HTTP Messages

Header, body and progress of HTTP messages. More...

Classes
class	Credential
	Credentials for authorization and authentication. More...
class	HttpError
	HTTP run-time error. More...
class	MessageHeader
	HTTP message header. More...
class	MessageProgress
	Progress of an asynchronous HTTP send or receive. More...
class	Message
	HTTP message with header and body. More...
class	Reply
	HTTP reply message. More...
class	Request
	HTTP request message. More...

Detailed Description

An HTTP message is a header and an optional body. The header is a list of name and value fields together with the HTTP version, and the body is a byte stream. Message holds both. Request and Reply are messages: a request adds the method, the URL and the query string, while a reply adds the status code and the status text.

Callers do not normally construct these types. A Client owns the request it will send and the reply it receives, and a Responder is given the server-side request and reply for one exchange, so the same header and body operations apply on both sides.

MessageHeader stores fields in a fixed buffer. set() replaces a field, add() appends another value for the same name, and get() and has() look up a name. begin() and end() walk the fields. Keep-alive, chunked transfer coding, content length and Upgrade are derived from those fields rather than being a second header model.

body() is a bidirectional stream on the message. Write to it to fill a request or a reply that will be sent, and read from it when a receive step has delivered body bytes. discard() drops buffered body data. available() and pending() report how much can be read or still has to be written.

Asynchronous send and receive move a message in steps, and each completed step returns a MessageProgress value. header() is true when the header of that message is available, body() is true when body bytes were processed, and finished() is true when the message is complete. A short message often sets all three on one step, while a long body, or a send that only partly left the socket, needs another begin and end pair. Progress can also be empty, meaning the step made I/O progress without exposing a header or a body yet, in which case the next begin call continues the same message.

HttpError is the HTTP-specific I/O error. Credential is a user name and password that client authentication and server authorization both use, though they do not use the same authenticator type.