.NET深入学习笔记(1)：DataSet和SqlDataReader性能差异深入剖析与测试(2)
protected
virtual
int
Fill(DataSet dataSet,
string
srcTable, IDataReader dataReader,
int
startRecord,
int
maxRecords)
{
int num;
IntPtr ptr;
Bid.ScopeEnter( out ptr, " <comm.DataAdapter.Fill|API> %d#, dataSet, srcTable, dataReader, startRecord, maxRecords\n " , this .ObjectID);
try
{
if (dataSet == null )
{
throw ADP.FillRequires( " dataSet " );
}
if (ADP.IsEmpty(srcTable))
{
throw ADP.FillRequiresSourceTableName( " srcTable " );
}
if (dataReader == null )
{
throw ADP.FillRequires( " dataReader " );
}
if (startRecord < 0 )
{
throw ADP.InvalidStartRecord( " startRecord " , startRecord);
}
if (maxRecords < 0 )
{
throw ADP.InvalidMaxRecords( " maxRecords " , maxRecords);
}
if (dataReader.IsClosed)
{
return 0 ;
}
DataReaderContainer container = DataReaderContainer.Create(dataReader, this .ReturnProviderSpecificTypes);
num = this .FillFromReader(dataSet, null , srcTable, container, startRecord, maxRecords, null , null );
}
finally
{
Bid.ScopeLeave( ref ptr);
}
return num;
}
{
int num;
IntPtr ptr;
Bid.ScopeEnter( out ptr, " <comm.DataAdapter.Fill|API> %d#, dataSet, srcTable, dataReader, startRecord, maxRecords\n " , this .ObjectID);
try
{
if (dataSet == null )
{
throw ADP.FillRequires( " dataSet " );
}
if (ADP.IsEmpty(srcTable))
{
throw ADP.FillRequiresSourceTableName( " srcTable " );
}
if (dataReader == null )
{
throw ADP.FillRequires( " dataReader " );
}
if (startRecord < 0 )
{
throw ADP.InvalidStartRecord( " startRecord " , startRecord);
}
if (maxRecords < 0 )
{
throw ADP.InvalidMaxRecords( " maxRecords " , maxRecords);
}
if (dataReader.IsClosed)
{
return 0 ;
}
DataReaderContainer container = DataReaderContainer.Create(dataReader, this .ReturnProviderSpecificTypes);
num = this .FillFromReader(dataSet, null , srcTable, container, startRecord, maxRecords, null , null );
}
finally
{
Bid.ScopeLeave( ref ptr);
}
return num;
}
另外一个SqlCommand 的ExecuteReader方法最终调用Run方法代码如下：
internal
bool
Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)
{
if ((TdsParserState.Broken == this .State) || ( this .State == TdsParserState.Closed))
{
return true ;
}
bool flag = false ;
Label_0016:
if (stateObj._internalTimeout)
{
runBehavior = RunBehavior.Attention;
}
if ((TdsParserState.Broken == this .State) || ( this .State == TdsParserState.Closed))
{
goto Label_06DF;
}
byte token = stateObj.ReadByte();
if ((((((token != 170 ) && (token != 0xab )) && ((token != 0xad ) && (token != 0xe3 ))) && (((token != 0xac ) && (token != 0x79 )) && ((token != 160 ) && (token != 0xa1 )))) && ((((token != 0x81 ) && (token != 0x88 )) && ((token != 0xa4 ) && (token != 0xa5 ))) && (((token != 0xa9 ) && (token != 0xd3 )) && ((token != 0xd1 ) && (token != 0xfd ))))) && ((((token != 0xfe ) && (token != 0xff )) && ((token != 0x39 ) && (token != 0xed ))) && (((token != 0xae ) && (token != 0x7c )) && ((token != 120 ) && (token != 0xed )))))
{
this ._state = TdsParserState.Broken;
this ._connHandler.BreakConnection();
throw SQL.ParsingError();
}
int tokenLength = this .GetTokenLength(token, stateObj);
switch (token)
{
case 0xa4 :
if (dataStream == null )
{
this .SkipBytes(tokenLength, stateObj);
}
else
{
dataStream.TableNames = this .ProcessTableName(tokenLength, stateObj);
}
goto Label_06AF;
case 0xa5 :
if (dataStream == null )
{
this .SkipBytes(tokenLength, stateObj);
