arrayfuncs.c

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							temp[nest_level - 1]++;
						}
					}
					break;
				default:
					if (!in_quotes)
					{
						if (*ptr == typdelim)
						{
							/*
							 * Delimiters can occur after an element start, an
							 * element completion, a quoted element
							 * completion, or a level completion.
							 */
							if (parse_state != ARRAY_ELEM_STARTED &&
								parse_state != ARRAY_ELEM_COMPLETED &&
								parse_state != ARRAY_QUOTED_ELEM_COMPLETED &&
								parse_state != ARRAY_LEVEL_COMPLETED)
								ereport(ERROR,
								(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
								 errmsg("malformed array literal: \"%s\"", str)));
							if (parse_state == ARRAY_LEVEL_COMPLETED)
								parse_state = ARRAY_LEVEL_DELIMITED;
							else
								parse_state = ARRAY_ELEM_DELIMITED;
							itemdone = true;
							nelems[nest_level - 1]++;
						}
						else if (!isspace((unsigned char) *ptr))
						{
							/*
							 * Other non-space characters must be after a
							 * level start, after an element start, or after
							 * an element delimiter. In any case we now must
							 * be past an element start.
							 */
							if (parse_state != ARRAY_LEVEL_STARTED &&
								parse_state != ARRAY_ELEM_STARTED &&
								parse_state != ARRAY_ELEM_DELIMITED)
								ereport(ERROR,
								(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
								 errmsg("malformed array literal: \"%s\"", str)));
							parse_state = ARRAY_ELEM_STARTED;
						}
					}
					break;
			}
			if (!itemdone)
				ptr++;
		}
		temp[ndim - 1]++;
		ptr++;
	}

	/* only whitespace is allowed after the closing brace */
	while (*ptr)
	{
		if (!isspace((unsigned char) *ptr++))
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
					 errmsg("malformed array literal: \"%s\"", str)));
	}

	/* special case for an empty array */
	if (empty_array)
		return 0;

	for (i = 0; i < ndim; ++i)
		dim[i] = temp[i];

	return ndim;
}

/*
 * ReadArrayStr :
 *	 parses the array string pointed to by "arrayStr" and converts the values
 *	 to internal format.  Unspecified elements are initialized to nulls.
 *	 The array dimensions must already have been determined.
 *
 * Inputs:
 *	arrayStr: the string to parse.
 *			  CAUTION: the contents of "arrayStr" will be modified!
 *	origStr: the unmodified input string, used only in error messages.
 *	nitems: total number of array elements, as already determined.
 *	ndim: number of array dimensions
 *	dim[]: array axis lengths
 *	inputproc: type-specific input procedure for element datatype.
 *	typioparam, typmod: auxiliary values to pass to inputproc.
 *	typdelim: the value delimiter (type-specific).
 *	typlen, typbyval, typalign: storage parameters of element datatype.
 *
 * Outputs:
 *	values[]: filled with converted data values.
 *	nulls[]: filled with is-null markers.
 *	*hasnulls: set TRUE iff there are any null elements.
 *	*nbytes: set to total size of data area needed (including alignment
 *		padding but not including array header overhead).
 *
 * Note that values[] and nulls[] are allocated by the caller, and must have
 * nitems elements.
 */
static void
ReadArrayStr(char *arrayStr,
			 const char *origStr,
			 int nitems,
			 int ndim,
			 int *dim,
			 FmgrInfo *inputproc,
			 Oid typioparam,
			 int32 typmod,
			 char typdelim,
			 int typlen,
			 bool typbyval,
			 char typalign,
			 Datum *values,
			 bool *nulls,
			 bool *hasnulls,
			 int32 *nbytes)
{
	int			i,
				nest_level = 0;
	char	   *srcptr;
	bool		in_quotes = false;
	bool		eoArray = false;
	bool		hasnull;
	int32		totbytes;
	int			indx[MAXDIM],
				prod[MAXDIM];

	mda_get_prod(ndim, dim, prod);
	MemSet(indx, 0, sizeof(indx));

	/* Initialize is-null markers to true */
	memset(nulls, true, nitems * sizeof(bool));

