firebird-mirror/src/qli/mov.cpp

/*
 *	PROGRAM:	QLI Access Method
 *	MODULE:		mov.cpp
 *	DESCRIPTION:	Data mover and converter and comparator, etc.
 *
 * The contents of this file are subject to the Interbase Public
 * License Version 1.0 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy
 * of the License at http://www.Inprise.com/IPL.html
 *
 * Software distributed under the License is distributed on an
 * "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express
 * or implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * The Original Code was created by Inprise Corporation
 * and its predecessors. Portions created by Inprise Corporation are
 * Copyright (C) Inprise Corporation.
 *
 * All Rights Reserved.
 * Contributor(s): ______________________________________.
 */

#include "firebird.h"
#include "../jrd/ib_stdio.h"
#include <string.h>
#include "../qli/dtr.h"
#include "../jrd/jrd_time.h"
#include "../jrd/intl.h"
#include "../qli/err_proto.h"
#include "../jrd/gds_proto.h"
#include "../jrd/gdsassert.h"
#include "../qli/mov_proto.h"

static void date_error(const TEXT*, const USHORT);
static void timestamp_to_text(SLONG[2], DSC *);
static void sql_time_to_text(ULONG[1], DSC *);
static void sql_date_to_text(SLONG[1], DSC *);
static void mover_error(int, USHORT, USHORT);
static void now_to_date(const tm*, SLONG[2]);
static void numeric_to_text(const dsc*, dsc*);
static void string_to_date(const TEXT*, USHORT, SLONG[2]);
static void string_to_time(TEXT *, USHORT, SLONG[2]);
static TEXT *type_name(USHORT);



#define LETTER(c)	(c >= 'A' && c <= 'Z')
#define DIGIT(c)	(c >= '0' && c <= '9')
#define TODAY		"TODAY"
#define NOW		"NOW"
#define TOMORROW	"TOMORROW"
#define YESTERDAY	"YESTERDAY"

#define PRECISION	10000

static const TEXT *months[] = {
	"JANUARY",
	"FEBRUARY",
	"MARCH",
	"APRIL",
	"MAY",
	"JUNE",
	"JULY",
	"AUGUST",
	"SEPTEMBER",
	"OCTOBER",
	"NOVEMBER",
	"DECEMBER",
	0
};

struct dtypes_t {
	USHORT type;
	TEXT *description;
};

static const dtypes_t dtypes_table[] = {
	{ dtype_null, "NULL" },
	{ dtype_text, "character string" },
	{ dtype_cstring, "character string" },
	{ dtype_varying, "varying string" },
	{ dtype_packed, "packed decimal" },
	{ dtype_byte, "byte integer" },
	{ dtype_short, "short integer" },
	{ dtype_long, "long integer" },
	{ dtype_quad, "quadword integer" },
	{ dtype_real, "single precision floating" },
	{ dtype_double, "double precision floating" },
	{ dtype_d_float, "double precision floating" },
	{ dtype_timestamp, "date" },
	{ dtype_sql_date, "SQL date" },
	{ dtype_sql_time, "SQL time" },
	{ dtype_blob, "blob" },
	{ 0, 0 }
};


int MOVQ_compare(const dsc* arg1, const dsc* arg2)
{
/**************************************
 *
 *	M O V Q _ c o m p a r e
 *
 **************************************
 *
 * Functional description
 *	Compare two descriptors.  Return (-1, 0, 1) if a<b, a=b, or a>b.
 *
 **************************************/
	SLONG date[2];

/* Handle the simple (matched) ones first */

	if (arg1->dsc_dtype == arg2->dsc_dtype &&
		arg1->dsc_scale == arg2->dsc_scale)
	{
		const UCHAR* p1 = arg1->dsc_address;
		const UCHAR* p2 = arg2->dsc_address;

		switch (arg1->dsc_dtype) {
		case dtype_short:
			if (*(SSHORT *) p1 == *(SSHORT *) p2)
				return 0;
			if (*(SSHORT *) p1 > *(SSHORT *) p2)
				return 1;
			return -1;

