/// <summary>
/// 获取该文件保存的所有版本信息
/// </summary>
/// <param name="breakMatch">终止读取版本信息的判断</param>
/// <returns></returns>
public VersionSnippet[] GetAllVersionsWithBreak(Predicate <VersionSnippet> breakMatch)
{
List <VersionSnippet> vers = new List <VersionSnippet>();
uint tVer = GetMaxVersion(_internalReader); //最后修改版本
_internalReader.BaseStream.Seek(NEXT_WRITEINDEX_OFFSET + 5, SeekOrigin.Begin); //第一个版本索引位置
uint cVer = _internalReader.ReadUInt32();
VersionSnippet snippet;
bool midBreaked = false;
while (cVer != tVer)
{
snippet = new VersionSnippet();
snippet.Version = cVer;
snippet.CreateTimeUTC = DateTime.FromBinary(_internalReader.ReadInt64());
snippet.StoreIndex = _internalReader.ReadInt64();
snippet.FileLength = _internalReader.ReadInt64();
vers.Add(snippet);
if (breakMatch != null && breakMatch(snippet))
{
midBreaked = true;
break;
}
cVer = _internalReader.ReadUInt32();
}
if (cVer == tVer && midBreaked == false)
{
snippet = new VersionSnippet();
snippet.Version = cVer;
snippet.CreateTimeUTC = DateTime.FromBinary(_internalReader.ReadInt64());
snippet.StoreIndex = _internalReader.ReadInt64();
snippet.FileLength = _internalReader.ReadInt64();
vers.Add(snippet);
}
return(vers.ToArray());
}
/// <summary>
/// 获取指定版本的二进制字节数据
/// </summary>
/// <param name="version">文件版本</param>
/// <returns>该文件二进制字节数据，如果指定版本不存在则长度为0的字节数组。</returns>
public byte[] ReadReversion(uint ver)
{
//获取最高版本
uint maxVer = GetMaxVersion(_internalReader); //最后修改版本
int offSet = GetOffSetDat <int>(_internalReader, DATA_INDEX_OFFSET);
//Console.WriteLine("OffSET：{0}", offSet);
long fIdx = 0, fLen = 0;
if (ver == 0 || ver >= maxVer)
{
//最高版本数据的数据长度
_internalReader.BaseStream.Seek((long)(LASTED_VERSION_OFFSET + 4), SeekOrigin.Begin);
fLen = _internalReader.ReadInt64();
int fLenIdx = _internalReader.ReadInt32();
_internalReader.BaseStream.Seek(fLenIdx - 16, SeekOrigin.Begin);
fIdx = _internalReader.ReadInt64();
}
else
{
//当版本高于检索版本时终止
VersionSnippet[] verDat = GetAllVersionsWithBreak(spt => (spt.Version > ver));
VersionSnippet lastMV = verDat[verDat.Length - 1];
//目标版本处在大于下一小版本且小于终止版本时，获取下一小版本
if (lastMV.Version > ver && verDat.Length >= 2)
{
lastMV = verDat[verDat.Length - 2];
}
fIdx = lastMV.StoreIndex;
fLen = lastMV.FileLength;
}
fIdx += offSet;
return(base.ReadData(fIdx, (int)fLen));
}