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//------------------------------------------------------------------------------
// <copyright file="SqlDataSourceEnumerator.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>
//------------------------------------------------------------------------------
namespace System.Data.Sql {
using System;
using System.Data;
using System.Data.Common;
using System.Data.SqlClient;
using System.Diagnostics;
using System.Globalization;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Security;
using System.Text;
public sealed class SqlDataSourceEnumerator : DbDataSourceEnumerator {
private static readonly SqlDataSourceEnumerator SingletonInstance = new SqlDataSourceEnumerator();
internal const string ServerName = "ServerName";
internal const string InstanceName = "InstanceName";
internal const string IsClustered = "IsClustered";
internal const string Version = "Version";
private const int timeoutSeconds = ADP.DefaultCommandTimeout;
private long timeoutTime; // variable used for timeout computations, holds the value of the hi-res performance counter at which this request should expire
private SqlDataSourceEnumerator() : base() {
}
public static SqlDataSourceEnumerator Instance {
get {
return SqlDataSourceEnumerator.SingletonInstance;
}
}
override public DataTable GetDataSources() {
(new NamedPermissionSet("FullTrust")).Demand(); // SQLBUDT 244304
char[] buffer = null;
StringBuilder strbldr = new StringBuilder();
Int32 bufferSize = 1024;
Int32 readLength = 0;
buffer = new char[bufferSize];
bool more = true;
bool failure = false;
IntPtr handle = ADP.PtrZero;
RuntimeHelpers.PrepareConstrainedRegions();
try {
timeoutTime = TdsParserStaticMethods.GetTimeoutSeconds(timeoutSeconds);
RuntimeHelpers.PrepareConstrainedRegions();
try {} finally {
handle = SNINativeMethodWrapper.SNIServerEnumOpen();
}
if (ADP.PtrZero != handle) {
while (more && !TdsParserStaticMethods.TimeoutHasExpired(timeoutTime)) {
readLength = SNINativeMethodWrapper.SNIServerEnumRead(handle, buffer, bufferSize, ref more);
if (readLength > bufferSize) {
failure = true;
more = false;
}
else if (0 < readLength) {
strbldr.Append(buffer, 0, readLength);
}
}
}
}
finally {
if (ADP.PtrZero != handle) {
SNINativeMethodWrapper.SNIServerEnumClose(handle);
}
}
if (failure) {
Debug.Assert(false, "GetDataSources:SNIServerEnumRead returned bad length");
Bid.Trace("<sc.SqlDataSourceEnumerator.GetDataSources|ERR> GetDataSources:SNIServerEnumRead returned bad length, requested %d, received %d", bufferSize, readLength);
throw ADP.ArgumentOutOfRange("readLength");
}
return ParseServerEnumString(strbldr.ToString());
}
private static string _Version = "Version:";
private static string _Cluster = "Clustered:";
private static int _clusterLength = _Cluster.Length;
private static int _versionLength =_Version.Length;
static private DataTable ParseServerEnumString(string serverInstances) {
DataTable dataTable = new DataTable("SqlDataSources");
dataTable.Locale = CultureInfo.InvariantCulture;
dataTable.Columns.Add(ServerName, typeof(string));
dataTable.Columns.Add(InstanceName, typeof(string));
dataTable.Columns.Add(IsClustered, typeof(string));
dataTable.Columns.Add(Version, typeof(string));
DataRow dataRow = null;
string serverName = null;
string instanceName = null;
string isClustered = null;
string version = null;
// Every row comes in the format "serverName\instanceName;Clustered:[Yes|No];Version:.."
// Every row is terminated by a null character.
// Process one row at a time
foreach (string instance in serverInstances.Split('\0')) {
string value = instance.Trim('\0'); // MDAC 91934
if (0 == value.Length) {
continue;
}
foreach (string instance2 in value.Split(';')) {
if (serverName == null) {
foreach(string instance3 in instance2.Split('\\')) {
if (serverName == null) {
serverName = instance3;
continue;
}
Debug.Assert(instanceName == null);
instanceName = instance3;
}
continue;
}
if (isClustered == null) {
Debug.Assert(String.Compare(_Cluster, 0, instance2, 0, _clusterLength, StringComparison.OrdinalIgnoreCase) == 0);
isClustered = instance2.Substring(_clusterLength);
continue;
}
Debug.Assert(version == null);
Debug.Assert(String.Compare(_Version, 0, instance2, 0, _versionLength, StringComparison.OrdinalIgnoreCase) == 0);
version = instance2.Substring(_versionLength);
}
string query = "ServerName='"+serverName+"'";
if (!ADP.IsEmpty(instanceName)) { // SQL BU DT 20006584: only append instanceName if present.
query += " AND InstanceName='"+instanceName+"'";
}
// SNI returns dupes - do not add them. SQL BU DT 290323
if (dataTable.Select(query).Length == 0) {
dataRow = dataTable.NewRow();
dataRow[0] = serverName;
dataRow[1] = instanceName;
dataRow[2] = isClustered;
dataRow[3] = version;
dataTable.Rows.Add(dataRow);
}
serverName = null;
instanceName = null;
isClustered = null;
version = null;
}
foreach(DataColumn column in dataTable.Columns) {
column.ReadOnly = true;
}
return dataTable;
}
}
}
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