Quality / QualityItem improvements (#2486)

.cargo/config.toml

@@ -5,8 +5,10 @@ lint-all = "clippy --workspace --all-features --tests --examples --bins -- -Dcli
 # lib checking
 ci-check-min = "hack --workspace check --no-default-features"
 ci-check-default = "hack --workspace check"
+ci-check-default-tests = "check --workspace --tests"
 ci-check-all-feature-powerset="hack --workspace --feature-powerset --skip=__compress,io-uring check"
 ci-check-all-feature-powerset-linux="hack --workspace --feature-powerset --skip=__compress check"
 
 # testing
+ci-doctest-default = "test --workspace --doc --no-fail-fast -- --nocapture"
 ci-doctest = "test --workspace --all-features --doc --no-fail-fast -- --nocapture"

actix-http/CHANGES.md

@@ -11,6 +11,9 @@
 * `impl Clone for ws::HandshakeError`. [#2468]
 * `#[must_use]` for `ws::Codec` to prevent subtle bugs. [#1920]
 * `impl Default ` for `ws::Codec`. [#1920]
+* `header::QualityItem::{max, min}`. [#2486]
+* `header::Quality::{MAX, MIN}`. [#2486]
+* `impl Display` for `header::Quality`. [#2486]
 
 ### Changed
 * Rename `body::BoxBody::{from_body => new}`. [#2468]
@@ -27,10 +30,13 @@
 * Remove unnecessary `MessageBody` bound on types passed to `body::AnyBody::new`. [#2468]
 * Move `body::AnyBody` to `awc`. Replaced with `EitherBody` and `BoxBody`. [#2468]
 * `impl Copy` for `ws::Codec`. [#1920]
+* `header::qitem` helper. Replaced with `header::QualityItem::max` [#2486]
+* `impl TryFrom<u16>` for `header::Quality` [#2486]
 
 [#2483]: https://github.com/actix/actix-web/pull/2483
 [#2468]: https://github.com/actix/actix-web/pull/2468
 [#1920]: https://github.com/actix/actix-web/pull/1920
+[#2486]: https://github.com/actix/actix-web/pull/2486
 
 
 ## 3.0.0-beta.14 - 2021-11-30

actix-http/Cargo.toml

@@ -112,3 +112,7 @@ harness = false
 [[bench]]
 name = "uninit-headers"
 harness = false
+
+[[bench]]
+name = "quality-value"
+harness = false

actix-http/benches/quality-value.rs

@@ -0,0 +1,90 @@
+use criterion::{criterion_group, criterion_main, BenchmarkId, Criterion};
+
+const CODES: &[u16] = &[0, 1000, 201, 800, 550];
+
+fn bench_quality_display_impls(c: &mut Criterion) {
+    let mut group = c.benchmark_group("quality value display impls");
+
+    for i in CODES.iter() {
+        group.bench_with_input(BenchmarkId::new("New (fast?)", i), i, |b, &i| {
+            b.iter(|| _new::Quality(i).to_string())
+        });
+
+        group.bench_with_input(BenchmarkId::new("Naive", i), i, |b, &i| {
+            b.iter(|| _naive::Quality(i).to_string())
+        });
+    }
+
+    group.finish();
+}
+
+criterion_group!(benches, bench_quality_display_impls);
+criterion_main!(benches);
+
+mod _new {
+    use std::fmt;
+
+    pub struct Quality(pub(crate) u16);
+
+    impl fmt::Display for Quality {
+        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+            match self.0 {
+                0 => f.write_str("0"),
+                1000 => f.write_str("1"),
+
+                // some number in the range 1–999
+                x => {
+                    f.write_str("0.")?;
+
+                    // this implementation avoids string allocation otherwise required
+                    // for `.trim_end_matches('0')`
+
+                    if x < 10 {
+                        f.write_str("00")?;
+                        // 0 is handled so it's not possible to have a trailing 0, we can just return
+                        itoa::fmt(f, x)
+                    } else if x < 100 {
+                        f.write_str("0")?;
+                        if x % 10 == 0 {
+                            // trailing 0, divide by 10 and write
+                            itoa::fmt(f, x / 10)
+                        } else {
+                            itoa::fmt(f, x)
+                        }
+                    } else {
+                        // x is in range 101–999
+
+                        if x % 100 == 0 {
+                            // two trailing 0s, divide by 100 and write
+                            itoa::fmt(f, x / 100)
+                        } else if x % 10 == 0 {
+                            // one trailing 0, divide by 10 and write
+                            itoa::fmt(f, x / 10)
+                        } else {
+                            itoa::fmt(f, x)
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+mod _naive {
+    use std::fmt;
+
+    pub struct Quality(pub(crate) u16);
+
+    impl fmt::Display for Quality {
+        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+            match self.0 {
+                0 => f.write_str("0"),
+                1000 => f.write_str("1"),
+
+                x => {
+                    write!(f, "{}", format!("{:03}", x).trim_end_matches('0'))
+                }
+            }
+        }
+    }
+}

actix-http/src/header/mod.rs

@@ -38,13 +38,14 @@ pub mod map;
 mod shared;
 mod utils;
 
-#[doc(hidden)]
-pub use self::shared::*;
-
 pub use self::as_name::AsHeaderName;
 pub use self::into_pair::IntoHeaderPair;
 pub use self::into_value::IntoHeaderValue;
 pub use self::map::HeaderMap;
+pub use self::shared::{
+    parse_extended_value, q, Charset, ContentEncoding, ExtendedValue, HttpDate,
+    LanguageTag, Quality, QualityItem,
+};
 pub use self::utils::{
     fmt_comma_delimited, from_comma_delimited, from_one_raw_str, http_percent_encode,
 };

actix-http/src/header/shared/extended.rs

@@ -1,4 +1,4 @@
-// Originally from hyper v0.11.27 src/header/parsing.rs
+//! Originally taken from `hyper::header::parsing`.
 
