Fix #348540; also do some related additional changes

  * Closes: #348540 (grep-dctrl: stores whole input in memory)
    Reported by Christoph Berg <myon@debian.org>.
    - fsaf.c: Prefer reusing the current buffer instead of enlarging it,
      when not using mmap(2).
    - fsaf.h,fsaf.c: Fix invalidation for non-mmap buffers.
  * fsaf.h,fsaf.c: Make it possible to turn off mmapping.
  * fsaf.h,fsaf.c: Preallocate a 64KB buffer when not mmapping.
  * grep-dctrl.c,sort-dctrl.c,tbl-dctrl.c:
    Make mmap optional (defaults to no mmapping; new option --mmap).

1 files changed, 6 insertions, 0 deletions

diff --git a/sort-dctrl.c b/sort-dctrl.c
index b9556f6..5a4c8b1 100644
--- a/sort-dctrl.c
+++ b/sort-dctrl.c
@@ -27,6 +27,7 @@
 #include "sorter.h"
 
 #define OPT_SILENT 256
+#define OPT_MMAP 257
 
 const char * argp_program_version = "sort-dctrl (dctrl-tools) " VERSION;
 const char * argp_program_bug_address = MAINTAINER;
@@ -35,6 +36,7 @@ static struct argp_option options[] = {
 	{ "copying",	       'C', 0,		    0, N_("Print out the copyright license.") },
 	{ "errorlevel",	       'l', N_("LEVEL"),    0, N_("Set debugging level to LEVEL.") },
 	{ "key-spec",          'k', N_("KEYSPEC"),  0, N_("Specify sort keys.") },
+	{ "mmap",               OPT_MMAP, 0,        0, N_("Attempt mmapping input files") },
 	{ 0 }
 };
 
@@ -101,6 +103,10 @@ static error_t parse_opt (int key, char * arg, struct argp_state * state)
 		debug_message("parse_opt: l", 0);
 	}
 		break;
+	case OPT_MMAP:
+		debug_message("parse_opt: mmap", 0);
+		fsaf_mmap = 1;
+		break;
 	case ARGP_KEY_ARG:
 		debug_message("parse_opt: argument", 0);
 		{