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.
* The handler_ptr constructor now provides the
strong exception guarantee.
* The signature for managed objects constructed by
`handler_ptr` receives a const reference to the handler.
Actions required:
* Change the constructor signature for state objects
used with handler_ptr to receive a const reference to
the handler.
fix#899
The timer logic for the advanced-server and advanced-server-flex
examples is refactored to use idle pings when the connection has
not seen activity for some period of time. This demonstrates the
use of the stream's control_callback interface.
fix#769
The following classes are removed:
* handler_type
* async_result
* async_completion
* is_dynamic_buffer
* is_const_buffer_sequence
* is_mutable_buffer_sequence
* handler_alloc
Actions Required:
* Use BOOST_ASIO_HANDLER_TYPE instead of handler_type
* Use BOOST_ASIO_INITFN_RESULT_TYPE instead of async_result
* Use boost::asio::async_completion
* Use boost::asio::is_dynamic_buffer
* Use boost::asio::is_const_buffer_sequence
* Use boost::asio::is_mutable_buffer_sequence
* boost::asio::associated_allocator_t replaces handler_alloc
fix#767
The write family of HTTP stream algorithms no longer returns
error::end_of_stream when the message indicates that the connection
should be closed.
Actions Required:
* Add code to servers to close the connection after successfully
writing a message where `message::keep_alive()` would return `false`.
fix#773
* buffer_prefix is renamed to buffers_prefix
* buffer_prefix_view is renamed to buffers_prefix_view
Actions Required:
* Use buffers_prefix instead of buffer_prefix
* Use buffers_prefix_view instead of buffer_prefix_view
fix#778
* The version data member is replaced with accessor
member functions.
Actions Required:
* Call member function message::version instead of accessing
the version member at call sites.
fix#778
* The body data member is replaced with accessor
member functions.
Actions Required:
* Call member function message::body instead of accessing
the data member at call sites.
* HTTP read and write operations now return the
number of bytes transferred to or from the stream.
Actions Required:
* Modify HTTP read and/or write completion handlers to receive
the extra std::size_t bytes_transferred parameter.
* Stream write operations now return the number of bytes
transferred from the caller's input buffers.
Actions Required:
* Modify websocket write completion handlers to receive
the extra std::size_t bytes_transferred parameter.
fix#575, fix#604, fix#608, fix#634, fix#712
All examples are rewritten:
* Using Best Practices
* Mostly self-contained
* New examples to complete the feature matrix
* The server-framework example is removed
* teardown_tag is replaced with teardown_role, a client/server
flag used to determine whether the shutdown is performed
before or after reading the EOF. This is in accordance with
RFC6455 7.1.1:
https://tools.ietf.org/html/rfc6455#section-7.1.1
Actions Required:
* Modify signatures of teardown and async_teardown to use
teardown_role instead of teardown_tag
* Change calls to teardown and async_teardown to pass the
correct role: client or server depending on context.
fix#642
* Calls to stream::close and stream::async_close will
automatically perform the required read operations
Actions Required:
* Remove calling code which drains the connection after
calling stream::close or stream::async_close
The websocket stream is optimized to contain a small
circular static buffer, reducing the number of I/O calls when
reading data. The size of the buffer is tuned for maximum
performance with TCP/IP and no long needs configuration:
* read_some replaces read_frame
* write_some replaces write_Frame
* async_read_some replaces async_read_frame
* async_write_some replaces async_write_frame
* websocket::stream::read_buffer_size is removed
Actions Required:
* Remove calls websocket::stream::read_buffer_size
* Use read_some and write_some instead of read_frame and write_frame
* parser now has a callback feature for intercepting chunk headers
and chunk bodies
* The names for basic_parser derived class callbacks have been
refactored
* basic_parser offers an additional callback for distinguishing
chunk body data.
Actions Required:
* Adjust signatures for required members of user-defined
subclasses of basic_parser
* Use the new basic_parser chunk callbacks for accessing
chunk extensions and chunk bodies.
New buffer sequence classes are provided to allow full
control over the serialization of chunk-encoded message
payloads:
* chunk_header
A ConstBufferSequence representing the chunk header.
It includes a hexadecimal-encoded size, an optional
set of chunk extensions, and the trailing CRLF
required to denote the end of the chunk header.
This allows the caller to manually serialize the chunk
body in one or more calls to a stream output function.
The caller must also output an object of type `chunk_crlf`
to the stream to indicate the end of the chunk body.
* chunk_crlf
A small ConstBufferSequence that simply represents
the two character sequence "\r\n" (CRLF). This is needed
for the case where the caller wants to output a chunk
body as a series of buffers (i.e. "chunking a chunk").
* chunk_body
A ConstBufferSequence representing a complete chunk.
This includes the size, an optional set of chunk extensions,
a caller provided buffer containing the body, and the
required CRLF that follows.
* chunk_final
A ConstBufferSequence representing a final chunk. It
includes an optional set of caller-provided field trailers
* chunk_extensions
A container for building a set of chunk extensions to use
during serialization. The use of the container is optional,
callers may provide their own buffer containing a correctly
formatted set of chunk extensions, or they may use their
own convenience container which meets the requirements.
The basic_fields container is modified to allow construction
outside the context of a message. The container can be used
to provide trailers to `chunk_final`.
Actions Required:
* Remove references to ChunkDecorators. Use the new chunk-encoding
buffer sequences to manually produce a chunked payload body in
the case where control over the chunk-extensions and/or trailers
is required.
These types now perform error-based initialization in
a separate init() functions instead of in the constructor.
Actions Required:
* Modify instances of user-defined BodyReader and BodyWriter
types to perfrom two-phase initialization, as per the
updated documented type requirements.
fix#581
* request and response headers now have convenience
constructors so important fields like method, target,
result, and version may be set upon construction.
Actions Required:
* Evaluate each message constructor call site and
adjust the constructor argument list as needed.
fix#578
- Receive request in a single read
- Use fields_alloc for response
- Fix command line usage information
- Add command line option to spin the io_service
`put` returns the number of bytes actually transferred
from the input buffers.
Actions Required:
* Return the number of bytes actually transferred from the
input buffers in user defined `Body::writer::put` functions.
The is_deferred nested type is removed from the BodyReader
requirements.
Performance for sending messages with `file_body` was cut
almost in half with is_deferred as `std::true_type` since
it caused double the number of socket writes. If the
deferred behavior is absolutely necessary, callers can get
the same effect by manually sending the headers first.
Actions Required:
* Callers who need the behavior of is_deferred as `std::true_type`
should manually construct a serializer and serialize the header
first, followed by the body.
Actions Required:
* Change calls to msg.prepare to msg.prepare_payload. For messages
with a user-defined Fields, provide the function prepare_payload_impl
in the fields type according to the Fields requirements.
Every interface or implementation which operates on a templated
type Fields is evaluated to determine if basic_fields<Allocator>
is more appropriate, and changed if so.
* `parser` is now templated on Allocator
* `parser` only produces messages using `basic_fields<Allocator>`
as the Fields type.
* message-oriented read and async_read only work on messages
using basic_fields as the Fields type.
Actions Required:
* Callers using `parser` with Fields types other than basic_fields
will need to create their own subclass of basic_parser to work
with their custom fields type.
fix#297, fix#488
* Errors are checked and reported
* More comments explaining what is going on
* The connection is gracefully closed
WebSocket:
* Messages are drained before closing
fix#497
This changes the function signature to accept the `value_type`
instead of the entire message.
Actions Required:
* For any user-defined models of Body, change the function signature
to accept `value_type const&` and modify the function definition
accordingly.
