1 /* PSPP - computes sample statistics.
2 Copyright (C) 1997-9, 2000 Free Software Foundation, Inc.
3 Written by Ben Pfaff <blp@gnu.org>.
5 This program is free software; you can redistribute it and/or
6 modify it under the terms of the GNU General Public License as
7 published by the Free Software Foundation; either version 2 of the
8 License, or (at your option) any later version.
10 This program is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
27 typedef struct write_case_data *write_case_data;
28 typedef bool write_case_func (write_case_data);
30 /* The current active file, from which cases are read. */
31 extern struct case_source *vfm_source;
36 const struct case_source_class *class; /* Class. */
37 void *aux; /* Auxiliary data. */
40 /* A case source class. */
41 struct case_source_class
43 const char *name; /* Identifying name. */
45 /* Returns the exact number of cases that READ will pass to
46 WRITE_CASE, if known, or -1 otherwise. */
47 int (*count) (const struct case_source *);
49 /* Reads the cases one by one into C and for each one calls
50 WRITE_CASE passing the given AUX data.
51 Returns true if successful, false if an I/O error occurred. */
52 bool (*read) (struct case_source *,
54 write_case_func *write_case, write_case_data aux);
56 /* Destroys the source. */
57 void (*destroy) (struct case_source *);
60 extern const struct case_source_class storage_source_class;
61 extern const struct case_source_class file_type_source_class;
62 extern const struct case_source_class input_program_source_class;
65 struct case_source *create_case_source (const struct case_source_class *,
67 void free_case_source (struct case_source *);
69 int case_source_is_complex (const struct case_source *);
70 int case_source_is_class (const struct case_source *,
71 const struct case_source_class *);
73 struct casefile *storage_source_get_casefile (struct case_source *);
74 struct case_source *storage_source_create (struct casefile *);
76 /* The replacement active file, to which cases are written. */
77 extern struct case_sink *vfm_sink;
82 const struct case_sink_class *class; /* Class. */
83 void *aux; /* Auxiliary data. */
84 size_t value_cnt; /* Number of `union value's in case. */
87 /* A case sink class. */
88 struct case_sink_class
90 const char *name; /* Identifying name. */
92 /* Opens the sink for writing. */
93 void (*open) (struct case_sink *);
95 /* Writes a case to the sink. */
96 bool (*write) (struct case_sink *, const struct ccase *);
98 /* Closes and destroys the sink. */
99 void (*destroy) (struct case_sink *);
101 /* Closes the sink and returns a source that can read back
102 the cases that were written, perhaps transformed in some
103 way. The sink must still be separately destroyed by
104 calling destroy(). */
105 struct case_source *(*make_source) (struct case_sink *);
108 extern const struct case_sink_class storage_sink_class;
109 extern const struct case_sink_class null_sink_class;
111 struct case_sink *create_case_sink (const struct case_sink_class *,
112 const struct dictionary *,
114 void case_sink_open (struct case_sink *);
115 void case_sink_write (struct case_sink *, const struct ccase *);
116 void case_sink_destroy (struct case_sink *);
117 void free_case_sink (struct case_sink *);
119 /* Number of cases to lag. */
122 bool procedure (bool (*proc_func) (struct ccase *, void *aux), void *aux);
123 bool procedure_with_splits (void (*begin_func) (void *aux),
124 bool (*proc_func) (struct ccase *, void *aux),
125 void (*end_func) (void *aux),
127 struct ccase *lagged_case (int n_before);
129 bool multipass_procedure_with_splits (bool (*) (const struct casefile *,
133 time_t vfm_last_invocation (void);