1 /* PSPP - a program for statistical analysis.
2 Copyright (C) 1997-9, 2000, 2006, 2009 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation, either version 3 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 #include <data/case.h>
24 #include <data/casereader.h>
25 #include <data/casewriter.h>
26 #include <data/casewriter-provider.h>
27 #include <data/settings.h>
28 #include <data/subcase.h>
29 #include <libpspp/array.h>
30 #include <libpspp/assertion.h>
31 #include <math/merge.h>
36 #define _(msgid) gettext (msgid)
38 /* These should only be changed for testing purposes. */
40 int max_buffers = INT_MAX;
44 struct caseproto *proto;
45 struct subcase ordering;
47 struct pqueue *pqueue;
49 struct casewriter *run;
51 struct ccase *run_end;
54 static struct casewriter_class sort_casewriter_class;
56 static struct pqueue *pqueue_create (const struct subcase *,
57 const struct caseproto *);
58 static void pqueue_destroy (struct pqueue *);
59 static bool pqueue_is_full (const struct pqueue *);
60 static bool pqueue_is_empty (const struct pqueue *);
61 static void pqueue_push (struct pqueue *, struct ccase *, casenumber);
62 static struct ccase *pqueue_pop (struct pqueue *, casenumber *);
64 static void output_record (struct sort_writer *);
67 sort_create_writer (const struct subcase *ordering,
68 const struct caseproto *proto)
70 struct sort_writer *sort;
72 sort = xmalloc (sizeof *sort);
73 sort->proto = caseproto_ref (proto);
74 subcase_clone (&sort->ordering, ordering);
75 sort->merge = merge_create (ordering, proto);
76 sort->pqueue = pqueue_create (ordering, proto);
81 return casewriter_create (proto, &sort_casewriter_class, sort);
85 sort_casewriter_write (struct casewriter *writer UNUSED, void *sort_,
88 struct sort_writer *sort = sort_;
91 if (pqueue_is_full (sort->pqueue))
94 next_run = (sort->run_end == NULL
95 || subcase_compare_3way (&sort->ordering, c,
96 &sort->ordering, sort->run_end) < 0);
97 pqueue_push (sort->pqueue, c, sort->run_id + (next_run ? 1 : 0));
101 sort_casewriter_destroy (struct casewriter *writer UNUSED, void *sort_)
103 struct sort_writer *sort = sort_;
105 subcase_destroy (&sort->ordering);
106 merge_destroy (sort->merge);
107 pqueue_destroy (sort->pqueue);
108 casewriter_destroy (sort->run);
109 case_unref (sort->run_end);
110 caseproto_unref (sort->proto);
114 static struct casereader *
115 sort_casewriter_convert_to_reader (struct casewriter *writer, void *sort_)
117 struct sort_writer *sort = sort_;
118 struct casereader *output;
120 if (sort->run == NULL && sort->run_id == 0)
123 sort->run = mem_writer_create (sort->proto);
126 while (!pqueue_is_empty (sort->pqueue))
127 output_record (sort);
129 merge_append (sort->merge, casewriter_make_reader (sort->run));
132 output = merge_make_reader (sort->merge);
133 sort_casewriter_destroy (writer, sort);
138 output_record (struct sort_writer *sort)
140 struct ccase *min_case;
141 casenumber min_run_id;
143 min_case = pqueue_pop (sort->pqueue, &min_run_id);
145 printf ("\toutput: %f to run %d\n", case_num_idx (min_case, 0), min_run_id);
148 if (sort->run_id != min_run_id && sort->run != NULL)
150 merge_append (sort->merge, casewriter_make_reader (sort->run));
153 if (sort->run == NULL)
155 sort->run = tmpfile_writer_create (sort->proto);
156 sort->run_id = min_run_id;
159 case_unref (sort->run_end);
160 sort->run_end = case_ref (min_case);
161 casewriter_write (sort->run, min_case);
164 static struct casewriter_class sort_casewriter_class =
166 sort_casewriter_write,
167 sort_casewriter_destroy,
168 sort_casewriter_convert_to_reader,
171 /* Reads all the cases from INPUT. Sorts the cases according to
172 ORDERING. Returns the sorted cases in a new casereader. */
174 sort_execute (struct casereader *input, const struct subcase *ordering)
176 struct casewriter *output =
177 sort_create_writer (ordering, casereader_get_proto (input));
178 casereader_transfer (input, output);
179 return casewriter_make_reader (output);
182 /* Reads all the cases from INPUT. Sorts the cases in ascending
183 order according to VARIABLE. Returns the sorted cases in a
186 sort_execute_1var (struct casereader *input, const struct variable *var)
189 struct casereader *reader;
191 subcase_init_var (&sc, var, SC_ASCEND);
192 reader = sort_execute (input, &sc);
193 subcase_destroy (&sc);
199 struct subcase ordering;
200 struct pqueue_record *records;
213 static int compare_pqueue_records_minheap (const void *a, const void *b,
216 static struct pqueue *
217 pqueue_create (const struct subcase *ordering, const struct caseproto *proto)
221 pq = xmalloc (sizeof *pq);
222 subcase_clone (&pq->ordering, ordering);
223 pq->record_cap = settings_get_workspace_cases (proto);
224 if (pq->record_cap > max_buffers)
225 pq->record_cap = max_buffers;
226 else if (pq->record_cap < min_buffers)
227 pq->record_cap = min_buffers;
229 pq->records = xnmalloc (pq->record_cap, sizeof *pq->records);
236 pqueue_destroy (struct pqueue *pq)
240 while (!pqueue_is_empty (pq))
243 struct ccase *c = pqueue_pop (pq, &id);
246 subcase_destroy (&pq->ordering);
253 pqueue_is_full (const struct pqueue *pq)
255 return pq->record_cnt >= pq->record_cap;
259 pqueue_is_empty (const struct pqueue *pq)
261 return pq->record_cnt == 0;
265 pqueue_push (struct pqueue *pq, struct ccase *c, casenumber id)
267 struct pqueue_record *r;
269 assert (!pqueue_is_full (pq));
271 r = &pq->records[pq->record_cnt++];
276 push_heap (pq->records, pq->record_cnt, sizeof *pq->records,
277 compare_pqueue_records_minheap, pq);
280 static struct ccase *
281 pqueue_pop (struct pqueue *pq, casenumber *id)
283 struct pqueue_record *r;
285 assert (!pqueue_is_empty (pq));
287 pop_heap (pq->records, pq->record_cnt--, sizeof *pq->records,
288 compare_pqueue_records_minheap, pq);
290 r = &pq->records[pq->record_cnt];
295 /* Compares record-run tuples A and B on id, then on case data,
296 then on insertion order, in descending order. */
298 compare_pqueue_records_minheap (const void *a_, const void *b_,
301 const struct pqueue_record *a = a_;
302 const struct pqueue_record *b = b_;
303 const struct pqueue *pq = pq_;
304 int result = a->id < b->id ? -1 : a->id > b->id;
306 result = subcase_compare_3way (&pq->ordering, a->c, &pq->ordering, b->c);
308 result = a->idx < b->idx ? -1 : a->idx > b->idx;