03fefbc6c510f45556c76237472c1139895e7365
1 /*
2 * PostRR - src/cdata.c
3 * Copyright (C) 2012 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 /*
29 * A PostgreSQL data-type providing consolidated data points.
30 */
32 #include "postrr.h"
34 #include <errno.h>
35 #include <string.h>
37 #include <postgres.h>
38 #include <fmgr.h>
40 /* Postgres utilities */
41 #include <catalog/pg_type.h>
42 #include <utils/array.h>
44 enum {
45 CF_AVG = 0,
46 CF_MIN = 1,
47 CF_MAX = 2
48 };
50 #define CF_TO_STR(cf) \
51 (((cf) == CF_AVG) \
52 ? "AVG" \
53 : ((cf) == CF_MIN) \
54 ? "MIN" \
55 : ((cf) == CF_MAX) \
56 ? "MAX" : "UNKNOWN")
58 /*
59 * data type
60 */
62 struct cdata {
63 float8 value;
64 int32 undef_num;
65 int32 val_num;
66 int32 cf;
67 };
69 /*
70 * prototypes for PostgreSQL functions
71 */
73 PG_FUNCTION_INFO_V1(cdata_validate);
75 PG_FUNCTION_INFO_V1(cdata_in);
76 PG_FUNCTION_INFO_V1(cdata_out);
77 PG_FUNCTION_INFO_V1(cdata_typmodin);
78 PG_FUNCTION_INFO_V1(cdata_typmodout);
80 PG_FUNCTION_INFO_V1(cdata_to_cdata);
81 PG_FUNCTION_INFO_V1(int32_to_cdata);
82 PG_FUNCTION_INFO_V1(cdata_to_float8);
84 PG_FUNCTION_INFO_V1(cdata_update);
86 /*
87 * public API
88 */
90 Datum
91 cdata_validate(PG_FUNCTION_ARGS)
92 {
93 char type_info[1024];
94 char *result;
95 size_t req_len;
96 size_t len;
98 if (PG_NARGS() != 1)
99 ereport(ERROR, (
100 errmsg("cdata_validate() expect one argument"),
101 errhint("Usage cdata_validate(expected_size)")
102 ));
104 req_len = (size_t)PG_GETARG_UINT32(0);
105 len = sizeof(cdata_t);
107 if (req_len != len)
108 ereport(ERROR, (
109 errmsg("length of the cdata type "
110 "does not match the expected length"),
111 errhint("Please report a bug against PostRR")
112 ));
114 snprintf(type_info, sizeof(type_info),
115 "cdata validated successfully; type length = %zu", len);
116 type_info[sizeof(type_info) - 1] = '\0';
118 result = pstrdup(type_info);
119 PG_RETURN_CSTRING(result);
120 } /* cdata_validate */
122 Datum
123 cdata_in(PG_FUNCTION_ARGS)
124 {
125 cdata_t *data;
126 int32 typmod;
128 char *val_str, *orig;
129 char *endptr = NULL;
131 if (PG_NARGS() != 3)
132 ereport(ERROR, (
133 errmsg("cdata_in() expects three arguments"),
134 errhint("Usage: cdata_in(col_name, oid, typmod)")
135 ));
137 data = (cdata_t *)palloc0(sizeof(*data));
139 val_str = PG_GETARG_CSTRING(0);
140 typmod = PG_GETARG_INT32(2);
142 orig = val_str;
143 while ((*val_str != '\0') && isspace((int)*val_str))
144 ++val_str;
146 if (*val_str == '\0')
147 ereport(ERROR, (
148 errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
149 errmsg("invalid input syntax for cdata: \"%s\"", orig)
150 ));
152 errno = 0;
153 data->value = strtod(val_str, &endptr);
154 data->val_num = 1;
156 if ((endptr == val_str) || errno)
157 ereport(ERROR, (
158 errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
