boost/beast/http/read.hpp
// // Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com) // // Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) // // Official repository: https://github.com/boostorg/beast // #ifndef BOOST_BEAST_HTTP_READ_HPP #define BOOST_BEAST_HTTP_READ_HPP #include <boost/beast/core/detail/config.hpp> #include <boost/beast/core/error.hpp> #include <boost/beast/core/stream_traits.hpp> #include <boost/beast/http/basic_parser.hpp> #include <boost/beast/http/message.hpp> #include <boost/asio/async_result.hpp> namespace boost { namespace beast { namespace http { //------------------------------------------------------------------------------ /** Read part of a message from a stream using a parser. This function is used to read part of a message from a stream into an instance of @ref basic_parser. The call will block until one of the following conditions is true: @li A call to @ref basic_parser::put with a non-empty buffer sequence is successful. @li An error occurs. This operation is implemented in terms of one or more calls to the stream's `read_some` function. The implementation may read additional bytes from the stream that lie past the end of the message being read. These additional bytes are stored in the dynamic buffer, which must be preserved for subsequent reads. If the end of file error is received while reading from the stream, then the error returned from this function will be: @li @ref error::end_of_stream if no bytes were parsed, or @li @ref error::partial_message if any bytes were parsed but the message was incomplete, otherwise: @li A successful result. The next attempt to read will return @ref error::end_of_stream @param stream The stream from which the data is to be read. The type must meet the <em>SyncReadStream</em> requirements. @param buffer Storage for additional bytes read by the implementation from the stream. This is both an input and an output parameter; on entry, the parser will be presented with any remaining data in the dynamic buffer's readable bytes sequence first. The type must meet the <em>DynamicBuffer</em> requirements. @param parser The parser to use. @return The number of bytes transferred from the stream. @throws system_error Thrown on failure. @note The function returns the total number of bytes transferred from the stream. This may be zero for the case where there is sufficient pre-existing message data in the dynamic buffer. */ template< class SyncReadStream, class DynamicBuffer, bool isRequest> std::size_t read_some( SyncReadStream& stream, DynamicBuffer& buffer, basic_parser<isRequest>& parser); /** Read part of a message from a stream using a parser. This function is used to read part of a message from a stream into an instance of @ref basic_parser. The call will block until one of the following conditions is true: @li A call to @ref basic_parser::put with a non-empty buffer sequence is successful. @li An error occurs. This operation is implemented in terms of one or more calls to the stream's `read_some` function. The implementation may read additional bytes from the stream that lie past the end of the message being read. These additional bytes are stored in the dynamic buffer, which must be preserved for subsequent reads. If the end of file error is received while reading from the stream, then the error returned from this function will be: @li @ref error::end_of_stream if no bytes were parsed, or @li @ref error::partial_message if any bytes were parsed but the message was incomplete, otherwise: @li A successful result. The next attempt to read will return @ref error::end_of_stream @param stream The stream from which the data is to be read. The type must support the <em>SyncReadStream</em> requirements. @param buffer Storage for additional bytes read by the implementation from the stream. This is both an input and an output parameter; on entry, the parser will be presented with any remaining data in the dynamic buffer's readable bytes sequence first. The type must meet the <em>DynamicBuffer</em> requirements. @param parser The parser to use. @param ec Set to the error, if any occurred. @return The number of bytes transferred from the stream. @note The function returns the total number of bytes transferred from the stream. This may be zero for the case where there is sufficient pre-existing message data in the dynamic buffer. */ template< class SyncReadStream, class DynamicBuffer, bool isRequest> std::size_t read_some( SyncReadStream& stream, DynamicBuffer& buffer, basic_parser<isRequest>& parser, error_code& ec); /** Read part of a message asynchronously from a stream using a parser. This function is used to asynchronously read part of a message from a stream into an instance of @ref basic_parser. The function call always returns immediately. The asynchronous operation will continue until one of the following conditions is true: @li A call to @ref basic_parser::put with a non-empty buffer sequence is successful. @li An error occurs. This operation is implemented in terms of zero or more calls to the next layer's `async_read_some` function, and is known as a <em>composed operation</em>. The program must ensure that the stream performs no other reads until this operation completes. The implementation may read additional bytes from the stream that lie