Limpeza de Assembly não utilizado

O AssemblyCleanup exemplo contém um Procedimento Armazenado do .NET que limpa assemblies não utilizados no banco de dados atual consultando os catálogos de metadados. Seu único parâmetro é visible_assembliesusado para especificar se assemblies visíveis não utilizados devem ser descartados ou não. Um valor "false" significa que, por padrão, somente assemblies invisíveis não utilizados serão descartados, caso contrário, todos os assemblies não utilizados serão descartados. O conjunto de assemblies não utilizados são aqueles assemblies que não têm nenhum ponto de entrada definido (rotinas/tipos e agregações) e não há assemblies usados referenciando-os direta ou indiretamente.

Pré-requisitos

Para criar e executar este projeto, o seguinte software deve ser instalado:

• SQL Server ou SQL Server Express. Você pode obter o SQL Server Express gratuitamente no site de Documentação e Exemplos do SQL Server Express

• O banco de dados AdventureWorks que está disponível no site do Desenvolvedor do SQL Server

• SDK do .NET Framework 2.0 ou posterior ou Microsoft Visual Studio 2005 ou posterior. Você pode obter o SDK do .NET Framework gratuitamente.

• Além disso, as seguintes condições devem ser atendidas:

• A instância do SQL Server que você está usando deve ter a integração CLR habilitada.

• Para habilitar a integração do CLR, execute as seguintes etapas:

  Habilitando integração CLR

  • Execute os seguintes comandos de Transact-SQL:

  sp_configure 'clr enabled', 1

  GO

  RECONFIGURE

  GO

  Observação

  Para habilitar o CLR, você deve ter ALTER SETTINGS permissão de nível de servidor, que é mantida implicitamente por membros das funções de servidor fixas e serveradmin de sysadmin membros.

• O banco de dados AdventureWorks deve ser instalado na instância do SQL Server que você está usando.

• Se você não for um administrador da instância do SQL Server que está usando, deverá ter um administrador concedendo a você a permissão CreateAssembly para concluir a instalação.

Compilando o exemplo

Crie e execute o exemplo usando as seguintes instruções:

1. Abra um prompt de comando do Visual Studio ou do .NET Framework.

2. Se necessário, crie um diretório para o exemplo. Para este exemplo, usaremos C:\MySample.

3. Em c:\MySample, crie AssemblyCleanup.vb (para o exemplo do Visual Basic) ou AssemblyCleanup.cs (para o exemplo de C#) e copie o código de exemplo do Visual Basic ou C# apropriado (abaixo) no arquivo.

4. Compile o código de exemplo do prompt de linha de comando executando um dos seguintes, dependendo da sua escolha de idioma.

   • Vbc /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Data.dll,C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.dll,C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Transactions.dll,C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Xml.dll /target:library AssemblyCleanup.vb

   • Csc /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Data.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.XML.dll /target:library AssemblyCleanup.cs

5. Copie o código de instalação Transact-SQL em um arquivo e salve-o como Install.sql no diretório de exemplo.

6. Se o exemplo estiver instalado em outro diretório, edite C:\MySample\o arquivo Install.sql conforme indicado para apontar para esse local.

7. Implantar o assembly e o procedimento armazenado executando

   • sqlcmd -E -I -i install.sql

8. Copie Transact-SQL script de comando de teste em um arquivo e salve-o como test.sql no diretório de exemplo.

9. Executar o script de teste com o comando a seguir

   • sqlcmd -E -I -i test.sql

10. Copie o script de limpeza Transact-SQL em um arquivo e salve-o como cleanup.sql no diretório de exemplo.

11. Executar o script com o comando a seguir

    • sqlcmd -E -I -i cleanup.sql

Exemplo de código

Veja a seguir as listagens de código para este exemplo.

C#

using System;  
using System.Text;  
using System.Diagnostics;  
using System.Data.SqlClient;  
using System.Collections.Generic;  
using System.Globalization;  
using Microsoft.SqlServer.Server;  
  
    /// <summary>  
    /// Defines a CLR user defined function CleanupUnusedAssemblies that drops   
    /// all the invisible assemblies with no references.  
    /// </summary>  
    public sealed class AssemblyCleanup  
    {  
        private SqlTransaction transaction;  
  
        internal class AssemblySet  
        {  
            private Dictionary<int, object> m_dictionary;  
  
            /// <summary>  
            /// Initialize internal structures  
            /// </summary>  
            /// <returns></returns>  
            public AssemblySet()  
            {  
                m_dictionary = new Dictionary<int, object>();  
            }  
  