}
else
{
_SqlMetaDataSet metaData = this .ProcessColInfo(dataStream.MetaData, dataStream, stateObj);
dataStream.SetMetaData(metaData, false );
dataStream.BrowseModeInfoConsumed = true ;
}
goto Label_06AF;
case 0xa9 :
this .SkipBytes(tokenLength, stateObj);
goto Label_06AF;
case 170 :
case 0xab :
{
if (token == 170 )
{
stateObj._errorTokenReceived = true ;
}
SqlError error = this .ProcessError(token, stateObj);
if (RunBehavior.Clean == (RunBehavior.Clean & runBehavior))
{
if (error.Class >= 20 )
{
this .Errors.Add(error);
}
}
else if ((( this ._connHandler != null ) && ( this ._connHandler.Connection != null )) && ( this ._connHandler.Connection.FireInfoMessageEventOnUserErrors && (error.Class <= 0x10 )))
{
this .FireInfoMessageEvent(stateObj, error);
}
else if (error.Class < 11 )
{
this .Warnings.Add(error);
}
else if (error.Class <= 0x10 )
{
this .Errors.Add(error);
if ((dataStream != null ) && ! dataStream.IsInitialized)
{
runBehavior = RunBehavior.UntilDone;
}
}
else
{
this .Errors.Add(error);
runBehavior = RunBehavior.UntilDone;
}
goto Label_06AF;
}
case 0xac :
{
SqlReturnValue rec = this .ProcessReturnValue(tokenLength, stateObj);
if (cmdHandler != null )
{
cmdHandler.OnReturnValue(rec);
}
goto Label_06AF;
}
case 0xad :
{
SqlLoginAck ack = this .ProcessLoginAck(stateObj);
this ._connHandler.OnLoginAck(ack);
goto Label_06AF;
}
case 0x88 :
{
if (stateObj._cleanupAltMetaDataSetArray == null )
{
stateObj._cleanupAltMetaDataSetArray = new _SqlMetaDataSetCollection();
}
_SqlMetaDataSet altMetaDataSet = this .ProcessAltMetaData(tokenLength, stateObj);
stateObj._cleanupAltMetaDataSetArray.Add(altMetaDataSet);
if (dataStream != null )
{
dataStream.SetAltMetaDataSet(altMetaDataSet, 0x88 != stateObj.PeekByte());
}
goto Label_06AF;
}
case 0x79 :
{
int status = stateObj.ReadInt32();
if (cmdHandler != null )
{
cmdHandler.OnReturnStatus(status);
}
goto Label_06AF;
}
case 0x81 :
if (tokenLength != 0xffff )
{
stateObj._cleanupMetaData = this .ProcessMetaData(tokenLength, stateObj);
}
else if (cmdHandler != null )
{
stateObj._cleanupMetaData = cmdHandler.MetaData;
}
if (dataStream != null )
{
byte num5 = stateObj.PeekByte();
dataStream.SetMetaData(stateObj._cleanupMetaData, ( 0xa4 == num5) || ( 0xa5 == num5));
}
else if (bulkCopyHandler != null )
{
bulkCopyHandler.SetMetaData(stateObj._cleanupMetaData);
}
goto Label_06AF;
case 0xd1 :
if (bulkCopyHandler == null )
{
if (RunBehavior.ReturnImmediately != (RunBehavior.ReturnImmediately & runBehavior))
{
this .SkipRow(stateObj._cleanupMetaData, stateObj);
}
break ;
}
this .ProcessRow(stateObj._cleanupMetaData, bulkCopyHandler.CreateRowBuffer(), bulkCopyHandler.CreateIndexMap(), stateObj);
break ;
case 0xd3 :
if (RunBehavior.ReturnImmediately != (RunBehavior.ReturnImmediately & runBehavior))
{
int num8 = stateObj.ReadUInt16();
this .SkipRow(stateObj._cleanupAltMetaDataSetArray[num8], stateObj);
}
flag = true ;
goto Label_06AF;
case 0xe3 :
{
SqlEnvChange[] changeArray = this .ProcessEnvChange(tokenLength, stateObj);
for ( int i = 0 ; i < changeArray.Length; i ++ )
{
if (changeArray[i] == null )
{
continue ;
}
switch (changeArray[i].type)
{
case 8 :
case 11 :
this ._currentTransaction = this ._pendingTransaction;
this ._pendingTransaction = null ;
if ( this ._currentTransaction == null )
{
break ;
}
