--- /dev/null
+/* PSPP - a program for statistical analysis.
+ Copyright (C) 1997-9, 2000, 2006, 2007 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 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.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include <config.h>
+
+#include <data/case-map.h>
+
+#include <stdio.h>
+
+#include <data/dictionary.h>
+#include <data/variable.h>
+#include <data/case.h>
+#include <libpspp/alloc.h>
+#include <libpspp/assertion.h>
+
+/* A case map. */
+struct case_map
+ {
+ size_t value_cnt; /* Number of values in map. */
+ int *map; /* For each destination index, the
+ corresponding source index. */
+ };
+
+/* Creates and returns an empty map. */
+static struct case_map *
+create_case_map (size_t n)
+{
+ struct case_map *map;
+ size_t i;
+
+ map = xmalloc (sizeof *map);
+ map->value_cnt = n;
+ map->map = xnmalloc (n, sizeof *map->map);
+ for (i = 0; i < map->value_cnt; i++)
+ map->map[i] = -1;
+
+ return map;
+}
+
+/* Inserts into MAP a mapping of the CNT values starting at FROM
+ to the CNT values starting at TO. */
+static void
+insert_mapping (struct case_map *map, size_t from, size_t to, size_t cnt)
+{
+ size_t i;
+
+ assert (to + cnt <= map->value_cnt);
+ for (i = 0; i < cnt; i++)
+ {
+ assert (map->map[to + i] == -1);
+ map->map[to + i] = from + i;
+ }
+}
+
+/* Destroys case map MAP. */
+void
+case_map_destroy (struct case_map *map)
+{
+ if (map != NULL)
+ {
+ free (map->map);
+ free (map);
+ }
+}
+
+/* Maps from SRC to DST, applying case map MAP. */
+void
+case_map_execute (const struct case_map *map,
+ const struct ccase *src, struct ccase *dst)
+{
+ size_t dst_idx;
+
+ case_create (dst, map->value_cnt);
+ for (dst_idx = 0; dst_idx < map->value_cnt; dst_idx++)
+ {
+ int src_idx = map->map[dst_idx];
+ if (src_idx != -1)
+ *case_data_rw_idx (dst, dst_idx) = *case_data_idx (src, src_idx);
+ }
+}
+
+/* Returns the number of `union value's in cases created by
+ MAP. */
+size_t
+case_map_get_value_cnt (const struct case_map *map)
+{
+ return map->value_cnt;
+}
+
+/* Creates and returns a case_map that can be used to compact
+ cases for dictionary D.
+
+ Compacting a case eliminates "holes" between values and after
+ the last value. (Holes are created by deleting variables.)
+
+ All variables are compacted if EXCLUDE_CLASSES is 0, or it may
+ contain one or more of (1u << DC_ORDINARY), (1u << DC_SYSTEM),
+ or (1u << DC_SCRATCH) to cause the corresponding type of
+ variable to be deleted during compaction. */
+struct case_map *
+case_map_to_compact_dict (const struct dictionary *d,
+ unsigned int exclude_classes)
+{
+ size_t var_cnt;
+ struct case_map *map;
+ size_t value_idx;
+ size_t i;
+
+ assert ((exclude_classes & ~((1u << DC_ORDINARY)
+ | (1u << DC_SYSTEM)
+ | (1u << DC_SCRATCH))) == 0);
+
+ map = create_case_map (dict_count_values (d, exclude_classes));
+ var_cnt = dict_get_var_cnt (d);
+ value_idx = 0;
+ for (i = 0; i < var_cnt; i++)
+ {
+ struct variable *v = dict_get_var (d, i);
+ enum dict_class class = dict_class_from_id (var_get_name (v));
+
+ if (!(exclude_classes & (1u << class)))
+ {
+ size_t value_cnt = var_get_value_cnt (v);
+ insert_mapping (map, var_get_case_index (v), value_idx, value_cnt);
+ value_idx += value_cnt;
+ }
+ }
+ assert (value_idx == map->value_cnt);
+
+ return map;
+}
+
+/* Prepares dictionary D for producing a case map. Afterward,
+ the caller may delete, reorder, or rename variables within D
+ at will before using case_map_from_dict() to produce the case
+ map.
+
+ Uses D's aux members, which must otherwise not be in use. */
+void
+case_map_prepare_dict (const struct dictionary *d)
+{
+ size_t var_cnt = dict_get_var_cnt (d);
+ size_t i;
+
+ for (i = 0; i < var_cnt; i++)
+ {
+ struct variable *v = dict_get_var (d, i);
+ int *src_fv = xmalloc (sizeof *src_fv);
+ *src_fv = var_get_case_index (v);
+ var_attach_aux (v, src_fv, var_dtor_free);
+ }
+}
+
+/* Produces a case map from dictionary D, which must have been
+ previously prepared with case_map_prepare_dict().
+
+ Does not retain any reference to D, and clears the aux members
+ set up by case_map_prepare_dict().
+
+ Returns the new case map, or a null pointer if no mapping is
+ required (that is, no data has changed position). */
+struct case_map *
+case_map_from_dict (const struct dictionary *d)
+{
+ struct case_map *map;
+ size_t var_cnt = dict_get_var_cnt (d);
+ size_t i;
+ bool identity_map = true;
+
+ map = create_case_map (dict_get_next_value_idx (d));
+ for (i = 0; i < var_cnt; i++)
+ {
+ struct variable *v = dict_get_var (d, i);
+ size_t value_cnt = var_get_value_cnt (v);
+ int *src_fv = (int *) var_detach_aux (v);
+
+ if (var_get_case_index (v) != *src_fv)
+ identity_map = false;
+
+ insert_mapping (map, *src_fv, var_get_case_index (v), value_cnt);
+
+ free (src_fv);
+ }
+
+ if (identity_map)
+ {
+ case_map_destroy (map);
+ return NULL;
+ }
+
+ while (map->value_cnt > 0 && map->map[map->value_cnt - 1] == -1)
+ map->value_cnt--;
+
+ return map;
+}
+
+/* Creates and returns a case map for mapping variables in OLD to
+ variables in NEW based on their name. For every variable in
+ NEW, there must be a variable in OLD with the same name, type,
+ and width. */
+struct case_map *
+case_map_by_name (const struct dictionary *old,
+ const struct dictionary *new)
+{
+ struct case_map *map;
+ size_t var_cnt = dict_get_var_cnt (new);
+ size_t i;
+
+ map = create_case_map (dict_get_next_value_idx (new));
+ for (i = 0; i < var_cnt; i++)
+ {
+ struct variable *nv = dict_get_var (new, i);
+ struct variable *ov = dict_lookup_var_assert (old, var_get_name (nv));
+ assert (var_get_width (nv) == var_get_width (ov));
+ insert_mapping (map, var_get_case_index (ov), var_get_case_index (nv),
+ var_get_value_cnt (ov));
+ }
+ return map;
+}
+
+/* Prints the mapping represented by case map CM to stdout, for
+ debugging purposes. */
+void
+case_map_dump (const struct case_map *cm)
+{
+ int i;
+ for (i = 0 ; i < cm->value_cnt; ++i )
+ printf ("%d -> %d\n", i, cm->map[i]);
+}
projects / pspp-builds.git / blobdiff