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-rw-r--r--src/include/utils/array.h127
1 files changed, 94 insertions, 33 deletions
diff --git a/src/include/utils/array.h b/src/include/utils/array.h
index 1e8be026063..d3653cff0d8 100644
--- a/src/include/utils/array.h
+++ b/src/include/utils/array.h
@@ -1,16 +1,55 @@
/*-------------------------------------------------------------------------
*
* array.h
- * Utilities for the new array code. Contains prototypes from the
- * following files:
- * utils/adt/arrayfuncs.c
- * utils/adt/arrayutils.c
+ * Declarations for Postgres arrays.
+ *
+ * A standard varlena array has the following internal structure:
+ * <size> - total number of bytes (also, TOAST info flags)
+ * <ndim> - number of dimensions of the array
+ * <dataoffset> - offset to stored data, or 0 if no nulls bitmap
+ * <elemtype> - element type OID
+ * <dimensions> - length of each array axis (C array of int)
+ * <lower bnds> - lower boundary of each dimension (C array of int)
+ * <null bitmap> - bitmap showing locations of nulls (OPTIONAL)
+ * <actual data> - whatever is the stored data
+ *
+ * The <dimensions> and <lower bnds> arrays each have ndim elements.
+ *
+ * The <null bitmap> may be omitted if the array contains no NULL elements.
+ * If it is absent, the <dataoffset> field is zero and the offset to the
+ * stored data must be computed on-the-fly. If the bitmap is present,
+ * <dataoffset> is nonzero and is equal to the offset from the array start
+ * to the first data element (including any alignment padding). The bitmap
+ * follows the same conventions as tuple null bitmaps, ie, a 1 indicates
+ * a non-null entry and the LSB of each bitmap byte is used first.
+ *
+ * The actual data starts on a MAXALIGN boundary. Individual items in the
+ * array are aligned as specified by the array element type. They are
+ * stored in row-major order (last subscript varies most rapidly).
+ *
+ * NOTE: it is important that array elements of toastable datatypes NOT be
+ * toasted, since the tupletoaster won't know they are there. (We could
+ * support compressed toasted items; only out-of-line items are dangerous.
+ * However, it seems preferable to store such items uncompressed and allow
+ * the toaster to compress the whole array as one input.)
+ *
+ *
+ * The OIDVECTOR and INT2VECTOR datatypes are storage-compatible with
+ * generic arrays, but they support only one-dimensional arrays with no
+ * nulls (and no null bitmap).
+ *
+ * There are also some "fixed-length array" datatypes, such as NAME and
+ * POINT. These are simply a sequence of a fixed number of items each
+ * of a fixed-length datatype, with no overhead; the item size must be
+ * a multiple of its alignment requirement, because we do no padding.
+ * We support subscripting on these types, but array_in() and array_out()
+ * only work with varlena arrays.
*
*
* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/utils/array.h,v 1.55 2005/10/15 02:49:46 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/utils/array.h,v 1.56 2005/11/17 22:14:55 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -30,8 +69,7 @@ typedef struct
{
int32 size; /* total array size (varlena requirement) */
int ndim; /* # of dimensions */
- int flags; /* implementation flags */
- /* flags field is currently unused, always zero. */
+ int32 dataoffset; /* offset to data, or 0 if no bitmap */
Oid elemtype; /* element type OID */
} ArrayType;
@@ -39,9 +77,10 @@ typedef struct ArrayBuildState
{
MemoryContext mcontext; /* where all the temp stuff is kept */
Datum *dvalues; /* array of accumulated Datums */
+ bool *dnulls; /* array of is-null flags for Datums */
/*
- * The allocated size of dvalues[] is always a multiple of
+ * The allocated size of dvalues[] and dnulls[] is always a multiple of
* ARRAY_ELEMS_CHUNKSIZE
*/
#define ARRAY_ELEMS_CHUNKSIZE 64
@@ -98,30 +137,49 @@ typedef struct ArrayMapState
*
* Unlike C, the default lower bound is 1.
*/
-#define ARR_SIZE(a) (((ArrayType *) (a))->size)
-#define ARR_NDIM(a) (((ArrayType *) (a))->ndim)
-#define ARR_ELEMTYPE(a) (((ArrayType *) (a))->elemtype)
+#define ARR_SIZE(a) ((a)->size)
+#define ARR_NDIM(a) ((a)->ndim)
+#define ARR_HASNULL(a) ((a)->dataoffset != 0)
+#define ARR_ELEMTYPE(a) ((a)->elemtype)
#define ARR_DIMS(a) \
((int *) (((char *) (a)) + sizeof(ArrayType)))
#define ARR_LBOUND(a) \
((int *) (((char *) (a)) + sizeof(ArrayType) + \
- (sizeof(int) * ARR_NDIM(a))))
+ sizeof(int) * ARR_NDIM(a)))
+
+#define ARR_NULLBITMAP(a) \
+ (ARR_HASNULL(a) ? \
+ (bits8 *) (((char *) (a)) + sizeof(ArrayType) + \
+ 2 * sizeof(int) * ARR_NDIM(a)) \
+ : (bits8 *) NULL)
/*
- * The total array header size for an array of dimension n (in bytes).
