[groff] 07/47: [libbib, libgroff, indxbib]: Slightly refactor.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit 4c7a3396375b76c0d45483ba1cf3d22508a7d2fd
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Wed Jan 5 09:58:54 2022 +1100

    [libbib, libgroff, indxbib]: Slightly refactor.
    
    Also, it's silly to test even numbers > 2 for primality.  Stop.
    
    * src/include/lib.h: Include `stdbool.h` since this header file is used
      for both C and C++ code.
    
    * src/include/lib.h (is_prime):
    * src/libs/libgroff/prime.cpp (is_prime): Boolify.  Return Boolean
      instead of integer literals and demote return type to `bool`.  Include
      `assert.h` and add assertion to reject mathematically offensive input.
    
    * src/libs/libbib/index.cpp (index_search_item::read_common_words_file):
      Test only odd numbers for primality.
    * src/utils/indxbib/indxbib.cpp (main): Same.  Since the number comes
      from user input, make it (a potential hash table size) odd first.
    
    Also add editor aid comments.
---
 ChangeLog                     | 22 ++++++++++++++++++++++
 src/include/lib.h             |  4 +++-
 src/libs/libbib/index.cpp     |  2 +-
 src/libs/libgroff/prime.cpp   | 22 +++++++++++++++-------
 src/utils/indxbib/indxbib.cpp | 22 +++++++++++++++++-----
 5 files changed, 58 insertions(+), 14 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 82b5aae6..6cfdb898 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,25 @@
+2022-01-05  G. Branden Robinson <g.branden.robinson@gmail.com>
+
+       [libbib, libgroff, indxbib]: Slightly refactor.
+
+       Also, it's silly to test even numbers > 2 for primality.  Stop.
+
+       * src/include/lib.h: Include `stdbool.h` since this header file
+       is used for both C and C++ code.
+
+       * src/include/lib.h (is_prime):
+       * src/libs/libgroff/prime.cpp (is_prime): Boolify.  Return
+       Boolean instead of integer literals and demote return type to
+       `bool`.  Include `assert.h` and add assertion to reject
+       mathematically offensive input.
+
+       * src/libs/libbib/index.cpp
+       (index_search_item::read_common_words_file): Test only odd
+       numbers for primality.
+       * src/utils/indxbib/indxbib.cpp (main): Same.  Since the number
+       comes from user input, make it (a potential hash table size) odd
+       first.
+
 2022-01-04  G. Branden Robinson <g.branden.robinson@gmail.com>
 
        [man]: Internationalize and localize.
diff --git a/src/include/lib.h b/src/include/lib.h
index a9ca8b48..ae43cee3 100644
--- a/src/include/lib.h
+++ b/src/include/lib.h
@@ -53,8 +53,10 @@ extern "C" {
 #define getlocale(category) ((void)(category), (char *)"C")
 #endif /* !HAVE_SETLOCALE */
 
+#include <stdbool.h>
+
 char *strsave(const char *s);
-int is_prime(unsigned);
+bool is_prime(unsigned);
 double groff_hypot(double, double);
 
 #include <stdio.h>
diff --git a/src/libs/libbib/index.cpp b/src/libs/libbib/index.cpp
index 5b716ee9..3fc9b941 100644
--- a/src/libs/libbib/index.cpp
+++ b/src/libs/libbib/index.cpp
@@ -615,7 +615,7 @@ void index_search_item::read_common_words_file()
   }
   common_words_table_size = 2*header.common + 1;
   while (!is_prime(common_words_table_size))
-    common_words_table_size++;
+    common_words_table_size += 2;
   common_words_table = new char *[common_words_table_size];
   for (int i = 0; i < common_words_table_size; i++)
     common_words_table[i] = 0;
diff --git a/src/libs/libgroff/prime.cpp b/src/libs/libgroff/prime.cpp
index 28485137..96001acc 100644
--- a/src/libs/libgroff/prime.cpp
+++ b/src/libs/libgroff/prime.cpp
@@ -18,29 +18,37 @@ internet at <http://www.gnu.org/licenses/gpl-2.0.txt>. */
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
+#include <assert.h>
 #include <math.h>
 
-int is_prime(unsigned n)
+bool is_prime(unsigned n)
 {
+  assert(n > 1);
   if (n <= 3)
-    return 1;
+    return true;
   if (!(n & 1))
-    return 0;
+    return false;
   if (n % 3 == 0)
-    return 0;
+    return false;
   unsigned lim = unsigned(sqrt((double)n));
   unsigned d = 5;
   for (;;) {
     if (d > lim)
       break;
     if (n % d == 0)
-      return 0;
+      return false;
     d += 2;
     if (d > lim)
       break;
     if (n % d == 0)
-      return 0;
+      return false;
     d += 4;
   }
-  return 1;
+  return true;
 }
+
+// Local Variables:
+// fill-column: 72
+// mode: C++
+// End:
+// vim: set cindent noexpandtab shiftwidth=2 textwidth=72:
diff --git a/src/utils/indxbib/indxbib.cpp b/src/utils/indxbib/indxbib.cpp
index b9e08021..1ccd2f0b 100644
--- a/src/utils/indxbib/indxbib.cpp
+++ b/src/utils/indxbib/indxbib.cpp
@@ -142,11 +142,17 @@ int main(int argc, char **argv)
       foption = optarg;
       break;
     case 'h':
-      check_integer_arg('h', optarg, 1, &hash_table_size);
-      if (!is_prime(hash_table_size)) {
-       while (!is_prime(++hash_table_size))
-         ;
-       warning("%1 not prime: using %2 instead", optarg, hash_table_size);
+      {
+       int requested_hash_table_size;
+       check_integer_arg('h', optarg, 1, &requested_hash_table_size);
+       hash_table_size = requested_hash_table_size;
+       if ((hash_table_size > 2) && (hash_table_size % 2) == 0)
+               hash_table_size++;
+       while (!is_prime(hash_table_size))
+         hash_table_size += 2;
+       if (hash_table_size != requested_hash_table_size)
+         warning("requested hash table size %1 is not prime: using %2"
+                 " instead", optarg, hash_table_size);
       }
       break;
     case 'i':
@@ -786,3 +792,9 @@ void cleanup()
 }
 
 }
+
+// Local Variables:
+// fill-column: 72
+// mode: C++
+// End:
+// vim: set cindent noexpandtab shiftwidth=2 textwidth=72: