mte/unikernel/duniverse/httpun/lib/httpun.mli
2025-11-11 02:07:51 +01:00

462 lines
18 KiB
OCaml

(*----------------------------------------------------------------------------
Copyright (c) 2017 Inhabited Type LLC.
Copyright (c) 2019 Antonio Nuno Monteiro.
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
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notice, this list of conditions and the following disclaimer.
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documentation and/or other materials provided with the distribution.
3. Neither the name of the author nor the names of his contributors
may be used to endorse or promote products derived from this software
without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND ANY EXPRESS
OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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----------------------------------------------------------------------------*)
(** httpun is a high-performance, memory-efficient, and scalable HTTP/1.x
library for OCaml. It implements the HTTP 1.1 specification with respect to
parsing, serialization, and pipelining. *)
(** {2 Basic HTTP Types} *)
module IOVec : module type of Httpun_types.IOVec
module Version : module type of Httpun_types.Version
module Method : module type of Httpun_types.Method
module Status : module type of Httpun_types.Status
module Headers : module type of Httpun_types.Headers
(** {2 Message Body} *)
module Body : sig
module Reader : sig
type t
val schedule_read
: t
-> on_eof : (unit -> unit)
-> on_read : (Bigstringaf.t -> off:int -> len:int -> unit)
-> unit
(** [schedule_read t ~on_eof ~on_read] will setup [on_read] and [on_eof] as
callbacks for when bytes are available in [t] for the application to
consume, or when the input channel has been closed and no further bytes
will be received by the application.
Once either of these callbacks have been called, they become inactive.
The application is responsible for scheduling subsequent reads, either
within the [on_read] callback or by some other mechanism. *)
val close : t -> unit
(** [close t] closes [t], indicating that any subsequent input
received should be discarded. *)
val is_closed : t -> bool
(** [is_closed t] is [true] if {!close} has been called on [t] and [false]
otherwise. A closed [t] may still have bytes available for reading. *)
end
module Writer : sig
type t
val write_char : t -> char -> unit
(** [write_char w char] copies [char] into an internal buffer. If possible,
this write will be combined with previous and/or subsequent writes
before transmission. *)
val write_string : t -> ?off:int -> ?len:int -> string -> unit
(** [write_string w ?off ?len str] copies [str] into an internal buffer. If
possible, this write will be combined with previous and/or subsequent
writes before transmission. *)
val write_bigstring : t -> ?off:int -> ?len:int -> Bigstringaf.t -> unit
(** [write_bigstring w ?off ?len bs] copies [bs] into an internal buffer. If
possible, this write will be combined with previous and/or subsequent
writes before transmission. *)
val schedule_bigstring : t -> ?off:int -> ?len:int -> Bigstringaf.t -> unit
(** [schedule_bigstring w ?off ?len bs] schedules [bs] to be transmitted at
the next opportunity without performing a copy. [bs] should not be
modified until a subsequent call to {!flush} has successfully
completed. *)
val flush : t -> ([ `Written | `Closed ] -> unit) -> unit
(** [flush t f] makes all bytes in [t] available for writing to the
awaiting output channel. Once those bytes have reached that output
channel, [f `Written] will be called. If instead, the output channel is
closed before all of those bytes are successfully written, [f `Closed]
will be called.
The type of the output channel is runtime-dependent, as are guarantees
about whether those packets have been queued for delivery or have
actually been received by the intended recipient. *)
val close : t -> unit
(** [close t] closes [t], causing subsequent write calls to raise. If
[t] is writable, this will cause any pending output to become available
to the output channel. *)
val is_closed : t -> bool
(** [is_closed t] is [true] if {!close} has been called on [t], or if the
attached output channel is closed (e.g. because [report_write_result
`Closed] has been called). A closed [t] may still have pending output. *)
end
end
(** {2 Message Types} *)
(** Request
A client-initiated HTTP message. *)
module Request : sig
type t =
{ meth : Method.t
; target : string
; version : Version.t
; headers : Headers.t }
val create
: ?version:Version.t (** default is HTTP 1.1 *)
-> ?headers:Headers.t (** default is {!Headers.empty} *)
-> Method.t
-> string
-> t
module Body_length : sig
type t = [
| `Fixed of Int64.t
| `Chunked
| `Error of [`Bad_request]
]
val pp_hum : Format.formatter -> t -> unit
end
val body_length : t -> Body_length.t
(** [body_length t] is the length of the message body accompanying [t]. It is
an error to generate a request with a close-delimited message body.
See {{:https://tools.ietf.org/html/rfc7230#section-3.3.3} RFC7230§3.3.3}
for more details. *)
val persistent_connection : ?proxy:bool -> t -> bool
(** [persistent_connection ?proxy t] indicates whether the connection for [t]
can be reused for multiple requests and responses. If the calling code
is acting as a proxy, it should pass [~proxy:true].
