Crate rate_limits

A crate for parsing HTTP rate limit headers as per the IETF draft. Inofficial implementations like the Github rate limit headers are also supported on a best effort basis. See vendor list for support.

use indoc::indoc;
use std::str::FromStr;
use time::{OffsetDateTime, Duration};
use rate_limits::{Vendor, RateLimit, ResetTime};

let headers = indoc! {"
    x-ratelimit-limit: 5000
    x-ratelimit-remaining: 4987
    x-ratelimit-reset: 1350085394
"};

assert_eq!(
    RateLimit::from_str(headers).unwrap(),
    RateLimit {
        limit: 5000,
        remaining: 4987,
        reset: ResetTime::DateTime(
            OffsetDateTime::from_unix_timestamp(1350085394).unwrap()
        ),
        window: Some(Duration::HOUR),
        vendor: Vendor::Github
    },
);

Also takes the Retry-After header into account when calculating the reset time.

http::HeaderMap is supported as well:

use std::str::FromStr;
use time::{OffsetDateTime, Duration};
use rate_limits::{Vendor, RateLimit, ResetTime};
use http::header::HeaderMap;

let mut headers = HeaderMap::new();
headers.insert("X-RATELIMIT-LIMIT", "5000".parse().unwrap());
headers.insert("X-RATELIMIT-REMAINING", "4987".parse().unwrap());
headers.insert("X-RATELIMIT-RESET", "1350085394".parse().unwrap());

assert_eq!(
    RateLimit::new(headers).unwrap(),
    RateLimit {
        limit: 5000,
        remaining: 4987,
        reset: ResetTime::DateTime(
            OffsetDateTime::from_unix_timestamp(1350085394).unwrap()
        ),
        window: Some(Duration::HOUR),
        vendor: Vendor::Github
    },
);

Other resources:

• Examples of HTTP API Rate Limiting HTTP Response

Structs

Limit

A rate limit header

RateLimit

HTTP rate limits as parsed from header values

RateLimitVariant

A variant defines all relevant fields for parsing headers from a given vendor

Remaining

A rate limit header for the number of remaining requests

Enums

ResetTime

Reset time of rate limiting

ResetTimeKind

The kind of rate limit reset time

Vendor

Known vendors of rate limit headers