array_userfuncs.c File Reference

#include "postgres.h"
#include "catalog/pg_operator_d.h"
#include "catalog/pg_type.h"
#include "common/int.h"
#include "common/pg_prng.h"
#include "libpq/pqformat.h"
#include "miscadmin.h"
#include "nodes/supportnodes.h"
#include "port/pg_bitutils.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/datum.h"
#include "utils/lsyscache.h"
#include "utils/tuplesort.h"
#include "utils/typcache.h"

Include dependency graph for array_userfuncs.c:

Go to the source code of this file.

Data Structures
struct	SerialIOData
struct	DeserialIOData
struct	ArraySortCachedInfo

Typedefs
typedef struct SerialIOData	SerialIOData
typedef struct DeserialIOData	DeserialIOData
typedef struct ArraySortCachedInfo	ArraySortCachedInfo

Functions
static Datum	array_position_common (FunctionCallInfo fcinfo)
static ExpandedArrayHeader *	fetch_array_arg_replace_nulls (FunctionCallInfo fcinfo, int argno)
Datum	array_append (PG_FUNCTION_ARGS)
Datum	array_append_support (PG_FUNCTION_ARGS)
Datum	array_prepend (PG_FUNCTION_ARGS)
Datum	array_prepend_support (PG_FUNCTION_ARGS)
Datum	array_cat (PG_FUNCTION_ARGS)
Datum	array_agg_transfn (PG_FUNCTION_ARGS)
Datum	array_agg_combine (PG_FUNCTION_ARGS)
Datum	array_agg_serialize (PG_FUNCTION_ARGS)
Datum	array_agg_deserialize (PG_FUNCTION_ARGS)
Datum	array_agg_finalfn (PG_FUNCTION_ARGS)
Datum	array_agg_array_transfn (PG_FUNCTION_ARGS)
Datum	array_agg_array_combine (PG_FUNCTION_ARGS)
Datum	array_agg_array_serialize (PG_FUNCTION_ARGS)
Datum	array_agg_array_deserialize (PG_FUNCTION_ARGS)
Datum	array_agg_array_finalfn (PG_FUNCTION_ARGS)
Datum	array_position (PG_FUNCTION_ARGS)
Datum	array_position_start (PG_FUNCTION_ARGS)
Datum	array_positions (PG_FUNCTION_ARGS)
static ArrayType *	array_shuffle_n (ArrayType *array, int n, bool keep_lb, Oid elmtyp, TypeCacheEntry *typentry)
Datum	array_shuffle (PG_FUNCTION_ARGS)
Datum	array_sample (PG_FUNCTION_ARGS)
static ArrayType *	array_reverse_n (ArrayType *array, Oid elmtyp, TypeCacheEntry *typentry)
Datum	array_reverse (PG_FUNCTION_ARGS)
static ArrayType *	array_sort_internal (ArrayType *array, bool descending, bool nulls_first, FunctionCallInfo fcinfo)
Datum	array_sort (PG_FUNCTION_ARGS)
Datum	array_sort_order (PG_FUNCTION_ARGS)
Datum	array_sort_order_nulls_first (PG_FUNCTION_ARGS)

Typedef Documentation

ArraySortCachedInfo

typedef struct ArraySortCachedInfo ArraySortCachedInfo

DeserialIOData

typedef struct DeserialIOData DeserialIOData

SerialIOData

typedef struct SerialIOData SerialIOData

Function Documentation

array_agg_array_combine()

Datum array_agg_array_combine

(

PG_FUNCTION_ARGS

)

Definition at line 977 of file array_userfuncs.c.

{
    ArrayBuildStateArr *state1;
    ArrayBuildStateArr *state2;
    MemoryContext agg_context;
    MemoryContext old_context;
 
    if (!AggCheckCallContext(fcinfo, &agg_context))
        elog(ERROR, "aggregate function called in non-aggregate context");
 
    state1 = PG_ARGISNULL(0) ? NULL : (ArrayBuildStateArr *) PG_GETARG_POINTER(0);
    state2 = PG_ARGISNULL(1) ? NULL : (ArrayBuildStateArr *) PG_GETARG_POINTER(1);
 
    if (state2 == NULL)
    {
        /*
         * NULL state2 is easy, just return state1, which we know is already
         * in the agg_context
         */
        if (state1 == NULL)
            PG_RETURN_NULL();
        PG_RETURN_POINTER(state1);
    }
 
    if (state1 == NULL)
    {
        /* We must copy state2's data into the agg_context */
        old_context = MemoryContextSwitchTo(agg_context);
 
        state1 = initArrayResultArr(state2->array_type, InvalidOid,
                                    agg_context, false);
 
        state1->abytes = state2->abytes;
        state1->data = (char *) palloc(state1->abytes);
 
        if (state2->nullbitmap)
        {
            int         size = (state2->aitems + 7) / 8;
 
            state1->nullbitmap = (bits8 *) palloc(size);
            memcpy(state1->nullbitmap, state2->nullbitmap, size);
        }
 
        memcpy(state1->data, state2->data, state2->nbytes);
        state1->nbytes = state2->nbytes;
        state1->aitems = state2->aitems;
        state1->nitems = state2->nitems;
        state1->ndims = state2->ndims;
        memcpy(state1->dims, state2->dims, sizeof(state2->dims));
        memcpy(state1->lbs, state2->lbs, sizeof(state2->lbs));
        state1->array_type = state2->array_type;
        state1->element_type = state2->element_type;
 
        MemoryContextSwitchTo(old_context);
 
        PG_RETURN_POINTER(state1);
    }
 
    /* We only need to combine the two states if state2 has any items */
    else if (state2->nitems > 0)
    {
        MemoryContext oldContext;
        int         reqsize = state1->nbytes + state2->nbytes;
        int         i;
 
        /*
         * Check the states are compatible with each other.  Ensure we use the
         * same error messages that are listed in accumArrayResultArr so that
         * the same error is shown as would have been if we'd not used the
         * combine function for the aggregation.
         */
        if (state1->ndims != state2->ndims)
            ereport(ERROR,
                    (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
                     errmsg("cannot accumulate arrays of different dimensionality")));
 
        /* Check dimensions match ignoring the first dimension. */
        for (i = 1; i < state1->ndims; i++)
        {
            if (state1->dims[i] != state2->dims[i] || state1->lbs[i] != state2->lbs[i])
                ereport(ERROR,
                        (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
                         errmsg("cannot accumulate arrays of different dimensionality")));
        }
 
 
        oldContext = MemoryContextSwitchTo(state1->mcontext);
 
        /*
         * If there's not enough space in state1 then we'll need to reallocate
         * more.
         */
        if (state1->abytes < reqsize)
        {
            /* use a power of 2 size rather than allocating just reqsize */
            state1->abytes = pg_nextpower2_32(reqsize);
            state1->data = (char *) repalloc(state1->data, state1->abytes);
        }
 
        if (state2->nullbitmap)
        {
            int         newnitems = state1->nitems + state2->nitems;
 
            if (state1->nullbitmap == NULL)
            {
                /*
                 * First input with nulls; we must retrospectively handle any
                 * previous inputs by marking all their items non-null.
                 */
                state1->aitems = pg_nextpower2_32(Max(256, newnitems + 1));
                state1->nullbitmap = (bits8 *) palloc((state1->aitems + 7) / 8);
                array_bitmap_copy(state1->nullbitmap, 0,
                                  NULL, 0,
                                  state1->nitems);
            }
            else if (newnitems > state1->aitems)
            {
                int         newaitems = state1->aitems + state2->aitems;
 
                state1->aitems = pg_nextpower2_32(newaitems);
                state1->nullbitmap = (bits8 *)
                    repalloc(state1->nullbitmap, (state1->aitems + 7) / 8);
            }
            array_bitmap_copy(state1->nullbitmap, state1->nitems,
                              state2->nullbitmap, 0,
                              state2->nitems);
        }
 
        memcpy(state1->data + state1->nbytes, state2->data, state2->nbytes);
        state1->nbytes += state2->nbytes;
        state1->nitems += state2->nitems;
 
        state1->dims[0] += state2->dims[0];
        /* remaining dims already match, per test above */
 
        Assert(state1->array_type == state2->array_type);
        Assert(state1->element_type == state2->element_type);
 
        MemoryContextSwitchTo(oldContext);
    }
 
    PG_RETURN_POINTER(state1);
}

References AggCheckCallContext(), array_bitmap_copy(), Assert, elog, ereport, errcode(), errmsg(), ERROR, fb(), i, initArrayResultArr(), InvalidOid, Max, MemoryContextSwitchTo(), palloc(), PG_ARGISNULL, PG_GETARG_POINTER, pg_nextpower2_32(), PG_RETURN_NULL, PG_RETURN_POINTER, and repalloc().

array_agg_array_deserialize()

Datum array_agg_array_deserialize

(

PG_FUNCTION_ARGS

)

Definition at line 1185 of file array_userfuncs.c.

