shuf: prefer xpalloc to xnrealloc

* src/shuf.c (RESERVOIR_LINES_INCREMENT): Remove.
All uses removed.
(read_input_reservoir_sampling, main):
Prefer idx_t to size_t for sizes related to xpalloc.
(read_input_reservoir_sampling): Prefer xpalloc to xnrealloc.

diff --git a/src/shuf.c b/src/shuf.c
index 63c26f31eee17f2602e8edada5783ceffc14e19b..0956abf53695f938d912678e5938535cf7ff679e 100644 (file)
--- a/src/shuf.c
+++ b/src/shuf.c
@@ -37,9 +37,6 @@
 
 #define AUTHORS proper_name ("Paul Eggert")
 
-/* For reservoir-sampling, allocate the reservoir lines in batches.  */
-enum { RESERVOIR_LINES_INCREMENT = 1024 };
-
 /* reservoir-sampling introduces CPU overhead for small inputs.
    So only enable it for inputs >= this limit.
    This limit was determined using these commands:
@@ -168,33 +165,30 @@ input_size (void)
 /* Read all lines and store up to K permuted lines in *OUT_RSRV.
    Return the number of lines read, up to a maximum of K.  */
 
-static size_t
-read_input_reservoir_sampling (FILE *in, char eolbyte, size_t k,
+static idx_t
+read_input_reservoir_sampling (FILE *in, char eolbyte, idx_t k,
                                struct randint_source *s,
                                struct linebuffer **out_rsrv)
 {
   randint n_lines = 0;
-  size_t n_alloc_lines = MIN (k, RESERVOIR_LINES_INCREMENT);
+  idx_t n_alloc_lines = 0;
   struct linebuffer *line = nullptr;
-  struct linebuffer *rsrv;
-
-  rsrv = xcalloc (n_alloc_lines, sizeof (struct linebuffer));
+  struct linebuffer *rsrv = nullptr;
 
   /* Fill the first K lines, directly into the reservoir.  */
-  while (n_lines < k
-         && (line =
-             readlinebuffer_delim (&rsrv[n_lines], in, eolbyte)) != nullptr)
+  for (n_lines = 0; n_lines < k; n_lines++)
     {
-      n_lines++;
-
-      /* Enlarge reservoir.  */
-      if (n_lines >= n_alloc_lines)
+      /* Enlarge reservoir if needed.  */
+      if (n_lines == n_alloc_lines)
         {
-          n_alloc_lines += RESERVOIR_LINES_INCREMENT;
-          rsrv = xnrealloc (rsrv, n_alloc_lines, sizeof (struct linebuffer));
-          memset (&rsrv[n_lines], 0,
-                  RESERVOIR_LINES_INCREMENT * sizeof (struct linebuffer));
+          idx_t old = n_alloc_lines;
+          rsrv = xpalloc (rsrv, &n_alloc_lines, 1, k, sizeof *rsrv);
+          memset (&rsrv[n_lines], 0, (n_alloc_lines - old) * sizeof *rsrv);
         }
+
+      line = readlinebuffer_delim (&rsrv[n_lines], in, eolbyte);
+      if (!line)
+        break;
     }
 
   /* last line wasn't null - so there may be more lines to read.  */
@@ -372,7 +366,7 @@ main (int argc, char **argv)
   bool input_range = false;
   size_t lo_input = SIZE_MAX;
   size_t hi_input = 0;
-  size_t head_lines = SIZE_MAX;
+  idx_t head_lines = MIN (IDX_MAX, SIZE_MAX);
   char const *outfile = nullptr;
   char *random_source = nullptr;
   char eolbyte = '\n';
@@ -523,7 +517,7 @@ main (int argc, char **argv)
 
       fadvise (stdin, FADVISE_SEQUENTIAL);
 
-      if (repeat || head_lines == SIZE_MAX
+      if (repeat || head_lines == MIN (IDX_MAX, SIZE_MAX)
           || input_size () <= RESERVOIR_MIN_INPUT)
         {
           n_lines = read_input (stdin, eolbyte, &input_lines);
@@ -538,7 +532,7 @@ main (int argc, char **argv)
 
   /* The adjusted head line count; can be less than HEAD_LINES if the
      input is small and if not repeating.  */
-  size_t ahead_lines = repeat || head_lines < n_lines ? head_lines : n_lines;
+  idx_t ahead_lines = repeat || head_lines < n_lines ? head_lines : n_lines;
 
   randint_source = randint_all_new (random_source,
                                     (use_reservoir_sampling || repeat