LogRecordSequence Classe

Definizione

Rappresenta una sequenza di record in un oggetto LogStore.Represents a record sequence stored in a LogStore.

public ref class LogRecordSequence sealed : IDisposable, System::IO::Log::IRecordSequence
public sealed class LogRecordSequence : IDisposable, System.IO.Log.IRecordSequence
type LogRecordSequence = class
    interface IRecordSequence
    interface IDisposable
Public NotInheritable Class LogRecordSequence
Implements IDisposable, IRecordSequence
Ereditarietà
LogRecordSequence
Implementazioni

Esempi

In questo esempio viene illustrato come utilizzare la classe LogRecordSequence:This example shows how to use the LogRecordSequence class:

using System;
using System.IO;
using System.Collections.Generic;
using System.Text;
using System.IO.Log;

namespace MyLogRecordSequence
{
    public class MyLog
    {
        string logName = "test.log";
        string logContainer = "MyExtent0";
        int containerSize = 32 * 1024;
        LogRecordSequence sequence = null;
        bool delete = true;

        // These are used in the TailPinned event handler.
        public static LogRecordSequence MySequence = null;
        public static bool AdvanceBase = true;

        public MyLog()
        {
            // Create a LogRecordSequence.
            sequence = new LogRecordSequence(this.logName,
                                              FileMode.CreateNew,
                                              FileAccess.ReadWrite,
                                              FileShare.None);

            // At least one container/extent must be added for Log Record Sequence.
            sequence.LogStore.Extents.Add(this.logContainer, this.containerSize);
     
            MySequence = sequence;

        }

        public void AddExtents()
        {
            // Add two additional extents. The extents are 
            // of the same size as the first extent.
            sequence.LogStore.Extents.Add("MyExtent1");
            sequence.LogStore.Extents.Add("MyExtent2");
        }

        public void EnumerateExtents()
        {
            LogStore store = sequence.LogStore;

            Console.WriteLine("Enumerating Log Extents...");
            Console.WriteLine("    Extent Count: {0} extents", store.Extents.Count);
            Console.WriteLine("    Extents Are...");
            foreach (LogExtent extent in store.Extents)
            {
                Console.WriteLine("      {0} ({1}, {2})",
                                  Path.GetFileName(extent.Path),
                                  extent.Size,
                                  extent.State);
            }
            Console.WriteLine("    Free Extents: {0} Free", store.Extents.FreeCount);   
        }

        public void SetLogPolicy()
        {
            Console.WriteLine();
            Console.WriteLine("Setting current log policy...");

            // SET LOG POLICY

            LogPolicy policy = sequence.LogStore.Policy;

            // Set AutoGrow policy. This enables the log to automatically grow
            // when the existing extents are full. New extents are added until
            // we reach the MaximumExtentCount extents.
            // AutoGrow policy is supported only in Windows Vista and not available in R2.
            
            //policy.AutoGrow = true;

            // Set the Growth Rate in terms of extents. This policy specifies
            // "how much" the log should grow. 
            policy.GrowthRate = new PolicyUnit(2, PolicyUnitType.Extents);

            // Set the AutoShrink policy. This enables the log to automatically
            // shrink if the available free space exceeds the shrink percentage. 
            // AutoGrow/shrink policy is supported only in Windows Vista and not available in R2.
            
            //policy.AutoShrinkPercentage = new PolicyUnit(30, PolicyUnitType.Percentage);

            // Set the PinnedTailThreshold policy.
            // A tail pinned event is triggered when there is no
            // log space available and log space may be freed by advancing the base.
            // The user must handle the tail pinned event by advancing the base of the log. 
            // If the user is not able to move the base of the log, the user should report with exception in
            // the tail pinned handler.
            // PinnedTailThreashold policy dictates the amount of space that the TailPinned event requests 
            // for advancing the base of the log. The amount of space can be in percentage or in terms of bytes 
            // which is rounded off to the nearest containers in CLFS. The default is 35 percent.

            
            policy.PinnedTailThreshold = new PolicyUnit(10, PolicyUnitType.Percentage);

            // Set the maximum extents the log can have.
            policy.MaximumExtentCount = 6;
            
            // Set the minimum extents the log can have.
            policy.MinimumExtentCount = 2;
            
            // Set the prefix for new containers that are added. 
            // when AutoGrow is enabled.
            //policy.NewExtentPrefix = "MyLogPrefix";
            
            // Set the suffix number for new containers that are added.
            // when AutoGrow is enabled. 
            policy.NextExtentSuffix = 3;

            // Commit the log policy.
            policy.Commit();

            // Refresh updates the IO.Log policy properties with current log policy 
            // set in the log. 
            policy.Refresh();

            // LOG POLICY END
            // 

            //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
            // Setting up IO.Log provided capabilities...
            // 

