public LpkOutputStream(Stream lpk, LpkFileInfo file)
{
this.baseStream = lpk;
this.info = file;
baseStream.Position = file.DataOffset;
gzip = new GZipStream(baseStream, CompressionMode.Decompress, true);
}
/// <summary>
/// 从压缩包解压某文件到内存
/// </summary>
/// <param name="fileName">文件名</param>
/// <param name="progress">解压进度回调对象</param>
/// <returns></returns>
public MemoryStream OpenFile(string fileName, ICodeProgress progress)
{
lock (hashTable)
{
MemoryStream ms = new MemoryStream();
fileStream.Position = hashTable[fileName];
LpkFileInfo fileInfo = new LpkFileInfo(fileStream);
fileStream.Position = fileInfo.DataOffset;
try
{
LZMA.LzmaHelper.Decompress(fileStream, ms, fileInfo.FileSize, fileInfo.UncompressedSize, progress);
}
catch (Exception ex)
{
Logger.Log.Error(ex);
throw new Exception(string.Format("File:{1} CRC({0:X}) error, file open failed!", fileInfo.CRC, fileName));
}
ms.Position = 0;
uint crc = LZMA.LzmaHelper.CRC32(ms);
if (fileInfo.CRC != crc)
{
throw new Exception(string.Format("CRC(Original:{0:X} Current:{1:X}) error, file open failed!", fileInfo.CRC, crc));
}
ms.Position = 0;
return(ms);
}
}
public LpkInputStream(Stream lpk, LpkFileInfo file)
{
this.baseStream = lpk;
this.info = file;
baseStream.Position = file.DataOffset;
gzip = new GZipStream(baseStream, CompressionMode.Compress, true);
file.FileSize = 0;
file.UncompressedSize = 0;
}
/// <summary>
/// 取得文件元信息
/// </summary>
/// <param name="name">文件名</param>
/// <returns>元信息</returns>
public LpkFileInfo GetInfo(string name)
{
fileStream.Position = hashTable[name];
LpkFileInfo info = new LpkFileInfo(fileStream)
{
Name = name
};
return(info);
}
private List <LpkFileInfo> GetInfos()
{
if (hashTable != null)
{
List <LpkFileInfo> list = new List <LpkFileInfo>();
foreach (string i in hashTable.Keys)
{
fileStream.Position = hashTable[i];
LpkFileInfo info = new LpkFileInfo(fileStream)
{
Name = i
};
list.Add(info);
}
return(list);
}
return(new List <LpkFileInfo>());
}
/// <summary>
/// 向压缩包添加文件
/// </summary>
/// <param name="fileName">文件名</param>
/// <param name="inStream">要添加的文件的流</param>
/// <param name="progress">压缩进度回调对象</param>
public void AddFile(string fileName, Stream inStream, ICodeProgress progress)
{
lock (hashTable)
{
//元信息备份缓存
byte[] metaBackup = new byte[LpkFileInfo.Size * hashTable.Count];
uint crc;
//备份老哈希表偏移
int oldHashOffset = hashOffset;
BinaryWriter bwOri = new BinaryWriter(fileStream);
uint size, uncompressedSize;
if (hashTable.ContainsKey(fileName))
{
throw new ArgumentException("A file with this name(" + fileName + ") already exists!");
}
crc = LZMA.LzmaHelper.CRC32(inStream);
inStream.Position = 0;
//取得要添加的文件的原大小
uncompressedSize = (uint)inStream.Length;
//备份压缩包原元信息
fileStream.Position = hashOffset + hashSize + 4;
fileStream.Read(metaBackup, 0, LpkFileInfo.Size * hashTable.Count);
//取得新哈希表大小
hashTable.Add(fileName, 0);
int newHashSize = HashBuffer.Length;
//压缩并写入新加文件数据
fileStream.Position = hashOffset;
LZMA.LzmaHelper.Compress(inStream, fileStream, progress);
//取得新加文件压缩后大小
size = (uint)(fileStream.Position - hashOffset);
//设置哈希表新偏移
hashOffset = (int)fileStream.Position;
//将备份的元信息写回文件，便于之后修正
fileStream.Position += (newHashSize + 4);
fileStream.Write(metaBackup, 0, metaBackup.Length);
//将哈希表新偏移写回文件
fileStream.Position = 4;
bwOri.Write(hashOffset);
//开始修正元数据
fileStream.Position = hashOffset + 4 + newHashSize;
string[] files = new string[hashTable.Count];
hashTable.Keys.CopyTo(files, 0);
foreach (string i in files)
{
LpkFileInfo info;
if (i != fileName)
{
//修正文件元数据偏移
hashTable[i] += ((hashOffset - oldHashOffset) + (newHashSize - hashSize));
fileStream.Position = hashTable[i];
info = new LpkFileInfo(fileStream)
{
HeaderOffset = (uint)hashTable[i]
};
}
else
{
//计算新文件元数据偏移
hashTable[i] = 4 + hashOffset + newHashSize + ((hashTable.Count - 1) * LpkFileInfo.Size);
info = new LpkFileInfo()
{
//计算元数据信息
HeaderOffset = (uint)hashTable[i],
DataOffset = (uint)(oldHashOffset),
UncompressedSize = uncompressedSize,
CRC = crc,
FileSize = size
};
}
//将修正后的元数据写回文件
info.WriteToStream(fileStream);
}
//将新哈希表写回文件
fileStream.Position = hashOffset;
bwOri.Write(newHashSize);
bwOri.Write(Encrypt(HashBuffer));
hashSize = newHashSize;
infoBuf = GetInfos();
}
}
