Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Data/System/Data/Sql/SqlDataSourceEnumerator.cs

@@ -0,0 +1,167 @@
+//------------------------------------------------------------------------------
+// <copyright file="SqlDataSourceEnumerator.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.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() {
+#if MONO
+            throw new NotImplementedException ();
+#else
+            (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());
+#endif
+        }
+        
+        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;
+        }
+    }
+}