		case dtype_long:
		case dtype_sql_date:
		case dtype_sql_time:
			if (*(SLONG *) p1 == *(SLONG *) p2)
				return 0;
			if (*(SLONG *) p1 > *(SLONG *) p2)
				return 1;
			return -1;

		case dtype_timestamp:
		case dtype_quad:
			if (((SLONG *) p1)[0] < ((SLONG *) p2)[0])
				return -1;
			if (((SLONG *) p1)[0] > ((SLONG *) p2)[0])
				return 1;
			if (((ULONG *) p1)[1] < ((ULONG *) p2)[1])
				return -1;
			if (((ULONG *) p1)[1] > ((ULONG *) p2)[1])
				return 1;
			return 0;

		case dtype_real:
			if (*(float *) p1 == *(float *) p2)
				return 0;
			if (*(float *) p1 > *(float *) p2)
				return 1;
			return -1;

		case dtype_double:
			if (*(double *) p1 == *(double *) p2)
				return 0;
			if (*(double *) p1 > *(double *) p2)
				return 1;
			return -1;

		case dtype_text:
			{
			    SSHORT length;
				if (arg1->dsc_length >= arg2->dsc_length) {
					if (length = arg2->dsc_length)
						do {
							if (*p1++ != *p2++)
								if (p1[-1] > p2[-1])
									return 1;
								else
									return -1;
						} while (--length);
					if (length = arg1->dsc_length - arg2->dsc_length)
						do {
							if (*p1++ != ' ')
								if (p1[-1] > ' ')
									return 1;
								else
									return -1;
						} while (--length);
					return 0;
				}
				if (length = arg1->dsc_length)
					do {
						if (*p1++ != *p2++)
							if (p1[-1] > p2[-1])
								return 1;
							else
								return -1;
					} while (--length);
				length = arg2->dsc_length - arg1->dsc_length;
				do {
					if (*p2++ != ' ')
						if (' ' > p2[-1])
							return 1;
						else
							return -1;
				} while (--length);
				return 0;
			}
		}
	}

// Handle mixed string comparisons

	if (arg1->dsc_dtype <= dtype_varying && arg2->dsc_dtype <= dtype_varying) {
	    const UCHAR* p1;
	    const UCHAR* p2;
		SSHORT length = MOVQ_get_string(arg1, (TEXT**) &p1, 0, 0);
		SSHORT length2 = MOVQ_get_string(arg2, (TEXT**) &p2, 0, 0);
		SSHORT fill = length - length2;
		if (length >= length2) {
			if (length2)
				do {
					if (*p1++ != *p2++)
						if (p1[-1] > p2[-1])
							return 1;
						else
							return -1;
				} while (--length2);
			if (fill > 0)
				do {
					if (*p1++ != ' ')
						if (p1[-1] > ' ')
							return 1;
						else
							return -1;
				} while (--fill);
			return 0;
		}
		if (length) {
			do {
				if (*p1++ != *p2++)
					if (p1[-1] > p2[-1])
						return 1;
					else
						return -1;
			} while (--length);
		}
		do {
			if (*p2++ != ' ')
				if (' ' > p2[-1])
					return 1;
				else
					return -1;
		} while (++fill);
		return 0;
	}

// Handle hetergeneous compares

	if (arg1->dsc_dtype < arg2->dsc_dtype)
		return (-MOVQ_compare(arg2, arg1));

	dsc desc;
	
	switch (arg1->dsc_dtype) {
	case dtype_timestamp:
		desc.dsc_dtype = dtype_timestamp;
		desc.dsc_length = sizeof(date);
		desc.dsc_scale = 0;
		desc.dsc_address = (UCHAR *) date;
		desc.dsc_sub_type = 0;
		MOVQ_move(arg2, &desc);
		return MOVQ_compare(arg1, &desc);

	case dtype_sql_time:
		desc.dsc_dtype = dtype_sql_time;
		desc.dsc_length = sizeof(date[0]);
		desc.dsc_scale = 0;
		desc.dsc_address = (UCHAR *) date;
		desc.dsc_sub_type = 0;
		MOVQ_move(arg2, &desc);
		return MOVQ_compare(arg1, &desc);