            /// <summary>  
            /// Adds an assembly id into the current AssemblySet if it is not   
            /// already part of it.  
            /// </summary>  
            /// <returns></returns>  
            public void Add(int assemblyId)  
            {  
                if (!m_dictionary.ContainsKey(assemblyId))  
                {  
                    m_dictionary.Add(assemblyId, null);  
                }  
            }  
  
            /// <summary>  
            /// Number of assembly ids stored in this instance  
            /// </summary>  
            /// <returns></returns>  
            public int Count  
            {  
                get  
                {  
                    return m_dictionary.Count;  
                }  
            }  
  
            /// <summary>  
            /// Returns the comma-separated list of assembly ids contained in this instance  
            /// </summary>  
            /// <returns>string value that represents a comma-separated list   
            /// of assembly ids</returns>  
            public string ToCommaSeparatedList()  
            {  
                StringBuilder sb = new StringBuilder();  
  
                if (m_dictionary.Count > 0)  
                {  
                    foreach (KeyValuePair<int, object> kv in m_dictionary)  
                    {  
                        sb.Append(kv.Key);  
                        sb.Append(",");  
                    }  
  
                    sb.Length--; // remove the trailing comma  
                }  
  
                return sb.ToString();  
            }  
        }  
  
        /// <summary>  
        /// Initializes an instance of AssemblyCleanup with a SqlTransaction  
        /// </summary>  
        /// <returns></returns>  
        private AssemblyCleanup(SqlTransaction transaction)  
        {  
            this.transaction = transaction;  
        }  
  
        /// <summary>  
        /// Helper function that creates a SqlCommand object as part of the current   
        /// transaction  
        /// </summary>  
        /// <returns></returns>  
        private SqlCommand CreateCommandInTransaction()  
        {  
            SqlCommand cmd = this.transaction.Connection.CreateCommand();  
  
            cmd.Transaction = this.transaction;  
  
            return cmd;  
        }  
  
        /// <summary>  
        /// Helper function that constructs an AssemblySet instance using the   
        /// first column of the resultset resulting from the query that was passed in.  
        /// </summary>  
        /// <param name="query"></param>  
        /// <returns></returns>  
        private AssemblySet GetAssemblySetFromQuery(string query)  
        {  
            SqlCommand cmd = CreateCommandInTransaction();  
  
            AssemblySet set = new AssemblySet();  
  
            cmd.CommandText = query;  
            using (SqlDataReader rd = cmd.ExecuteReader())  
            {  
                while (rd.Read())  
                {  
                    set.Add(rd.GetInt32(0));  
                }  
            }  
  
            return set;  
        }  
  
        /// <summary>  
        /// Constructs a DROP ASSEMBLY T-SQL statement using the AssemblySet   
        /// passed in as a parameter.  
        /// </summary>  
        /// <param name="set"></param>  
        /// <returns></returns>  
        private void DropAssemblies(AssemblySet unusedAssemblySet)  
        {  
            if (unusedAssemblySet.Count > 0)  
            {  
                StringBuilder assemblyNamesToDrop = new StringBuilder();  
  
                // Gather the list of assembly names we will drop later  
                SqlCommand cmd = CreateCommandInTransaction();  
  
                cmd.CommandText = String.Format(CultureInfo.InvariantCulture,  
                    "SELECT name FROM sys.assemblies WHERE assembly_id IN ({0});",  
                    unusedAssemblySet.ToCommaSeparatedList());  
                using (SqlDataReader rd = cmd.ExecuteReader())  
                {  
                    while (rd.Read())  
                    {  
                        assemblyNamesToDrop.Append("[");  
                        assemblyNamesToDrop.Append(rd.GetString(0));  
                        assemblyNamesToDrop.Append("],");  
                    }  
                }  
  
                // Remove trailing comma  
                assemblyNamesToDrop.Length--;  
  
                // Drop all assemblies at the same time  
                cmd.CommandText = String.Format(CultureInfo.InvariantCulture,  
                    "DROP ASSEMBLY {0}", assemblyNamesToDrop.ToString());  
                cmd.ExecuteNonQuery();  
            }  
        }  
  
