Add a check-zzuf-s-seed that tests whether all bits in a sequence have a

chance of being toggled.

.gitignore

@@ -27,6 +27,7 @@ src/zzuf
 src/zzcat
 test/zzero
 test/zznop
+test/zzone
 test/bug-div0
 test/bug-memory
 test/bug-overflow

test/Makefile.am

@@ -1,7 +1,7 @@
 
 EXTRA_DIST = $(TESTS) functions.inc file-00 file-ff file-random file-text
 
-noinst_PROGRAMS = zzero zznop bug-overflow bug-memory bug-div0
+noinst_PROGRAMS = zzero zznop zzone bug-overflow bug-memory bug-div0
 
 TESTS = check-zzuf-A-autoinc \
         check-zzuf-f-fuzzing \

test/check-zzuf-s-seed

@@ -0,0 +1,43 @@
+#!/bin/sh
+#
+#  check-zzuf-s-seed - zzuf seed efficiency statistic tests
+#  Copyright (c) 2008-2010 Sam Hocevar <sam@hocevar.net>
+#                All Rights Reserved
+#
+#  This program is free software. It comes without any warranty, to
+#  the extent permitted by applicable law. You can redistribute it
+#  and/or modify it under the terms of the Do What The Fuck You Want
+#  To Public License, Version 2, as published by Sam Hocevar. See
+#  http://sam.zoy.org/wtfpl/COPYING for more details.
+#
+
+. "$(dirname "$0")/functions.inc"
+
+start_test "zzuf -s test"
+
+for ratio in 1 0.1 0.01 0.001 0.0001; do
+  if test $ratio = 0.0001; then
+    bytes=1024
+  elif test $ratio = 0.001; then
+    bytes=8192
+  else
+    bytes=32768
+  fi
+  new_test "$bytes B of zeroes, ratio $ratio"
+  zeroes=$(expr $bytes '*' 4)
+  passes=10
+  while test $zeroes -gt 0 -a $passes -lt 200000; do
+    printf " doing $passes passes..."
+    zeroes=$($ZZUF -r $ratio -s $seed -A $ZZCAT -r $passes -x "fread(1,$bytes)" /dev/zero | $DIR/zzone $bytes $passes)
+    echo " $zeroes"
+    passes=$(expr '(' $passes '*' 7 + 3 ')' / 4)
+  done
+  if test $passes -lt 2000000; then
+      pass_test " ok"
+  else
+      pass_test " FAILED"
+  fi
+done
+
+stop_test
+

test/zzone.c

@@ -0,0 +1,85 @@
+/*
+ *  zzone - check that all bits are set to one after some time
+ *  Copyright (c) 2010 Sam Hocevar <sam@hocevar.net>
+ *                All Rights Reserved
+ *
+ *  This program is free software. It comes without any warranty, to
+ *  the extent permitted by applicable law. You can redistribute it
+ *  and/or modify it under the terms of the Do What The Fuck You Want
+ *  To Public License, Version 2, as published by Sam Hocevar. See
+ *  http://sam.zoy.org/wtfpl/COPYING for more details.
+ */
+
+#include "config.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#if defined HAVE_STDINT_H
+#   include <stdint.h>
+#elif defined HAVE_INTTYPES_H
+#   include <inttypes.h>
+#endif
+#include <string.h>
+
+int zero[16] =
+{
+    4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0
+};
+
+int main(int argc, char *argv[])
+{
+    uint8_t *buf, *tmp;
+    size_t i, last, size, count;
+
+    if (argc != 3)
+    {
+        fprintf(stderr, "usage: zzone <size> <count>\n");
+        return EXIT_FAILURE;
+    }
+
+    size = atoi(argv[1]);
+    count = atoi(argv[2]);
+    last = 0;
+
+    buf = malloc(size);
+    tmp = malloc(size);
+    if (!buf || !tmp)
+    {
+        fprintf(stderr, "zzone: cannot alloc memory\n");
+        return EXIT_FAILURE;
+    }
+    memset(buf, 0x00, size);
+
+    while (count--)
+    {
+        fread(tmp, size, 1, stdin);
+        for (i = last; i < size; i++)
+        {
+            buf[i] |= tmp[i];
+        }
+
+        while (last < size && buf[last] == 0xff)
+            last++;
+    }
+
+    free(buf);
+    free(tmp);
+
+    if (last != size)
+    {
+        size_t zeros = 0;
+        for (i = last; i < size; i++)
+        {
+            zeros += zero[buf[i] & 0xf];
+            zeros += zero[buf[i] >> 4];
+        }
+        printf("%li\n", (long)zeros);
+    }
+    else
+    {
+        puts("0");
+    }
+
+    return EXIT_SUCCESS;
+}
+