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//------------------------------------------------------------------------------
// <copyright file="DataTableReader.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>
// <owner current="false" primary="false">Microsoft</owner>
//------------------------------------------------------------------------------
namespace System.Data {
using System;
using System.Data.Common;
using System.Data.SqlTypes;
using System.Collections;
using System.ComponentModel;
public sealed class DataTableReader : DbDataReader {
private readonly DataTable[] tables = null;
private bool isOpen = true;
private DataTable schemaTable = null;
private int tableCounter = -1;
private int rowCounter = -1;
private DataTable currentDataTable = null;
private DataRow currentDataRow = null;
private bool hasRows= true;
private bool reachEORows = false;
private bool currentRowRemoved = false;
private bool schemaIsChanged = false;
private bool started = false;
private bool readerIsInvalid = false;
private DataTableReaderListener listener = null;
private bool tableCleared = false;
public DataTableReader(DataTable dataTable) {
if (dataTable == null)
throw ExceptionBuilder.ArgumentNull("DataTable");
tables = new DataTable[1] {dataTable};
init();
// schemaTable = GetSchemaTableFromDataTable(currentDataTable);
}
public DataTableReader(DataTable [] dataTables) {
if (dataTables == null)
throw ExceptionBuilder.ArgumentNull("DataTable");
if (dataTables.Length == 0)
throw ExceptionBuilder.DataTableReaderArgumentIsEmpty();
tables = new DataTable[dataTables.Length];
for (int i = 0; i < dataTables.Length ; i++) {
if (dataTables[i] == null)
throw ExceptionBuilder.ArgumentNull("DataTable");
tables[i] = dataTables[i];
}
init();
// schemaTable = GetSchemaTableFromDataTable(currentDataTable);
}
private bool ReaderIsInvalid {
get {
return readerIsInvalid;
}
set {
if (readerIsInvalid == value)
return;
readerIsInvalid = value;
if (readerIsInvalid && listener != null) {
listener.CleanUp();
}
}
}
private bool IsSchemaChanged {
get {
return schemaIsChanged;
}
set {
if (!value || schemaIsChanged == value) //once it is set to false; should not change unless in init() or NextResult()
return;
schemaIsChanged = value;
if (listener != null) {
listener.CleanUp();
}
}
}
internal DataTable CurrentDataTable {
get {
return currentDataTable;
}
}
private void init() {
tableCounter = 0;
reachEORows = false;
schemaIsChanged = false;
currentDataTable = tables[tableCounter];
hasRows = (currentDataTable.Rows.Count > 0);
ReaderIsInvalid = false;
// we need to listen to current tables event so create a listener, it will listen to events and call us back.
listener = new DataTableReaderListener(this);
}
override public void Close() {
if (!isOpen)
return;
// no need to listen to events after close
if (listener != null)
listener.CleanUp();
listener = null;
schemaTable = null;
isOpen = false;
}
override public DataTable GetSchemaTable(){
ValidateOpen("GetSchemaTable");
ValidateReader();
// each time, we just get schema table of current table for once, no need to recreate each time, if schema is changed, reader is already
// is invalid
if (schemaTable == null)
schemaTable = GetSchemaTableFromDataTable(currentDataTable);
return schemaTable;
}
override public bool NextResult() {
// next result set; reset everything
ValidateOpen("NextResult");
if ((tableCounter == tables.Length -1))
return false;
currentDataTable = tables[++tableCounter];
if (listener != null)
listener.UpdataTable(currentDataTable); // it will unsubscribe from preveous tables events and subscribe to new table's events
schemaTable = null;
rowCounter = -1;
currentRowRemoved = false;
reachEORows = false;
schemaIsChanged = false;
started = false;
ReaderIsInvalid = false;
tableCleared = false;
hasRows = (currentDataTable.Rows.Count > 0);
return true;
}
override public bool Read() {
/* else if (tableCleared) {
return false;
throw ExceptionBuilder.EmptyDataTableReader(currentDataTable.TableName);
}
*/
if (!started) {
started = true;
}
/*else {
ValidateRow(rowCounter);
}*/
ValidateOpen("Read");
ValidateReader();
if(reachEORows) {
return false;
}
if (rowCounter >= currentDataTable.Rows.Count -1 ) {
reachEORows = true;
if (listener != null)
listener.CleanUp();
return false;
}
rowCounter ++;
ValidateRow(rowCounter);
currentDataRow = currentDataTable.Rows[rowCounter];
while (currentDataRow.RowState == DataRowState.Deleted) {
rowCounter++;
if (rowCounter == currentDataTable.Rows.Count) {
reachEORows = true;
if (listener != null)
listener.CleanUp();
return false;
}
ValidateRow(rowCounter);
currentDataRow = currentDataTable.Rows[rowCounter];
}
if (currentRowRemoved)
currentRowRemoved = false;
return true;
}
override public int Depth {
get {
ValidateOpen("Depth");
ValidateReader();
return 0;
}
}
override public bool IsClosed {
get {
return (!isOpen);
}
}
override public int RecordsAffected {
get {
ValidateReader();
return 0;
}
}
override public bool HasRows {
get {
ValidateOpen("HasRows");
ValidateReader();
return hasRows;
}
}
override public object this[int ordinal] {
get {
ValidateOpen("Item");
ValidateReader();
if ((currentDataRow == null) || (currentDataRow.RowState == DataRowState.Deleted)) {
ReaderIsInvalid = true;
throw ExceptionBuilder.InvalidDataTableReader(currentDataTable.TableName);
}
try {
return currentDataRow[ordinal];
}
catch(IndexOutOfRangeException e) { // thrown by DataColumnCollection
ExceptionBuilder.TraceExceptionWithoutRethrow(e);
throw ExceptionBuilder.ArgumentOutOfRange("ordinal");
}
}
}
override public object this[string name] {
get {
ValidateOpen("Item");
ValidateReader();
if ((currentDataRow == null) || (currentDataRow.RowState == DataRowState.Deleted)) {
ReaderIsInvalid = true;
throw ExceptionBuilder.InvalidDataTableReader(currentDataTable.TableName);
}
return currentDataRow[name];
}
}
override public Int32 FieldCount {
get {
ValidateOpen("FieldCount");
ValidateReader();
return currentDataTable.Columns.Count;
}
}
override public Type GetProviderSpecificFieldType(int ordinal) {
ValidateOpen("GetProviderSpecificFieldType");
ValidateReader();
return GetFieldType(ordinal);
}
override public Object GetProviderSpecificValue(int ordinal) {
ValidateOpen("GetProviderSpecificValue");
ValidateReader();
return GetValue(ordinal);
}
override public int GetProviderSpecificValues(object[] values) {
ValidateOpen("GetProviderSpecificValues");
ValidateReader();
return GetValues(values);
}
override public bool GetBoolean (int ordinal) {
ValidateState("GetBoolean");
ValidateReader();
try {
return (bool) currentDataRow[ordinal];
}
catch(IndexOutOfRangeException e) { // thrown by DataColumnCollection
ExceptionBuilder.TraceExceptionWithoutRethrow(e);
throw ExceptionBuilder.ArgumentOutOfRange("ordinal");
}
}
override public byte GetByte (int ordinal) {
ValidateState("GetByte");
ValidateReader();
