Line data    Source code

       1              : use rand::{rngs::StdRng, Rng};
       2              : 
       3              : /// Describes random delays and failures. Delay will be uniformly distributed in [min, max].
       4              : /// Connection failure will occur with the probablity fail_prob.
       5              : #[derive(Clone, Debug)]
       6              : pub struct Delay {
       7              :     pub min: u64,
       8              :     pub max: u64,
       9              :     pub fail_prob: f64, // [0; 1]
      10              : }
      11              : 
      12              : impl Delay {
      13              :     /// Create a struct with no delay, no failures.
      14            0 :     pub fn empty() -> Delay {
      15            0 :         Delay {
      16            0 :             min: 0,
      17            0 :             max: 0,
      18            0 :             fail_prob: 0.0,
      19            0 :         }
      20            0 :     }
      21              : 
      22              :     /// Create a struct with a fixed delay.
      23            0 :     pub fn fixed(ms: u64) -> Delay {
      24            0 :         Delay {
      25            0 :             min: ms,
      26            0 :             max: ms,
      27            0 :             fail_prob: 0.0,
      28            0 :         }
      29            0 :     }
      30              : 
      31              :     /// Generate a random delay in range [min, max]. Return None if the
      32              :     /// message should be dropped.
      33        98933 :     pub fn delay(&self, rng: &mut StdRng) -> Option<u64> {
      34        98933 :         if rng.gen_bool(self.fail_prob) {
      35        12830 :             return None;
      36        86103 :         }
      37        86103 :         Some(rng.gen_range(self.min..=self.max))
      38        98933 :     }
      39              : }
      40              : 
      41              : /// Describes network settings. All network packets will be subjected to the same delays and failures.
      42              : #[derive(Clone, Debug)]
      43              : pub struct NetworkOptions {
      44              :     /// Connection will be automatically closed after this timeout if no data is received.
      45              :     pub keepalive_timeout: Option<u64>,
      46              :     /// New connections will be delayed by this amount of time.
      47              :     pub connect_delay: Delay,
      48              :     /// Each message will be delayed by this amount of time.
      49              :     pub send_delay: Delay,
      50              : }