            // SET RETRY APPEND

            // IO.Log provides a mechanism similar to AutoGrow.
            // If the existing log is full and an append fails, setting RetryAppend
            // invokes the CLFS policy engine to add new extents and re-tries
            // record appends. If MaximumExtent count has been reached, 
            // a SequenceFullException is thrown. 
            // 

            sequence.RetryAppend = true;

            // RETRY APPEND END

            // REGISTER FOR TAILPINNED EVENT NOTIFICATIONS

            // Register for TailPinned Event by passing in an event handler.
            // An event is raised when the log full condition is reached.
            // The user should either advance the base sequence number to the 
            // nearest valid sequence number recommended in the tail pinned event or
            // report a failure that it is not able to advance the base sequence 
            // number. 
            //

            sequence.TailPinned += new EventHandler<TailPinnedEventArgs>(HandleTailPinned);  

            Console.WriteLine("Done...");
        }

        public void ShowLogPolicy()
        {
            Console.WriteLine();
            Console.WriteLine("Showing current log policy...");

            LogPolicy policy = sequence.LogStore.Policy;

            Console.WriteLine("    Minimum extent count:  {0}", policy.MinimumExtentCount);
            Console.WriteLine("    Maximum extent count:  {0}", policy.MaximumExtentCount);
            Console.WriteLine("    Growth rate:           {0}", policy.GrowthRate);
            Console.WriteLine("    Pinned tail threshold: {0}", policy.PinnedTailThreshold);
            Console.WriteLine("    Auto shrink percent:   {0}", policy.AutoShrinkPercentage);
            Console.WriteLine("    Auto grow enabled:     {0}", policy.AutoGrow);
            Console.WriteLine("    New extent prefix:     {0}", policy.NewExtentPrefix);
            Console.WriteLine("    Next extent suffix:    {0}", policy.NextExtentSuffix);

    }

        // Append records. Appending three records.  
        public void AppendRecords()
        {
            Console.WriteLine("Appending Log Records...");
            SequenceNumber previous = SequenceNumber.Invalid;

            previous = sequence.Append(CreateData("Hello World!"), SequenceNumber.Invalid, SequenceNumber.Invalid, RecordAppendOptions.ForceFlush);
            previous = sequence.Append(CreateData("This is my first Logging App"), SequenceNumber.Invalid, SequenceNumber.Invalid, RecordAppendOptions.ForceFlush);
            previous = sequence.Append(CreateData("Using LogRecordSequence..."), SequenceNumber.Invalid, SequenceNumber.Invalid, RecordAppendOptions.ForceFlush);
        
            Console.WriteLine("Done...");
        }


        // Read the records added to the log. 
        public void ReadRecords()
        {
            Encoding enc = Encoding.Unicode;

            Console.WriteLine();

            Console.WriteLine("Reading Log Records...");
            try
            {
                foreach (LogRecord record in this.sequence.ReadLogRecords(this.sequence.BaseSequenceNumber, LogRecordEnumeratorType.Next))
                {
                    byte[] data = new byte[record.Data.Length];
                    record.Data.Read(data, 0, (int)record.Data.Length);
                    string mystr = enc.GetString(data);
                    Console.WriteLine("    {0}", mystr);
                }
            }
            catch (Exception e)
            {
                Console.WriteLine("Exception {0} {1}", e.GetType(), e.Message);
            }

            Console.WriteLine();
        }

        public void FillLog()
        {
            bool append = true;

            while (append)
            {
                try
                {
                    sequence.Append(CreateData(16 * 1024), SequenceNumber.Invalid, SequenceNumber.Invalid, RecordAppendOptions.ForceFlush);
                }

                catch (SequenceFullException)
                {
                    Console.WriteLine("Log is Full...");
                    append = false;
                }
            }
        }

        // Dispose the record sequence and delete the log file. 
        public void Cleanup()
        {
            // Dispose the sequence
            sequence.Dispose();

            // Delete the log file.
            if (delete)
            {
                try
                {
                    // This deletes the base log file and all the extents associated with the log.
                    LogStore.Delete(this.logName);
                }
                catch (Exception e)
                {
                    Console.WriteLine("Exception {0} {1}", e.GetType(), e.Message);
                }
            }
        }

        // Converts the given data to an Array of ArraySegment<byte> 
        public static IList<ArraySegment<byte>> CreateData(string str)
        {
            Encoding enc = Encoding.Unicode;

            byte[] array = enc.GetBytes(str);

            ArraySegment<byte>[] segments = new ArraySegment<byte>[1];
            segments[0] = new ArraySegment<byte>(array);

            return Array.AsReadOnly<ArraySegment<byte>>(segments);
        }

        public static IList<ArraySegment<byte>> CreateData(int size)
        {
            byte[] array = new byte[size];

            Random rnd = new Random();
            rnd.NextBytes(array);

            ArraySegment<byte>[] segments = new ArraySegment<byte>[1];
            segments[0] = new ArraySegment<byte>(array);

            return Array.AsReadOnly<ArraySegment<byte>>(segments);
        }

        public static SequenceNumber GetAdvanceBaseSeqNumber(SequenceNumber recTargetSeqNum)
        {
            SequenceNumber targetSequenceNumber = SequenceNumber.Invalid;

