[FFmpeg-devel] [PATCH 2/2] avformat/http: exponentially delay reconnection to avoid flooding the server

[Ganesh Ajjanagadde]

On Sun, Sep 6, 2015 at 1:52 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
> From: Michael Niedermayer <michael at niedermayer.cc>
>
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
>  libavformat/http.c |    7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/libavformat/http.c b/libavformat/http.c
> index aa60aef..126c7b3 100644
> --- a/libavformat/http.c
> +++ b/libavformat/http.c
> @@ -28,6 +28,7 @@
>  #include "libavutil/avassert.h"
>  #include "libavutil/avstring.h"
>  #include "libavutil/opt.h"
> +#include "libavutil/time.h"
>
>  #include "avformat.h"
>  #include "http.h"
> @@ -107,6 +108,7 @@ typedef struct HTTPContext {
>      int reconnect;
>      int reconnect_at_eof;
>      int reconnect_streamed;
> +    int reconnect_delay;
>      int listen;
>      char *resource;
>      int reply_code;
> @@ -1249,6 +1251,8 @@ static int http_read_stream(URLContext *h, uint8_t *buf, int size)
>          || (read_ret == 0 && s->reconnect_at_eof && (!h->is_streamed || s->reconnect_streamed))) {
>          int64_t target = h->is_streamed ? 0 : s->off;
>          av_log(h, AV_LOG_INFO, "Will reconnect at %"PRId64" error=%s.\n", s->off, av_err2str(read_ret));
> +        av_usleep(1000U*1000*s->reconnect_delay);
> +        s->reconnect_delay = 1 + 2*s->reconnect_delay;
>          seek_ret = http_seek_internal(h, target, SEEK_SET, 1);
>          if (seek_ret != target) {
>              av_log(h, AV_LOG_ERROR, "Failed to reconnect at %"PRId64".\n", target);
> @@ -1256,7 +1260,8 @@ static int http_read_stream(URLContext *h, uint8_t *buf, int size)
>          }
>
>          read_ret = http_buf_read(h, buf, size);
> -    }
> +    } else
> +        s->reconnect_delay = 0;
>
>      return read_ret;
>  }
> --
> 1.7.9.5

Doesn't this have overflow issues?
More precisely, are you sure this behaves correctly when the int
reconnect_delay wraps around?

>
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