 use std::{fmt, str::FromStr};
 

actix-http/src/header/shared/mod.rs

@@ -4,11 +4,13 @@ mod charset;
 mod content_encoding;
 mod extended;
 mod http_date;
+mod quality;
 mod quality_item;
 
 pub use self::charset::Charset;
 pub use self::content_encoding::ContentEncoding;
 pub use self::extended::{parse_extended_value, ExtendedValue};
 pub use self::http_date::HttpDate;
-pub use self::quality_item::{q, qitem, Quality, QualityItem};
+pub use self::quality::{q, Quality};
+pub use self::quality_item::QualityItem;
 pub use language_tags::LanguageTag;

actix-http/src/header/shared/quality.rs

@@ -0,0 +1,208 @@
+use std::{
+    convert::{TryFrom, TryInto},
+    fmt,
+};
+
+use derive_more::{Display, Error};
+
+const MAX_QUALITY_INT: u16 = 1000;
+const MAX_QUALITY_FLOAT: f32 = 1.0;
+
+/// Represents a quality used in q-factor values.
+///
+/// The default value is equivalent to `q=1.0` (the [max](Self::MAX) value).
+///
+/// # Implementation notes
+/// The quality value is defined as a number between 0.0 and 1.0 with three decimal places.
+/// This means there are 1001 possible values. Since floating point numbers are not exact and the
+/// smallest floating point data type (`f32`) consumes four bytes, we use an `u16` value to store
+/// the quality internally.
+///
+/// [RFC 7231 §5.3.1] gives more information on quality values in HTTP header fields.
+///
+/// # Examples
+/// ```
+/// use actix_http::header::{Quality, q};
+/// assert_eq!(q(1.0), Quality::MAX);
+///
+/// assert_eq!(q(0.42).to_string(), "0.42");
+/// assert_eq!(q(1.0).to_string(), "1");
+/// assert_eq!(Quality::MIN.to_string(), "0");
+/// ```
+///
+/// [RFC 7231 §5.3.1]: https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.1
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub struct Quality(pub(super) u16);
+
+impl Quality {
+    /// The maximum quality value, equivalent to `q=1.0`.
+    pub const MAX: Quality = Quality(MAX_QUALITY_INT);
+
+    /// The minimum quality value, equivalent to `q=0.0`.
+    pub const MIN: Quality = Quality(0);
+
+    /// Converts a float in the range 0.0–1.0 to a `Quality`.
+    ///
+    /// Intentionally private. External uses should rely on the `TryFrom` impl.
+    ///
+    /// # Panics
+    /// Panics in debug mode when value is not in the range 0.0 <= n <= 1.0.
+    fn from_f32(value: f32) -> Self {
+        // Check that `value` is within range should be done before calling this method.
+        // Just in case, this debug_assert should catch if we were forgetful.
+        debug_assert!(
+            (0.0f32..=1.0f32).contains(&value),
+            "q value must be between 0.0 and 1.0"
+        );
+
+        Quality((value * MAX_QUALITY_INT as f32) as u16)
+    }
+}
+
+/// The default value is [`Quality::MAX`].
+impl Default for Quality {
+    fn default() -> Quality {
+        Quality::MAX
+    }
+}
+
+impl fmt::Display for Quality {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self.0 {
+            0 => f.write_str("0"),
+            MAX_QUALITY_INT => f.write_str("1"),
+
+            // some number in the range 1–999
+            x => {
+                f.write_str("0.")?;
+
+                // This implementation avoids string allocation for removing trailing zeroes.
+                // In benchmarks it is twice as fast as approach using something like
+                // `format!("{}").trim_end_matches('0')` for non-fast-path quality values.
+
+                if x < 10 {
+                    // x in is range 1–9
+
+                    f.write_str("00")?;
+
+                    // 0 is already handled so it's not possible to have a trailing 0 in this range
+                    // we can just write the integer
+                    itoa::fmt(f, x)
+                } else if x < 100 {
+                    // x in is range 10–99
+
+                    f.write_str("0")?;
+
+                    if x % 10 == 0 {
+                        // trailing 0, divide by 10 and write
+                        itoa::fmt(f, x / 10)
+                    } else {
+                        itoa::fmt(f, x)
+                    }
+                } else {
+                    // x is in range 100–999
+
+                    if x % 100 == 0 {
+                        // two trailing 0s, divide by 100 and write
+                        itoa::fmt(f, x / 100)
+                    } else if x % 10 == 0 {
+                        // one trailing 0, divide by 10 and write
+                        itoa::fmt(f, x / 10)
+                    } else {
+                        itoa::fmt(f, x)
+                    }
+                }
+            }
+        }
+    }
+}
+
+#[derive(Debug, Clone, Display, Error)]
+#[display(fmt = "quality out of bounds")]
+#[non_exhaustive]
+pub struct QualityOutOfBounds;
+
+impl TryFrom<f32> for Quality {
+    type Error = QualityOutOfBounds;
+
+    #[inline]
+    fn try_from(value: f32) -> Result<Self, Self::Error> {
+        if (0.0..=MAX_QUALITY_FLOAT).contains(&value) {
+            Ok(Quality::from_f32(value))
+        } else {
+            Err(QualityOutOfBounds)
+        }
+    }
+}
+
+/// Convenience function to create a [`Quality`] from an `f32` (0.0–1.0).
+///
+/// Not recommended for use with user input. Rely on the `TryFrom` impls where possible.
+///
+/// # Panics
+/// Panics if value is out of range.
+///
+/// # Examples
+/// ```
+/// # use actix_http::header::{q, Quality};
+/// let q1 = q(1.0);
+/// assert_eq!(q1, Quality::MAX);
+///
+/// let q2 = q(0.0);
+/// assert_eq!(q2, Quality::MIN);
+///
+/// let q3 = q(0.42);
+/// ```
+///
+/// An out-of-range `f32` quality will panic.
+/// ```should_panic
+/// # use actix_http::header::q;
+/// let _q2 = q(1.42);
+/// ```
+#[inline]
+pub fn q<T>(quality: T) -> Quality
+where
+    T: TryInto<Quality>,
+    T::Error: fmt::Debug,
+{
+    quality.try_into().expect("quality value was out of bounds")
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn q_helper() {
+        assert_eq!(q(0.5), Quality(500));
+    }
+
+    #[test]
+    fn display_output() {
+        assert_eq!(q(0.0).to_string(), "0");
+        assert_eq!(q(1.0).to_string(), "1");
+        assert_eq!(q(0.001).to_string(), "0.001");
+        assert_eq!(q(0.5).to_string(), "0.5");
+        assert_eq!(q(0.22).to_string(), "0.22");
+        assert_eq!(q(0.123).to_string(), "0.123");
+        assert_eq!(q(0.999).to_string(), "0.999");
+
+        for x in 0..=1000 {
+            // if trailing zeroes are handled correctly, we would not expect the serialized length
+            // to ever exceed "0." + 3 decimal places = 5 in length
+            assert!(q(x as f32 / 1000.0).to_string().len() <= 5);
+        }
+    }
+
+    #[test]
+    #[should_panic]
+    fn negative_quality() {
+        q(-1.0);
+    }
+
+    #[test]
+    #[should_panic]
+    fn quality_out_of_bounds() {
+        q(2.0);
+    }
+}

