1 /*-------------------------------------------------------------------------
2 *
3 * array.h
4 * Declarations for Postgres arrays.
5 *
6 * A standard varlena array has the following internal structure:
7 * <vl_len_> - standard varlena header word
8 * <ndim> - number of dimensions of the array
9 * <dataoffset> - offset to stored data, or 0 if no nulls bitmap
10 * <elemtype> - element type OID
11 * <dimensions> - length of each array axis (C array of int)
12 * <lower bnds> - lower boundary of each dimension (C array of int)
13 * <null bitmap> - bitmap showing locations of nulls (OPTIONAL)
14 * <actual data> - whatever is the stored data
15 *
16 * The <dimensions> and <lower bnds> arrays each have ndim elements.
17 *
18 * The <null bitmap> may be omitted if the array contains no NULL elements.
19 * If it is absent, the <dataoffset> field is zero and the offset to the
20 * stored data must be computed on-the-fly. If the bitmap is present,
21 * <dataoffset> is nonzero and is equal to the offset from the array start
22 * to the first data element (including any alignment padding). The bitmap
23 * follows the same conventions as tuple null bitmaps, ie, a 1 indicates
24 * a non-null entry and the LSB of each bitmap byte is used first.
25 *
26 * The actual data starts on a MAXALIGN boundary. Individual items in the
27 * array are aligned as specified by the array element type. They are
28 * stored in row-major order (last subscript varies most rapidly).
29 *
30 * NOTE: it is important that array elements of toastable datatypes NOT be
31 * toasted, since the tupletoaster won't know they are there. (We could
32 * support compressed toasted items; only out-of-line items are dangerous.
33 * However, it seems preferable to store such items uncompressed and allow
34 * the toaster to compress the whole array as one input.)
35 *
36 *
37 * The OIDVECTOR and INT2VECTOR datatypes are storage-compatible with
38 * generic arrays, but they support only one-dimensional arrays with no
39 * nulls (and no null bitmap). They don't support being toasted, either.
40 *
41 * There are also some "fixed-length array" datatypes, such as NAME and
42 * POINT. These are simply a sequence of a fixed number of items each
43 * of a fixed-length datatype, with no overhead; the item size must be
44 * a multiple of its alignment requirement, because we do no padding.
45 * We support subscripting on these types, but array_in() and array_out()
46 * only work with varlena arrays.
47 *
48 * In addition, arrays are a major user of the "expanded object" TOAST
49 * infrastructure. This allows a varlena array to be converted to a
50 * separate representation that may include "deconstructed" Datum/isnull
51 * arrays holding the elements.
52 *
53 *
54 * Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
55 * Portions Copyright (c) 1994, Regents of the University of California
56 *
57 * src/include/utils/array.h
58 *
59 *-------------------------------------------------------------------------
60 */
61 #ifndef ARRAY_H
62 #define ARRAY_H
63
64 #include "fmgr.h"
65 #include "utils/expandeddatum.h"
66
67 /* avoid including execnodes.h here */
68 struct ExprState;
69 struct ExprContext;
70
71
72 /*
73 * Arrays are varlena objects, so must meet the varlena convention that
74 * the first int32 of the object contains the total object size in bytes.
75 * Be sure to use VARSIZE() and SET_VARSIZE() to access it, though!
76 *
77 * CAUTION: if you change the header for ordinary arrays you will also
78 * need to change the headers for oidvector and int2vector!
79 */
80 typedef struct
81 {
82 int32 vl_len_; /* varlena header (do not touch directly!) */
83 int ndim; /* # of dimensions */
84 int32 dataoffset; /* offset to data, or 0 if no bitmap */
85 Oid elemtype; /* element type OID */
86 } ArrayType;
87
88 /*
89 * An expanded array is contained within a private memory context (as
90 * all expanded objects must be) and has a control structure as below.
91 *
92 * The expanded array might contain a regular "flat" array if that was the
93 * original input and we've not modified it significantly. Otherwise, the
94 * contents are represented by Datum/isnull arrays plus dimensionality and
95 * type information. We could also have both forms, if we've deconstructed
96 * the original array for access purposes but not yet changed it. For pass-
97 * by-reference element types, the Datums would point into the flat array in
98 * this situation. Once we start modifying array elements, new pass-by-ref
99 * elements are separately palloc'd within the memory context.
