--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Tools/Cache_IO/cache_io.ML Tue Feb 16 15:25:36 2010 +0100
@@ -0,0 +1,121 @@
+(* Title: Tools/Cache_IO/cache_io.ML
+ Author: Sascha Boehme, TU Muenchen
+
+Cache for output of external processes.
+*)
+
+signature CACHE_IO =
+sig
+ val with_tmp_file: string -> (Path.T -> 'a) -> 'a
+ val run: (Path.T -> string) -> Path.T -> string list
+ val run': (Path.T -> Path.T -> string) -> Path.T -> string list * string list
+
+ type cache
+ val make: Path.T -> cache
+ val cache_path_of: cache -> Path.T
+ val cached: cache -> (Path.T -> string) -> Path.T -> string list
+ val cached': cache -> (Path.T -> Path.T -> string) -> Path.T ->
+ string list * string list
+end
+
+structure Cache_IO : CACHE_IO =
+struct
+
+fun with_tmp_file name f =
+ let
+ val path = File.tmp_path (Path.explode (name ^ serial_string ()))
+ val x = Exn.capture f path
+ val _ = try File.rm path
+ in Exn.release x end
+
+fun run' make_cmd in_path =
+ with_tmp_file "cache-io-" (fn out_path =>
+ let
+ val (out2, _) = bash_output (make_cmd in_path out_path)
+ val out1 = the_default [] (try (rev o File.fold_lines cons out_path) [])
+ in (out1, split_lines out2) end)
+
+fun run make_cmd = snd o run' (fn in_path => fn _ => make_cmd in_path)
+
+
+
+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 load cache_path =
+ let
+ fun err () = error ("Cache IO: corrupted cache file: " ^
+ File.shell_path cache_path)
+
+ fun int_of_string s =
+ (case read_int (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
+
+fun make path =
+ let val table = if File.exists path then load path else (1, Symtab.empty)
+ in Cache {path=path, table=Synchronized.var (Path.implode path) table} end
+
+
+fun get_hash_key path =
+ let
+ val arg = File.shell_path path
+ val (out, res) = bash_output (getenv "COMPUTE_HASH_KEY" ^ " " ^ arg)
+ in
+ if res = 0 then hd (split_lines out)
+ else error ("Cache IO: failed to generate hash key for file " ^ arg)
+ end
+
+fun load_cached_result cache_path (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)
+ in pairself rev (snd (File.fold_lines load cache_path (1, ([], [])))) end
+
+fun cached' (Cache {path=cache_path, table}) make_cmd in_path =
+ let val key = get_hash_key in_path
+ in
+ (case Symtab.lookup (snd (Synchronized.value table)) key of
+ SOME pos => load_cached_result cache_path pos
+ | NONE =>
+ let
+ val res as (out, err) = run' make_cmd in_path
+ val (l1, l2) = pairself length res
+ 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 res end)
+ end
+
+fun cached cache make_cmd =
+ snd o cached' cache (fn in_path => fn _ => make_cmd in_path)
+
+end
+end