{
    bytea      *sstate;
    ArrayBuildStateArr *result;
    StringInfoData buf;
    Oid         element_type;
    Oid         array_type;
    int         nbytes;
    const char *temp;
 
    /* cannot be called directly because of internal-type argument */
    Assert(AggCheckCallContext(fcinfo, NULL));
 
    sstate = PG_GETARG_BYTEA_PP(0);
 
    /*
     * Initialize a StringInfo so that we can "receive" it using the standard
     * recv-function infrastructure.
     */
    initReadOnlyStringInfo(&buf, VARDATA_ANY(sstate),
                           VARSIZE_ANY_EXHDR(sstate));
 
    /* element_type */
    element_type = pq_getmsgint(&buf, 4);
 
    /* array_type */
    array_type = pq_getmsgint(&buf, 4);
 
    /* nbytes */
    nbytes = pq_getmsgint(&buf, 4);
 
    result = initArrayResultArr(array_type, element_type,
                                CurrentMemoryContext, false);
 
    result->abytes = 1024;
    while (result->abytes < nbytes)
        result->abytes *= 2;
 
    result->data = (char *) palloc(result->abytes);
 
    /* data */
    temp = pq_getmsgbytes(&buf, nbytes);
    memcpy(result->data, temp, nbytes);
    result->nbytes = nbytes;
 
    /* abytes */
    result->abytes = pq_getmsgint(&buf, 4);
 
    /* aitems: might be 0 */
    result->aitems = pq_getmsgint(&buf, 4);
 
    /* nullbitmap */
    if (result->aitems > 0)
    {
        int         size = (result->aitems + 7) / 8;
 
        result->nullbitmap = (bits8 *) palloc(size);
        temp = pq_getmsgbytes(&buf, size);
        memcpy(result->nullbitmap, temp, size);
    }
    else
        result->nullbitmap = NULL;
 
    /* nitems */
    result->nitems = pq_getmsgint(&buf, 4);
 
    /* ndims */
    result->ndims = pq_getmsgint(&buf, 4);
 
    /* dims */
    temp = pq_getmsgbytes(&buf, sizeof(result->dims));
    memcpy(result->dims, temp, sizeof(result->dims));
 
    /* lbs */
    temp = pq_getmsgbytes(&buf, sizeof(result->lbs));
    memcpy(result->lbs, temp, sizeof(result->lbs));
 
    pq_getmsgend(&buf);
 
    PG_RETURN_POINTER(result);
}

References ArrayBuildStateArr::abytes, AggCheckCallContext(), ArrayBuildStateArr::aitems, Assert, buf, CurrentMemoryContext, ArrayBuildStateArr::data, ArrayBuildStateArr::dims, fb(), initArrayResultArr(), initReadOnlyStringInfo(), ArrayBuildStateArr::lbs, ArrayBuildStateArr::nbytes, ArrayBuildStateArr::ndims, ArrayBuildStateArr::nitems, ArrayBuildStateArr::nullbitmap, palloc(), PG_GETARG_BYTEA_PP, PG_RETURN_POINTER, pq_getmsgbytes(), pq_getmsgend(), pq_getmsgint(), VARDATA_ANY(), and VARSIZE_ANY_EXHDR().

array_agg_array_finalfn()

Datum array_agg_array_finalfn

(

PG_FUNCTION_ARGS

)

Definition at line 1268 of file array_userfuncs.c.

{
    Datum       result;
    ArrayBuildStateArr *state;
 
    /* cannot be called directly because of internal-type argument */
    Assert(AggCheckCallContext(fcinfo, NULL));
 
    state = PG_ARGISNULL(0) ? NULL : (ArrayBuildStateArr *) PG_GETARG_POINTER(0);
 
    if (state == NULL)
        PG_RETURN_NULL();       /* returns null iff no input values */
 
    /*
     * Make the result.  We cannot release the ArrayBuildStateArr because
     * sometimes aggregate final functions are re-executed.  Rather, it is
     * nodeAgg.c's responsibility to reset the aggcontext when it's safe to do
     * so.
     */
    result = makeArrayResultArr(state, CurrentMemoryContext, false);
 
    PG_RETURN_DATUM(result);
}

References AggCheckCallContext(), Assert, CurrentMemoryContext, fb(), makeArrayResultArr(), PG_ARGISNULL, PG_GETARG_POINTER, PG_RETURN_DATUM, and PG_RETURN_NULL.

array_agg_array_serialize()

Datum array_agg_array_serialize

(

PG_FUNCTION_ARGS

)

Definition at line 1126 of file array_userfuncs.c.

{
    ArrayBuildStateArr *state;
    StringInfoData buf;
    bytea      *result;
 
    /* cannot be called directly because of internal-type argument */
    Assert(AggCheckCallContext(fcinfo, NULL));
 
    state = (ArrayBuildStateArr *) PG_GETARG_POINTER(0);
 
    pq_begintypsend(&buf);
 
    /*
     * element_type. Putting this first is more convenient in deserialization
     * so that we can init the new state sooner.
     */
    pq_sendint32(&buf, state->element_type);
 
    /* array_type */
    pq_sendint32(&buf, state->array_type);
 
    /* nbytes */
    pq_sendint32(&buf, state->nbytes);
 
    /* data */
    pq_sendbytes(&buf, state->data, state->nbytes);
 
    /* abytes */
    pq_sendint32(&buf, state->abytes);
 
    /* aitems */
    pq_sendint32(&buf, state->aitems);
 
    /* nullbitmap */
    if (state->nullbitmap)
    {
        Assert(state->aitems > 0);
        pq_sendbytes(&buf, state->nullbitmap, (state->aitems + 7) / 8);
    }
 
    /* nitems */
    pq_sendint32(&buf, state->nitems);
 
    /* ndims */
    pq_sendint32(&buf, state->ndims);
 
    /* dims: XXX should we just send ndims elements? */
    pq_sendbytes(&buf, state->dims, sizeof(state->dims));
 
    /* lbs */
    pq_sendbytes(&buf, state->lbs, sizeof(state->lbs));
 
    result = pq_endtypsend(&buf);
 
    PG_RETURN_BYTEA_P(result);
}

References AggCheckCallContext(), Assert, buf, fb(), PG_GETARG_POINTER, PG_RETURN_BYTEA_P, pq_begintypsend(), pq_endtypsend(), pq_sendbytes(), and pq_sendint32().

array_agg_array_transfn()

Datum array_agg_array_transfn

(

PG_FUNCTION_ARGS

)

Definition at line 933 of file array_userfuncs.c.

{
    Oid         arg1_typeid = get_fn_expr_argtype(fcinfo->flinfo, 1);
    MemoryContext aggcontext;
    ArrayBuildStateArr *state;
 
    if (arg1_typeid == InvalidOid)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("could not determine input data type")));
 
    /*
     * Note: we do not need a run-time check about whether arg1_typeid is a
     * valid array type, because the parser would have verified that while
     * resolving the input/result types of this polymorphic aggregate.
     */
 
    if (!AggCheckCallContext(fcinfo, &aggcontext))
    {
        /* cannot be called directly because of internal-type argument */
        elog(ERROR, "array_agg_array_transfn called in non-aggregate context");
    }
 
 
    if (PG_ARGISNULL(0))
        state = initArrayResultArr(arg1_typeid, InvalidOid, aggcontext, false);
    else
        state = (ArrayBuildStateArr *) PG_GETARG_POINTER(0);
 
    state = accumArrayResultArr(state,
                                PG_GETARG_DATUM(1),
                                PG_ARGISNULL(1),
                                arg1_typeid,
                                aggcontext);
 
    /*
     * The transition type for array_agg() is declared to be "internal", which
     * is a pass-by-value type the same size as a pointer.  So we can safely
     * pass the ArrayBuildStateArr pointer through nodeAgg.c's machinations.
     */
    PG_RETURN_POINTER(state);
}

References accumArrayResultArr(), AggCheckCallContext(), elog, ereport, errcode(), errmsg(), ERROR, fb(), get_fn_expr_argtype(), initArrayResultArr(), InvalidOid, PG_ARGISNULL, PG_GETARG_DATUM, PG_GETARG_POINTER, and PG_RETURN_POINTER.

array_agg_combine()

Datum array_agg_combine

(

PG_FUNCTION_ARGS

)

Definition at line 601 of file array_userfuncs.c.

{
    ArrayBuildState *state1;
    ArrayBuildState *state2;
    MemoryContext agg_context;
    MemoryContext old_context;
 
    if (!AggCheckCallContext(fcinfo, &agg_context))
        elog(ERROR, "aggregate function called in non-aggregate context");
 
    state1 = PG_ARGISNULL(0) ? NULL : (ArrayBuildState *) PG_GETARG_POINTER(0);
    state2 = PG_ARGISNULL(1) ? NULL : (ArrayBuildState *) PG_GETARG_POINTER(1);
 
    if (state2 == NULL)
    {
        /*
         * NULL state2 is easy, just return state1, which we know is already
         * in the agg_context
         */
        if (state1 == NULL)
            PG_RETURN_NULL();
        PG_RETURN_POINTER(state1);
    }
 
    if (state1 == NULL)
    {
        /* We must copy state2's data into the agg_context */
        state1 = initArrayResultWithSize(state2->element_type, agg_context,
                                         false, state2->alen);
 
        old_context = MemoryContextSwitchTo(agg_context);
 
        for (int i = 0; i < state2->nelems; i++)
        {
            if (!state2->dnulls[i])
                state1->dvalues[i] = datumCopy(state2->dvalues[i],
                                               state1->typbyval,
                                               state1->typlen);
            else
                state1->dvalues[i] = (Datum) 0;
        }
 
        MemoryContextSwitchTo(old_context);
 
        memcpy(state1->dnulls, state2->dnulls, sizeof(bool) * state2->nelems);
 
        state1->nelems = state2->nelems;
 
        PG_RETURN_POINTER(state1);
    }
    else if (state2->nelems > 0)
    {
        /* We only need to combine the two states if state2 has any elements */
        int         reqsize = state1->nelems + state2->nelems;
        MemoryContext oldContext = MemoryContextSwitchTo(state1->mcontext);
 
