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/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Data / System / Data / Odbc / OdbcHandle.cs / 1305376 / OdbcHandle.cs
//------------------------------------------------------------------------------ //// Copyright (c) Microsoft Corporation. All rights reserved. // //[....] //[....] //----------------------------------------------------------------------------- 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 { internal abstract class OdbcHandle : SafeHandle { private ODBC32.SQL_HANDLE _handleType; private OdbcHandle _parentHandle; protected OdbcHandle(ODBC32.SQL_HANDLE handleType, OdbcHandle parentHandle) : base(IntPtr.Zero, true) { _handleType = handleType; bool mustRelease = false; ODBC32.RetCode retcode = ODBC32.RetCode.SUCCESS; // using ConstrainedRegions to make the native ODBC call and AddRef the parent RuntimeHelpers.PrepareConstrainedRegions(); try { // validate handleType switch(handleType) { case ODBC32.SQL_HANDLE.ENV: Debug.Assert(null == parentHandle, "did not expect a parent handle"); retcode = UnsafeNativeMethods.SQLAllocHandle(handleType, IntPtr.Zero, out base.handle); break; case ODBC32.SQL_HANDLE.DBC: case ODBC32.SQL_HANDLE.STMT: // must addref before calling native so it won't be released just after Debug.Assert(null != parentHandle, "expected a parent handle"); // safehandle can't be null parentHandle.DangerousAddRef(ref mustRelease); retcode = UnsafeNativeMethods.SQLAllocHandle(handleType, parentHandle, out base.handle); break; // case ODBC32.SQL_HANDLE.DESC: default: Debug.Assert(false, "unexpected handleType"); break; } } finally { if (mustRelease) { switch(handleType) { case ODBC32.SQL_HANDLE.DBC: case ODBC32.SQL_HANDLE.STMT: if (IntPtr.Zero != base.handle) { // must assign _parentHandle after a handle is actually created // since ReleaseHandle will only call DangerousRelease if a handle exists _parentHandle = parentHandle; } else { // without a handle, ReleaseHandle may not be called parentHandle.DangerousRelease(); } break; } } } Bid.TraceSqlReturn("%08X{SQLRETURN}\n", retcode); if((ADP.PtrZero == base.handle) || (ODBC32.RetCode.SUCCESS != retcode)) { // throw ODBC.CantAllocateEnvironmentHandle(retcode); } } internal OdbcHandle(OdbcStatementHandle parentHandle, ODBC32.SQL_ATTR attribute) : base(IntPtr.Zero, true) { Debug.Assert((ODBC32.SQL_ATTR.APP_PARAM_DESC == attribute) || (ODBC32.SQL_ATTR.APP_ROW_DESC == attribute), "invalid attribute"); _handleType = ODBC32.SQL_HANDLE.DESC; int cbActual; ODBC32.RetCode retcode; bool mustRelease = false; RuntimeHelpers.PrepareConstrainedRegions(); try { // must addref before calling native so it won't be released just after parentHandle.DangerousAddRef(ref mustRelease); retcode = parentHandle.GetStatementAttribute(attribute, out base.handle, out cbActual); } finally { if (mustRelease) { if (IntPtr.Zero != base.handle) { // must call DangerousAddRef after a handle is actually created // since ReleaseHandle will only call DangerousRelease if a handle exists _parentHandle = parentHandle; } else { // without a handle, ReleaseHandle may not be called parentHandle.DangerousRelease(); } } } if (ADP.PtrZero == base.handle) { throw ODBC.FailedToGetDescriptorHandle(retcode); } // no info-message handle on getting a descriptor handle } internal ODBC32.SQL_HANDLE HandleType { get { return _handleType; } } public override bool IsInvalid { get { // we should not have a parent if we do not have a handle return (IntPtr.Zero == base.handle); } } override protected bool ReleaseHandle() { // NOTE: The SafeHandle class guarantees this will be called exactly once and is non-interrutible. IntPtr handle = base.handle; base.handle = IntPtr.Zero; if (IntPtr.Zero != handle) { ODBC32.SQL_HANDLE handleType = HandleType; switch (handleType) { case ODBC32.SQL_HANDLE.DBC: // Disconnect happens in OdbcConnectionHandle.ReleaseHandle case ODBC32.SQL_HANDLE.ENV: case ODBC32.SQL_HANDLE.STMT: ODBC32.RetCode retcode = UnsafeNativeMethods.SQLFreeHandle(handleType, handle); Bid.TraceSqlReturn(" %08X{SQLRETURN}\n", retcode); break; case ODBC32.SQL_HANDLE.DESC: // nothing to free on the handle break; // case 0: ThreadAbortException setting handle before HandleType default: Debug.Assert(ADP.PtrZero == handle, "unknown handle type"); break; } } // If we ended up getting released, then we have to release // our reference on our parent. OdbcHandle parentHandle = _parentHandle; _parentHandle = null; if (null != parentHandle) { parentHandle.DangerousRelease(); parentHandle = null; } return true; } internal ODBC32.RetCode GetDiagnosticField (out string sqlState) { short cbActual; // ODBC (MSDN) documents it expects a buffer large enough to hold 5(+L'\0') unicode characters StringBuilder sb = new StringBuilder(6); ODBC32.RetCode retcode = UnsafeNativeMethods.SQLGetDiagFieldW( HandleType, this, (short)1, ODBC32.SQL_DIAG_SQLSTATE, sb, checked((short)(2*sb.Capacity)), // expects number of bytes, see \\kbinternal\kb\articles\294\1\69.HTM out cbActual); ODBC.TraceODBC(3, "SQLGetDiagFieldW", retcode); if ((retcode == ODBC32.RetCode.SUCCESS) || (retcode == ODBC32.RetCode.SUCCESS_WITH_INFO)) { sqlState = sb.ToString(); } else { sqlState = ADP.StrEmpty; } return retcode; } internal ODBC32.RetCode GetDiagnosticRecord(short record, out string sqlState, StringBuilder message, out int nativeError, out short cchActual) { // ODBC (MSDN) documents it expects a buffer large enough to hold 4(+L'\0') unicode characters StringBuilder sb = new StringBuilder(5); ODBC32.RetCode retcode = UnsafeNativeMethods.SQLGetDiagRecW(HandleType, this, record, sb, out nativeError, message, checked((short)message.Capacity), out cchActual); ODBC.TraceODBC(3, "SQLGetDiagRecW", retcode); if ((retcode == ODBC32.RetCode.SUCCESS) || (retcode == ODBC32.RetCode.SUCCESS_WITH_INFO)) { sqlState = sb.ToString(); } else { sqlState = ADP.StrEmpty; } return retcode; } } sealed internal class OdbcDescriptorHandle : OdbcHandle { internal OdbcDescriptorHandle(OdbcStatementHandle statementHandle, ODBC32.SQL_ATTR attribute) : base(statementHandle, attribute) { } internal ODBC32.RetCode GetDescriptionField(int i, ODBC32.SQL_DESC attribute, CNativeBuffer buffer, out int numericAttribute) { ODBC32.RetCode retcode = UnsafeNativeMethods.SQLGetDescFieldW(this, checked((short)i), attribute, buffer, buffer.ShortLength, out numericAttribute); ODBC.TraceODBC(3, "SQLGetDescFieldW", retcode); return retcode; } internal ODBC32.RetCode SetDescriptionField1(short ordinal, ODBC32.SQL_DESC type, IntPtr value) { ODBC32.RetCode retcode = UnsafeNativeMethods.SQLSetDescFieldW(this, ordinal, type, value, 0); ODBC.TraceODBC(3, "SQLSetDescFieldW", retcode); return retcode; } internal ODBC32.RetCode SetDescriptionField2(short ordinal, ODBC32.SQL_DESC type, HandleRef value) { ODBC32.RetCode retcode = UnsafeNativeMethods.SQLSetDescFieldW(this, ordinal, type, value, 0); ODBC.TraceODBC(3, "SQLSetDescFieldW", retcode); return retcode; } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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