First phase of work on array improvements. ARRAY[x,y,z] constructor

expressions, ARRAY(sub-SELECT) expressions, some array functions.
Polymorphic functions using ANYARRAY/ANYELEMENT argument and return
types.  Some regression tests in place, documentation is lacking.
Joe Conway, with some kibitzing from Tom Lane.

1 files changed, 436 insertions, 0 deletions

diff --git a/src/backend/utils/adt/array_userfuncs.c b/src/backend/utils/adt/array_userfuncs.c
new file mode 100644
index 00000000000..8c412675a38
--- /dev/null
+++ b/src/backend/utils/adt/array_userfuncs.c
@@ -0,0 +1,436 @@
+/*-------------------------------------------------------------------------
+ *
+ * array_userfuncs.c
+ *	  Misc user-visible array support functions
+ *
+ * Copyright (c) 2003, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/array_userfuncs.c,v 1.1 2003/04/08 23:20:02 tgl Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "catalog/pg_proc.h"
+#include "catalog/pg_type.h"
+#include "utils/array.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+
+
+/*-----------------------------------------------------------------------------
+ * singleton_array :
+ *		Form a multi-dimensional array given one starting element.
+ *
+ * - first argument is the datum with which to build the array
+ * - second argument is the number of dimensions the array should have;
+ *     defaults to 1 if no second argument is provided
+ *----------------------------------------------------------------------------
+ */
+Datum
+singleton_array(PG_FUNCTION_ARGS)
+{
+	Oid			elem_type = get_fn_expr_argtype(fcinfo, 0);
+	int			ndims;
+
+	if (elem_type == InvalidOid)
+		elog(ERROR, "Cannot determine input datatype");
+
+	if (PG_NARGS() == 2)
+		ndims = PG_GETARG_INT32(1);
+	else
+		ndims = 1;
+
+	PG_RETURN_ARRAYTYPE_P(create_singleton_array(elem_type,
+												 PG_GETARG_DATUM(0),
+												 ndims));
+}
+
+/*-----------------------------------------------------------------------------
+ * array_push :
+ *		push an element onto either end of a one-dimensional array
+ *----------------------------------------------------------------------------
+ */
+Datum
+array_push(PG_FUNCTION_ARGS)
+{
+	ArrayType  *v;
+	Datum		newelem;
+	int		   *dimv,
+			   *lb;
+	ArrayType  *result;
+	int			indx;
+	bool		isNull;
+	Oid			element_type;
+	int16		typlen;
+	bool		typbyval;
+	char		typalign;
+	Oid			arg0_typeid = get_fn_expr_argtype(fcinfo, 0);
+	Oid			arg1_typeid = get_fn_expr_argtype(fcinfo, 1);
+	Oid			arg0_elemid;
+	Oid			arg1_elemid;
+
+	if (arg0_typeid == InvalidOid || arg1_typeid == InvalidOid)
+		elog(ERROR, "array_push: cannot determine input data types");
+	arg0_elemid = get_element_type(arg0_typeid);
+	arg1_elemid = get_element_type(arg1_typeid);
+
+	if (arg0_elemid != InvalidOid)
+	{
+		v = PG_GETARG_ARRAYTYPE_P(0);
+		element_type = ARR_ELEMTYPE(v);
+		newelem = PG_GETARG_DATUM(1);
+	}
+	else if (arg1_elemid != InvalidOid)
+	{
+		v = PG_GETARG_ARRAYTYPE_P(1);
+		element_type = ARR_ELEMTYPE(v);
+		newelem = PG_GETARG_DATUM(0);
+	}
+	else
+	{
+		/* Shouldn't get here given proper type checking in parser */
+		elog(ERROR, "array_push: neither input type is an array");
+		PG_RETURN_NULL();		/* keep compiler quiet */
+	}
+
+	/* Sanity check: do we have a one-dimensional array */
+	if (ARR_NDIM(v) != 1)
+		elog(ERROR, "Arrays greater than one-dimension are not supported");
+
+	lb = ARR_LBOUND(v);
+	dimv = ARR_DIMS(v);
+	if (arg0_elemid != InvalidOid)
+	{
+		/* append newelem */
+		int	ub = dimv[0] + lb[0] - 1;
+		indx = ub + 1;
+	}
+	else
+	{
+		/* prepend newelem */
+		indx = lb[0] - 1;
+	}
+
+	get_typlenbyvalalign(element_type, &typlen, &typbyval, &typalign);
+
+	result = array_set(v, 1, &indx, newelem, -1,
+					   typlen, typbyval, typalign, &isNull);
+
+	PG_RETURN_ARRAYTYPE_P(result);
+}
+
+/*-----------------------------------------------------------------------------
+ * array_cat :
+ *		concatenate two nD arrays to form an (n+1)D array, or
+ *		push an (n-1)D array onto the end of an nD array
+ *----------------------------------------------------------------------------
+ */
+Datum
+array_cat(PG_FUNCTION_ARGS)
+{
+	ArrayType  *v1, *v2;
