fix#123fix#154fix#265
This completely replaces the HTTP parser used to read and
parse incoming messages. The new version is faster than
the old one, and written in fewer lines. A summary of
changes:
* parse and async_parse renamed to read and async_read
* basic_parser is optimized for linear buffers,
use flat_streambuf for the best performance with these
functions:
- http::read
- http::read_some
- http::async_read
- http::async_read_some
* The overloads of read() and async_read() which take
just a header have been removed, since they would
throw away important parse metadata.
* The derived class callbacks for basic_parser have
been streamlined. All strings passed to callbacks
are presented in their entirety, instead of being
provided in pieces.
These changes allow use-cases that were previously
difficult or impossible, such as:
- Efficient relaying
- Late body type commitment
- Expect: 100-continue handling