/// <summary>
/// 内部使用
/// </summary>
private async Task <ISharedImageMessage> InternalUploadPictureAsync(InternalSessionInfo session, UploadTarget type, Stream imgStream, bool disposeStream, CancellationToken token = default)
{
// 使用 disposeStream 目的是不使上层 caller 创建多余的状态机
if (session.ApiVersion <= new Version(1, 7, 0))
{
Guid guid = Guid.NewGuid();
MemoryStream ms = new MemoryStream(8192); // 无论如何都做一份copy
await imgStream.CopyToAsync(ms, 81920, token).ConfigureAwait(false);
ImageHttpListener.RegisterImage(guid, ms);
return(new ImageMessage(null, $"http://127.0.0.1:{ImageHttpListener.Port}/fetch?guid={guid:n}", null));
}
Stream?internalStream = null;
bool internalCreated = false;
long pervious = 0;
if (!imgStream.CanSeek || imgStream.CanTimeout) // 对于 CanTimeOut 的 imgStream, 或者无法Seek的, 一律假定其读取行为是阻塞的
// 为其创建一个内部缓存先行异步读取
{
internalStream = new MemoryStream(8192);
internalCreated = true;
await imgStream.CopyToAsync(internalStream, 81920, token);
internalStream.Seek(0, SeekOrigin.Begin);
}
else // 否则不创建副本, 避免多余的堆分配
{
internalStream = imgStream;
pervious = imgStream.Position;
}
HttpContent sessionKeyContent = new StringContent(session.SessionKey);
sessionKeyContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data")
{
Name = "sessionKey"
};
HttpContent typeContent = new StringContent(type.ToString().ToLower());
typeContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data")
{
Name = "type"
};
string format;
using SKManagedStream skstream = new SKManagedStream(internalStream, false);
using (SKCodec codec = SKCodec.Create(skstream)) // 已经把数据读到非托管内存里边了, 就不用管input的死活了
{
var skformat = codec.EncodedFormat;
format = skformat.ToString().ToLower();
switch (skformat)
{
case SKEncodedImageFormat.Gif:
case SKEncodedImageFormat.Jpeg:
case SKEncodedImageFormat.Png:
break;
default:
{
skstream.Seek(0);
using (SKBitmap bitmap = SKBitmap.Decode(skstream))
{
if (!internalCreated)
{
internalStream = new MemoryStream(8192);
internalCreated = true;
}
else
{
internalStream.Seek(0, SeekOrigin.Begin);
}
bitmap.Encode(internalStream, SKEncodedImageFormat.Png, 100);
}
format = "png";
break;
}
}
}
if (internalCreated)
{
internalStream.Seek(0, SeekOrigin.Begin);
}
else // internalStream == imgStream
{
internalStream.Seek(pervious - internalStream.Position, SeekOrigin.Current);
}
HttpContent imageContent = new StreamContent(internalStream);
imageContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data")
{
Name = "img",
FileName = $"{Guid.NewGuid():n}.{format}"
};
imageContent.Headers.ContentType = new MediaTypeHeaderValue("image/" + format);
HttpContent[] contents = new HttpContent[]
{
sessionKeyContent,
typeContent,
imageContent
};
try
{
CreateLinkedUserSessionToken(session.Token, token, out CancellationTokenSource? cts, out token);
return(await _client.PostAsync($"{_options.BaseUrl}/uploadImage", contents, token)
.AsApiRespAsync <ISharedImageMessage, ImageMessage>(token)
.DisposeWhenCompleted(cts)
.ContinueWith(t => t.IsFaulted && t.Exception !.InnerException is JsonException ? throw new NotSupportedException("当前版本的mirai-api-http无法发送图片。") : t, TaskContinuationOptions.ExecuteSynchronously).Unwrap().ConfigureAwait(false));
// ^-- 处理 JsonException 到 NotSupportedException, https://github.com/mamoe/mirai-api-http/issues/85
// internalStream 是 MemoryStream, 内部为全托管字段不需要 Dispose
}
finally
{
if (disposeStream)
{
imgStream.Dispose();
}
}
}