Add conditional::IfNoneMatch

Author: yoshuawuyts

src/conditional/if_match.rs

@@ -6,7 +6,11 @@ use std::iter::Iterator;
 use std::option;
 use std::slice;
 
-/// A Match-Control header.
+/// HTTP `If-Match` header.
+///
+/// # Specifications
+///
+/// - [RFC 7232, section 3.1: If-Match](https://tools.ietf.org/html/rfc7232#section-3.1)
 ///
 /// # Examples
 ///

src/conditional/if_none_match.rs

@@ -0,0 +1,240 @@
+use crate::conditional::MatchDirective;
+use crate::headers::{HeaderName, HeaderValue, Headers, ToHeaderValues, IF_NONE_MATCH};
+
+use std::fmt::{self, Debug, Write};
+use std::iter::Iterator;
+use std::option;
+use std::slice;
+
+/// HTTP `If-None-Match` header.
+///
+/// # Specifications
+///
+/// - [RFC 7232, section 3.2: If-None-Match](https://tools.ietf.org/html/rfc7232#section-3.2)
+///
+/// # Examples
+///
+/// ```
+/// # fn main() -> http_types::Result<()> {
+/// #
+/// use http_types::Response;
+/// use http_types::conditional::{IfNoneMatch, ETag};
+///
+/// let mut entries = IfNoneMatch::new();
+/// entries.push(ETag::new("0xcafebeef".to_string()));
+/// entries.push(ETag::new("0xbeefcafe".to_string()));
+///
+/// let mut res = Response::new(200);
+/// entries.apply(&mut res);
+///
+/// let entries = IfNoneMatch::from_headers(res)?.unwrap();
+/// let mut entries = entries.iter();
+/// assert_eq!(entries.next().unwrap(), ETag::new("0xcafebeef".to_string()));
+/// assert_eq!(entries.next().unwrap(), ETag::new("0xbeefcafe".to_string()));
+/// #
+/// # Ok(()) }
+/// ```
+pub struct IfNoneMatch {
+    entries: Vec<MatchDirective>,
+}
+
+impl IfNoneMatch {
+    /// Create a new instance of `IfNoneMatch`.
+    pub fn new() -> Self {
+        Self { entries: vec![] }
+    }
+
+    /// Create a new instance from headers.
+    pub fn from_headers(headers: impl AsRef<Headers>) -> crate::Result<Option<Self>> {
+        let mut entries = vec![];
+        let headers = match headers.as_ref().get(IF_NONE_MATCH) {
+            Some(headers) => headers,
+            None => return Ok(None),
+        };
+
+        for value in headers {
+            for part in value.as_str().trim().split(',') {
+                // Try and parse a directive from a str. If the directive is
+                // unkown we skip it.
+                if let Some(entry) = MatchDirective::from_str(part)? {
+                    entries.push(entry);
+                }
+            }
+        }
+
+        Ok(Some(Self { entries }))
+    }
+
+    /// Sets the `If-None-Match` header.
+    pub fn apply(&self, mut headers: impl AsMut<Headers>) {
+        headers.as_mut().insert(IF_NONE_MATCH, self.value());
+    }
+
+    /// Get the `HeaderName`.
+    pub fn name(&self) -> HeaderName {
+        IF_NONE_MATCH
+    }
+
+    /// Get the `HeaderValue`.
+    pub fn value(&self) -> HeaderValue {
+        let mut output = String::new();
+        for (n, directive) in self.entries.iter().enumerate() {
+            let directive: HeaderValue = directive.clone().into();
+            match n {
+                0 => write!(output, "{}", directive).unwrap(),
+                _ => write!(output, ", {}", directive).unwrap(),
+            };
+        }
+
+        // SAFETY: the internal string is validated to be ASCII.
+        unsafe { HeaderValue::from_bytes_unchecked(output.into()) }
+    }
+
+    /// Push a directive into the list of entries.
+    pub fn push(&mut self, directive: impl Into<MatchDirective>) {
+        self.entries.push(directive.into());
+    }
+
+    /// An iterator visiting all server entries.
+    pub fn iter(&self) -> Iter<'_> {
+        Iter {
+            inner: self.entries.iter(),
+        }
+    }
+
+    /// An iterator visiting all server entries.