this ._currentTransaction.TransactionId = changeArray[i].newLongValue;
goto Label_048E;
case 9 :
case 12 :
case 0x11 :
this ._retainedTransactionId = 0L ;
goto Label_04D1;
case 10 :
goto Label_04D1;
default :
goto Label_0551;
}
TransactionType type = ( 8 == changeArray[i].type) ? TransactionType.LocalFromTSQL : TransactionType.Distributed;
this ._currentTransaction = new SqlInternalTransaction( this ._connHandler, type, null , changeArray[i].newLongValue);
Label_048E:
if (( this ._statistics != null ) && ! this ._statisticsIsInTransaction)
{
this ._statistics.SafeIncrement( ref this ._statistics._transactions);
}
this ._statisticsIsInTransaction = true ;
this ._retainedTransactionId = 0L ;
continue ;
Label_04D1:
if ( this ._currentTransaction != null )
{
if ( 9 == changeArray[i].type)
{
this ._currentTransaction.Completed(TransactionState.Committed);
}
else if ( 10 == changeArray[i].type)
{
if ( this ._currentTransaction.IsDistributed && this ._currentTransaction.IsActive)
{
this ._retainedTransactionId = changeArray[i].oldLongValue;
}
this ._currentTransaction.Completed(TransactionState.Aborted);
}
else
{
this ._currentTransaction.Completed(TransactionState.Unknown);
}
this ._currentTransaction = null ;
}
this ._statisticsIsInTransaction = false ;
continue ;
Label_0551:
this ._connHandler.OnEnvChange(changeArray[i]);
}
goto Label_06AF;
}
case 0xfd :
case 0xfe :
case 0xff :
this .ProcessDone(cmdHandler, dataStream, ref runBehavior, stateObj);
if ((token == 0xfe ) && (cmdHandler != null ))
{
cmdHandler.OnDoneProc();
}
goto Label_06AF;
case 0xed :
this .ProcessSSPI(tokenLength);
goto Label_06AF;
default :
goto Label_06AF;
}
if ( this ._statistics != null )
{
this ._statistics.WaitForDoneAfterRow = true ;
}
flag = true ;
Label_06AF:
if ((stateObj._pendingData && (RunBehavior.ReturnImmediately != (RunBehavior.ReturnImmediately & runBehavior))) || (( ! stateObj._pendingData && stateObj._attentionSent) && ! stateObj._attentionReceived))
{
goto Label_0016;
}
Label_06DF:
if ( ! stateObj._pendingData && ( this .CurrentTransaction != null ))
{
this .CurrentTransaction.Activate();
}
if (stateObj._attentionSent && stateObj._attentionReceived)
{
stateObj._attentionSent = false ;
stateObj._attentionReceived = false ;
if ((RunBehavior.Clean != (RunBehavior.Clean & runBehavior)) && ! stateObj._internalTimeout)
{
this .Errors.Add( new SqlError( 0 , 0 , 11 , this ._server, SQLMessage.OperationCancelled(), "" , 0 ));
}
}
if (( this ._errors != null ) || ( this ._warnings != null ))
{
this .ThrowExceptionAndWarning(stateObj);
}
return flag;
}
{
if ((TdsParserState.Broken == this .State) || ( this .State == TdsParserState.Closed))
{
return true ;
}
bool flag = false ;
Label_0016:
if (stateObj._internalTimeout)
{
runBehavior = RunBehavior.Attention;
}
if ((TdsParserState.Broken == this .State) || ( this .State == TdsParserState.Closed))
{
goto Label_06DF;
}
byte token = stateObj.ReadByte();
if ((((((token != 170 ) && (token != 0xab )) && ((token != 0xad ) && (token != 0xe3 ))) && (((token != 0xac ) && (token != 0x79 )) && ((token != 160 ) && (token != 0xa1 )))) && ((((token != 0x81 ) && (token != 0x88 )) && ((token != 0xa4 ) && (token != 0xa5 ))) && (((token != 0xa9 ) && (token != 0xd3 )) && ((token != 0xd1 ) && (token != 0xfd ))))) && ((((token != 0xfe ) && (token != 0xff )) && ((token != 0x39 ) && (token != 0xed ))) && (((token != 0xae ) && (token != 0x7c )) && ((token != 120 ) && (token != 0xed )))))