try {
return (byte) currentDataRow[ordinal];
}
catch(IndexOutOfRangeException e) { // thrown by DataColumnCollection
ExceptionBuilder.TraceExceptionWithoutRethrow(e);
throw ExceptionBuilder.ArgumentOutOfRange("ordinal");
}
}
override public long GetBytes(int ordinal, long dataIndex, byte[] buffer, int bufferIndex, int length) {
ValidateState("GetBytes");
ValidateReader();
byte[] tempBuffer;
try {
tempBuffer = (byte[]) currentDataRow[ordinal];
}
catch(IndexOutOfRangeException e) { // thrown by DataColumnCollection
ExceptionBuilder.TraceExceptionWithoutRethrow(e);
throw ExceptionBuilder.ArgumentOutOfRange("ordinal");
}
if (buffer == null) {
return tempBuffer.Length;
}
int srcIndex = (int) dataIndex;
int byteCount = Math.Min(tempBuffer.Length - srcIndex, length);
if (srcIndex < 0) {
throw ADP.InvalidSourceBufferIndex(tempBuffer.Length, srcIndex, "dataIndex");
}
else if ((bufferIndex < 0) || (bufferIndex > 0 && bufferIndex >= buffer.Length)) {
throw ADP.InvalidDestinationBufferIndex(buffer.Length, bufferIndex, "bufferIndex");
}
if (0 < byteCount) {
Array.Copy(tempBuffer, dataIndex, buffer, bufferIndex, byteCount);
}
else if (length < 0) {
throw ADP.InvalidDataLength(length);
}
else {
byteCount = 0;
}
return byteCount;
}
override public char GetChar (int ordinal) {
ValidateState("GetChar");
ValidateReader();
try {
return (char) currentDataRow[ordinal];
}
catch(IndexOutOfRangeException e) { // thrown by DataColumnCollection
ExceptionBuilder.TraceExceptionWithoutRethrow(e);
throw ExceptionBuilder.ArgumentOutOfRange("ordinal");
}
}
override public long GetChars(int ordinal, long dataIndex, char[] buffer, int bufferIndex, int length) {
ValidateState("GetChars");
ValidateReader();
char[] tempBuffer;
try {
tempBuffer = (char[]) currentDataRow[ordinal];
}
catch(IndexOutOfRangeException e) { // thrown by DataColumnCollection
ExceptionBuilder.TraceExceptionWithoutRethrow(e);
throw ExceptionBuilder.ArgumentOutOfRange("ordinal");
}
if (buffer == null) {
return tempBuffer.Length;
}
int srcIndex = (int) dataIndex;
int charCount = Math.Min(tempBuffer.Length - srcIndex, length);
if (srcIndex < 0) {
throw ADP.InvalidSourceBufferIndex(tempBuffer.Length, srcIndex, "dataIndex");
}
else if ((bufferIndex < 0) || (bufferIndex > 0 && bufferIndex >= buffer.Length)) {
throw ADP.InvalidDestinationBufferIndex(buffer.Length, bufferIndex, "bufferIndex");
}
if (0 < charCount) {
Array.Copy(tempBuffer, dataIndex, buffer, bufferIndex, charCount);
}
else if (length < 0) {
throw ADP.InvalidDataLength(length);
}
else {
charCount = 0;
}
return charCount;
}
override public String GetDataTypeName (int ordinal) {
ValidateOpen("GetDataTypeName");
ValidateReader();
return ((Type)GetFieldType(ordinal)).Name;
}
override public DateTime GetDateTime (int ordinal) {
ValidateState("GetDateTime");
ValidateReader();
try {
return (DateTime) currentDataRow[ordinal];
}
catch(IndexOutOfRangeException e) { // thrown by DataColumnCollection
ExceptionBuilder.TraceExceptionWithoutRethrow(e);
throw ExceptionBuilder.ArgumentOutOfRange("ordinal");
}
}
override public Decimal GetDecimal (int ordinal) {
ValidateState("GetDecimal");
ValidateReader();
try {
return (Decimal) currentDataRow[ordinal];
}
catch(IndexOutOfRangeException e) { // thrown by DataColumnCollection
ExceptionBuilder.TraceExceptionWithoutRethrow(e);
throw ExceptionBuilder.ArgumentOutOfRange("ordinal");
}
}
override public Double GetDouble (int ordinal) {
