DBBindings.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / FX-1434 / FX-1434 / 1.0 / untmp / whidbey / REDBITS / ndp / fx / src / Data / System / Data / OleDb / DBBindings.cs / 1 / DBBindings.cs
                        

                        
                            //------------------------------------------------------------------------------ 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// [....] 
// [....]
//----------------------------------------------------------------------------- 
 
namespace System.Data.OleDb {
 
    using System;
    using System.ComponentModel;
    using System.Diagnostics;
    using System.Data; 
    using System.Data.Common;
    using System.Globalization; 
    using System.Runtime.InteropServices; 
    using System.Security;
    using System.Security.Permissions; 
    using System.Text;
    using System.Threading;

    sealed internal class Bindings { 

        private readonly tagDBPARAMBINDINFO[] _bindInfo; 
        private readonly tagDBBINDING[] _dbbindings; 
        private readonly tagDBCOLUMNACCESS[] _dbcolumns;
 
        private OleDbParameter[] _parameters;
        private int _collectionChangeID;

        private OleDbDataReader _dataReader; 
        private ColumnBinding[] _columnBindings;
        private RowBinding _rowBinding; 
 
        private int _index;
        private int _count; 
        private int _dataBufferSize;
        private bool _ifIRowsetElseIRow;
        private bool _forceRebind;
        private bool _needToReset; 

        private Bindings(int count) { 
            _count = count; 

             _dbbindings = new tagDBBINDING[count]; 
            for(int i = 0;i < _dbbindings.Length;++i) {
                _dbbindings[i] = new tagDBBINDING();
            }
            _dbcolumns = new tagDBCOLUMNACCESS[count]; 
        }
 
        internal Bindings(OleDbParameter[] parameters, int collectionChangeID) : this(parameters.Length) { 
            _bindInfo = new tagDBPARAMBINDINFO[parameters.Length];
            _parameters = parameters; 
            _collectionChangeID = collectionChangeID;
            _ifIRowsetElseIRow = true;
        }
 
        internal Bindings(OleDbDataReader dataReader, bool ifIRowsetElseIRow, int count) : this(count) {
            _dataReader = dataReader; 
            _ifIRowsetElseIRow = ifIRowsetElseIRow; 
        }
 
        internal tagDBPARAMBINDINFO[] BindInfo {
            get { return _bindInfo; }
        }
        internal tagDBCOLUMNACCESS[] DBColumnAccess { 
            get { return _dbcolumns; }
        } 
 
        internal int CurrentIndex {
            //get { return _index; } 
            set {
                Debug.Assert((0 <= value) &&  (value < _count), "bad binding index");
                _index = value;
            } 
        }
 
        internal ColumnBinding[] ColumnBindings() { 
            Debug.Assert(null != _columnBindings, "null ColumnBindings");
            return _columnBindings; 
        }

        internal OleDbParameter[] Parameters() {
            Debug.Assert(null != _parameters, "null Parameters"); 
            return _parameters;
        } 
 
        internal RowBinding RowBinding() {
            //Debug.Assert(null != _rowBinding, "null RowBinding"); 
            return _rowBinding;
        }

        internal bool ForceRebind { 
            get { return _forceRebind; }
            set { _forceRebind = value; } 
        } 

        // tagDBPARAMBINDINFO member access 
        internal IntPtr DataSourceType {
            //get { return _bindInfo[_index].pwszDataSourceType; }
            set {
                _bindInfo[_index].pwszDataSourceType = value; 
            }
        } 
        internal IntPtr Name { 
            //get { return _bindInfo[_index].pwszName; }
            set { 
                _bindInfo[_index].pwszName= value;
            }
        }
        internal IntPtr ParamSize { 
            get {
                if (null != _bindInfo) { 
                    return _bindInfo[_index].ulParamSize; 
                }
                return IntPtr.Zero; 
            }
            set {
                _bindInfo[_index].ulParamSize= value;
            } 
        }
        internal int Flags { 
            //get { return _bindInfo[_index].dwFlag; } 
            set {
                _bindInfo[_index].dwFlags= value; 
            }
        }

