Source file iOVec.ml

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type 'a t = 'a Faraday.iovec =
  { buffer : 'a
  ; off : int
  ; len : int }

let length { len; _ } = len
let lengthv iovs = List.fold_left (fun acc { len; _ } -> acc + len) 0 iovs

let shift { buffer; off; len } n =
  assert (n <= len);
  { buffer; off = off + n; len = len - n }

let shiftv iovecs n =
  if n < 0 then failwith (Printf.sprintf "IOVec.shiftv: %d is a negative number" n);
  let rec loop iovecs n =
    if n = 0
    then iovecs
    else match iovecs with
    | []            -> failwith "shiftv: n > lengthv iovecs"
    | iovec::iovecs ->
      let iovec_len = length iovec in
      if iovec_len <= n
      then loop iovecs (n - iovec_len)
      else (shift iovec n)::iovecs
  in
  loop iovecs n

let add_len { buffer; off; len } n =
  { buffer; off; len = len + n }

let pp_hum fmt t =
  Format.fprintf fmt "{ buffer = <opaque>; off = %d; len = %d }" t.off t.len