http::read (2 of 4 overloads)

Read a complete message from a stream using a parser.

Synopsis

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

template<
    class SyncReadStream,
    class DynamicBuffer,
    bool isRequest>
std::size_t
read(
    SyncReadStream& stream,
    DynamicBuffer& buffer,
    basic_parser< isRequest >& parser,
    error_code& ec);

Description

This function is used to read a complete message from a stream into an instance of basic_parser. The call will block until one of the following conditions is true:

basic_parser::is_done returns true
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:

error::end_of_stream if no bytes were parsed, or
error::partial_message if any bytes were parsed but the message was incomplete, otherwise:
A successful result. The next attempt to read will return error::end_of_stream

Parameters

Name	Description
`stream`	The stream from which the data is to be read. The type must meet the SyncReadStream requirements.
`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 DynamicBuffer requirements.
`parser`	The parser to use.
`ec`	Set to the error, if any occurred.

Return Value

The number of bytes transferred from the stream.

Remarks

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 basic_parser::eager with the value true on the parser passed in.