        // tagDBBINDING member access 
        //
        internal IntPtr Ordinal { // iOrdinal 
            //get { return _dbbindings[_index].iOrdinal.ToInt32(); } 
            set {
                _dbbindings[_index].iOrdinal = value; 
            }
        }
#if DEBUG
        /*internal int ValueOffset { // obValue 
            get { return _dbbindings[_index].obValue.ToInt32(); }
        } 
        internal int LengthOffset { // obLength 
            get { return _dbbindings[_index].obLength.ToInt32(); }
        } 
        internal int StatusOffset { // obStatus
            get { return _dbbindings[_index].obStatus.ToInt32(); }
        }*/
#endif 
        internal int Part { // dwPart
#if DEBUG 
            //get { return _dbbindings[_index].dwPart; } 
#endif
            set { _dbbindings[_index].dwPart = value; } 
        }
        internal int ParamIO { // eParamIO
#if DEBUG
            //get { return _dbbindings[_index].eParamIO; } 
#endif
            set { _dbbindings[_index].eParamIO = value; } 
        } 
        internal int MaxLen { // cbMaxLen
            //get { return (int) _dbbindings[_index].cbMaxLen; } 
            set {
                Debug.Assert(0 <= value, "invalid MaxLen");

                _dbbindings[_index].obStatus = (IntPtr) (_dataBufferSize +  0); 
                _dbbindings[_index].obLength = (IntPtr) (_dataBufferSize +  ADP.PtrSize);
                _dbbindings[_index].obValue  = (IntPtr) (_dataBufferSize +  ADP.PtrSize + ADP.PtrSize); 
                _dataBufferSize += ADP.PtrSize + ADP.PtrSize; 

                switch(DbType) { 
                case (NativeDBType.BSTR):  // ADP.PtrSize
                case (NativeDBType.HCHAPTER): // ADP.PtrSize
                case (NativeDBType.PROPVARIANT): // sizeof(PROPVARIANT)
                case (NativeDBType.VARIANT): // 16 or 24 (8 + ADP.PtrSize *2) 
                case (NativeDBType.BYREF | NativeDBType.BYTES): // ADP.PtrSize
                case (NativeDBType.BYREF | NativeDBType.WSTR): // ADP.PtrSize 
                    // allocate extra space to cache original value for disposal 
                    _dataBufferSize += System.Data.OleDb.RowBinding.AlignDataSize(value*2);
                    _needToReset = true; 
                    break;
                default:
                    _dataBufferSize += System.Data.OleDb.RowBinding.AlignDataSize(value);
                    break; 
                }
 
                _dbbindings[_index].cbMaxLen = (IntPtr)value; 
                _dbcolumns[_index].cbMaxLen = (IntPtr)value;
            } 
        }
        internal int DbType { // wType
            get { return _dbbindings[_index].wType; }
            set { 
                _dbbindings[_index].wType = (short) value;
                _dbcolumns[_index].wType = (short) value; 
            } 
        }
        internal byte Precision { // bPrecision 
#if DEBUG
            //get { return _dbbindings[_index].bPrecision; }

#endif 
            set {
                if (null != _bindInfo) { 
                    _bindInfo[_index].bPrecision = value; 
                }
                _dbbindings[_index].bPrecision = value; 
                _dbcolumns[_index].bPrecision = value;
            }
        }
        internal byte Scale { // bScale 
#if DEBUG
            //get { return _dbbindings[_index].bScale; } 
#endif 
            set {
                if (null != _bindInfo) { 
                    _bindInfo[_index].bScale = value;
                }
                _dbbindings[_index].bScale = value;
                _dbcolumns[_index].bScale = value; 
            }
        } 
 
        internal int AllocateForAccessor(OleDbDataReader dataReader, int indexStart, int indexForAccessor) {
            Debug.Assert(null == _rowBinding, "row binding already allocated"); 
            Debug.Assert(null == _columnBindings, "column bindings already allocated");

            RowBinding rowBinding = System.Data.OleDb.RowBinding.CreateBuffer(_count, _dataBufferSize, _needToReset);
            _rowBinding = rowBinding; 

            ColumnBinding[] columnBindings = rowBinding.SetBindings(dataReader, this, indexStart, indexForAccessor, _parameters, _dbbindings, _ifIRowsetElseIRow); 
            Debug.Assert(null != columnBindings, "null column bindings"); 
            _columnBindings = columnBindings;
 
            if (!_ifIRowsetElseIRow) {
                Debug.Assert(columnBindings.Length == _dbcolumns.Length, "length mismatch");
                for(int i = 0; i < columnBindings.Length; ++i) { // WebData 94427
                    _dbcolumns[i].pData = rowBinding.DangerousGetDataPtr(columnBindings[i].ValueOffset); // We are simply pointing at a location later in the buffer, so we're OK to not addref the buffer. 
                }
            } 
 