actix-http/src/header/shared/quality_item.rs

@@ -1,85 +1,36 @@
-use std::{
+use std::{cmp, convert::TryFrom as _, fmt, str};
-    cmp,
-    convert::{TryFrom, TryInto},
-    fmt, str,
-};
-
-use derive_more::{Display, Error};
 
 use crate::error::ParseError;
 
-const MAX_QUALITY: u16 = 1000;
+use super::Quality;
-const MAX_FLOAT_QUALITY: f32 = 1.0;
-
-/// Represents a quality used in quality values.
-///
-/// Can be created with the [`q`] function.
-///
-/// # Implementation notes
-///
-/// The quality value is defined as a number between 0 and 1 with three decimal
-/// places. This means there are 1001 possible values. Since floating point
-/// numbers are not exact and the smallest floating point data type (`f32`)
-/// consumes four bytes, hyper uses an `u16` value to store the
-/// quality internally. For performance reasons you may set quality directly to
-/// a value between 0 and 1000 e.g. `Quality(532)` matches the quality
-/// `q=0.532`.
-///
-/// [RFC 7231 §5.3.1](https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.1) gives more
-/// information on quality values in HTTP header fields.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
-pub struct Quality(u16);
-
-impl Quality {
-    /// # Panics
-    /// Panics in debug mode when value is not in the range 0.0 <= n <= 1.0.
-    fn from_f32(value: f32) -> Self {
-        // Check that `value` is within range should be done before calling this method.
-        // Just in case, this debug_assert should catch if we were forgetful.
-        debug_assert!(
-            (0.0f32..=1.0f32).contains(&value),
-            "q value must be between 0.0 and 1.0"
-        );
-
-        Quality((value * MAX_QUALITY as f32) as u16)
-    }
-}
-
-impl Default for Quality {
-    fn default() -> Quality {
-        Quality(MAX_QUALITY)
-    }
-}
-
-#[derive(Debug, Clone, Display, Error)]
-pub struct QualityOutOfBounds;
-
-impl TryFrom<u16> for Quality {
-    type Error = QualityOutOfBounds;
-
-    fn try_from(value: u16) -> Result<Self, Self::Error> {
-        if (0..=MAX_QUALITY).contains(&value) {
-            Ok(Quality(value))
-        } else {
-            Err(QualityOutOfBounds)
-        }
-    }
-}
-
-impl TryFrom<f32> for Quality {
-    type Error = QualityOutOfBounds;
-
-    fn try_from(value: f32) -> Result<Self, Self::Error> {
-        if (0.0..=MAX_FLOAT_QUALITY).contains(&value) {
-            Ok(Quality::from_f32(value))
-        } else {
-            Err(QualityOutOfBounds)
-        }
-    }
-}
 
 /// Represents an item with a quality value as defined
 /// in [RFC 7231 §5.3.1](https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.1).
+///
+/// # Parsing and Formatting
+/// This wrapper be used to parse header value items that have a q-factor annotation as well as
+/// serialize items with a their q-factor.
+///
+/// # Ordering
+/// Since this context of use for this type is header value items, ordering is defined for
+/// `QualityItem`s but _only_ considers the item's quality. Order of appearance should be used as
+/// the secondary sorting parameter; i.e., a stable sort over the quality values will produce a
+/// correctly sorted sequence.
+///
+/// # Examples
+/// ```
+/// # use actix_http::header::{QualityItem, q};
+/// let q_item: QualityItem<String> = "hello;q=0.3".parse().unwrap();
+/// assert_eq!(&q_item.item, "hello");
+/// assert_eq!(q_item.quality, q(0.3));
+///
+/// // note that format is normalized compared to parsed item
+/// assert_eq!(q_item.to_string(), "hello; q=0.3");
+///
+/// // item with q=0.3 is greater than item with q=0.1
+/// let q_item_fallback: QualityItem<String> = "abc;q=0.1".parse().unwrap();
+/// assert!(q_item > q_item_fallback);
+/// ```
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct QualityItem<T> {
     /// The wrapped contents of the field.
@@ -93,12 +44,22 @@ impl<T> QualityItem<T> {
     /// Constructs a new `QualityItem` from an item and a quality value.
     ///
     /// The item can be of any type. The quality should be a value in the range [0, 1].
-    pub fn new(item: T, quality: Quality) -> QualityItem<T> {
+    pub fn new(item: T, quality: Quality) -> Self {
         QualityItem { item, quality }
     }
+
+    /// Constructs a new `QualityItem` from an item, using the maximum q-value.
+    pub fn max(item: T) -> Self {
+        Self::new(item, Quality::MAX)
+    }
+
+    /// Constructs a new `QualityItem` from an item, using the minimum q-value.
+    pub fn min(item: T) -> Self {
+        Self::new(item, Quality::MIN)
+    }
 }
 