100 */
101 #define EA_MAGIC 689375833 /* ID for debugging crosschecks */
102
103 typedef struct ExpandedArrayHeader
104 {
105 /* Standard header for expanded objects */
106 ExpandedObjectHeader hdr;
107
108 /* Magic value identifying an expanded array (for debugging only) */
109 int ea_magic;
110
111 /* Dimensionality info (always valid) */
112 int ndims; /* # of dimensions */
113 int *dims; /* array dimensions */
114 int *lbound; /* index lower bounds for each dimension */
115
116 /* Element type info (always valid) */
117 Oid element_type; /* element type OID */
118 int16 typlen; /* needed info about element datatype */
119 bool typbyval;
120 char typalign;
121
122 /*
123 * If we have a Datum-array representation of the array, it's kept here;
124 * else dvalues/dnulls are NULL. The dvalues and dnulls arrays are always
125 * palloc'd within the object private context, but may change size from
126 * time to time. For pass-by-ref element types, dvalues entries might
127 * point either into the fstartptr..fendptr area, or to separately
128 * palloc'd chunks. Elements should always be fully detoasted, as they
129 * are in the standard flat representation.
130 *
131 * Even when dvalues is valid, dnulls can be NULL if there are no null
132 * elements.
133 */
134 Datum *dvalues; /* array of Datums */
135 bool *dnulls; /* array of is-null flags for Datums */
136 int dvalueslen; /* allocated length of above arrays */
137 int nelems; /* number of valid entries in above arrays */
138
139 /*
140 * flat_size is the current space requirement for the flat equivalent of
141 * the expanded array, if known; otherwise it's 0. We store this to make
142 * consecutive calls of get_flat_size cheap.
143 */
144 Size flat_size;
145
146 /*
147 * fvalue points to the flat representation if it is valid, else it is
148 * NULL. If we have or ever had a flat representation then
149 * fstartptr/fendptr point to the start and end+1 of its data area; this
150 * is so that we can tell which Datum pointers point into the flat
151 * representation rather than being pointers to separately palloc'd data.
152 */
153 ArrayType *fvalue; /* must be a fully detoasted array */
154 char *fstartptr; /* start of its data area */
155 char *fendptr; /* end+1 of its data area */
156 } ExpandedArrayHeader;
157
158 /*
159 * Functions that can handle either a "flat" varlena array or an expanded
160 * array use this union to work with their input. Don't refer to "flt";
161 * instead, cast to ArrayType. This struct nominally requires 8-byte
162 * alignment on 64-bit, but it's often used for an ArrayType having 4-byte
163 * alignment. UBSan complains about referencing "flt" in such cases.
164 */
165 typedef union AnyArrayType
166 {
167 ArrayType flt;
168 ExpandedArrayHeader xpn;
169 } AnyArrayType;
170
171 /*
172 * working state for accumArrayResult() and friends
Twine(NodeKind Kind)173 * note that the input must be scalars (legal array elements)
174 */
175 typedef struct ArrayBuildState
176 {
177 MemoryContext mcontext; /* where all the temp stuff is kept */
178 Datum *dvalues; /* array of accumulated Datums */
179 bool *dnulls; /* array of is-null flags for Datums */
180 int alen; /* allocated length of above arrays */
181 int nelems; /* number of valid entries in above arrays */
182 Oid element_type; /* data type of the Datums */
183 int16 typlen; /* needed info about datatype */
184 bool typbyval;
185 char typalign;
186 bool private_cxt; /* use private memory context */
187 } ArrayBuildState;
188
189 /*
190 * working state for accumArrayResultArr() and friends
191 * note that the input must be arrays, and the same array type is returned
isNull()192 */
193 typedef struct ArrayBuildStateArr
194 {
