Line data    Source code

       1              : use rand::Rng;
       2              : use rand::rngs::StdRng;
       3              : 
       4              : /// Describes random delays and failures. Delay will be uniformly distributed in [min, max].
       5              : /// Connection failure will occur with the probablity fail_prob.
       6              : #[derive(Clone, Debug)]
       7              : pub struct Delay {
       8              :     pub min: u64,
       9              :     pub max: u64,
      10              :     pub fail_prob: f64, // [0; 1]
      11              : }
      12              : 
      13              : impl Delay {
      14              :     /// Create a struct with no delay, no failures.
      15            0 :     pub fn empty() -> Delay {
      16            0 :         Delay {
      17            0 :             min: 0,
      18            0 :             max: 0,
      19            0 :             fail_prob: 0.0,
      20            0 :         }
      21            0 :     }
      22              : 
      23              :     /// Create a struct with a fixed delay.
      24            0 :     pub fn fixed(ms: u64) -> Delay {
      25            0 :         Delay {
      26            0 :             min: ms,
      27            0 :             max: ms,
      28            0 :             fail_prob: 0.0,
      29            0 :         }
      30            0 :     }
      31              : 
      32              :     /// Generate a random delay in range [min, max]. Return None if the
      33              :     /// message should be dropped.
      34       103199 :     pub fn delay(&self, rng: &mut StdRng) -> Option<u64> {
      35       103199 :         if rng.gen_bool(self.fail_prob) {
      36        14468 :             return None;
      37        88731 :         }
      38        88731 :         Some(rng.gen_range(self.min..=self.max))
      39       103199 :     }
      40              : }
      41              : 
      42              : /// Describes network settings. All network packets will be subjected to the same delays and failures.
      43              : #[derive(Clone, Debug)]
      44              : pub struct NetworkOptions {
      45              :     /// Connection will be automatically closed after this timeout if no data is received.
      46              :     pub keepalive_timeout: Option<u64>,
      47              :     /// New connections will be delayed by this amount of time.
      48              :     pub connect_delay: Delay,
      49              :     /// Each message will be delayed by this amount of time.
      50              :     pub send_delay: Delay,
      51              : }