/// <summary>
/// 创建文件系统。
/// </summary>
/// <param name="fullPath">要创建的文件系统的完整路径。</param>
/// <param name="access">要创建的文件系统的访问方式。</param>
/// <param name="stream">要创建的文件系统的文件系统流。</param>
/// <param name="maxFileCount">要创建的文件系统的最大文件数量。</param>
/// <param name="maxBlockCount">要创建的文件系统的最大块数据数量。</param>
/// <returns>创建的文件系统。</returns>
public static FileSystem Create(string fullPath, FileSystemAccess access, FileSystemStream stream, int maxFileCount, int maxBlockCount)
{
if (maxFileCount <= 0)
{
throw new GameFrameworkException("Max file count is invalid.");
}
if (maxBlockCount <= 0)
{
throw new GameFrameworkException("Max block count is invalid.");
}
if (maxFileCount > maxBlockCount)
{
throw new GameFrameworkException("Max file count can not larger than max block count.");
}
FileSystem fileSystem = new FileSystem(fullPath, access, stream);
fileSystem.m_HeaderData = new HeaderData(maxFileCount, maxBlockCount);
CalcOffsets(fileSystem);
Utility.Marshal.StructureToBytes(fileSystem.m_HeaderData, HeaderDataSize, s_CachedBytes);
try
{
stream.Write(s_CachedBytes, 0, HeaderDataSize);
stream.SetLength(fileSystem.m_FileDataOffset);
return(fileSystem);
}
catch
{
fileSystem.Shutdown();
return(null);
}
}
private int AllocBlock(int length)
{
length = (int)GetUpBoundClusterOffset(length);
int lengthFound = -1;
GameFrameworkLinkedListRange <int> lengthRange = default(GameFrameworkLinkedListRange <int>);
foreach (KeyValuePair <int, GameFrameworkLinkedListRange <int> > i in m_FreeBlockIndexes)
{
if (i.Key < length)
{
continue;
}
if (lengthFound >= 0 && lengthFound < i.Key)
{
continue;
}
lengthFound = i.Key;
lengthRange = i.Value;
}
if (lengthFound >= 0)
{
if (lengthFound > length && m_BlockDatas.Count >= m_HeaderData.MaxBlockCount)
{
return(-1);
}
LinkedListNode <int> blockIndexNode = lengthRange.First;
int blockIndex = blockIndexNode.Value;
m_FreeBlockIndexes.Remove(lengthFound, blockIndex);
if (lengthFound > length)
{
BlockData blockData = m_BlockDatas[blockIndex];
m_BlockDatas[blockIndex] = new BlockData(blockData.ClusterIndex, length);
WriteBlockData(blockIndex);
int deltaLength = lengthFound - length;
int anotherBlockIndex = m_BlockDatas.Count;
BlockData anotherBlockData = new BlockData(blockData.ClusterIndex + GetUpBoundClusterCount(length), deltaLength);
m_BlockDatas.Add(anotherBlockData);
m_FreeBlockIndexes.Add(deltaLength, anotherBlockIndex);
WriteBlockData(anotherBlockIndex);
WriteHeaderData();
}
return(blockIndex);
}
else
{
if (m_BlockDatas.Count >= m_HeaderData.MaxBlockCount)
{
return(-1);
}
long fileLength = m_Stream.Length;
try
{
m_Stream.SetLength(fileLength + length);
}
catch
{
return(-1);
}
int blockIndex = m_BlockDatas.Count;
BlockData blockData = new BlockData(GetUpBoundClusterCount(fileLength), length);
m_BlockDatas.Add(blockData);
WriteBlockData(blockIndex);
WriteHeaderData();
return(blockIndex);
}
}
