Pulizia di assembly inutilizzati

L'esempio AssemblyCleanup contiene una stored procedure .NET che pulisce gli assembly inutilizzati nel database corrente eseguendo query sui cataloghi di metadati. L'unico parametro, visible_assemblies, viene usato per specificare se gli assembly visibili inutilizzati devono essere eliminati o meno. Il valore "false" indica che per impostazione predefinita verranno eliminati solo gli assembly invisibili inutilizzati. In caso contrario, tutti gli assembly inutilizzati verranno eliminati. Il set di assembly inutilizzati sono gli assembly che non dispongono di punti di ingresso definiti (routine/tipi e aggregazioni) e che non vi sono assembly usati che fanno riferimento direttamente o indirettamente.

Prerequisiti

Per creare ed eseguire questo progetto, è necessario installare il software seguente:

SQL Server o SQL Server Express. È possibile ottenere gratuitamente SQL Server Express dalla documentazione di SQL Server Express e dal sito Web degli esempi
Database AdventureWorks disponibile nel sito Web per sviluppatori di SQL Server
.NET Framework SDK 2.0 o versione successiva o Microsoft Visual Studio 2005 o versione successiva. È possibile ottenere gratuitamente .NET Framework SDK.
Inoltre, devono essere soddisfatte le condizioni seguenti:
L'istanza di SQL Server in uso deve avere l'integrazione CLR abilitata.
Per abilitare l'integrazione con CLR, seguire questa procedura:

Abilitazione dell'integrazione con CLR
- Eseguire i comandi di Transact-SQL seguenti:
sp_configure 'clr enabled', 1

GO

RECONFIGURE

GO

Annotazioni

Per abilitare CLR, è necessario disporre ALTER SETTINGS dell'autorizzazione a livello di server, che viene mantenuta in modo implicito dai membri dei ruoli predefiniti del sysadmin server e serveradmin .
Il database AdventureWorks deve essere installato nell'istanza di SQL Server in uso.
Se non si è un amministratore per l'istanza di SQL Server in uso, è necessario disporre di un amministratore che conceda l'autorizzazione CreateAssembly per completare l'installazione.

Compilazione dell'esempio

Creare ed eseguire l'esempio usando le istruzioni seguenti:

Aprire un prompt dei comandi di Visual Studio o .NET Framework.
Se necessario, creare una directory per l'esempio. Per questo esempio si userà C:\MySample.
In c:\MySample creare AssemblyCleanup.vb (per l'esempio di Visual Basic) o AssemblyCleanup.cs (per l'esempio C#) e copiare il codice di esempio di Visual Basic o C# appropriato (di seguito) nel file.
Compilare il codice di esempio dal prompt della riga di comando eseguendo una delle opzioni seguenti, a seconda del linguaggio scelto.
- 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
Copiare il codice di installazione Transact-SQL in un file e salvarlo come Install.sql nella directory di esempio.
Se l'esempio viene installato in una directory diversa, C:\MySample\modificare il file Install.sql come indicato in modo che punti a tale percorso.
Distribuire l'assembly e la stored procedure eseguendo
- sqlcmd -E -I -i install.sql
Copiare Transact-SQL script del comando di test in un file e salvarlo come test.sql nella directory di esempio.
Eseguire lo script di test con il comando seguente
- sqlcmd -E -I -i test.sql
Copiare lo script di pulizia Transact-SQL in un file e salvarlo come cleanup.sql nella directory di esempio.
Eseguire lo script con il comando seguente
- sqlcmd -E -I -i cleanup.sql

Codice di esempio

Di seguito sono riportati gli elenchi di codice per questo esempio.

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

Si tratta dello script di installazione Transact-SQL (Install.sql), che distribuisce l'assembly e crea la stored procedure nel database.

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

Si tratta di test.sql, che verifica l'esempio eseguendo la stored procedure.

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;

Nell'Transact-SQL seguente l'assembly e la stored procedure vengono rimossi dal database.

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

Vedere anche

Scenari di utilizzo ed esempi per l'integrazione con CLR (Common Language Runtime)

Last updated on 2017-06-13

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