This patchset makes ProtocolServer stream the downloads to its client
(LibProtocol), and as such changes the download API; a possible
download lifecycle could be as such:
notation = client->server:'>', server->client:'<', pipe activity:'*'
```
> StartDownload(GET, url, headers, {})
< Response(0, fd 8)
* {data, 1024b}
< HeadersBecameAvailable(0, response_headers, 200)
< DownloadProgress(0, 4K, 1024)
* {data, 1024b}
* {data, 1024b}
< DownloadProgress(0, 4K, 2048)
* {data, 1024b}
< DownloadProgress(0, 4K, 1024)
< DownloadFinished(0, true, 4K)
```
Since managing the received file descriptor is a pain, LibProtocol
implements `Download::stream_into(OutputStream)`, which can be used to
stream the download into any given output stream (be it a file, or
memory, or writing stuff with a delay, etc.).
Also, as some of the users of this API require all the downloaded data
upfront, LibProtocol also implements `set_should_buffer_all_input()`,
which causes the download instance to buffer all the data until the
download is complete, and to call the `on_buffered_download_finish`
hook.
Clients now receive HTTP status codes like 200, 404, etc.
Note that a 404 with content is still considered a "successful"
download from ProtocolServer's perspective. It's up to the client
to interpret the status code.
I'm not sure if this is the best API, but it'll work for now.
Previously a download lived independently of the client connection it came
from. This was the source of several undesirable behaviours, including the
potential for clients to influence downloads they didn't start, and
downloads living longer than their associated client connections. Now we
attach downloads to client connections, which means they're cleaned up
automatically when the client goes away, and there's significantly less
risk of clients interfering with each other.
It didn't feel right to have a "DHCPClient" in a "Servers" directory.
Rename this to Services to better reflect the type of programs we'll
be putting in there.
2020-05-08 21:57:44 +02:00
Renamed from Servers/ProtocolServer/HttpsDownload.cpp (Browse further)