-impl<T: PartialEq> cmp::PartialOrd for QualityItem<T> {
+impl<T: PartialEq> PartialOrd for QualityItem<T> {
     fn partial_cmp(&self, other: &QualityItem<T>) -> Option<cmp::Ordering> {
         self.quality.partial_cmp(&other.quality)
     }
@@ -108,10 +69,12 @@ impl<T: fmt::Display> fmt::Display for QualityItem<T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Display::fmt(&self.item, f)?;
 
-        match self.quality.0 {
+        match self.quality {
-            MAX_QUALITY => Ok(()),
+            // q-factor value is implied for max value
-            0 => f.write_str("; q=0"),
+            Quality::MAX => Ok(()),
-            x => write!(f, "; q=0.{}", format!("{:03}", x).trim_end_matches('0')),
+
+            Quality::MIN => f.write_str("; q=0"),
+            q => write!(f, "; q={}", q),
         }
     }
 }
@@ -119,78 +82,58 @@ impl<T: fmt::Display> fmt::Display for QualityItem<T> {
 impl<T: str::FromStr> str::FromStr for QualityItem<T> {
     type Err = ParseError;
 
-    fn from_str(qitem_str: &str) -> Result<Self, Self::Err> {
+    fn from_str(q_item_str: &str) -> Result<Self, Self::Err> {
-        if !qitem_str.is_ascii() {
+        if !q_item_str.is_ascii() {
             return Err(ParseError::Header);
         }
 
-        // Set defaults used if parsing fails.
+        // set defaults used if quality-item parsing fails, i.e., item has no q attribute
-        let mut raw_item = qitem_str;
+        let mut raw_item = q_item_str;
-        let mut quality = 1f32;
+        let mut quality = Quality::MAX;
 
-        // TODO: MSRV(1.52): use rsplit_once
+        let parts = q_item_str
-        let parts: Vec<_> = qitem_str.rsplitn(2, ';').map(str::trim).collect();
+            .rsplit_once(';')
+            .map(|(item, q_attr)| (item.trim(), q_attr.trim()));
 
-        if parts.len() == 2 {
+        if let Some((val, q_attr)) = parts {
             // example for item with q-factor:
             //
-            // gzip; q=0.65
+            // gzip;q=0.65
-            //       ^^^^^^  parts[0]
+            // ^^^^         val
-            //       ^^      start
+            //      ^^^^^^  q_attr
+            //      ^^      q
             //        ^^^^  q_val
-            // ^^^^          parts[1]
 
-            if parts[0].len() < 2 {
+            if q_attr.len() < 2 {
                 // Can't possibly be an attribute since an attribute needs at least a name followed
                 // by an equals sign. And bare identifiers are forbidden.
                 return Err(ParseError::Header);
             }
 
-            let start = &parts[0][0..2];
+            let q = &q_attr[0..2];
 
-            if start == "q=" || start == "Q=" {
+            if q == "q=" || q == "Q=" {
-                let q_val = &parts[0][2..];
+                let q_val = &q_attr[2..];
                 if q_val.len() > 5 {
                     // longer than 5 indicates an over-precise q-factor
                     return Err(ParseError::Header);
                 }
 
                 let q_value = q_val.parse::<f32>().map_err(|_| ParseError::Header)?;
+                let q_value =
+                    Quality::try_from(q_value).map_err(|_| ParseError::Header)?;
 
-                if (0f32..=1f32).contains(&q_value) {
                 quality = q_value;
-                    raw_item = parts[1];
+                raw_item = val;
-                } else {
-                    return Err(ParseError::Header);
-                }
             }
         }
 
         let item = raw_item.parse::<T>().map_err(|_| ParseError::Header)?;
 
-        // we already checked above that the quality is within range
+        Ok(QualityItem::new(item, quality))
-        Ok(QualityItem::new(item, Quality::from_f32(quality)))
     }
 }
 
-/// Convenience function to wrap a value in a `QualityItem`
-/// Sets `q` to the default 1.0
-pub fn qitem<T>(item: T) -> QualityItem<T> {
-    QualityItem::new(item, Quality::default())
-}
-
-/// Convenience function to create a `Quality` from a float or integer.
-///
-/// Implemented for `u16` and `f32`. Panics if value is out of range.
-pub fn q<T>(val: T) -> Quality
-where
-    T: TryInto<Quality>,
-    T::Error: fmt::Debug,
-{
-    // TODO: on next breaking change, handle unwrap differently
-    val.try_into().unwrap()
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -245,7 +188,7 @@ mod tests {
     #[test]
     fn test_quality_item_fmt_q_1() {
         use Encoding::*;
-        let x = qitem(Chunked);
+        let x = QualityItem::max(Chunked);
         assert_eq!(format!("{}", x), "chunked");
     }
     #[test]
@@ -344,25 +287,8 @@ mod tests {
     fn test_quality_item_ordering() {
         let x: QualityItem<Encoding> = "gzip; q=0.5".parse().ok().unwrap();
         let y: QualityItem<Encoding> = "gzip; q=0.273".parse().ok().unwrap();
-        let comparision_result: bool = x.gt(&y);
+        let comparison_result: bool = x.gt(&y);
-        assert!(comparision_result)
+        assert!(comparison_result)
-    }
-
-    #[test]
-    fn test_quality() {
-        assert_eq!(q(0.5), Quality(500));
-    }
-
-    #[test]
-    #[should_panic]
-    fn test_quality_invalid() {
-        q(-1.0);
-    }
-
-    #[test]
-    #[should_panic]
-    fn test_quality_invalid2() {
-        q(2.0);
     }
 