        Assert(state1->element_type == state2->element_type);
 
        /* Enlarge state1 arrays if needed */
        if (state1->alen < reqsize)
        {
            /* Use a power of 2 size rather than allocating just reqsize */
            state1->alen = pg_nextpower2_32(reqsize);
            state1->dvalues = (Datum *) repalloc(state1->dvalues,
                                                 state1->alen * sizeof(Datum));
            state1->dnulls = (bool *) repalloc(state1->dnulls,
                                               state1->alen * sizeof(bool));
        }
 
        /* Copy in the state2 elements to the end of the state1 arrays */
        for (int i = 0; i < state2->nelems; i++)
        {
            if (!state2->dnulls[i])
                state1->dvalues[i + state1->nelems] =
                    datumCopy(state2->dvalues[i],
                              state1->typbyval,
                              state1->typlen);
            else
                state1->dvalues[i + state1->nelems] = (Datum) 0;
        }
 
        memcpy(&state1->dnulls[state1->nelems], state2->dnulls,
               sizeof(bool) * state2->nelems);
 
        state1->nelems = reqsize;
 
        MemoryContextSwitchTo(oldContext);
    }
 
    PG_RETURN_POINTER(state1);
}

References AggCheckCallContext(), Assert, datumCopy(), elog, ERROR, fb(), i, initArrayResultWithSize(), MemoryContextSwitchTo(), PG_ARGISNULL, PG_GETARG_POINTER, pg_nextpower2_32(), PG_RETURN_NULL, PG_RETURN_POINTER, and repalloc().

array_agg_deserialize()

Datum array_agg_deserialize

(

PG_FUNCTION_ARGS

)

Definition at line 787 of file array_userfuncs.c.

{
    bytea      *sstate;
    ArrayBuildState *result;
    StringInfoData buf;
    Oid         element_type;
    int64       nelems;
    const char *temp;
 
    if (!AggCheckCallContext(fcinfo, NULL))
        elog(ERROR, "aggregate function called in non-aggregate context");
 
    sstate = PG_GETARG_BYTEA_PP(0);
 
    /*
     * Initialize a StringInfo so that we can "receive" it using the standard
     * recv-function infrastructure.
     */
    initReadOnlyStringInfo(&buf, VARDATA_ANY(sstate),
                           VARSIZE_ANY_EXHDR(sstate));
 
    /* element_type */
    element_type = pq_getmsgint(&buf, 4);
 
    /* nelems */
    nelems = pq_getmsgint64(&buf);
 
    /* Create output ArrayBuildState with the needed number of elements */
    result = initArrayResultWithSize(element_type, CurrentMemoryContext,
                                     false, nelems);
    result->nelems = nelems;
 
    /* typlen */
    result->typlen = pq_getmsgint(&buf, 2);
 
    /* typbyval */
    result->typbyval = pq_getmsgbyte(&buf);
 
    /* typalign */
    result->typalign = pq_getmsgbyte(&buf);
 
    /* dnulls */
    temp = pq_getmsgbytes(&buf, sizeof(bool) * nelems);
    memcpy(result->dnulls, temp, sizeof(bool) * nelems);
 
    /* dvalues --- see comment in array_agg_serialize */
    if (result->typbyval)
    {
        temp = pq_getmsgbytes(&buf, sizeof(Datum) * nelems);
        memcpy(result->dvalues, temp, sizeof(Datum) * nelems);
    }
    else
    {
        DeserialIOData *iodata;
 
        /* Avoid repeat catalog lookups for typreceive function */
        iodata = (DeserialIOData *) fcinfo->flinfo->fn_extra;
        if (iodata == NULL)
        {
            Oid         typreceive;
 
            iodata = (DeserialIOData *)
                MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
                                   sizeof(DeserialIOData));
            getTypeBinaryInputInfo(element_type, &typreceive,
                                   &iodata->typioparam);
            fmgr_info_cxt(typreceive, &iodata->typreceive,
                          fcinfo->flinfo->fn_mcxt);
            fcinfo->flinfo->fn_extra = iodata;
        }
 
        for (int i = 0; i < nelems; i++)
        {
            int         itemlen;
            StringInfoData elem_buf;
 
            if (result->dnulls[i])
            {
                result->dvalues[i] = (Datum) 0;
                continue;
            }
 
            itemlen = pq_getmsgint(&buf, 4);
            if (itemlen < 0 || itemlen > (buf.len - buf.cursor))
                ereport(ERROR,
                        (errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
                         errmsg("insufficient data left in message")));
 
            /*
             * Rather than copying data around, we just initialize a
             * StringInfo pointing to the correct portion of the message
             * buffer.
             */
            initReadOnlyStringInfo(&elem_buf, &buf.data[buf.cursor], itemlen);
 
            buf.cursor += itemlen;
 
            /* Now call the element's receiveproc */
            result->dvalues[i] = ReceiveFunctionCall(&iodata->typreceive,
                                                     &elem_buf,
                                                     iodata->typioparam,
                                                     -1);
        }
    }
 
    pq_getmsgend(&buf);
 
    PG_RETURN_POINTER(result);
}

References AggCheckCallContext(), buf, CurrentMemoryContext, ArrayBuildState::dnulls, ArrayBuildState::dvalues, elog, ereport, errcode(), errmsg(), ERROR, fb(), fmgr_info_cxt(), getTypeBinaryInputInfo(), i, initArrayResultWithSize(), initReadOnlyStringInfo(), MemoryContextAlloc(), ArrayBuildState::nelems, PG_GETARG_BYTEA_PP, PG_RETURN_POINTER, pq_getmsgbyte(), pq_getmsgbytes(), pq_getmsgend(), pq_getmsgint(), pq_getmsgint64(), ReceiveFunctionCall(), ArrayBuildState::typalign, ArrayBuildState::typbyval, ArrayBuildState::typlen, VARDATA_ANY(), and VARSIZE_ANY_EXHDR().

array_agg_finalfn()

Datum array_agg_finalfn

(

PG_FUNCTION_ARGS

)

Definition at line 898 of file array_userfuncs.c.

{
    Datum       result;
    ArrayBuildState *state;
    int         dims[1];
    int         lbs[1];
 
    /* cannot be called directly because of internal-type argument */
    Assert(AggCheckCallContext(fcinfo, NULL));
 
    state = PG_ARGISNULL(0) ? NULL : (ArrayBuildState *) PG_GETARG_POINTER(0);
 
    if (state == NULL)
        PG_RETURN_NULL();       /* returns null iff no input values */
 
    dims[0] = state->nelems;
    lbs[0] = 1;
 
    /*
     * Make the result.  We cannot release the ArrayBuildState because
     * sometimes aggregate final functions are re-executed.  Rather, it is
     * nodeAgg.c's responsibility to reset the aggcontext when it's safe to do
     * so.
     */
    result = makeMdArrayResult(state, 1, dims, lbs,
                               CurrentMemoryContext,
                               false);
 
    PG_RETURN_DATUM(result);
}

References AggCheckCallContext(), Assert, CurrentMemoryContext, fb(), makeMdArrayResult(), PG_ARGISNULL, PG_GETARG_POINTER, PG_RETURN_DATUM, and PG_RETURN_NULL.

array_agg_serialize()

Datum array_agg_serialize

(

PG_FUNCTION_ARGS

)

Definition at line 698 of file array_userfuncs.c.

{
    ArrayBuildState *state;
    StringInfoData buf;
    bytea      *result;
 
    /* cannot be called directly because of internal-type argument */
    Assert(AggCheckCallContext(fcinfo, NULL));
 
    state = (ArrayBuildState *) PG_GETARG_POINTER(0);
 
    pq_begintypsend(&buf);
 
    /*
     * element_type. Putting this first is more convenient in deserialization
     */
    pq_sendint32(&buf, state->element_type);
 
    /*
     * nelems -- send first so we know how large to make the dvalues and
     * dnulls array during deserialization.
     */
    pq_sendint64(&buf, state->nelems);
 
    /* alen can be decided during deserialization */
 
    /* typlen */
    pq_sendint16(&buf, state->typlen);
 
    /* typbyval */
    pq_sendbyte(&buf, state->typbyval);
 
    /* typalign */
    pq_sendbyte(&buf, state->typalign);
 
    /* dnulls */
    pq_sendbytes(&buf, state->dnulls, sizeof(bool) * state->nelems);
 
    /*
     * dvalues.  By agreement with array_agg_deserialize, when the element
     * type is byval, we just transmit the Datum array as-is, including any
     * null elements.  For by-ref types, we must invoke the element type's
     * send function, and we skip null elements (which is why the nulls flags
     * must be sent first).
     */
    if (state->typbyval)
        pq_sendbytes(&buf, state->dvalues, sizeof(Datum) * state->nelems);
    else
    {
        SerialIOData *iodata;
        int         i;
 
        /* Avoid repeat catalog lookups for typsend function */
        iodata = (SerialIOData *) fcinfo->flinfo->fn_extra;
        if (iodata == NULL)
        {
            Oid         typsend;
            bool        typisvarlena;
 
            iodata = (SerialIOData *)
                MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
                                   sizeof(SerialIOData));
            getTypeBinaryOutputInfo(state->element_type, &typsend,
                                    &typisvarlena);
            fmgr_info_cxt(typsend, &iodata->typsend,
                          fcinfo->flinfo->fn_mcxt);
            fcinfo->flinfo->fn_extra = iodata;
        }
 
        for (i = 0; i < state->nelems; i++)
        {
            bytea      *outputbytes;
 
            if (state->dnulls[i])
                continue;
            outputbytes = SendFunctionCall(&iodata->typsend,
                                           state->dvalues[i]);
            pq_sendint32(&buf, VARSIZE(outputbytes) - VARHDRSZ);
            pq_sendbytes(&buf, VARDATA(outputbytes),
                         VARSIZE(outputbytes) - VARHDRSZ);
        }
    }
 
    result = pq_endtypsend(&buf);
 
    PG_RETURN_BYTEA_P(result);
}

References AggCheckCallContext(), Assert, buf, fb(), fmgr_info_cxt(), getTypeBinaryOutputInfo(), i, MemoryContextAlloc(), PG_GETARG_POINTER, PG_RETURN_BYTEA_P, pq_begintypsend(), pq_endtypsend(), pq_sendbyte(), pq_sendbytes(), pq_sendint16(), pq_sendint32(), pq_sendint64(), SendFunctionCall(), VARDATA(), VARHDRSZ, and VARSIZE().

array_agg_transfn()

Datum array_agg_transfn

(

PG_FUNCTION_ARGS

)

Definition at line 555 of file array_userfuncs.c.

