/// <summary>
/// 接收文件、保存记录
/// </summary>
/// <param name="p_section"></param>
/// <returns></returns>
async Task <FileDesc> ReceiveFile(FileMultipartSection p_section)
{
FileDesc desc = new FileDesc();
desc.ID = Kit.NewID;
desc.Name = p_section.FileName;
if (long.TryParse(_context.Request.Headers["uid"], out var id))
{
desc.Uploader = id;
}
desc.Info = p_section.Name;
// 扩展名
int pt = desc.Name.LastIndexOf('.');
string ext = pt > -1 ? desc.Name.Substring(pt).ToLower() : "";
// 根据文件名获取两级目录
string dir = GetDir(desc.Name);
desc.Path = Path.Combine(_volume, dir, desc.ID + ext).Replace('\\', '/');
EnsurePathExist(dir);
string fullPath = Path.Combine(Cfg.Root, _volume, dir, desc.ID + ext);
_result.Add(desc.Path);
try
{
using (var writeStream = File.Create(fullPath))
{
// FileStream 类型为 MultipartReaderStream
await p_section.FileStream.CopyToAsync(writeStream, _bufferSize, _context.RequestAborted);
desc.Size = writeStream.Length;
}
await _db.Exec("上传文件", desc);
}
catch
{
FileInfo fi = new FileInfo(fullPath);
if (fi.Exists)
{
try
{
fi.Delete();
}
catch { }
}
throw;
}
return(desc);
}
/************************ Section 结构 ************************
* Content-Length: 60408
* Content-Type:multipart/form-data; boundary=ZnGpDtePMx0KrHh_G0X99Yef9r8JZsRJSXC
*
* --ZnGpDtePMx0KrHh_G0X99Yef9r8JZsRJSXC
* Content-Disposition: form-data; name="fixedvolume"
*
* photo
* --ZnGpDtePMx0KrHh_G0X99Yef9r8JZsRJSXC
* Content-Disposition: form-data;name="72 x 72 (.png)"; filename="photo.jpg"
* Content-Type: application/octet-stream
* Content-Transfer-Encoding: binary
*
* ... binary data of the jpg ...
* --ZnGpDtePMx0KrHh_G0X99Yef9r8JZsRJSXC
* Content-Disposition: form-data;name="thumbnail"; filename="thumbnail.jpg"
* Content-Type: application/octet-stream
* Content-Transfer-Encoding: binary
*
* ... binary data of the jpg ...
* --ZnGpDtePMx0KrHh_G0X99Yef9r8JZsRJSXC
* Content-Disposition: form-data;name="00:00:06 (480 x 288)"; filename="ImageStabilization.wmv"
* Content-Type: application/octet-stream
* Content-Transfer-Encoding: binary
*
* ... binary data ...
* --ZnGpDtePMx0KrHh_G0X99Yef9r8JZsRJSXC--
****************************/
public async Task Handle()
{
// 读取boundary
var boundary = _context.Request.GetMultipartBoundary();
if (string.IsNullOrEmpty(boundary))
{
// 不支持的媒体类型
_context.Response.StatusCode = 415;
Log.Information("无Boundary，上传失败");
return;
}
SortedSetCache cache = null;
_db = new MySqlAccess(false);
// 记录已成功接收的文件，以备后续异常时删除这些文件
List <FileDesc> sucFiles = new List <FileDesc>();
try
{
var reader = new MultipartReader(boundary, _context.Request.Body);
var section = await reader.ReadNextSectionAsync(_context.RequestAborted);
var fmSection = section.AsFormDataSection();
if (fmSection != null && fmSection.Name == "fixedvolume")
{
// 选择固定卷
_volume = (await fmSection.GetValueAsync()).ToLower();
if (!Cfg.FixedVolumes.Contains(_volume))
{
// 无此固定卷，状态码：未满足前提条件
_context.Response.StatusCode = 412;
Log.Information("不存在固定卷 {0}，上传失败！", _volume);
return;
}
section = await reader.ReadNextSectionAsync(_context.RequestAborted);
}
else
{
// 选择正在使用数最低的卷
cache = new SortedSetCache(Cfg.VolumeKey);
_volume = await cache.GetMin();
// 该卷使用数加1
await cache.Increment(_volume);
}
// Section顺序：固定路径(可无)，文件，文件，缩略图，文件
// 缩略图由客户端生成，因提取视频帧耗资源，属于前面的文件
FileDesc lastFile = null;
while (section != null)
{
var fileSection = section.AsFileSection();
if (fileSection != null)
{
if (fileSection.Name == "thumbnail")
{
if (lastFile != null)
{
// 将缩略图复制到同路径
// 命名规则：原文件名添加后缀"-t.jpg"，如 143203944767549440.wmv-t.jpg
string fullPath = Path.Combine(Cfg.Root, lastFile.Path + Cfg.ThumbPostfix);
try
{
using (var writeStream = File.Create(fullPath))
{
await fileSection.FileStream.CopyToAsync(writeStream, _bufferSize, _context.RequestAborted);
}
}
catch { }
lastFile = null;
}
}
else
{
lastFile = await ReceiveFile(fileSection);
sucFiles.Add(lastFile);
}
}
section = await reader.ReadNextSectionAsync(_context.RequestAborted);
}
}
catch (Exception ex)
{
Log.Error(ex, "处理上传文件异常");
_result.Clear();
if (sucFiles.Count > 0)
{
// 删除已上传成功的文件和记录
StringBuilder sb = new StringBuilder();
foreach (var desc in sucFiles)
{
FileInfo fi = new FileInfo(Path.Combine(Cfg.Root, desc.Path));
if (fi.Exists)
{
try
{
fi.Delete();
}
catch { }
}
sb.Append(',');
sb.Append(desc.ID);
}
try
{
await _db.Exec($"delete from fsm_file where id in ({sb.ToString().TrimStart(',')})");
}
catch { }
}
}
finally
{
await _db.Close(true);
// 卷使用数减1
if (cache != null)
{
await cache.Decrement(_volume);
}
}
await Response();
}