     #[test]

actix-http/src/header/utils.rs

@@ -65,8 +65,9 @@ where
     Ok(())
 }
 
-/// Percent encode a sequence of bytes with a character set defined in
+/// Percent encode a sequence of bytes with a character set defined in [RFC 5987 §3.2].
-/// <https://datatracker.ietf.org/doc/html/rfc5987#section-3.2>
+///
+/// [RFC 5987 §3.2]: https://datatracker.ietf.org/doc/html/rfc5987#section-3.2
 #[inline]
 pub fn http_percent_encode(f: &mut fmt::Formatter<'_>, bytes: &[u8]) -> fmt::Result {
     let encoded = percent_encoding::percent_encode(bytes, HTTP_VALUE);

actix-multipart/src/server.rs

@@ -435,10 +435,10 @@ impl Field {
 
     /// Returns the field's Content-Disposition.
     ///
-    /// Per [RFC 7578 §4.2]: 'Each part MUST contain a Content-Disposition header field where the
+    /// Per [RFC 7578 §4.2]: "Each part MUST contain a Content-Disposition header field where the
-    /// disposition type is "form-data". The Content-Disposition header field MUST also contain an
+    /// disposition type is `form-data`. The Content-Disposition header field MUST also contain an
-    /// additional parameter of "name"; the value of the "name" parameter is the original field name
+    /// additional parameter of `name`; the value of the `name` parameter is the original field name
-    /// from the form.'
+    /// from the form."
     ///
     /// This crate validates that it exists before returning a `Field`. As such, it is safe to
     /// unwrap `.content_disposition().get_name()`. The [name](Self::name) method is provided as
@@ -451,7 +451,8 @@ impl Field {
 
     /// Returns the field's name.
     ///
-    /// See [content_disposition] regarding guarantees about
+    /// See [content_disposition](Self::content_disposition) regarding guarantees about existence of
+    /// the name field.
     pub fn name(&self) -> &str {
         self.content_disposition()
             .get_name()

src/http/header/accept.rs

@@ -2,7 +2,7 @@ use std::cmp::Ordering;
 
 use mime::Mime;
 
-use super::{qitem, QualityItem};
+use super::QualityItem;
 use crate::http::header;
 
 crate::http::header::common_header! {
@@ -34,46 +34,40 @@ crate::http::header::common_header! {
     /// # Examples
     /// ```
     /// use actix_web::HttpResponse;
-    /// use actix_web::http::header::{Accept, qitem};
+    /// use actix_web::http::header::{Accept, QualityItem};
     ///
     /// let mut builder = HttpResponse::Ok();
     /// builder.insert_header(
     ///     Accept(vec![
-    ///         qitem(mime::TEXT_HTML),
+    ///         QualityItem::max(mime::TEXT_HTML),
     ///     ])
     /// );
     /// ```
     ///
     /// ```
     /// use actix_web::HttpResponse;
-    /// use actix_web::http::header::{Accept, qitem};
+    /// use actix_web::http::header::{Accept, QualityItem};
     ///
     /// let mut builder = HttpResponse::Ok();
     /// builder.insert_header(
     ///     Accept(vec![
-    ///         qitem(mime::APPLICATION_JSON),
+    ///         QualityItem::max(mime::APPLICATION_JSON),
     ///     ])
     /// );
     /// ```
     ///
     /// ```
     /// use actix_web::HttpResponse;
-    /// use actix_web::http::header::{Accept, QualityItem, q, qitem};
+    /// use actix_web::http::header::{Accept, QualityItem, q};
     ///
     /// let mut builder = HttpResponse::Ok();
     /// builder.insert_header(
     ///     Accept(vec![
-    ///         qitem(mime::TEXT_HTML),
+    ///         QualityItem::max(mime::TEXT_HTML),
-    ///         qitem("application/xhtml+xml".parse().unwrap()),
+    ///         QualityItem::max("application/xhtml+xml".parse().unwrap()),
-    ///         QualityItem::new(
+    ///         QualityItem::new(mime::TEXT_XML, q(0.9)),
-    ///             mime::TEXT_XML,
+    ///         QualityItem::max("image/webp".parse().unwrap()),
-    ///             q(900)
+    ///         QualityItem::new(mime::STAR_STAR, q(0.8)),
-    ///         ),
-    ///         qitem("image/webp".parse().unwrap()),
-    ///         QualityItem::new(
-    ///             mime::STAR_STAR,
-    ///             q(800)
-    ///         ),
     ///     ])
     /// );
     /// ```
@@ -85,20 +79,20 @@ crate::http::header::common_header! {
             test1,
             vec![b"audio/*; q=0.2, audio/basic"],
             Some(Accept(vec![
-                QualityItem::new("audio/*".parse().unwrap(), q(200)),
+                QualityItem::new("audio/*".parse().unwrap(), q(0.2)),
-                qitem("audio/basic".parse().unwrap()),
+                QualityItem::max("audio/basic".parse().unwrap()),
                 ])));
 
         crate::http::header::common_header_test!(
             test2,
             vec![b"text/plain; q=0.5, text/html, text/x-dvi; q=0.8, text/x-c"],
             Some(Accept(vec![
-                QualityItem::new(mime::TEXT_PLAIN, q(500)),
+                QualityItem::new(mime::TEXT_PLAIN, q(0.5)),
-                qitem(mime::TEXT_HTML),
+                QualityItem::max(mime::TEXT_HTML),
                 QualityItem::new(
                     "text/x-dvi".parse().unwrap(),
-                    q(800)),
+                    q(0.8)),
-                qitem("text/x-c".parse().unwrap()),
+                QualityItem::max("text/x-c".parse().unwrap()),
                 ])));
 