past the end of the message being read. These additional bytes are stored in the dynamic buffer, which must be preserved for subsequent reads. If the end of file error is received while reading from the stream, then the error returned from this function will be: @li @ref error::end_of_stream if no bytes were parsed, or @li @ref error::partial_message if any bytes were parsed but the message was incomplete, otherwise: @li A successful result. The next attempt to read will return @ref error::end_of_stream @param stream The stream from which the data is to be read. The type must meet the <em>AsyncReadStream</em> requirements. @param buffer Storage for additional bytes read by the implementation from the stream. This is both an input and an output parameter; on entry, the parser will be presented with any remaining data in the dynamic buffer's readable bytes sequence first. The type must meet the <em>DynamicBuffer</em> requirements. The object must remain valid at least until the handler is called; ownership is not transferred. @param parser The parser to use. The object must remain valid at least until the handler is called; ownership is not transferred. @param handler The completion handler to invoke when the operation completes. The implementation takes ownership of the handler by performing a decay-copy. The equivalent function signature of the handler must be: @code void handler( error_code const& error, // result of operation std::size_t bytes_transferred // the total number of bytes transferred from the stream ); @endcode Regardless of whether the asynchronous operation completes immediately or not, the handler will not be invoked from within this function. Invocation of the handler will be performed in a manner equivalent to using `net::post`. @note The completion handler will receive as a parameter the total number of bytes transferred from the stream. This may be zero for the case where there is sufficient pre-existing message data in the dynamic buffer. @par Per-Operation Cancellation This asynchronous operation supports cancellation for the following net::cancellation_type values: @li @c net::cancellation_type::terminal if the `stream` also supports terminal cancellation. `terminal` cancellation leaves the stream in an undefined state, so that only closing it is guaranteed to succeed. */ template< class AsyncReadStream, class DynamicBuffer, bool isRequest, BOOST_BEAST_ASYNC_TPARAM2 ReadHandler = net::default_completion_token_t< executor_type<AsyncReadStream>>> BOOST_BEAST_ASYNC_RESULT2(ReadHandler) async_read_some( AsyncReadStream& stream, DynamicBuffer& buffer, basic_parser<isRequest>& parser, ReadHandler&& handler = net::default_completion_token_t< executor_type<AsyncReadStream>>{}); //------------------------------------------------------------------------------ /** Read a complete message header from a stream using a parser. This function is used to read a complete message header from a stream into an instance of @ref basic_parser. The call will block until one of the following conditions is true: @li @ref basic_parser::is_header_done returns `true` @li An error occurs. This operation is implemented in terms of one or more calls to the stream's `read_some` function. The implementation may read additional bytes from the stream that lie past the end of the message being read. These additional bytes are stored in the dynamic buffer, which must be preserved for subsequent reads. If the end of file error is received while reading from the stream, then the error returned from this function will be: @li @ref error::end_of_stream if no bytes were parsed, or @li @ref error::partial_message if any bytes were parsed but the message was incomplete, otherwise: @li A successful result. The next attempt to read will return @ref error::end_of_stream @param stream The stream from which the data is to be read. The type must meet the <em>SyncReadStream</em> requirements. @param buffer Storage for additional bytes read by the implementation from the stream. This is both an input and an output parameter; on entry, the parser will be presented with any remaining data in the dynamic buffer's readable bytes sequence first. The type must meet the <em>DynamicBuffer</em> requirements. @param parser The parser to use. @return The number of bytes transferred from the stream. @throws system_error Thrown on failure. @note The function returns the total number of bytes transferred from the stream. This may be zero for the case where there is sufficient pre-existing message data in the dynamic buffer. The implementation will call @ref basic_parser::eager with the value `false` on the parser passed in. */ template< class SyncReadStream, class DynamicBuffer, bool isRequest> std::size_t read_header( SyncReadStream& stream, DynamicBuffer& buffer, basic_parser<isRequest>& parser); /** Read a complete message header from a stream using a parser. This function is used to read a complete message header from a stream into an instance of @ref basic_parser. The call will block until one of the following conditions is true: @li @ref basic_parser::is_header_done returns `true` @li An error occurs. This operation is implemented in terms of one or more calls to the stream's `read_some` function. The implementation may read additional bytes from the stream that lie past the end of the message being read. These additional bytes are stored in the dynamic buffer, which must be preserved for subsequent reads. If the end of file error is received while reading from the stream, then the error returned from this function will be: @li @ref error::end_of_stream if no bytes were parsed, or @li @ref error::partial_message if any bytes were parsed but the message was incomplete, otherwise: @li A successful result. The next attempt to read will return @ref error::end_of_stream @param stream The stream from which the data is to be read. The type must meet the <em>SyncReadStream</em> requirements. @param buffer Storage for additional bytes read by the implementation from the stream. This is both an input and an output parameter; on entry, the parser will be presented with any remaining data in the dynamic buffer's readable bytes sequence first. The type must meet the <em>DynamicBuffer</em> requirements. @param parser The parser to use. @param ec Set to the error, if any occurred. @return The number of bytes transferred from the stream. @note The function returns the total number of bytes transferred from the stream. This may be zero for the case where there is sufficient pre-existing message data in the dynamic buffer. The implementation will call @ref basic_parser::eager with the value `false` on the parser passed in. */ template< class SyncReadStream, class DynamicBuffer, bool isRequest> std::size_t read_header( SyncReadStream& stream, DynamicBuffer& buffer, basic_parser<isRequest>& parser, error_code& ec); /** Read a complete message header asynchronously from a stream using a parser. This function is used to asynchronously read a complete message header from a stream into an instance of @ref basic_parser. The function call always returns immediately. The asynchronous operation will continue until one of the following conditions is true: @li @ref basic_parser::is_header_done returns `true` @li An error occurs. This operation is implemented in terms of zero or more calls to the next layer's `async_read_some` function, and is known as a <em>composed operation</em>. The program must ensure that the stream performs no other reads until this operation completes. The implementation may read additional bytes from the stream that lie past the end of the message being read. These additional bytes are stored in the dynamic buffer, which must be preserved for subsequent reads. If the end of file error is received while reading from the stream, then the error returned from this function will be: @li @ref error::end_of_stream if no bytes were parsed, or @li @ref error::partial_message if any bytes were parsed but the message was incomplete, otherwise: @li A successful result. The next attempt to read will return @ref error::end_of_stream @param stream The stream from which the data is to be read. The type must meet the <em>AsyncReadStream</em> requirements. @param buffer Storage for additional bytes read by the implementation from the stream. This is both an input and an output parameter; on entry, the parser will be presented with any remaining data in the dynamic buffer's readable bytes sequence first. The type must meet the <em>DynamicBuffer</em> requirements. The object must remain valid at least until the handler is called; ownership is not transferred. @param parser The parser to use. The object must remain valid at least until the handler is called; ownership is not transferred. @param handler The completion handler to invoke when the operation completes. The implementation takes ownership of the handler by performing a decay-copy. The equivalent function signature of the handler must be: @code void handler( error_code const& error, // result of operation std::size_t bytes_transferred // the total number of bytes transferred from the stream ); @endcode Regardless of whether the asynchronous operation completes immediately or not, the handler will not be invoked from within this function. Invocation of the handler will be performed in a manner equivalent to using `net::post`. @note The completion handler will receive as a parameter the total number of bytes transferred from the stream. This may be zero for the case where there is sufficient pre-existing message data in the dynamic buffer. The implementation will call @ref basic_parser::eager with the value `false` on the parser passed in. @par Per-Operation Cancellation This asynchronous operation supports cancellation for the following net::cancellation_type values: @li @c net::cancellation_type::terminal if the `stream` also supports terminal cancellation. `terminal` cancellation leaves the stream in an undefined state, so that only closing it is guaranteed to succeed. */ template< class AsyncReadStream, class DynamicBuffer, bool isRequest, BOOST_BEAST_ASYNC_TPARAM2 ReadHandler = net::default_completion_token_t< executor_type<AsyncReadStream>>> BOOST_BEAST_ASYNC_RESULT2(ReadHandler) async_read_header( AsyncReadStream& stream, DynamicBuffer& buffer, basic_parser<isRequest>& parser, ReadHandler&& handler = net::default_completion_token_t< executor_type<AsyncReadStream>>{}); //------------------------------------------------------------------------------ /** Read a complete message from a stream using a parser. This function