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Make SQL arrays support null elements. This commit fixes the core array
functionality, but I still need to make another pass looking at places that incidentally use arrays (such as ACL manipulation) to make sure they are null-safe. Contrib needs work too. I have not changed the behaviors that are still under discussion about array comparison and what to do with lower bounds.
This commit is contained in:
Tom Lane
@ -1,16 +1,55 @@
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/*-------------------------------------------------------------------------
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*
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* array.h
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* Utilities for the new array code. Contains prototypes from the
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* following files:
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* utils/adt/arrayfuncs.c
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* utils/adt/arrayutils.c
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* Declarations for Postgres arrays.
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*
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* A standard varlena array has the following internal structure:
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* <size> - total number of bytes (also, TOAST info flags)
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* <ndim> - number of dimensions of the array
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* <dataoffset> - offset to stored data, or 0 if no nulls bitmap
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* <elemtype> - element type OID
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* <dimensions> - length of each array axis (C array of int)
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* <lower bnds> - lower boundary of each dimension (C array of int)
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* <null bitmap> - bitmap showing locations of nulls (OPTIONAL)
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* <actual data> - whatever is the stored data
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*
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* The <dimensions> and <lower bnds> arrays each have ndim elements.
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*
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* The <null bitmap> may be omitted if the array contains no NULL elements.
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* If it is absent, the <dataoffset> field is zero and the offset to the
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* stored data must be computed on-the-fly. If the bitmap is present,
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* <dataoffset> is nonzero and is equal to the offset from the array start
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* to the first data element (including any alignment padding). The bitmap
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* follows the same conventions as tuple null bitmaps, ie, a 1 indicates
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* a non-null entry and the LSB of each bitmap byte is used first.
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*
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* The actual data starts on a MAXALIGN boundary. Individual items in the
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* array are aligned as specified by the array element type. They are
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* stored in row-major order (last subscript varies most rapidly).
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*
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* NOTE: it is important that array elements of toastable datatypes NOT be
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* toasted, since the tupletoaster won't know they are there. (We could
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* support compressed toasted items; only out-of-line items are dangerous.
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* However, it seems preferable to store such items uncompressed and allow
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* the toaster to compress the whole array as one input.)
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*
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*
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* The OIDVECTOR and INT2VECTOR datatypes are storage-compatible with
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* generic arrays, but they support only one-dimensional arrays with no
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* nulls (and no null bitmap).
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*
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* There are also some "fixed-length array" datatypes, such as NAME and
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* POINT. These are simply a sequence of a fixed number of items each
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* of a fixed-length datatype, with no overhead; the item size must be
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* a multiple of its alignment requirement, because we do no padding.
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* We support subscripting on these types, but array_in() and array_out()
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* only work with varlena arrays.
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*
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*
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* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* $PostgreSQL: pgsql/src/include/utils/array.h,v 1.55 2005/10/15 02:49:46 momjian Exp $
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* $PostgreSQL: pgsql/src/include/utils/array.h,v 1.56 2005/11/17 22:14:55 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -30,8 +69,7 @@ typedef struct
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{
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int32 size; /* total array size (varlena requirement) */
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int ndim; /* # of dimensions */
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int flags; /* implementation flags */
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/* flags field is currently unused, always zero. */
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int32 dataoffset; /* offset to data, or 0 if no bitmap */
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Oid elemtype; /* element type OID */
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} ArrayType;
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@ -39,9 +77,10 @@ typedef struct ArrayBuildState
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{
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MemoryContext mcontext; /* where all the temp stuff is kept */
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Datum *dvalues; /* array of accumulated Datums */
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bool *dnulls; /* array of is-null flags for Datums */
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/*
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* The allocated size of dvalues[] is always a multiple of
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* The allocated size of dvalues[] and dnulls[] is always a multiple of
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* ARRAY_ELEMS_CHUNKSIZE
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*/
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#define ARRAY_ELEMS_CHUNKSIZE 64
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@ -98,29 +137,48 @@ typedef struct ArrayMapState
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*
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* Unlike C, the default lower bound is 1.
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*/
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#define ARR_SIZE(a) (((ArrayType *) (a))->size)
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#define ARR_NDIM(a) (((ArrayType *) (a))->ndim)
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#define ARR_ELEMTYPE(a) (((ArrayType *) (a))->elemtype)
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#define ARR_SIZE(a) ((a)->size)
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#define ARR_NDIM(a) ((a)->ndim)
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#define ARR_HASNULL(a) ((a)->dataoffset != 0)
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#define ARR_ELEMTYPE(a) ((a)->elemtype)
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#define ARR_DIMS(a) \
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((int *) (((char *) (a)) + sizeof(ArrayType)))
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#define ARR_LBOUND(a) \
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((int *) (((char *) (a)) + sizeof(ArrayType) + \
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(sizeof(int) * ARR_NDIM(a))))
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sizeof(int) * ARR_NDIM(a)))
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#define ARR_NULLBITMAP(a) \
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(ARR_HASNULL(a) ? \
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(bits8 *) (((char *) (a)) + sizeof(ArrayType) + \
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2 * sizeof(int) * ARR_NDIM(a)) \
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: (bits8 *) NULL)
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/*
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* The total array header size for an array of dimension n (in bytes).
