Re: [PATCH] add http.maxReceiveSpeed to limit git-receive-pack receiving speed

[Xiaowen Xia <haoyurenzhuxia@gmail.com>]

> I mean "In some situations it is preferable to limit receiving speed of
> git clone/fetch due to network bandwidth constraint, otherwise other
> applications performance will suffer from degraded network performance.".
Thanks!

> Wouldn't it make sense for negative speed? Why don't just return error
> if negative speed is set?
You are right, negative speed doesn't make sense. but I prefer printf
a warning and continue work instead of returning an error, negative
speed seems not a fatal error.

> Why is there boilerplate #if #endif block for libcurl 7.15.5?
The speed limit depends on the `CURLOPT_MAX_RECV_SPEED_LARGE` provided
by libCURL, and libCURL added `CURLOPT_MAX_RECV_SPEED_LARGE` in
7.15.5: https://curl.se/changes.html#7_15_5 .

Bagas Sanjaya <bagasdotme@gmail.com> 于2021年8月19日周四 下午5:36写道：
>
> On 19/08/21 16.14, Xia XiaoWen wrote:
> > Sometimes need to limit the receive speed of git `clone/fetch`
> > because of the limited network bandwidth, otherwise will prevent
> > other applications from using the network normally.
> >
> I mean "In some situations it is preferable to limit receiving speed of
> git clone/fetch due to network bandwidth constraint, otherwise other
> applications performance will suffer from degraded network performance.".
>
> > Add `http.maxReceiveSpeed` to limit `git-receive-pack` receiving
> > speed, Can be overridden by `GIT_HTTP_MAX_RECEIVE_SPEED` eivironment
> > variable.
> >
> s/eivironment/environment/
>
> > The default is unlimited, same if the value is 0 or negative. The
> > default unit is Bytes/s, common unit suffixes of k, m, or g are supported.
> >
>
> Wouldn't it make sense for negative speed? Why don't just return error
> if negative speed is set?
>
> > this configuration is valid for `clone`, `fetch`, `pull` commands of the
> > https protocol, and only supports libcurl 7.15.5 and above.
> > ---
> >   http.c | 24 +++++++++++++++++++++++-
> >   1 file changed, 23 insertions(+), 1 deletion(-)
> >
> > diff --git a/http.c b/http.c
> > index 8119247149..12030cf3bc 100644
> > --- a/http.c
> > +++ b/http.c
> > @@ -83,6 +83,9 @@ static const char *ssl_pinnedkey;
> >   static const char *ssl_cainfo;
> >   static long curl_low_speed_limit = -1;
> >   static long curl_low_speed_time = -1;
> > +#if LIBCURL_VERSION_NUM >= 0x070f05
> > +static ssize_t curl_max_receive_speed = -1;
> > +#endif
> >   static int curl_ftp_no_epsv;
> >   static const char *curl_http_proxy;
> >   static const char *http_proxy_authmethod;
> > @@ -361,7 +364,12 @@ static int http_options(const char *var, const char *value, void *cb)
> >               curl_low_speed_time = (long)git_config_int(var, value);
> >               return 0;
> >       }
> > -
> > +#if LIBCURL_VERSION_NUM >= 0x070f05
> > +     if (!strcmp("http.maxreceivespeed", var)) {
> > +             curl_max_receive_speed = git_config_ssize_t(var, value);
> > +             return 0;
> > +     }
> > +#endif
> >       if (!strcmp("http.noepsv", var)) {
> >               curl_ftp_no_epsv = git_config_bool(var, value);
> >               return 0;
> > @@ -974,6 +982,12 @@ static CURL *get_curl_handle(void)
> >                                curl_low_speed_time);
> >       }
> >
> > +#if LIBCURL_VERSION_NUM >= 0x070f05
> > +     if (curl_max_receive_speed > 0)
> > +             curl_easy_setopt(result, CURLOPT_MAX_RECV_SPEED_LARGE,
> > +                              curl_max_receive_speed);
> > +#endif
> > +
> >       curl_easy_setopt(result, CURLOPT_MAXREDIRS, 20);
> >   #if LIBCURL_VERSION_NUM >= 0x071301
> >       curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
> > @@ -1105,6 +1119,9 @@ void http_init(struct remote *remote, const char *url, int proactive_auth)
> >   {
> >       char *low_speed_limit;
> >       char *low_speed_time;
> > +#if LIBCURL_VERSION_NUM >= 0x070f05
> > +     char *max_receive_speed;
> > +#endif
> >       char *normalized_url;
> >       struct urlmatch_config config = { STRING_LIST_INIT_DUP };
> >
> > @@ -1196,6 +1213,11 @@ void http_init(struct remote *remote, const char *url, int proactive_auth)
> >       low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
> >       if (low_speed_time != NULL)
> >               curl_low_speed_time = strtol(low_speed_time, NULL, 10);
> > +#if LIBCURL_VERSION_NUM >= 0x070f05
> > +     max_receive_speed = getenv("GIT_HTTP_MAX_RECEIVE_SPEED");
> > +     if (max_receive_speed && !git_parse_ssize_t(max_receive_speed, &curl_max_receive_speed))
> > +             warning("failed to parse GIT_HTTP_MAX_RECEIVE_SPEED: %s", max_receive_speed);
> > +#endif
> >
> >       if (curl_ssl_verify == -1)
> >               curl_ssl_verify = 1;
> >
>
> Why is there boilerplate #if #endif block for libcurl 7.15.5?
>
> --
> An old man doll... just what I always wanted! - Clara