{
    Oid         arg1_typeid = get_fn_expr_argtype(fcinfo->flinfo, 1);
    MemoryContext aggcontext;
    ArrayBuildState *state;
    Datum       elem;
 
    if (arg1_typeid == InvalidOid)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("could not determine input data type")));
 
    /*
     * Note: we do not need a run-time check about whether arg1_typeid is a
     * valid array element type, because the parser would have verified that
     * while resolving the input/result types of this polymorphic aggregate.
     */
 
    if (!AggCheckCallContext(fcinfo, &aggcontext))
    {
        /* cannot be called directly because of internal-type argument */
        elog(ERROR, "array_agg_transfn called in non-aggregate context");
    }
 
    if (PG_ARGISNULL(0))
        state = initArrayResult(arg1_typeid, aggcontext, false);
    else
        state = (ArrayBuildState *) PG_GETARG_POINTER(0);
 
    elem = PG_ARGISNULL(1) ? (Datum) 0 : PG_GETARG_DATUM(1);
 
    state = accumArrayResult(state,
                             elem,
                             PG_ARGISNULL(1),
                             arg1_typeid,
                             aggcontext);
 
    /*
     * The transition type for array_agg() is declared to be "internal", which
     * is a pass-by-value type the same size as a pointer.  So we can safely
     * pass the ArrayBuildState pointer through nodeAgg.c's machinations.
     */
    PG_RETURN_POINTER(state);
}

References accumArrayResult(), AggCheckCallContext(), elog, ereport, errcode(), errmsg(), ERROR, fb(), get_fn_expr_argtype(), initArrayResult(), InvalidOid, PG_ARGISNULL, PG_GETARG_DATUM, PG_GETARG_POINTER, and PG_RETURN_POINTER.

array_append()

Datum array_append

(

PG_FUNCTION_ARGS

)

Definition at line 139 of file array_userfuncs.c.

{
    ExpandedArrayHeader *eah;
    Datum       newelem;
    bool        isNull;
    Datum       result;
    int        *dimv,
               *lb;
    int         indx;
    ArrayMetaState *my_extra;
 
    eah = fetch_array_arg_replace_nulls(fcinfo, 0);
    isNull = PG_ARGISNULL(1);
    if (isNull)
        newelem = (Datum) 0;
    else
        newelem = PG_GETARG_DATUM(1);
 
    if (eah->ndims == 1)
    {
        /* append newelem */
        lb = eah->lbound;
        dimv = eah->dims;
 
        /* index of added elem is at lb[0] + (dimv[0] - 1) + 1 */
        if (pg_add_s32_overflow(lb[0], dimv[0], &indx))
            ereport(ERROR,
                    (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                     errmsg("integer out of range")));
    }
    else if (eah->ndims == 0)
        indx = 1;
    else
        ereport(ERROR,
                (errcode(ERRCODE_DATA_EXCEPTION),
                 errmsg("argument must be empty or one-dimensional array")));
 
    /* Perform element insertion */
    my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
 
    result = array_set_element(EOHPGetRWDatum(&eah->hdr),
                               1, &indx, newelem, isNull,
                               -1, my_extra->typlen, my_extra->typbyval, my_extra->typalign);
 
    PG_RETURN_DATUM(result);
}

References array_set_element(), EOHPGetRWDatum(), ereport, errcode(), errmsg(), ERROR, fb(), fetch_array_arg_replace_nulls(), pg_add_s32_overflow(), PG_ARGISNULL, PG_GETARG_DATUM, and PG_RETURN_DATUM.

array_append_support()

Datum array_append_support

(

PG_FUNCTION_ARGS

)

Definition at line 192 of file array_userfuncs.c.

{
    Node       *rawreq = (Node *) PG_GETARG_POINTER(0);
    Node       *ret = NULL;
 
    if (IsA(rawreq, SupportRequestModifyInPlace))
    {
        /*
         * We can optimize in-place appends if the function's array argument
         * is the array being assigned to.  We don't need to worry about array
         * references within the other argument.
         */
        SupportRequestModifyInPlace *req = (SupportRequestModifyInPlace *) rawreq;
        Param      *arg = (Param *) linitial(req->args);
 
        if (arg && IsA(arg, Param) &&
            arg->paramkind == PARAM_EXTERN &&
            arg->paramid == req->paramid)
            ret = (Node *) arg;
    }
 
    PG_RETURN_POINTER(ret);
}

References arg, fb(), IsA, linitial, PARAM_EXTERN, PG_GETARG_POINTER, and PG_RETURN_POINTER.

array_cat()

Datum array_cat

(

PG_FUNCTION_ARGS

)

Definition at line 316 of file array_userfuncs.c.

{
    ArrayType  *v1,
               *v2;
    ArrayType  *result;
    int        *dims,
               *lbs,
                ndims,
                nitems,
                ndatabytes,
                nbytes;
    int        *dims1,
               *lbs1,
                ndims1,
                nitems1,
                ndatabytes1;
    int        *dims2,
               *lbs2,
                ndims2,
                nitems2,
                ndatabytes2;
    int         i;
    char       *dat1,
               *dat2;
    bits8      *bitmap1,
               *bitmap2;
    Oid         element_type;
    Oid         element_type1;
    Oid         element_type2;
    int32       dataoffset;
 
    /* Concatenating a null array is a no-op, just return the other input */
    if (PG_ARGISNULL(0))
    {
        if (PG_ARGISNULL(1))
            PG_RETURN_NULL();
        result = PG_GETARG_ARRAYTYPE_P(1);
        PG_RETURN_ARRAYTYPE_P(result);
    }
    if (PG_ARGISNULL(1))
    {
        result = PG_GETARG_ARRAYTYPE_P(0);
        PG_RETURN_ARRAYTYPE_P(result);
    }
 
    v1 = PG_GETARG_ARRAYTYPE_P(0);
    v2 = PG_GETARG_ARRAYTYPE_P(1);
 
    element_type1 = ARR_ELEMTYPE(v1);
    element_type2 = ARR_ELEMTYPE(v2);
 
    /* Check we have matching element types */
    if (element_type1 != element_type2)
        ereport(ERROR,
                (errcode(ERRCODE_DATATYPE_MISMATCH),
                 errmsg("cannot concatenate incompatible arrays"),
                 errdetail("Arrays with element types %s and %s are not "
                           "compatible for concatenation.",
                           format_type_be(element_type1),
                           format_type_be(element_type2))));
 
    /* OK, use it */
    element_type = element_type1;
 
    /*----------
     * We must have one of the following combinations of inputs:
     * 1) one empty array, and one non-empty array
     * 2) both arrays empty
     * 3) two arrays with ndims1 == ndims2
     * 4) ndims1 == ndims2 - 1
     * 5) ndims1 == ndims2 + 1
     *----------
     */
    ndims1 = ARR_NDIM(v1);
    ndims2 = ARR_NDIM(v2);
 
    /*
     * short circuit - if one input array is empty, and the other is not, we
     * return the non-empty one as the result
     *
     * if both are empty, return the first one
     */
    if (ndims1 == 0 && ndims2 > 0)
        PG_RETURN_ARRAYTYPE_P(v2);
 
    if (ndims2 == 0)
        PG_RETURN_ARRAYTYPE_P(v1);
 
    /* the rest fall under rule 3, 4, or 5 */
    if (ndims1 != ndims2 &&
        ndims1 != ndims2 - 1 &&
        ndims1 != ndims2 + 1)
        ereport(ERROR,
                (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
                 errmsg("cannot concatenate incompatible arrays"),
                 errdetail("Arrays of %d and %d dimensions are not "
                           "compatible for concatenation.",
                           ndims1, ndims2)));
 
