limitador 0.11.0

Rate limiting library
Documentation 
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use crate::limit::{Context, Limit, Namespace};
use crate::LimitadorResult;
use serde::{Deserialize, Serialize};
use std::collections::{BTreeMap, HashMap};
use std::hash::{Hash, Hasher};
use std::sync::Arc;
use std::time::Duration;

#[derive(Eq, Clone, Debug, Serialize, Deserialize)]
pub struct Counter {
    limit: Arc<Limit>,

    set_variables: BTreeMap<String, String>,

    remaining: Option<u64>,
    expires_in: Option<Duration>,
}

impl Counter {
    pub fn new<L: Into<Arc<Limit>>>(limit: L, ctx: &Context) -> LimitadorResult<Option<Self>> {
        let limit = limit.into();
        let variables = limit.resolve_variables(ctx)?;
        match variables {
            None => Ok(None),
            Some(variables) => Ok(Some(Self {
                limit,
                set_variables: variables,
                remaining: None,
                expires_in: None,
            })),
        }
    }

    pub(super) fn resolved_vars<L: Into<Arc<Limit>>>(
        limit: L,
        set_variables: HashMap<String, String>,
    ) -> LimitadorResult<Self> {
        let limit = limit.into();
        let mut vars = set_variables;
        vars.retain(|var, _| limit.has_variable(var));

        Ok(Self {
            limit,
            set_variables: vars.into_iter().collect(),
            remaining: None,
            expires_in: None,
        })
    }

    #[cfg(any(feature = "redis_storage", feature = "disk_storage"))]
    pub(crate) fn key(&self) -> Self {
        Self {
            limit: Arc::clone(&self.limit),
            set_variables: self.set_variables.clone(),
            remaining: None,
            expires_in: None,
        }
    }

    pub fn limit(&self) -> &Limit {
        &self.limit
    }

    pub fn max_value(&self) -> u64 {
        self.limit.max_value()
    }

    pub fn update_to_limit(&mut self, limit: Arc<Limit>) -> bool {
        if limit == self.limit {
            self.limit = limit;
            return true;
        }
        false
    }

    pub fn window(&self) -> Duration {
        Duration::from_secs(self.limit.seconds())
    }

    pub fn id(&self) -> Option<&str> {
        self.limit.id()
    }

    pub fn namespace(&self) -> &Namespace {
        self.limit.namespace()
    }

    pub fn set_variables(&self) -> &BTreeMap<String, String> {
        &self.set_variables
    }

    pub fn remaining(&self) -> Option<u64> {
        self.remaining
    }

    pub fn set_remaining(&mut self, remaining: u64) {
        self.remaining = Some(remaining)
    }

    pub fn expires_in(&self) -> Option<Duration> {
        self.expires_in
    }

    pub fn set_expires_in(&mut self, duration: Duration) {
        self.expires_in = Some(duration)
    }

    pub fn is_qualified(&self) -> bool {
        !self.set_variables.is_empty()
    }

    #[cfg(feature = "disk_storage")]
    pub(crate) fn variables_for_key(&self) -> Vec<(&str, &str)> {
        let mut variables = Vec::with_capacity(self.set_variables.len());
        for (var, value) in &self.set_variables {
            variables.push((var.as_str(), value.as_str()));
        }
        variables.sort_by(|(key1, _), (key2, _)| key1.cmp(key2));
        variables
    }
}

impl Hash for Counter {
    fn hash<H: Hasher>(&self, state: &mut H) {
        self.limit.hash(state);

        self.set_variables.iter().for_each(|(k, v)| {
            k.hash(state);
            v.hash(state);
        });
    }
}

impl PartialEq for Counter {
    fn eq(&self, other: &Self) -> bool {
        self.limit == other.limit && self.set_variables == other.set_variables
    }
}

#[cfg(test)]
mod tests {
    use crate::counter::Counter;
    use crate::limit::Limit;
    use std::collections::HashMap;

    #[test]
    fn resolves_variables() {
        let var = "timestamp(ts).getHours()";
        let limit = Limit::new(
            "",
            10,
            60,
            Vec::default(),
            [var.try_into().expect("failed parsing!")],
        );
        let map = HashMap::from([("ts".to_string(), "2019-10-12T13:20:50.52Z".to_string())]);
        let ctx = map.into();
        let counter = Counter::new(limit, &ctx).expect("failed creating counter");
        assert_eq!(
            counter.unwrap().set_variables.get(var),
            Some("13".to_string()).as_ref()
        );
    }
}