         // Custom tests
@@ -106,14 +100,14 @@ crate::http::header::common_header! {
             test3,
             vec![b"text/plain; charset=utf-8"],
             Some(Accept(vec![
-                qitem(mime::TEXT_PLAIN_UTF_8),
+                QualityItem::max(mime::TEXT_PLAIN_UTF_8),
                 ])));
         crate::http::header::common_header_test!(
             test4,
             vec![b"text/plain; charset=utf-8; q=0.5"],
             Some(Accept(vec![
                 QualityItem::new(mime::TEXT_PLAIN_UTF_8,
-                    q(500)),
+                    q(0.5)),
             ])));
 
         #[test]
@@ -130,27 +124,27 @@ crate::http::header::common_header! {
 impl Accept {
     /// Construct `Accept: */*`.
     pub fn star() -> Accept {
-        Accept(vec![qitem(mime::STAR_STAR)])
+        Accept(vec![QualityItem::max(mime::STAR_STAR)])
     }
 
     /// Construct `Accept: application/json`.
     pub fn json() -> Accept {
-        Accept(vec![qitem(mime::APPLICATION_JSON)])
+        Accept(vec![QualityItem::max(mime::APPLICATION_JSON)])
     }
 
     /// Construct `Accept: text/*`.
     pub fn text() -> Accept {
-        Accept(vec![qitem(mime::TEXT_STAR)])
+        Accept(vec![QualityItem::max(mime::TEXT_STAR)])
     }
 
     /// Construct `Accept: image/*`.
     pub fn image() -> Accept {
-        Accept(vec![qitem(mime::IMAGE_STAR)])
+        Accept(vec![QualityItem::max(mime::IMAGE_STAR)])
     }
 
     /// Construct `Accept: text/html`.
     pub fn html() -> Accept {
-        Accept(vec![qitem(mime::TEXT_HTML)])
+        Accept(vec![QualityItem::max(mime::TEXT_HTML)])
     }
 
     /// Returns a sorted list of mime types from highest to lowest preference, accounting for
@@ -213,10 +207,10 @@ impl Accept {
     ///
     /// [q-factor weighting]: https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.2
     pub fn preference(&self) -> Mime {
-        use actix_http::header::q;
+        use actix_http::header::Quality;
 
         let mut max_item = None;
-        let mut max_pref = q(0);
+        let mut max_pref = Quality::MIN;
 
         // uses manual max lookup loop since we want the first occurrence in the case of same
         // preference but `Iterator::max_by_key` would give us the last occurrence
@@ -244,11 +238,11 @@ mod tests {
         let test = Accept(vec![]);
         assert!(test.ranked().is_empty());
 
-        let test = Accept(vec![qitem(mime::APPLICATION_JSON)]);
+        let test = Accept(vec![QualityItem::max(mime::APPLICATION_JSON)]);
         assert_eq!(test.ranked(), vec!(mime::APPLICATION_JSON));
 
         let test = Accept(vec![
-            qitem(mime::TEXT_HTML),
+            QualityItem::max(mime::TEXT_HTML),
             "application/xhtml+xml".parse().unwrap(),
             QualityItem::new("application/xml".parse().unwrap(), q(0.9)),
             QualityItem::new(mime::STAR_STAR, q(0.8)),
@@ -264,9 +258,9 @@ mod tests {
         );
 
         let test = Accept(vec![
-            qitem(mime::STAR_STAR),
+            QualityItem::max(mime::STAR_STAR),
-            qitem(mime::IMAGE_STAR),
+            QualityItem::max(mime::IMAGE_STAR),
-            qitem(mime::IMAGE_PNG),
+            QualityItem::max(mime::IMAGE_PNG),
         ]);
         assert_eq!(
             test.ranked(),
@@ -277,7 +271,7 @@ mod tests {
     #[test]
     fn preference_selection() {
         let test = Accept(vec![
-            qitem(mime::TEXT_HTML),
+            QualityItem::max(mime::TEXT_HTML),
             "application/xhtml+xml".parse().unwrap(),
             QualityItem::new("application/xml".parse().unwrap(), q(0.9)),
             QualityItem::new(mime::STAR_STAR, q(0.8)),
@@ -286,9 +280,9 @@ mod tests {
 
         let test = Accept(vec![
             QualityItem::new("video/*".parse().unwrap(), q(0.8)),
-            qitem(mime::IMAGE_PNG),
+            QualityItem::max(mime::IMAGE_PNG),
             QualityItem::new(mime::STAR_STAR, q(0.5)),
-            qitem(mime::IMAGE_SVG),
+            QualityItem::max(mime::IMAGE_SVG),
             QualityItem::new(mime::IMAGE_STAR, q(0.8)),
         ]);
         assert_eq!(test.preference(), mime::IMAGE_PNG);

src/http/header/accept_charset.rs

@@ -22,11 +22,11 @@ crate::http::header::common_header! {
     /// # Examples
     /// ```
     /// use actix_web::HttpResponse;
-    /// use actix_web::http::header::{AcceptCharset, Charset, qitem};
+    /// use actix_web::http::header::{AcceptCharset, Charset, QualityItem};
     ///
     /// let mut builder = HttpResponse::Ok();
     /// builder.insert_header(
-    ///     AcceptCharset(vec![qitem(Charset::Us_Ascii)])
+    ///     AcceptCharset(vec![QualityItem::max(Charset::Us_Ascii)])
     /// );
     /// ```
     ///
@@ -37,19 +37,19 @@ crate::http::header::common_header! {
     /// let mut builder = HttpResponse::Ok();
     /// builder.insert_header(
     ///     AcceptCharset(vec![
-    ///         QualityItem::new(Charset::Us_Ascii, q(900)),
+    ///         QualityItem::new(Charset::Us_Ascii, q(0.9)),
-    ///         QualityItem::new(Charset::Iso_8859_10, q(200)),
+    ///         QualityItem::new(Charset::Iso_8859_10, q(0.2)),
     ///     ])
     /// );
     /// ```
     ///
     /// ```
     /// use actix_web::HttpResponse;
-    /// use actix_web::http::header::{AcceptCharset, Charset, qitem};
+    /// use actix_web::http::header::{AcceptCharset, Charset, QualityItem};
     ///
     /// let mut builder = HttpResponse::Ok();
     /// builder.insert_header(
-    ///     AcceptCharset(vec![qitem(Charset::Ext("utf-8".to_owned()))])
+    ///     AcceptCharset(vec![QualityItem::max(Charset::Ext("utf-8".to_owned()))])
     /// );
     /// ```
     (AcceptCharset, ACCEPT_CHARSET) => (QualityItem<Charset>)+