    /* get argument array details */
    lbs1 = ARR_LBOUND(v1);
    lbs2 = ARR_LBOUND(v2);
    dims1 = ARR_DIMS(v1);
    dims2 = ARR_DIMS(v2);
    dat1 = ARR_DATA_PTR(v1);
    dat2 = ARR_DATA_PTR(v2);
    bitmap1 = ARR_NULLBITMAP(v1);
    bitmap2 = ARR_NULLBITMAP(v2);
    nitems1 = ArrayGetNItems(ndims1, dims1);
    nitems2 = ArrayGetNItems(ndims2, dims2);
    ndatabytes1 = ARR_SIZE(v1) - ARR_DATA_OFFSET(v1);
    ndatabytes2 = ARR_SIZE(v2) - ARR_DATA_OFFSET(v2);
 
    if (ndims1 == ndims2)
    {
        /*
         * resulting array is made up of the elements (possibly arrays
         * themselves) of the input argument arrays
         */
        ndims = ndims1;
        dims = palloc_array(int, ndims);
        lbs = palloc_array(int, ndims);
 
        dims[0] = dims1[0] + dims2[0];
        lbs[0] = lbs1[0];
 
        for (i = 1; i < ndims; i++)
        {
            if (dims1[i] != dims2[i] || lbs1[i] != lbs2[i])
                ereport(ERROR,
                        (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
                         errmsg("cannot concatenate incompatible arrays"),
                         errdetail("Arrays with differing element dimensions are "
                                   "not compatible for concatenation.")));
 
            dims[i] = dims1[i];
            lbs[i] = lbs1[i];
        }
    }
    else if (ndims1 == ndims2 - 1)
    {
        /*
         * resulting array has the second argument as the outer array, with
         * the first argument inserted at the front of the outer dimension
         */
        ndims = ndims2;
        dims = palloc_array(int, ndims);
        lbs = palloc_array(int, ndims);
        memcpy(dims, dims2, ndims * sizeof(int));
        memcpy(lbs, lbs2, ndims * sizeof(int));
 
        /* increment number of elements in outer array */
        dims[0] += 1;
 
        /* make sure the added element matches our existing elements */
        for (i = 0; i < ndims1; i++)
        {
            if (dims1[i] != dims[i + 1] || lbs1[i] != lbs[i + 1])
                ereport(ERROR,
                        (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
                         errmsg("cannot concatenate incompatible arrays"),
                         errdetail("Arrays with differing dimensions are not "
                                   "compatible for concatenation.")));
        }
    }
    else
    {
        /*
         * (ndims1 == ndims2 + 1)
         *
         * resulting array has the first argument as the outer array, with the
         * second argument appended to the end of the outer dimension
         */
        ndims = ndims1;
        dims = palloc_array(int, ndims);
        lbs = palloc_array(int, ndims);
        memcpy(dims, dims1, ndims * sizeof(int));
        memcpy(lbs, lbs1, ndims * sizeof(int));
 
        /* increment number of elements in outer array */
        dims[0] += 1;
 
        /* make sure the added element matches our existing elements */
        for (i = 0; i < ndims2; i++)
        {
            if (dims2[i] != dims[i + 1] || lbs2[i] != lbs[i + 1])
                ereport(ERROR,
                        (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
                         errmsg("cannot concatenate incompatible arrays"),
                         errdetail("Arrays with differing dimensions are not "
                                   "compatible for concatenation.")));
        }
    }
 
    /* Do this mainly for overflow checking */
    nitems = ArrayGetNItems(ndims, dims);
    ArrayCheckBounds(ndims, dims, lbs);
 
    /* build the result array */
    ndatabytes = ndatabytes1 + ndatabytes2;
    if (ARR_HASNULL(v1) || ARR_HASNULL(v2))
    {
        dataoffset = ARR_OVERHEAD_WITHNULLS(ndims, nitems);
        nbytes = ndatabytes + dataoffset;
    }
    else
    {
        dataoffset = 0;         /* marker for no null bitmap */
        nbytes = ndatabytes + ARR_OVERHEAD_NONULLS(ndims);
    }
    result = (ArrayType *) palloc0(nbytes);
    SET_VARSIZE(result, nbytes);
    result->ndim = ndims;
    result->dataoffset = dataoffset;
    result->elemtype = element_type;
    memcpy(ARR_DIMS(result), dims, ndims * sizeof(int));
    memcpy(ARR_LBOUND(result), lbs, ndims * sizeof(int));
    /* data area is arg1 then arg2 */
    memcpy(ARR_DATA_PTR(result), dat1, ndatabytes1);
    memcpy(ARR_DATA_PTR(result) + ndatabytes1, dat2, ndatabytes2);
    /* handle the null bitmap if needed */
    if (ARR_HASNULL(result))
    {
        array_bitmap_copy(ARR_NULLBITMAP(result), 0,
                          bitmap1, 0,
                          nitems1);
        array_bitmap_copy(ARR_NULLBITMAP(result), nitems1,
                          bitmap2, 0,
                          nitems2);
    }
 
    PG_RETURN_ARRAYTYPE_P(result);
}

References ARR_DATA_OFFSET, ARR_DATA_PTR, ARR_DIMS, ARR_ELEMTYPE, ARR_HASNULL, ARR_LBOUND, ARR_NDIM, ARR_NULLBITMAP, ARR_OVERHEAD_NONULLS, ARR_OVERHEAD_WITHNULLS, ARR_SIZE, array_bitmap_copy(), ArrayCheckBounds(), ArrayGetNItems(), ArrayType::dataoffset, ArrayType::elemtype, ereport, errcode(), errdetail(), errmsg(), ERROR, fb(), format_type_be(), i, ArrayType::ndim, nitems, palloc0(), palloc_array, PG_ARGISNULL, PG_GETARG_ARRAYTYPE_P, PG_RETURN_ARRAYTYPE_P, PG_RETURN_NULL, and SET_VARSIZE().

array_position()

Datum array_position

(

PG_FUNCTION_ARGS

)

Definition at line 1301 of file array_userfuncs.c.

{
    return array_position_common(fcinfo);
}

References array_position_common().

array_position_common()

static Datum array_position_common ( FunctionCallInfo  fcinfo )

static

Definition at line 1320 of file array_userfuncs.c.

{
    ArrayType  *array;
    Oid         collation = PG_GET_COLLATION();
    Oid         element_type;
    Datum       searched_element,
                value;
    bool        isnull;
    int         position,
                position_min;
    bool        found = false;
    TypeCacheEntry *typentry;
    ArrayMetaState *my_extra;
    bool        null_search;
    ArrayIterator array_iterator;
 
    if (PG_ARGISNULL(0))
        PG_RETURN_NULL();
 
    array = PG_GETARG_ARRAYTYPE_P(0);
 
    /*
     * We refuse to search for elements in multi-dimensional arrays, since we
     * have no good way to report the element's location in the array.
     */
    if (ARR_NDIM(array) > 1)
        ereport(ERROR,
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("searching for elements in multidimensional arrays is not supported")));
 
    /* Searching in an empty array is well-defined, though: it always fails */
    if (ARR_NDIM(array) < 1)
        PG_RETURN_NULL();
 
    if (PG_ARGISNULL(1))
    {
        /* fast return when the array doesn't have nulls */
        if (!array_contains_nulls(array))
            PG_RETURN_NULL();
        searched_element = (Datum) 0;
        null_search = true;
    }
    else
    {
        searched_element = PG_GETARG_DATUM(1);
        null_search = false;
    }
 
    element_type = ARR_ELEMTYPE(array);
    position = (ARR_LBOUND(array))[0] - 1;
 
    /* figure out where to start */
    if (PG_NARGS() == 3)
    {
        if (PG_ARGISNULL(2))
            ereport(ERROR,
                    (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
                     errmsg("initial position must not be null")));
 
        position_min = PG_GETARG_INT32(2);
    }
    else
        position_min = (ARR_LBOUND(array))[0];
 
    /*
     * We arrange to look up type info for array_create_iterator only once per
     * series of calls, assuming the element type doesn't change underneath
     * us.
     */
    my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
    if (my_extra == NULL)
    {
        fcinfo->flinfo->fn_extra = MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
                                                      sizeof(ArrayMetaState));
        my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
        my_extra->element_type = ~element_type;
    }
 
    if (my_extra->element_type != element_type)
    {
        get_typlenbyvalalign(element_type,
                             &my_extra->typlen,
                             &my_extra->typbyval,
                             &my_extra->typalign);
 
        typentry = lookup_type_cache(element_type, TYPECACHE_EQ_OPR_FINFO);
 
        if (!OidIsValid(typentry->eq_opr_finfo.fn_oid))
            ereport(ERROR,
                    (errcode(ERRCODE_UNDEFINED_FUNCTION),
                     errmsg("could not identify an equality operator for type %s",
                            format_type_be(element_type))));
 
        my_extra->element_type = element_type;
        fmgr_info_cxt(typentry->eq_opr_finfo.fn_oid, &my_extra->proc,
                      fcinfo->flinfo->fn_mcxt);
    }
 
    /* Examine each array element until we find a match. */
    array_iterator = array_create_iterator(array, 0, my_extra);
    while (array_iterate(array_iterator, &value, &isnull))
    {
        position++;
 
        /* skip initial elements if caller requested so */
        if (position < position_min)
            continue;
 
        /*
         * Can't look at the array element's value if it's null; but if we
         * search for null, we have a hit and are done.
         */
        if (isnull || null_search)
        {
            if (isnull && null_search)
            {
                found = true;
                break;
            }
            else
                continue;
        }
 
        /* not nulls, so run the operator */
        if (DatumGetBool(FunctionCall2Coll(&my_extra->proc, collation,
                                           searched_element, value)))
        {
            found = true;
            break;
        }
    }
 
    array_free_iterator(array_iterator);
 
    /* Avoid leaking memory when handed toasted input */
    PG_FREE_IF_COPY(array, 0);
 
    if (!found)
        PG_RETURN_NULL();
 
    PG_RETURN_INT32(position);
}

References ARR_ELEMTYPE, ARR_LBOUND, ARR_NDIM, array_contains_nulls(), array_create_iterator(), array_free_iterator(), array_iterate(), array_iterator(), DatumGetBool(), TypeCacheEntry::eq_opr_finfo, ereport, errcode(), errmsg(), ERROR, fb(), FunctionCallInfoBaseData::flinfo, fmgr_info_cxt(), FmgrInfo::fn_extra, FmgrInfo::fn_mcxt, FmgrInfo::fn_oid, format_type_be(), FunctionCall2Coll(), get_typlenbyvalalign(), lookup_type_cache(), MemoryContextAlloc(), OidIsValid, PG_ARGISNULL, PG_FREE_IF_COPY, PG_GET_COLLATION, PG_GETARG_ARRAYTYPE_P, PG_GETARG_DATUM, PG_GETARG_INT32, PG_NARGS, PG_RETURN_INT32, PG_RETURN_NULL, TYPECACHE_EQ_OPR_FINFO, and value.