            Console.WriteLine("Getting actual target sequence number...");
            
            // 
            // Implement the logic for returning a valid sequence number closer to
            // recommended target sequence number. 
            //

            return targetSequenceNumber;
        }

        public static void HandleTailPinned(object arg, TailPinnedEventArgs tailPinnedEventArgs)
        {
            Console.WriteLine("TailPinned has fired");

            // Based on the implementation of a logging application, the log base can be moved
            // to free up more log space and if it is not possible to move the 
            // base, the application should report by throwing an exception.

            if(MyLog.AdvanceBase)
            {
                try
                {
                    // TailPnnedEventArgs has the recommended sequence number and its generated 
                    // based on PinnedTailThreshold policy. 
                    // This does not map to an actual sequence number in the record sequence
                    // but an approximation and potentially frees up the threshold % log space
                    // when the log base is advanced to a valid sequence number closer to the 
                    // recommended sequence number. 
                    // The user should use this sequence number to locate a closest valid sequence
                    // number to advance the base of the log.

                    SequenceNumber recommendedTargetSeqNum = tailPinnedEventArgs.TargetSequenceNumber; 
                    
                    // Get the actual Target sequence number.
                    SequenceNumber actualTargetSeqNum = MyLog.GetAdvanceBaseSeqNumber(recommendedTargetSeqNum);

                    MySequence.AdvanceBaseSequenceNumber(actualTargetSeqNum);
                }
                catch (Exception e)
                {
                    Console.WriteLine("Exception thrown {0} {1}", e.GetType(), e.Message);
                }
            }
            else
            {
                // Report back Error if under some conditions the log cannot
                // advance the base sequence number.

                Console.WriteLine("Reporting Error! Unable to move the base sequence number!");
                throw new IOException();
            }
        }
    }

    class LogSample
    {
        static void Main(string[] args)
        {
            // Create log record sequence.
            MyLog log = new MyLog();

            // Add additional extents.
            log.AddExtents();

            // Enumerate the current log extents.
            log.EnumerateExtents();

            // Set log policies and register for TailPinned event notifications. 
            log.SetLogPolicy();

            log.ShowLogPolicy();
            
            // Append a few records and read the appended records. 
            log.AppendRecords();
            log.ReadRecords();

            // Fill the Log to trigger log growth...and subsequent TailPinned notifications.
            log.FillLog();

            log.EnumerateExtents();

            log.Cleanup();
        }
    }
}


Imports System.IO
Imports System.Collections.Generic
Imports System.Text
Imports System.IO.Log

Namespace MyLogRecordSequence
    Public Class MyLog
        Private logName As String = "test.log"
        Private logContainer As String = "MyExtent0"
        Private containerSize As Integer = 32 * 1024
        Private sequence As LogRecordSequence = Nothing
        Private delete As Boolean = True

        ' These are used in the TailPinned event handler.
        Public Shared MySequence As LogRecordSequence = Nothing
        Public Shared AdvanceBase As Boolean = True

        Public Sub New()
            ' Create a LogRecordSequence.
            sequence = New LogRecordSequence(Me.logName, FileMode.CreateNew, FileAccess.ReadWrite, FileShare.None)

            ' At least one container/extent must be added for Log Record Sequence.
            sequence.LogStore.Extents.Add(Me.logContainer, Me.containerSize)

            MySequence = sequence

        End Sub

        Public Sub AddExtents()
            ' Add two additional extents. The extents are 
            ' of the same size as the first extent.
            sequence.LogStore.Extents.Add("MyExtent1")
            sequence.LogStore.Extents.Add("MyExtent2")
        End Sub

        Public Sub EnumerateExtents()
            Dim store As LogStore = sequence.LogStore

            Console.WriteLine("Enumerating Log Extents...")
            Console.WriteLine("    Extent Count: {0} extents", store.Extents.Count)
            Console.WriteLine("    Extents Are...")
            For Each extent In store.Extents
                Console.WriteLine("      {0} ({1}, {2})", Path.GetFileName(extent.Path), extent.Size, extent.State)
            Next extent
            Console.WriteLine("    Free Extents: {0} Free", store.Extents.FreeCount)
        End Sub

        Public Sub SetLogPolicy()
            Console.WriteLine()
            Console.WriteLine("Setting current log policy...")

            ' SET LOG POLICY

            Dim policy As LogPolicy = sequence.LogStore.Policy

            ' Set AutoGrow policy. This enables the log to automatically grow
            ' when the existing extents are full. New extents are added until
            ' we reach the MaximumExtentCount extents.
            ' AutoGrow policy is supported only in Windows Vista and not available in R2.

            'policy.AutoGrow = true;

            ' Set the Growth Rate in terms of extents. This policy specifies
            ' "how much" the log should grow. 
            policy.GrowthRate = New PolicyUnit(2, PolicyUnitType.Extents)

            ' Set the AutoShrink policy. This enables the log to automatically
            ' shrink if the available free space exceeds the shrink percentage. 
            ' AutoGrow/shrink policy is supported only in Windows Vista and not available in R2.

            'policy.AutoShrinkPercentage = new PolicyUnit(30, PolicyUnitType.Percentage);

            ' Set the PinnedTailThreshold policy.
            ' A tail pinned event is triggered when there is no
            ' log space available and log space may be freed by advancing the base.
            ' The user must handle the tail pinned event by advancing the base of the log. 
            ' If the user is not able to move the base of the log, the user should report with exception in
            ' the tail pinned handler.
            ' PinnedTailThreashold policy dictates the amount of space that the TailPinned event requests 
            ' for advancing the base of the log. The amount of space can be in percentage or in terms of bytes 
            ' which is rounded off to the nearest containers in CLFS. The default is 35 percent.


            policy.PinnedTailThreshold = New PolicyUnit(10, PolicyUnitType.Percentage)

            ' Set the maximum extents the log can have.
            policy.MaximumExtentCount = 6

            ' Set the minimum extents the log can have.
            policy.MinimumExtentCount = 2

            ' Set the prefix for new containers that are added. 
            ' when AutoGrow is enabled.
            'policy.NewExtentPrefix = "MyLogPrefix";

            ' Set the suffix number for new containers that are added.
            ' when AutoGrow is enabled. 
            policy.NextExtentSuffix = 3

            ' Commit the log policy.
            policy.Commit()

            ' Refresh updates the IO.Log policy properties with current log policy 
            ' set in the log. 
            policy.Refresh()

            ' LOG POLICY END
            ' 

            '+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
            ' Setting up IO.Log provided capabilities...
            ' 

            ' SET RETRY APPEND

            ' IO.Log provides a mechanism similar to AutoGrow.
            ' If the existing log is full and an append fails, setting RetryAppend
            ' invokes the CLFS policy engine to add new extents and re-tries
            ' record appends. If MaximumExtent count has been reached, 
            ' a SequenceFullException is thrown. 
            ' 

            sequence.RetryAppend = True

            ' RETRY APPEND END

            ' REGISTER FOR TAILPINNED EVENT NOTIFICATIONS

            ' Register for TailPinned Event by passing in an event handler.
            ' An event is raised when the log full condition is reached.
            ' The user should either advance the base sequence number to the 
            ' nearest valid sequence number recommended in the tail pinned event or
            ' report a failure that it is not able to advance the base sequence 
            ' number. 
            '

            AddHandler sequence.TailPinned, AddressOf HandleTailPinned

            Console.WriteLine("Done...")
        End Sub

        Public Sub ShowLogPolicy()
            Console.WriteLine()
            Console.WriteLine("Showing current log policy...")

            Dim policy As LogPolicy = sequence.LogStore.Policy

            Console.WriteLine("    Minimum extent count:  {0}", policy.MinimumExtentCount)
            Console.WriteLine("    Maximum extent count:  {0}", policy.MaximumExtentCount)
            Console.WriteLine("    Growth rate:           {0}", policy.GrowthRate)
            Console.WriteLine("    Pinned tail threshold: {0}", policy.PinnedTailThreshold)
            Console.WriteLine("    Auto shrink percent:   {0}", policy.AutoShrinkPercentage)
            Console.WriteLine("    Auto grow enabled:     {0}", policy.AutoGrow)
            Console.WriteLine("    New extent prefix:     {0}", policy.NewExtentPrefix)
            Console.WriteLine("    Next extent suffix:    {0}", policy.NextExtentSuffix)

        End Sub

        ' Append records. Appending three records.  
        Public Sub AppendRecords()
            Console.WriteLine("Appending Log Records...")
            Dim previous As SequenceNumber = SequenceNumber.Invalid

            previous = sequence.Append(CreateData("Hello World!"), SequenceNumber.Invalid, SequenceNumber.Invalid, RecordAppendOptions.ForceFlush)
            previous = sequence.Append(CreateData("This is my first Logging App"), SequenceNumber.Invalid, SequenceNumber.Invalid, RecordAppendOptions.ForceFlush)
            previous = sequence.Append(CreateData("Using LogRecordSequence..."), SequenceNumber.Invalid, SequenceNumber.Invalid, RecordAppendOptions.ForceFlush)

            Console.WriteLine("Done...")
        End Sub


        ' Read the records added to the log. 
        Public Sub ReadRecords()
            Dim enc As Encoding = Encoding.Unicode

            Console.WriteLine()

            Console.WriteLine("Reading Log Records...")
            Try
                For Each record As LogRecord In Me.sequence.ReadLogRecords(Me.sequence.BaseSequenceNumber, LogRecordEnumeratorType.Next)
                    Dim data(record.Data.Length - 1) As Byte
                    record.Data.Read(data, 0, CInt(Fix(record.Data.Length)))
                    Dim mystr As String = enc.GetString(data)
                    Console.WriteLine("    {0}", mystr)
                Next record
            Catch e As Exception
                Console.WriteLine("Exception {0} {1}", e.GetType(), e.Message)
            End Try

