vibe.d: How to get the conent of a file upload ?

[Steven Schveighoffer]

On 9/17/20 1:08 PM, wjoe wrote:
> Every post or example I found copies the file, like your code does, too. 
> Why is that ? The content of the file upload is embedded in the form 
> data. There's no need for temporary files or copying at all.
> 
> On top of that, if I upload a file to a server which is on a different 
> PC on a different file system, how am I supposed to read the file from 
> disk on a remote file system ?
> 
> This makes no sense.
> 
> What I want is something like this:
> 
>> ~$ cat /var/log/temperatures.log
>>
>> temp_1=22;temp_2=28
>> temp_1=21;temp_2=25
> 
> 
>> ~$ curl -F "temperature_log=@/var/log/temperatures.log" 
>> 192.168.1.1:20222/temperature_upload
> 
>> ~$ nc -l 127.0.0.1 20222
>>
>> POST /temperature_upload HTTP/1.1
>> Host: 192.168.1.1:20222
>> User-Agent: curl/7.72.0
>> Accept: */*
>> Content-Length: 245
>> Content-Type: multipart/form-data; 
>> boundary=------------------------c73c71472ff9e7d5
>>
>> --------------------------c73c71472ff9e7d5
>> Content-Disposition: form-data; name="temperature_log"; 
>> filename="/var/log/temperatures.log"
>> Content-Type: application/octet-stream
>>
>> temp_1=22;temp_2=28
>> temp_1=21;temp_2=25
>>
>> --------------------------c73c71472ff9e7d5--
> 
> 
> void upload(HttpRequest.. req, blah)
> {
>     auto file = "temperature_log" in req.files;
>     if (file) {
>        string temp_data_raw = file.data;
>        assert ("temp_1=22;temp_2=28\ntemp_1=21;temp_2=25" == 
> temp_data_raw);
>     }
> }
> 

the `files` property actually does the processing only when you call it.

If you access the `bodyReader` property directly, you can process that 
data yourself. You can even register a web interface function with an 
`InputStream` parameter type, and it will be bound to the body data.

I've done this with my REST interface, though that's not form data.

That's not a great API, though. I would love to see vibe.d allow a 
direct call to vibe.inet.webform.parseFormData with a specific handler 
for files and form data.

I think you can agree that it's not feasible to store arbitrary sized 
file contents in memory. But it certainly can provide a mechanism to 
handle it as it's read.

-Steve