Reimplement cue file parser using liq code

.pre-commit-config.yaml

@@ -41,7 +41,7 @@ repos:
     hooks:
       - id: codespell
         args: [-w, --ignore-words=.codespellignore]
-        exclude: ^doc/orig/fosdem2020
+        exclude: ^(doc/orig/fosdem2020|tests/language/cue_test.liq)
 
   - repo: local
     hooks:

CHANGES.md

@@ -18,6 +18,9 @@ Changed:
 
 - Make alsa I/O work with buffer size different than
   liquidsoap internal frame (#4236)
+- Reimplemented CUE file parser in native liquidsoap script,
+  added support for multiple files and EAC non-compliant extension
+  (#1373, #4330)
 - Make `"song"` metadata mapping to `"title"` metadata in
   `input.harbor` disabled when either `"artist"` or `"title"`
   is also passed. Add a configuration key to disable this mechanism.

src/core/builtins/builtins_resolvers.ml

@@ -106,6 +106,22 @@ let _ =
       if reentrant then reentrant_decoders := format :: !reentrant_decoders;
       Lang.unit)
 
+let _ =
+  Lang.add_builtin ~base:Builtins_sys.playlist_parse "get_file"
+    ~category:`Liquidsoap ~descr:"Resolve a uri relative to a given pwd."
+    [
+      ( "pwd",
+        Lang.nullable_t Lang.string_t,
+        Some Lang.null,
+        Some "Current directory to use for relative file path." );
+      ("", Lang.string_t, None, Some "URI");
+    ]
+    Lang.string_t
+    (fun p ->
+      let pwd = Lang.to_valued_option Lang.to_string (List.assoc "pwd" p) in
+      let uri = Lang.to_string (List.assoc "" p) in
+      Lang.string (Playlist_parser.get_file ?pwd uri))
+
 let add_playlist_parser ~format name (parser : Playlist_parser.parser) =
   let return_t = Lang.list_t (Lang.product_t Lang.metadata_t Lang.string_t) in
   Lang.add_builtin ~base:Builtins_sys.playlist_parse name ~category:`Liquidsoap

src/core/playlists/playlist_basic.ml

@@ -118,187 +118,7 @@ let parse_scpls ?pwd string =
   let urls = List.filter (fun s -> s <> "") urls in
   List.map (fun t -> ([], Playlist_parser.get_file ?pwd t)) urls
 