#if DEBUG
            int index = -1; 
            foreach(ColumnBinding binding in columnBindings) {
                Debug.Assert(index < binding.Index, "invaild index");
                index = binding.Index;
            } 
#endif
            return (indexStart + columnBindings.Length); 
        } 

 
        internal void ApplyInputParameters() {
            ColumnBinding[] columnBindings = this.ColumnBindings();
            OleDbParameter[] parameters = this.Parameters();
 
            RowBinding().StartDataBlock();
            for(int i = 0; i < parameters.Length; ++i) { 
                if (ADP.IsDirection(parameters[i], ParameterDirection.Input)) { 
                    columnBindings[i].SetOffset(parameters[i].Offset); // MDAC 80657
                    columnBindings[i].Value(parameters[i].GetCoercedValue()); 
                }
                else {
                    // always set ouput only and return value parameter values to null when executing
                    parameters[i].Value = null; 

                    //columnBindings[i].SetValueEmpty(); // webdata 115079 
                } 
            }
        } 

        internal void ApplyOutputParameters() {
            ColumnBinding[] columnBindings = this.ColumnBindings();
            OleDbParameter[] parameters = this.Parameters(); 

            for(int i = 0; i < parameters.Length; ++i) { 
                if (ADP.IsDirection(parameters[i], ParameterDirection.Output)) { 
                    parameters[i].Value = columnBindings[i].Value();
                } 
            }
            CleanupBindings();
        }
 
        internal bool AreParameterBindingsInvalid(OleDbParameterCollection collection) {
            Debug.Assert(null != collection, "null parameter collection"); 
            Debug.Assert(null != _parameters, "null parameters"); 

            ColumnBinding[] columnBindings = this.ColumnBindings(); 
            if (!ForceRebind && ((collection.ChangeID == _collectionChangeID) && (_parameters.Length == collection.Count))) {
                for(int i = 0; i < columnBindings.Length; ++i) {
                    ColumnBinding binding = columnBindings[i];
 
                    Debug.Assert(null != binding, "null column binding");
                    Debug.Assert(binding.Parameter() == _parameters[i], "parameter mismatch"); 
                    if (binding.IsParameterBindingInvalid(collection[i])) { 
                        //Debug.WriteLine("ParameterBindingsInvalid");
                        return true; 
                    }
                }
                //Debug.WriteLine("ParameterBindingsValid");
                return false; // collection and cached values are the same 
            }
            //Debug.WriteLine("ParameterBindingsInvalid"); 
            return true; 
        }
 
        internal void CleanupBindings() {
            RowBinding rowBinding = this.RowBinding();
            if (null != rowBinding) {
                rowBinding.ResetValues(); 

                ColumnBinding[] columnBindings = this.ColumnBindings(); 
                for(int i = 0; i < columnBindings.Length; ++i) { 
                    ColumnBinding binding = columnBindings[i];
                    if (null != binding) { 
                        binding.ResetValue();
                    }
                }
            } 
        }
 
        internal void CloseFromConnection() { 
            if (null != _rowBinding) {
                _rowBinding.CloseFromConnection(); 
            }
            Dispose();
        }
 
        internal OleDbHResult CreateAccessor(UnsafeNativeMethods.IAccessor iaccessor, int flags) {
            Debug.Assert(null != _rowBinding, "no row binding"); 
            Debug.Assert(null != _columnBindings, "no column bindings"); 
            return _rowBinding.CreateAccessor(iaccessor, flags, _columnBindings);
        } 

        public void Dispose() {
            _parameters = null;
            _dataReader = null; 
            _columnBindings = null;
 
            RowBinding rowBinding = _rowBinding; 
            _rowBinding = null;
            if (null != rowBinding) { 
                rowBinding.Dispose();
            }
        }
 
        internal void GuidKindName(Guid guid, int eKind, IntPtr propid) {
            tagDBCOLUMNACCESS[] dbcolumns = DBColumnAccess; 
            dbcolumns[_index].columnid.uGuid = guid; 
            dbcolumns[_index].columnid.eKind = eKind;
            dbcolumns[_index].columnid.ulPropid = propid; 
        }

        internal void ParameterStatus(StringBuilder builder) {
            ColumnBinding[] columnBindings = ColumnBindings(); 
            for(int i = 0; i < columnBindings.Length; ++i) {
                ODB.CommandParameterStatus(builder, i, columnBindings[i].StatusValue()); 
            } 
        }
    } 
}


// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

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