Add a marshalled input/output format for search indexes

Signed-off-by: Paul-Elliot <[email protected]>

src/model/paths.ml

@@ -636,6 +636,10 @@ module Identifier = struct
       mk_parent LocalName.to_string "sli" (fun (p, n) ->
           `SourceLocationInternal (p, n))
   end
+
+  module Hashtbl = struct
+    module Any = Hashtbl.Make (Any)
+  end
 end
 
 module Path = struct

src/model/paths.mli

@@ -236,6 +236,10 @@ module Identifier : sig
     end
   end
 
+  module Hashtbl : sig
+    module Any : Hashtbl.S with type key = Any.t
+  end
+
   module Mk : sig
     open Names
 

src/odoc/bin/main.ml

@@ -403,46 +403,56 @@ module Source_tree = struct
 end
 
 module Indexing = struct
-  let output_file ~dst =
-    match dst with
-    | Some file -> Fs.File.of_string file
-    | None -> Fs.File.of_string "index.json"
-
-  let index dst warnings_options inputs_in_file inputs =
-    let output = output_file ~dst in
+  let output_file ~dst marshall =
+    match (dst, marshall) with
+    | Some file, _ -> Fs.File.of_string file
+    | None, `JSON -> Fs.File.of_string "index.json"
+    | None, `Marshall -> Fs.File.of_string "index-index.odoc"
+
+  let index dst marshall warnings_options inputs_in_file inputs =
+    let marshall = if marshall then `Marshall else `JSON in
+    let output = output_file ~dst marshall in
     match (inputs_in_file, inputs) with
     | [], [] ->
         Result.Error
           (`Msg
             "At least one of --file-list or an .odocl file must be passed to \
              odoc compile-index")
-    | _ -> Indexing.compile ~output ~warnings_options inputs_in_file inputs
+    | _ ->
+        Indexing.compile marshall ~output ~warnings_options inputs_in_file
+          inputs
 
   let cmd =
     let dst =
       let doc =
         "Output file path. Non-existing intermediate directories are created. \
-         Defaults to index.json"
+         Defaults to index.json, or index-index.odoc if --marshall is passed \
+         (in which case, the $(i,index-) prefix is mandatory)."
       in
       Arg.(
         value & opt (some string) None & info ~docs ~docv:"PATH" ~doc [ "o" ])
     in
     let inputs_in_file =
       let doc =
-        "Input text file containing a line-separated list of paths to .odocl \
-         files to index."
+        "Input text file containing a line-separated list of paths to \
+         .odocl/.json files to index."
       in
       Arg.(
         value & opt_all convert_fpath []
         & info ~doc ~docv:"FILE" [ "file-list" ])
     in
+    let marshall =
+      let doc = "whether to output a json file, or an .odoc file" in
+      Arg.(value & flag & info ~doc [ "marshall" ])
+    in
     let inputs =
-      let doc = ".odocl file to index" in
+      let doc = ".odocl/.json file to index" in
       Arg.(value & pos_all convert_fpath [] & info ~doc ~docv:"FILE" [])
     in
     Term.(
       const handle_error
-      $ (const index $ dst $ warnings_options $ inputs_in_file $ inputs))
+      $ (const index $ dst $ marshall $ warnings_options $ inputs_in_file
+       $ inputs))
 