            Console.WriteLine()
        End Sub

        Public Sub FillLog()
            Dim append As Boolean = True

            Do While append
                Try
                    sequence.Append(CreateData(16 * 1024), SequenceNumber.Invalid, SequenceNumber.Invalid, RecordAppendOptions.ForceFlush)

                Catch e1 As SequenceFullException
                    Console.WriteLine("Log is Full...")
                    append = False
                End Try
            Loop
        End Sub

        ' Dispose the record sequence and delete the log file. 
        Public Sub Cleanup()
            ' Dispose the sequence
            sequence.Dispose()

            ' Delete the log file.
            If delete Then
                Try
                    ' This deletes the base log file and all the extents associated with the log.
                    LogStore.Delete(Me.logName)
                Catch e As Exception
                    Console.WriteLine("Exception {0} {1}", e.GetType(), e.Message)
                End Try
            End If
        End Sub

        ' Converts the given data to an Array of ArraySegment<byte> 
        Public Shared Function CreateData(ByVal str As String) As IList(Of ArraySegment(Of Byte))
            Dim enc As Encoding = Encoding.Unicode

            Dim array() As Byte = enc.GetBytes(str)

            Dim segments(0) As ArraySegment(Of Byte)
            segments(0) = New ArraySegment(Of Byte)(array)

            Return System.Array.AsReadOnly(Of ArraySegment(Of Byte))(segments)
        End Function

        Public Shared Function CreateData(ByVal size As Integer) As IList(Of ArraySegment(Of Byte))
            Dim array(size - 1) As Byte

            Dim rand As New Random()
            rand.NextBytes(array)

            Dim segments(0) As ArraySegment(Of Byte)
            segments(0) = New ArraySegment(Of Byte)(array)

            Return System.Array.AsReadOnly(Of ArraySegment(Of Byte))(segments)
        End Function

        Public Shared Function GetAdvanceBaseSeqNumber(ByVal recTargetSeqNum As SequenceNumber) As SequenceNumber
            Dim targetSequenceNumber As SequenceNumber = SequenceNumber.Invalid

            Console.WriteLine("Getting actual target sequence number...")

            ' 
            ' Implement the logic for returning a valid sequence number closer to
            ' recommended target sequence number. 
            '

            Return targetSequenceNumber
        End Function

        Public Shared Sub HandleTailPinned(ByVal arg As Object, ByVal tailPinnedEventArgs As TailPinnedEventArgs)
            Console.WriteLine("TailPinned has fired")

            ' Based on the implementation of a logging application, the log base can be moved
            ' to free up more log space and if it is not possible to move the 
            ' base, the application should report by throwing an exception.

            If MyLog.AdvanceBase Then
                Try
                    ' TailPnnedEventArgs has the recommended sequence number and its generated 
                    ' based on PinnedTailThreshold policy. 
                    ' This does not map to an actual sequence number in the record sequence
                    ' but an approximation and potentially frees up the threshold % log space
                    ' when the log base is advanced to a valid sequence number closer to the 
                    ' recommended sequence number. 
                    ' The user should use this sequence number to locate a closest valid sequence
                    ' number to advance the base of the log.

                    Dim recommendedTargetSeqNum As SequenceNumber = tailPinnedEventArgs.TargetSequenceNumber

                    ' Get the actual Target sequence number.
                    Dim actualTargetSeqNum As SequenceNumber = MyLog.GetAdvanceBaseSeqNumber(recommendedTargetSeqNum)

                    MySequence.AdvanceBaseSequenceNumber(actualTargetSeqNum)
                Catch e As Exception
                    Console.WriteLine("Exception thrown {0} {1}", e.GetType(), e.Message)
                End Try
            Else
                ' Report back Error if under some conditions the log cannot
                ' advance the base sequence number.

                Console.WriteLine("Reporting Error! Unable to move the base sequence number!")
                Throw New IOException()
            End If
        End Sub
    End Class

    Friend Class LogSample
        Shared Sub Main(ByVal args() As String)
            ' Create log record sequence.
            Dim log As New MyLog()

            ' Add additional extents.
            log.AddExtents()

            ' Enumerate the current log extents.
            log.EnumerateExtents()

            ' Set log policies and register for TailPinned event notifications. 
            log.SetLogPolicy()

            log.ShowLogPolicy()

            ' Append a few records and read the appended records. 
            log.AppendRecords()
            log.ReadRecords()

            ' Fill the Log to trigger log growth...and subsequent TailPinned notifications.
            log.FillLog()

            log.EnumerateExtents()

            log.Cleanup()
        End Sub
    End Class
End Namespace

Commenti

La classe LogRecordSequence fornisce un'implementazione dell'interfaccia della sequenza di record all'inizio di un log Common Log File System (CLFS).The LogRecordSequence class provides an implementation of the record sequence interface on top of a Common Log File System (CLFS) log. Oltre alle funzionalità standard orientate al record, fornisce un modello di criteri che consente di evitare condizioni di log pieno e il multiplexing dei client sullo stesso file fisico.In addition to the standard record-oriented features, it provides a policy model for avoiding log-full conditions, and multiplexing of clients on the same physical file. Questa classe viene utilizzata insieme alla classe LogStore che fornisce un'interfaccia per la modifica e la gestione diretta di un file di log CLFS.It works with the LogStore class, which provides an interface for directly manipulating and managing a CLFS log file. La relazione tra la classe LogStore e la classe LogRecordSequence è simile alla relazione tra un file del disco e un oggetto FileStream.The relationship between the LogStore class and the LogRecordSequence class is similar to the relationship between a disk file and a FileStream object. Il file del disco fornisce l'archivio concreto e dispone di attributi quali la lunghezza e l'ora dell'ultimo accesso, mentre l'oggetto FileStream fornisce una visualizzazione del file che può essere utilizzata per operazioni di lettura o scrittura su di esso.The disk file provides the concrete storage, and has attributes such as length and last access time; while the FileStream object provides a view on the file that can be used to read from it and write to it. Analogamente, la classe LogStore dispone di attributi quali i criteri e una raccolta di extent del disco e la classe LogRecordSequence fornisce un meccanismo orientato ai record per la lettura e la scrittura di dati.Similarly, the LogStore class has attributes like a policy and a collection of disk extents; and the LogRecordSequence class provides a record-oriented mechanism for reading and writing data.

Costruttori

LogRecordSequence(LogStore)

Inizializza una nuova istanza della classe LogRecordSequence con l'archivio dei log specificato.Initializes a new instance of the LogRecordSequence class with the specified log store.

LogRecordSequence(LogStore, Int32, Int32)

Inizializza una nuova istanza della classe LogRecordSequence con l'archivio di log, la dimensione del buffer per ogni record e il numero di buffer specificati.Initializes a new instance of the LogRecordSequence class with the specified log store, buffer size for each record, and buffer number.

LogRecordSequence(String, FileMode)

Inizializza una nuova istanza della classe LogRecordSequence con il percorso all'archivio di log e la modalità di accesso specificati.Initializes a new instance of the LogRecordSequence class with a specified path to the log store and the access mode.

LogRecordSequence(String, FileMode, FileAccess)

Inizializza una nuova istanza della classe LogRecordSequence con il percorso all'archivio di log e la modalità di accesso e condivisione specificati.Initializes a new instance of the LogRecordSequence class with a specified path to the log store and the access and share modes.

LogRecordSequence(String, FileMode, FileAccess, FileShare)

Inizializza una nuova istanza della classe LogRecordSequence con il percorso all'archivio di log e la modalità di accesso specificati.Initializes a new instance of the LogRecordSequence class with a specified path to the log store and the access mode.

LogRecordSequence(String, FileMode, FileAccess, FileShare, Int32, Int32)

Inizializza una nuova istanza della classe LogRecordSequence con il percorso all'archivio dei log, l'autorizzazione per i file, le modalità di accesso e condivisione, la dimensione del buffer e il numero di record specificati.Initializes a new instance of the LogRecordSequence class with a specified path to the log store, file permission, access and share modes, and the buffer size and count for records.

LogRecordSequence(String, FileMode, FileAccess, FileShare, Int32, Int32, FileSecurity)

Inizializza una nuova istanza della classe LogRecordSequence.Initializes a new instance of the LogRecordSequence class.

Proprietà

BaseSequenceNumber

Ottiene il numero di sequenza del primo record valido dell'oggetto LogRecordSequence corrente.Gets the sequence number of the first valid record in the current LogRecordSequence.

LastSequenceNumber

Ottiene il numero di sequenza maggiore dell'ultimo record aggiunto.Gets the sequence number which is greater than the last record appended.

LogStore

Ottiene l'oggetto LogStore che contiene i dati per questa sequenza di record.Gets the LogStore that contains the data for this record sequence. Questo metodo non può essere ereditato.This method cannot be inherited.

MaximumRecordLength

Ottiene la dimensione massima di un record che può essere aggiunto alla sequenza.Gets the maximum size of a record that can be added to this record sequence.

ReservedBytes

Ottiene il numero totale di byte che sono stati riservati.Gets the total number of bytes that have been reserved.

RestartSequenceNumber

Ottiene il numero di sequenza dell'area di riavvio più vicina alla fine del log.Gets the sequence number of the restart area closest to the end of the log.

RetryAppend

Ottiene o imposta un valore che indica se le operazioni di accodamento vengono ripetute automaticamente nel caso in cui il log sia pieno.Gets or sets a value indicating whether or not appends are automatically retried if the log is full.

Metodi

AdvanceBaseSequenceNumber(SequenceNumber)

Sposta in avanti il numero di sequenza di base del log.Moves the base sequence number of the log forward. Questo metodo non può essere ereditato.This method cannot be inherited.