Referenced by array_position(), and array_position_start().

array_position_start()

Datum array_position_start

(

PG_FUNCTION_ARGS

)

Definition at line 1307 of file array_userfuncs.c.

{
    return array_position_common(fcinfo);
}

References array_position_common().

array_positions()

Datum array_positions

(

PG_FUNCTION_ARGS

)

Definition at line 1475 of file array_userfuncs.c.

{
    ArrayType  *array;
    Oid         collation = PG_GET_COLLATION();
    Oid         element_type;
    Datum       searched_element,
                value;
    bool        isnull;
    int         position;
    TypeCacheEntry *typentry;
    ArrayMetaState *my_extra;
    bool        null_search;
    ArrayIterator array_iterator;
    ArrayBuildState *astate = NULL;
 
    if (PG_ARGISNULL(0))
        PG_RETURN_NULL();
 
    array = PG_GETARG_ARRAYTYPE_P(0);
 
    /*
     * We refuse to search for elements in multi-dimensional arrays, since we
     * have no good way to report the element's location in the array.
     */
    if (ARR_NDIM(array) > 1)
        ereport(ERROR,
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("searching for elements in multidimensional arrays is not supported")));
 
    astate = initArrayResult(INT4OID, CurrentMemoryContext, false);
 
    /* Searching in an empty array is well-defined, though: it always fails */
    if (ARR_NDIM(array) < 1)
        PG_RETURN_DATUM(makeArrayResult(astate, CurrentMemoryContext));
 
    if (PG_ARGISNULL(1))
    {
        /* fast return when the array doesn't have nulls */
        if (!array_contains_nulls(array))
            PG_RETURN_DATUM(makeArrayResult(astate, CurrentMemoryContext));
        searched_element = (Datum) 0;
        null_search = true;
    }
    else
    {
        searched_element = PG_GETARG_DATUM(1);
        null_search = false;
    }
 
    element_type = ARR_ELEMTYPE(array);
    position = (ARR_LBOUND(array))[0] - 1;
 
    /*
     * We arrange to look up type info for array_create_iterator only once per
     * series of calls, assuming the element type doesn't change underneath
     * us.
     */
    my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
    if (my_extra == NULL)
    {
        fcinfo->flinfo->fn_extra = MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
                                                      sizeof(ArrayMetaState));
        my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
        my_extra->element_type = ~element_type;
    }
 
    if (my_extra->element_type != element_type)
    {
        get_typlenbyvalalign(element_type,
                             &my_extra->typlen,
                             &my_extra->typbyval,
                             &my_extra->typalign);
 
        typentry = lookup_type_cache(element_type, TYPECACHE_EQ_OPR_FINFO);
 
        if (!OidIsValid(typentry->eq_opr_finfo.fn_oid))
            ereport(ERROR,
                    (errcode(ERRCODE_UNDEFINED_FUNCTION),
                     errmsg("could not identify an equality operator for type %s",
                            format_type_be(element_type))));
 
        my_extra->element_type = element_type;
        fmgr_info_cxt(typentry->eq_opr_finfo.fn_oid, &my_extra->proc,
                      fcinfo->flinfo->fn_mcxt);
    }
 
    /*
     * Accumulate each array position iff the element matches the given
     * element.
     */
    array_iterator = array_create_iterator(array, 0, my_extra);
    while (array_iterate(array_iterator, &value, &isnull))
    {
        position += 1;
 
        /*
         * Can't look at the array element's value if it's null; but if we
         * search for null, we have a hit.
         */
        if (isnull || null_search)
        {
            if (isnull && null_search)
                astate =
                    accumArrayResult(astate, Int32GetDatum(position), false,
                                     INT4OID, CurrentMemoryContext);
 
            continue;
        }
 
        /* not nulls, so run the operator */
        if (DatumGetBool(FunctionCall2Coll(&my_extra->proc, collation,
                                           searched_element, value)))
            astate =
                accumArrayResult(astate, Int32GetDatum(position), false,
                                 INT4OID, CurrentMemoryContext);
    }
 
    array_free_iterator(array_iterator);
 
    /* Avoid leaking memory when handed toasted input */
    PG_FREE_IF_COPY(array, 0);
 
    PG_RETURN_DATUM(makeArrayResult(astate, CurrentMemoryContext));
}

References accumArrayResult(), ARR_ELEMTYPE, ARR_LBOUND, ARR_NDIM, array_contains_nulls(), array_create_iterator(), array_free_iterator(), array_iterate(), array_iterator(), CurrentMemoryContext, DatumGetBool(), TypeCacheEntry::eq_opr_finfo, ereport, errcode(), errmsg(), ERROR, fb(), fmgr_info_cxt(), FmgrInfo::fn_oid, format_type_be(), FunctionCall2Coll(), get_typlenbyvalalign(), initArrayResult(), Int32GetDatum(), lookup_type_cache(), makeArrayResult(), MemoryContextAlloc(), OidIsValid, PG_ARGISNULL, PG_FREE_IF_COPY, PG_GET_COLLATION, PG_GETARG_ARRAYTYPE_P, PG_GETARG_DATUM, PG_RETURN_DATUM, PG_RETURN_NULL, TYPECACHE_EQ_OPR_FINFO, and value.

array_prepend()

Datum array_prepend

(

PG_FUNCTION_ARGS

)

Definition at line 222 of file array_userfuncs.c.

{
    ExpandedArrayHeader *eah;
    Datum       newelem;
    bool        isNull;
    Datum       result;
    int        *lb;
    int         indx;
    int         lb0;
    ArrayMetaState *my_extra;
 
    isNull = PG_ARGISNULL(0);
    if (isNull)
        newelem = (Datum) 0;
    else
        newelem = PG_GETARG_DATUM(0);
    eah = fetch_array_arg_replace_nulls(fcinfo, 1);
 
    if (eah->ndims == 1)
    {
        /* prepend newelem */
        lb = eah->lbound;
        lb0 = lb[0];
 
        if (pg_sub_s32_overflow(lb0, 1, &indx))
            ereport(ERROR,
                    (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                     errmsg("integer out of range")));
    }
    else if (eah->ndims == 0)
    {
        indx = 1;
        lb0 = 1;
    }
    else
        ereport(ERROR,
                (errcode(ERRCODE_DATA_EXCEPTION),
                 errmsg("argument must be empty or one-dimensional array")));
 
    /* Perform element insertion */
    my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
 
    result = array_set_element(EOHPGetRWDatum(&eah->hdr),
                               1, &indx, newelem, isNull,
                               -1, my_extra->typlen, my_extra->typbyval, my_extra->typalign);
 
    /* Readjust result's LB to match the input's, as expected for prepend */
    Assert(result == EOHPGetRWDatum(&eah->hdr));
    if (eah->ndims == 1)
    {
        /* This is ok whether we've deconstructed or not */
        eah->lbound[0] = lb0;
    }
 
    PG_RETURN_DATUM(result);
}

References array_set_element(), Assert, EOHPGetRWDatum(), ereport, errcode(), errmsg(), ERROR, fb(), fetch_array_arg_replace_nulls(), PG_ARGISNULL, PG_GETARG_DATUM, PG_RETURN_DATUM, and pg_sub_s32_overflow().

array_prepend_support()

Datum array_prepend_support

(

PG_FUNCTION_ARGS

)

Definition at line 285 of file array_userfuncs.c.

{
    Node       *rawreq = (Node *) PG_GETARG_POINTER(0);
    Node       *ret = NULL;
 
    if (IsA(rawreq, SupportRequestModifyInPlace))
    {
        /*
         * We can optimize in-place prepends if the function's array argument
         * is the array being assigned to.  We don't need to worry about array
         * references within the other argument.
         */
        SupportRequestModifyInPlace *req = (SupportRequestModifyInPlace *) rawreq;
        Param      *arg = (Param *) lsecond(req->args);
 
        if (arg && IsA(arg, Param) &&
            arg->paramkind == PARAM_EXTERN &&
            arg->paramid == req->paramid)
            ret = (Node *) arg;
    }
 
    PG_RETURN_POINTER(ret);
}

References arg, fb(), IsA, lsecond, PARAM_EXTERN, PG_GETARG_POINTER, and PG_RETURN_POINTER.

array_reverse()

Datum array_reverse

(

PG_FUNCTION_ARGS

)

Definition at line 1850 of file array_userfuncs.c.

