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#[allow(unused, deprecated)]
use std::ascii::AsciiExt;
use std::cmp;
use std::default::Default;
use std::fmt;
use std::str;
#[cfg(test)]
use self::internal::IntoQuality;
/// 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`.
///
/// gives more information on quality values in HTTP header fields.
#[derive(Copy, Clone, Debug, Eq, Ord, PartialEq, PartialOrd)]
pub struct Quality(u16);
impl Default for Quality {
fn default() -> Quality {
Quality(1000)
}
}
/// Represents an item with a quality value as defined in
#[derive(Clone, PartialEq, Debug)]
pub struct QualityValue<T> {
/// The actual contents of the field.
value: T,
/// The quality (client or server preference) for the value.
quality: Quality,
}
impl<T> QualityValue<T> {
/// Creates a new `QualityValue` from an item and a quality.
pub fn new(value: T, quality: Quality) -> QualityValue<T> {
QualityValue {
value,
quality,
}
}
/*
/// Convenience function to set a `Quality` from a float or integer.
///
/// Implemented for `u16` and `f32`.
///
/// # Panic
///
/// Panics if value is out of range.
pub fn with_q<Q: IntoQuality>(mut self, q: Q) -> QualityValue<T> {
self.quality = q.into_quality();
self
}
*/
}
impl<T> From<T> for QualityValue<T> {
fn from(value: T) -> QualityValue<T> {
QualityValue {
value,
quality: Quality::default(),
}
}
}
impl<T: PartialEq> cmp::PartialOrd for QualityValue<T> {
fn partial_cmp(&self, other: &QualityValue<T>) -> Option<cmp::Ordering> {
self.quality.partial_cmp(&other.quality)
}
}
impl<T: fmt::Display> fmt::Display for QualityValue<T> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Display::fmt(&self.value, f)?;
match self.quality.0 {
1000 => Ok(()),
0 => f.write_str("; q=0"),
x => write!(f, "; q=0.{}", format!("{:03}", x).trim_right_matches('0'))
}
}
}
impl<T: str::FromStr> str::FromStr for QualityValue<T> {
type Err = ::Error;
fn from_str(s: &str) -> ::Result<QualityValue<T>> {
// Set defaults used if parsing fails.
let mut raw_item = s;
let mut quality = 1f32;
let parts: Vec<&str> = s.rsplitn(2, ';').map(|x| x.trim()).collect();
if parts.len() == 2 {
if parts[0].len() < 2 {
return Err(::Error::invalid());
}
if parts[0].starts_with("q=") || parts[0].starts_with("Q=") {
let q_part = &parts[0][2..parts[0].len()];
if q_part.len() > 5 {
return Err(::Error::invalid());
}
match q_part.parse::<f32>() {
Ok(q_value) => {
if 0f32 <= q_value && q_value <= 1f32 {
quality = q_value;
raw_item = parts[1];
} else {
return Err(::Error::invalid());
}
},
Err(_) => {
return Err(::Error::invalid())
},
}
}
}
match raw_item.parse::<T>() {
// we already checked above that the quality is within range
Ok(item) => Ok(QualityValue::new(item, from_f32(quality))),
Err(_) => {
Err(::Error::invalid())
},
}
}
}
#[inline]
fn from_f32(f: f32) -> Quality {
// this function is only used internally. A check that `f` is within range
// should be done before calling this method. Just in case, this
// debug_assert should catch if we were forgetful
debug_assert!(f >= 0f32 && f <= 1f32, "q value must be between 0.0 and 1.0");
Quality((f * 1000f32) as u16)
}
#[cfg(test)]
fn q<T: IntoQuality>(val: T) -> Quality {
val.into_quality()
}
mod internal {
use super::Quality;
// TryFrom is probably better, but it's not stable. For now, we want to
// keep the functionality of the `q` function, while allowing it to be
// generic over `f32` and `u16`.
//
// `q` would panic before, so keep that behavior. `TryFrom` can be
// introduced later for a non-panicking conversion.
pub trait IntoQuality: Sealed + Sized {
fn into_quality(self) -> Quality;
}
impl IntoQuality for f32 {
fn into_quality(self) -> Quality {
assert!(self >= 0f32 && self <= 1f32, "float must be between 0.0 and 1.0");
super::from_f32(self)
}
}
impl IntoQuality for u16 {
fn into_quality(self) -> Quality {
assert!(self <= 1000, "u16 must be between 0 and 1000");
Quality(self)
}
}
pub trait Sealed {}
impl Sealed for u16 {}
impl Sealed for f32 {}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_quality_item_fmt_q_1() {
let x = QualityValue::from("foo");
assert_eq!(format!("{}", x), "foo");
}
#[test]
fn test_quality_item_fmt_q_0001() {
let x = QualityValue::new("foo", Quality(1));
assert_eq!(format!("{}", x), "foo; q=0.001");
}
#[test]
fn test_quality_item_fmt_q_05() {
let x = QualityValue::new("foo", Quality(500));
assert_eq!(format!("{}", x), "foo; q=0.5");
}
#[test]
fn test_quality_item_fmt_q_0() {
let x = QualityValue::new("foo", Quality(0));
assert_eq!(x.to_string(), "foo; q=0");
}
#[test]
fn test_quality_item_from_str1() {
let x: QualityValue<String> = "chunked".parse().unwrap();
assert_eq!(x, QualityValue { value: "chunked".to_owned(), quality: Quality(1000), });
}
#[test]
fn test_quality_item_from_str2() {
let x: QualityValue<String> = "chunked; q=1".parse().unwrap();
assert_eq!(x, QualityValue { value: "chunked".to_owned(), quality: Quality(1000), });
}
#[test]
fn test_quality_item_from_str3() {
let x: QualityValue<String> = "gzip; q=0.5".parse().unwrap();
assert_eq!(x, QualityValue { value: "gzip".to_owned(), quality: Quality(500), });
}
#[test]
fn test_quality_item_from_str4() {
let x: QualityValue<String> = "gzip; q=0.273".parse().unwrap();
assert_eq!(x, QualityValue { value: "gzip".to_owned(), quality: Quality(273), });
}
#[test]
fn test_quality_item_from_str5() {
assert!("gzip; q=0.2739999".parse::<QualityValue<String>>().is_err());
}
#[test]
fn test_quality_item_from_str6() {
assert!("gzip; q=2".parse::<QualityValue<String>>().is_err());
}
#[test]
fn test_quality_item_ordering() {
let x: QualityValue<String> = "gzip; q=0.5".parse().unwrap();
let y: QualityValue<String> = "gzip; q=0.273".parse().unwrap();
assert!(x > y)
}
#[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]
fn test_fuzzing_bugs() {
assert!("99999;".parse::<QualityValue<String>>().is_err());
assert!("\x0d;;;=\u{d6aa}==".parse::<QualityValue<String>>().is_ok())
}
}