	case dtype_sql_date:
		desc.dsc_dtype = dtype_sql_date;
		desc.dsc_length = sizeof(date[0]);
		desc.dsc_scale = 0;
		desc.dsc_address = (UCHAR *) date;
		desc.dsc_sub_type = 0;
		MOVQ_move(arg2, &desc);
		return MOVQ_compare(arg1, &desc);

	case dtype_short:
	case dtype_long:
		{
			const SSHORT scale = MIN(arg1->dsc_scale, arg2->dsc_scale);

			const SLONG temp1 = MOVQ_get_long(arg1, scale);
			const SLONG temp2 = MOVQ_get_long(arg2, scale);
			if (temp1 == temp2)
				return 0;
			if (temp1 > temp2)
				return 1;
			return -1;
		}

	case dtype_real:
		{
			const float temp1 = MOVQ_get_double(arg1);
			const float temp2 = MOVQ_get_double(arg2);
			if (temp1 == temp2)
				return 0;
			if (temp1 > temp2)
				return 1;
			return -1;
		}

	case dtype_double:
		{
			const double temp1 = MOVQ_get_double(arg1);
			const double temp2 = MOVQ_get_double(arg2);
			if (temp1 == temp2)
				return 0;
			if (temp1 > temp2)
				return 1;
			return -1;
		}

	case dtype_blob:
		IBERROR(48);			// Msg 48 Blob conversion is not supported

	default:
		mover_error(410, arg1->dsc_dtype, arg2->dsc_dtype);

	}
	return -1;
}


double MOVQ_date_to_double(const dsc* desc)
{
/**************************************
 *
 *	M O V Q _ d a t e _ t o _ d o u b l e
 *
 **************************************
 *
 * Functional description
 *    Convert a date to double precision for
 *    date arithmetic routines.
 *
 **************************************/
	SLONG temp[2], *date;

// If the input descriptor is not in date form, convert it.

	if (desc->dsc_dtype == dtype_timestamp)
		date = (SLONG *) desc->dsc_address;
	else {
	    dsc temp_desc;
		temp_desc.dsc_dtype = dtype_timestamp;
		temp_desc.dsc_length = sizeof(temp);
		temp_desc.dsc_scale = 0;
		temp_desc.dsc_sub_type = 0;
		date = temp;
		temp_desc.dsc_address = (UCHAR *) date;
		MOVQ_move(desc, &temp_desc);
	}

	return date[0] + (double) date[1] / (24. * 60. * 60. * PRECISION);
}


int MOVQ_decompose(const TEXT* string, USHORT length, SLONG* return_value)
{
/**************************************
 *
 *	M O V Q _ d e c o m p o s e
 *
 **************************************
 *
 * Functional description
 *	Decompose a numeric string in mantissa and exponent.
 *
 **************************************/
	SSHORT scale = 0;
	SLONG value = 0;
	SCHAR temp[128];

	bool sign = false;
	bool fraction = false;

	const TEXT* p = string;
	const TEXT* const end = p + length;
	for (; p < end; p++) {
		if (*p == ',')
			continue;
		else if (DIGIT(*p)) {
			value = value * 10 + *p - '0';
			if (fraction)
				--scale;
		}
		else if (*p == '.')
			if (fraction) {
				MOVQ_terminate(string, temp, length, sizeof(temp));
				ERRQ_error(411, temp, NULL, NULL, NULL, NULL);
			}
			else
				fraction = true;
		else if (*p == '-' && !value && !sign)
			sign = true;
		else if (*p == '+' && !value && !sign)
			sign = false;
		else if (*p == 'e' || *p == 'E')
			break;
		else if (*p != ' ') {
			MOVQ_terminate(string, temp, length, sizeof(temp));
			ERRQ_error(411, temp, NULL, NULL, NULL, NULL);
		}
	}

	if (sign)
		value = -value;

/* If there's still something left, there must be an explicit
   exponent */

	if (p < end) {
		SSHORT exp = 0;
		sign = false;
		for (p++; p < end; p++) {
			if (DIGIT(*p))
				exp = exp * 10 + *p - '0';
			else if (*p == '-' && !exp)
				sign = true;
			else if (*p == '+' && !exp && !sign)
				continue;
			else if (*p != ' ') {
				MOVQ_terminate(string, temp, length, sizeof(temp));
				ERRQ_error(411, temp, NULL, NULL, NULL, NULL);
			}
		}
		if (sign)
			scale -= exp;
		else
			scale += exp;
	}