is used to read a complete message from a stream into an instance of @ref basic_parser. The call will block until one of the following conditions is true: @li @ref basic_parser::is_done returns `true` @li An error occurs. This operation is implemented in terms of one or more calls to the stream's `read_some` function. The implementation may read additional bytes from the stream that lie past the end of the message being read. These additional bytes are stored in the dynamic buffer, which must be preserved for subsequent reads. If the end of file error is received while reading from the stream, then the error returned from this function will be: @li @ref error::end_of_stream if no bytes were parsed, or @li @ref error::partial_message if any bytes were parsed but the message was incomplete, otherwise: @li A successful result. The next attempt to read will return @ref error::end_of_stream @param stream The stream from which the data is to be read. The type must meet the <em>SyncReadStream</em> requirements. @param buffer Storage for additional bytes read by the implementation from the stream. This is both an input and an output parameter; on entry, the parser will be presented with any remaining data in the dynamic buffer's readable bytes sequence first. The type must meet the <em>DynamicBuffer</em> requirements. @param parser The parser to use. @return The number of bytes transferred from the stream. @throws system_error Thrown on failure. @note The function returns the total number of bytes transferred from the stream. This may be zero for the case where there is sufficient pre-existing message data in the dynamic buffer. The implementation will call @ref basic_parser::eager with the value `true` on the parser passed in. */ template< class SyncReadStream, class DynamicBuffer, bool isRequest> std::size_t read( SyncReadStream& stream, DynamicBuffer& buffer, basic_parser<isRequest>& parser); /** Read a complete message from a stream using a parser. This function is used to read a complete message from a stream into an instance of @ref basic_parser. The call will block until one of the following conditions is true: @li @ref basic_parser::is_done returns `true` @li An error occurs. This operation is implemented in terms of one or more calls to the stream's `read_some` function. The implementation may read additional bytes from the stream that lie past the end of the message being read. These additional bytes are stored in the dynamic buffer, which must be preserved for subsequent reads. If the end of file error is received while reading from the stream, then the error returned from this function will be: @li @ref error::end_of_stream if no bytes were parsed, or @li @ref error::partial_message if any bytes were parsed but the message was incomplete, otherwise: @li A successful result. The next attempt to read will return @ref error::end_of_stream @param stream The stream from which the data is to be read. The type must meet the <em>SyncReadStream</em> requirements. @param buffer Storage for additional bytes read by the implementation from the stream. This is both an input and an output parameter; on entry, the parser will be presented with any remaining data in the dynamic buffer's readable bytes sequence first. The type must meet the <em>DynamicBuffer</em> requirements. @param parser The parser to use. @param ec Set to the error, if any occurred. @return The number of bytes transferred from the stream. @note The function returns the total number of bytes transferred from the stream. This may be zero for the case where there is sufficient pre-existing message data in the dynamic buffer. The implementation will call @ref basic_parser::eager with the value `true` on the parser passed in. */ template< class SyncReadStream, class DynamicBuffer, bool isRequest> std::size_t read( SyncReadStream& stream, DynamicBuffer& buffer, basic_parser<isRequest>& parser, error_code& ec); /** Read a complete message asynchronously from a stream using a parser. This function is used to asynchronously read a complete message from a stream into an instance of @ref basic_parser. The function call always returns immediately. The asynchronous operation will continue until one of the following conditions is true: @li @ref basic_parser::is_done returns `true` @li An error occurs. This operation is implemented in terms of zero or more calls to the next layer's `async_read_some` function, and is known as a <em>composed operation</em>. The program must ensure that the stream performs no other reads until this operation completes. The implementation may read additional bytes from the stream that lie past the end of the message being read. These additional bytes are stored in the dynamic buffer, which must be preserved for subsequent reads. If the end of file error is received while reading from the stream, then the error returned from this function will be: @li @ref error::end_of_stream if no bytes were parsed, or @li @ref error::partial_message if any bytes were parsed but the message was incomplete, otherwise: @li A successful result. The next attempt to read will return @ref error::end_of_stream @param stream The stream from which the data is to be read. The type must meet the <em>AsyncReadStream</em> requirements. @param buffer Storage for additional