src/http/header/accept_encoding.rs

@@ -29,36 +29,38 @@ common_header! {
     /// # Examples
     /// ```
     /// use actix_web::HttpResponse;
-    /// use actix_web::http::header::{AcceptEncoding, Encoding, qitem};
+    /// use actix_web::http::header::{AcceptEncoding, Encoding, QualityItem};
     ///
     /// let mut builder = HttpResponse::Ok();
     /// builder.insert_header(
-    ///     AcceptEncoding(vec![qitem(Encoding::Chunked)])
+    ///     AcceptEncoding(vec![QualityItem::max(Encoding::Chunked)])
     /// );
     /// ```
+    ///
     /// ```
     /// use actix_web::HttpResponse;
-    /// use actix_web::http::header::{AcceptEncoding, Encoding, qitem};
+    /// use actix_web::http::header::{AcceptEncoding, Encoding, QualityItem};
     ///
     /// let mut builder = HttpResponse::Ok();
     /// builder.insert_header(
     ///     AcceptEncoding(vec![
-    ///         qitem(Encoding::Chunked),
+    ///         QualityItem::max(Encoding::Chunked),
-    ///         qitem(Encoding::Gzip),
+    ///         QualityItem::max(Encoding::Gzip),
-    ///         qitem(Encoding::Deflate),
+    ///         QualityItem::max(Encoding::Deflate),
     ///     ])
     /// );
     /// ```
+    ///
     /// ```
     /// use actix_web::HttpResponse;
-    /// use actix_web::http::header::{AcceptEncoding, Encoding, QualityItem, q, qitem};
+    /// use actix_web::http::header::{AcceptEncoding, Encoding, QualityItem, q};
     ///
     /// let mut builder = HttpResponse::Ok();
     /// builder.insert_header(
     ///     AcceptEncoding(vec![
-    ///         qitem(Encoding::Chunked),
+    ///         QualityItem::max(Encoding::Chunked),
-    ///         QualityItem::new(Encoding::Gzip, q(600)),
+    ///         QualityItem::new(Encoding::Gzip, q(0.60)),
-    ///         QualityItem::new(Encoding::EncodingExt("*".to_owned()), q(0)),
+    ///         QualityItem::min(Encoding::EncodingExt("*".to_owned())),
     ///     ])
     /// );
     /// ```
@@ -77,3 +79,5 @@ common_header! {
         common_header_test!(test5, vec![b"gzip, identity; q=0.5, *;q=0"]);
     }
 }
+
+// TODO: shortcut for EncodingExt(*) = Any

src/http/header/accept_language.rs

@@ -1,6 +1,6 @@
 use language_tags::LanguageTag;
 
-use super::{common_header, Preference, QualityItem};
+use super::{common_header, Preference, Quality, QualityItem};
 use crate::http::header;
 
 common_header! {
@@ -32,26 +32,26 @@ common_header! {
     /// # Examples
     /// ```
     /// use actix_web::HttpResponse;
-    /// use actix_web::http::header::{AcceptLanguage, qitem};
+    /// use actix_web::http::header::{AcceptLanguage, QualityItem};
     ///
     /// let mut builder = HttpResponse::Ok();
     /// builder.insert_header(
     ///     AcceptLanguage(vec![
-    ///         qitem("en-US".parse().unwrap())
+    ///         QualityItem::max("en-US".parse().unwrap())
     ///     ])
     /// );
     /// ```
     ///
     /// ```
     /// use actix_web::HttpResponse;
-    /// use actix_web::http::header::{AcceptLanguage, QualityItem, q, qitem};
+    /// use actix_web::http::header::{AcceptLanguage, QualityItem, q};
     ///
     /// let mut builder = HttpResponse::Ok();
     /// builder.insert_header(
     ///     AcceptLanguage(vec![
-    ///         qitem("da".parse().unwrap()),
+    ///         QualityItem::max("da".parse().unwrap()),
-    ///         QualityItem::new("en-GB".parse().unwrap(), q(800)),
+    ///         QualityItem::new("en-GB".parse().unwrap(), q(0.8)),
-    ///         QualityItem::new("en".parse().unwrap(), q(700)),
+    ///         QualityItem::new("en".parse().unwrap(), q(0.7)),
     ///     ])
     /// );
     /// ```
@@ -72,9 +72,9 @@ common_header! {
             not_ordered_by_weight,
             vec![b"en-US, en; q=0.5, fr"],
             Some(AcceptLanguage(vec![
-                qitem("en-US".parse().unwrap()),
+                QualityItem::max("en-US".parse().unwrap()),
-                QualityItem::new("en".parse().unwrap(), q(500)),
+                QualityItem::new("en".parse().unwrap(), q(0.5)),
-                qitem("fr".parse().unwrap()),
+                QualityItem::max("fr".parse().unwrap()),
             ]))
         );
 