	*return_value = value;

	return scale;
}


void MOVQ_double_to_date( double real, SLONG fixed[2])
{
/**************************************
 *
 *	M O V Q _ d o u b l e _ t o _ d a t e
 *
 **************************************
 *
 * Functional description
 *	Convert a double precision representation of a date
 *	to a fixed point representation.   Double is used for
 *      date arithmetic.
 *
 **************************************/

	fixed[0] = real;
	fixed[1] = (real - fixed[0]) * 24. * 60. * 60. * PRECISION;
}


void MOVQ_fast(const SCHAR* from,
			   SCHAR* to,
			   ULONG length)
{
/**************************************
 *
 *	M O V Q _ f a s t
 *
 **************************************
 *
 * Functional description
 *	Move a byte string as fast as possible.
 *
 **************************************/

	if (length)
		do {
			*to++ = *from++;
		} while (--length);
}


double MOVQ_get_double(const dsc* desc)
{
/**************************************
 *
 *	M O V Q _ g e t _ d o u b l e
 *
 **************************************
 *
 * Functional description
 *	Convert something arbitrary to a
 *	double_precision representation.
 *
 **************************************/
	double value;
	SSHORT scale, fraction, sign, exp, length;
	TEXT *p, *end;

	switch (desc->dsc_dtype) {
	case dtype_short:
		value = *((SSHORT *) desc->dsc_address);
		break;

	case dtype_long:
		value = *((SLONG *) desc->dsc_address);
		break;

	case dtype_real:
		return *((float *) desc->dsc_address);

	case dtype_double:
		return *((double *) desc->dsc_address);

	case dtype_varying:
	case dtype_cstring:
	case dtype_text:
		length = MOVQ_get_string(desc, &p, 0, 0);
		scale = fraction = sign = value = 0;
		for (end = p + length; p < end; p++) {
			if (*p == ',')
				continue;
			else if (DIGIT(*p)) {
				value = value * 10. + (*p - '0');
				if (fraction)
					scale++;
			}
			else if (*p == '.')
				if (fraction)
					IBERROR(52);	// Msg 52 conversion error
				else
					fraction = 1;
			else if (!value && *p == '-')
				sign = 1;
			else if (!value && *p == '+')
				continue;
			else if (*p == 'e' || *p == 'E')
				break;
			else if (*p != ' ')
				IBERROR(53);	// Msg 53 conversion error
		}

		if (sign)
			value = -value;

		/* If there's still something left, there must be an explicit
		   exponent */

		if (p < end) {
			sign = exp = 0;
			for (p++; p < end; p++) {
				if (DIGIT(*p))
					exp = exp * 10 + *p - '0';
				else if (*p == '-' && !exp)
					sign = TRUE;
				else if (*p == '+' && !exp);
				else if (*p != ' ')
					IBERROR(54);	// Msg 54 conversion error
			}
			if (sign)
				scale += exp;
			else
				scale -= exp;
		}

		if (scale > 0)
			do {
				value /= 10.;
			} while (--scale);
		else if (scale)
			do {
				value *= 10.;
			} while (++scale);

		return value;

	default:
		mover_error(410, desc->dsc_dtype, dtype_double);
	}

// Last, but not least, adjust for scale

	if ((scale = desc->dsc_scale) == 0)
		return value;

	if (scale > 0)
		do {
			value *= 10.;
		} while (--scale);
	else
		do {
			value /= 10.;
		} while (++scale);

	return value;
}


SLONG MOVQ_get_long(const dsc* desc, SSHORT scale)
{
/**************************************
 *
 *	M O V Q _ g e t _ l o n g
 *
 **************************************
 *
 * Functional description
 *	Convert something arbitrary to a long (32 bit) integer of given
 *	scale.
 *
 **************************************/
	SLONG value;
	double d;
	SSHORT length;

	scale -= (SSHORT) desc->dsc_scale;