ValidateState("GetDouble");
ValidateReader();
try {
return (double) currentDataRow[ordinal];
}
catch(IndexOutOfRangeException e) { // thrown by DataColumnCollection
ExceptionBuilder.TraceExceptionWithoutRethrow(e);
throw ExceptionBuilder.ArgumentOutOfRange("ordinal");
}
}
override public Type GetFieldType (int ordinal) {
ValidateOpen("GetFieldType");
ValidateReader();
try {
return (currentDataTable.Columns[ordinal].DataType);
}
catch(IndexOutOfRangeException e) { // thrown by DataColumnCollection
ExceptionBuilder.TraceExceptionWithoutRethrow(e);
throw ExceptionBuilder.ArgumentOutOfRange("ordinal");
}
}
override public Single GetFloat (int ordinal) {
ValidateState("GetFloat");
ValidateReader();
try {
return (Single) currentDataRow[ordinal];
}
catch(IndexOutOfRangeException e) { // thrown by DataColumnCollection
ExceptionBuilder.TraceExceptionWithoutRethrow(e);
throw ExceptionBuilder.ArgumentOutOfRange("ordinal");
}
}
override public Guid GetGuid (int ordinal) {
ValidateState("GetGuid");
ValidateReader();
try {
return (Guid) currentDataRow[ordinal];
}
catch(IndexOutOfRangeException e) { // thrown by DataColumnCollection
ExceptionBuilder.TraceExceptionWithoutRethrow(e);
throw ExceptionBuilder.ArgumentOutOfRange("ordinal");
}
}
override public Int16 GetInt16 (int ordinal) {
ValidateState("GetInt16");
ValidateReader();
try {
return (Int16) currentDataRow[ordinal];
}
catch(IndexOutOfRangeException e) { // thrown by DataColumnCollection
ExceptionBuilder.TraceExceptionWithoutRethrow(e);
throw ExceptionBuilder.ArgumentOutOfRange("ordinal");
}
}
override public Int32 GetInt32 (int ordinal) {
ValidateState("GetInt32");
ValidateReader();
try {
return (Int32) currentDataRow[ordinal];
}
catch(IndexOutOfRangeException e) { // thrown by DataColumnCollection
ExceptionBuilder.TraceExceptionWithoutRethrow(e);
throw ExceptionBuilder.ArgumentOutOfRange("ordinal");
}
}
override public Int64 GetInt64 (int ordinal) {
ValidateState("GetInt64");
ValidateReader();
try {
return (Int64) currentDataRow[ordinal];
}
catch(IndexOutOfRangeException e) { // thrown by DataColumnCollection
ExceptionBuilder.TraceExceptionWithoutRethrow(e);
throw ExceptionBuilder.ArgumentOutOfRange("ordinal");
}
}
override public String GetName (int ordinal) {
ValidateOpen("GetName");
ValidateReader();
try {
return (currentDataTable.Columns[ordinal].ColumnName);
}
catch(IndexOutOfRangeException e) { // thrown by DataColumnCollection
ExceptionBuilder.TraceExceptionWithoutRethrow(e);
throw ExceptionBuilder.ArgumentOutOfRange("ordinal");
}
}
override public Int32 GetOrdinal (string name) {
ValidateOpen("GetOrdinal");
ValidateReader();
DataColumn dc = currentDataTable.Columns[name];
if (dc != null) {
return dc.Ordinal;// WebData 113248
}
else{
throw ExceptionBuilder.ColumnNotInTheTable(name, currentDataTable.TableName);
}
}
override public string GetString (int ordinal) {
ValidateState("GetString");
ValidateReader();
try {
return (string) currentDataRow[ordinal];
}
catch(IndexOutOfRangeException e) { // thrown by DataColumnCollection
ExceptionBuilder.TraceExceptionWithoutRethrow(e);
throw ExceptionBuilder.ArgumentOutOfRange("ordinal");
}
}
override public object GetValue (int ordinal) {
ValidateState("GetValue");
ValidateReader();
try {
return currentDataRow[ordinal];
}
catch(IndexOutOfRangeException e) { // thrown by DataColumnCollection
ExceptionBuilder.TraceExceptionWithoutRethrow(e);
throw ExceptionBuilder.ArgumentOutOfRange("ordinal");
}
}
override public Int32 GetValues (object[] values) {
ValidateState("GetValues");
ValidateReader();
if (values ==null)
throw ExceptionBuilder.ArgumentNull("values");
Array.Copy(currentDataRow.ItemArray, values, currentDataRow.ItemArray.Length > values.Length ? values.Length : currentDataRow.ItemArray.Length);
return (currentDataRow.ItemArray.Length > values.Length ? values.Length : currentDataRow.ItemArray.Length);
}
override public bool IsDBNull (int ordinal) {
ValidateState("IsDBNull");
ValidateReader();
try {
return (currentDataRow.IsNull(ordinal));
}
catch(IndexOutOfRangeException e) { // thrown by DataColumnCollection
ExceptionBuilder.TraceExceptionWithoutRethrow(e);
throw ExceptionBuilder.ArgumentOutOfRange("ordinal");
}
}
// IEnumerable
override public IEnumerator GetEnumerator() {
ValidateOpen("GetEnumerator");
return new DbEnumerator((IDataReader)this);
}
static internal DataTable GetSchemaTableFromDataTable(DataTable table) {
if (table == null) {
throw ExceptionBuilder.ArgumentNull("DataTable");
}
DataTable tempSchemaTable = new DataTable("SchemaTable");
tempSchemaTable.Locale = System.Globalization.CultureInfo.InvariantCulture;
DataColumn ColumnName = new DataColumn(SchemaTableColumn.ColumnName, typeof(System.String));
DataColumn ColumnOrdinal = new DataColumn(SchemaTableColumn.ColumnOrdinal, typeof(System.Int32));
DataColumn ColumnSize = new DataColumn(SchemaTableColumn.ColumnSize, typeof(System.Int32));
DataColumn NumericPrecision = new DataColumn(SchemaTableColumn.NumericPrecision, typeof(System.Int16));
DataColumn NumericScale = new DataColumn(SchemaTableColumn.NumericScale, typeof(System.Int16));
DataColumn DataType = new DataColumn(SchemaTableColumn.DataType, typeof(System.Type));
DataColumn ProviderType = new DataColumn(SchemaTableColumn.ProviderType, typeof(System.Int32));
DataColumn IsLong = new DataColumn(SchemaTableColumn.IsLong, typeof(System.Boolean));
DataColumn AllowDBNull = new DataColumn(SchemaTableColumn.AllowDBNull, typeof(System.Boolean));
DataColumn IsReadOnly = new DataColumn(SchemaTableOptionalColumn.IsReadOnly, typeof(System.Boolean));
DataColumn IsRowVersion = new DataColumn(SchemaTableOptionalColumn.IsRowVersion, typeof(System.Boolean));
DataColumn IsUnique = new DataColumn(SchemaTableColumn.IsUnique, typeof(System.Boolean));
DataColumn IsKeyColumn = new DataColumn(SchemaTableColumn.IsKey, typeof(System.Boolean));
DataColumn IsAutoIncrement = new DataColumn(SchemaTableOptionalColumn.IsAutoIncrement, typeof(System.Boolean));
DataColumn BaseSchemaName = new DataColumn(SchemaTableColumn.BaseSchemaName, typeof(System.String));
DataColumn BaseCatalogName = new DataColumn(SchemaTableOptionalColumn.BaseCatalogName, typeof(System.String));
DataColumn BaseTableName = new DataColumn(SchemaTableColumn.BaseTableName, typeof(System.String));
DataColumn BaseColumnName = new DataColumn(SchemaTableColumn.BaseColumnName, typeof(System.String));
DataColumn AutoIncrementSeed = new DataColumn(SchemaTableOptionalColumn.AutoIncrementSeed, typeof(System.Int64));
DataColumn AutoIncrementStep = new DataColumn(SchemaTableOptionalColumn.AutoIncrementStep, typeof(System.Int64));
DataColumn DefaultValue = new DataColumn(SchemaTableOptionalColumn.DefaultValue, typeof(System.Object));
DataColumn Expression = new DataColumn(SchemaTableOptionalColumn.Expression, typeof(System.String));
