From 233c03093470b7978e064cab900976353ed6ddce Mon Sep 17 00:00:00 2001
From: Lombiq <registrator@lombiq.com>
Date: Wed, 29 Jan 2014 18:04:02 +0100
Subject: [PATCH] UpgradeService now disposes NHibernate sessions, preventing
 possible SQL server connection pool saturation

---
 .../Upgrade/Services/UpgradeService.cs        | 110 +++++++++---------
 1 file changed, 54 insertions(+), 56 deletions(-)

diff --git a/src/Orchard.Web/Modules/Upgrade/Services/UpgradeService.cs b/src/Orchard.Web/Modules/Upgrade/Services/UpgradeService.cs
index 4416b1d56..6446fe5aa 100644
--- a/src/Orchard.Web/Modules/Upgrade/Services/UpgradeService.cs
+++ b/src/Orchard.Web/Modules/Upgrade/Services/UpgradeService.cs
@@ -39,75 +39,74 @@ namespace Upgrade.Services {
                 values.Add(parameters);
             });
 
-            var sessionFactory = _sessionFactoryHolder.GetSessionFactory();
-            var session = sessionFactory.OpenSession();
 
-            var connection = session.Connection;
+            using (var session = _sessionFactoryHolder.GetSessionFactory().OpenSession()) {
+                var connection = session.Connection;
 
-            foreach (var record in values) {
-                var command = connection.CreateCommand();
-                var statement = String.Format("INSERT INTO {0} (", toPrefixedTableName);
+                foreach (var record in values) {
+                    var command = connection.CreateCommand();
+                    var statement = String.Format("INSERT INTO {0} (", toPrefixedTableName);
 
-                foreach (var keyValuePair in record) {
-                    if (ignoreColumns.Contains(keyValuePair.Key)) {
-                        continue;
+                    foreach (var keyValuePair in record) {
+                        if (ignoreColumns.Contains(keyValuePair.Key)) {
+                            continue;
+                        }
+
+                        statement += keyValuePair.Key;
+                        if (keyValuePair.Key != record.Last().Key) {
+                            statement += ", ";
+                        }
                     }
 
-                    statement += keyValuePair.Key;
-                    if (keyValuePair.Key != record.Last().Key) {
-                        statement += ", ";
-                    }
-                }
+                    statement += ") VALUES ( ";
 
-                statement += ") VALUES ( ";
+                    foreach (var keyValuePair in record) {
+                        if (ignoreColumns.Contains(keyValuePair.Key)) {
+                            continue;
+                        }
 
-                foreach (var keyValuePair in record) {
-                    if (ignoreColumns.Contains(keyValuePair.Key)) {
-                        continue;
+                        var parameter = command.CreateParameter();
+                        parameter.ParameterName = "@" + keyValuePair.Key;
+                        parameter.Value = keyValuePair.Value;
+
+                        statement += parameter.ParameterName;
+                        if (keyValuePair.Key != record.Last().Key) {
+                            statement += ", ";
+                        }
+
+                        command.Parameters.Add(parameter);
                     }
 
-                    var parameter = command.CreateParameter();
-                    parameter.ParameterName = "@" + keyValuePair.Key;
-                    parameter.Value = keyValuePair.Value;
+                    statement += ")";
 
-                    statement += parameter.ParameterName;
-                    if (keyValuePair.Key != record.Last().Key) {
-                        statement += ", ";
-                    }
+                    command.CommandText = statement;
 
-                    command.Parameters.Add(parameter);
-                }
-
-                statement += ")";
-
-                command.CommandText = statement;
-
-                command.ExecuteNonQuery();
+                    command.ExecuteNonQuery();
+                } 
             }
         }
 
         public void ExecuteReader(string sqlStatement, Action<IDataReader, IDbConnection> action) {
-            var sessionFactory = _sessionFactoryHolder.GetSessionFactory();
-            var session = sessionFactory.OpenSession();
+            using (var session = _sessionFactoryHolder.GetSessionFactory().OpenSession()) {
+                var command = session.Connection.CreateCommand();
+                command.CommandText = string.Format(sqlStatement);
 
-            var command = session.Connection.CreateCommand();
-            command.CommandText = string.Format(sqlStatement);
+                var reader = command.ExecuteReader();
 
-            var reader = command.ExecuteReader();
-
-            while (reader != null && reader.Read()) {
-                try {
-                    if (action != null) {
-                        action(reader, session.Connection);
+                while (reader != null && reader.Read()) {
+                    try {
+                        if (action != null) {
+                            action(reader, session.Connection);
+                        }
+                    }
+                    catch (Exception e) {
+                        Logger.Error(e, "Error while executing custom SQL Statement in Upgrade.");
                     }
                 }
-                catch (Exception e) {
-                    Logger.Error(e, "Error while executing custom SQL Statement in Upgrade.");
-                }
-            }
 
-            if (reader != null && !reader.IsClosed) {
-                reader.Close();
+                if (reader != null && !reader.IsClosed) {
+                    reader.Close();
+                } 
             }
         }
 
@@ -122,16 +121,15 @@ namespace Upgrade.Services {
         public bool TableExists(string tableName) {
             // While not particularly nice (or fast with many tables) this seems to be a database-agnostic way of checking the existence
             // of a table.
-            var sessionFactory = _sessionFactoryHolder.GetSessionFactory();
-            var session = sessionFactory.OpenSession();
+            using (var session = _sessionFactoryHolder.GetSessionFactory().OpenSession()) {
+                var connection = session.Connection as DbConnection;
 
-            var connection = session.Connection as DbConnection;
+                if (connection == null) {
+                    throw new InvalidOperationException("The database connection object should derive from DbConnection to check if a table exists.");
+                }
 
-            if (connection == null) {
-                throw new InvalidOperationException("The database connection object should derive from DbConnection to check if a table exists.");
+                return connection.GetSchema("Tables").Rows.Cast<DataRow>().Any(row => row["TABLE_NAME"].ToString() == tableName); 
             }
-
-            return connection.GetSchema("Tables").Rows.Cast<DataRow>().Any(row => row["TABLE_NAME"].ToString() == tableName);
         }
     }
 }