	TEXT* p = (TEXT *) desc->dsc_address;
	switch (desc->dsc_dtype) {
	case dtype_short:
		value = *((SSHORT *) p);
		break;

	case dtype_long:
		value = *((SLONG *) p);
		break;

	case dtype_real:
		d = *((float *) p);
		if (scale > 0)
			do {
				d /= 10.;
			} while (--scale);
		else if (scale < 0)
			do {
				d *= 10.;
			} while (++scale);
		if (d > 0)
			d += 0.5;
		else
			d -= 0.5;
		return (SLONG) d;

	case dtype_double:
		d = *((double *) p);
		if (scale > 0)
			do {
				d /= 10.;
			} while (--scale);
		else if (scale < 0)
			do {
				d *= 10.;
			} while (++scale);
		if (d > 0)
			d += 0.5;
		else
			d -= 0.5;
		return (SLONG) d;

	case dtype_varying:
	case dtype_cstring:
	case dtype_text:
		length = MOVQ_get_string(desc, &p, 0, 0);
		scale -= MOVQ_decompose(p, length, &value);
		break;

	default:
		mover_error(410, desc->dsc_dtype, dtype_long);
	}

// Last, but not least, adjust for scale

	if (scale == 0)
		return value;

	if (scale > 0) {
		if ((desc->dsc_dtype == dtype_short)
			|| (desc->dsc_dtype == dtype_long)) {
			SSHORT fraction = 0;
			do {
				if (scale == 1)
					fraction = value % 10;
				value /= 10;
			} while (--scale);
			if (fraction > 4)
				value++;
		}
		else
			do {
				value /= 10;
			} while (--scale);
	}
	else
		do {
			value *= 10;
		} while (++scale);

	return value;
}


int MOVQ_get_string(const dsc* desc, TEXT** address, vary* temp, USHORT length)
{
/**************************************
 *
 *	M O V Q _  g e t _ s t r i n g
 *
 **************************************
 *
 * Functional description
 *	Get address and length of string, converting the value to
 *	string, if necessary.  The caller must provide a sufficiently
 *	large temporary.  The address of the resultant string is returned
 *	by reference.  Get_string returns the length of the string.
 *
 *	Note: If the descriptor is known to be a string type, the third
 *	argument (temp buffer) may be omitted.
 *
 **************************************/

/* If the value is already a string (fixed or varying), just return
   the address and length. */

	if (desc->dsc_dtype == dtype_text) {
		*address = (TEXT *) desc->dsc_address;
		return desc->dsc_length;
	}

// Perhaps it a "C" type string?

	if (desc->dsc_dtype == dtype_cstring) {
		*address = (TEXT *) desc->dsc_address;
		return MIN(strlen((char*)desc->dsc_address), desc->dsc_length - 1);
	}

// No luck -- convert value to varying string.

	if (desc->dsc_dtype == dtype_varying) {
		vary* varying = (vary*) desc->dsc_address;
		*address = varying->vary_string;
		return varying->vary_length;
	}

	dsc temp_desc;
	temp_desc.dsc_length = length;
	temp_desc.dsc_address = (UCHAR *) temp;
	temp_desc.dsc_scale = 0;
	temp_desc.dsc_dtype = dtype_varying;
	temp_desc.dsc_sub_type = ttype_ascii;
	MOVQ_move(desc, &temp_desc);
	*address = temp->vary_string;

	return temp->vary_length;
}


void MOVQ_move(const dsc* from, dsc* to)
{
/**************************************
 *
 *	M O V Q _ m o v e
 *
 **************************************
 *
 * Functional description
 *	Move (and possible convert) something to something else.
 *
 **************************************/
	SSHORT fill;
	SLONG l;
	UCHAR *ptr;

	USHORT length = from->dsc_length;
	UCHAR* p = to->dsc_address;
	const UCHAR* q = from->dsc_address;

/* If the datatypes and lengths are identical, just move the
   stuff byte by byte.  Although this may seem slower than
   optimal, it would cost more to find the fast move than the
   fast move would gain. */

	if (DSC_EQUIV(from, to))
/*
if (((ALT_DSC*) from)->dsc_combined_type == ((ALT_DSC*) to)->dsc_combined_type)
*/
	{
		if (length)
			do {
				*p++ = *q++;
			} while (--length);
		return;
	}

