/* PSPP - a program for statistical analysis.
- Copyright (C) 1997-9, 2000, 2007, 2009 Free Software Foundation, Inc.
+ Copyright (C) 1997-9, 2000, 2007, 2009, 2010, 2012 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
#ifndef DATA_VALUE_H
#define DATA_VALUE_H 1
+#include "libpspp/compiler.h"
#include <assert.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include "xalloc.h"
\f
-/* 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
-
-/* A numeric or string value.
-
- The client is responsible for keeping track of the value's
- width.
-
- This structure is semi-opaque:
-
- - If the value is a number, clients may access the 'f'
- member directly.
-
- - Clients should not access other members directly.
-*/
+/* A numeric or string value. The client is responsible for keeping track of
+ the value's width. */
union value
{
double f;
- uint8_t short_string[MAX_SHORT_STRING];
- uint8_t *long_string;
+ uint8_t *s;
};
static inline void value_init (union value *, int width);
+static inline void value_clone (union value *, const union value *, int width);
static inline bool value_needs_init (int width);
static inline bool value_try_init (union value *, int width);
static inline void value_destroy (union value *, int width);
-static inline double value_num (const union value *);
-static inline const uint8_t *value_str (const union value *, int width);
-static inline uint8_t *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,
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);
-unsigned int value_hash (const union value *, int width, unsigned int basis);
+unsigned int value_hash (const union value *, int width, unsigned int basis) WARN_UNUSED_RESULT;
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);
+bool value_is_spaces (const union value *, int width);
+
static inline void value_swap (union value *, union value *);
struct pool;
void value_init_pool (struct pool *, union value *, int width);
+void value_clone_pool (struct pool *, union value *, const union value *,
+ int width);
void value_resize_pool (struct pool *, union value *,
int old_width, int new_width);
\f
static inline void
value_init (union value *v, int width)
{
- if (width > MAX_SHORT_STRING)
- v->long_string = xmalloc (width);
+ if (width > 0)
+ v->s = xmalloc (width);
+}
+
+/* Initializes V as a value of the given WIDTH, as with value_init(), and
+ copies SRC's value into V as its initial value. */
+static inline void
+value_clone (union value *v, const union value *src, int width)
+{
+ if (width <= 0)
+ v->f = src->f;
+ else
+ v->s = xmemdup (src->s, width);
}
/* Returns true if a value of the given WIDTH actually needs to
static inline bool
value_needs_init (int width)
{
- return width > MAX_SHORT_STRING;
+ return width > 0;
}
/* Same as value_init, except that failure to allocate memory
static inline bool
value_try_init (union value *v, int width)
{
- if (width > MAX_SHORT_STRING)
+ if (width > 0)
{
- v->long_string = malloc (width);
- return v->long_string != NULL;
+ v->s = malloc (width);
+ return v->s != NULL;
}
else
return true;
static inline void
value_destroy (union value *v, int width)
{
- if (width > MAX_SHORT_STRING)
- free (v->long_string);
-}
-
-/* Returns the numeric value in V, which must have width 0. */
-static inline double
-value_num (const union value *v)
-{
- return v->f;
-}
-
-/* Returns the string value in V, which must have width WIDTH.
-
- The returned value is not null-terminated.
-
- It is important that WIDTH be the actual value that was passed
- to value_init. Passing, e.g., a smaller value because only
- that number of bytes will be accessed will not always work. */
-static inline const uint8_t *
-value_str (const union value *v, int width)
-{
- assert (width > 0);
- return (width > MAX_SHORT_STRING ? v->long_string : v->short_string);
-}
-
-/* Returns the string value in V, which must have width WIDTH.
-
- The returned value is not null-terminated.
-
- It is important that WIDTH be the actual value that was passed
- to value_init. Passing, e.g., a smaller value because only
- that number of bytes will be accessed will not always work. */
-static inline uint8_t *
-value_str_rw (union value *v, int width)
-{
- assert (width > 0);
- return (width > MAX_SHORT_STRING ? v->long_string : v->short_string);
+ if (width > 0)
+ free (v->s);
}
/* Copies SRC to DST, given that they both contain data of the
static inline void
value_copy (union value *dst, const union value *src, int width)
{
- if (width <= MAX_SHORT_STRING)
- *dst = *src;
- else if (dst != src)
- memcpy (dst->long_string, src->long_string, width);
+ if (width <= 0)
+ dst->f = src->f;
+ else
+ memcpy (dst->s, src->s, width);
}
/* Exchanges the contents of A and B. */