   let info ~docs =
     let doc =

src/odoc/indexing.ml

@@ -3,18 +3,26 @@ open Odoc_json_index
 open Or_error
 open Odoc_model
 
-let handle_file file ~unit ~page =
-  Odoc_file.load file >>= fun unit' ->
-  match unit' with
-  | { Odoc_file.content = Unit_content unit'; _ } when unit'.hidden ->
-      Error (`Msg "Hidden units are ignored when generating an index")
-  | { Odoc_file.content = Unit_content unit'; _ } (* when not unit'.hidden *) ->
-      Ok (unit unit')
-  | { Odoc_file.content = Page_content page'; _ } -> Ok (page page')
-  | _ ->
-      Error
-        (`Msg
-          "Only pages and unit are allowed as input when generating an index")
+module H = Odoc_model.Paths.Identifier.Hashtbl.Any
+
+let handle_file file ~unit ~page ~occ =
+  match Fpath.basename file with
+  | s when String.is_prefix ~affix:"index-" s ->
+      Odoc_file.load_index file >>= fun index -> Ok (occ index)
+  | _ -> (
+      Odoc_file.load file >>= fun unit' ->
+      match unit' with
+      | { Odoc_file.content = Unit_content unit'; _ } when unit'.hidden ->
+          Error (`Msg "Hidden units are ignored when generating an index")
+      | { Odoc_file.content = Unit_content unit'; _ }
+      (* when not unit'.hidden *) ->
+          Ok (unit unit')
+      | { Odoc_file.content = Page_content page'; _ } -> Ok (page page')
+      | _ ->
+          Error
+            (`Msg
+              "Only pages and unit are allowed as input when generating an \
+               index"))
 
 let parse_input_file input =
   let is_sep = function '\n' | '\r' -> true | _ -> false in
@@ -32,7 +40,7 @@ let parse_input_files input =
     (Ok []) input
   >>= fun files -> Ok (List.concat files)
 
-let compile ~output ~warnings_options inputs_in_file inputs =
+let compile_to_json ~output ~warnings_options inputs_in_file inputs =
   parse_input_files inputs_in_file >>= fun files ->
   let files = List.rev_append inputs files in
   let output_channel =
@@ -53,6 +61,7 @@ let compile ~output ~warnings_options inputs_in_file inputs =
           handle_file
             ~unit:(print Json_search.unit acc)
             ~page:(print Json_search.page acc)
+            ~occ:(print Json_search.index acc)
             file
         with
         | Ok acc -> acc
@@ -66,3 +75,56 @@ let compile ~output ~warnings_options inputs_in_file inputs =
   result |> Error.handle_warnings ~warnings_options >>= fun (_ : bool) ->
   Format.fprintf output "]";
   Ok ()
+
+let compile_to_marshall ~output ~warnings_options inputs_in_file inputs =
+  parse_input_files inputs_in_file >>= fun files ->
+  let files = List.rev_append inputs files in
+  let final_index = H.create 10 in
+  let unit u =
+    Odoc_model.Fold.unit
+      ~f:(fun () item ->
+        let entries =
+          Odoc_search.Entry.entries_of_item
+            (* (u.Odoc_model.Lang.Compilation_unit.id *)
+            (*   :> Odoc_model.Paths.Identifier.t) *)
+            item
+        in
+        List.iter
+          (fun entry -> H.add final_index entry.Odoc_search.Entry.id entry)
+          entries)
+      () u
+  in
+  let page p =
+    Odoc_model.Fold.page
+      ~f:(fun () item ->
+        let entries =
+          Odoc_search.Entry.entries_of_item
+            (* (p.Odoc_model.Lang.Page.name :> Odoc_model.Paths.Identifier.t) *)
+            item
+        in
+        List.iter
+          (fun entry -> H.add final_index entry.Odoc_search.Entry.id entry)
+          entries)
+      () p
+  in
+  let index i = H.iter (H.add final_index) i in
+  let index () =
+    List.fold_left
+      (fun acc file ->
+        match handle_file ~unit ~page ~occ:index file with
+        | Ok acc -> acc
+        | Error (`Msg m) ->
+            Error.raise_warning ~non_fatal:true
+              (Error.filename_only "%s" m (Fs.File.to_string file));
+            acc)
+      () files
+  in
+  let result = Error.catch_warnings index in
+  result |> Error.handle_warnings ~warnings_options >>= fun () ->
+  Ok (Odoc_file.save_index output final_index)
+
+let compile out_format ~output ~warnings_options inputs_in_file inputs =
+  match out_format with
+  | `JSON -> compile_to_json ~output ~warnings_options inputs_in_file inputs
+  | `Marshall ->
+      compile_to_marshall ~output ~warnings_options inputs_in_file inputs