Append(ArraySegment<Byte>, SequenceNumber, SequenceNumber, RecordAppendOptions)

Scrive un record di log in LogRecordSequence.Writes a log record to the LogRecordSequence. Questo metodo non può essere ereditato.This method cannot be inherited.

Append(ArraySegment<Byte>, SequenceNumber, SequenceNumber, RecordAppendOptions, ReservationCollection)

Accoda un record di log a IRecordSequence utilizzando spazio precedentemente riservato nella sequenza.Appends a log record to the IRecordSequence, using space previously reserved in the sequence. Questo metodo non può essere ereditato.This method cannot be inherited.

Append(IList<ArraySegment<Byte>>, SequenceNumber, SequenceNumber, RecordAppendOptions)

Aggiunge un record di log a IRecordSequence.Appends a log record to the IRecordSequence. Questo metodo non può essere ereditato.This method cannot be inherited.

Append(IList<ArraySegment<Byte>>, SequenceNumber, SequenceNumber, RecordAppendOptions, ReservationCollection)

Accoda un record di log a IRecordSequence utilizzando spazio precedentemente riservato nella sequenza.Appends a log record to the IRecordSequence, using space previously reserved in the sequence. Questo metodo non può essere ereditato.This method cannot be inherited.

BeginAppend(ArraySegment<Byte>, SequenceNumber, SequenceNumber, RecordAppendOptions, AsyncCallback, Object)

Avvia un'operazione di accodamento asincrona.Begins an asynchronous append operation. Questo metodo non può essere ereditato.This method cannot be inherited.

BeginAppend(ArraySegment<Byte>, SequenceNumber, SequenceNumber, RecordAppendOptions, ReservationCollection, AsyncCallback, Object)

Avvia un'operazione di accodamento asincrona.Begins an asynchronous append operation. Questo metodo non può essere ereditato.This method cannot be inherited.

BeginAppend(IList<ArraySegment<Byte>>, SequenceNumber, SequenceNumber, RecordAppendOptions, AsyncCallback, Object)

Avvia un'operazione di accodamento asincrona.Begins an asynchronous append operation. Questo metodo non può essere ereditato.This method cannot be inherited.

BeginAppend(IList<ArraySegment<Byte>>, SequenceNumber, SequenceNumber, RecordAppendOptions, ReservationCollection, AsyncCallback, Object)

Avvia un'operazione di accodamento asincrona.Begins an asynchronous append operation. Questo metodo non può essere ereditato.This method cannot be inherited.

BeginFlush(SequenceNumber, AsyncCallback, Object)

Avvia un'operazione di scaricamento asincrono, utilizzando spazio precedentemente riservato nella sequenza.Begins an asynchronous flush operation, using space previously reserved in the sequence. Questo metodo non può essere ereditato.This method cannot be inherited.

BeginReserveAndAppend(ArraySegment<Byte>, SequenceNumber, SequenceNumber, RecordAppendOptions, ReservationCollection, Int64[], AsyncCallback, Object)

Avvia un'operazione asincrona di prenotazione e accodamento.Begins an asynchronous reserve and append operation. Questo metodo non può essere ereditato.This method cannot be inherited.

BeginReserveAndAppend(IList<ArraySegment<Byte>>, SequenceNumber, SequenceNumber, RecordAppendOptions, ReservationCollection, Int64[], AsyncCallback, Object)

Avvia un'operazione asincrona di prenotazione e accodamento.Begins an asynchronous reserve and append operation. Questo metodo non può essere ereditato.This method cannot be inherited.

BeginWriteRestartArea(ArraySegment<Byte>, SequenceNumber, ReservationCollection, AsyncCallback, Object)

Avvia un'operazione asincrona di scrittura dell'area di riavvio utilizzando spazio precedentemente riservato nella sequenza.Begins an asynchronous restart area write operation, using space previously reserved in the sequence. Questo metodo non può essere ereditato.This method cannot be inherited.

BeginWriteRestartArea(IList<ArraySegment<Byte>>, SequenceNumber, ReservationCollection, AsyncCallback, Object)

Avvia un'operazione asincrona di scrittura dell'area di riavvio utilizzando spazio precedentemente riservato nella sequenza.Begins an asynchronous restart area write operation, using space previously reserved in the sequence. Questo metodo non può essere ereditato.This method cannot be inherited.

CreateReservationCollection()

Crea un nuovo oggetto ReservationCollection.Creates a new ReservationCollection. Questo metodo non può essere ereditato.This method cannot be inherited.

Dispose()

Rilascia le risorse utilizzate dal componente.Releases the resources used by the component.

EndAppend(IAsyncResult)

Termina un'operazione di accodamento asincrona.Ends an asynchronous append operation. Questo metodo non può essere ereditato.This method cannot be inherited.

EndFlush(IAsyncResult)

Termina un'operazione di scaricamento asincrono.Ends an asynchronous flush operation. Questo metodo non può essere ereditato.This method cannot be inherited.

