/* PSPP - a program for statistical analysis.
- Copyright (C) 1997-9, 2000, 2006, 2007, 2009 Free Software Foundation, Inc.
+ Copyright (C) 1997-9, 2000, 2006, 2007, 2009, 2011, 2013 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
#include <config.h>
-#include <data/case-map.h>
+#include "data/case-map.h"
#include <stdio.h>
#include <stdlib.h>
-#include <data/casereader.h>
-#include <data/casewriter.h>
-#include <data/dictionary.h>
-#include <data/variable.h>
-#include <data/case.h>
-#include <libpspp/assertion.h>
+#include "data/casereader.h"
+#include "data/casewriter.h"
+#include "data/dictionary.h"
+#include "data/variable.h"
+#include "data/case.h"
+#include "libpspp/assertion.h"
+#include "libpspp/hash-functions.h"
+#include "libpspp/hmap.h"
-#include "xalloc.h"
+#include "gl/xalloc.h"
/* A case map. */
struct case_map
}
/* Creates and returns a new casereader whose cases are produced
- by reading from SUBREADER and executing the actions of MAP.
+ by reading from SUBREADER and executing the actions of MAP.
The casereader will have as many `union value's as MAP. When
the new casereader is destroyed, MAP will be destroyed too.
when the returned casereader is destroyed. */
struct casereader *
case_map_create_input_translator (struct case_map *map,
- struct casereader *subreader)
+ struct casereader *subreader)
{
return casereader_create_translator (subreader,
case_map_get_proto (map),
when the returned casewriter is destroyed. */
struct casewriter *
case_map_create_output_translator (struct case_map *map,
- struct casewriter *subwriter)
+ struct casewriter *subwriter)
{
return casewriter_create_translator (subwriter,
case_map_get_proto (map),
return map;
}
+\f
+struct stage_var
+ {
+ struct hmap_node hmap_node; /* In struct case_map_stage's 'stage_vars'. */
+ const struct variable *var;
+ int case_index;
+ };
-/* 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
+struct case_map_stage
+ {
+ const struct dictionary *dict;
+ struct hmap stage_vars;
+ };
+
+/* Prepares and returns a "struct case_map_stage" for producing a case map for
+ DICT. Afterward, the caller may delete, reorder, or rename variables within
+ DICT at will before using case_map_stage_get_case_map() 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)
+ The caller must *not* add new variables to DICT. */
+struct case_map_stage *
+case_map_stage_create (const struct dictionary *dict)
{
- size_t var_cnt = dict_get_var_cnt (d);
+ size_t n_vars = dict_get_var_cnt (dict);
+ struct case_map_stage *stage;
size_t i;
- for (i = 0; i < var_cnt; i++)
+ stage = xmalloc (sizeof *stage);
+ stage->dict = dict;
+ hmap_init (&stage->stage_vars);
+
+ for (i = 0; i < n_vars; 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);
+ const struct variable *var = dict_get_var (dict, i);
+ struct stage_var *stage_var;
+
+ stage_var = xmalloc (sizeof *stage_var);
+ stage_var->var = var;
+ stage_var->case_index = var_get_case_index (var);
+ hmap_insert (&stage->stage_vars, &stage_var->hmap_node,
+ hash_pointer (var, 0));
+ }
+
+ return stage;
+}
+
+/* Destroys STAGE, which was created by case_map_stage_create(). */
+void
+case_map_stage_destroy (struct case_map_stage *stage)
+{
+ if (stage != NULL)
+ {
+ struct stage_var *stage_var, *next_stage_var;
+
+ HMAP_FOR_EACH_SAFE (stage_var, next_stage_var,
+ struct stage_var, hmap_node, &stage->stage_vars)
+ {
+ hmap_delete (&stage->stage_vars, &stage_var->hmap_node);
+ free (stage_var);
+ }
+ hmap_destroy (&stage->stage_vars);
+ free (stage);
}
}
-/* Produces a case map from dictionary D, which must have been
- previously prepared with case_map_prepare_dict().
+static const struct stage_var *
+case_map_stage_find_var (const struct case_map_stage *stage,
+ const struct variable *var)
+{
+ const struct stage_var *stage_var;
+
+ HMAP_FOR_EACH_IN_BUCKET (stage_var, struct stage_var, hmap_node,
+ hash_pointer (var, 0), &stage->stage_vars)
+ if (stage_var->var == var)
+ return stage_var;
+
+ /* If the following assertion is reached, it indicates a bug in the
+ case_map_stage client: the client allowed a new variable to be added to
+ the dictionary. This is not allowed, because of the risk that the new
+ varaible might have the same address as an old variable that has been
+ deleted. */
+ NOT_REACHED ();
+}
- Does not retain any reference to D, and clears the aux members
- set up by case_map_prepare_dict().
+/* Produces a case map from STAGE, which must have been previously created with
+ case_map_stage_create(). The case map maps from the original case index of
+ the variables in STAGE's dictionary to their current case indexes.
- Returns the new case map, or a null pointer if no mapping is
- required (that is, no data has changed position). */
+ 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)
+case_map_stage_get_case_map (const struct case_map_stage *stage)
{
struct case_map *map;
- size_t var_cnt = dict_get_var_cnt (d);
+ size_t n_vars = dict_get_var_cnt (stage->dict);
size_t n_values;
size_t i;
bool identity_map = true;
- map = create_case_map (dict_get_proto (d));
- for (i = 0; i < var_cnt; i++)
+ map = create_case_map (dict_get_proto (stage->dict));
+ for (i = 0; i < n_vars; i++)
{
- struct variable *v = dict_get_var (d, i);
- int *src_fv = var_detach_aux (v);
+ const struct variable *var = dict_get_var (stage->dict, i);
+ const struct stage_var *stage_var = case_map_stage_find_var (stage, var);
- if (var_get_case_index (v) != *src_fv)
+ if (var_get_case_index (var) != stage_var->case_index)
identity_map = false;
- insert_mapping (map, *src_fv, var_get_case_index (v));
-
- free (src_fv);
+ insert_mapping (map, stage_var->case_index, var_get_case_index (var));
}
if (identity_map)