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* The total array header size (in bytes) for an array with the specified
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* number of dimensions and total number of items.
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*/
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#define ARR_OVERHEAD(n) \
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(MAXALIGN(sizeof(ArrayType) + 2 * sizeof(int) * (n)))
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#define ARR_OVERHEAD_NONULLS(ndims) \
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MAXALIGN(sizeof(ArrayType) + 2 * sizeof(int) * (ndims))
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#define ARR_OVERHEAD_WITHNULLS(ndims, nitems) \
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MAXALIGN(sizeof(ArrayType) + 2 * sizeof(int) * (ndims) + \
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((nitems) + 7) / 8)
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#define ARR_DATA_OFFSET(a) \
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(ARR_HASNULL(a) ? (a)->dataoffset : ARR_OVERHEAD_NONULLS(ARR_NDIM(a)))
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/*
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* Returns a pointer to the actual array data.
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*/
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#define ARR_DATA_PTR(a) \
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(((char *) (a)) + ARR_OVERHEAD(ARR_NDIM(a)))
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(((char *) (a)) + ARR_DATA_OFFSET(a))
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/*
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* GUC parameter
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*/
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extern bool Array_nulls;
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/*
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* prototypes for functions defined in arrayfuncs.c
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*/
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@ -145,37 +203,40 @@ extern Datum array_larger(PG_FUNCTION_ARGS);
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extern Datum array_smaller(PG_FUNCTION_ARGS);
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extern Datum array_ref(ArrayType *array, int nSubscripts, int *indx,
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int arraylen, int elmlen, bool elmbyval, char elmalign,
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int arraytyplen, int elmlen, bool elmbyval, char elmalign,
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bool *isNull);
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extern ArrayType *array_set(ArrayType *array, int nSubscripts, int *indx,
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Datum dataValue,
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int arraylen, int elmlen, bool elmbyval, char elmalign,
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bool *isNull);
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Datum dataValue, bool isNull,
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int arraytyplen, int elmlen, bool elmbyval, char elmalign);
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extern ArrayType *array_get_slice(ArrayType *array, int nSubscripts,
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int *upperIndx, int *lowerIndx,
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int arraylen, int elmlen, bool elmbyval, char elmalign,
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bool *isNull);
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int arraytyplen, int elmlen, bool elmbyval, char elmalign);
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extern ArrayType *array_set_slice(ArrayType *array, int nSubscripts,
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int *upperIndx, int *lowerIndx,
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ArrayType *srcArray,
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int arraylen, int elmlen, bool elmbyval, char elmalign,
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bool *isNull);
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ArrayType *srcArray, bool isNull,
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int arraytyplen, int elmlen, bool elmbyval, char elmalign);
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extern Datum array_map(FunctionCallInfo fcinfo, Oid inpType, Oid retType,
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ArrayMapState *amstate);
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extern void array_bitmap_copy(bits8 *destbitmap, int destoffset,
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const bits8 *srcbitmap, int srcoffset,
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int nitems);
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extern ArrayType *construct_array(Datum *elems, int nelems,
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Oid elmtype,
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int elmlen, bool elmbyval, char elmalign);
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extern ArrayType *construct_md_array(Datum *elems,
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bool *nulls,
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int ndims,
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int *dims,
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int *lbs,
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Oid elmtype, int elmlen, bool elmbyval, char elmalign);
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extern ArrayType *construct_empty_array(Oid elmtype);
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extern void deconstruct_array(ArrayType *array,
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Oid elmtype,
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int elmlen, bool elmbyval, char elmalign,
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Datum **elemsp, int *nelemsp);
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Datum **elemsp, bool **nullsp, int *nelemsp);
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extern ArrayBuildState *accumArrayResult(ArrayBuildState *astate,
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Datum dvalue, bool disnull,
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Oid element_type,
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@ -189,13 +250,13 @@ extern Datum makeMdArrayResult(ArrayBuildState *astate, int ndims,
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* prototypes for functions defined in arrayutils.c
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*/
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extern int ArrayGetOffset(int n, int *dim, int *lb, int *indx);
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extern int ArrayGetOffset0(int n, int *tup, int *scale);
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extern int ArrayGetNItems(int ndims, int *dims);
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extern void mda_get_range(int n, int *span, int *st, int *endp);
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extern void mda_get_prod(int n, int *range, int *prod);
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extern void mda_get_offset_values(int n, int *dist, int *prod, int *span);
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extern int mda_next_tuple(int n, int *curr, int *span);
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extern int ArrayGetOffset(int n, const int *dim, const int *lb, const int *indx);
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extern int ArrayGetOffset0(int n, const int *tup, const int *scale);
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extern int ArrayGetNItems(int ndim, const int *dims);
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extern void mda_get_range(int n, int *span, const int *st, const int *endp);
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extern void mda_get_prod(int n, const int *range, int *prod);
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extern void mda_get_offset_values(int n, int *dist, const int *prod, const int *span);
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extern int mda_next_tuple(int n, int *curr, const int *span);
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/*
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* prototypes for functions defined in array_userfuncs.c
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