Re: [libmicrohttpd] Handling range requests with libmicrohttpd

[Christian Grothoff]

On Tuesday 28 December 2010 23:18:43 address@hidden wrote:
> Hello,
> 
> I'm using libmicrohttpd as a streaming server that serves audio files to an
> HTML5 Audio object. It's working fine for small files, but for songs that
> are longer and have larger files, the audio object sends a range request
> and because I'm not handling the request properly, the audio object fails.
> I am using MHD_USE_THREAD_PER_CONNECTION in MHD_start_daemon(), and I
> create a response like this:
> 
> response = MHD_create_response_from_callback(sizeof(char)*fileSize, 32 *
> 1024, &file_reader, filePointer, &file_free_callback);
> 
> My file_reader is this:
> 
> static ssize_t file_reader(void *cls, uint64_t pos, char *buffer, size_t
> max) {
>     FILE *fp = (FILE*) cls;
>     (void) fseek(fp, pos, SEEK_SET);
>     return fread(buffer, 1, max, fp);
> }
> 
> When the second request comes in, the first request is still in the process
> of reading and serving the file, and I get this header:
> 
> Range: bytes=127023-
> 
> So what's the proper way of handling a range request? I'm very stuck on
> this and would appreciate any assistance. Thanks.

Simple: *you* need to parse the range request (since, presumably, you set the 
'ranges accepted' header) and then *you* simply add the offset (here 127023) to 
'pos' in your file_reader.  You can pass the connection handle (or just the 
offset) as part of a struct (which should also likely include FILE) as 'cls' to 
the file reader.

Happy hacking,

Christian
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