See {{:https://tools.ietf.org/html/rfc7230#section-6.3} RFC7230§6.3 for
more details. *)
val pp_hum : Format.formatter -> t -> unit [@@ocaml.toplevel_printer]
end
(** Response
A server-generated message to a {Request}. *)
module Response : sig
type t =
{ version : Version.t
; status : Status.t
; reason : string
; headers : Headers.t }
val create
: ?reason:string (** default is determined by {!Status.default_reason_phrase} *)
-> ?version:Version.t (** default is HTTP 1.1 *)
-> ?headers:Headers.t (** default is {!Headers.empty} *)
-> Status.t
-> t
(** [create ?reason ?version ?headers status] creates an HTTP response with
the given parameters. For typical use cases, it's sufficient to provide
values for [headers] and [status]. *)
module Body_length : sig
type t = [
| `Fixed of Int64.t
| `Chunked
| `Close_delimited
| `Error of [ `Bad_gateway | `Internal_server_error ]
]
val pp_hum : Format.formatter -> t -> unit
end
val body_length : ?proxy:bool -> request_method:Method.standard -> t -> Body_length.t
(** [body_length ?proxy ~request_method t] is the length of the message body
accompanying [t] assuming it is a response to a request whose method was
[request_method]. If the calling code is acting as a proxy, it should
pass [~proxy:true]. This optional parameter only affects error reporting.
See {{:https://tools.ietf.org/html/rfc7230#section-3.3.3} RFC7230§3.3.3}
for more details. *)
val persistent_connection : ?proxy:bool -> t -> bool
(** [persistent_connection ?proxy t] indicates whether the connection for [t]
can be reused for multiple requests and responses. If the calling code
is acting as a proxy, it should pass [~proxy:true].
See {{:https://tools.ietf.org/html/rfc7230#section-6.3} RFC7230§6.3 for
more details. *)
val pp_hum : Format.formatter -> t -> unit [@@ocaml.toplevel_printer]
end
(** {2 Request Descriptor} *)
module Reqd : sig
type t
type error =
[ `Bad_request | `Bad_gateway | `Internal_server_error | `Exn of exn ]
val request : t -> Request.t
val request_body : t -> Body.Reader.t
val response : t -> Response.t option
val response_exn : t -> Response.t
(** Responding
The following functions will initiate a response for the corresponding
request in [t]. Depending on the state of the current connection, and the
header values of the response, this may cause the connection to close or
to persist for reuse by the client.
See {{:https://tools.ietf.org/html/rfc7230#section-6.3} RFC7230§6.3} for
more details. *)
val respond_with_string : t -> Response.t -> string -> unit
val respond_with_bigstring : t -> Response.t -> Bigstringaf.t -> unit
val respond_with_streaming : ?flush_headers_immediately:bool -> t -> Response.t -> Body.Writer.t
val respond_with_upgrade : t -> Headers.t -> (unit -> unit) -> unit
(** {3 Exception Handling} *)
val error_code : t -> error option
val report_exn : t -> exn -> unit
val try_with : t -> (unit -> unit) -> (unit, exn) result
end
(** {2 Buffer Size Configuration} *)
module Config : sig
type t =
{ read_buffer_size : int (** Default is [4096] *)
; request_body_buffer_size : int (** Default is [4096] *)
; response_buffer_size : int (** Default is [1024] *)
; response_body_buffer_size : int (** Default is [4096] *)
}
val default : t
(** [default] is a configuration record with all parameters set to their
default values. *)
end
(** {2 Server Connection} *)
module Server_connection : sig
type t
type error = Reqd.error
type request_handler = Reqd.t -> unit
type error_handler =
?request:Request.t -> error -> (Headers.t -> Body.Writer.t) -> unit
val create
: ?config:Config.t
-> ?error_handler:error_handler
-> request_handler
-> t
(** [create ?config ?error_handler ~request_handler] creates a connection
handler that will service individual requests with [request_handler]. *)
val next_read_operation : t -> [ `Read | `Yield | `Close ]
(** [next_read_operation t] returns a value describing the next operation
that the caller should conduct on behalf of the connection. *)
val read : t -> Bigstringaf.t -> off:int -> len:int -> int
(** [read t bigstring ~off ~len] reads bytes of input from the provided range
of [bigstring] and returns the number of bytes consumed by the
connection. {!read} should be called after {!next_read_operation}
returns a [`Read] value and additional input is available for the
connection to consume. *)
val read_eof : t -> Bigstringaf.t -> off:int -> len:int -> int
(** [read_eof t bigstring ~off ~len] reads bytes of input from the provided
range of [bigstring] and returns the number of bytes consumed by the
connection. {!read_eof} should be called after {!next_read_operation}
returns a [`Read] and an EOF has been received from the communication
channel. The connection will attempt to consume any buffered input and
then shutdown the HTTP parser for the connection. *)
val yield_reader : t -> (unit -> unit) -> unit
(** [yield_reader t continue] registers with the connection to call
[continue] when reading should resume. {!yield_reader} should be called
after {next_read_operation} returns a [`Yield] value. *)
val next_write_operation : t -> [
| `Write of Bigstringaf.t IOVec.t list
| `Yield
| `Close of int ]
(** [next_write_operation t] returns a value describing the next operation
that the caller should conduct on behalf of the connection. *)
val report_write_result : t -> [`Ok of int | `Closed] -> unit
(** [report_write_result t result] reports the result of the latest write
attempt to the connection. {report_write_result} should be called after a
call to {next_write_operation} that returns a [`Write buffer] value.
{ul
{- [`Ok n] indicates that the caller successfully wrote [n] bytes of
output from the buffer that the caller was provided by
{next_write_operation}. }
{- [`Closed] indicates that the output destination will no longer
accept bytes from the write processor. }} *)
val yield_writer : t -> (unit -> unit) -> unit
(** [yield_writer t continue] registers with the connection to call
[continue] when writing should resume. {!yield_writer} should be called
after {next_write_operation} returns a [`Yield] value. *)
val report_exn : t -> exn -> unit
(** [report_exn t exn] reports that an error [exn] has been caught and
that it has been attributed to [t]. Calling this function will switch [t]
into an error state. Depending on the state [t] is transitioning from, it
may call its error handler before terminating the connection. *)
val is_closed : t -> bool
(** [is_closed t] is [true] if both the read and write processors have been
shutdown. When this is the case {!next_read_operation} will return
[`Close _] and {!next_write_operation} will return [`Write _] until all
buffered output has been flushed. *)
val error_code : t -> error option
(** [error_code t] returns the [error_code] that caused the connection to
close, if one exists. *)
(**/**)
val shutdown : t -> unit
(**/**)
end
(** {2 Client Connection} *)
module Client_connection : sig
type t
type error =
[ `Malformed_response of string | `Invalid_response_body_length of Response.t | `Exn of exn ]
type response_handler = Response.t -> Body.Reader.t -> unit
type error_handler = error -> unit
val create : ?config:Config.t -> unit -> t
val request
: t
-> ?flush_headers_immediately:bool
-> Request.t
-> error_handler:error_handler
-> response_handler:response_handler
-> Body.Writer.t
val next_read_operation : t -> [ `Read | `Yield | `Close ]
(** [next_read_operation t] returns a value describing the next operation
that the caller should conduct on behalf of the connection. *)
val read : t -> Bigstringaf.t -> off:int -> len:int -> int
(** [read t bigstring ~off ~len] reads bytes of input from the provided range
of [bigstring] and returns the number of bytes consumed by the
connection. {!read} should be called after {!next_read_operation}
returns a [`Read] value and additional input is available for the
connection to consume. *)
val read_eof : t -> Bigstringaf.t -> off:int -> len:int -> int
(** [read_eof t bigstring ~off ~len] reads bytes of input from the provided
range of [bigstring] and returns the number of bytes consumed by the
connection. {!read_eof} should be called after {!next_read_operation}
returns a [`Read] and an EOF has been received from the communication
channel. The connection will attempt to consume any buffered input and
then shutdown the HTTP parser for the connection. *)
val next_write_operation : t -> [
| `Write of Bigstringaf.t IOVec.t list
| `Yield
| `Close of int ]
(** [next_write_operation t] returns a value describing the next operation
that the caller should conduct on behalf of the connection. *)
val report_write_result : t -> [`Ok of int | `Closed] -> unit
(** [report_write_result t result] reports the result of the latest write
attempt to the connection. {report_write_result} should be called after a
call to {next_write_operation} that returns a [`Write buffer] value.
{ul
{- [`Ok n] indicates that the caller successfully wrote [n] bytes of
output from the buffer that the caller was provided by
{next_write_operation}. }
{- [`Closed] indicates that the output destination will no longer
accept bytes from the write processor. }} *)
val yield_reader : t -> (unit -> unit) -> unit
val yield_writer : t -> (unit -> unit) -> unit
(** [yield_writer t continue] registers with the connection to call
[continue] when writing should resume. {!yield_writer} should be called
after {next_write_operation} returns a [`Yield] value. *)
val report_exn : t -> exn -> unit
(** [report_exn t exn] reports that an error [exn] has been caught and
that it has been attributed to [t]. Calling this function will switch [t]
into an error state. Depending on the state [t] is transitioning from, it
may call its error handler before terminating the connection. *)
val is_closed : t -> bool
(** [is_closed t] is [true] if both the read and write processors have been
shutdown. When this is the case {!next_read_operation} will return
[`Close _] and {!next_write_operation} will return [`Write _] until all
buffered output has been flushed, at which point it will also return
`Close. *)
val shutdown : t -> unit
(** [shutdown connection] closes the underlying input and output channels of
the connection, rendering it unusable for any further communication. *)
end
(**/**)
module Httpun_private : sig
module Parse : sig
val request : Request.t Angstrom.t
val response : Response.t Angstrom.t
end
module Serialize : sig
val write_request : Faraday.t -> Request.t -> unit
val write_response : Faraday.t -> Response.t -> unit
end
end