-type cue_track = {
-  number : int;
-  track_performer : string option;
-  track_title : string option;
-  indexes : (int, float) Hashtbl.t;
-}
-
-type cue_sheet = {
-  file : string;
-  performer : string option;
-  title : string option;
-  tracks : cue_track list;
-}
-
-let parse_optional parser f =
-  try parser (fun x -> f (Some x)) with _ -> f None
-
-let parse_maybe_escaped escaped non_escaped f =
-  try escaped f with _ -> non_escaped f
-
-let parse_file s f =
-  let ret =
-    try
-      parse_maybe_escaped (Scanf.sscanf s "FILE %S %s")
-        (Scanf.sscanf s "FILE %s %s") (fun x _ -> x)
-    with _ -> raise Not_found
-  in
-  f ret
-
-let parse_title s =
-  parse_optional
-    (parse_maybe_escaped
-       (Scanf.sscanf s "TITLE %S")
-       (Scanf.sscanf s "TITLE %s"))
-
-let parse_performer s =
-  parse_optional
-    (parse_maybe_escaped
-       (Scanf.sscanf s "PERFORMER %S")
-       (Scanf.sscanf s "PERFORMER %s"))
-
-let parse_track s f =
-  try Scanf.sscanf s "TRACK %i %s" (fun i _ -> f i) with _ -> raise Not_found
-
-let parse_index s f =
-  try
-    Scanf.sscanf s "INDEX %i %i:%i:%i" (fun index min sec frames ->
-        let position =
-          (float_of_int min *. 60.)
-          +. float_of_int sec
-          +. (float_of_int frames /. 75.)
-        in
-        f index position)
-  with _ -> raise Not_found
-
-let find_file l =
-  let rec find cur rem =
-    match rem with
-      | x :: rem -> (
-          try parse_file x (fun title -> (title, cur, rem))
-          with Not_found -> find (x :: cur) rem)
-      | [] -> raise Not_found
-  in
-  let title, cur, rem = find [] l in
-  (List.rev cur @ rem, title)
-
-let parse_tracks index lines =
-  let rec parse tracks track rem =
-    match rem with
-      | [] -> List.rev (track :: tracks)
-      | x :: rem -> (
-          try
-            parse_track x (fun index ->
-                let tracks = track :: tracks in
-                let track =
-                  {
-                    number = index;
-                    track_title = None;
-                    track_performer = None;
-                    indexes = Hashtbl.create 1;
-                  }
-                in
-                parse tracks track rem)
-          with _ ->
-            let track =
-              parse_title x (fun title ->
-                  if title <> None then { track with track_title = title }
-                  else track)
-            in
-            let track =
-              parse_performer x (fun performer ->
-                  if performer <> None then
-                    { track with track_performer = performer }
-                  else track)
-            in
-            begin
-              try parse_index x (Hashtbl.replace track.indexes)
-              with Not_found -> ()
-            end;
-            parse tracks track rem)
-  in
-  let track =
-    {
-      number = index;
-      track_title = None;
-      track_performer = None;
-      indexes = Hashtbl.create 1;
-    }
-  in
-  parse [] track lines
-
-let parse_cue ?pwd string =
-  let strings = split_lines string in
-  let strings =
-    List.map
-      (fun string ->
-        Re.Pcre.substitute ~rex:(Re.Pcre.regexp "^\\s+")
-          ~subst:(fun _ -> "")
-          string)
-      strings
-  in
-  let strings = List.filter (fun s -> s <> "") strings in
-  let strings, file = find_file strings in
-  let rec parse sheet rem =
-    match rem with
-      | [] -> sheet
-      | x :: rem -> (
-          let sheet =
-            parse_title x (fun title ->
-                if title <> None then { sheet with title } else sheet)
-          in
-          let sheet =
-            parse_performer x (fun performer ->
-                if performer <> None then { sheet with performer } else sheet)
-          in
-          try
-            parse_track x (fun index ->
-                { sheet with tracks = parse_tracks index rem })
-          with Not_found -> parse sheet rem)
-  in
-  let sheet = { file; performer = None; title = None; tracks = [] } in
-  let sheet = parse sheet strings in
-  let export_track ?cue_out track =
-    let metadata = [("track", string_of_int track.number)] in
-    let maybe label value metadata =
-      match value with
-        | Some value -> (label, value) :: metadata
-        | None -> metadata
-    in
-    let metadata = maybe "artist" sheet.performer metadata in
-    let metadata = maybe "album" sheet.title metadata in
-    let metadata = maybe "artist" track.track_performer metadata in
-    let metadata = maybe "title" track.track_title metadata in
-    let metadata =
-      maybe Playlist_parser.conf_cue_in_metadata#get
-        (try Some (string_of_float (Hashtbl.find track.indexes 1))
-         with _ -> None)
-        metadata
-    in
-    ( maybe Playlist_parser.conf_cue_out_metadata#get cue_out metadata,
-      Playlist_parser.get_file ?pwd sheet.file )
-  in
-  let rec export_tracks cur tracks =
-    match tracks with
-      | [] ->
-          assert (cur == []);
-          []
-      | [track] -> List.rev (export_track track :: cur)
-      | track :: track' :: tracks ->
-          let cue_out =
-            try Some (string_of_float (Hashtbl.find track'.indexes 0))
-            with _ -> (
-              try Some (string_of_float (Hashtbl.find track'.indexes 1))
-              with _ -> None)
-          in
-          export_tracks (export_track ?cue_out track :: cur) (track' :: tracks)
-  in
-  export_tracks [] sheet.tracks
-
 let _ =
   Builtins_resolvers.add_playlist_parser ~format:"SCPLS" "scpls" parse_scpls
 
-let _ = Builtins_resolvers.add_playlist_parser ~format:"CUE" "cue" parse_cue
 let _ = Builtins_resolvers.add_playlist_parser ~format:"M3U" "m3u" parse_mpegurl