private void loadFromStream(Stream stream, string expectedContentType)
{
// TODO 流式读取尚未完成
// 增加参数，是否一次性读取
// 增加迭代器，用于流读取
// 如果是流读取，只有读取结束之时，才可以使用 Nodes 属性
var br = new BinaryReader(stream);
if (!br.ReadBytes(5).SequenceEqual(mHeaderBytes)) // 文件头
throw new InvalidDataException("指定的流不是 CPK 数据，或流位置不正确。");
if ((this.FormatVersion = br.ReadUInt16()) > FORMAT_VERSION_CODE) // 版本号
throw new NotSupportedException("不支持读取此版本的 CPK 数据（CPK 格式版本过高）");
this.Flags = (CPKFlags)br.ReadUInt32(); // 标记位
this.ContentType = CPKNode.readStringWithLength(br); // 正文类型
if (expectedContentType != null && expectedContentType != this.ContentType)
throw new InvalidDataException("输入数据的类型不是需要的类型。");
if ((this.Flags & CPKFlags.LZ4Compressed) == CPKFlags.LZ4Compressed) {
stream = new Ceeji.Data.Codec.LZ4.LZ4Stream(stream, System.IO.Compression.CompressionMode.Decompress, false, 1024 * 1024 * 30);
}
if ((this.Flags & CPKFlags.LZ4HCCompressed) == CPKFlags.LZ4HCCompressed) {
stream = new Ceeji.Data.Codec.LZ4.LZ4Stream(stream, System.IO.Compression.CompressionMode.Decompress, true, 1024 * 1024 * 30);
}
if ((this.Flags & CPKFlags.DeflateCompressed) == CPKFlags.DeflateCompressed) {
stream = new DeflateStream(stream, System.IO.Compression.CompressionMode.Decompress, true);
}
long pos = -1, pos2 = -1;
if (this.HashIncluded) {
pos = stream.Position;
}
CPKNode hashNode = null;
CPKNode node;
while ((node = CPKNode.DeserializeFromStream(stream)) != null) {
if (node.Name != "_!#hash#!_") {
if (this.HashIncluded) {
pos2 = stream.Position;
}
this.Nodes.Add(node.Name, node);
if (node.Name == "_!#guid#!_") {
this.PackageGuid = (Guid)node.Value.Value;
}
}
else {
hashNode = node;
}
}
if (this.HashIncluded) {
stream.Position = pos;
var hash = HashHelper.ComputeRawHash(new PartialReadOnlyStream(stream, pos, pos2 - pos), HashHelper.MD5Algorithm);
if (hashNode == null || !hashNode.Get<byte[]>().SequenceEqual(hash)) {
throw new InvalidDataException("指定的输入数据的数据摘要不一致，可能已经被无意间修改");
}
}
}
/// <summary>
/// 将包的内容写入指定的流。
/// </summary>
/// <param name="stream"></param>
public void WriteToStream(Stream stream)
{
if (stream == null)
throw new ArgumentNullException("stream");
// 打开流进行写入
var bw = new BinaryWriter(stream);
// 输出文件头
bw.Write(mHeaderBytes);
bw.Write(FORMAT_VERSION_CODE);
bw.Write((uint)this.Flags);
bw.Write(CPKNode.getBinaryWithLength(Encoding.UTF8.GetBytes(ContentType)));
// 输出正文
long pos = -1;
if (this.HashIncluded) {
pos = stream.Position;
}
if ((this.Flags & CPKFlags.LZ4Compressed) == CPKFlags.LZ4Compressed) {
stream.Flush();
stream = new Ceeji.Data.Codec.LZ4.LZ4Stream(stream, System.IO.Compression.CompressionMode.Compress, false, 1024 * 1024 * 30);
bw = new BinaryWriter(stream);
}
if ((this.Flags & CPKFlags.LZ4HCCompressed) == CPKFlags.LZ4HCCompressed) {
stream.Flush();
stream = new Ceeji.Data.Codec.LZ4.LZ4Stream(stream, System.IO.Compression.CompressionMode.Compress, true, 1024 * 1024 * 30);
bw = new BinaryWriter(stream);
}
if ((this.Flags & CPKFlags.DeflateCompressed) == CPKFlags.DeflateCompressed) {
stream.Flush();
stream = new DeflateStream(stream, System.IO.Compression.CompressionMode.Compress, true);
bw = new BinaryWriter(stream);
}
// var binNodes = mEmptyByteArr;
foreach (var node in this.Nodes) {
if (node.Key == "_!#hash#!_")
continue;
node.Value.SerializeToStream(stream);
//binNodes = binNodes.Concat(data).ToArray();
}
// bw.Write(binNodes);
// 如果需要哈希，则计算哈希
if (this.HashIncluded) {
long posn = stream.Position;
stream.Position = pos;
var hash = HashHelper.ComputeRawHash(stream, HashHelper.MD5Algorithm);
stream.Position = posn;
new CPKNode("_!#hash#!_", hash).SerializeToStream(stream);
}
// 输出结束符
bw.Write((byte)0);
bw.Flush();
stream.Flush();
}
