This works similarly to bind_handler, and can help with reducing
template instantiations and compiler memory usage (since it does
not need to support placeholders).
A specialization for the most common case `void(error_code, size_t)`
is provided to minimize instantiation cost.
fix#1270
basic_fields::value_type uses base hooks instead of member hooks,
otherwise MSVC can sometimes produce undefined behavior when
attempting to recover the base class from a data member in
certain build configurations.
fix#1133, fix#1241
When the macro BOOST_BEAST_USE_STD_STRING_VIEW is defined,
Beast will use std::string_view instead of boost::string_view.
The name boost::beast::string_view is a type alias for the
chosen view type.
fix#1237
HTTP client examples now verify the server's certificate
and generate an error if the certificate is invalid or
expired:
* Set certificate verify mode
* Remove duplicate root certificate
fix#1245, fix#1249
The value used to fill the incomplete code point buffer is
changed to a character which no longer causes
utf8_checker::valid() to incorrectly return false.
This resolves a medium vulnerability described in the
Beast Hybrid Assessment Report by Bishop Fox, where masks generated
for use with outgoing WebSocket client frames use an insufficient
source of entropy and a non-cryptographically secure pseudo-random
number generator.
By default, all newly constructed WebSocket streams will use a
uniquely seeded secure PRNG (ChaCha20 in counter mode). As this may
result in increased CPU resource consumption, the function
websocket::stream::secure_prng() may be used to select a faster but
less secure PRNG, for the case where the caller knows that the secure
generator is not necessary.
On some systems, std::random_device may produce insufficient entropy
to securely seed the PRNG. As this condition cannot be detected by
Beast, callers may use the function websocket::seed_prng() called
once at startup to provide at least 256 bits of entropy which will
be used to uniquely seed all subsequent PRNGs.
The ssl_stream wrapper provides C++11 move semantics for ssl::stream,
as well as incorporating the flat_stream workaround for a performance
problem with ssl::stream writes and buffer sequences having length
greater than one.
fix#1108
The `flat_stream` is a stream wrapper designed to overcome a
performance limitation of the `boost::asio::ssl::stream`
implementation. Specifically, when writing buffer sequences having
length greater than one, the `ssl::stream` implementation does
not use scatter-gather I/O and instead performs a kernel transition
for every buffer in the sequence.
The wrapper addresses this problem by allocating memory and
presenting the buffer sequence into a single buffer, using
some logic to determine when this allocation is advantageous
versus simply passing the buffers through as-is.
See Also:
https://github.com/boostorg/asio/issues/100https://stackoverflow.com/questions/50026167/performance-drop-on-port-from-beast-1-0-0-b66-to-boost-1-67-0-beast
fix#1076
As per Asio and Networking TS requirements, composed operations must
maintain an object of type executor_work_guard for the executor associated
with the I/O object, for the lifetime of the asynchronous operation.
This is in addition to the requirement for maintaining an object of type
executor_work_guard for the executor associated with the handler.
fix#941, fix#1016
`get_lowest_layer` is now a type alias for the
lowest layer instead of a struct with a nested type.
Actions required:
* Replace instances of `typename get_lowest_layer<T>::type`
with `get_lowest_layer<T>`.
Vinnie Falco