/* -------------------------------------------------------------------------
 *
 * array.h
 *	  Declarations for openGauss arrays.
 *
 * A standard varlena array has the following internal structure:
 *	  <vl_len_>		- standard varlena header word
 *	  <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) 1996-2012, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/utils/array.h
 *
 * -------------------------------------------------------------------------
 */
#ifndef ARRAY_H
#define ARRAY_H

#include "fmgr.h"

/*
 * Maximum number of elements in an array. We limit this to at most about a
 * quarter billion elements, so that it's not necessary to check for overflow
 * in quite so many places --- for instance when polloc'ing Datum arrays.
 */
#define MaxArraySize ((Size)(MaxAllocSize) / sizeof(Datum))

/*
 * Arrays are varlena objects, so must meet the varlena convention that
 * the first int32 of the object contains the total object size in bytes.
 * Be sure to use VARSIZE() and SET_VARSIZE() to access it, though!
 *
 * CAUTION: if you change the header for ordinary arrays you will also
 * need to change the headers for oidvector and int2vector!
 */
typedef struct {
    int32 vl_len_;    /* varlena header (do not touch directly!) */
    int ndim;         /* # of dimensions */
    int32 dataoffset; /* offset to data, or 0 if no bitmap */
    Oid elemtype;     /* element type OID */
} ArrayType;

/*
 * working state for accumArrayResult() and friends
 */
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 */
    int alen;               /* allocated length of above arrays */
    int nelems;             /* number of valid entries in above arrays */
    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;

/* ArrayIteratorData is private in arrayfuncs.c */
typedef struct ArrayIteratorData* ArrayIterator;

/*
 * 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) VARSIZE(a)
#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))
/* multiset functions number of args */
#define MULTISET_ARGS_NUM 2
/*
 * 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 hash_array(PG_FUNCTION_ARGS);
extern Datum arrayoverlap(PG_FUNCTION_ARGS);
extern Datum arraycontains(PG_FUNCTION_ARGS);
extern Datum arraycontained(PG_FUNCTION_ARGS);
extern Datum array_ndims(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_extend(PG_FUNCTION_ARGS);
extern Datum array_length(PG_FUNCTION_ARGS);
extern Datum array_exists(PG_FUNCTION_ARGS);
extern Datum array_next(PG_FUNCTION_ARGS);
extern Datum array_varchar_next(PG_FUNCTION_ARGS);
extern Datum array_prior(PG_FUNCTION_ARGS);
extern Datum array_trim(PG_FUNCTION_ARGS);
extern Datum array_delete(PG_FUNCTION_ARGS);
extern Datum array_deleteidx(PG_FUNCTION_ARGS);
extern Datum array_extendnull(PG_FUNCTION_ARGS);
extern Datum array_larger(PG_FUNCTION_ARGS);
extern Datum array_smaller(PG_FUNCTION_ARGS);
extern Datum generate_subscripts(PG_FUNCTION_ARGS);
extern Datum generate_subscripts_nodir(PG_FUNCTION_ARGS);
extern Datum array_fill(PG_FUNCTION_ARGS);
extern Datum array_fill_with_lower_bounds(PG_FUNCTION_ARGS);
extern Datum array_unnest(PG_FUNCTION_ARGS);
extern Datum array_cat_distinct(PG_FUNCTION_ARGS);
extern Datum array_intersect(PG_FUNCTION_ARGS);
extern Datum array_intersect_distinct(PG_FUNCTION_ARGS);
extern Datum array_except(PG_FUNCTION_ARGS);
extern Datum array_except_distinct(PG_FUNCTION_ARGS);

extern Datum array_ref(ArrayType* array, int nSubscripts, const int* indx, int arraytyplen, int elmlen, bool elmbyval,
    char elmalign, bool* isNull);
extern ArrayType* array_set(ArrayType* array, int nSubscripts, const 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 void CopyArrayEls(ArrayType* array, Datum* values, const bool* nulls, int nitems, int typlen, bool typbyval,
    char typalign, bool freedata);

extern ArrayType* construct_array(Datum* elems, int nelems, Oid elmtype, int elmlen, bool elmbyval, char elmalign);
ArrayType* construct_array(Datum* elems, bool * nulls, int nelems, Oid elmtype, int elmlen, bool elmbyval, char elmalign);
extern ArrayType* construct_md_array(Datum* elems, bool* nulls, int ndims, int* dims, const 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 bool array_contains_nulls(ArrayType* array);
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, bool release);

extern ArrayIterator array_create_iterator(ArrayType* arr, int slice_ndim);
extern bool array_iterate(ArrayIterator iterator, Datum* value, bool* isnull);
extern void array_free_iterator(ArrayIterator iterator);

extern int ArrayCastAndSet(Datum src, int typlen, bool typbyval, char typalign, char* dest);

/*
 * 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 ArrayCheckBounds(int ndim, const int *dims, const int *lb);
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);
extern int32* ArrayGetIntegerTypmods(ArrayType* arr, int* n);

/*
 * 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, bool isNull, int ndims);

extern Datum array_agg_transfn(PG_FUNCTION_ARGS);
extern Datum array_agg_finalfn(PG_FUNCTION_ARGS);

/*
 * prototypes for functions defined in array_typanalyze.c
 */
extern Datum array_typanalyze(PG_FUNCTION_ARGS);
extern float8* check_float8_array(ArrayType* transarray, const char* caller, int n);

#endif /* ARRAY_H */