        /// <summary>  
        /// Serves as the stored procedure entry point and drives the process   
        /// of expanding the "assemblies in use" set, negating it, and   
        /// dropping the results  
        /// </summary>  
        /// <param name="visibleAssemblies">If set to true, will also drop   
        /// unused visible assemblies. Otherwise, will only drop unused invisible   
        /// assemblies.</param>  
        /// <returns></returns>  
        [Microsoft.SqlServer.Server.SqlProcedure()]  
        public static void CleanupUnusedAssemblies(bool visibleAssemblies)  
        {  
            bool succeeded = false;  
            SqlConnection conn;  
            SqlTransaction transaction;  
            string sqlStatement;  
            AssemblySet assembliesToDrop;  
            AssemblyCleanup assemblyCleanup;  
  
            conn = new SqlConnection("context connection=true");  
            conn.Open();  
            transaction = conn.BeginTransaction();  
  
            try  
            {  
                // Create a set of assemblies in use by looking at   
                // the metadata of the current database  
                sqlStatement =  
                    "DECLARE @UsedAssembly TABLE (AssemblyID int NOT NULL); " +  
                    "DECLARE @RowCount int; " +  
                    "INSERT INTO @UsedAssembly " +  
                    "SELECT DISTINCT([assembly_id]) " +  
                    "FROM sys.assembly_modules " +  
                    "UNION " +  
                    "SELECT [assembly_id] " +  
                    "FROM sys.assembly_types; " +  
                    "SET @RowCount = @@ROWCOUNT; " +  
                    "WHILE @RowCount > 0 " +  
                    "BEGIN " +  
                    "INSERT INTO @UsedAssembly " +  
                    "SELECT [referenced_assembly_id] " +  
                    "FROM sys.assembly_references ar " +  
                    "INNER JOIN @UsedAssembly ua " +  
                    "ON ar.[assembly_id] = ua.AssemblyID " +  
                    "WHERE NOT EXISTS (SELECT * FROM @UsedAssembly WHERE AssemblyID = [referenced_assembly_id]) " +  
                    "SET @RowCount = @@ROWCOUNT; " +  
                    "END;";  
  
                if (visibleAssemblies)  
                {  
                    sqlStatement +=  
                        "SELECT assembly_id " +  
                        "FROM sys.assemblies " +  
                        "WHERE assembly_id NOT IN (SELECT AssemblyID FROM @UsedAssembly);";  
                }  
                else  
                {  
                    sqlStatement +=  
                        "SELECT assembly_id " +  
                        "FROM sys.assemblies " +  
                        "WHERE assembly_id NOT IN (SELECT AssemblyID FROM @UsedAssembly) " +  
                        "    AND is_visible = 0;";  
                }  
  
                // This marks the beginning of the transaction  
                assemblyCleanup = new AssemblyCleanup(transaction);  
  
                // Assemblies that are currently in use  
                assembliesToDrop  
                    = assemblyCleanup.GetAssemblySetFromQuery(sqlStatement);  
  
                assemblyCleanup.DropAssemblies(assembliesToDrop);  
  
                // Mark as succeeded  
                succeeded = true;  
            }  
            finally  
            {  
                // We must guarantee that we explicitly call either Commit()   
                // or Rollback() before we return.  
                if (succeeded)  
                {  
                    transaction.Commit();  
                }  
                else  
                {  
                    transaction.Rollback();  
                }  
                conn.Dispose();  
            }  
        }  
    }  
  

Visual Basic

Imports Microsoft.SqlServer.Server  
Imports Microsoft.VisualBasic  
Imports System  
Imports System.Collections  
Imports System.Collections.Generic  
Imports System.Data  
Imports System.Data.SqlClient  
Imports System.Diagnostics  
Imports System.Globalization  
Imports System.Text  
Imports System.Transactions  
Public NotInheritable Class AssemblyCleanup  
    Private transaction As SqlTransaction  
  
    Friend Class AssemblySet  
        Private m_dictionary As Dictionary(Of Integer, Object)  
  
        ''' <summary>  
        ''' Initialize internal structures  
        ''' </summary>  
        ''' <returns></returns>  
        Public Sub New()  
            m_dictionary = New Dictionary(Of Integer, Object)  
        End Sub  
  
        ''' <summary>  
        ''' Adds an assembly id into the current AssemblySet if it is not already part of it.  
        ''' </summary>  
        ''' <returns></returns>  
        Public Sub Add(ByVal assemblyId As Integer)  
            If Not m_dictionary.ContainsKey(assemblyId) Then  
                m_dictionary.Add(assemblyId, Nothing)  
            End If  
        End Sub  
  
        ''' <summary>  
        ''' Number of assembly ids stored in this instance  
        ''' </summary>  
        ''' <returns></returns>  
        Public ReadOnly Property Count() As Integer  
            Get  
                Return m_dictionary.Count  
            End Get  
        End Property  
  
        ''' <summary>  
        ''' Returns the comma-separated list of assembly ids contained in this instance  
        ''' </summary>  
        ''' <returns>string value that represents a comma-separated list of assembly ids</returns>  
        Public Function ToCommaSeparatedList() As String  
            Dim sb As New StringBuilder()  
  