EndReserveAndAppend(IAsyncResult)

Termina un'operazione asincrona di prenotazione e accodamento.Ends an asynchronous reserve and append operation. Questo metodo non può essere ereditato.This method cannot be inherited.

EndWriteRestartArea(IAsyncResult)

Termina un'operazione asincrona di scrittura dell'area di riavvio.Ends an asynchronous restart area write operation. Questo metodo non può essere ereditato.This method cannot be inherited.

Equals(Object)

Determina se l'oggetto specificato è uguale all'oggetto corrente.Determines whether the specified object is equal to the current object.

(Ereditato da Object)
Flush()

Garantisce la scrittura di tutti i record aggiunti.Ensures that all appended records have been written. Questo metodo non può essere ereditato.This method cannot be inherited.

Flush(SequenceNumber)

Garantisce che tutti i record aggiunti fino al record con il numero di sequenza specificato incluso siano stati scritti in modo durevole.Ensures that all appended records up to and including the record with the specified sequence number have been durably written. Questo metodo non può essere ereditato.This method cannot be inherited.

GetHashCode()

Funge da funzione hash predefinita.Serves as the default hash function.

(Ereditato da Object)
GetType()

Ottiene l'oggetto Type dell'istanza corrente.Gets the Type of the current instance.

(Ereditato da Object)
MemberwiseClone()

Crea una copia superficiale dell'oggetto Object corrente.Creates a shallow copy of the current Object.

(Ereditato da Object)
ReadLogRecords(SequenceNumber, LogRecordEnumeratorType)

Restituisce una raccolta enumerabile di record inclusi nella sequenza.Returns an enumerable collection of records in the sequence. Questo metodo non può essere ereditato.This method cannot be inherited.

ReadRestartAreas()

Restituisce una raccolta enumerabile delle aree di riavvio contenute nella sequenza.Returns an enumerable collection of the restart areas in the sequence. Questo metodo non può essere ereditato.This method cannot be inherited.

ReserveAndAppend(ArraySegment<Byte>, SequenceNumber, SequenceNumber, RecordAppendOptions, ReservationCollection, Int64[])

Crea automaticamente una sola prenotazione e accoda un record alla sequenza.Automatically makes a single reservation and appends a record to the sequence. Questo metodo non può essere ereditato.This method cannot be inherited.

ReserveAndAppend(IList<ArraySegment<Byte>>, SequenceNumber, SequenceNumber, RecordAppendOptions, ReservationCollection, Int64[])

Crea automaticamente una sola prenotazione e accoda un record alla sequenza.Automatically makes a single reservation and appends a record to the sequence. Questo metodo non può essere ereditato.This method cannot be inherited.

SetLastRecord(SequenceNumber)

Imposta l'ultimo record contenuto in LogRecordSequence.Sets the last record in the LogRecordSequence.

ToString()

Restituisce una stringa che rappresenta l'oggetto corrente.Returns a string that represents the current object.

(Ereditato da Object)
WriteRestartArea(ArraySegment<Byte>)

Scrive un'area di riavvio in LogRecordSequence.Writes a restart area to the LogRecordSequence. Questo metodo non può essere ereditato.This method cannot be inherited.

WriteRestartArea(ArraySegment<Byte>, SequenceNumber)

Scrive un'area di riavvio in LogRecordSequence e aggiorna il numero di sequenza di base.Writes a restart area to the LogRecordSequence and updates the base sequence number. Questo metodo non può essere ereditato.This method cannot be inherited.

WriteRestartArea(ArraySegment<Byte>, SequenceNumber, ReservationCollection)

Scrive un'area di riavvio in LogRecordSequence utilizzando una prenotazione e aggiorna il numero di sequenza di base.Writes a restart area to the LogRecordSequence using a reservation, and updates the base sequence number. Questo metodo non può essere ereditato.This method cannot be inherited.

WriteRestartArea(IList<ArraySegment<Byte>>)

Scrive un'area di riavvio in LogRecordSequence.Writes a restart area to the LogRecordSequence. Questo metodo non può essere ereditato.This method cannot be inherited.

WriteRestartArea(IList<ArraySegment<Byte>>, SequenceNumber)

Scrive un'area di riavvio in LogRecordSequence e aggiorna il numero di sequenza di base.Writes a restart area to the LogRecordSequence and updates the base sequence number. Questo metodo non può essere ereditato.This method cannot be inherited.

WriteRestartArea(IList<ArraySegment<Byte>>, SequenceNumber, ReservationCollection)

Scrive un'area di riavvio in LogRecordSequence utilizzando una prenotazione e aggiorna il numero di sequenza di base.Writes a restart area to the LogRecordSequence using a reservation, and updates the base sequence number. Questo metodo non può essere ereditato.This method cannot be inherited.

Eventi

TailPinned

Segnala l'esigenza di spostare la coda della sequenza.Signals the need to move the tail of the sequence.

Si applica a