Limpieza del ensamblado sin usar
El ejemplo AssemblyCleanup contiene un procedimiento almacenado de .NET que limpia los ensamblados no usados en la base de datos actual mediante consultas en los catálogos de metadatos. Su único parámetro, visible_assemblies, se utiliza para especificar si se deben quitar los ensamblados visibles no usados o no. Un valor de 'false' significa de forma predeterminada que solo se quitarán los ensamblados no visibles no usados; en los demás casos se quitarán todos los ensamblados no usados. El conjunto de ensamblados no usados está formado por aquellos que no tienen ningún punto de entrada definido (rutinas, tipos y agregados) y que no tienen ningún ensamblado utilizado que haga referencia a ellos directa o indirectamente.
Requisitos previos
Para crear y ejecutar este proyecto se debe instalar el siguiente software:
SQL Server o SQL Server Express. Puede obtener SQL Server Express de forma gratuita desde el sitio web de documentación y ejemplos de SQL Server Express.
La base de datos AdventureWorks que está disponible en el sitio web para desarrolladores de SQL Server.
.NET Framework SDK 2.0 o posterior, o Microsoft Visual Studio 2005 o posterior. Puede obtener .NET Framework SDK de forma gratuita.
Además, se deben cumplir las siguientes condiciones:
La instancia de SQL Server que está utilizando debe tener habilitada la integración con CLR.
Para habilitar la integración con CLR, siga estos pasos:
Habilitar la integración con CLR
- Ejecute los siguientes comandos Transact-SQL:
sp_configure 'clr enabled', 1
GO
RECONFIGURE
GO
[!NOTA]
Para habilitar CLR, debe tener el permiso de nivel de servidor ALTER SETTINGS, que se concede implícitamente a los miembros de los roles fijos de servidor sysadmin y serveradmin.
La base de datos AdventureWorks debe estar instalada en la instancia de SQL Server que está utilizando.
Si no es administrador de la instancia de SQL Server que utiliza, debe hacer que un administrador le conceda el permiso CreateAssembly para completar la instalación.
Generar el ejemplo
Cree y ejecute el ejemplo utilizando las siguientes instrucciones:
Abra un símbolo del sistema de Visual Studio o de .NET Framework.
Si es necesario, cree un directorio para el ejemplo. Para este ejemplo, utilizaremos C:\MySample.
En c:\MySample, cree AssemblyCleanup.vb (para el ejemplo de Visual Basic) o AssemblyCleanup.cs (para el ejemplo de C#) y copie el código de ejemplo de Visual Basic o de C# que corresponda (más abajo) en el archivo.
Compile el código muestra desde el símbolo del sistema ejecutando uno de los comandos siguientes, dependiendo de su opción de lenguaje.
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
Copie el código de instalación de Transact-SQL en un archivo y guárdelo como Install.sql en el directorio de ejemplo.
Si el ejemplo está instalado en un directorio distinto de C:\MySample\, modifique el script Install.sql del archivo como se indica para señalar a esa ubicación.
Implemente el ensamblado y el procedimiento almacenado ejecutando
- sqlcmd -E -I -i install.sql
Copie el script de comando de prueba de Transact-SQL en un archivo y guárdelo como test.sql en el directorio de ejemplo.
Ejecute el script de prueba con el siguiente comando
- sqlcmd -E -I -i test.sql
Copie el script de limpieza de Transact-SQL en un archivo y guárdelo como cleanup.sql en el directorio de ejemplo.
Ejecute el script con el siguiente comando
- sqlcmd -E -I -i cleanup.sql
Código muestra
A continuación se muestran las listas de código para este ejemplo.
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-seperated list
/// of assembly ids</returns>
public string ToCommaSeperatedList()
{
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.ToCommaSeperatedList());
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-seperated list of assembly ids</returns>
Public Function ToCommaSeperatedList() 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.ToCommaSeperatedList())
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
Este es el script de instalación de Transact-SQL (Install.sql), que implementa el ensamblado y crea el procedimiento almacenado en la base de datos.
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
Este es el script test.sql, que prueba el ejemplo ejecutando el procedimiento almacenado.
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;
El script Transact-SQL siguiente quita el ensamblado y el procedimiento almacenado de la base de datos.
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
Vea también
Conceptos
Escenarios de uso y ejemplos para la integración de Common Language Runtime (CLR)