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(*
* Copyright (c) 2009 - 2013 Monoidics ltd.
* Copyright (c) 2013 - present Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*)
open! Utils
module L = Logging
module F = Format
(** Generic serializer *)
type 'a serializer = (string -> 'a option) * (DB.filename -> 'a option) * (DB.filename -> 'a -> unit)
(** Serialization key, used to distinguish versions of serializers and avoid assert faults *)
type key = int
(** current key for tenv, procedure summary, cfg, error trace, call graph *)
let tenv_key, summary_key, cfg_key, trace_key, cg_key,
analysis_results_key, cluster_key, attributes_key, lint_issues_key =
425184201, 160179325, 1062389858, 221487792, 477305409,
799050016, 579094948, 972393003, 852343110
(** version of the binary files, to be incremented for each change *)
let version = 26
(** Retry the function while an exception filtered is thrown,
or until the timeout in seconds expires. *)
let retry_exception timeout catch_exn f x =
let init_time = Unix.gettimeofday () in
let expired () =
Unix.gettimeofday () -. init_time >= timeout in
let rec retry () =
try f x with
| e when catch_exn e && not (expired ()) ->
retry () in
retry ()
let create_serializer (key : key) : 'a serializer =
let match_data ((key': key), (version': int), (value: 'a)) source_msg =
if key <> key' then
begin
L.err "Wrong key in when loading data from %s@\n" source_msg;
None
end
else if version <> version' then
begin
L.err "Wrong version in when loading data from %s@\n" source_msg;
None
end
else Some value in
let from_string (str : string) : 'a option =
try
match_data (Marshal.from_string str 0) "string"
with Sys_error _ -> None in
let from_file (fname_ : DB.filename) : 'a option =
let fname = DB.filename_to_string fname_ in
match open_in_bin fname with
| exception Sys_error _ ->
None
| inc ->
let read () =
try
seek_in inc 0 ;
match_data (Marshal.from_channel inc) fname
with
| Sys_error _ -> None in
let timeout = 1.0 in
let catch_exn = function
| End_of_file -> true
| Failure _ -> true (* handle input_value: truncated object *)
| _ -> false in
(* Retry to read for 1 second in case of end of file, *)
(* which indicates that another process is writing the same file. *)
SymOp.try_finally
(fun () -> retry_exception timeout catch_exn read ())
(fun () -> close_in inc) in
let to_file (fname : DB.filename) (value : 'a) =
let fname_str = DB.filename_to_string fname in
(* support nonblocking reads and writes in parallel: *)
(* write to a tmp file and use rename which is atomic *)
let fname_tmp = Filename.temp_file
~temp_dir:(Filename.dirname fname_str) (Filename.basename fname_str) ".tmp" in
let outc = open_out_bin fname_tmp in
Marshal.to_channel outc (key, version, value) [];
close_out outc;
Unix.rename fname_tmp fname_str in
(from_string, from_file, to_file)
let from_string (serializer : 'a serializer) =
let (s, _, _) = serializer in s
let from_file (serializer : 'a serializer) =
let (_, s, _) = serializer in s
let to_file (serializer : 'a serializer) =
let (_, _, s) = serializer in s
(*
(** Generate random keys, to be used in an ocaml toplevel *)
let generate_keys () =
Random.self_init ();
let max_rand_int = 0x3FFFFFFF (* determined by Rand library *) in
let gen () = Random.int max_rand_int in
gen (), gen (), gen (), gen (), gen (), gen ()
*)