1 /*
2 * SysDB - src/include/core/data.h
3 * Copyright (C) 2012-2014 Sebastian 'tokkee' Harl <sh@tokkee.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
17 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
28 #ifndef SDB_CORE_DATA_H
29 #define SDB_CORE_DATA_H 1
31 #include "core/time.h"
33 #include <inttypes.h>
34 #include <stddef.h>
36 #ifdef __cplusplus
37 extern "C" {
38 #endif
40 enum {
41 SDB_TYPE_INTEGER = 1,
42 SDB_TYPE_DECIMAL,
43 SDB_TYPE_STRING,
44 SDB_TYPE_DATETIME,
45 SDB_TYPE_BINARY,
46 };
48 #define SDB_TYPE_TO_STRING(t) \
49 (((t) == SDB_TYPE_INTEGER) \
50 ? "INTEGER" \
51 : ((t) == SDB_TYPE_DECIMAL) \
52 ? "DECIMAL" \
53 : ((t) == SDB_TYPE_STRING) \
54 ? "STRING" \
55 : ((t) == SDB_TYPE_DATETIME) \
56 ? "DATETIME" \
57 : ((t) == SDB_TYPE_BINARY) \
58 ? "BINARY" \
59 : "UNKNOWN")
61 /*
62 * sdb_data_t:
63 * A datum retrieved from an arbitrary data source.
64 */
65 typedef struct {
66 int type;
67 union {
68 int64_t integer; /* SDB_TYPE_INTEGER */
69 double decimal; /* SDB_TYPE_DECIMAL */
70 char *string; /* SDB_TYPE_STRING */
71 sdb_time_t datetime; /* SDB_TYPE_DATETIME */
72 struct {
73 size_t length;
74 unsigned char *datum;
75 } binary; /* SDB_TYPE_BINARY */
76 } data;
77 } sdb_data_t;
79 /*
80 * sdb_data_copy:
81 * Copy the datum stored in 'src' to the memory location pointed to by 'dst'.
82 * Any dynamic data (strings, binary data) is copied to newly allocated
83 * memory. Use, for example, sdb_data_free_datum() to free any dynamic memory
84 * stored in a datum.
85 *
86 * Returns:
87 * - 0 on success
88 * - a negative value else
89 */
90 int
91 sdb_data_copy(sdb_data_t *dst, const sdb_data_t *src);
93 /*
94 * sdb_data_free_datum:
95 * Free any dynamic memory referenced by the specified datum. Does not free
96 * the memory allocated by the sdb_data_t object itself. This function must
97 * not be used if any static or stack memory is referenced from the data
98 * object.
99 */
100 void
101 sdb_data_free_datum(sdb_data_t *datum);
103 /*
104 * sdb_data_cmp:
105 * Compare two data points. A NULL datum is considered less than any non-NULL
106 * datum. On data-type mismatch, the function always returns a negative value.
107 *
108 * Returns:
109 * - a value less than zero if d1 compares less than d2
110 * - zero if d1 compares equal to d2
111 * - a value greater than zero if d1 compares greater than d2
112 */
113 int
114 sdb_data_cmp(sdb_data_t *d1, sdb_data_t *d2);
116 /*
117 * sdb_data_strlen:
118 * Returns a (worst-case) estimate for the number of bytes required to format
119 * the datum as a string. Does not take the terminating null byte into
120 * account.
121 */
122 size_t
123 sdb_data_strlen(sdb_data_t *datum);
125 enum {
126 SDB_UNQUOTED = 0,
127 SDB_SINGLE_QUOTED,
128 SDB_DOUBLE_QUOTED,
129 };
131 /*
132 * sdb_data_format:
133 * Output the specified datum to the specified string using a default format.
134 * The value of 'quoted' determines whether and how non-integer and
135 * non-decimal values are quoted. If the buffer size is less than the return
136 * value of sdb_data_strlen, the datum may be truncated. The buffer will
137 * always be nul-terminated after calling this function.
138 *
139 * Returns:
140 * - the number of characters written to the buffer (excluding the terminated
141 * null byte) or the number of characters which would have been written in
142 * case the output was truncated
143 * - a negative value else
144 */
145 int
146 sdb_data_format(sdb_data_t *datum, char *buf, size_t buflen, int quoted);
148 #ifdef __cplusplus
149 } /* extern "C" */
150 #endif
152 #endif /* ! SDB_CORE_DATA_H */
154 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */