Rename compare_values, hash_values with "_short" suffix.

[pspp-builds.git] / src / data / value.c

diff --git a/src/data/value.c b/src/data/value.c
index 5e94b68c2ed81b5abf656e29edca9c4df9d26e2f..baaaed48d4c396a94312917a1becc7b7bee9f7c2 100644 (file)
--- a/src/data/value.c
+++ b/src/data/value.c
@@ -1,26 +1,26 @@
-/* PSPP - computes sample statistics.
+/* PSPP - a program for statistical analysis.
    Copyright (C) 1997-9, 2000 Free Software Foundation, Inc.
 
-   This program is free software; you can redistribute it and/or
-   modify it under the terms of the GNU General Public License as
-   published by the Free Software Foundation; either version 2 of the
-   License, or (at your option) any later version.
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
 
-   This program is distributed in the hope that it will be useful, but
-   WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   General Public License for more details.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
-   02110-1301, USA. */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>. */
 
 #include <config.h>
-#include "value.h"
+#include <data/value.h>
 
+#include <data/val-type.h>
 #include <libpspp/hash.h>
 #include <libpspp/str.h>
+#include "variable.h"
 
 #include "xalloc.h"
 
@@ -32,32 +32,49 @@ value_dup (const union value *val, int width)
   return xmemdup (val, MAX (width, sizeof *val));
 }
 
+
+/* Create a value of specified width.
+   The caller is responsible for freeing the returned value. */
+union value *
+value_create (int width)
+{
+  return xnmalloc (value_cnt_from_width (width), sizeof (union value));
+}
+
+
 /* Compares A and B, which both have the given WIDTH, and returns
    a strcmp()-type result.
    Only the short string portion of longer strings are
    compared. */
 int
-compare_values (const union value *a, const union value *b, int width) 
+compare_values_short (const void *a_, const void *b_, const void *var_) 
 {
-  return (width == 0
-          ? (a->f < b->f ? -1 : a->f > b->f)
-          : memcmp (a->s, b->s, MIN (MAX_SHORT_STRING, width)));
+  const union value *a = a_;
+  const union value *b = b_;
+  const struct variable *var = var_;
+  int width = var_get_width (var);
+  return value_compare_3way (a, b, MIN (width, MAX_SHORT_STRING));
 }
 
+
 /* Create a hash of V, which has the given WIDTH.
    Only the short string portion of a longer string is hashed. */
-unsigned 
-hash_value (const union value *v, int width)
+unsigned
+hash_value_short (const void *v_, const void *var_)
 {
+  const union value *v = v_;
+  const struct variable *var = var_;
+  int width = var_get_width (var);
   return (width == 0
           ? hsh_hash_double (v->f)
-          : hsh_hash_bytes (v->s, MIN (MAX_SHORT_STRING, width)));
+         : hsh_hash_bytes (v->s, width));
 }
 
+
 /* Copies SRC to DST, given that they both contain data of the
    given WIDTH. */
 void
-value_copy (union value *dst, const union value *src, int width) 
+value_copy (union value *dst, const union value *src, int width)
 {
   if (width == 0)
     dst->f = src->f;
@@ -68,10 +85,49 @@ value_copy (union value *dst, const union value *src, int width)
 /* Sets V to the system-missing value for data of the given
    WIDTH. */
 void
-value_set_missing (union value *v, int width) 
+value_set_missing (union value *v, int width)
 {
   if (width == 0)
     v->f = SYSMIS;
   else
-    memset (v->s, ' ', width); 
+    memset (v->s, ' ', width);
+}
+
+/* Tests whether VALUE may be resized from OLD_WIDTH to
+   NEW_WIDTH, using the following rules that match those for
+   resizing missing values and value labels.  First, OLD_WIDTH
+   and NEW_WIDTH must be both numeric or both string.  Second, if
+   NEW_WIDTH is less than OLD_WIDTH, then the bytes that would be
+   trimmed off the right end of VALUE must be all spaces. */
+bool
+value_is_resizable (const union value *value, int old_width, int new_width)
+{
+  int i;
+
+  if (val_type_from_width (old_width) != val_type_from_width (new_width))
+    return false;
+  for (i = new_width; i < old_width; i++)
+    if (value->s[i] != ' ')
+      return false;
+  return true;
+}
+
+/* Resizes VALUE from OLD_WIDTH to NEW_WIDTH.  The arguments must
+   satisfy the rules specified above for value_is_resizable. */
+void
+value_resize (union value *value, int old_width, int new_width)
+{
+  assert (value_is_resizable (value, old_width, new_width));
+  if (new_width > old_width)
+    memset (&value->s[old_width], ' ', new_width - old_width);
+}
+
+/* Compares A and B, which both have the given WIDTH, and returns
+   a strcmp()-type result. */
+int
+value_compare_3way (const union value *a, const union value *b, int width)
+{
+  return (width == 0
+          ? (a->f < b->f ? -1 : a->f > b->f)
+          : memcmp (a->s, b->s, width));
 }