Merge branch 'master' into rewrite-sheet

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

diff --git a/src/data/value.c b/src/data/value.c
index e9411c8cefa976ff4a4c46d94db837e9eefffb23..9fcf1cbb9b8fa0a97cb4e75544a9a6892879ab68 100644 (file)
--- a/src/data/value.c
+++ b/src/data/value.c
@@ -15,10 +15,12 @@
    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"
 
@@ -30,13 +32,27 @@ 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 (const void *a_, const void *b_, const void *var_)
 {
+  const union value *a = a_;
+  const union value *b = b_;
+  const struct variable *var = var_;
+  int width = var_get_width (var);
   return (width == 0
           ? (a->f < b->f ? -1 : a->f > b->f)
           : memcmp (a->s, b->s, MIN (MAX_SHORT_STRING, width)));
@@ -45,13 +61,17 @@ compare_values (const union value *a, const union value *b, int width)
 /* 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)
+hash_value (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
@@ -73,3 +93,32 @@ value_set_missing (union value *v, int width)
   else
     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);
+}