{
this ._state = TdsParserState.Broken;
this ._connHandler.BreakConnection();
throw SQL.ParsingError();
}
int tokenLength = this .GetTokenLength(token, stateObj);
switch (token)
{
case 0xa4 :
if (dataStream == null )
{
this .SkipBytes(tokenLength, stateObj);
}
else
{
dataStream.TableNames = this .ProcessTableName(tokenLength, stateObj);
}
goto Label_06AF;
case 0xa5 :
if (dataStream == null )
{
this .SkipBytes(tokenLength, stateObj);
}
else
{
_SqlMetaDataSet metaData = this .ProcessColInfo(dataStream.MetaData, dataStream, stateObj);
dataStream.SetMetaData(metaData, false );
dataStream.BrowseModeInfoConsumed = true ;
}
goto Label_06AF;
case 0xa9 :
this .SkipBytes(tokenLength, stateObj);
goto Label_06AF;
case 170 :
case 0xab :
{
if (token == 170 )
{
stateObj._errorTokenReceived = true ;
}
SqlError error = this .ProcessError(token, stateObj);
if (RunBehavior.Clean == (RunBehavior.Clean & runBehavior))
{
if (error.Class >= 20 )
{
this .Errors.Add(error);
}
}
else if ((( this ._connHandler != null ) && ( this ._connHandler.Connection != null )) && ( this ._connHandler.Connection.FireInfoMessageEventOnUserErrors && (error.Class <= 0x10 )))
{
this .FireInfoMessageEvent(stateObj, error);
}
else if (error.Class < 11 )
{
this .Warnings.Add(error);
}
else if (error.Class <= 0x10 )
{
this .Errors.Add(error);
if ((dataStream != null ) && ! dataStream.IsInitialized)
{
runBehavior = RunBehavior.UntilDone;
}
}
else
{
this .Errors.Add(error);
runBehavior = RunBehavior.UntilDone;
}
goto Label_06AF;
}
case 0xac :
{
SqlReturnValue rec = this .ProcessReturnValue(tokenLength, stateObj);
if (cmdHandler != null )
{
cmdHandler.OnReturnValue(rec);
}
goto Label_06AF;
}
case 0xad :
{
SqlLoginAck ack = this .ProcessLoginAck(stateObj);
this ._connHandler.OnLoginAck(ack);
goto Label_06AF;
}
case 0x88 :
{
if (stateObj._cleanupAltMetaDataSetArray == null )
{
stateObj._cleanupAltMetaDataSetArray = new _SqlMetaDataSetCollection();
}
_SqlMetaDataSet altMetaDataSet = this .ProcessAltMetaData(tokenLength, stateObj);
stateObj._cleanupAltMetaDataSetArray.Add(altMetaDataSet);
if (dataStream != null )
{
dataStream.SetAltMetaDataSet(altMetaDataSet, 0x88 != stateObj.PeekByte());
}
goto Label_06AF;
}
case 0x79 :
{
int status = stateObj.ReadInt32();
if (cmdHandler != null )
{
cmdHandler.OnReturnStatus(status);
}
goto Label_06AF;
}
case 0x81 :
if (tokenLength != 0xffff )
{
stateObj._cleanupMetaData = this .ProcessMetaData(tokenLength, stateObj);
}
else if (cmdHandler != null )
{
stateObj._cleanupMetaData = cmdHandler.MetaData;
}
if (dataStream != null )
{
byte num5 = stateObj.PeekByte();
dataStream.SetMetaData(stateObj._cleanupMetaData, ( 0xa4 == num5) || ( 0xa5 == num5));
}
else if (bulkCopyHandler != null )
{
bulkCopyHandler.SetMetaData(stateObj._cleanupMetaData);
}
goto Label_06AF;
case 0xd1 :
if (bulkCopyHandler == null )
{
if (RunBehavior.ReturnImmediately != (RunBehavior.ReturnImmediately & runBehavior))
{
this .SkipRow(stateObj._cleanupMetaData, stateObj);
}
break ;
}
this .ProcessRow(stateObj._cleanupMetaData, bulkCopyHandler.CreateRowBuffer(), bulkCopyHandler.CreateIndexMap(), stateObj);
break ;
case 0xd3 :
if (RunBehavior.ReturnImmediately != (RunBehavior.ReturnImmediately & runBehavior))
{