DataColumn ColumnMapping = new DataColumn(SchemaTableOptionalColumn.ColumnMapping, typeof(System.Data.MappingType));
DataColumn BaseTableNamespace = new DataColumn(SchemaTableOptionalColumn.BaseTableNamespace, typeof(System.String));
DataColumn BaseColumnNamespace = new DataColumn(SchemaTableOptionalColumn.BaseColumnNamespace, typeof(System.String));
ColumnSize.DefaultValue = -1;
if (table.DataSet != null)
BaseCatalogName.DefaultValue = table.DataSet.DataSetName;
BaseTableName.DefaultValue = table.TableName;
BaseTableNamespace.DefaultValue = table.Namespace;
IsRowVersion.DefaultValue = false;
IsLong.DefaultValue = false;
IsReadOnly.DefaultValue = false;
IsKeyColumn.DefaultValue = false;
IsAutoIncrement.DefaultValue = false;
AutoIncrementSeed.DefaultValue = 0;
AutoIncrementStep.DefaultValue = 1;
tempSchemaTable.Columns.Add(ColumnName);
tempSchemaTable.Columns.Add(ColumnOrdinal);
tempSchemaTable.Columns.Add(ColumnSize);
tempSchemaTable.Columns.Add(NumericPrecision);
tempSchemaTable.Columns.Add(NumericScale);
tempSchemaTable.Columns.Add(DataType);
tempSchemaTable.Columns.Add(ProviderType);
tempSchemaTable.Columns.Add(IsLong);
tempSchemaTable.Columns.Add(AllowDBNull);
tempSchemaTable.Columns.Add(IsReadOnly);
tempSchemaTable.Columns.Add(IsRowVersion);
tempSchemaTable.Columns.Add(IsUnique);
tempSchemaTable.Columns.Add(IsKeyColumn);
tempSchemaTable.Columns.Add(IsAutoIncrement);
tempSchemaTable.Columns.Add(BaseCatalogName);
tempSchemaTable.Columns.Add(BaseSchemaName);
// specific to datatablereader
tempSchemaTable.Columns.Add(BaseTableName);
tempSchemaTable.Columns.Add(BaseColumnName);
tempSchemaTable.Columns.Add(AutoIncrementSeed);
tempSchemaTable.Columns.Add(AutoIncrementStep);
tempSchemaTable.Columns.Add(DefaultValue);
tempSchemaTable.Columns.Add(Expression);
tempSchemaTable.Columns.Add(ColumnMapping);
tempSchemaTable.Columns.Add(BaseTableNamespace);
tempSchemaTable.Columns.Add(BaseColumnNamespace);
foreach (DataColumn dc in table.Columns) {
DataRow dr = tempSchemaTable.NewRow();
dr[ColumnName] = dc.ColumnName;
dr[ColumnOrdinal] = dc.Ordinal;
dr[DataType] = dc.DataType;
if (dc.DataType == typeof(string)) {
dr[ColumnSize] = dc.MaxLength;
}
dr[AllowDBNull] = dc.AllowDBNull;
dr[IsReadOnly] = dc.ReadOnly;
dr[IsUnique] = dc.Unique;
if (dc.AutoIncrement) {
dr[IsAutoIncrement] = true;
dr[AutoIncrementSeed] = dc.AutoIncrementSeed;
dr[AutoIncrementStep] = dc.AutoIncrementStep;
}
if (dc.DefaultValue != DBNull.Value)
dr[DefaultValue] = dc.DefaultValue;
if (dc.Expression.Length != 0) {
bool hasExternalDependency = false;
DataColumn[] dependency = dc.DataExpression.GetDependency();
for (int j = 0; j < dependency.Length; j++) {
if (dependency[j].Table != table) {
hasExternalDependency = true;
break;
}
}
if (!hasExternalDependency)
dr[Expression] = dc.Expression;
}
dr[ColumnMapping] = dc.ColumnMapping;
dr[BaseColumnName] = dc.ColumnName;
dr[BaseColumnNamespace] = dc.Namespace;
tempSchemaTable.Rows.Add(dr);
}
foreach(DataColumn key in table.PrimaryKey) {
tempSchemaTable.Rows[key.Ordinal][IsKeyColumn] = true;
}
tempSchemaTable.AcceptChanges();
return tempSchemaTable;
}
private void ValidateOpen(string caller) {
if (!isOpen)
throw ADP.DataReaderClosed(caller);
}
private void ValidateReader() {
if (ReaderIsInvalid)
throw ExceptionBuilder.InvalidDataTableReader(currentDataTable.TableName);
if (IsSchemaChanged) {
throw ExceptionBuilder.DataTableReaderSchemaIsInvalid(currentDataTable.TableName); // may be we can use better error message!
