-/* PSPP - computes sample statistics.
- Copyright (C) 2004 Free Software Foundation, Inc.
- Written by Ben Pfaff <blp@gnu.org>.
+/* PSPP - a program for statistical analysis.
+ Copyright (C) 2004, 2007, 2009 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/>. */
-#ifndef HEADER_CASE
-#define HEADER_CASE
+#ifndef DATA_CASE_H
+#define DATA_CASE_H 1
+#include <limits.h>
#include <stddef.h>
#include <stdbool.h>
-#include "value.h"
+#include <stdlib.h>
+#include <libpspp/compiler.h>
+#include <data/caseproto.h>
-/* Opaque structure that represents a case. Use accessor
- functions instead of accessing any members directly. Use
- case_move() or case_clone() instead of copying. */
-struct ccase
- {
- struct case_data *case_data; /* Actual data. */
-#if GLOBAL_DEBUGGING
- struct ccase *this; /* Detects unauthorized move/copy. */
-#endif
- };
+struct variable;
-/* Invisible to user code. */
-struct case_data
+/* A count of cases or the index of a case within a collection of
+ them. */
+#define CASENUMBER_MAX LONG_MAX
+typedef long int casenumber;
+
+/* Reference-counted case implementation.
+
+ A newly created case has a single owner (the code that created
+ it), represented by an initial reference count of 1. Other
+ code that receives the case may keep a virtual copy of it by
+ calling case_ref, which increments the case's reference count.
+ When this is done, the case becomes shared between its
+ original owner and each piece of code that incremented the
+ reference count.
+
+ A shared case (one whose reference count is greater than 1)
+ must not be modified, because this would make the case change
+ in the view of every reference count holder, not just the one
+ that intended to change the case. Because the purpose of
+ keeping the reference count is to make a virtual copy of the
+ case, this is undesirable behavior. The case_unshare function
+ provides a solution, by making a new, unshared copy of a
+ shared case. */
+struct ccase
{
- size_t value_cnt; /* Number of values. */
- unsigned ref_cnt; /* Reference count. */
- union value values[1]; /* Values. */
+ struct caseproto *proto; /* Case prototype. */
+ size_t ref_cnt; /* Reference count. */
+ union value values[1]; /* Values. */
};
-#ifdef GLOBAL_DEBUGGING
-#define CASE_INLINE
-#else
-#define CASE_INLINE static
-#endif
+struct ccase *case_create (const struct caseproto *) MALLOC_LIKE;
+struct ccase *case_try_create (const struct caseproto *) MALLOC_LIKE;
+struct ccase *case_clone (const struct ccase *) MALLOC_LIKE;
-CASE_INLINE void case_nullify (struct ccase *);
-CASE_INLINE int case_is_null (const struct ccase *);
+static inline struct ccase *case_unshare (struct ccase *) WARN_UNUSED_RESULT;
+static inline struct ccase *case_ref (const struct ccase *);
+static inline void case_unref (struct ccase *);
+static inline bool case_is_shared (const struct ccase *);
-void case_create (struct ccase *, size_t value_cnt);
-CASE_INLINE void case_clone (struct ccase *, const struct ccase *);
-CASE_INLINE void case_move (struct ccase *, struct ccase *);
-CASE_INLINE void case_destroy (struct ccase *);
+static inline size_t case_get_value_cnt (const struct ccase *);
+static inline const struct caseproto *case_get_proto (const struct ccase *);
-void case_resize (struct ccase *, size_t old_cnt, size_t new_cnt);
-void case_swap (struct ccase *, struct ccase *);
+size_t case_get_cost (const struct caseproto *);
-int case_try_create (struct ccase *, size_t value_cnt);
-int case_try_clone (struct ccase *, const struct ccase *);
+struct ccase *case_resize (struct ccase *, const struct caseproto *)
+ WARN_UNUSED_RESULT;
+struct ccase *case_unshare_and_resize (struct ccase *,
+ const struct caseproto *)
+ WARN_UNUSED_RESULT;
-CASE_INLINE void case_copy (struct ccase *dst, size_t dst_idx,
- const struct ccase *src, size_t src_idx,
- size_t cnt);
+void case_set_missing (struct ccase *);
-CASE_INLINE void case_to_values (const struct ccase *, union value *, size_t);
-CASE_INLINE void case_from_values (struct ccase *,
- const union value *, size_t);
+void case_copy (struct ccase *dst, size_t dst_idx,
+ const struct ccase *src, size_t src_idx,
+ size_t cnt);
+void case_copy_out (const struct ccase *,
+ size_t start_idx, union value *, size_t n_values);
+void case_copy_in (struct ccase *,
+ size_t start_idx, const union value *, size_t n_values);
-CASE_INLINE const union value *case_data (const struct ccase *, size_t idx);
-CASE_INLINE double case_num (const struct ccase *, size_t idx);
-CASE_INLINE const char *case_str (const struct ccase *, size_t idx);
+const union value *case_data (const struct ccase *, const struct variable *);
+const union value *case_data_idx (const struct ccase *, size_t idx);
+union value *case_data_rw (struct ccase *, const struct variable *);
+union value *case_data_rw_idx (struct ccase *, size_t idx);
-CASE_INLINE union value *case_data_rw (struct ccase *, size_t idx);
+double case_num (const struct ccase *, const struct variable *);
+double case_num_idx (const struct ccase *, size_t idx);
+
+const uint8_t *case_str (const struct ccase *, const struct variable *);
+const uint8_t *case_str_idx (const struct ccase *, size_t idx);
+uint8_t *case_str_rw (struct ccase *, const struct variable *);
+uint8_t *case_str_rw_idx (struct ccase *, size_t idx);
-struct variable;
int case_compare (const struct ccase *, const struct ccase *,
- struct variable *const *, size_t var_cnt);
+ const struct variable *const *, size_t n_vars);
int case_compare_2dict (const struct ccase *, const struct ccase *,
- struct variable *const *, struct variable *const *,
- size_t var_cnt);
+ const struct variable *const *,
+ const struct variable *const *,
+ size_t n_vars);
const union value *case_data_all (const struct ccase *);
union value *case_data_all_rw (struct ccase *);
-
-void case_unshare (struct ccase *);
-
-#ifndef GLOBAL_DEBUGGING
-#include <stdlib.h>
-#include "str.h"
-
-static inline void
-case_nullify (struct ccase *c)
+\f
+struct ccase *case_unshare__ (struct ccase *);
+void case_unref__ (struct ccase *);
+
+/* If C is a shared case, that is, if it has a reference count
+ greater than 1, makes a new unshared copy and returns it,
+ decrementing C's reference count. If C is not shared (its
+ reference count is 1), returns C.
+
+ This function should be used before attempting to modify any
+ of the data in a case that might be shared, e.g.:
+ c = case_unshare (c); // Make sure that C is not shared.
+ case_data_rw (c, myvar)->f = 1; // Modify data in C.
+*/
+static inline struct ccase *
+case_unshare (struct ccase *c)
{
- c->case_data = NULL;
+ if (case_is_shared (c))
+ c = case_unshare__ (c);
+ return c;
}
-static inline int
-case_is_null (const struct ccase *c)
+/* Increments case C's reference count and returns C. Afterward,
+ case C is shared among its reference count holders. */
+static inline struct ccase *
+case_ref (const struct ccase *c_)
{
- return c->case_data == NULL;
+ struct ccase *c = (struct ccase *) c_;
+ c->ref_cnt++;
+ return c;
}
-static inline void
-case_clone (struct ccase *clone, const struct ccase *orig)
-{
- *clone = *orig;
- orig->case_data->ref_cnt++;
-}
+/* Decrements case C's reference count. Frees C if its
+ reference count drops to 0.
+ If C is a null pointer, this function has no effect. */
static inline void
-case_move (struct ccase *dst, struct ccase *src)
-{
- *dst = *src;
- src->case_data = NULL;
-}
-
-static inline void
-case_destroy (struct ccase *c)
-{
- struct case_data *cd = c->case_data;
- if (cd != NULL && --cd->ref_cnt == 0)
- free (cd);
-}
-
-static inline void
-case_copy (struct ccase *dst, size_t dst_idx,
- const struct ccase *src, size_t src_idx,
- size_t value_cnt)
-{
- if (dst->case_data->ref_cnt > 1)
- case_unshare (dst);
- if (dst->case_data != src->case_data || dst_idx != src_idx)
- memmove (dst->case_data->values + dst_idx,
- src->case_data->values + src_idx,
- sizeof *dst->case_data->values * value_cnt);
-}
-
-static inline void
-case_to_values (const struct ccase *c, union value *output,
- size_t output_size )
-{
- memcpy (output, c->case_data->values,
- output_size * sizeof *output);
-}
-
-static inline void
-case_from_values (struct ccase *c, const union value *input,
- size_t input_size UNUSED)
-{
- if (c->case_data->ref_cnt > 1)
- case_unshare (c);
- memcpy (c->case_data->values, input,
- c->case_data->value_cnt * sizeof *input);
-}
-
-static inline const union value *
-case_data (const struct ccase *c, size_t idx)
+case_unref (struct ccase *c)
{
- return &c->case_data->values[idx];
+ if (c != NULL && !--c->ref_cnt)
+ case_unref__ (c);
}
-static inline double
-case_num (const struct ccase *c, size_t idx)
+/* Returns true if case C is shared. A case that is shared
+ cannot be modified directly. Instead, an unshared copy must
+ first be made with case_unshare(). */
+static inline bool
+case_is_shared (const struct ccase *c)
{
- return c->case_data->values[idx].f;
+ return c->ref_cnt > 1;
}
-static inline const char *
-case_str (const struct ccase *c, size_t idx)
+/* Returns the number of union values in C. */
+static inline size_t
+case_get_value_cnt (const struct ccase *c)
{
- return c->case_data->values[idx].s;
+ return caseproto_get_n_widths (c->proto);
}
-static inline union value *
-case_data_rw (struct ccase *c, size_t idx)
+/* Returns the prototype that describes the format of case C.
+ The caller must not unref the returned prototype. */
+static inline const struct caseproto *
+case_get_proto (const struct ccase *c)
{
- if (c->case_data->ref_cnt > 1)
- case_unshare (c);
- return &c->case_data->values[idx];
+ return c->proto;
}
-#endif /* !GLOBAL_DEBUGGING */
-#endif /* case.h */
+#endif /* data/case.h */
projects / pspp-builds.git / blobdiff