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http::basic_parser

A parser for decoding HTTP/1 wire format messages.

Synopsis

Defined in header <boost/beast/http/basic_parser.hpp>

template<
    bool isRequest>
class basic_parser :
    private basic_parser_base
Types

Name

Description

is_request

true if this parser parses requests, false for responses.

Member Functions

Name

Description

basic_parser

Copy constructor.

body_limit

Set the limit on the payload body.

chunked

Returns true if the last value for Transfer-Encoding is "chunked".

content_length

Returns the optional value of Content-Length if known.

content_length_remaining

Returns the remaining content length if known.

eager

Returns true if the eager parse option is set.

Set the eager parse option.

got_some

Returns true if the parser has received at least one byte of input.

header_limit

Set a limit on the total size of the header.

is_done

Returns true if the message is complete.

is_header_done

Returns true if a the parser has produced the full header.

keep_alive

Returns true if the message has keep-alive connection semantics.

need_eof

Returns true if the message semantics require an end of file.

operator=

Copy assignment.

put

Write a buffer sequence to the parser.

put_eof

Inform the parser that the end of stream was reached.

skip

Returns true if the skip parse option is set.

Set the skip parse option.

upgrade

Returns true if the message is an upgrade message.

~basic_parser

Destructor.

Protected Member Functions

Name

Description

basic_parser

Default constructor.

Move constructor.

on_body_impl

Called each time additional data is received representing the content body.

on_body_init_impl

Called once before the body is processed.

on_chunk_body_impl

Called each time additional data is received representing part of a body chunk.

on_chunk_header_impl

Called each time a new chunk header of a chunk encoded body is received.

on_field_impl

Called once for each complete field in the HTTP header.

on_finish_impl

Called once when the complete message is received.

on_header_impl

Called once after the complete HTTP header is received.

on_request_impl

Called after receiving the request-line.

on_response_impl

Called after receiving the status-line.

operator=

Move assignment.

Description

This parser is designed to efficiently parse messages in the HTTP/1 wire format. It allocates no memory when input is presented as a single contiguous buffer, and uses minimal state. It will handle chunked encoding and it understands the semantics of the Connection, Content-Length, and Upgrade fields. The parser is optimized for the case where the input buffer sequence consists of a single contiguous buffer. The basic_flat_buffer class is provided, which guarantees that the input sequence of the stream buffer will be represented by exactly one contiguous buffer. To ensure the optimum performance of the parser, use basic_flat_buffer with HTTP algorithms such as http::read, http::read_some, http::async_read, and http::async_read_some. Alternatively, the caller may use custom techniques to ensure that the structured portion of the HTTP message (header or chunk header) is contained in a linear buffer. The interface to the parser uses virtual member functions. To use this class, derive your type from http::basic_parser. When bytes are presented, the implementation will make a series of zero or more calls to virtual functions, which the derived class must implement. Every virtual function must be provided by the derived class, or else a compilation error will be generated. The implementation will make sure that ec is clear before each virtual function is invoked. If a virtual function sets an error, it is propagated out of the parser to the caller.

Template Parameters

Type

Description

isRequest

A bool indicating whether the parser will be presented with request or response message.

Remarks

If the parser encounters a field value with obs-fold longer than 4 kilobytes in length, an error is generated.

Convenience header <boost/beast/http.hpp>


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