1 /* PSPP - a program for statistical analysis.
2 Copyright (C) 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/>. */
19 #include "scratch-writer.h"
23 #include <data/case.h>
24 #include <data/case-map.h>
25 #include <data/casereader.h>
26 #include <data/casewriter-provider.h>
27 #include <data/casewriter.h>
28 #include <data/dictionary.h>
29 #include <data/file-handle-def.h>
30 #include <data/scratch-handle.h>
31 #include <data/variable.h>
32 #include <libpspp/compiler.h>
33 #include <libpspp/taint.h>
37 #define N_(msgid) (msgid)
39 /* A scratch file writer. */
42 struct file_handle *fh; /* Underlying file handle. */
43 struct fh_lock *lock; /* Exclusive access to file handle. */
44 struct dictionary *dict; /* Dictionary for subwriter. */
45 struct case_map *compactor; /* Compacts into dictionary. */
46 struct casewriter *subwriter; /* Data output. */
49 static const struct casewriter_class scratch_writer_casewriter_class;
51 /* Opens FH, which must have referent type FH_REF_SCRATCH, and
52 returns a scratch_writer for it, or a null pointer on
53 failure. Cases stored in the scratch_writer will be expected
54 to be drawn from DICTIONARY. */
56 scratch_writer_open (struct file_handle *fh,
57 const struct dictionary *dictionary)
59 struct scratch_writer *writer;
60 struct casewriter *casewriter;
62 size_t dict_value_cnt;
64 /* Get exclusive write access to handle. */
65 /* TRANSLATORS: this fragment will be interpolated into
66 messages in fh_lock() that identify types of files. */
67 lock = fh_lock (fh, FH_REF_SCRATCH, N_("scratch file"), FH_ACC_WRITE, true);
72 writer = xmalloc (sizeof *writer);
74 writer->fh = fh_ref (fh);
76 writer->dict = dict_clone (dictionary);
77 dict_delete_scratch_vars (writer->dict);
78 if (dict_count_values (writer->dict, 0)
79 < dict_get_next_value_idx (writer->dict))
81 writer->compactor = case_map_to_compact_dict (writer->dict, 0);
82 dict_compact_values (writer->dict);
85 writer->compactor = NULL;
86 dict_value_cnt = dict_get_next_value_idx (writer->dict);
87 writer->subwriter = autopaging_writer_create (dict_value_cnt);
89 casewriter = casewriter_create (dict_value_cnt,
90 &scratch_writer_casewriter_class, writer);
91 taint_propagate (casewriter_get_taint (writer->subwriter),
92 casewriter_get_taint (casewriter));
96 /* Writes case C to WRITER. */
98 scratch_writer_casewriter_write (struct casewriter *w UNUSED, void *writer_,
101 struct scratch_writer *writer = writer_;
102 casewriter_write (writer->subwriter,
103 case_map_execute (writer->compactor, c));
108 scratch_writer_casewriter_destroy (struct casewriter *w UNUSED, void *writer_)
110 static unsigned int next_unique_id = 0x12345678;
112 struct scratch_writer *writer = writer_;
113 struct casereader *reader = casewriter_make_reader (writer->subwriter);
114 if (!casereader_error (reader))
116 /* Destroy previous contents of handle. */
117 struct scratch_handle *sh = fh_get_scratch_handle (writer->fh);
119 scratch_handle_destroy (sh);
121 /* Create new contents. */
122 sh = xmalloc (sizeof *sh);
123 sh->unique_id = ++next_unique_id;
124 sh->dictionary = writer->dict;
125 sh->casereader = reader;
126 fh_set_scratch_handle (writer->fh, sh);
130 casereader_destroy (reader);
131 dict_destroy (writer->dict);
134 fh_unlock (writer->lock);
135 fh_unref (writer->fh);
139 static const struct casewriter_class scratch_writer_casewriter_class =
141 scratch_writer_casewriter_write,
142 scratch_writer_casewriter_destroy,