infrastructure for safe marshal-based IPC

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@12879 85f007b7-540e-0410-9357-904b9bb8a0f7

1 files changed, 39 insertions, 0 deletions

diff --git a/lib/safe_marshal.ml b/lib/safe_marshal.ml
new file mode 100644
index 0000000000..88101b5d2f
--- /dev/null
+++ b/lib/safe_marshal.ml
@@ -0,0 +1,39 @@
+(************************************************************************)
+(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
+(* <O___,, * CNRS-Ecole Polytechnique-INRIA Futurs-Universite Paris Sud *)
+(*   \VV/  **************************************************************)
+(*    //   *      This file is distributed under the terms of the       *)
+(*         *       GNU Lesser General Public License Version 2.1        *)
+(************************************************************************)
+
+(* $Id$ *)
+
+let hobcnv = Array.init 256 (fun i -> Printf.sprintf "%.2x" i)
+let bohcnv = Array.init 256 (fun i -> i -
+                                      (if 0x30 <= i then 0x30 else 0) -
+                                      (if 0x41 <= i then 0x7 else 0) -
+                                      (if 0x61 <= i then 0x20 else 0))
+
+let hex_of_bin ch = hobcnv.(int_of_char ch)
+let bin_of_hex s = bohcnv.(char_of_int s[0]) * 16 + bohcnv.(char_of_int s[1])
+
+let send cout expr =
+  let mshl_expr = Marshal.to_string expr [] in
+  let payload = Buffer.create (String.length mshl_expr * 2) in
+  String.iter (fun c -> Buffer.add_string payload (hex_of_bin c)) mshl_expr;
+  Buffer.add_char payload '\n';
+  output_string cout (Buffer.contents payload);
+  flush cout
+
+
+let receive cin =
+  let payload = input_line cin in
+  let mshl_expr_len = String.length payload / 2 in
+  let mshl_expr = Buffer.create mshl_expr_len in
+  let buf = String.create 2 in
+  for i = 0 to mshl_expr_len - 1 do
+    String.blit payload (2*i) buf 0 2;
+    Buffer.add_char mshl_expr (bin_of_hex buf)
+  done;
+  Marshal.from_string (Buffer.contents mshl_expr) 0
+