X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fdata%2Fvalue.h;h=6955eea0bd358e144fc1bd4ff8ed9e615aa7b68f;hb=a34c42168e0cd3373860a6cc3f518cb0e329db47;hp=8f1746337ea37ceaefa3523fa73ff0c2666b63f8;hpb=5c3291dc396b795696e94f47780308fd7ace6fc4;p=pspp-builds.git

diff --git a/src/data/value.h b/src/data/value.h
index 8f174633..6955eea0 100644
--- a/src/data/value.h
+++ b/src/data/value.h
@@ -23,8 +23,12 @@
 #include <string.h>
 #include "xalloc.h"
 
+/* Maximum length of a "short" string, that is represented in
+   "union value" without a separate pointer.
+
+   This is an implementation detail of the "union value" code.
+   There is little reason for client code to use it. */
 #define MAX_SHORT_STRING 8
-#define MIN_LONG_STRING (MAX_SHORT_STRING + 1)
 
 /* A numeric or string value.
 
@@ -54,9 +58,6 @@ static inline double value_num (const union value *);
 static inline const char *value_str (const union value *, int width);
 static inline char *value_str_rw (union value *, int width);
 
-int compare_values (const void *, const void *, const void *var);
-unsigned hash_value (const void *, const void *var);
-
 static inline void value_copy (union value *, const union value *, int width);
 void value_copy_rpad (union value *, int dst_width,
                       const union value *, int src_width,
@@ -68,12 +69,14 @@ void value_copy_buf_rpad (union value *dst, int dst_width,
 void value_set_missing (union value *, int width);
 int value_compare_3way (const union value *, const union value *, int width);
 bool value_equal (const union value *, const union value *, int width);
-size_t value_hash (const union value *, int width, unsigned int basis);
+unsigned int value_hash (const union value *, int width, unsigned int basis);
 
 bool value_is_resizable (const union value *, int old_width, int new_width);
 bool value_needs_resize (int old_width, int new_width);
 void value_resize (union value *, int old_width, int new_width);
 
+static inline void value_swap (union value *, union value *);
+
 struct pool;
 void value_init_pool (struct pool *, union value *, int width);
 void value_resize_pool (struct pool *, union value *,
@@ -148,7 +151,7 @@ static inline const char *
 value_str (const union value *v, int width)
 {
   assert (width > 0);
-  return (width >= MIN_LONG_STRING ? v->long_string : v->short_string);
+  return (width > MAX_SHORT_STRING ? v->long_string : v->short_string);
 }
 
 /* Returns the string value in V, which must have width WIDTH.
@@ -162,7 +165,7 @@ static inline char *
 value_str_rw (union value *v, int width)
 {
   assert (width > 0);
-  return (width >= MIN_LONG_STRING ? v->long_string : v->short_string);
+  return (width > MAX_SHORT_STRING ? v->long_string : v->short_string);
 }
 
 /* Copies SRC to DST, given that they both contain data of the
@@ -176,4 +179,13 @@ value_copy (union value *dst, const union value *src, int width)
     memcpy (dst->long_string, src->long_string, width);
 }
 
+/* Exchanges the contents of A and B. */
+static inline void
+value_swap (union value *a, union value *b)
+{
+  union value tmp = *a;
+  *a = *b;
+  *b = tmp;
+}
+
 #endif /* data/value.h */