/*------------------------------------------------------------------------- * * array.h * Declarations for Postgres arrays. * * A standard varlena array has the following internal structure: * - total number of bytes (also, TOAST info flags) * - number of dimensions of the array * - offset to stored data, or 0 if no nulls bitmap * - element type OID * - length of each array axis (C array of int) * - lower boundary of each dimension (C array of int) * - bitmap showing locations of nulls (OPTIONAL) * - whatever is the stored data * * The and arrays each have ndim elements. * * The may be omitted if the array contains no NULL elements. * If it is absent, the field is zero and the offset to the * stored data must be computed on-the-fly. If the bitmap is present, * 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) 1996-2006, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * $PostgreSQL: pgsql/src/include/utils/array.h,v 1.59 2006/09/10 20:14:20 tgl Exp $ * *------------------------------------------------------------------------- */ #ifndef ARRAY_H #define ARRAY_H #include "fmgr.h" /* * Arrays are varlena objects, so must meet the varlena convention that * the first int32 of the object contains the total object size in bytes. * * CAUTION: if you change the header for ordinary arrays you will also * need to change the headers for oidvector and int2vector! */ typedef struct { int32 size; /* total array size (varlena requirement) */ int ndim; /* # of dimensions */ int32 dataoffset; /* offset to data, or 0 if no bitmap */ Oid elemtype; /* element type OID */ } ArrayType; 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[] and dnulls[] is always a multiple of * ARRAY_ELEMS_CHUNKSIZE */ #define ARRAY_ELEMS_CHUNKSIZE 64 int nelems; /* number of valid Datums in dvalues[] */ Oid element_type; /* data type of the Datums */ int16 typlen; /* needed info about datatype */ bool typbyval; char typalign; } ArrayBuildState; /* * structure to cache type metadata needed for array manipulation */ typedef struct ArrayMetaState { Oid element_type; int16 typlen; bool typbyval; char typalign; char typdelim; Oid typioparam; Oid typiofunc; FmgrInfo proc; } ArrayMetaState; /* * private state needed by array_map (here because caller must provide it) */ typedef struct ArrayMapState { ArrayMetaState inp_extra; ArrayMetaState ret_extra; } ArrayMapState; /* * fmgr macros for array objects */ #define DatumGetArrayTypeP(X) ((ArrayType *) PG_DETOAST_DATUM(X)) #define DatumGetArrayTypePCopy(X) ((ArrayType *) PG_DETOAST_DATUM_COPY(X)) #define PG_GETARG_ARRAYTYPE_P(n) DatumGetArrayTypeP(PG_GETARG_DATUM(n)) #define PG_GETARG_ARRAYTYPE_P_COPY(n) DatumGetArrayTypePCopy(PG_GETARG_DATUM(n)) #define PG_RETURN_ARRAYTYPE_P(x) PG_RETURN_POINTER(x) /* * Access macros for array header fields. * * ARR_DIMS returns a pointer to an array of array dimensions (number of * elements along the various array axes). * * ARR_LBOUND returns a pointer to an array of array lower bounds. * * That is: if the third axis of an array has elements 5 through 8, then * ARR_DIMS(a)[2] == 4 and ARR_LBOUND(a)[2] == 5. * * Unlike C, the default lower bound is 1. */ #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))) #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 (in bytes) for an array with the specified * number of dimensions and total number of items. */ #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_DATA_OFFSET(a)) /* * GUC parameter */ extern bool Array_nulls; /* * prototypes for functions defined in arrayfuncs.c */ extern Datum array_in(PG_FUNCTION_ARGS); extern Datum array_out(PG_FUNCTION_ARGS); extern Datum array_recv(PG_FUNCTION_ARGS); extern Datum array_send(PG_FUNCTION_ARGS); extern Datum array_eq(PG_FUNCTION_ARGS); extern Datum array_ne(PG_FUNCTION_ARGS); extern Datum array_lt(PG_FUNCTION_ARGS); extern Datum array_gt(PG_FUNCTION_ARGS); extern Datum array_le(PG_FUNCTION_ARGS); extern Datum array_ge(PG_FUNCTION_ARGS); extern Datum btarraycmp(PG_FUNCTION_ARGS); extern Datum arrayoverlap(PG_FUNCTION_ARGS); extern Datum arraycontains(PG_FUNCTION_ARGS); extern Datum arraycontained(PG_FUNCTION_ARGS); extern Datum array_dims(PG_FUNCTION_ARGS); extern Datum array_lower(PG_FUNCTION_ARGS); extern Datum array_upper(PG_FUNCTION_ARGS); extern Datum array_type_coerce(PG_FUNCTION_ARGS); extern Datum array_type_length_coerce(PG_FUNCTION_ARGS); extern Datum array_length_coerce(PG_FUNCTION_ARGS); 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 arraytyplen, int elmlen, bool elmbyval, char elmalign, bool *isNull); extern ArrayType *array_set(ArrayType *array, int nSubscripts, int *indx, 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 arraytyplen, int elmlen, bool elmbyval, char elmalign); extern ArrayType *array_set_slice(ArrayType *array, int nSubscripts, int *upperIndx, int *lowerIndx, 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, bool **nullsp, int *nelemsp); extern ArrayBuildState *accumArrayResult(ArrayBuildState *astate, Datum dvalue, bool disnull, Oid element_type, MemoryContext rcontext); extern Datum makeArrayResult(ArrayBuildState *astate, MemoryContext rcontext); extern Datum makeMdArrayResult(ArrayBuildState *astate, int ndims, int *dims, int *lbs, MemoryContext rcontext); /* * prototypes for functions defined in arrayutils.c */ 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 */ extern Datum array_push(PG_FUNCTION_ARGS); extern Datum array_cat(PG_FUNCTION_ARGS); extern ArrayType *create_singleton_array(FunctionCallInfo fcinfo, Oid element_type, Datum element, int ndims); #endif /* ARRAY_H */