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//------------------------------------------------------------------------------
// <copyright file="RecordManager.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
// <owner current="true" primary="true">[....]</owner>
// <owner current="true" primary="false">[....]</owner>
//------------------------------------------------------------------------------
namespace System.Data {
using System;
using System.Collections.Generic;
using System.Diagnostics;
internal sealed class RecordManager {
private readonly DataTable table;
private int lastFreeRecord;
private int minimumCapacity = 50;
private int recordCapacity = 0;
private readonly List<int> freeRecordList = new List<int>();
DataRow[] rows;
internal RecordManager(DataTable table) {
if (table == null) {
throw ExceptionBuilder.ArgumentNull("table");
}
this.table = table;
}
private void GrowRecordCapacity() {
if (NewCapacity(recordCapacity) < NormalizedMinimumCapacity(minimumCapacity))
RecordCapacity = NormalizedMinimumCapacity(minimumCapacity);
else
RecordCapacity = NewCapacity(recordCapacity);
// set up internal map : record --> row
DataRow[] newRows = table.NewRowArray(recordCapacity);
if (rows != null) {
Array.Copy(rows, 0, newRows, 0, Math.Min(lastFreeRecord, rows.Length));
}
rows = newRows;
}
internal int LastFreeRecord {
get { return lastFreeRecord; }
}
internal int MinimumCapacity {
get {
return minimumCapacity;
}
set {
if (minimumCapacity != value) {
if (value < 0) {
throw ExceptionBuilder.NegativeMinimumCapacity();
}
minimumCapacity = value;
}
}
}
internal int RecordCapacity {
get {
return recordCapacity;
}
set {
if (recordCapacity != value) {
for (int i = 0; i < table.Columns.Count; i++) {
table.Columns[i].SetCapacity(value);
}
recordCapacity = value;
}
}
}
internal static int NewCapacity(int capacity) {
return (capacity < 128) ? 128 : (capacity + capacity);
}
// Normalization: 64, 256, 1024, 2k, 3k, ....
private int NormalizedMinimumCapacity(int capacity) {
if (capacity < 1024 - 10) {
if (capacity < 256 - 10) {
if ( capacity < 54 )
return 64;
return 256;
}
return 1024;
}
return (((capacity + 10) >> 10) + 1) << 10;
}
internal int NewRecordBase() {
int record;
if (freeRecordList.Count != 0) {
record = freeRecordList[freeRecordList.Count - 1];
freeRecordList.RemoveAt(freeRecordList.Count - 1);
}
else {
if (lastFreeRecord >= recordCapacity) {
GrowRecordCapacity();
}
record = lastFreeRecord;
lastFreeRecord++;
}
Debug.Assert(record >=0 && record < recordCapacity, "NewRecord: Invalid record");
return record;
}
internal void FreeRecord(ref int record) {
Debug.Assert(-1 <= record && record < recordCapacity, "invalid record");
// Debug.Assert(record < lastFreeRecord, "Attempt to Free() <outofbounds> record");
if (-1 != record) {
this[record] = null;
int count = table.columnCollection.Count;
for(int i = 0; i < count; ++i) {
table.columnCollection[i].FreeRecord(record);
}
// if freeing the last record, recycle it
if (lastFreeRecord == record + 1) {
lastFreeRecord--;
}
else if (record < lastFreeRecord) {
// Debug.Assert(-1 == freeRecordList.IndexOf(record), "Attempt to double Free() record");
freeRecordList.Add(record);
}
record = -1;
}
}
internal void Clear(bool clearAll) {
if (clearAll) {
for(int record = 0; record < recordCapacity; ++record) {
rows[record] = null;
}
int count = table.columnCollection.Count;
for(int i = 0; i < count; ++i) {
// SQLBU 415729: Serious performance issue when calling Clear()
// this improves performance by caching the column instead of obtaining it for each row
DataColumn column = table.columnCollection[i];
for(int record = 0; record < recordCapacity; ++record) {
column.FreeRecord(record);
}
}
lastFreeRecord = 0;
freeRecordList.Clear();
}
else { // just clear attached rows
freeRecordList.Capacity = freeRecordList.Count + table.Rows.Count;
for(int record = 0; record < recordCapacity; ++record) {
if (rows[record]!= null && rows[record].rowID != -1) {
int tempRecord = record;
FreeRecord(ref tempRecord);
}
}
}
}
internal DataRow this[int record] {
get {
Debug.Assert(record >= 0 && record < rows.Length, "Invalid record number");
return rows[record];
}
set {
Debug.Assert(record >= 0 && record < rows.Length, "Invalid record number");
rows[record] = value;
}
}
internal void SetKeyValues(int record, DataKey key, object[] keyValues) {
for (int i = 0; i < keyValues.Length; i++) {
key.ColumnsReference[i][record] = keyValues[i];
}
}
// Increases AutoIncrementCurrent
internal int ImportRecord(DataTable src, int record) {
return CopyRecord(src, record, -1);
}
// No impact on AutoIncrementCurrent if over written
internal int CopyRecord(DataTable src, int record, int copy) {
Debug.Assert(src != null, "Can not Merge record without a table");
if (record == -1) {
return copy;
}
int newRecord = -1;
try {
if (copy == -1) {
newRecord = table.NewUninitializedRecord();
}
else {
newRecord = copy;
}
int count = table.Columns.Count;
for (int i = 0; i < count; ++i) {
DataColumn dstColumn = table.Columns[i];
DataColumn srcColumn = src.Columns[dstColumn.ColumnName];
if (null != srcColumn) {
object value = srcColumn[record];
ICloneable cloneableObject = value as ICloneable;
if (null != cloneableObject) {
dstColumn[newRecord] = cloneableObject.Clone();
}
else {
dstColumn[newRecord] = value;
}
}
else if (-1 == copy) {
dstColumn.Init(newRecord);
}
}
}
catch (Exception e){
//
if (Common.ADP.IsCatchableOrSecurityExceptionType(e)) {
if (-1 == copy) {
FreeRecord(ref newRecord);
}
}
throw;
}
return newRecord;
}
internal void SetRowCache(DataRow[] newRows) {
rows = newRows;
lastFreeRecord = rows.Length;
recordCapacity = lastFreeRecord;
}
[Conditional("DEBUG")]
internal void VerifyRecord(int record) {
Debug.Assert((record < lastFreeRecord) && (-1 == freeRecordList.IndexOf(record)), "accesing free record");
Debug.Assert((null == rows[record]) ||
(record == rows[record].oldRecord) ||
(record == rows[record].newRecord) ||
(record == rows[record].tempRecord), "record of a different row");
}
[Conditional("DEBUG")]
internal void VerifyRecord(int record, DataRow row) {
Debug.Assert((record < lastFreeRecord) && (-1 == freeRecordList.IndexOf(record)), "accesing free record");
Debug.Assert((null == rows[record]) || (row == rows[record]), "record of a different row");
}
}
}
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