+	int		   *dims, *lbs, ndims, ndatabytes, nbytes;
+	int		   *dims1, *lbs1, ndims1, ndatabytes1;
+	int		   *dims2, *lbs2, ndims2, ndatabytes2;
+	char	   *dat1, *dat2;
+	Oid			element_type;
+	Oid			element_type1;
+	Oid			element_type2;
+	ArrayType  *result;
+
+	v1 = PG_GETARG_ARRAYTYPE_P(0);
+	v2 = PG_GETARG_ARRAYTYPE_P(1);
+
+	/*
+	 * We must have one of the following combinations of inputs:
+	 * 1) two arrays with ndims1 == ndims2
+	 * 2) ndims1 == ndims2 - 1
+	 * 3) ndims1 == ndims2 + 1
+	 */
+	ndims1 = ARR_NDIM(v1);
+	ndims2 = ARR_NDIM(v2);
+
+	if (ndims1 != ndims2 && ndims1 != ndims2 - 1 && ndims1 != ndims2 + 1)
+		elog(ERROR, "Cannot concatenate incompatible arrays of %d and "
+					"%d dimensions", ndims1, ndims2);
+
+	element_type1 = ARR_ELEMTYPE(v1);
+	element_type2 = ARR_ELEMTYPE(v2);
+
+	/* Do we have a matching element types */
+	if (element_type1 != element_type2)
+		elog(ERROR, "Cannot concatenate incompatible arrays with element "
+					"type %u and %u", element_type1, element_type2);
+
+	/* OK, use it */
+	element_type = element_type1;
+
+	/* 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);
+	ndatabytes1 = ARR_SIZE(v1) - ARR_OVERHEAD(ndims1);
+	ndatabytes2 = ARR_SIZE(v2) - ARR_OVERHEAD(ndims2);
+
+	if (ndims1 == ndims2)
+	{
+		/*
+		 * resulting array has two element outer array made up of input
+		 * argument arrays
+		 */
+		int		i;
+
+		ndims = ndims1 + 1;
+		dims = (int *) palloc(ndims * sizeof(int));
+		lbs = (int *) palloc(ndims * sizeof(int));
+
+		dims[0] = 2;	/* outer array made up of two input arrays */
+		lbs[0] = 1;		/* start lower bound at 1 */
+
+		for (i = 0; i < ndims1; i++)
+		{
+			if (dims1[i] != dims2[i] || lbs1[i] != lbs2[i])
+				elog(ERROR, "Cannot concatenate arrays with differing dimensions");
+
+			dims[i + 1] = dims1[i];
+			lbs[i + 1] = lbs1[i];
+		}
+	}
+	else if (ndims1 == ndims2 - 1)
+	{
+		/*
+		 * resulting array has the second argument as the outer array,
+		 * with the first argument appended to the front of the outer
+		 * dimension
+		 */
+		int		i;
+
+		ndims = ndims2;
+		dims = dims2;
+		lbs = lbs2;
+
+		/* 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])
+				elog(ERROR, "Cannot concatenate arrays with differing dimensions");
+		}
+	}
+	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
+		 */
+		int		i;
+
+		ndims = ndims1;
+		dims = dims1;
+		lbs = lbs1;
+
+		/* 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])
+				elog(ERROR, "Cannot concatenate arrays with differing dimensions");
+		}
+	}
+
+	/* build the result array */
+	ndatabytes = ndatabytes1 + ndatabytes2;
+	nbytes = ndatabytes + ARR_OVERHEAD(ndims);
+	result = (ArrayType *) palloc(nbytes);
+
+	result->size = nbytes;
+	result->ndim = ndims;
+	result->flags = 0;
+	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);
+
+	PG_RETURN_ARRAYTYPE_P(result);
+}
+
+/*----------------------------------------------------------------------------
+ * array_accum :
+ *		accumulator to build a 1-D array from input values -- this can be used
+ *		to create custom aggregates.
+ *
+ * This function is not marked strict, so we have to be careful about nulls.
+ *----------------------------------------------------------------------------
+ */
+Datum
+array_accum(PG_FUNCTION_ARGS)
+{
+	/* return NULL if both arguments are NULL */
+	if (PG_ARGISNULL(0) && PG_ARGISNULL(1))
+		PG_RETURN_NULL();
+
+	/* create a new 1-D array from the new element if the array is NULL */
+	if (PG_ARGISNULL(0))
+	{
+		Oid			tgt_type = get_fn_expr_rettype(fcinfo);
+		Oid			tgt_elem_type;
+
+		if (tgt_type == InvalidOid)
+			elog(ERROR, "Cannot determine target array type");
+		tgt_elem_type = get_element_type(tgt_type);
+		if (tgt_elem_type == InvalidOid)
+			elog(ERROR, "Target type is not an array");
+
+		PG_RETURN_ARRAYTYPE_P(create_singleton_array(tgt_elem_type,
+													 PG_GETARG_DATUM(1),
+													 1));
+	}
+
+	/* return the array if the new element is NULL */
+	if (PG_ARGISNULL(1))
+		PG_RETURN_ARRAYTYPE_P(PG_GETARG_ARRAYTYPE_P_COPY(0));
+
+	/*
+	 * Otherwise this is equivalent to array_push.  We hack the call a little
+	 * so that array_push can see the fn_expr information.
+	 */
+	return array_push(fcinfo);
+}
+
+/*-----------------------------------------------------------------------------
+ * array_assign :
+ *		assign an element of an array to a new value and return the
+ *		redefined array
+ *----------------------------------------------------------------------------
+ */
+Datum
+array_assign(PG_FUNCTION_ARGS)
+{
+	ArrayType  *v;
+	int			idx_to_chg;
+	Datum		newelem;
+	int		   *dimv,
+			   *lb, ub;
+	ArrayType  *result;
+	bool		isNull;
+	Oid			element_type;
+	int16		typlen;
+	bool		typbyval;
+	char		typalign;
+
+	v = PG_GETARG_ARRAYTYPE_P(0);
+	idx_to_chg = PG_GETARG_INT32(1);
+	newelem = PG_GETARG_DATUM(2);
+
+	/* Sanity check: do we have a one-dimensional array */
+	if (ARR_NDIM(v) != 1)
+		elog(ERROR, "Arrays greater than one-dimension are not supported");
+
+	lb = ARR_LBOUND(v);
+	dimv = ARR_DIMS(v);
+	ub = dimv[0] + lb[0] - 1;
+	if (idx_to_chg < lb[0] || idx_to_chg > ub)
+		elog(ERROR, "Cannot alter nonexistent array element: %d", idx_to_chg);
+
+	element_type = ARR_ELEMTYPE(v);
+	/* Sanity check: do we have a non-zero element type */
+	if (element_type == 0)
+		elog(ERROR, "Invalid array element type: %u", element_type);
+
+	get_typlenbyvalalign(element_type, &typlen, &typbyval, &typalign);
+
+	result = array_set(v, 1, &idx_to_chg, newelem, -1,
+					   typlen, typbyval, typalign, &isNull);
+
+	PG_RETURN_ARRAYTYPE_P(result);
+}
+
+/*-----------------------------------------------------------------------------
+ * array_subscript :
+ *		return specific element of an array
+ *----------------------------------------------------------------------------
+ */
+Datum
+array_subscript(PG_FUNCTION_ARGS)
+{
+	ArrayType  *v;
+	int			idx;
+	int		   *dimv,
+			   *lb, ub;
+	Datum		result;
+	bool		isNull;
+	Oid			element_type;
+	int16		typlen;
+	bool		typbyval;
+	char		typalign;
+
+	v = PG_GETARG_ARRAYTYPE_P(0);
+	idx = PG_GETARG_INT32(1);
+
+	/* Sanity check: do we have a one-dimensional array */
+	if (ARR_NDIM(v) != 1)
+		elog(ERROR, "Arrays greater than one-dimension are not supported");
+
+	lb = ARR_LBOUND(v);
+	dimv = ARR_DIMS(v);
+	ub = dimv[0] + lb[0] - 1;
+	if (idx < lb[0] || idx > ub)
+		elog(ERROR, "Cannot return nonexistent array element: %d", idx);
+
+	element_type = ARR_ELEMTYPE(v);
+	/* Sanity check: do we have a non-zero element type */
+	if (element_type == 0)
+		elog(ERROR, "Invalid array element type: %u", element_type);
+
+	get_typlenbyvalalign(element_type, &typlen, &typbyval, &typalign);
+
+	result = array_ref(v, 1, &idx, -1, typlen, typbyval, typalign, &isNull);
+
+	PG_RETURN_DATUM(result);
+}
+
+/*
+ * actually does the work for singleton_array(), and array_accum() if it is
+ * given a null input array.
+ */
+ArrayType *
+create_singleton_array(Oid element_type, Datum element, int ndims)
+{
+	Datum	dvalues[1];
+	int16	typlen;
+	bool	typbyval;
+	char	typalign;
+	int		dims[MAXDIM];
+	int		lbs[MAXDIM];
+	int		i;
+
+	if (element_type == 0)
+		elog(ERROR, "Invalid array element type: %u", element_type);
+	if (ndims < 1 || ndims > MAXDIM)
+		elog(ERROR, "Invalid number of dimensions %d", ndims);
+
+	dvalues[0] = element;
+
+	for (i = 0; i < ndims; i++)
+	{
+		dims[i] = 1;
+		lbs[i] = 1;
+	}
+
+	get_typlenbyvalalign(element_type, &typlen, &typbyval, &typalign);
+
+	return construct_md_array(dvalues, ndims, dims, lbs, element_type,
+							  typlen, typbyval, typalign);
+}