bytes read by the implementation from the stream. This is both an input and an output parameter; on entry, the parser will be presented with any remaining data in the dynamic buffer's readable bytes sequence first. The type must meet the <em>DynamicBuffer</em> requirements. The object must remain valid at least until the handler is called; ownership is not transferred. @param parser The parser to use. The object must remain valid at least until the handler is called; ownership is not transferred. @param handler The completion handler to invoke when the operation completes. The implementation takes ownership of the handler by performing a decay-copy. The equivalent function signature of the handler must be: @code void handler( error_code const& error, // result of operation std::size_t bytes_transferred // the total number of bytes transferred from the stream ); @endcode Regardless of whether the asynchronous operation completes immediately or not, the handler will not be invoked from within this function. Invocation of the handler will be performed in a manner equivalent to using `net::post`. @note The completion handler will receive as a parameter the total number of bytes transferred from the stream. This may be zero for the case where there is sufficient pre-existing message data in the dynamic buffer. The implementation will call @ref basic_parser::eager with the value `true` on the parser passed in. @par Per-Operation Cancellation This asynchronous operation supports cancellation for the following net::cancellation_type values: @li @c net::cancellation_type::terminal if the `stream` also supports terminal cancellation. `terminal` cancellation leaves the stream in an undefined state, so that only closing it is guaranteed to succeed. */ template< class AsyncReadStream, class DynamicBuffer, bool isRequest, BOOST_BEAST_ASYNC_TPARAM2 ReadHandler = net::default_completion_token_t< executor_type<AsyncReadStream>>> BOOST_BEAST_ASYNC_RESULT2(ReadHandler) async_read( AsyncReadStream& stream, DynamicBuffer& buffer, basic_parser<isRequest>& parser, ReadHandler&& handler = net::default_completion_token_t< executor_type<AsyncReadStream>>{}); //------------------------------------------------------------------------------ /** Read a complete message from a stream. This function is used to read a complete message from a stream into an instance of @ref message. The call will block until one of the following conditions is true: @li The entire message is read in. @li An error occurs. This operation is implemented in terms of one or more calls to the stream's `read_some` function. The implementation may read additional bytes from the stream that lie past the end of the message being read. These additional bytes are stored in the dynamic buffer, which must be preserved for subsequent reads. If the end of file error is received while reading from the stream, then the error returned from this function will be: @li @ref error::end_of_stream if no bytes were parsed, or @li @ref error::partial_message if any bytes were parsed but the message was incomplete, otherwise: @li A successful result. The next attempt to read will return @ref error::end_of_stream @param stream The stream from which the data is to be read. The type must meet the <em>SyncReadStream</em> requirements. @param buffer Storage for additional bytes read by the implementation from the stream. This is both an input and an output parameter; on entry, the parser will be presented with any remaining data in the dynamic buffer's readable bytes sequence first. The type must meet the <em>DynamicBuffer</em> requirements. @param msg The container in which to store the message contents. This message container should not have previous contents, otherwise the behavior is undefined. The type must be meet the <em>MoveAssignable</em> and <em>MoveConstructible</em> requirements. @return The number of bytes transferred from the stream. @throws system_error Thrown on failure. @note The function returns the total number of bytes transferred from the stream. This may be zero for the case where there is sufficient pre-existing message data in the dynamic buffer. The implementation will call @ref basic_parser::eager with the value `true` on the parser passed in. */ template< class SyncReadStream, class DynamicBuffer, bool isRequest, class Body, class Allocator> std::size_t read( SyncReadStream& stream, DynamicBuffer& buffer, message<isRequest, Body, basic_fields<Allocator>>& msg); /** Read a complete message from a stream. This function is used to read a complete message from a stream into an instance of @ref message. The call will block until one of the following conditions is true: @li The entire message is read in. @li An error occurs. This operation is implemented in terms of one or more calls to the stream's `read_some` function. The implementation may read additional bytes from the stream that lie past the end of the message being read. These additional bytes are stored in the dynamic buffer, which must be preserved for subsequent reads. If the end of file error is received while reading from the stream, then the error returned from this function will be: @li @ref error::end_of_stream if no bytes were parsed, or @li @ref error::partial_message if any bytes were parsed but the