public void CorrectlyRecoverSequentiallyUpdatedPage()
{
long index;
using (var fileSystemPageManager = new FileSystemPageManager(4096))
using (var storage = new Storage(fileSystemPageManager))
{
storage.OpenOrCreate(StoragePath);
var page = fileSystemPageManager.CreatePage();
index = page.Index;
}
string fileName;
using (var fileSystemPageManager = new FileSystemPageManager(4096))
using (var storage = new Storage(fileSystemPageManager))
using (var recoveryFile = new RecoveryFile(fileSystemPageManager, fileSystemPageManager.PageSize))
{
storage.OpenOrCreate(StoragePath);
var page = fileSystemPageManager.FetchPage(index);
index = page.Index;
fileSystemPageManager.Dispose();
Assert.AreEqual(index, page.Index);
Assert.AreNotEqual(0xff, page.Content[10]);
// Update twice with different bytes to make sure the latest one wins
page.Content[9] = 0xaa;
page.Content[10] = 0xaa;
recoveryFile.WriteUpdatePageRecord(page);
page.Content[10] = 0xff;
recoveryFile.WriteUpdatePageRecord(page);
recoveryFile.WriteFinalMarker();
fileName = recoveryFile.FileName;
}
Assert.True(File.Exists(fileName));
Assert.GreaterOrEqual(new FileInfo(fileName).Length, 1);
Assert.AreNotEqual(index, 0);
using (var manager = new FileSystemPageManager(4096))
using (var storage = new Storage(manager))
{
storage.OpenOrCreate(StoragePath);
var page = manager.FetchPage(index);
Assert.AreEqual(index, page.Index);
Assert.AreEqual(0xaa, page.Content[9]);
Assert.AreEqual(0xff, page.Content[10]);
}
}
/// <summary>
/// Updates a page.
/// </summary>
/// <param name="page">A page instance to update</param>
public void UpdatePage(IPage page)
{
CheckDisposed();
if (page == null)
{
throw new ArgumentNullException(nameof(page));
}
Lock();
try
{
CheckStorage();
if (_deferredUpdatesMode)
{
_recoveryFile.WriteUpdatePageRecord(page);
}
else
{
long pageAllocation = _pagemap.GetPageAllocation(page.Index);
if (pageAllocation == -1)
{
throw new PageMapException("Page is removed");
}
CheckRemovalMarker(page.Index);
_storageStream.Seek(pageAllocation, SeekOrigin.Begin);
_storageStream.Write(page.ContentCopy, 0, _pageSize);
_pagemap.Flush();
Flush(_storageStream);
}
}
finally
{
Unlock();
}
}
public void CorrectlyRecoverResurrectedPage()
{
long index;
long resurrectIndex;
using (var fileSystemPageManager = new FileSystemPageManager(4096))
using (var storage = new Storage(fileSystemPageManager))
{
storage.OpenOrCreate(StoragePath);
var page = fileSystemPageManager.CreatePage();
index = page.Index;
}
using (var fileSystemPageManager = new FileSystemPageManager(4096))
using (var storage = new Storage(fileSystemPageManager))
{
storage.OpenOrCreate(StoragePath);
var page = fileSystemPageManager.FetchPage(index);
Assert.AreEqual(index, page.Index);
Assert.AreNotEqual(0xff, page.Content[10]);
}
string fileName;
using (var fileSystemPageManager = new FileSystemPageManager(4096))
using (var storage = new Storage(fileSystemPageManager))
using (var recoveryFile = new RecoveryFile(fileSystemPageManager, fileSystemPageManager.PageSize))
{
storage.OpenOrCreate(StoragePath);
var page = fileSystemPageManager.FetchPage(index);
index = page.Index;
page.Content[10] = 0xaf;
fileSystemPageManager.RemovePage(index);
var resurrectedPage = fileSystemPageManager.CreatePage();
resurrectIndex = resurrectedPage.Index;
//check we're not going wrong way
Assert.AreEqual(index, resurrectIndex);
resurrectedPage.Content[10] = 0xff;
Assert.AreNotEqual(0xff, page.Content[10]);
fileSystemPageManager.Dispose();
recoveryFile.WriteUpdatePageRecord(page);
recoveryFile.WriteDeletePageRecord(index);
recoveryFile.WriteUpdatePageRecord(resurrectedPage);
recoveryFile.WriteFinalMarker();
fileName = recoveryFile.FileName;
}
Assert.True(File.Exists(fileName));
Assert.GreaterOrEqual(new FileInfo(fileName).Length, 1);
using (var manager = new FileSystemPageManager(4096))
using (var storage = new Storage(manager))
{
storage.OpenOrCreate(StoragePath);
var page = manager.FetchPage(index);
Assert.AreEqual(resurrectIndex, page.Index);
Assert.AreEqual(0xff, page.Content[10]);
}
}
