Source file odoc_file.ml

# 1 "src/odoc/odoc_file.cppo.ml"
(*
 * Copyright (c) 2014 Leo White <leo@lpw25.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 Odoc_utils
open ResultMonad
open Odoc_model

type unit_content = Lang.Compilation_unit.t

type content =
  | Page_content of Lang.Page.t
  | Impl_content of Lang.Implementation.t
  | Unit_content of unit_content
  | Asset_content of Lang.Asset.t

type t = { content : content; warnings : Odoc_model.Error.t list }

(** Written at the top of the files. Checked when loading. *)
(* Compress the marshalled payloads with the compiler's own [Compression]
   module (from compiler-libs.common) - the same mechanism it uses for
   .cmt/.cmti files. Payloads are zstd-compressed when the running compiler was
   built with zstd support, and fall back to plain Marshal otherwise.
   [Compression] only exists from OCaml 5.1 and is absent from OxCaml; there
   we use Marshal directly and the files stay as they were. *)
# 43 "src/odoc/odoc_file.cppo.ml"
let compression_supported = false
let output_value oc v = Marshal.to_channel oc v []
let input_value ic = Marshal.from_channel ic

# 48 "src/odoc/odoc_file.cppo.ml"
let magic = "ODOC"

(* A compressed payload can only be read back by a compiler with zstd support,
   so the version records which format was written: an odoc without it reports
   the mismatch here rather than failing in the unmarshaller with "compressed
   object, cannot decompress". *)
let magic_version_uncompressed = "3.2.1-177-g63708bb"

let magic_version =
  magic_version_uncompressed ^ if compression_supported then "-zstd" else ""

(* An uncompressed payload can be read whether or not this odoc would write
   one, so accept it too rather than rejecting a file we can perfectly well
   read. The converse isn't true, which is what the version distinguishes. *)
let readable_version version =
  version = magic_version || version = magic_version_uncompressed

(** Exceptions while saving are allowed to leak. *)
let save_ file f =
  let len = String.length magic_version in
  (* Sanity check, see similar check in load_ *)
  if len > 255 then
    failwith
      (Printf.sprintf
         "Magic version string %S is too long, must be <= 255 characters"
         magic_version);

  Fs.Directory.mkdir_p (Fs.File.dirname file);
  Io_utils.with_open_out_bin (Fs.File.to_string file) (fun oc ->
      output_string oc magic;
      output_binary_int oc len;
      output_string oc magic_version;
      f oc)

let save_unit file (root : Root.t) (t : t) =
  save_ file (fun oc ->
      output_value oc root;
      output_value oc t)

let save_page file ~warnings page =
  let dir = Fs.File.dirname file in
  let base = Fs.File.(to_string @@ basename file) in
  let file =
    if Astring.String.is_prefix ~affix:"page-" base then file
    else Fs.File.create ~directory:dir ~name:("page-" ^ base)
  in
  save_unit file page.Lang.Page.root { content = Page_content page; warnings }

let save_impl file ~warnings impl =
  let dir = Fs.File.dirname file in
  let base = Fs.File.(to_string @@ basename file) in
  let file =
    if Astring.String.is_prefix ~affix:"impl-" base then file
    else Fs.File.create ~directory:dir ~name:("impl-" ^ base)
  in
  save_unit file impl.Lang.Implementation.root
    { content = Impl_content impl; warnings }

let save_asset file ~warnings asset =
  let dir = Fs.File.dirname file in
  let base = Fs.File.(to_string @@ basename file) in
  let file =
    if Astring.String.is_prefix ~affix:"asset-" base then file
    else Fs.File.create ~directory:dir ~name:("asset-" ^ base)
  in
  let t = { content = Asset_content asset; warnings } in
  save_unit file asset.root t

let save_unit file ~warnings m =
  save_unit file m.Lang.Compilation_unit.root
    { content = Unit_content m; warnings }

let load_ file f =
  let file = Fs.File.to_string file in

  let check_exists () =
    if Sys.file_exists file then Ok ()
    else Error (`Msg (Printf.sprintf "File %s does not exist" file))
  in

  let check_magic ic =
    let actual_magic = really_input_string ic (String.length magic) in
    if actual_magic = magic then Ok ()
    else
      Error
        (`Msg
           (Printf.sprintf "%s has invalid magic %S, expected %S\n%!" file
              actual_magic magic))
  in
  let version_length ic () =
    let len = input_binary_int ic in
    if len > 0 && len <= 255 then Ok len
    else Error (`Msg (Printf.sprintf "%s has invalid version length" file))
  in
  let check_version ic len =
    let actual_magic = really_input_string ic len in
    if readable_version actual_magic then Ok ()
    else
      let msg =
        Printf.sprintf "%s has invalid version %S, expected %S\n%!" file
          actual_magic magic_version
      in
      Error (`Msg msg)
  in

  check_exists () >>= fun () ->
  Io_utils.with_open_in_bin file @@ fun ic ->
  try
    check_magic ic >>= version_length ic >>= check_version ic >>= fun () -> f ic
  with exn ->
    let msg =
      Printf.sprintf "Error while unmarshalling %S: %s\n%!" file
        (match exn with Failure s -> s | _ -> Printexc.to_string exn)
    in
    Error (`Msg msg)

let load file =
  load_ file (fun ic ->
      let _root = input_value ic in
      Ok (input_value ic))

(** The root is saved separately in the files to support this function. *)
let load_root file =
  load_ file (fun ic ->
      let root = input_value ic in
      Ok root)

let save_index dst idx = save_ dst (fun oc -> output_value oc idx)

let load_index file = load_ file (fun ic -> Ok (input_value ic))

let save_sidebar dst idx = save_ dst (fun oc -> output_value oc idx)

let load_sidebar file = load_ file (fun ic -> Ok (input_value ic))