message was incomplete, otherwise: @li A successful result. The next attempt to read will return @ref error::end_of_stream @param stream The stream from which the data is to be read. The type must meet the <em>SyncReadStream</em> requirements. @param buffer Storage for additional bytes read by the implementation from the stream. This is both an input and an output parameter; on entry, the parser will be presented with any remaining data in the dynamic buffer's readable bytes sequence first. The type must meet the <em>DynamicBuffer</em> requirements. @param msg The container in which to store the message contents. This message container should not have previous contents, otherwise the behavior is undefined. The type must be meet the <em>MoveAssignable</em> and <em>MoveConstructible</em> requirements. @param ec Set to the error, if any occurred. @return The number of bytes transferred from the stream. @note The function returns the total number of bytes transferred from the stream. This may be zero for the case where there is sufficient pre-existing message data in the dynamic buffer. The implementation will call @ref basic_parser::eager with the value `true` on the parser passed in. */ template< class SyncReadStream, class DynamicBuffer, bool isRequest, class Body, class Allocator> std::size_t read( SyncReadStream& stream, DynamicBuffer& buffer, message<isRequest, Body, basic_fields<Allocator>>& msg, error_code& ec); /** Read a complete message asynchronously from a stream. This function is used to asynchronously read a complete message from a stream into an instance of @ref message. The function call always returns immediately. The asynchronous operation will continue until one of the following conditions is true: @li The entire message is read in. @li An error occurs. This operation is implemented in terms of zero or more calls to the next layer's `async_read_some` function, and is known as a <em>composed operation</em>. The program must ensure that the stream performs no other reads until this operation completes. The implementation may read additional bytes from the stream that lie past the end of the message being read. These additional bytes are stored in the dynamic buffer, which must be preserved for subsequent reads. If the end of file error is received while reading from the stream, then the error returned from this function will be: @li @ref error::end_of_stream if no bytes were parsed, or @li @ref error::partial_message if any bytes were parsed but the message was incomplete, otherwise: @li A successful result. The next attempt to read will return @ref error::end_of_stream @param stream The stream from which the data is to be read. The type must meet the <em>AsyncReadStream</em> requirements. @param buffer Storage for additional bytes read by the implementation from the stream. This is both an input and an output parameter; on entry, the parser will be presented with any remaining data in the dynamic buffer's readable bytes sequence first. The type must meet the <em>DynamicBuffer</em> requirements. The object must remain valid at least until the handler is called; ownership is not transferred. @param msg The container in which to store the message contents. This message container should not have previous contents, otherwise the behavior is undefined. The type must be meet the <em>MoveAssignable</em> and <em>MoveConstructible</em> requirements. The object must remain valid at least until the handler is called; ownership is not transferred. @param handler The completion handler to invoke when the operation completes. The implementation takes ownership of the handler by performing a decay-copy. The equivalent function signature of the handler must be: @code void handler( error_code const& error, // result of operation std::size_t bytes_transferred // the total number of bytes transferred from the stream ); @endcode Regardless of whether the asynchronous operation completes immediately or not, the handler will not be invoked from within this function. Invocation of the handler will be performed in a manner equivalent to using `net::post`. @note The completion handler will receive as a parameter the total number of bytes transferred from the stream. This may be zero for the case where there is sufficient pre-existing message data in the dynamic buffer. The implementation will call @ref basic_parser::eager with the value `true` on the parser passed in. @par Per-Operation Cancellation This asynchronous operation supports cancellation for the following net::cancellation_type values: @li @c net::cancellation_type::terminal if the `stream` also supports terminal cancellation. `terminal` cancellation leaves the stream in an undefined state, so that only closing it is guaranteed to succeed. */ template< class AsyncReadStream, class DynamicBuffer, bool isRequest, class Body, class Allocator, BOOST_BEAST_ASYNC_TPARAM2 ReadHandler = net::default_completion_token_t< executor_type<AsyncReadStream>>> BOOST_BEAST_ASYNC_RESULT2(ReadHandler) async_read( AsyncReadStream& stream, DynamicBuffer& buffer, message<isRequest, Body, basic_fields<Allocator>>& msg, ReadHandler&& handler = net::default_completion_token_t< executor_type<AsyncReadStream>>{}); } // http } // beast } // boost #include <boost/beast/http/impl/read.hpp> #endif