Body (webs.Webs.Http.Body)

Bytes readers and writers

type byte_reader = unit -> (bytes * int * int) option

The type for reading bytes. Pull control flow.

The function returns Some (bytes, first, length) for letting the client read bytes from first to first+length valid until the next call to the function. The bytes value must not be modified by the client.
The function returns None when there are no longer any bytes to read and subsequent calls always return None.

type byte_writer = (bytes * int * int) option -> unit

The type for writing bytes. Push control flow.

The function should be called with Some (byte, first, length) to write the bytes from first to first+length. These bytes should not be modified until the function returns and the function must only read the given bytes.
The function gets called with None to signal that there is no longer any bytes to write.

Body contents

type 'a writer = 'a -> unit

The type for body writers. These are functions defining bodies by writing them on the structure 'a given to them. Typically for service responses the connector provides a structure to write on.

type custom_content = ..

The type for custom body contents.

This allows bodies to expose connector specific readable or writable representations. For example the Webs_unix.Fd.Writer custom content defines a body content by a function that writes directly on an output file descriptor provided by the connector.

type content =

| Empty
(*
Empty body.
*)
| Byte_reader of byte_reader
(*
Byte reader, pulls bytes.
*)
| Byte_writer of byte_writer writer
(*
Function that pushes bytes.
*)
| Custom of custom_content
(*
Custom content.
*)

The type for body contents.

Bodies

type t

The type for bodies.

val make : ?content_length:int -> ?content_type:Media_type.t -> content -> t

make c is a body with content c and

content_type the content type. Defaults to Media_type.application_octet_stream.
content_length the content length in bytes, if known. Defaults to None

Raises Invalid_argument if content_length is negative.

val empty : t

empty s is a body with Empty content. The content_type is Media_type.none, the content_length is 0 and close is a nop.

val of_custom_content : 
  ?content_length:int ->
  ?content_type:Media_type.t ->
  custom_content ->
  t

of_custom_content c is a body defined by the custom content c.

val of_byte_writer : 
  ?content_length:int ->
  ?content_type:Media_type.t ->
  byte_writer writer ->
  t

of_byte_writer w is a body written by w.

val of_byte_reader : 
  ?content_length:int ->
  ?content_type:Media_type.t ->
  byte_reader ->
  t

of_byte_reader b is a body from the given byte reader.

val of_string : ?content_type:Media_type.t -> string -> t

of_string s is a body made of string s (uses a Byte_writer). content_length is set to the length of s.

val to_byte_reader : t -> (byte_reader, string) Stdlib.result

to_byte_reader b is a byte reader on the inbound body b. This errors on Custom content. It works on Byte_writer but entails a full copy in memory.

val to_string : t -> (string, string) Stdlib.result

to_string b reads the body to a string. This errors on Custom content.

val pp : Stdlib.Format.formatter -> t -> unit

pp formats bodies for inspection. It guarantees not to touch the content.

Operations

Predicates

val is_empty : t -> bool

is_empty b is true iff content b is Empty. Note that this does not rule out a writer that doesn't write any data.

Properties

val content : t -> content

content b is the content of b.

val content_type : t -> Media_type.t

content_type b is the media type of b.

val content_length : t -> int option

content_length b is the content length of b, if known.