Source file message.ml

(*----------------------------------------------------------------------------
 *  Copyright (c) 2017 Inhabited Type LLC.
 *  Copyright (c) 2019 Antonio N. 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:
 *
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     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)
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 *  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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 *---------------------------------------------------------------------------*)

(* This module contains functionality that applies to both requests and
 * responses, which are collectively referred to in the HTTP 1.1 specifications
 * as 'messages'. *)

let sort_uniq xs =
  (* Though {!List.sort_uniq} performs a check on the input length and returns
   * immediately for lists of length less than [2], it still allocates closures
   * before it does that check! To avoid that just do our own checking here to
   * avoid the allocations in the common case. *)
  match xs with [] | [ _ ] -> xs | _ -> List.sort_uniq String.compare xs

let unique_content_length_values headers =
  (* XXX(seliopou): perform proper content-length parsing *)
  sort_uniq (Headers.get_multi headers "content-length")

let content_length_of_string s = try Int64.of_string s with _ -> -1L

let body_length headers =
  match unique_content_length_values headers with
  | [ len ] ->
    let len = content_length_of_string len in
    if Int64.compare len 0L >= 0 then
      `Fixed len
    else
      `Error `Bad_request
  | _ ->
    `Unknown