private void Initialize(object file)
{
if ((ViewPageTotalSize / ViewPageCount) % this.BlockSize != 0)
{
throw new ArgumentException(string.Format("This '{0}' value of blockSize parameter is invalid.", this.BlockSize));
}
//计算缓存区总共有多少个存储块
_blockCount = (int)(StorageSize / this.BlockSize);
//计算缓存区的总大(为存储区长度+索引区长度+分配表区长度+文件头长度)
_capacity = StorageSize + (_blockCount * 4) + (36 * BufferUtility.KB) + MetadataInfo.HeadSize;
//判断传入参数是否为文件流
var fileStream = file as FileStream;
if (fileStream == null)
{
var fileInfo = new FileInfo((string)file);
if (fileInfo.Exists && fileInfo.Length > 0 && fileInfo.Length != _capacity)
{
throw new ArgumentException("file");
}
fileStream = new FileStream((string)file,
FileMode.OpenOrCreate,
FileAccess.ReadWrite,
FileShare.ReadWrite,
this.BlockSize,
FileOptions.RandomAccess);
if (fileStream.Length == 0)
{
fileStream.SetLength(_capacity);
}
}
else
{
if (fileStream.Length > 0 && fileStream.Length != _capacity)
{
throw new ArgumentException("file");
}
}
//创建内存映射文件对象
_memoryMappedFile = MemoryMappedFile.CreateFromFile(fileStream,
Path.GetFileName(fileStream.Name),
_capacity,
MemoryMappedFileAccess.ReadWrite,
null,
HandleInheritability.Inheritable,
false);
//构建默认的元数据描述对象
_metadata = MetadataInfo.Create(this.BlockSize, _blockCount);
//创建缓存页面管理器对象
_pageManager = new MemoryMappedPageManager(this, (uint)_metadata.StorageOffset);
}
internal void Kill()
{
lock (_syncRoot)
{
_pageStream.Dispose();
_pageStream = null;
_manager = null;
}
}
internal MemoryMappedPage(MemoryMappedPageManager manager, int pageIndex, Stream pageStream)
{
if (manager == null)
{
throw new ArgumentNullException("manager");
}
if (pageIndex < 0)
{
throw new ArgumentOutOfRangeException("pageIndex");
}
if (pageStream == null)
{
throw new ArgumentNullException("pageStream");
}
_syncRoot = new object();
_manager = manager;
_pageIndex = pageIndex;
_pageStream = pageStream;
}
internal MemoryMappedPage(MemoryMappedPageManager manager, int pageIndex, Stream pageStream)
{
if(manager == null)
throw new ArgumentNullException("manager");
if(pageIndex < 0)
throw new ArgumentOutOfRangeException("pageIndex");
if(pageStream == null)
throw new ArgumentNullException("pageStream");
_syncRoot = new object();
_manager = manager;
_pageIndex = pageIndex;
_pageStream = pageStream;
}
private void Initialize(object file)
{
if((ViewPageTotalSize / ViewPageCount) % this.BlockSize != 0)
throw new ArgumentException(string.Format("This '{0}' value of blockSize parameter is invalid.", this.BlockSize));
//计算缓存区总共有多少个存储块
_blockCount = (int)(StorageSize / this.BlockSize);
//计算缓存区的总大(为存储区长度+索引区长度+分配表区长度+文件头长度)
_capacity = StorageSize + (_blockCount * 4) + (36 * BufferUtility.KB) + MetadataInfo.HeadSize;
//判断传入参数是否为文件流
var fileStream = file as FileStream;
if(fileStream == null)
{
var fileInfo = new FileInfo((string)file);
if(fileInfo.Exists && fileInfo.Length > 0 && fileInfo.Length != _capacity)
throw new ArgumentException("file");
fileStream = new FileStream((string)file,
FileMode.OpenOrCreate,
FileAccess.ReadWrite,
FileShare.ReadWrite,
this.BlockSize,
FileOptions.RandomAccess);
if(fileStream.Length == 0)
fileStream.SetLength(_capacity);
}
else
{
if(fileStream.Length > 0 && fileStream.Length != _capacity)
throw new ArgumentException("file");
}
//创建内存映射文件对象
_memoryMappedFile = MemoryMappedFile.CreateFromFile(fileStream,
Path.GetFileName(fileStream.Name),
_capacity,
MemoryMappedFileAccess.ReadWrite,
null,
HandleInheritability.Inheritable,
false);
//构建默认的元数据描述对象
_metadata = MetadataInfo.Create(this.BlockSize, _blockCount);
//创建缓存页面管理器对象
_pageManager = new MemoryMappedPageManager(this, (uint)_metadata.StorageOffset);
}
internal void Kill()
{
lock(_syncRoot)
{
_pageStream.Dispose();
_pageStream = null;
_manager = null;
}
}
