(* Title: Tools/cache_io.ML
Author: Sascha Boehme, TU Muenchen
Cache for output of external processes.
*)
signature CACHE_IO =
sig
(*IO wrapper*)
type result = {
output: string list,
redirected_output: string list,
return_code: int}
val raw_run: (Path.T -> Path.T -> string) -> string -> Path.T -> Path.T -> result
val run: (Path.T -> Path.T -> string) -> string -> result
(*cache*)
type cache
val unsynchronized_init: Path.T -> cache
val cache_path_of: cache -> Path.T
val lookup: cache -> string -> result option * string
val run_and_cache: cache -> string -> (Path.T -> Path.T -> string) -> string -> result
val run_cached: cache -> (Path.T -> Path.T -> string) -> string -> result
end
structure Cache_IO : CACHE_IO =
struct
(* IO wrapper *)
val cache_io_prefix = "cache-io-"
type result = {
output: string list,
redirected_output: string list,
return_code: int}
fun raw_run make_cmd str in_path out_path =
let
val _ = File.write in_path str
val (out2, rc) = Isabelle_System.bash_output (make_cmd in_path out_path)
val out1 = the_default [] (try (rev o File.fold_lines cons out_path) [])
in {output = split_lines out2, redirected_output = out1, return_code = rc} end
fun run make_cmd str =
Isabelle_System.with_tmp_file cache_io_prefix "" (fn in_path =>
Isabelle_System.with_tmp_file cache_io_prefix "" (fn out_path =>
raw_run make_cmd str in_path out_path))
(* cache *)
abstype cache = Cache of {
path: Path.T,
table: (int * (int * int * int) Symtab.table) Synchronized.var }
with
fun cache_path_of (Cache {path, ...}) = path
fun unsynchronized_init cache_path =
let
val table =
if File.exists cache_path then
let
fun err () = error ("Cache IO: corrupted cache file: " ^ File.shell_path cache_path)
fun int_of_string s =
(case read_int (raw_explode s) of
(i, []) => i
| _ => err ())
fun split line =
(case space_explode " " line of
[key, len1, len2] => (key, int_of_string len1, int_of_string len2)
| _ => err ())
fun parse line ((i, l), tab) =
if i = l
then
let val (key, l1, l2) = split line
in ((i+1, l+l1+l2+1), Symtab.update (key, (i+1, l1, l2)) tab) end
else ((i+1, l), tab)
in apfst fst (File.fold_lines parse cache_path ((1, 1), Symtab.empty)) end
else (1, Symtab.empty)
in Cache {path = cache_path, table = Synchronized.var "Cache_IO" table} end
fun lookup (Cache {path = cache_path, table}) str =
let val key = SHA1.rep (SHA1.digest str)
in
Synchronized.change_result table (fn tab =>
(case Symtab.lookup (snd tab) key of
NONE => ((NONE, key), tab)
| SOME (p, len1, len2) =>
let
fun load line (i, xsp) =
if i < p then (i+1, xsp)
else if i < p + len1 then (i+1, apfst (cons line) xsp)
else if i < p + len2 then (i+1, apsnd (cons line) xsp)
else (i, xsp)
val (out, err) =
apply2 rev (snd (File.fold_lines load cache_path (1, ([], []))))
in ((SOME {output = err, redirected_output = out, return_code = 0}, key), tab) end))
end
fun run_and_cache (Cache {path = cache_path, table}) key make_cmd str =
let
val {output = err, redirected_output=out, return_code} = run make_cmd str
val (l1, l2) = apply2 length (out, err)
val header = key ^ " " ^ string_of_int l1 ^ " " ^ string_of_int l2
val lines = map (suffix "\n") (header :: out @ err)
val _ = Synchronized.change table (fn (p, tab) =>
if Symtab.defined tab key then (p, tab)
else
let val _ = File.append_list cache_path lines
in (p+l1+l2+1, Symtab.update (key, (p+1, l1, l2)) tab) end)
in {output = err, redirected_output = out, return_code = return_code} end
fun run_cached cache make_cmd str =
(case lookup cache str of
(NONE, key) => run_and_cache cache key make_cmd str
| (SOME output, _) => output)
end
end