195 MemoryContext mcontext; /* where all the temp stuff is kept */
196 char *data; /* accumulated data */
197 bits8 *nullbitmap; /* bitmap of is-null flags, or NULL if none */
198 int abytes; /* allocated length of "data" */
199 int nbytes; /* number of bytes used so far */
200 int aitems; /* allocated length of bitmap (in elements) */
201 int nitems; /* total number of elements in result */
202 int ndims; /* current dimensions of result */
203 int dims[MAXDIM];
204 int lbs[MAXDIM];
205 Oid array_type; /* data type of the arrays */
206 Oid element_type; /* data type of the array elements */
207 bool private_cxt; /* use private memory context */
208 } ArrayBuildStateArr;
209
210 /*
211 * working state for accumArrayResultAny() and friends
isBinary()212 * these functions handle both cases
213 */
214 typedef struct ArrayBuildStateAny
215 {
216 /* Exactly one of these is not NULL: */
217 ArrayBuildState *scalarstate;
218 ArrayBuildStateArr *arraystate;
219 } ArrayBuildStateAny;
220
221 /*
222 * structure to cache type metadata needed for array manipulation
223 */
224 typedef struct ArrayMetaState
225 {
226 Oid element_type;
227 int16 typlen;
228 bool typbyval;
229 char typalign;
230 char typdelim;
231 Oid typioparam;
232 Oid typiofunc;
233 FmgrInfo proc;
234 } ArrayMetaState;
235
236 /*
237 * private state needed by array_map (here because caller must provide it)
238 */
239 typedef struct ArrayMapState
240 {
241 ArrayMetaState inp_extra;
242 ArrayMetaState ret_extra;
getLHSKind()243 } ArrayMapState;
244
245 /* ArrayIteratorData is private in arrayfuncs.c */
getRHSKind()246 typedef struct ArrayIteratorData *ArrayIterator;
247
248 /* fmgr macros for regular varlena array objects */
249 #define DatumGetArrayTypeP(X) ((ArrayType *) PG_DETOAST_DATUM(X))
250 #define DatumGetArrayTypePCopy(X) ((ArrayType *) PG_DETOAST_DATUM_COPY(X))
251 #define PG_GETARG_ARRAYTYPE_P(n) DatumGetArrayTypeP(PG_GETARG_DATUM(n))
252 #define PG_GETARG_ARRAYTYPE_P_COPY(n) DatumGetArrayTypePCopy(PG_GETARG_DATUM(n))
253 #define PG_RETURN_ARRAYTYPE_P(x) PG_RETURN_POINTER(x)
254
255 /* fmgr macros for expanded array objects */
256 #define PG_GETARG_EXPANDED_ARRAY(n) DatumGetExpandedArray(PG_GETARG_DATUM(n))
257 #define PG_GETARG_EXPANDED_ARRAYX(n, metacache) \
258 DatumGetExpandedArrayX(PG_GETARG_DATUM(n), metacache)
259 #define PG_RETURN_EXPANDED_ARRAY(x) PG_RETURN_DATUM(EOHPGetRWDatum(&(x)->hdr))
Twine()260
261 /* fmgr macros for AnyArrayType (ie, get either varlena or expanded form) */
262 #define PG_GETARG_ANY_ARRAY_P(n) DatumGetAnyArrayP(PG_GETARG_DATUM(n))
263
264 /*
265 * Access macros for varlena array header fields.
266 *
267 * ARR_DIMS returns a pointer to an array of array dimensions (number of
268 * elements along the various array axes).
269 *
270 * ARR_LBOUND returns a pointer to an array of array lower bounds.
271 *
272 * That is: if the third axis of an array has elements 5 through 8, then
273 * ARR_DIMS(a)[2] == 4 and ARR_LBOUND(a)[2] == 5.
274 *
275 * Unlike C, the default lower bound is 1.
276 */
277 #define ARR_SIZE(a) VARSIZE(a)
278 #define ARR_NDIM(a) ((a)->ndim)
279 #define ARR_HASNULL(a) ((a)->dataoffset != 0)
280 #define ARR_ELEMTYPE(a) ((a)->elemtype)
281
282 #define ARR_DIMS(a) \
283 ((int *) (((char *) (a)) + sizeof(ArrayType)))
284 #define ARR_LBOUND(a) \
285 ((int *) (((char *) (a)) + sizeof(ArrayType) + \
286 sizeof(int) * ARR_NDIM(a)))
287
288 #define ARR_NULLBITMAP(a) \
289 (ARR_HASNULL(a) ? \
290 (bits8 *) (((char *) (a)) + sizeof(ArrayType) + \
291 2 * sizeof(int) * ARR_NDIM(a)) \
292 : (bits8 *) NULL)
293
294 /*
295 * The total array header size (in bytes) for an array with the specified
296 * number of dimensions and total number of items.
297 */
298 #define ARR_OVERHEAD_NONULLS(ndims) \
299 MAXALIGN(sizeof(ArrayType) + 2 * sizeof(int) * (ndims))
300 #define ARR_OVERHEAD_WITHNULLS(ndims, nitems) \
301 MAXALIGN(sizeof(ArrayType) + 2 * sizeof(int) * (ndims) + \
302 ((nitems) + 7) / 8)
303
304 #define ARR_DATA_OFFSET(a) \
305 (ARR_HASNULL(a) ? (a)->dataoffset : ARR_OVERHEAD_NONULLS(ARR_NDIM(a)))
306
307 /*
308 * Returns a pointer to the actual array data.
309 */
310 #define ARR_DATA_PTR(a) \
311 (((char *) (a)) + ARR_DATA_OFFSET(a))
312
313 /*
314 * Macros for working with AnyArrayType inputs. Beware multiple references!
315 */
316 #define AARR_NDIM(a) \
317 (VARATT_IS_EXPANDED_HEADER(a) ? \
318 (a)->xpn.ndims : ARR_NDIM((ArrayType *) (a)))
319 #define AARR_HASNULL(a) \
320 (VARATT_IS_EXPANDED_HEADER(a) ? \
321 ((a)->xpn.dvalues != NULL ? (a)->xpn.dnulls != NULL : ARR_HASNULL((a)->xpn.fvalue)) : \
322 ARR_HASNULL((ArrayType *) (a)))
323 #define AARR_ELEMTYPE(a) \
324 (VARATT_IS_EXPANDED_HEADER(a) ? \
325 (a)->xpn.element_type : ARR_ELEMTYPE((ArrayType *) (a)))
326 #define AARR_DIMS(a) \
327 (VARATT_IS_EXPANDED_HEADER(a) ? \
328 (a)->xpn.dims : ARR_DIMS((ArrayType *) (a)))
329 #define AARR_LBOUND(a) \
330 (VARATT_IS_EXPANDED_HEADER(a) ? \
331 (a)->xpn.lbound : ARR_LBOUND((ArrayType *) (a)))
332
333
334 /*
335 * GUC parameter
336 */
337 extern bool Array_nulls;
338
339 /*
340 * prototypes for functions defined in arrayfuncs.c
Twine(unsigned Val)341 */
342 extern void CopyArrayEls(ArrayType *array,
343 Datum *values,
344 bool *nulls,
345 int nitems,
346 int typlen,
347 bool typbyval,
348 char typalign,
349 bool freedata);
350
Twine(const unsigned long & Val)351 extern Datum array_get_element(Datum arraydatum, int nSubscripts, int *indx,
352 int arraytyplen, int elmlen, bool elmbyval, char elmalign,
353 bool *isNull);
354 extern Datum array_set_element(Datum arraydatum, int nSubscripts, int *indx,
355 Datum dataValue, bool isNull,
Twine(const long & Val)356 int arraytyplen, int elmlen, bool elmbyval, char elmalign);
357 extern Datum array_get_slice(Datum arraydatum, int nSubscripts,
358 int *upperIndx, int *lowerIndx,
359 bool *upperProvided, bool *lowerProvided,
360 int arraytyplen, int elmlen, bool elmbyval, char elmalign);
Twine(const unsigned long long & Val)361 extern Datum array_set_slice(Datum arraydatum, int nSubscripts,
362 int *upperIndx, int *lowerIndx,
363 bool *upperProvided, bool *lowerProvided,
364 Datum srcArrayDatum, bool isNull,
365 int arraytyplen, int elmlen, bool elmbyval, char elmalign);
Twine(const long long & Val)366
367 extern Datum array_ref(ArrayType *array, int nSubscripts, int *indx,
368 int arraytyplen, int elmlen, bool elmbyval, char elmalign,
369 bool *isNull);
370 extern ArrayType *array_set(ArrayType *array, int nSubscripts, int *indx,
371 Datum dataValue, bool isNull,
372 int arraytyplen, int elmlen, bool elmbyval, char elmalign);
373
374 extern Datum array_map(Datum arrayd,
375 struct ExprState *exprstate, struct ExprContext *econtext,
Twine(const char * LHS,const StringRef & RHS)376 Oid retType, ArrayMapState *amstate);
377
378 extern void array_bitmap_copy(bits8 *destbitmap, int destoffset,
379 const bits8 *srcbitmap, int srcoffset,
380 int nitems);
381
382 extern ArrayType *construct_array(Datum *elems, int nelems,
383 Oid elmtype,
384 int elmlen, bool elmbyval, char elmalign);
Twine(const StringRef & LHS,const char * RHS)385 extern ArrayType *construct_md_array(Datum *elems,
