google_maps/request_rate/
api_rate_limit.rs

1use crate::request_rate::api_rate::ApiRate; // use crate::request_rate
2
3impl ApiRate {
4    /// This method is not for public consumption. It is for internal use only.
5    ///
6    /// ## Description
7    ///
8    /// This method does the actual rate limiting for an API.
9    /// If the current rate exceeds the targeted rate,
10    /// this method will put the thread to sleep until it is ready for the next
11    /// request.
12    pub async fn limit(&self) {
13        if let Some(wait_pool) = &self.throttle_pool { wait_pool.queue().await }
14        /*
15        match self.current_rate.first_request {
16            // If this is the first request to the API, initialize the
17            // timer.
18            None => {
19                // For some reason this trace! macro can cause a stack
20                // overflow, so it has been commented out for now:
21                /* trace!("Rate limiting is enabled for the `{}` API. First request.", api.to_string()); */
22                self.current_rate.first_request = Some(Instant::now());
23                self.current_rate.request_count = 1;
24
25                //let throttle_rate = ThrottleRate::new(self.target_rate.requests as usize,  self.target_rate.duration);
26                //self.throttle_pool = Some(ThrottlePool::new(throttle_rate));
27            } // case
28
29            // If this is not the first request - calculate the elapsed,
30            // time & current rate, compare against the target rate, and
31            // sleep if necessary:
32            Some(_first_request) => {
33                // Output logging information:
34                // For some reason these trace! macros can cause a
35                // stack overflow, so they have been commented out for
36                // now:
37                /* trace!(
38                    "{} requests to the `{}` API this session. This API's session began {} ago.",
39                    rate.current_rate.request_count,
40                    api.to_string(),
41                    duration_to_string(&first_request.elapsed())
42                ); */
43                /* trace!(
44                    "Current rate: {}. Target rate: {}.",
45                    rate.current_rate, rate.target_rate
46                ); */
47
48                // Calculate the current rate and target rate:
49                //let target_rate = rate.target_rate.requests as f64
50                //    / rate.target_rate.duration.as_secs_f64();
51                //let current_rate = rate.current_rate.request_count as f64
52                //    / first_request.elapsed().as_secs_f64();
53
54                // If the current rate exceeds the targeted rate, put
55                // the thread to sleep:
56                /*
57                let difference = current_rate - target_rate;
58                if difference > 0.0 {
59                    let sleep_duration = std::time::Duration::from_secs(
60                        ((1.0 / target_rate) + difference).round() as u64,
61                    );
62                    info!(
63                        "Thread is sleeping for {}.",
64                        duration_to_string(&sleep_duration)
65                    );
66                    std::thread::sleep(sleep_duration);
67                } // if
68
69                 */
70                // wait for throttle
71                match &self.throttle_pool {
72                    Some(wait_pool) => wait_pool.queue().await,
73                    None => ()
74                }
75
76                // Increment the request counter:
77                self.current_rate.request_count += 1;
78            } // case
79        } // match
80        */
81    } // fn
82} // impl
google_maps/request_rate/api_rate_limit.rs

google_maps/request_rate/
api_rate_limit.rs
