Struct http::header::HeaderValue

pub struct HeaderValue { /* fields omitted */ }

Represents an HTTP header field value.

In practice, HTTP header field values are usually valid ASCII. However, the HTTP spec allows for a header value to contain opaque bytes as well. In this case, the header field value is not able to be represented as a string.

To handle this, the HeaderValue is useable as a type and can be compared with strings and implements Debug. A to_str fn is provided that returns an Err if the header value contains non visible ascii characters.

Methods

impl HeaderValue

fn from_static(src: &'static str) -> HeaderValue

Convert a static string to a HeaderValue.

This function will not perform any copying, however the string is checked to ensure that no invalid characters are present. Only visible ASCII characters (32-127) are permitted.

Panics

This function panics if the argument contains invalid header value characters.

Examples

let val = HeaderValue::from_static("hello");
assert_eq!(val, "hello");

fn from_str(src: &str) -> Result<HeaderValue, InvalidHeaderValue>

Attempt to convert a string to a HeaderValue.

If the argument contains invalid header value characters, an error is returned. Only visible ASCII characters (32-127) are permitted. Use from_bytes to create a HeaderValue that includes opaque octets (128-255).

This function is intended to be replaced in the future by a TryFrom implementation once the trait is stabilized in std.

Examples

let val = HeaderValue::from_str("hello").unwrap();
assert_eq!(val, "hello");

An invalid value

let val = HeaderValue::from_str("\n");
assert!(val.is_err());

fn from_bytes(src: &[u8]) -> Result<HeaderValue, InvalidHeaderValue>

Attempt to convert a byte slice to a HeaderValue.

If the argument contains invalid header value bytes, an error is returned. Only byte values between 32 and 255 (inclusive) are permitted, excluding byte 127 (DEL).

This function is intended to be replaced in the future by a TryFrom implementation once the trait is stabilized in std.

Examples

let val = HeaderValue::from_bytes(b"hello\xfa").unwrap();
assert_eq!(val, &b"hello\xfa"[..]);

An invalid value

let val = HeaderValue::from_bytes(b"\n");
assert!(val.is_err());

fn from_shared(src: Bytes) -> Result<HeaderValue, InvalidHeaderValueBytes>

Attempt to convert a Bytes buffer to a HeaderValue.

If the argument contains invalid header value bytes, an error is returned. Only byte values between 32 and 255 (inclusive) are permitted, excluding byte 127 (DEL).

This function is intended to be replaced in the future by a TryFrom implementation once the trait is stabilized in std.

unsafe fn from_shared_unchecked(src: Bytes) -> HeaderValue

Convert a Bytes directly into a HeaderValue without validating.

This function does NOT validate that illegal bytes are not contained within the buffer.

fn to_str(&self) -> Result<&str, ToStrError>

Yields a &str slice if the HeaderValue only contains visible ASCII chars.

This function will perform a scan of the header value, checking all the characters.

Examples

let val = HeaderValue::from_static("hello");
assert_eq!(val.to_str().unwrap(), "hello");

fn len(&self) -> usize

Returns the length of self.

This length is in bytes.

Examples

let val = HeaderValue::from_static("hello");
assert_eq!(val.len(), 5);

fn is_empty(&self) -> bool

Returns true if the HeaderValue has a length of zero bytes.

Examples

let val = HeaderValue::from_static("");
assert!(val.is_empty());

let val = HeaderValue::from_static("hello");
assert!(!val.is_empty());

fn as_bytes(&self) -> &[u8]

Converts a HeaderValue to a byte slice.

Examples

let val = HeaderValue::from_static("hello");
assert_eq!(val.as_bytes(), b"hello");

fn set_sensitive(&mut self, val: bool)

Mark that the header value represents sensitive information.

Examples

let mut val = HeaderValue::from_static("my secret");

val.set_sensitive(true);
assert!(val.is_sensitive());

val.set_sensitive(false);
assert!(!val.is_sensitive());

fn is_sensitive(&self) -> bool

Returns true if the value represents sensitive data.

Sensitive data could represent passwords or other data that should not be stored on disk or in memory. This setting can be used by components like caches to avoid storing the value. HPACK encoders must set the header field to never index when is_sensitive returns true.

Note that sensitivity is not factored into equality or ordering.

Examples

let mut val = HeaderValue::from_static("my secret");

val.set_sensitive(true);
assert!(val.is_sensitive());

val.set_sensitive(false);
assert!(!val.is_sensitive());

Trait Implementations

impl Clone for HeaderValue

fn clone(&self) -> HeaderValue

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Hash for HeaderValue

fn hash<__H: Hasher>(&self, __arg_0: &mut __H)

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given [Hasher].

impl AsRef<[u8]> for HeaderValue

fn as_ref(&self) -> &[u8]

Performs the conversion.

impl Debug for HeaderValue

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl FromStr for HeaderValue

type Err = InvalidHeaderValue

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<HeaderValue, Self::Err>

Parses a string s to return a value of this type.

impl<'a> HttpTryFrom<&'a str> for HeaderValue

type Error = InvalidHeaderValue

Associated error with the conversion this implementation represents.

fn try_from(t: &'a str) -> Result<Self, Self::Error>

impl<'a> HttpTryFrom<&'a [u8]> for HeaderValue

type Error = InvalidHeaderValue

Associated error with the conversion this implementation represents.

fn try_from(t: &'a [u8]) -> Result<Self, Self::Error>

impl HttpTryFrom<Bytes> for HeaderValue

type Error = InvalidHeaderValueBytes

Associated error with the conversion this implementation represents.

fn try_from(bytes: Bytes) -> Result<Self, Self::Error>

impl PartialEq for HeaderValue

fn eq(&self, other: &HeaderValue) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl Eq for HeaderValue

impl PartialOrd for HeaderValue

fn partial_cmp(&self, other: &HeaderValue) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Ord for HeaderValue

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

impl PartialEq<str> for HeaderValue

fn eq(&self, other: &str) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialEq<[u8]> for HeaderValue

fn eq(&self, other: &[u8]) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialOrd<str> for HeaderValue

fn partial_cmp(&self, other: &str) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl PartialOrd<[u8]> for HeaderValue

fn partial_cmp(&self, other: &[u8]) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl PartialEq<String> for HeaderValue

fn eq(&self, other: &String) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialOrd<String> for HeaderValue

fn partial_cmp(&self, other: &String) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a> PartialEq<HeaderValue> for &'a HeaderValue

fn eq(&self, other: &HeaderValue) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<'a> PartialOrd<HeaderValue> for &'a HeaderValue

fn partial_cmp(&self, other: &HeaderValue) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a, T: ?Sized> PartialEq<&'a T> for HeaderValue where
    HeaderValue: PartialEq<T>, 

fn eq(&self, other: &&'a T) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<'a, T: ?Sized> PartialOrd<&'a T> for HeaderValue where
    HeaderValue: PartialOrd<T>, 

fn partial_cmp(&self, other: &&'a T) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl HttpTryFrom<HeaderValue> for HeaderValue

type Error = Error

Associated error with the conversion this implementation represents.

fn try_from(t: Self) -> Result<Self, Self::Error>