            If m_dictionary.Count > 0 Then  
                For Each kv As KeyValuePair(Of Integer, Object) In m_dictionary  
                    If (True) Then  
                        sb.Append(kv.Key)  
                        sb.Append(",")  
                    End If  
                Next  
  
                sb.Length -= 1 ' remove the trailing comma  
            End If  
  
            Return sb.ToString()  
  
        End Function  
    End Class  
  
    ''' <summary>  
    ''' Initializes an instance of AssemblyCleanup with a SqlTransaction  
    ''' </summary>  
    ''' <returns></returns>  
    Private Sub New(ByVal trans As SqlTransaction)  
        Me.transaction = trans  
    End Sub  
  
    ''' <summary>  
    ''' Helper function that creates a SqlCommand object as part of the   
    ''' current transaction  
    ''' </summary>  
    ''' <returns></returns>  
    Private Function CreateCommandInTransaction() As SqlCommand  
        Dim cmd As SqlCommand = transaction.Connection.CreateCommand()  
  
        cmd.Transaction = Me.transaction  
  
        Return cmd  
    End Function  
  
    ''' <summary>  
    ''' Helper function that constructs an AssemblySet instance using the   
    ''' first column of the resultset resulting from the query that was passed in.  
    ''' </summary>  
    ''' <param name="query"></param>  
    ''' <returns></returns>  
    Private Function GetAssemblySetFromQuery(ByVal query As String) As AssemblySet  
        Dim cmd As SqlCommand = CreateCommandInTransaction()  
        Dim [set] As New AssemblySet()  
  
        cmd.CommandText = query  
        Dim rd As SqlDataReader = cmd.ExecuteReader()  
        Try  
            While rd.Read()  
                [set].Add(rd.GetInt32(0))  
            End While  
        Finally  
            rd.Dispose()  
        End Try  
  
        Return [set]  
    End Function  
  
    ''' <summary>  
    ''' Constructs a DROP ASSEMBLY T-SQL statement using the AssemblySet   
    ''' passed in as a parameter.  
    ''' </summary>  
    ''' <param name="set"></param>  
    ''' <returns></returns>  
    Private Sub DropAssemblies(ByVal unusedAssemblySet As AssemblySet)  
        If unusedAssemblySet.Count > 0 Then  
            Dim assemblyNamesToDrop As New StringBuilder()  
  
            ' Gather the list of assembly names we will drop later  
            Dim cmd As SqlCommand = CreateCommandInTransaction()  
  
            cmd.CommandText = String.Format(CultureInfo.InvariantCulture, _  
                "SELECT name FROM sys.assemblies WHERE assembly_id IN ({0});", _  
                unusedAssemblySet.ToCommaSeparatedList())  
            Dim rd As SqlDataReader = cmd.ExecuteReader()  
            Try  
                While rd.Read()  
                    assemblyNamesToDrop.Append("[")  
                    assemblyNamesToDrop.Append(rd.GetString(0))  
                    assemblyNamesToDrop.Append("],")  
                End While  
            Finally  
                rd.Dispose()  
            End Try  
  
            ' Remove trailing comma  
            assemblyNamesToDrop.Length -= 1  
  
            ' Drop all assemblies at the same time  
            cmd.CommandText = String.Format(CultureInfo.InvariantCulture, _  
                "DROP ASSEMBLY {0}", assemblyNamesToDrop.ToString())  
            cmd.ExecuteNonQuery()  
        End If  
    End Sub  
  
    ''' <summary>  
    ''' Serves as the stored procedure entry point and drives the process of   
    ''' expanding the "assemblies in use" set, negating it, and dropping   
    ''' the results.  
    ''' </summary>  
    ''' <param name="visibleAssemblies">If set to true, will also drop unused   
    ''' visible assemblies. Otherwise, will only drop unused invisible assemblies.</param>  
    ''' <returns></returns>  
    <Microsoft.SqlServer.Server.SqlProcedure()> _  
    Public Shared Sub CleanupUnusedAssemblies(ByVal visibleAssemblies As Boolean)  
  
        Dim succeeded As Boolean = False  
        Dim conn As SqlConnection  
        Dim transaction As SqlTransaction  
        Dim sqlStatement As String  
        Dim assembliesToDrop As AssemblySet  
        Dim assemblyCleanup As AssemblyCleanup  
  
        conn = New SqlConnection("context connection=true")  
        conn.Open()  
        transaction = conn.BeginTransaction()  
  
