Second Round CURL Wrapper Review

[Jonas Drewsen]

Den 03-12-2011 13:10, Vladimir Panteleev skrev:
> On Sat, 03 Dec 2011 13:53:16 +0200, Jonas Drewsen <jdrewsen at nospam.com>
> wrote:
>
>> As mentioned the async version performs the request in another thread
>> leaving the main thread available for you to do something else. I'll
>> clarify in the docs that it is when you actually call empty/front on
>> the returned range you will get data from the other thread and may be
>> blocking.
>
> I can't think of a realistic use case for the current asynchronous API.
> Basically, all you can do is start a request in the background, but
> you're neither notified of the request nor can you poll it to check its
> status? So the only thing you CAN do is ask for a request that you will
> need in the future, and when that future moment comes, block if
> necessary to get the result?

The standard example is downloading some content and saving it at the 
same time.

While your main thread saves a chunk to disk (or uploads to another 
server) the async thread is busy buffering incoming chunks of data. This 
means that you effectively only wait for the slowest of the two IO 
operations. If you did it synchronously would worst case have to wait 
for all everything to be downloaded and the wait for everything to be 
saved or uploaded.

foreach(chunk; byChunkAsync("www.abc.com/hugefile.bin"))
{
     // While writing to file in this thrad
     // new chunks are downloaded
     // in the background thread
     file.write(chunk);
}

I hope this makes sense.

/Jonas