The Raw type repesents the raw bytes of a header-value.
Having a special type allows a couple of benefits:
- The exact representation has become private, allowing "uglier"
internals. Specifically, since the common case is for a header to only
have 1 line of bytes, an enum is used to skip allocating a Vec for only
1 line. Additionally, a Cow<'static, [u8]> is used, so static bytes
don't require a copy. Finally, since we can use static bytes, when
parsing, we can compare the incoming bytes against a couple of the most
common header-values, and possibly remove another copy.
- As its own type, the `Headers.set_raw` method can be generic over
`Into<Raw>`, which allows for more ergnomic method calls.
BREAKING CHANGE: `Header::parse_header` now receives `&Raw`, instead of
a `&[Vec<u8>]`. `Raw` provides several methods to ease using it, but
may require some changes to existing code.
Header::parse_header() returns now a hyper Result instead of an option
this will enable more precise Error messages in the future, currently
most failures are reported as ::Error::Header.
BREAKING CHANGE: parse_header returns Result instead of Option, related
code did also change
`If-Match`, `If-None-Match` and `Vary` headers are either a "*" value meaning that the header
matches every possible item or a list of items, one of them must be matched to fulfil the condition.
BREAKING CHANGE: `If-Match`, `If-None-Match` and `Vary` item variant name changed to `Items`
It is no longer required, as we can use `<H as Header>::header_name()`.
BREAKING CHANGE: Implementations of Header will need to adjust the
header_name method. It no longer takes any arguments.
Currently headers are exported at many places. For example you can access
`Transfer-Encoding` header at `header`, `header::common` and
`header::common::transfer_encoding`. Per discussion on IRC with
@seanmonstar and @reem, all contents of headers will be exposed at `header`
directly. Parsing utilities will be exposed at `header::parsing`. Header
macros can now be used from other crates.
This breaks much code using headers. It should use everything it needs
directly from `header::`, encodings are exposed at `header::Encoding::`,
connection options are exposed at `header::ConnectionOption`.
- Some stray deriving -> derive changes
- use::{mod} -> use::{self}
- fmt.write -> fmt.write_str
This does not catch the last case of fmt.write_str in the
Show impl of a Header Item. This will need to be changed
separately.