}
}
private void ValidateState(string caller) {
ValidateOpen(caller);
if (tableCleared) {
throw ExceptionBuilder.EmptyDataTableReader(currentDataTable.TableName);
}
// see if without any event raising, if our curent row has some changes!if so reader is invalid.
if ((currentDataRow == null) || (currentDataTable == null) ) {//|| (currentDataRow != currentDataTable.Rows[rowCounter])) do we need thios check!
ReaderIsInvalid = true;
throw ExceptionBuilder.InvalidDataTableReader(currentDataTable.TableName);
}
//See if without any event raing, if our rows are deleted, or removed! Reader is not invalid, user should be able to read and reach goo row WebData98325
if ((currentDataRow.RowState == DataRowState.Deleted) || (currentDataRow.RowState == DataRowState.Detached) ||currentRowRemoved)
throw ExceptionBuilder.InvalidCurrentRowInDataTableReader();
// user may have called clear (which removes the rows without raing event) or deleted part of rows without raising event!if so reader is invalid.
if (0 > rowCounter ||currentDataTable.Rows.Count <= rowCounter) {
ReaderIsInvalid = true;
throw ExceptionBuilder.InvalidDataTableReader(currentDataTable.TableName);
}
else {
}
}
private void ValidateRow(Int32 rowPosition) {
if (ReaderIsInvalid)
throw ExceptionBuilder.InvalidDataTableReader(currentDataTable.TableName);
if (0 > rowPosition ||currentDataTable.Rows.Count <= rowPosition) {
ReaderIsInvalid = true;
throw ExceptionBuilder.InvalidDataTableReader(currentDataTable.TableName);
}
}
// Event Call backs from DataTableReaderListener, will invoke these methods
internal void SchemaChanged() {
IsSchemaChanged = true;
}
internal void DataTableCleared() {
if (!started)
return;
rowCounter = -1;
if (!reachEORows)
currentRowRemoved = true;
}
internal void DataChanged(DataRowChangeEventArgs args ) {
if ((!started) ||(rowCounter == -1 && !tableCleared))
return;
/* if (rowCounter == -1 && tableCleared && args.Action == DataRowAction.Add) {
tableCleared = false;
return;
}
*/
switch (args.Action) {
case DataRowAction.Add:
ValidateRow(rowCounter + 1);
/* if (tableCleared) {
tableCleared = false;
rowCounter++;
currentDataRow = currentDataTable.Rows[rowCounter];
currentRowRemoved = false;
}
else
*/
if (currentDataRow == currentDataTable.Rows[rowCounter + 1]) { // check if we moved one position up
rowCounter++; // if so, refresh the datarow and fix the counter
}
break;
case DataRowAction.Delete: // delete
case DataRowAction.Rollback:// rejectchanges
case DataRowAction.Commit: // acceptchanges
if ( args.Row.RowState == DataRowState.Detached ) {
if (args.Row != currentDataRow) {
if (rowCounter == 0) // if I am at first row and no previous row exist,NOOP
break;
ValidateRow(rowCounter -1);
if (currentDataRow == currentDataTable.Rows[rowCounter - 1]) { // one of previous rows is detached, collection size is changed!
rowCounter--;
}
}
else { // we are proccessing current datarow
currentRowRemoved = true;
if (rowCounter > 0) { // go back one row, no matter what the state is
rowCounter--;
currentDataRow = currentDataTable.Rows[rowCounter];
}
else { // we are on 0th row, so reset data to initial state!
rowCounter = -1;
currentDataRow = null;
}
}
}
break;
default:
break;
}
}
}
}
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