{
    ArrayType  *array = PG_GETARG_ARRAYTYPE_P(0);
    ArrayType  *result;
    Oid         elmtyp;
    TypeCacheEntry *typentry;
 
    /*
     * There is no point in reversing empty arrays or arrays with less than
     * two items.
     */
    if (ARR_NDIM(array) < 1 || ARR_DIMS(array)[0] < 2)
        PG_RETURN_ARRAYTYPE_P(array);
 
    elmtyp = ARR_ELEMTYPE(array);
    typentry = (TypeCacheEntry *) fcinfo->flinfo->fn_extra;
    if (typentry == NULL || typentry->type_id != elmtyp)
    {
        typentry = lookup_type_cache(elmtyp, 0);
        fcinfo->flinfo->fn_extra = (void *) typentry;
    }
 
    result = array_reverse_n(array, elmtyp, typentry);
 
    PG_RETURN_ARRAYTYPE_P(result);
}

References ARR_DIMS, ARR_ELEMTYPE, ARR_NDIM, array_reverse_n(), fb(), lookup_type_cache(), PG_GETARG_ARRAYTYPE_P, PG_RETURN_ARRAYTYPE_P, and TypeCacheEntry::type_id.

array_reverse_n()

static ArrayType * array_reverse_n ( ArrayType *  array, Oid  elmtyp, TypeCacheEntry *  typentry  )

static

Definition at line 1775 of file array_userfuncs.c.

{
    ArrayType  *result;
    int         ndim,
               *dims,
               *lbs,
                nelm,
                nitem,
                rdims[MAXDIM],
                rlbs[MAXDIM];
    int16       elmlen;
    bool        elmbyval;
    char        elmalign;
    Datum      *elms,
               *ielms;
    bool       *nuls,
               *inuls;
 
    ndim = ARR_NDIM(array);
    dims = ARR_DIMS(array);
    lbs = ARR_LBOUND(array);
 
    elmlen = typentry->typlen;
    elmbyval = typentry->typbyval;
    elmalign = typentry->typalign;
 
    deconstruct_array(array, elmtyp, elmlen, elmbyval, elmalign,
                      &elms, &nuls, &nelm);
 
    nitem = dims[0];            /* total number of items */
    nelm /= nitem;              /* number of elements per item */
 
    /* Reverse the array */
    ielms = elms;
    inuls = nuls;
    for (int i = 0; i < nitem / 2; i++)
    {
        int         j = (nitem - i - 1) * nelm;
        Datum      *jelms = elms + j;
        bool       *jnuls = nuls + j;
 
        /* Swap i'th and j'th items; advance ielms/inuls to next item */
        for (int k = 0; k < nelm; k++)
        {
            Datum       elm = *ielms;
            bool        nul = *inuls;
 
            *ielms++ = *jelms;
            *inuls++ = *jnuls;
            *jelms++ = elm;
            *jnuls++ = nul;
        }
    }
 
    /* Set up dimensions of the result */
    memcpy(rdims, dims, ndim * sizeof(int));
    memcpy(rlbs, lbs, ndim * sizeof(int));
    rdims[0] = nitem;
 
    result = construct_md_array(elms, nuls, ndim, rdims, rlbs,
                                elmtyp, elmlen, elmbyval, elmalign);
 
    pfree(elms);
    pfree(nuls);
 
    return result;
}

References ARR_DIMS, ARR_LBOUND, ARR_NDIM, construct_md_array(), deconstruct_array(), fb(), i, j, MAXDIM, pfree(), TypeCacheEntry::typalign, TypeCacheEntry::typbyval, and TypeCacheEntry::typlen.

Referenced by array_reverse().

array_sample()

Datum array_sample

(

PG_FUNCTION_ARGS

)

Definition at line 1736 of file array_userfuncs.c.

{
    ArrayType  *array = PG_GETARG_ARRAYTYPE_P(0);
    int         n = PG_GETARG_INT32(1);
    ArrayType  *result;
    Oid         elmtyp;
    TypeCacheEntry *typentry;
    int         nitem;
 
    nitem = (ARR_NDIM(array) < 1) ? 0 : ARR_DIMS(array)[0];
 
    if (n < 0 || n > nitem)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("sample size must be between 0 and %d", nitem)));
 
    elmtyp = ARR_ELEMTYPE(array);
    typentry = (TypeCacheEntry *) fcinfo->flinfo->fn_extra;
    if (typentry == NULL || typentry->type_id != elmtyp)
    {
        typentry = lookup_type_cache(elmtyp, 0);
        fcinfo->flinfo->fn_extra = typentry;
    }
 
    result = array_shuffle_n(array, n, false, elmtyp, typentry);
 
    PG_RETURN_ARRAYTYPE_P(result);
}

References ARR_DIMS, ARR_ELEMTYPE, ARR_NDIM, array_shuffle_n(), ereport, errcode(), errmsg(), ERROR, fb(), lookup_type_cache(), PG_GETARG_ARRAYTYPE_P, PG_GETARG_INT32, PG_RETURN_ARRAYTYPE_P, and TypeCacheEntry::type_id.

array_shuffle()

Datum array_shuffle

(

PG_FUNCTION_ARGS

)

Definition at line 1702 of file array_userfuncs.c.

{
    ArrayType  *array = PG_GETARG_ARRAYTYPE_P(0);
    ArrayType  *result;
    Oid         elmtyp;
    TypeCacheEntry *typentry;
 
    /*
     * There is no point in shuffling empty arrays or arrays with less than
     * two items.
     */
    if (ARR_NDIM(array) < 1 || ARR_DIMS(array)[0] < 2)
        PG_RETURN_ARRAYTYPE_P(array);
 
    elmtyp = ARR_ELEMTYPE(array);
    typentry = (TypeCacheEntry *) fcinfo->flinfo->fn_extra;
    if (typentry == NULL || typentry->type_id != elmtyp)
    {
        typentry = lookup_type_cache(elmtyp, 0);
        fcinfo->flinfo->fn_extra = typentry;
    }
 
    result = array_shuffle_n(array, ARR_DIMS(array)[0], true, elmtyp, typentry);
 
    PG_RETURN_ARRAYTYPE_P(result);
}

References ARR_DIMS, ARR_ELEMTYPE, ARR_NDIM, array_shuffle_n(), fb(), lookup_type_cache(), PG_GETARG_ARRAYTYPE_P, PG_RETURN_ARRAYTYPE_P, and TypeCacheEntry::type_id.

array_shuffle_n()

static ArrayType * array_shuffle_n ( ArrayType *  array, int  n, bool  keep_lb, Oid  elmtyp, TypeCacheEntry *  typentry  )

static

Definition at line 1613 of file array_userfuncs.c.

{
    ArrayType  *result;
    int         ndim,
               *dims,
               *lbs,
                nelm,
                nitem,
                rdims[MAXDIM],
                rlbs[MAXDIM];
    int16       elmlen;
    bool        elmbyval;
    char        elmalign;
    Datum      *elms,
               *ielms;
    bool       *nuls,
               *inuls;
 
    ndim = ARR_NDIM(array);
    dims = ARR_DIMS(array);
    lbs = ARR_LBOUND(array);
 
    elmlen = typentry->typlen;
    elmbyval = typentry->typbyval;
    elmalign = typentry->typalign;
 
    /* If the target array is empty, exit fast */
    if (ndim < 1 || dims[0] < 1 || n < 1)
        return construct_empty_array(elmtyp);
 
    deconstruct_array(array, elmtyp, elmlen, elmbyval, elmalign,
                      &elms, &nuls, &nelm);
 
    nitem = dims[0];            /* total number of items */
    nelm /= nitem;              /* number of elements per item */
 
    Assert(n <= nitem);         /* else it's caller error */
 
    /*
     * Shuffle array using Fisher-Yates algorithm.  Scan the array and swap
     * current item (nelm datums starting at ielms) with a randomly chosen
     * later item (nelm datums starting at jelms) in each iteration.  We can
     * stop once we've done n iterations; then first n items are the result.
     */
    ielms = elms;
    inuls = nuls;
    for (int i = 0; i < n; i++)
    {
        int         j = (int) pg_prng_uint64_range(&pg_global_prng_state, i, nitem - 1) * nelm;
        Datum      *jelms = elms + j;
        bool       *jnuls = nuls + j;
 
        /* Swap i'th and j'th items; advance ielms/inuls to next item */
        for (int k = 0; k < nelm; k++)
        {
            Datum       elm = *ielms;
            bool        nul = *inuls;
 
            *ielms++ = *jelms;
            *inuls++ = *jnuls;
            *jelms++ = elm;
            *jnuls++ = nul;
        }
    }
 
    /* Set up dimensions of the result */
    memcpy(rdims, dims, ndim * sizeof(int));
    memcpy(rlbs, lbs, ndim * sizeof(int));
    rdims[0] = n;
    if (!keep_lb)
        rlbs[0] = 1;
 
    result = construct_md_array(elms, nuls, ndim, rdims, rlbs,
                                elmtyp, elmlen, elmbyval, elmalign);
 
    pfree(elms);
    pfree(nuls);
 
    return result;
}

References ARR_DIMS, ARR_LBOUND, ARR_NDIM, Assert, construct_empty_array(), construct_md_array(), deconstruct_array(), fb(), i, j, MAXDIM, pfree(), pg_global_prng_state, pg_prng_uint64_range(), TypeCacheEntry::typalign, TypeCacheEntry::typbyval, and TypeCacheEntry::typlen.

Referenced by array_sample(), and array_shuffle().

array_sort()

Datum array_sort

(

PG_FUNCTION_ARGS

)

Definition at line 2005 of file array_userfuncs.c.

{
    ArrayType  *array = PG_GETARG_ARRAYTYPE_P(0);
 
    PG_RETURN_ARRAYTYPE_P(array_sort_internal(array,
                                              false,
                                              false,
                                              fcinfo));
}

References array_sort_internal(), PG_GETARG_ARRAYTYPE_P, and PG_RETURN_ARRAYTYPE_P.

array_sort_internal()

static ArrayType * array_sort_internal ( ArrayType *  array, bool  descending, bool  nulls_first, FunctionCallInfo  fcinfo  )

static

Definition at line 1883 of file array_userfuncs.c.

{
    ArrayType  *newarray;
    Oid         collation = PG_GET_COLLATION();
    int         ndim,
               *dims,
               *lbs;
    ArraySortCachedInfo *cache_info;
    Oid         elmtyp;
    Oid         sort_typ;
    Oid         sort_opr;
    Tuplesortstate *tuplesortstate;
    ArrayIterator array_iterator;
    Datum       value;
    bool        isnull;
    ArrayBuildStateAny *astate = NULL;
 
    ndim = ARR_NDIM(array);
    dims = ARR_DIMS(array);
    lbs = ARR_LBOUND(array);
 
    /* Quick exit if we don't need to sort */
    if (ndim < 1 || dims[0] < 2)
        return array;
 
    /* Set up cache area if we didn't already */
    cache_info = (ArraySortCachedInfo *) fcinfo->flinfo->fn_extra;
    if (cache_info == NULL)
    {
        cache_info = (ArraySortCachedInfo *)
            MemoryContextAllocZero(fcinfo->flinfo->fn_mcxt,
                                   sizeof(ArraySortCachedInfo));
        fcinfo->flinfo->fn_extra = cache_info;
    }
 
    /* Fetch and cache required data if we don't have it */
    elmtyp = ARR_ELEMTYPE(array);
    if (elmtyp != cache_info->array_meta.element_type)
    {
        TypeCacheEntry *typentry;
 
        typentry = lookup_type_cache(elmtyp,
                                     TYPECACHE_LT_OPR | TYPECACHE_GT_OPR);
        cache_info->array_meta.element_type = elmtyp;
        cache_info->array_meta.typlen = typentry->typlen;
        cache_info->array_meta.typbyval = typentry->typbyval;
        cache_info->array_meta.typalign = typentry->typalign;
        cache_info->elem_lt_opr = typentry->lt_opr;
        cache_info->elem_gt_opr = typentry->gt_opr;
        cache_info->array_type = typentry->typarray;
    }
 
    /* Identify the sort operator to use */
    if (ndim == 1)
    {
        /* Need to sort the element type */
        sort_typ = elmtyp;
        sort_opr = (descending ? cache_info->elem_gt_opr : cache_info->elem_lt_opr);
    }
    else
    {
        /* Otherwise we're sorting arrays */
        sort_typ = cache_info->array_type;
        if (!OidIsValid(sort_typ))
            ereport(ERROR,
                    (errcode(ERRCODE_UNDEFINED_OBJECT),
                     errmsg("could not find array type for data type %s",
                            format_type_be(elmtyp))));
        /* We know what operators to use for arrays */
        sort_opr = (descending ? ARRAY_GT_OP : ARRAY_LT_OP);
    }
 
    /*
     * Fail if we don't know how to sort.  The error message is chosen to
     * match what array_lt()/array_gt() will say in the multidimensional case.
     */
    if (!OidIsValid(sort_opr))
        ereport(ERROR,
                errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                errmsg("could not identify a comparison function for type %s",
                       format_type_be(elmtyp)));
 
    /* Put the things to be sorted (elements or sub-arrays) into a tuplesort */
    tuplesortstate = tuplesort_begin_datum(sort_typ,
                                           sort_opr,
                                           collation,
                                           nulls_first,
                                           work_mem,
                                           NULL,
                                           TUPLESORT_NONE);
 
    array_iterator = array_create_iterator(array, ndim - 1,
                                           &cache_info->array_meta);
    while (array_iterate(array_iterator, &value, &isnull))
    {
        tuplesort_putdatum(tuplesortstate, value, isnull);
    }
    array_free_iterator(array_iterator);
 
    /* Do the sort */
    tuplesort_performsort(tuplesortstate);
 
    /* Extract results into a new array */
    while (tuplesort_getdatum(tuplesortstate, true, false, &value, &isnull, NULL))
    {
        astate = accumArrayResultAny(astate, value, isnull,
                                     sort_typ, CurrentMemoryContext);
    }
    tuplesort_end(tuplesortstate);
 
    newarray = DatumGetArrayTypeP(makeArrayResultAny(astate,
                                                     CurrentMemoryContext,
                                                     true));
 
    /* Adjust lower bound to match the input */
    ARR_LBOUND(newarray)[0] = lbs[0];
 
    return newarray;
}

References accumArrayResultAny(), ARR_DIMS, ARR_ELEMTYPE, ARR_LBOUND, ARR_NDIM, array_create_iterator(), array_free_iterator(), array_iterate(), array_iterator(), CurrentMemoryContext, DatumGetArrayTypeP, ereport, errcode(), errmsg(), ERROR, fb(), FunctionCallInfoBaseData::flinfo, FmgrInfo::fn_extra, FmgrInfo::fn_mcxt, format_type_be(), TypeCacheEntry::gt_opr, lookup_type_cache(), TypeCacheEntry::lt_opr, makeArrayResultAny(), MemoryContextAllocZero(), OidIsValid, PG_GET_COLLATION, tuplesort_begin_datum(), tuplesort_end(), tuplesort_getdatum(), TUPLESORT_NONE, tuplesort_performsort(), tuplesort_putdatum(), TypeCacheEntry::typalign, TypeCacheEntry::typarray, TypeCacheEntry::typbyval, TYPECACHE_GT_OPR, TYPECACHE_LT_OPR, TypeCacheEntry::typlen, value, and work_mem.

Referenced by array_sort(), array_sort_order(), and array_sort_order_nulls_first().

array_sort_order()

Datum array_sort_order

(

PG_FUNCTION_ARGS

)

Definition at line 2016 of file array_userfuncs.c.

{
    ArrayType  *array = PG_GETARG_ARRAYTYPE_P(0);
    bool        descending = PG_GETARG_BOOL(1);
 
    PG_RETURN_ARRAYTYPE_P(array_sort_internal(array,
                                              descending,
                                              descending,
                                              fcinfo));
}

References array_sort_internal(), fb(), PG_GETARG_ARRAYTYPE_P, PG_GETARG_BOOL, and PG_RETURN_ARRAYTYPE_P.

array_sort_order_nulls_first()

Datum array_sort_order_nulls_first

(

PG_FUNCTION_ARGS

)

Definition at line 2028 of file array_userfuncs.c.

{
    ArrayType  *array = PG_GETARG_ARRAYTYPE_P(0);
    bool        descending = PG_GETARG_BOOL(1);
    bool        nulls_first = PG_GETARG_BOOL(2);
 
    PG_RETURN_ARRAYTYPE_P(array_sort_internal(array,
                                              descending,
                                              nulls_first,
                                              fcinfo));
}

References array_sort_internal(), fb(), PG_GETARG_ARRAYTYPE_P, PG_GETARG_BOOL, and PG_RETURN_ARRAYTYPE_P.

fetch_array_arg_replace_nulls()

static ExpandedArrayHeader * fetch_array_arg_replace_nulls ( FunctionCallInfo  fcinfo, int  argno  )

static

Definition at line 80 of file array_userfuncs.c.

{
    ExpandedArrayHeader *eah;
    Oid         element_type;
    ArrayMetaState *my_extra;
    MemoryContext resultcxt;
 
    /* If first time through, create datatype cache struct */
    my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
    if (my_extra == NULL)
    {
        my_extra = (ArrayMetaState *)
            MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
                               sizeof(ArrayMetaState));
        my_extra->element_type = InvalidOid;
        fcinfo->flinfo->fn_extra = my_extra;
    }
 
    /* Figure out which context we want the result in */
    if (!AggCheckCallContext(fcinfo, &resultcxt))
        resultcxt = CurrentMemoryContext;
 
    /* Now collect the array value */
    if (!PG_ARGISNULL(argno))
    {
        MemoryContext oldcxt = MemoryContextSwitchTo(resultcxt);
 
        eah = PG_GETARG_EXPANDED_ARRAYX(argno, my_extra);
        MemoryContextSwitchTo(oldcxt);
    }
    else
    {
        /* We have to look up the array type and element type */
        Oid         arr_typeid = get_fn_expr_argtype(fcinfo->flinfo, argno);
 
        if (!OidIsValid(arr_typeid))
            ereport(ERROR,
                    (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                     errmsg("could not determine input data type")));
        element_type = get_element_type(arr_typeid);
        if (!OidIsValid(element_type))
            ereport(ERROR,
                    (errcode(ERRCODE_DATATYPE_MISMATCH),
                     errmsg("input data type is not an array")));
 
        eah = construct_empty_expanded_array(element_type,
                                             resultcxt,
                                             my_extra);
    }
 
    return eah;
}

References AggCheckCallContext(), construct_empty_expanded_array(), CurrentMemoryContext, ereport, errcode(), errmsg(), ERROR, fb(), FunctionCallInfoBaseData::flinfo, FmgrInfo::fn_extra, FmgrInfo::fn_mcxt, get_element_type(), get_fn_expr_argtype(), InvalidOid, MemoryContextAlloc(), MemoryContextSwitchTo(), OidIsValid, PG_ARGISNULL, and PG_GETARG_EXPANDED_ARRAYX.

Referenced by array_append(), and array_prepend().