@@ -82,11 +82,11 @@ common_header! {
             has_wildcard,
             vec![b"fr-CH, fr; q=0.9, en; q=0.8, de; q=0.7, *; q=0.5"],
             Some(AcceptLanguage(vec![
-                qitem("fr-CH".parse().unwrap()),
+                QualityItem::max("fr-CH".parse().unwrap()),
-                QualityItem::new("fr".parse().unwrap(), q(900)),
+                QualityItem::new("fr".parse().unwrap(), q(0.9)),
-                QualityItem::new("en".parse().unwrap(), q(800)),
+                QualityItem::new("en".parse().unwrap(), q(0.8)),
-                QualityItem::new("de".parse().unwrap(), q(700)),
+                QualityItem::new("de".parse().unwrap(), q(0.7)),
-                QualityItem::new("*".parse().unwrap(), q(500)),
+                QualityItem::new("*".parse().unwrap(), q(0.5)),
             ]))
         );
     }
@@ -122,10 +122,8 @@ impl AcceptLanguage {
     ///
     /// [q-factor weighting]: https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.2
     pub fn preference(&self) -> Preference<LanguageTag> {
-        use actix_http::header::q;
-
         let mut max_item = None;
-        let mut max_pref = q(0);
+        let mut max_pref = Quality::MIN;
 
         // uses manual max lookup loop since we want the first occurrence in the case of same
         // preference but `Iterator::max_by_key` would give us the last occurrence
@@ -153,15 +151,15 @@ mod tests {
         let test = AcceptLanguage(vec![]);
         assert!(test.ranked().is_empty());
 
-        let test = AcceptLanguage(vec![qitem("fr-CH".parse().unwrap())]);
+        let test = AcceptLanguage(vec![QualityItem::max("fr-CH".parse().unwrap())]);
         assert_eq!(test.ranked(), vec!("fr-CH".parse().unwrap()));
 
         let test = AcceptLanguage(vec![
-            QualityItem::new("fr".parse().unwrap(), q(900)),
+            QualityItem::new("fr".parse().unwrap(), q(0.900)),
-            QualityItem::new("fr-CH".parse().unwrap(), q(1000)),
+            QualityItem::new("fr-CH".parse().unwrap(), q(1.0)),
-            QualityItem::new("en".parse().unwrap(), q(800)),
+            QualityItem::new("en".parse().unwrap(), q(0.800)),
-            QualityItem::new("*".parse().unwrap(), q(500)),
+            QualityItem::new("*".parse().unwrap(), q(0.500)),
-            QualityItem::new("de".parse().unwrap(), q(700)),
+            QualityItem::new("de".parse().unwrap(), q(0.700)),
         ]);
         assert_eq!(
             test.ranked(),
@@ -175,11 +173,11 @@ mod tests {
         );
 
         let test = AcceptLanguage(vec![
-            qitem("fr".parse().unwrap()),
+            QualityItem::max("fr".parse().unwrap()),
-            qitem("fr-CH".parse().unwrap()),
+            QualityItem::max("fr-CH".parse().unwrap()),
-            qitem("en".parse().unwrap()),
+            QualityItem::max("en".parse().unwrap()),
-            qitem("*".parse().unwrap()),
+            QualityItem::max("*".parse().unwrap()),
-            qitem("de".parse().unwrap()),
+            QualityItem::max("de".parse().unwrap()),
         ]);
         assert_eq!(
             test.ranked(),
@@ -196,11 +194,11 @@ mod tests {
     #[test]
     fn preference_selection() {
         let test = AcceptLanguage(vec![
-            QualityItem::new("fr".parse().unwrap(), q(900)),
+            QualityItem::new("fr".parse().unwrap(), q(0.900)),
-            QualityItem::new("fr-CH".parse().unwrap(), q(1000)),
+            QualityItem::new("fr-CH".parse().unwrap(), q(1.0)),
-            QualityItem::new("en".parse().unwrap(), q(800)),
+            QualityItem::new("en".parse().unwrap(), q(0.800)),
-            QualityItem::new("*".parse().unwrap(), q(500)),
+            QualityItem::new("*".parse().unwrap(), q(0.500)),
-            QualityItem::new("de".parse().unwrap(), q(700)),
+            QualityItem::new("de".parse().unwrap(), q(0.700)),
         ]);
         assert_eq!(
             test.preference(),
@@ -208,11 +206,11 @@ mod tests {
         );
 
         let test = AcceptLanguage(vec![
-            qitem("fr".parse().unwrap()),
+            QualityItem::max("fr".parse().unwrap()),
-            qitem("fr-CH".parse().unwrap()),
+            QualityItem::max("fr-CH".parse().unwrap()),
-            qitem("en".parse().unwrap()),
+            QualityItem::max("en".parse().unwrap()),
-            qitem("*".parse().unwrap()),
+            QualityItem::max("*".parse().unwrap()),
-            qitem("de".parse().unwrap()),
+            QualityItem::max("de".parse().unwrap()),
         ]);
         assert_eq!(
             test.preference(),

src/http/header/content_language.rs

@@ -23,25 +23,25 @@ common_header! {
     /// # Examples
     /// ```
     /// use actix_web::HttpResponse;
-    /// use actix_web::http::header::{ContentLanguage, LanguageTag, qitem};
+    /// use actix_web::http::header::{ContentLanguage, LanguageTag, QualityItem};
     ///
     /// let mut builder = HttpResponse::Ok();
     /// builder.insert_header(
     ///     ContentLanguage(vec![
-    ///         qitem(LanguageTag::parse("en").unwrap()),
+    ///         QualityItem::max(LanguageTag::parse("en").unwrap()),
     ///     ])
     /// );
     /// ```
     ///
     /// ```
     /// use actix_web::HttpResponse;
-    /// use actix_web::http::header::{ContentLanguage, LanguageTag, qitem};
+    /// use actix_web::http::header::{ContentLanguage, LanguageTag, QualityItem};
     ///
     /// let mut builder = HttpResponse::Ok();
     /// builder.insert_header(
     ///     ContentLanguage(vec![
-    ///         qitem(LanguageTag::parse("da").unwrap()),
+    ///         QualityItem::max(LanguageTag::parse("da").unwrap()),
-    ///         qitem(LanguageTag::parse("en-GB").unwrap()),
+    ///         QualityItem::max(LanguageTag::parse("en-GB").unwrap()),
     ///     ])
     /// );
     /// ```