159 errmsg("invalid input syntax for cdata: \"%s\"", orig)
160 ));
162 while ((*endptr != '\0') && isspace((int)*endptr))
163 ereport(ERROR, (
164 errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
165 errmsg("invalid input syntax for cdata: \"%s\"", orig)
166 ));
168 if (typmod > 0)
169 data->cf = typmod;
170 else
171 data->cf = 0;
173 PG_RETURN_CDATA_P(data);
174 } /* cdata_in */
176 Datum
177 cdata_out(PG_FUNCTION_ARGS)
178 {
179 cdata_t *data;
181 char cd_str[1024];
182 char *result;
184 if (PG_NARGS() != 1)
185 ereport(ERROR, (
186 errmsg("cdata_out() expects one argument"),
187 errhint("Usage: cdata_out(cdata)")
188 ));
190 data = PG_GETARG_CDATA_P(0);
192 snprintf(cd_str, sizeof(cd_str), "%g (U:%i/%i)",
193 data->value, data->undef_num, data->val_num);
195 result = pstrdup(cd_str);
196 PG_RETURN_CSTRING(result);
197 } /* cdata_out */
199 Datum
200 cdata_typmodin(PG_FUNCTION_ARGS)
201 {
202 ArrayType *tm_array;
204 Datum *elem_values;
205 int n;
206 char *cf_str;
207 int32 typmod = CF_AVG;
209 if (PG_NARGS() != 1)
210 ereport(ERROR, (
211 errmsg("cdata_typmodin() expects one argument"),
212 errhint("Usage: cdata_typmodin(array)")
213 ));
215 tm_array = PG_GETARG_ARRAYTYPE_P(0);
217 if (ARR_ELEMTYPE(tm_array) != CSTRINGOID)
218 ereport(ERROR, (
219 errcode(ERRCODE_ARRAY_ELEMENT_ERROR),
220 errmsg("typmod array must be type cstring[]")
221 ));
223 if (ARR_NDIM(tm_array) != 1)
224 ereport(ERROR, (
225 errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
226 errmsg("typmod array must be one-dimensional")
227 ));
229 deconstruct_array(tm_array, CSTRINGOID,
230 /* elmlen = */ -2, /* elmbyval = */ false, /* elmalign = */ 'c',
231 &elem_values, /* nullsp = */ NULL, &n);
233 if (n != 1)
234 ereport(ERROR, (
235 errcode(ERRCODE_INVALID_PARAMETER_VALUE),
236 errmsg("cdata typmod array must have one element")
237 ));
239 cf_str = DatumGetCString(elem_values[0]);
240 if (! strcasecmp(cf_str, "AVG"))
241 typmod = CF_AVG;
242 else if (! strcasecmp(cf_str, "MIN"))
243 typmod = CF_MIN;
244 else if (! strcasecmp(cf_str, "MAX"))
245 typmod = CF_MAX;
246 else
247 ereport(ERROR, (
248 errcode(ERRCODE_INVALID_PARAMETER_VALUE),
249 errmsg("invalid cdata typmod: %s", cf_str)
250 ));
252 PG_RETURN_INT32(typmod);
253 } /* cdata_typmodin */
255 Datum
256 cdata_typmodout(PG_FUNCTION_ARGS)
257 {
258 int32 typmod;
259 char tm_str[32];
260 char *result;
262 if (PG_NARGS() != 1)
263 ereport(ERROR, (
264 errmsg("cdata_typmodout() expects one argument"),
265 errhint("Usage: cdata_typmodout(typmod)")
266 ));
268 typmod = PG_GETARG_INT32(0);
269 snprintf(tm_str, sizeof(tm_str), "('%s')", CF_TO_STR(typmod));
270 tm_str[sizeof(tm_str) - 1] = '\0';
271 result = pstrdup(tm_str);
272 PG_RETURN_CSTRING(result);
273 } /* cdata_typmodout */
275 Datum
276 cdata_to_cdata(PG_FUNCTION_ARGS)
277 {
278 cdata_t *data;
279 int32 typmod;
281 if (PG_NARGS() != 3)
