class type http_response =
Encapsultation of the HTTP response for a single request
Represents the action of sending the response
This class has an internal
queue of response tokens that are not yet processed. One can easily add
new tokens to the end of the queue (
The class is responsible for determining the transfer encoding:
- When the HTTP version is 1.0, the encoding is always "identity", and the
connection will be closed after the response.
- When the HTTP version is 1.1, and there is a Content-length header,
the encoding will be selected as "identity". It is checked whether the
body has really this length. If too short, it is suggested to close
the connection. If too long, the extra part of the message is silently
- When the HTTP version is 1.1, and there is no Content-length header,
the encoding will be selected as "chunked".
request header is not taken into account. The trailer
is always empty.
The following headers are set (or removed) by this class:
Server (it is appended to this field)
Responses for HEAD requests have the special behaviour that the body is silently
dropped. The calculation of header fields is not affected by this. This means
that HEAD can be easily implemented by doing the same as for GET.
Responses for other requests that must not include a body must set
Content-Length to 0.
These methods can be called by the content provider:
method state :
Reports the state. The initial state is
method bidirectional_phase :
The bidrectional phase starts after "100 Continue" has been sent to the
client, and stops when the response body begins. The bidirectional phase
is special for the calculation of timeout values (input determines the timeout
although the response has started).
method send :
resp_token -> unit
Add token to the end of the send queue
method send_queue_empty :
Return whether the send queue is empty. When the state is
method fakes an empty queue.
method protocol :
The HTTP version of the response. This is currently always HTTP/1.1, but maybe
we need to fake lower versions for buggy clients. Let's see what comes.
method close_connection :
Returns whether the connection should be closed after this response.
This flag should be evaluated when the
`Resp_end front token has been
method transfer_encoding :
Returns the selected transfer encoding. This is valid after the header
has been passed to this object with
method front_token :
The first token of the queue, represented as
when there is currently no front token, or the state
If there is a front token, it will never have length 0.
Unix_error exceptions can be raised when
tokens are processed.
method set_callback :
(unit -> unit) -> unit
The function will be called when either
set_state changes the state,
or when the send queue becomes empty. Note that the callback must never
fail, it is called in situations that make it hard to recover from errors.
method body_size :
Accumulated size of the response body
These methods must only be called by the HTTP protocol processor:
method set_state :
resp_state -> unit
Sets the state
method advance :
int -> unit
Tell this object that
n bytes of the front token could be really
Unix.write. If this means that the whole front token
has been sent, the next token is pulled from the queue and is made
the new front token. Otherwise, the data chunk representing the
front token is modified such that the position is advanced by
n, and the length is reduced by