Source file util.ml

(*{{{
 * Copyright (C) 2015 Trevor Smith <trevorsummerssmith@gmail.com>
 * Copyright (C) 2018 Anders Fugmann <anders@fugmann.net>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
  }}}*)
open StdLabels

(* @see https://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-streaming.html
   public static String UriEncode(CharSequence input, boolean encodeSlash) {
          StringBuilder result = new StringBuilder();
          for (int i = 0; i < input.length(); i++) {
              char ch = input.charAt(i);
              if ((ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z') || (ch >= '0' && ch <= '9') || ch == '_' || ch == '-' || ch == '~' || ch == '.') {
                  result.append(ch);
              } else if (ch == '/') {
                  result.append(encodeSlash ? "%2F" : ch);
              } else {
                  result.append(toHexUTF8(ch));
              }
          }
          return result.toString();
      }
*)
let encode_string s =
  (* Percent encode the path as s3 wants it. Uri doesn't
       encode $, or the other sep characters in a path.
       If upstream allows that we can nix this function *)
  let n = String.length s in
  let buf = Buffer.create (n * 3) in
  for i = 0 to (n-1) do
    let c = String.get s i in
    match c with
    | 'a' .. 'z'
    | 'A' .. 'Z'
    | '0' .. '9'
    | '_' | '-' | '~' | '.' | '/' -> Buffer.add_char buf c
    | '%' ->
      (* Sigh. Annoying we're expecting already escaped strings so ignore the escapes *)
      begin
        let is_hex = function
          | 'a' .. 'f' | 'A' .. 'F' | '0' .. '9' -> true
          | _ -> false
        in
        if (i + 2) < n then
          if is_hex(String.get s (i+1)) && is_hex(String.get s (i+2)) then
            Buffer.add_char buf c
          else
            Buffer.add_string buf "%25"
      end
    | _ -> Buffer.add_string buf (Printf.sprintf "%%%X" (Char.code c))
  done;
  Buffer.contents buf