	/*
	 * We have to remove " and \ characters to create a clean item value to
	 * pass to the datatype input routine.	We overwrite each item value
	 * in-place within arrayStr to do this.  srcptr is the current scan point,
	 * and dstptr is where we are copying to.
	 *
	 * We also want to suppress leading and trailing unquoted whitespace. We
	 * use the leadingspace flag to suppress leading space.  Trailing space is
	 * tracked by using dstendptr to point to the last significant output
	 * character.
	 *
	 * The error checking in this routine is mostly pro-forma, since we expect
	 * that ArrayCount() already validated the string.
	 */
	srcptr = arrayStr;
	while (!eoArray)
	{
		bool		itemdone = false;
		bool		leadingspace = true;
		bool		hasquoting = false;
		char	   *itemstart;
		char	   *dstptr;
		char	   *dstendptr;

		i = -1;
		itemstart = dstptr = dstendptr = srcptr;

		while (!itemdone)
		{
			switch (*srcptr)
			{
				case '\0':
					/* Signal a premature end of the string */
					ereport(ERROR,
							(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
							 errmsg("malformed array literal: \"%s\"",
									origStr)));
					break;
				case '\\':
					/* Skip backslash, copy next character as-is. */
					srcptr++;
					if (*srcptr == '\0')
						ereport(ERROR,
								(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
								 errmsg("malformed array literal: \"%s\"",
										origStr)));
					*dstptr++ = *srcptr++;
					/* Treat the escaped character as non-whitespace */
					leadingspace = false;
					dstendptr = dstptr;
					hasquoting = true;	/* can't be a NULL marker */
					break;
				case '\"':
					in_quotes = !in_quotes;
					if (in_quotes)
						leadingspace = false;
					else
					{
						/*
						 * Advance dstendptr when we exit in_quotes; this
						 * saves having to do it in all the other in_quotes
						 * cases.
						 */
						dstendptr = dstptr;
					}
					hasquoting = true;	/* can't be a NULL marker */
					srcptr++;
					break;
				case '{':
					if (!in_quotes)
					{
						if (nest_level >= ndim)
							ereport(ERROR,
							   (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
								errmsg("malformed array literal: \"%s\"",
									   origStr)));
						nest_level++;
						indx[nest_level - 1] = 0;
						srcptr++;
					}
					else
						*dstptr++ = *srcptr++;
					break;
				case '}':
					if (!in_quotes)
					{
						if (nest_level == 0)
							ereport(ERROR,
							   (errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
								errmsg("malformed array literal: \"%s\"",
									   origStr)));
						if (i == -1)
							i = ArrayGetOffset0(ndim, indx, prod);
						indx[nest_level - 1] = 0;
						nest_level--;
						if (nest_level == 0)
							eoArray = itemdone = true;
						else
							indx[nest_level - 1]++;
						srcptr++;
					}
					else
						*dstptr++ = *srcptr++;
					break;
				default:
					if (in_quotes)
						*dstptr++ = *srcptr++;
					else if (*srcptr == typdelim)
					{
						if (i == -1)
							i = ArrayGetOffset0(ndim, indx, prod);
						itemdone = true;
						indx[ndim - 1]++;
						srcptr++;
					}
					else if (isspace((unsigned char) *srcptr))
					{
						/*
						 * If leading space, drop it immediately.  Else, copy
						 * but don't advance dstendptr.
						 */
						if (leadingspace)
							srcptr++;
						else
							*dstptr++ = *srcptr++;
					}
					else
					{
						*dstptr++ = *srcptr++;
						leadingspace = false;
						dstendptr = dstptr;
					}
					break;
			}
		}

		Assert(dstptr < srcptr);
		*dstendptr = '\0';

		if (i < 0 || i >= nitems)
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
					 errmsg("malformed array literal: \"%s\"",
							origStr)));

		if (Array_nulls && !hasquoting &&
			pg_strcasecmp(itemstart, "NULL") == 0)
		{
			/* it's a NULL item */
			values[i] = InputFunctionCall(inputproc, NULL,
										  typioparam, typmod);
			nulls[i] = true;
		}
		else
		{
			values[i] = InputFunctionCall(inputproc, itemstart,
										  typioparam, typmod);
			nulls[i] = false;
		}
	}

	/*
	 * Check for nulls, compute total data space needed
	 */
	hasnull = false;
	totbytes = 0;
	for (i = 0; i < nitems; i++)
	{
		if (nulls[i])
			hasnull = true;
		else
		{
			/* let's just make sure data is not toasted */
			if (typlen == -1)
				values[i] = PointerGetDatum(PG_DETOAST_DATUM(values[i]));
			totbytes = att_addlength_datum(totbytes, typlen, values[i]);
			totbytes = att_align_nominal(totbytes, typalign);
			/* check for overflow of total request */
			if (!AllocSizeIsValid(totbytes))
				ereport(ERROR,
						(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
						 errmsg("array size exceeds the maximum allowed (%d)",
								(int) MaxAllocSize)));
		}
	}
	*hasnulls = hasnull;
	*nbytes = totbytes;
}


/*
 * Copy data into an array object from a temporary array of Datums.
 *
 * array: array object (with header fields already filled in)
 * values: array of Datums to be copied
 * nulls: array of is-null flags (can be NULL if no nulls)
 * nitems: number of Datums to be copied
 * typbyval, typlen, typalign: info about element datatype
 * freedata: if TRUE and element type is pass-by-ref, pfree data values
 * referenced by Datums after copying them.
 *
 * If the input data is of varlena type, the caller must have ensured that
 * the values are not toasted.	(Doing it here doesn't work since the
 * caller has already allocated space for the array...)
 */
static void
CopyArrayEls(ArrayType *array,
			 Datum *values,
			 bool *nulls,
			 int nitems,
			 int typlen,
			 bool typbyval,
			 char typalign,
			 bool freedata)
{
	char	   *p = ARR_DATA_PTR(array);
	bits8	   *bitmap = ARR_NULLBITMAP(array);
	int			bitval = 0;
	int			bitmask = 1;
	int			i;

	if (typbyval)
		freedata = false;

	for (i = 0; i < nitems; i++)
	{
		if (nulls && nulls[i])
		{
			if (!bitmap)		/* shouldn't happen */
				elog(ERROR, "null array element where not supported");
			/* bitmap bit stays 0 */
		}
		else
		{
			bitval |= bitmask;
			p += ArrayCastAndSet(values[i], typlen, typbyval, typalign, p);
			if (freedata)
				pfree(DatumGetPointer(values[i]));
		}
		if (bitmap)
		{
			bitmask <<= 1;
			if (bitmask == 0x100)
			{
				*bitmap++ = bitval;
				bitval = 0;
				bitmask = 1;
			}
		}
	}

	if (bitmap && bitmask != 1)
		*bitmap = bitval;
}

/*
 * array_out :
 *		   takes the internal representation of an array and returns a string
 *		  containing the array in its external format.
 */
Datum
array_out(PG_FUNCTION_ARGS)
{
	ArrayType  *v = PG_GETARG_ARRAYTYPE_P(0);
	Oid			element_type = ARR_ELEMTYPE(v);
	int			typlen;
	bool		typbyval;
	char		typalign;
	char		typdelim;
	char	   *p,
			   *tmp,
			   *retval,
			  **values,
				dims_str[(MAXDIM * 33) + 2];

	/*
	 * 33 per dim since we assume 15 digits per number + ':' +'[]'
	 *
	 * +2 allows for assignment operator + trailing null
	 */
	bits8	   *bitmap;
	int			bitmask;
	bool	   *needquotes,
				needdims = false;
	int			nitems,
				overall_length,
				i,
				j,
				k,
				indx[MAXDIM];
	int			ndim,
			   *dims,
			   *lb;
	ArrayMetaState *my_extra;

	/*
	 * We arrange to look up info about element type, including its output
	 * conversion proc, 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 info about element type, including its output conversion proc
		 */
		get_type_io_data(element_type, IOFunc_output,
						 &my_extra->typlen, &my_extra->typbyval,
						 &my_extra->typalign, &my_extra->typdelim,
						 &my_extra->typioparam, &my_extra->typiofunc);
		fmgr_info_cxt(my_extra->typiofunc, &my_extra->proc,
					  fcinfo->flinfo->fn_mcxt);
		my_extra->element_type = element_type;
	}
	typlen = my_extra->typlen;
	typbyval = my_extra->typbyval;
	typalign = my_extra->typalign;
	typdelim = my_extra->typdelim;

	ndim = ARR_NDIM(v);
	dims = ARR_DIMS(v);
	lb = ARR_LBOUND(v);
	nitems = ArrayGetNItems(ndim, dims);

	if (nitems == 0)
	{
		retval = pstrdup("{}");
		PG_RETURN_CSTRING(retval);
	}

	/*
	 * we will need to add explicit dimensions if any dimension has a lower
	 * bound other than one
	 */
	for (i = 0; i < ndim; i++)
	{
		if (lb[i] != 1)
		{
			needdims = true;
			break;
		}
	}

	/*
	 * Convert all values to string form, count total space needed (including
	 * any overhead such as escaping backslashes), and detect whether each
	 * item needs double quotes.
	 */
	values = (char **) palloc(nitems * sizeof(char *));
	needquotes = (bool *) palloc(nitems * sizeof(bool));
	overall_length = 1;			/* don't forget to count \0 at end. */

	p = ARR_DATA_PTR(v);
	bitmap = ARR_NULLBITMAP(v);