisionedThroughputExceededException"/>
/// <exception cref="InternalServerErrorException"/>
/// <exception cref="ResourceNotFoundException"/>
public ScanResponse Scan(ScanRequest scanRequest)
{
IRequest<ScanRequest> request = new ScanRequestMarshaller().Marshall(scanRequest);
ScanResponse response = Invoke<ScanRequest, ScanResponse> (request, this.signer, ScanResponseUnmarshaller.GetInstance());
return response;
}
private List<Document> GetNextSetHelper(bool isAsync)
{
List<Document> ret = new List<Document>();
if (!IsDone)
{
switch (SearchMethod)
{
case SearchType.Scan:
ScanRequest scanReq = new ScanRequest
{
ExclusiveStartKey = NextKey,
Limit = Limit,
TableName = TableName
};
scanReq.BeforeRequestEvent += isAsync ?
new RequestEventHandler(SourceTable.UserAgentRequestEventHandlerAsync) :
new RequestEventHandler(SourceTable.UserAgentRequestEventHandlerSync);
if (AttributesToGet != null)
scanReq.AttributesToGet = AttributesToGet;
scanReq.ScanFilter = (ScanFilter)Filter;
ScanResult scanResult = SourceTable.DDBClient.Scan(scanReq).ScanResult;
foreach (var item in scanResult.Items)
{
Document doc = Document.FromAttributeMap(item);
ret.Add(doc);
Matches.Add(doc);
}
NextKey = scanResult.LastEvaluatedKey;
if (NextKey == null)
{
IsDone = true;
}
return ret;
case SearchType.Query:
QueryRequest queryReq = new QueryRequest
{
ConsistentRead=IsConsistentRead,
ExclusiveStartKey=NextKey,
HashKeyValue=HashKey,
Limit=Limit,
ScanIndexForward=!IsBackwardSearch,
TableName=TableName,
};
if (Filter != null)
queryReq.RangeKeyCondition = ((RangeFilter)Filter).Condition;
queryReq.BeforeRequestEvent += isAsync ?
new RequestEventHandler(SourceTable.UserAgentRequestEventHandlerAsync) :
new RequestEventHandler(SourceTable.UserAgentRequestEventHandlerSync);
if (AttributesToGet != null)
queryReq.AttributesToGet = AttributesToGet;
QueryResult queryResult = SourceTable.DDBClient.Query(queryReq).QueryResult;
foreach (var item in queryResult.Items)
{
Document doc = Document.FromAttributeMap(item);
ret.Add(doc);
Matches.Add(doc);
}
NextKey = queryResult.LastEvaluatedKey;
if (NextKey == null)
{
IsDone = true;
}
return ret;
default:
throw new InvalidOperationException("Unknown Search Method");
}
}
return ret;
}
private int GetCount()
{
if (IsDone)
{
return Matches.Count;
}
else
{
if (count != -1)
{
return count;
}
else
{
switch (SearchMethod)
{
case SearchType.Scan:
ScanRequest scanReq = new ScanRequest
{
Count=true,
ExclusiveStartKey=NextKey,
TableName=TableName,
};
scanReq.BeforeRequestEvent += SourceTable.UserAgentRequestEventHandlerSync;
scanReq.ScanFilter = (ScanFilter)Filter;
ScanResult scanResult = SourceTable.DDBClient.Scan(scanReq).ScanResult;
count = Matches.Count + scanResult.Count;
return count;
case SearchType.Query:
QueryRequest queryReq = new QueryRequest
{
ConsistentRead=IsConsistentRead,
Count=true,
ExclusiveStartKey=NextKey,
HashKeyValue=HashKey,
RangeKeyCondition = ((RangeFilter)Filter).Condition,
ScanIndexForward=!IsBackwardSearch,
TableName=TableName,
};
queryReq.BeforeRequestEvent += SourceTable.UserAgentRequestEventHandlerSync;
QueryResult queryResult = SourceTable.DDBClient.Query(queryReq).QueryResult;
count = Matches.Count + queryResult.Count;
return count;
default:
throw new InvalidOperationException("Unknown Search Method");
}
}
}
}
private int GetCount()
{
if (IsDone)
{
return Matches.Count;
}
else
{
if (count != -1)
{
return count;
}
else
{
switch (SearchMethod)
{
case SearchType.Scan:
ScanRequest scanReq = new ScanRequest()
.WithCount(true)
.WithExclusiveStartKey(NextKey)
.WithTableName(TableName)
.WithBeforeRequestHandler(SourceTable.UserAgentRequestEventHandlerSync) as ScanRequest;
scanReq.ScanFilter = (ScanFilter)Filter;
ScanResult scanResult = SourceTable.DDBClient.Scan(scanReq).ScanResult;
count = Matches.Count + scanResult.Count;
return count;
case SearchType.Query:
QueryRequest queryReq = new QueryRequest()
.WithConsistentRead(IsConsistentRead)
.WithCount(true)
.WithExclusiveStartKey(NextKey)
.WithHashKeyValue(HashKey)
.WithRangeKeyCondition(((RangeFilter)Filter).Condition)
.WithScanIndexForward(!IsBackwardSearch)
.WithTableName(TableName)
.WithBeforeRequestHandler(SourceTable.UserAgentRequestEventHandlerSync) as QueryRequest;
QueryResult queryResult = SourceTable.DDBClient.Query(queryReq).QueryResult;
count = Matches.Count + queryResult.Count;
return count;
default:
throw new InvalidOperationException("Unknown Search Method");
}
}
}
}
/// <summary>
/// Retrieves the next set (page) of results
/// </summary>
/// <returns>Next set of Documents matching the search parameters</returns>
public List<Document> GetNextSet()
{
List<Document> ret = new List<Document>();
if (!IsDone)
{
switch (SearchMethod)
{
case SearchType.Scan:
ScanRequest scanReq = new ScanRequest()
.WithExclusiveStartKey(NextKey)
.WithLimit(Limit)
.WithTableName(TableName)
.WithBeforeRequestHandler(SourceTable.UserAgentRequestEventHandler) as ScanRequest;
if (AttributesToGet != null)
scanReq.AttributesToGet = AttributesToGet;
scanReq.ScanFilter = (ScanFilter)Filter;
ScanResult scanResult = SourceTable.DDBClient.Scan(scanReq).ScanResult;
foreach (var item in scanResult.Items)
{
Document doc = Document.FromAttributeMap(item);
ret.Add(doc);
Matches.Add(doc);
}
NextKey = scanResult.LastEvaluatedKey;
if (NextKey == null)
{
IsDone = true;
}
return ret;
case SearchType.Query:
QueryRequest queryReq = new QueryRequest()
.WithConsistentRead(IsConsistentRead)
.WithExclusiveStartKey(NextKey)
.WithHashKeyValue(HashKey)
.WithLimit(Limit)
.WithRangeKeyCondition(((RangeFilter)Filter).Condition)
.WithScanIndexForward(!IsBackwardSearch)
.WithTableName(TableName)
.WithBeforeRequestHandler(SourceTable.UserAgentRequestEventHandler) as QueryRequest;
if (AttributesToGet !=null)
queryReq.AttributesToGet = AttributesToGet;
QueryResult queryResult = SourceTable.DDBClient.Query(queryReq).QueryResult;
foreach (var item in queryResult.Items)
{
Document doc = Document.FromAttributeMap(item);
ret.Add(doc);
Matches.Add(doc);
}
NextKey = queryResult.LastEvaluatedKey;
if (NextKey == null)
{
IsDone = true;
}
return ret;
default:
throw new InvalidOperationException("Unknown Search Method");
}
}
return ret;
}