1 /* PSPP - computes sample statistics.
2 Copyright (C) 2006 Free Software Foundation, Inc.
4 This program is free software; you can redistribute it and/or
5 modify it under the terms of the GNU General Public License as
6 published by the Free Software Foundation; either version 2 of the
7 License, or (at your option) any later version.
9 This program is distributed in the hope that it will be useful, but
10 WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 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, write to the Free Software
16 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21 #include "scratch-writer.h"
25 #include <data/case.h>
26 #include <data/casereader.h>
27 #include <data/casewriter-provider.h>
28 #include <data/casewriter.h>
29 #include <data/dictionary.h>
30 #include <data/file-handle-def.h>
31 #include <data/scratch-handle.h>
32 #include <libpspp/compiler.h>
33 #include <libpspp/taint.h>
37 /* A scratch file writer. */
40 struct scratch_handle *handle; /* Underlying scratch handle. */
41 struct file_handle *fh; /* Underlying file handle. */
42 struct dict_compactor *compactor; /* Compacts into handle->dictionary. */
43 struct casewriter *subwriter; /* Data output. */
46 static struct casewriter_class scratch_writer_casewriter_class;
48 /* Opens FH, which must have referent type FH_REF_SCRATCH, and
49 returns a scratch_writer for it, or a null pointer on
50 failure. Cases stored in the scratch_writer will be expected
51 to be drawn from DICTIONARY. */
53 scratch_writer_open (struct file_handle *fh,
54 const struct dictionary *dictionary)
56 struct scratch_handle *sh;
57 struct scratch_writer *writer;
58 struct dictionary *scratch_dict;
59 struct dict_compactor *compactor;
60 struct casewriter *casewriter;
62 if (!fh_open (fh, FH_REF_SCRATCH, "scratch file", "we"))
65 /* Destroy previous contents of handle. */
66 sh = fh_get_scratch_handle (fh);
68 scratch_handle_destroy (sh);
70 /* Copy the dictionary and compact if needed. */
71 scratch_dict = dict_clone (dictionary);
72 if (dict_compacting_would_shrink (scratch_dict))
74 compactor = dict_make_compactor (scratch_dict);
75 dict_compact_values (scratch_dict);
80 /* Create new contents. */
81 sh = xmalloc (sizeof *sh);
82 sh->dictionary = scratch_dict;
83 sh->casereader = NULL;
86 writer = xmalloc (sizeof *writer);
89 writer->compactor = compactor;
90 writer->subwriter = autopaging_writer_create (dict_get_next_value_idx (
93 fh_set_scratch_handle (fh, sh);
94 casewriter = casewriter_create (&scratch_writer_casewriter_class, writer);
95 taint_propagate (casewriter_get_taint (writer->subwriter),
96 casewriter_get_taint (casewriter));
100 /* Writes case C to WRITER. */
102 scratch_writer_casewriter_write (struct casewriter *w UNUSED, void *writer_,
105 struct scratch_writer *writer = writer_;
106 struct scratch_handle *handle = writer->handle;
108 if (writer->compactor)
110 case_create (&tmp, dict_get_next_value_idx (handle->dictionary));
111 dict_compactor_compact (writer->compactor, &tmp, c);
116 casewriter_write (writer->subwriter, &tmp);
121 scratch_writer_casewriter_destroy (struct casewriter *w UNUSED, void *writer_)
123 struct scratch_writer *writer = writer_;
124 struct casereader *reader = casewriter_make_reader (writer->subwriter);
125 if (!casereader_error (reader))
126 writer->handle->casereader = reader;
127 fh_close (writer->fh, "scratch file", "we");
131 static struct casewriter_class scratch_writer_casewriter_class =
133 scratch_writer_casewriter_write,
134 scratch_writer_casewriter_destroy,