Merge pull request #220 from http-rs/expires

Expires

Author: yoshuawuyts

LICENSE-APACHE

@@ -176,6 +176,7 @@
    END OF TERMS AND CONDITIONS
 
    Copyright 2019 Yoshua Wuyts
+   Copyright 2016-2018 Michael Tilli (Pyfisch) & `httpdate` contributors
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.

LICENSE-MIT

@@ -3,6 +3,7 @@ The MIT License (MIT)
 Copyright (c) 2019 Yoshua Wuyts
 Copyright (c) 2017 http-rs authors
 Copyright (c) 2020 Jacob Brown
+Copyright (c) 2016-2018 Michael Tilli (Pyfisch) & `httpdate` contributors
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

src/cache/expires.rs

@@ -0,0 +1,130 @@
+use crate::headers::{HeaderName, HeaderValue, Headers, ToHeaderValues, EXPIRES};
+use crate::utils::{fmt_http_date, parse_http_date};
+
+use std::fmt::Debug;
+use std::option;
+use std::time::{Duration, SystemTime};
+
+/// HTTP `Expires` header
+///
+/// # Specifications
+///
+/// - [RFC 7234, section 5.3: Expires](https://tools.ietf.org/html/rfc7234#section-5.3)
+///
+/// # Examples
+///
+/// ```
+/// # fn main() -> http_types::Result<()> {
+/// #
+/// use http_types::Response;
+/// use http_types::cache::Expires;
+/// use std::time::{SystemTime, Duration};
+///
+/// let time = SystemTime::now() + Duration::from_secs(5 * 60);
+/// let expires = Expires::new_at(time);
+///
+/// let mut res = Response::new(200);
+/// expires.apply(&mut res);
+///
+/// let expires = Expires::from_headers(res)?.unwrap();
+///
+/// // HTTP dates only have second-precision.
+/// let elapsed = time.duration_since(expires.expiration())?;
+/// assert_eq!(elapsed.as_secs(), 0);
+/// #
+/// # Ok(()) }
+/// ```
+#[derive(Debug, Ord, PartialOrd, Eq, PartialEq)]
+pub struct Expires {
+    instant: SystemTime,
+}
+
+impl Expires {
+    /// Create a new instance of `Expires`.
+    pub fn new(dur: Duration) -> Self {
+        let instant = SystemTime::now() + dur;
+        Self { instant }
+    }
+
+    /// Create a new instance of `Expires` from secs.
+    pub fn new_at(instant: SystemTime) -> Self {
+        Self { instant }
+    }
+
+    /// Get the expiration time.
+    pub fn expiration(&self) -> SystemTime {
+        self.instant
+    }
+
+    /// Create an instance of `Expires` from a `Headers` instance.
+    pub fn from_headers(headers: impl AsRef<Headers>) -> crate::Result<Option<Self>> {
+        let headers = match headers.as_ref().get(EXPIRES) {
+            Some(headers) => headers,
+            None => return Ok(None),
+        };
+
+        // If we successfully parsed the header then there's always at least one
+        // entry. We want the last entry.
+        let header = headers.iter().last().unwrap();
+
+        let instant = parse_http_date(header.as_str())?;
+        Ok(Some(Self { instant }))
+    }
+
+    /// Insert a `HeaderName` + `HeaderValue` pair into a `Headers` instance.
+    pub fn apply(&self, mut headers: impl AsMut<Headers>) {
+        headers.as_mut().insert(EXPIRES, self.value());
+    }
+
+    /// Get the `HeaderName`.
+    pub fn name(&self) -> HeaderName {
+        EXPIRES
+    }
+
+    /// Get the `HeaderValue`.
+    pub fn value(&self) -> HeaderValue {
+        let output = fmt_http_date(self.instant);
+
+        // SAFETY: the internal string is validated to be ASCII.
+        unsafe { HeaderValue::from_bytes_unchecked(output.into()) }
+    }
+}
+
+impl ToHeaderValues for Expires {
+    type Iter = option::IntoIter<HeaderValue>;
+    fn to_header_values(&self) -> crate::Result<Self::Iter> {
+        // A HeaderValue will always convert into itself.
+        Ok(self.value().to_header_values().unwrap())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::headers::Headers;
+
+    #[test]
+    fn smoke() -> crate::Result<()> {
+        let time = SystemTime::now() + Duration::from_secs(5 * 60);
+        let expires = Expires::new_at(time);
+
+        let mut headers = Headers::new();
+        expires.apply(&mut headers);
+
+        let expires = Expires::from_headers(headers)?.unwrap();
+
+        // HTTP dates only have second-precision
+        let elapsed = time.duration_since(expires.expiration())?;
+        assert_eq!(elapsed.as_secs(), 0);
+        Ok(())
+    }
+
+    #[test]
+    fn bad_request_on_parse_error() -> crate::Result<()> {
+        let mut headers = Headers::new();
+        headers.insert(EXPIRES, "<nori ate the tag. yum.>");
+        let err = Expires::from_headers(headers).unwrap_err();
+        assert_eq!(err.status(), 400);
+        Ok(())
+    }
+}

src/cache/mod.rs

@@ -10,7 +10,9 @@
 
 mod age;
 mod cache_control;
+mod expires;
 
 pub use age::Age;
 pub use cache_control::CacheControl;
 pub use cache_control::CacheDirective;
+pub use expires::Expires;