src/odoc/indexing.mli

@@ -4,11 +4,13 @@ val handle_file :
   Fpath.t ->
   unit:(Odoc_model.Lang.Compilation_unit.t -> 'a) ->
   page:(Odoc_model.Lang.Page.t -> 'a) ->
+  occ:(Odoc_search.Entry.t Odoc_model.Paths.Identifier.Hashtbl.Any.t -> 'a) ->
   ('a, [> msg ]) result
 (** This function is exposed for custom indexers that uses [odoc] as a library
     to generate their search index *)
 
 val compile :
+  [ `JSON | `Marshall ] ->
   output:Fs.file ->
   warnings_options:Odoc_model.Error.warnings_options ->
   Fs.file list ->

src/odoc/odoc_file.ml

@@ -30,14 +30,18 @@ type t = { content : content; warnings : Odoc_model.Error.t list }
 let magic = "odoc-%%VERSION%%"
 
 (** Exceptions while saving are allowed to leak. *)
-let save_unit file (root : Root.t) (t : t) =
+let save_ file f =
   Fs.Directory.mkdir_p (Fs.File.dirname file);
   let oc = open_out_bin (Fs.File.to_string file) in
   output_string oc magic;
-  Marshal.to_channel oc root [];
-  Marshal.to_channel oc t [];
+  f oc;
   close_out oc
 
+let save_unit file (root : Root.t) (t : t) =
+  save_ file (fun oc ->
+      Marshal.to_channel oc root [];
+      Marshal.to_channel oc t [])
+
 let save_page file ~warnings page =
   let dir = Fs.File.dirname file in
   let base = Fs.File.(to_string @@ basename file) in
@@ -70,9 +74,7 @@ let load_ file f =
   let res =
     try
       let actual_magic = really_input_string ic (String.length magic) in
-      if actual_magic = magic then
-        let root = Marshal.from_channel ic in
-        f ic root
+      if actual_magic = magic then f ic
       else
         let msg =
           Printf.sprintf "%s: invalid magic number %S, expected %S\n%!" file
@@ -89,7 +91,17 @@ let load_ file f =
   close_in ic;
   res
 
-let load file = load_ file (fun ic _ -> Ok (Marshal.from_channel ic))
+let load file =
+  load_ file (fun ic ->
+      let _root = Marshal.from_channel ic in
+      Ok (Marshal.from_channel ic))
 
 (** The root is saved separately in the files to support this function. *)
-let load_root file = load_ file (fun _ root -> Ok root)
+let load_root file =
+  load_ file (fun ic ->
+      let root = Marshal.from_channel ic in
+      Ok root)
+
+let save_index dst idx = save_ dst (fun oc -> Marshal.to_channel oc idx [])
+
+let load_index file = load_ file (fun ic -> Ok (Marshal.from_channel ic))

src/odoc/odoc_file.mli

@@ -49,3 +49,11 @@ val load : Fs.File.t -> (t, [> msg ]) result
 
 val load_root : Fs.File.t -> (Root.t, [> msg ]) result
 (** Only load the root. Faster than {!load}, used for looking up imports. *)
+
+val save_index :
+  Fs.File.t -> Odoc_search.Entry.t Paths.Identifier.Hashtbl.Any.t -> unit
+
+val load_index :
+  Fs.File.t ->
+  (Odoc_search.Entry.t Paths.Identifier.Hashtbl.Any.t, [> msg ]) result
+(** Load an [.odoc] file. *)

src/search/json_index/json_search.ml

@@ -214,3 +214,13 @@ let page ppf (page : Odoc_model.Lang.Page.t) =
   in
   let _first = Odoc_model.Fold.page ~f true page in
   ()
+
+let index ppf (index : Entry.t Odoc_model.Paths.Identifier.Hashtbl.Any.t) =
+  let _first =
+    Odoc_model.Paths.Identifier.Hashtbl.Any.fold
+      (fun _id entry first ->
+        let entry = (entry, Html.of_entry entry) in
+        output_json ppf first [ entry ])
+      index true
+  in
+  ()

