/* PSPP - a program for statistical analysis.
- Copyright (C) 2006 Free Software Foundation, Inc.
+ Copyright (C) 2006, 2007, 2009 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
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
+/* Infrastructure common to system file reader and writer.
+
+ Old versions of SPSS limited string variables to a width of
+ 255 bytes. For backward compatibility with these older
+ versions, the system file format represents a string longer
+ than 255 bytes, called a "very long string", as a collection
+ of strings no longer than 255 bytes each. The strings
+ concatenated to make a very long string are called its
+ "segments"; for consistency, variables other than very long
+ strings are considered to have a single segment.
+
+ The interfaces in this file primarily provide support for
+ dealing with very long strings. */
+
#ifndef DATA_SYS_FILE_PRIVATE_H
#define DATA_SYS_FILE_PRIVATE_H 1
-/* This nonsense is required for SPSS compatibility. */
+#include <stddef.h>
+
+struct dictionary;
+
+/* A variable in a system file. */
+struct sfm_var
+ {
+ int var_width; /* Variable width (0 to 32767). */
+ int segment_width; /* Segment width (0 to 255). */
+ int case_index; /* Index into case. */
+
+ /* The following members are interesting only for string
+ variables (width != 0). For numeric variables (width ==
+ 0) their values are always 0.
+
+ Note: width + padding is always a multiple of 8. */
+ int offset; /* Offset within string variable in case. */
+ int padding; /* Number of padding bytes following data. */
+ };
+
+int sfm_dictionary_to_sfm_vars (const struct dictionary *,
+ struct sfm_var **, size_t *);
-#define MIN_VERY_LONG_STRING 256
-#define EFFECTIVE_LONG_STRING_LENGTH (MIN_VERY_LONG_STRING - 4)
+int sfm_width_to_octs (int width);
+int sfm_width_to_segments (int width);
-int sfm_width_to_bytes (int width);
+int sfm_segment_effective_offset (int width, int segment);
+int sfm_segment_alloc_width (int width, int segment);
#endif /* data/sys-file-private.h */