int num8 = stateObj.ReadUInt16();
this .SkipRow(stateObj._cleanupAltMetaDataSetArray[num8], stateObj);
}
flag = true ;
goto Label_06AF;
case 0xe3 :
{
SqlEnvChange[] changeArray = this .ProcessEnvChange(tokenLength, stateObj);
for ( int i = 0 ; i < changeArray.Length; i ++ )
{
if (changeArray[i] == null )
{
continue ;
}
switch (changeArray[i].type)
{
case 8 :
case 11 :
this ._currentTransaction = this ._pendingTransaction;
this ._pendingTransaction = null ;
if ( this ._currentTransaction == null )
{
break ;
}
this ._currentTransaction.TransactionId = changeArray[i].newLongValue;
goto Label_048E;
case 9 :
case 12 :
case 0x11 :
this ._retainedTransactionId = 0L ;
goto Label_04D1;
case 10 :
goto Label_04D1;
default :
goto Label_0551;
}
TransactionType type = ( 8 == changeArray[i].type) ? TransactionType.LocalFromTSQL : TransactionType.Distributed;
this ._currentTransaction = new SqlInternalTransaction( this ._connHandler, type, null , changeArray[i].newLongValue);
Label_048E:
if (( this ._statistics != null ) && ! this ._statisticsIsInTransaction)
{
this ._statistics.SafeIncrement( ref this ._statistics._transactions);
}
this ._statisticsIsInTransaction = true ;
this ._retainedTransactionId = 0L ;
continue ;
Label_04D1:
if ( this ._currentTransaction != null )
{
if ( 9 == changeArray[i].type)
{
this ._currentTransaction.Completed(TransactionState.Committed);
}
else if ( 10 == changeArray[i].type)
{
if ( this ._currentTransaction.IsDistributed && this ._currentTransaction.IsActive)
{
this ._retainedTransactionId = changeArray[i].oldLongValue;
}
this ._currentTransaction.Completed(TransactionState.Aborted);
}
else
{
this ._currentTransaction.Completed(TransactionState.Unknown);
}
this ._currentTransaction = null ;
}
this ._statisticsIsInTransaction = false ;
continue ;
Label_0551:
this ._connHandler.OnEnvChange(changeArray[i]);
}
goto Label_06AF;
}
case 0xfd :
case 0xfe :
case 0xff :
this .ProcessDone(cmdHandler, dataStream, ref runBehavior, stateObj);
if ((token == 0xfe ) && (cmdHandler != null ))
{
cmdHandler.OnDoneProc();
}
goto Label_06AF;
case 0xed :
this .ProcessSSPI(tokenLength);
goto Label_06AF;
default :
goto Label_06AF;
}
if ( this ._statistics != null )
{
this ._statistics.WaitForDoneAfterRow = true ;
}
flag = true ;
Label_06AF:
if ((stateObj._pendingData && (RunBehavior.ReturnImmediately != (RunBehavior.ReturnImmediately & runBehavior))) || (( ! stateObj._pendingData && stateObj._attentionSent) && ! stateObj._attentionReceived))
{
goto Label_0016;
}
Label_06DF:
if ( ! stateObj._pendingData && ( this .CurrentTransaction != null ))
{
this .CurrentTransaction.Activate();
}
if (stateObj._attentionSent && stateObj._attentionReceived)
{
stateObj._attentionSent = false ;
stateObj._attentionReceived = false ;
if ((RunBehavior.Clean != (RunBehavior.Clean & runBehavior)) && ! stateObj._internalTimeout)
{
this .Errors.Add( new SqlError( 0 , 0 , 11 , this ._server, SQLMessage.OperationCancelled(), "" , 0 ));
}
}
if (( this ._errors != null ) || ( this ._warnings != null ))
{
this .ThrowExceptionAndWarning(stateObj);
}
return flag;
}
我已经使用Reflector查看了SQLDataAdapter类型的Fill方法以及SqlCommand.ExecuteReader 方法代码。确实有使用DataReader的地方。他们是真正负责处理查询并装在数据。DataReader和DataSet应该都是数据容器。做个类比的话，应该是茶壶和茶杯的关系。至于查询数据，除了取决于容器，还和具体负责查询和装载数据的类有关系。 我文章的标题，应该说是有问题的，这种比较忽略了一个数据查询和装载的过程。有不合理的地方。现在更正。