FileStreamResult 無法識別 Asp.Net Core 2.2 中的多個 http 范圍

Question

我有這樣簡單的端點：

[HttpGet]
public IActionResult GetFileDirect()
{
     var path = ...; // path to the file
     return File(System.IO.File.OpenRead(path), "text/plain", true);
}

目前文件內容：

abcdefghijklmnopqrstuvwxyz

正如您在 return 語句中看到的那樣，我為enableRangeProcessing傳遞了true 。 在單范圍請求的情況下，它可以按預期工作：

curl -H Range:bytes=0-8 http://localhost:65318/api/File -i

這是回應：

HTTP/1.1 206 Partial Content
Content-Length: 9
Content-Type: text/plain
Content-Range: bytes 0-8/26
Accept-Ranges: bytes
Server: Kestrel
X-SourceFiles: =?UTF-8?B?QzpcVXNlcnNcY2ViaXlcRGVza3RvcFxSYW5nZVdlYlxSYW5nZVdlYlxhcGlcRmlsZQ==?=
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Date: Sat, 02 Nov 2019 17:46:49 GMT

abcdefghi

但是，在多范圍請求的情況下，它不會考慮任何范圍，並會返回帶有文件全部內容的Ok響應：

curl -H  Range:bytes=0-8,12-15 http://localhost:65318/api/File -i

這是回應：

HTTP/1.1 200 OK
Content-Length: 26
Content-Type: text/plain
Accept-Ranges: bytes
Server: Kestrel
X-SourceFiles: =?UTF-8?B?QzpcVXNlcnNcY2ViaXlcRGVza3RvcFxSYW5nZVdlYlxSYW5nZVdlYlxhcGlcRmlsZQ==?=
X-Powered-By: ASP.NET
Date: Sat, 02 Nov 2019 17:49:37 GMT

abcdefghijklmnopqrstuvwxyz

Answer 1

我深入研究了比@Nkosi 更深的源代碼，以找到解析范圍的位置，請查看AspNetCore - RangeHelper.cs

if (rawRangeHeader.Count > 1 || rawRangeHeader[0].IndexOf(',') >= 0)
{
    logger.LogDebug("Multiple ranges are not supported.");

    // The spec allows for multiple ranges but we choose not to support them because the client may request
    // very strange ranges (e.g. each byte separately, overlapping ranges, etc.) that could negatively
    // impact the server. Ignore the header and serve the response normally.               
    return (false, null);
}