        Try  
            ' Create a set of assemblies in use by looking at   
            ' the metadata of the current database  
            sqlStatement = "DECLARE @UsedAssembly TABLE (AssemblyID int NOT NULL); " & _  
                "DECLARE @RowCount int; " & _  
                "INSERT INTO @UsedAssembly " & _  
                "SELECT DISTINCT([assembly_id]) " & _  
                "FROM sys.assembly_modules " & _  
                "UNION " & _  
                "SELECT [assembly_id] " & _  
                "FROM sys.assembly_types; " & _  
                "SET @RowCount = @@ROWCOUNT; " & _  
                "WHILE @RowCount > 0 " & _  
                "BEGIN " & _  
                "INSERT INTO @UsedAssembly " & _  
                "SELECT [referenced_assembly_id] " & _  
                "FROM sys.assembly_references ar " & _  
                "INNER JOIN @UsedAssembly ua " & _  
                "ON ar.[assembly_id] = ua.AssemblyID " & _  
                "WHERE NOT EXISTS (SELECT * FROM @UsedAssembly WHERE AssemblyID = [referenced_assembly_id]) " & _  
                "SET @RowCount = @@ROWCOUNT; " & _  
                "END;"  
  
            If visibleAssemblies Then  
                sqlStatement += "SELECT assembly_id " & _  
                    "FROM sys.assemblies " & _  
                    "WHERE assembly_id NOT IN (SELECT AssemblyID FROM @UsedAssembly);"  
            Else  
                sqlStatement += "SELECT assembly_id " & _  
                    "FROM sys.assemblies " & _  
                    "WHERE assembly_id NOT IN (SELECT AssemblyID FROM @UsedAssembly) " & _  
                    "    AND is_visible = 0;"  
            End If  
  
            ' This marks the beginning of the transaction  
            assemblyCleanup = New AssemblyCleanup(transaction)  
  
            ' Assemblies that are currently in use  
            assembliesToDrop _  
                = assemblyCleanup.GetAssemblySetFromQuery(sqlStatement)  
  
            assemblyCleanup.DropAssemblies(assembliesToDrop)  
  
            ' Mark as succeeded  
            succeeded = True  
        Finally  
            ' We must guarantee that we explicitly call either Commit()   
            ' or Rollback() before we return.  
            If succeeded Then  
                transaction.Commit()  
            Else  
                transaction.Rollback()  
            End If  
            conn.Dispose()  
        End Try  
    End Sub  
End Class  

Esse é o script de instalação Transact-SQL (Install.sql), que implanta o assembly e cria o procedimento armazenado no banco de dados.

USE AdventureWorks;  
GO  
IF EXISTS (SELECT * FROM sys.objects WHERE name = N'CleanupUnusedAssemblies')  
DROP PROCEDURE CleanupUnusedAssemblies;  
GO  
  
IF EXISTS (SELECT * FROM sys.assemblies WHERE name = N'AssemblyCleanupUtils')   
DROP ASSEMBLY AssemblyCleanupUtils;  
GO  
DECLARE @SamplesPath nvarchar(1024)  
  
-- You may need to modify the value of the this variable if you have installed the sample someplace other than the default location.  
Set @SamplesPath = 'C:\MySample\'  
  
CREATE ASSEMBLY AssemblyCleanupUtils   
FROM @SamplesPath + 'AssemblyCleanup.dll'   
WITH permission_set = Safe;  
GO  
  
CREATE PROCEDURE CleanupUnusedAssemblies (  
@visible_assemblies bit  
) AS  
EXTERNAL NAME [AssemblyCleanupUtils].[AssemblyCleanup].CleanupUnusedAssemblies;  
GO  

Isto é test.sql, que testa o exemplo executando o procedimento armazenado.

USE AdventureWorks;  
GO  
  
PRINT 'Before cleanup...'  
SELECT [name] FROM sys.assemblies;  
GO  
  
-- pass in false, which means the cleanup will only include invisible assemblies  
EXEC dbo.CleanupUnusedAssemblies false;  
GO  
  
PRINT 'After cleanup'  
SELECT [name] FROM sys.assemblies;  

O Transact-SQL a seguir remove o assembly e o procedimento armazenado do banco de dados.

USE AdventureWorks;  
GO  
  
IF EXISTS (SELECT * FROM sys.objects WHERE name = N'CleanupUnusedAssemblies')  
DROP PROCEDURE CleanupUnusedAssemblies;  
GO  
  
IF EXISTS (SELECT * FROM sys.assemblies WHERE name = N'AssemblyCleanupUtils')   
DROP ASSEMBLY AssemblyCleanupUtils;  
GO  

Consulte Também

Cenários de uso e exemplos para a integração de CLR (Common Language Runtime)