+ * The total array header size (in bytes) for an array with the specified
+ * number of dimensions and total number of items.
*/
-#define ARR_OVERHEAD(n) \
- (MAXALIGN(sizeof(ArrayType) + 2 * sizeof(int) * (n)))
+#define ARR_OVERHEAD_NONULLS(ndims) \
+ MAXALIGN(sizeof(ArrayType) + 2 * sizeof(int) * (ndims))
+#define ARR_OVERHEAD_WITHNULLS(ndims, nitems) \
+ MAXALIGN(sizeof(ArrayType) + 2 * sizeof(int) * (ndims) + \
+ ((nitems) + 7) / 8)
+
+#define ARR_DATA_OFFSET(a) \
+ (ARR_HASNULL(a) ? (a)->dataoffset : ARR_OVERHEAD_NONULLS(ARR_NDIM(a)))
/*
* Returns a pointer to the actual array data.
*/
#define ARR_DATA_PTR(a) \
- (((char *) (a)) + ARR_OVERHEAD(ARR_NDIM(a)))
+ (((char *) (a)) + ARR_DATA_OFFSET(a))
/*
+ * GUC parameter
+ */
+extern bool Array_nulls;
+
+/*
* prototypes for functions defined in arrayfuncs.c
*/
extern Datum array_in(PG_FUNCTION_ARGS);
@@ -145,37 +203,40 @@ extern Datum array_larger(PG_FUNCTION_ARGS);
extern Datum array_smaller(PG_FUNCTION_ARGS);
extern Datum array_ref(ArrayType *array, int nSubscripts, int *indx,
- int arraylen, int elmlen, bool elmbyval, char elmalign,
+ int arraytyplen, int elmlen, bool elmbyval, char elmalign,
bool *isNull);
extern ArrayType *array_set(ArrayType *array, int nSubscripts, int *indx,
- Datum dataValue,
- int arraylen, int elmlen, bool elmbyval, char elmalign,
- bool *isNull);
+ Datum dataValue, bool isNull,
+ int arraytyplen, int elmlen, bool elmbyval, char elmalign);
extern ArrayType *array_get_slice(ArrayType *array, int nSubscripts,
int *upperIndx, int *lowerIndx,
- int arraylen, int elmlen, bool elmbyval, char elmalign,
- bool *isNull);
+ int arraytyplen, int elmlen, bool elmbyval, char elmalign);
extern ArrayType *array_set_slice(ArrayType *array, int nSubscripts,
int *upperIndx, int *lowerIndx,
- ArrayType *srcArray,
- int arraylen, int elmlen, bool elmbyval, char elmalign,
- bool *isNull);
+ ArrayType *srcArray, bool isNull,
+ int arraytyplen, int elmlen, bool elmbyval, char elmalign);
extern Datum array_map(FunctionCallInfo fcinfo, Oid inpType, Oid retType,
ArrayMapState *amstate);
+extern void array_bitmap_copy(bits8 *destbitmap, int destoffset,
+ const bits8 *srcbitmap, int srcoffset,
+ int nitems);
+
extern ArrayType *construct_array(Datum *elems, int nelems,
Oid elmtype,
int elmlen, bool elmbyval, char elmalign);
extern ArrayType *construct_md_array(Datum *elems,
+ bool *nulls,
int ndims,
int *dims,
int *lbs,
Oid elmtype, int elmlen, bool elmbyval, char elmalign);
+extern ArrayType *construct_empty_array(Oid elmtype);
extern void deconstruct_array(ArrayType *array,
Oid elmtype,
int elmlen, bool elmbyval, char elmalign,
- Datum **elemsp, int *nelemsp);
+ Datum **elemsp, bool **nullsp, int *nelemsp);
extern ArrayBuildState *accumArrayResult(ArrayBuildState *astate,
Datum dvalue, bool disnull,
Oid element_type,
@@ -189,13 +250,13 @@ extern Datum makeMdArrayResult(ArrayBuildState *astate, int ndims,
* prototypes for functions defined in arrayutils.c
*/
-extern int ArrayGetOffset(int n, int *dim, int *lb, int *indx);
-extern int ArrayGetOffset0(int n, int *tup, int *scale);
-extern int ArrayGetNItems(int ndims, int *dims);
-extern void mda_get_range(int n, int *span, int *st, int *endp);
-extern void mda_get_prod(int n, int *range, int *prod);
-extern void mda_get_offset_values(int n, int *dist, int *prod, int *span);
-extern int mda_next_tuple(int n, int *curr, int *span);
+extern int ArrayGetOffset(int n, const int *dim, const int *lb, const int *indx);
+extern int ArrayGetOffset0(int n, const int *tup, const int *scale);
+extern int ArrayGetNItems(int ndim, const int *dims);
+extern void mda_get_range(int n, int *span, const int *st, const int *endp);
+extern void mda_get_prod(int n, const int *range, int *prod);
+extern void mda_get_offset_values(int n, int *dist, const int *prod, const int *span);
+extern int mda_next_tuple(int n, int *curr, const int *span);
/*
* prototypes for functions defined in array_userfuncs.c
generated by cgit v1.2.3 (git 2.25.1) at 2025-06-02 13:03:09 +0000