|
//------------------------------------------------------------------------------
// <copyright file="OdbcConnectionHandle.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
// <owner current="true" primary="true">Microsoft</owner>
// <owner current="true" primary="false">Microsoft</owner>
//------------------------------------------------------------------------------
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Data.Common;
using System.Diagnostics;
using System.Globalization;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Security;
using System.Security.Permissions;
using System.Text;
using System.Threading;
using System.Runtime.ConstrainedExecution;
namespace System.Data.Odbc {
sealed internal class OdbcConnectionHandle : OdbcHandle {
private HandleState _handleState;
private enum HandleState {
Allocated = 0,
Connected = 1,
Transacted = 2,
TransactionInProgress = 3,
}
internal OdbcConnectionHandle(OdbcConnection connection, OdbcConnectionString constr, OdbcEnvironmentHandle environmentHandle) : base(ODBC32.SQL_HANDLE.DBC, environmentHandle) {
if(null == connection) {
throw ADP.ArgumentNull("connection");
}
if(null == constr) {
throw ADP.ArgumentNull("constr");
}
ODBC32.RetCode retcode;
//Set connection timeout (only before open).
//Note: We use login timeout since its odbc 1.0 option, instead of using
//connectiontimeout (which affects other things besides just login) and its
//a odbc 3.0 feature. The ConnectionTimeout on the managed providers represents
//the login timeout, nothing more.
int connectionTimeout = connection.ConnectionTimeout;
retcode = SetConnectionAttribute2(ODBC32.SQL_ATTR.LOGIN_TIMEOUT, (IntPtr)connectionTimeout, (Int32)ODBC32.SQL_IS.UINTEGER);
string connectionString = constr.UsersConnectionString(false);
// Connect to the driver. (Using the connection string supplied)
//Note: The driver doesn't filter out the password in the returned connection string
//so their is no need for us to obtain the returned connection string
// Prepare to handle a ThreadAbort Exception between SQLDriverConnectW and update of the state variables
retcode = Connect(connectionString);
connection.HandleError(this, retcode);
}
private ODBC32.RetCode AutoCommitOff() {
ODBC32.RetCode retcode;
Debug.Assert(HandleState.Connected <= _handleState, "AutoCommitOff while in wrong state?");
// Avoid runtime injected errors in the following block.
// must call SQLSetConnectAttrW and set _handleState
RuntimeHelpers.PrepareConstrainedRegions();
try {} finally {
retcode = UnsafeNativeMethods.SQLSetConnectAttrW(this, ODBC32.SQL_ATTR.AUTOCOMMIT, ODBC32.SQL_AUTOCOMMIT_OFF, (Int32)ODBC32.SQL_IS.UINTEGER);
switch(retcode) {
case ODBC32.RetCode.SUCCESS:
case ODBC32.RetCode.SUCCESS_WITH_INFO:
_handleState = HandleState.Transacted;
break;
}
}
ODBC.TraceODBC(3, "SQLSetConnectAttrW", retcode);
return retcode;
}
internal ODBC32.RetCode BeginTransaction(ref IsolationLevel isolevel) {
ODBC32.RetCode retcode = ODBC32.RetCode.SUCCESS;
ODBC32.SQL_ATTR isolationAttribute;
if(IsolationLevel.Unspecified != isolevel) {
ODBC32.SQL_TRANSACTION sql_iso;
switch(isolevel) {
case IsolationLevel.ReadUncommitted:
sql_iso = ODBC32.SQL_TRANSACTION.READ_UNCOMMITTED;
isolationAttribute = ODBC32.SQL_ATTR.TXN_ISOLATION;
break;
case IsolationLevel.ReadCommitted:
sql_iso = ODBC32.SQL_TRANSACTION.READ_COMMITTED;
isolationAttribute = ODBC32.SQL_ATTR.TXN_ISOLATION;
break;
case IsolationLevel.RepeatableRead:
sql_iso = ODBC32.SQL_TRANSACTION.REPEATABLE_READ;
isolationAttribute = ODBC32.SQL_ATTR.TXN_ISOLATION;
break;
case IsolationLevel.Serializable:
sql_iso = ODBC32.SQL_TRANSACTION.SERIALIZABLE;
isolationAttribute = ODBC32.SQL_ATTR.TXN_ISOLATION;
break;
case IsolationLevel.Snapshot:
sql_iso = ODBC32.SQL_TRANSACTION.SNAPSHOT;
// VSDD 414121: Snapshot isolation level must be set through SQL_COPT_SS_TXN_ISOLATION (http://msdn.microsoft.com/en-us/library/ms131709.aspx)
isolationAttribute = ODBC32.SQL_ATTR.SQL_COPT_SS_TXN_ISOLATION;
break;
case IsolationLevel.Chaos:
throw ODBC.NotSupportedIsolationLevel(isolevel);
default:
throw ADP.InvalidIsolationLevel(isolevel);
}
//Set the isolation level (unless its unspecified)
retcode = SetConnectionAttribute2(isolationAttribute, (IntPtr)sql_iso, (Int32)ODBC32.SQL_IS.INTEGER);
//Note: The Driver can return success_with_info to indicate it "rolled" the
//isolevel to the next higher value. If this is the case, we need to requery
//the value if th euser asks for it...
//We also still propagate the info, since it could be other info as well...
if(ODBC32.RetCode.SUCCESS_WITH_INFO == retcode) {
isolevel = IsolationLevel.Unspecified;
}
}
switch(retcode) {
case ODBC32.RetCode.SUCCESS:
case ODBC32.RetCode.SUCCESS_WITH_INFO:
//Turn off auto-commit (which basically starts the transaction)
retcode = AutoCommitOff();
_handleState = HandleState.TransactionInProgress;
break;
}
return retcode;
}
internal ODBC32.RetCode CompleteTransaction(short transactionOperation) {
bool mustRelease = false;
RuntimeHelpers.PrepareConstrainedRegions();
try {
DangerousAddRef(ref mustRelease);
ODBC32.RetCode retcode = CompleteTransaction(transactionOperation, base.handle);
return retcode;
}
finally {
if (mustRelease) {
DangerousRelease();
}
}
}
[ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]
private ODBC32.RetCode CompleteTransaction(short transactionOperation, IntPtr handle) {
// must only call this code from ReleaseHandle or DangerousAddRef region
ODBC32.RetCode retcode = ODBC32.RetCode.SUCCESS;
// using ConstrainedRegions to make the native ODBC call and change the _handleState
RuntimeHelpers.PrepareConstrainedRegions();
try { } finally {
if (HandleState.TransactionInProgress == _handleState) {
retcode = UnsafeNativeMethods.SQLEndTran(HandleType, handle, transactionOperation);
if((ODBC32.RetCode.SUCCESS == retcode) || (ODBC32.RetCode.SUCCESS_WITH_INFO == retcode)) {
_handleState = HandleState.Transacted;
}
Bid.TraceSqlReturn("<odbc.SQLEndTran|API|ODBC|RET> %08X{SQLRETURN}\n", retcode);
}
if (HandleState.Transacted == _handleState) { // AutoCommitOn
retcode = UnsafeNativeMethods.SQLSetConnectAttrW(handle, ODBC32.SQL_ATTR.AUTOCOMMIT, ODBC32.SQL_AUTOCOMMIT_ON, (Int32)ODBC32.SQL_IS.UINTEGER);
_handleState = HandleState.Connected;
Bid.TraceSqlReturn("<odbc.SQLSetConnectAttr|API|ODBC|RET> %08X{SQLRETURN}\n", retcode);
}
}
//Overactive assert which fires if handle was allocated - but failed to connect to the server
//it can more legitmately fire if transaction failed to rollback - but there isn't much we can do in that situation
//Debug.Assert((HandleState.Connected == _handleState) || (HandleState.TransactionInProgress == _handleState), "not expected HandleState.Connected");
return retcode;
}
private ODBC32.RetCode Connect(string connectionString) {
Debug.Assert(HandleState.Allocated == _handleState, "SQLDriverConnect while in wrong state?");
ODBC32.RetCode retcode;
// Avoid runtime injected errors in the following block.
RuntimeHelpers.PrepareConstrainedRegions();
try {} finally {
short cbActualSize;
retcode = UnsafeNativeMethods.SQLDriverConnectW(this, ADP.PtrZero, connectionString, ODBC32.SQL_NTS, ADP.PtrZero, 0, out cbActualSize, (short)ODBC32.SQL_DRIVER.NOPROMPT);
switch(retcode) {
case ODBC32.RetCode.SUCCESS:
case ODBC32.RetCode.SUCCESS_WITH_INFO:
_handleState = HandleState.Connected;
break;
}
}
ODBC.TraceODBC(3, "SQLDriverConnectW", retcode);
return retcode;
}
override protected bool ReleaseHandle() {
// NOTE: The SafeHandle class guarantees this will be called exactly once and is non-interrutible.