386 bool *nulls,
387 int ndims,
388 int *dims,
389 int *lbs,
390 Oid elmtype, int elmlen, bool elmbyval, char elmalign);
391 extern ArrayType *construct_empty_array(Oid elmtype);
392 extern ExpandedArrayHeader *construct_empty_expanded_array(Oid element_type,
393 MemoryContext parentcontext,
394 ArrayMetaState *metacache);
395 extern void deconstruct_array(ArrayType *array,
396 Oid elmtype,
397 int elmlen, bool elmbyval, char elmalign,
398 Datum **elemsp, bool **nullsp, int *nelemsp);
createNull()399 extern bool array_contains_nulls(ArrayType *array);
400
401 extern ArrayBuildState *initArrayResult(Oid element_type,
402 MemoryContext rcontext, bool subcontext);
403 extern ArrayBuildState *accumArrayResult(ArrayBuildState *astate,
404 Datum dvalue, bool disnull,
405 Oid element_type,
406 MemoryContext rcontext);
407 extern Datum makeArrayResult(ArrayBuildState *astate,
utohexstr(const uint64_t & Val)408 MemoryContext rcontext);
409 extern Datum makeMdArrayResult(ArrayBuildState *astate, int ndims,
410 int *dims, int *lbs, MemoryContext rcontext, bool release);
411
412 extern ArrayBuildStateArr *initArrayResultArr(Oid array_type, Oid element_type,
413 MemoryContext rcontext, bool subcontext);
414 extern ArrayBuildStateArr *accumArrayResultArr(ArrayBuildStateArr *astate,
415 Datum dvalue, bool disnull,
416 Oid array_type,
417 MemoryContext rcontext);
418 extern Datum makeArrayResultArr(ArrayBuildStateArr *astate,
419 MemoryContext rcontext, bool release);
420
isTriviallyEmpty()421 extern ArrayBuildStateAny *initArrayResultAny(Oid input_type,
422 MemoryContext rcontext, bool subcontext);
423 extern ArrayBuildStateAny *accumArrayResultAny(ArrayBuildStateAny *astate,
424 Datum dvalue, bool disnull,
425 Oid input_type,
426 MemoryContext rcontext);
isSingleStringRef()427 extern Datum makeArrayResultAny(ArrayBuildStateAny *astate,
428 MemoryContext rcontext, bool release);
429
430 extern ArrayIterator array_create_iterator(ArrayType *arr, int slice_ndim, ArrayMetaState *mstate);
431 extern bool array_iterate(ArrayIterator iterator, Datum *value, bool *isnull);
432 extern void array_free_iterator(ArrayIterator iterator);
433
434 /*
435 * prototypes for functions defined in arrayutils.c
436 */
437
438 extern int ArrayGetOffset(int n, const int *dim, const int *lb, const int *indx);
439 extern int ArrayGetOffset0(int n, const int *tup, const int *scale);
440 extern int ArrayGetNItems(int ndim, const int *dims);
441 extern void ArrayCheckBounds(int ndim, const int *dims, const int *lb);
442 extern void mda_get_range(int n, int *span, const int *st, const int *endp);
443 extern void mda_get_prod(int n, const int *range, int *prod);
444 extern void mda_get_offset_values(int n, int *dist, const int *prod, const int *span);
445 extern int mda_next_tuple(int n, int *curr, const int *span);
446 extern int32 *ArrayGetIntegerTypmods(ArrayType *arr, int *n);
447
448 /*
449 * prototypes for functions defined in array_expanded.c
450 */
451 extern Datum expand_array(Datum arraydatum, MemoryContext parentcontext,
452 ArrayMetaState *metacache);
453 extern ExpandedArrayHeader *DatumGetExpandedArray(Datum d);
454 extern ExpandedArrayHeader *DatumGetExpandedArrayX(Datum d,
455 ArrayMetaState *metacache);
456 extern AnyArrayType *DatumGetAnyArrayP(Datum d);
457 extern void deconstruct_expanded_array(ExpandedArrayHeader *eah);
458
getSingleStringRef()459 #endif /* ARRAY_H */
460