282 ereport(ERROR, (
283 errmsg("cdata_to_cdata() "
284 "expects three arguments"),
285 errhint("Usage: cdata_to_cdata"
286 "(cdata, typmod, is_explicit)")
287 ));
289 data = PG_GETARG_CDATA_P(0);
290 typmod = PG_GETARG_INT32(1);
292 if ((data->cf >= 0) && (data->cf != typmod) && (data->val_num > 1))
293 ereport(ERROR, (
294 errcode(ERRCODE_INVALID_PARAMETER_VALUE),
295 errmsg("invalid cast: cannot cast cdata "
296 "with different typmod (yet)")
297 ));
299 data->cf = typmod;
300 PG_RETURN_CDATA_P(data);
301 } /* cdata_to_cdata */
303 Datum
304 int32_to_cdata(PG_FUNCTION_ARGS)
305 {
306 int32 i_val;
307 int32 typmod;
309 cdata_t *data;
311 if (PG_NARGS() != 3)
312 ereport(ERROR, (
313 errmsg("int32_to_cdata() expects three arguments"),
314 errhint("Usage: int32_to_cdata"
315 "(integer, typmod, is_explicit)")
316 ));
318 i_val = PG_GETARG_INT32(0);
319 typmod = PG_GETARG_INT32(1);
321 data = (cdata_t *)palloc0(sizeof(*data));
323 data->value = (float8)i_val;
324 data->undef_num = 0;
325 data->val_num = 1;
327 if (typmod >= 0)
328 data->cf = typmod;
329 else
330 data->cf = CF_AVG;
332 PG_RETURN_CDATA_P(data);
333 } /* int32_to_cdata */
335 Datum
336 cdata_to_float8(PG_FUNCTION_ARGS)
337 {
338 cdata_t *data;
340 if (PG_NARGS() != 1)
341 ereport(ERROR, (
342 errmsg("cdata_to_float8() expects one argument"),
343 errhint("Usage: cdata_to_float8(cdata)")
344 ));
346 data = PG_GETARG_CDATA_P(0);
347 PG_RETURN_FLOAT8(data->value);
348 } /* cdata_to_float8 */
350 Datum
351 cdata_update(PG_FUNCTION_ARGS)
352 {
353 cdata_t *data;
354 cdata_t *update;
356 if (PG_NARGS() != 2)
357 ereport(ERROR, (
358 errmsg("cdata_update() expects two arguments"),
359 errhint("Usage: cdata_update(cdata, cdata)")
360 ));
362 data = PG_GETARG_CDATA_P(0);
363 update = PG_GETARG_CDATA_P(1);
365 if ((data->cf != update->cf) && (update->val_num > 1))
366 ereport(ERROR, (
367 errcode(ERRCODE_INVALID_PARAMETER_VALUE),
368 errmsg("invalid update value: incompatible "
369 "consolidation function")
370 ));
372 switch (data->cf) {
373 case CF_AVG:
374 data->value = (data->value * (data->val_num - data->undef_num))
375 + (update->value * (update->val_num - update->undef_num));
376 data->value /= (data->val_num - data->undef_num)
377 + (update->val_num - update->undef_num);
378 break;
379 case CF_MIN:
380 data->value = (data->value <= update->value)
381 ? data->value : update->value;
382 break;
383 case CF_MAX:
384 data->value = (data->value >= update->value)
385 ? data->value : update->value;
386 break;
387 default:
388 ereport(ERROR, (
389 errcode(ERRCODE_DATA_CORRUPTED),
390 errmsg("unknown consolidation function %d",
391 data->cf)
392 ));
393 break;
394 }
396 data->undef_num += update->undef_num;
397 data->val_num += update->val_num;
398 PG_RETURN_CDATA_P(data);
399 } /* cdata_update */
401 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */