fix#185, fix#489
* SSE4.2 is detected
* basic_parser uses SSE4.2 if available
* basic_parser tries to parse on the initial buffer and if
it does not find the end of header it shifts to a new
strategy of waiting for the end of header to defeat
slow loris attacks. This coincidentally is also faster
than the previous algorithm.
* detail::read_size_helper is removed
* public function read_size helps determine the optimum
size for calls to a DynamicBuffer's prepare function.
* special case for Asio types which don't conform to
the concept but have their own helper function.
read_size_helper can return zero if the buffer reaches
its maximum size, causing infinite loops in HTTP. The
function maybe_read_size_helper is provided to throw
an exception instead of returning a value for this case.
fix#440
WARNING
multi_buffer constructor now takes a maximum size instead of the
"allocation size". This is a breaking change. The allocation size
feature is removed. To update calling code, remove the allocation
size parameter from call sites.
* multi_buffer now uses a geometric growth algorithm for better performance.
The static buffer is updated:
* reset() is no longer a member. Use b.consume(b.size()) instead.
* Simplified implementaton, uses asio instead of custom types
* Better stream performance: consuming the input makes room
available in the output. This class is now suitable for
HTTP reads.
These changes permit the static_buffer wrapper to adapt a user
memory buffer if desired, including a stack based array.
The static_buffer_n class may also be used for this purpose,
it comes with its own storage.
Vinnie Falco
octopus-prime