ODBC32.RetCode retcode;
// must call complete the transaction rollback, change handle state, and disconnect the connection
retcode = CompleteTransaction(ODBC32.SQL_ROLLBACK, handle);
if ((HandleState.Connected == _handleState) || (HandleState.TransactionInProgress == _handleState)) {
retcode = UnsafeNativeMethods.SQLDisconnect(handle);
_handleState = HandleState.Allocated;
Bid.TraceSqlReturn("<odbc.SQLDisconnect|API|ODBC|RET> %08X{SQLRETURN}\n", retcode);
}
Debug.Assert(HandleState.Allocated == _handleState, "not expected HandleState.Allocated");
return base.ReleaseHandle();
}
internal ODBC32.RetCode GetConnectionAttribute(ODBC32.SQL_ATTR attribute, byte[] buffer, out int cbActual) {
ODBC32.RetCode retcode = UnsafeNativeMethods.SQLGetConnectAttrW(this, attribute, buffer, buffer.Length, out cbActual);
Bid.Trace("<odbc.SQLGetConnectAttr|ODBC> SQLRETURN=%d, Attribute=%d, BufferLength=%d, StringLength=%d\n", (int)retcode, (int)attribute, buffer.Length, (int)cbActual);
return retcode;
}
internal ODBC32.RetCode GetFunctions(ODBC32.SQL_API fFunction, out Int16 fExists) {
ODBC32.RetCode retcode = UnsafeNativeMethods.SQLGetFunctions(this, fFunction, out fExists);
ODBC.TraceODBC(3, "SQLGetFunctions", retcode);
return retcode;
}
internal ODBC32.RetCode GetInfo2(ODBC32.SQL_INFO info, byte[] buffer, out short cbActual) {
ODBC32.RetCode retcode = UnsafeNativeMethods.SQLGetInfoW(this, info, buffer, checked((short)buffer.Length), out cbActual);
Bid.Trace("<odbc.SQLGetInfo|ODBC> SQLRETURN=%d, InfoType=%d, BufferLength=%d, StringLength=%d\n", (int)retcode, (int)info, buffer.Length, (int)cbActual);
return retcode;
}
internal ODBC32.RetCode GetInfo1(ODBC32.SQL_INFO info, byte[] buffer) {
ODBC32.RetCode retcode = UnsafeNativeMethods.SQLGetInfoW(this, info, buffer, checked((short)buffer.Length), ADP.PtrZero);
Bid.Trace("<odbc.SQLGetInfo|ODBC> SQLRETURN=%d, InfoType=%d, BufferLength=%d\n", (int)retcode, (int)info, buffer.Length);
return retcode;
}
internal ODBC32.RetCode SetConnectionAttribute2(ODBC32.SQL_ATTR attribute, IntPtr value, Int32 length) {
ODBC32.RetCode retcode = UnsafeNativeMethods.SQLSetConnectAttrW(this, attribute, value, length);
ODBC.TraceODBC(3, "SQLSetConnectAttrW", retcode);
return retcode;
}
internal ODBC32.RetCode SetConnectionAttribute3(ODBC32.SQL_ATTR attribute, string buffer, Int32 length) {
ODBC32.RetCode retcode = UnsafeNativeMethods.SQLSetConnectAttrW(this, attribute, buffer, length);
Bid.Trace("<odbc.SQLSetConnectAttr|ODBC> SQLRETURN=%d, Attribute=%d, BufferLength=%d\n", (int)retcode, (int)attribute, buffer.Length);
return retcode;
}
internal ODBC32.RetCode SetConnectionAttribute4(ODBC32.SQL_ATTR attribute, System.Transactions.IDtcTransaction transaction, Int32 length) {
ODBC32.RetCode retcode = UnsafeNativeMethods.SQLSetConnectAttrW(this, attribute, transaction, length);
ODBC.TraceODBC(3, "SQLSetConnectAttrW", retcode);
return retcode;
}
}
}
|