src/search/json_index/json_search.mli

@@ -2,3 +2,7 @@
 
 val unit : Format.formatter -> Odoc_model.Lang.Compilation_unit.t -> unit
 val page : Format.formatter -> Odoc_model.Lang.Page.t -> unit
+val index :
+  Format.formatter ->
+  Odoc_search.Entry.t Odoc_model.Paths.Identifier.Hashtbl.Any.t ->
+  unit

test/search/html_search.t/run.t

@@ -48,14 +48,21 @@ we will generate.
   $ odoc html-generate --search-uri fuse.js.js --search-uri index.js -o html page-page.odocl
   $ odoc support-files -o html
 
-We now focus on how to generate the index.js file. There are mainly two ways: by
-using odoc as a library, or by using the the `compile-index` command. This
-command generates a json index containing all .odocl given as input, to be
-consumed later by a search engine. If -o is not provided, the file is saved as
-index.json.
-Odocl files can be given either in a list (using --file-list,
-passing a file with the list of line-separated files), or by passing directly
-the name of the files.
+We now focus on how to generate the index.js file.
+
+For this, we compute an index of all the values contained in a given list of
+odoc files, using the `compile-index` command.
+
+This command generates has two output format: a json output for consumption by
+external search engine, and an `odoc` specific extension.  The odoc file is
+meant to be consumed either by search engine written in OCaml, which would
+depend on `odoc` as a library, or by `odoc` itself to build a global index
+incrementally: the `compile-index` command can take indexes as input!
+
+If -o is not provided, the file is saved as index.json, or index-index.odoc if
+the --marshall flag is passed.  Odocl files can be given either in a list (using
+--file-list, passing a file with the list of line-separated files), or by
+passing directly the name of the files.
 
   $ printf "main.odocl\npage-page.odocl\nj.odocl\n" > index_map
   $ odoc compile-index -o index1.json --file-list index_map
@@ -74,7 +81,48 @@ Let's check that the previous commands are indeed independent:
   $ diff index.json index1.json
   $ diff index.json index2.json
 
-The index file contains a json array, each element of the array corresponding to
+Let's now test the --marshall flag.
+We compare:
+- the result of outputing as a marshalled file, and then use that to output a json file.
+- Directly outputing a json file
+
+  $ odoc compile-index -o index-main.odoc --marshall main.odocl
+  $ odoc compile-index -o main.json index-main.odoc
+  $ cat main.json | jq sort | jq '.[]' -c | sort > main1.json
+
+  $ odoc compile-index -o main.json main.odocl
+  $ cat main.json | jq sort | jq '.[]' -c | sort > main2.json
+
+  $ diff main1.json main2.json
+
+  $ odoc compile-index -o index-j.odoc --marshall j.odocl
+  $ odoc compile-index -o j.json index-j.odoc
+  $ cat j.json | jq sort | jq '.[]' -c | sort > j1.json
+
+  $ odoc compile-index -o j.json j.odocl
+  $ cat j.json | jq sort | jq '.[]' -c | sort > j2.json
+
+  $ diff j1.json j2.json
+
+  $ odoc compile-index -o index-page.odoc --marshall page-page.odocl
+  $ odoc compile-index -o page.json index-page.odoc
+  $ cat page.json | jq sort | jq '.[]' -c | sort > page1.json
+
+  $ odoc compile-index -o page.json page-page.odocl
+  $ cat page.json | jq sort | jq '.[]' -c | sort > page2.json
+
+  $ diff page1.json page2.json
+
+Now, we compare the combination of the three marshalled files (index-main.odoc,
+index-page.odoc, index-j.odoc).
+
+  $ odoc compile-index -o all.json index-page.odoc index-j.odoc index-main.odoc
+  $ cat all.json | jq sort | jq '.[]' -c | sort > all1.json
+
+  $ cat index.json | jq sort | jq '.[]' -c | sort > all2.json
+  $ diff all1.json all2.json
+
+The json index file contains a json array, each element of the array corresponding to
 a search entry.
 An index entry contains:
 - an ID,