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//
// Copyright (C) 2004 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System;
using System.Collections;
namespace System.Data.Common
{
internal class RecordCache
{
#region Fields
const int MIN_CACHE_SIZE = 128;
Stack _records = new Stack(16);
int _nextFreeIndex = 0;
int _currentCapacity = 0;
DataTable _table;
DataRow[] _rowsToRecords;
#endregion // Fields
#region Constructors
internal RecordCache(DataTable table)
{
_table = table;
_rowsToRecords = table.NewRowArray(16);
}
#endregion //Constructors
#region Properties
internal int CurrentCapacity
{
get {
return _currentCapacity;
}
}
internal DataRow this[int index]
{
get {
return _rowsToRecords[index];
}
set {
if (index >= 0) {
_rowsToRecords[index] = value;
}
}
}
#endregion // Properties
#region Methods
internal int NewRecord()
{
if (_records.Count > 0) {
return (int)_records.Pop();
}
else {
DataColumnCollection cols = _table.Columns;
if (_nextFreeIndex >= _currentCapacity) {
_currentCapacity *= 2;
if ( _currentCapacity < MIN_CACHE_SIZE ) {
_currentCapacity = MIN_CACHE_SIZE;
}
foreach(DataColumn col in cols) {
col.DataContainer.Capacity = _currentCapacity;
}
DataRow[] old = _rowsToRecords;
_rowsToRecords = _table.NewRowArray(_currentCapacity);
Array.Copy(old,0,_rowsToRecords,0,old.Length);
}
return _nextFreeIndex++;
}
}
internal void DisposeRecord(int index)
{
if ( index < 0 ) {
throw new ArgumentException();
}
if (!_records.Contains (index))
_records.Push(index);
this[index] = null;
}
internal int CopyRecord(DataTable fromTable,int fromRecordIndex,int toRecordIndex)
{
int recordIndex = toRecordIndex;
if (toRecordIndex == -1) {
recordIndex = NewRecord();
}
try
{
foreach(DataColumn fromColumn in fromTable.Columns)
{
DataColumn column = _table.Columns[fromColumn.ColumnName];
if (column != null)
{
column.DataContainer.CopyValue(fromColumn.DataContainer,fromRecordIndex,recordIndex);
}
}
return recordIndex;
}
catch
{
if (toRecordIndex == -1)
DisposeRecord(recordIndex);
throw;
}
}
internal void ReadIDataRecord(int recordIndex, IDataRecord record, int[] mapping, int length)
{
if ( mapping.Length > _table.Columns.Count)
throw new ArgumentException ();
int i=0;
for(; i < length; i++) {
DataColumn column = _table.Columns[mapping[i]];
column.DataContainer.SetItemFromDataRecord(recordIndex, record,i);
}
for (; i < mapping.Length; i++)
{
DataColumn column = _table.Columns[mapping[i]];
if ( column.AutoIncrement )
column.DataContainer[recordIndex] = column.AutoIncrementValue ();
else
column.DataContainer[recordIndex] = column.DefaultValue;
}
}
#endregion // Methods
}
}
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