+    pub fn iter_mut(&mut self) -> IterMut<'_> {
+        IterMut {
+            inner: self.entries.iter_mut(),
+        }
+    }
+}
+
+impl IntoIterator for IfNoneMatch {
+    type Item = MatchDirective;
+    type IntoIter = IntoIter;
+
+    #[inline]
+    fn into_iter(self) -> Self::IntoIter {
+        IntoIter {
+            inner: self.entries.into_iter(),
+        }
+    }
+}
+
+impl<'a> IntoIterator for &'a IfNoneMatch {
+    type Item = &'a MatchDirective;
+    type IntoIter = Iter<'a>;
+
+    #[inline]
+    fn into_iter(self) -> Self::IntoIter {
+        self.iter()
+    }
+}
+
+impl<'a> IntoIterator for &'a mut IfNoneMatch {
+    type Item = &'a mut MatchDirective;
+    type IntoIter = IterMut<'a>;
+
+    #[inline]
+    fn into_iter(self) -> Self::IntoIter {
+        self.iter_mut()
+    }
+}
+
+/// A borrowing iterator over entries in `IfNoneMatch`.
+#[derive(Debug)]
+pub struct IntoIter {
+    inner: std::vec::IntoIter<MatchDirective>,
+}
+
+impl Iterator for IntoIter {
+    type Item = MatchDirective;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.inner.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.inner.size_hint()
+    }
+}
+
+/// A lending iterator over entries in `IfNoneMatch`.
+#[derive(Debug)]
+pub struct Iter<'a> {
+    inner: slice::Iter<'a, MatchDirective>,
+}
+
+impl<'a> Iterator for Iter<'a> {
+    type Item = &'a MatchDirective;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.inner.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.inner.size_hint()
+    }
+}
+
+/// A mutable iterator over entries in `IfNoneMatch`.
+#[derive(Debug)]
+pub struct IterMut<'a> {
+    inner: slice::IterMut<'a, MatchDirective>,
+}
+
+impl<'a> Iterator for IterMut<'a> {
+    type Item = &'a mut MatchDirective;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.inner.next()
+    }
+
+    #[inline]
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.inner.size_hint()
+    }
+}
+
+impl ToHeaderValues for IfNoneMatch {
+    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())
+    }
+}
+
+impl Debug for IfNoneMatch {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let mut list = f.debug_list();
+        for directive in &self.entries {
+            list.entry(directive);
+        }
+        list.finish()
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use crate::conditional::{ETag, IfNoneMatch};
+    use crate::Response;
+
+    #[test]
+    fn smoke() -> crate::Result<()> {
+        let mut entries = IfNoneMatch::new();
+        entries.push(ETag::new("0xcafebeef".to_string()));
+        entries.push(ETag::new("0xbeefcafe".to_string()));
+
+        let mut res = Response::new(200);
+        entries.apply(&mut res);
+
+        let entries = IfNoneMatch::from_headers(res)?.unwrap();
+        let mut entries = entries.iter();
+        assert_eq!(entries.next().unwrap(), ETag::new("0xcafebeef".to_string()));
+        assert_eq!(entries.next().unwrap(), ETag::new("0xbeefcafe".to_string()));
+        Ok(())
+    }
+}

src/conditional/match_directive.rs

@@ -1,7 +1,7 @@
 use crate::conditional::ETag;
 use crate::headers::HeaderValue;
 
-/// An HTTP `If-{None-,}Match` directive.
+/// An Entity Tag based match directive.
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum MatchDirective {
     /// An ETag.

src/conditional/mod.rs

@@ -11,13 +11,15 @@
 mod etag;
 mod if_match;
 mod if_modified_since;
+mod if_none_match;
 mod if_unmodified_since;
 mod last_modified;
 mod match_directive;
 
 pub use etag::ETag;
 pub use if_match::IfMatch;
 pub use if_modified_since::IfModifiedSince;
+pub use if_none_match::IfNoneMatch;
 pub use if_unmodified_since::IfUnmodifiedSince;
 pub use last_modified::LastModified;
 pub use match_directive::MatchDirective;