/* Do data type by data type conversions.  Not all are supported,
   and some will drop out for additional handling. */

	switch (to->dsc_dtype) {
	case dtype_timestamp:
		switch (from->dsc_dtype) {
		case dtype_varying:
		case dtype_cstring:
		case dtype_text:
			length = MOVQ_get_string(from, (TEXT**) &ptr, 0, 0);
			string_to_date((TEXT*) ptr, length, (long int*)to->dsc_address);
			return;
		case dtype_sql_date:
			((SLONG *) to->dsc_address)[0] = *(SLONG *) from->dsc_address;
			((SLONG *) to->dsc_address)[1] = 0;
			return;
		case dtype_sql_time:
			((SLONG *) to->dsc_address)[0] = 0;
			((SLONG *) to->dsc_address)[1] = *(SLONG *) from->dsc_address;
			return;
		}
		break;

	case dtype_sql_date:
		switch (from->dsc_dtype) {
		case dtype_varying:
		case dtype_cstring:
		case dtype_text:
			{
				SLONG date[2];
				length = MOVQ_get_string(from, (TEXT**)&ptr, 0, 0);
				string_to_date((TEXT*) ptr, length, (long int*)date);
				((SLONG *) to->dsc_address)[0] = date[0];
			}
			return;
		case dtype_timestamp:
			((SLONG *) to->dsc_address)[0] = ((SLONG *) from->dsc_address)[0];
			return;
		case dtype_sql_time:
			// Error situation
			break;
		}
		break;

	case dtype_sql_time:
		switch (from->dsc_dtype) {
		case dtype_varying:
		case dtype_cstring:
		case dtype_text:
			{
				SLONG date[2];
				length = MOVQ_get_string(from, (TEXT**)&ptr, 0, 0);
				string_to_time((TEXT*) ptr, length, (long int*) date);
				((SLONG *) to->dsc_address)[0] = date[1];
			}
			return;
		case dtype_timestamp:
			((SLONG *) to->dsc_address)[0] = ((SLONG *) from->dsc_address)[1];
			return;
		case dtype_sql_date:
			// Error situation
			break;
		}
		break;

	case dtype_text:
	case dtype_cstring:
	case dtype_varying:
		switch (from->dsc_dtype) {
		case dtype_varying:
		case dtype_cstring:
		case dtype_text:
			length = MOVQ_get_string(from, (TEXT**)&ptr, 0, 0);
			q = ptr;
			switch (to->dsc_dtype) {
			case dtype_text:
				length = MIN(length, to->dsc_length);
				fill = to->dsc_length - length;
				if (length)
					do {
						*p++ = *q++;
					} while (--length);
				if (fill > 0)
					do {
						*p++ = ' ';
					} while (--fill);
				return;

			case dtype_cstring:
				length = MIN(length, to->dsc_length - 1);
				if (length)
					do {
						*p++ = *q++;
					} while (--length);
				*p = 0;
				return;

			case dtype_varying:
				length = MIN(length, to->dsc_length - sizeof(SSHORT));
				((vary*) p)->vary_length = length;
				p = (UCHAR*) ((vary*) p)->vary_string;
				if (length)
					do {
						*p++ = *q++;
					} while (--length);
				return;
			}

		case dtype_short:
		case dtype_long:
		case dtype_real:
		case dtype_double:
			numeric_to_text(from, to);
			return;

		case dtype_sql_date:
			sql_date_to_text((long int*) from->dsc_address, to);
			return;
		case dtype_sql_time:
			sql_time_to_text((ULONG*) from->dsc_address, to);
			return;
		case dtype_timestamp:
			timestamp_to_text((long int*) from->dsc_address, to);
			return;
		}
		break;

	case dtype_blob:
		if (from->dsc_dtype == dtype_quad) {
			((SLONG *) p)[0] = ((SLONG *) q)[0];
			((SLONG *) p)[1] = ((SLONG *) q)[1];
			return;
		}
		break;

	case dtype_quad:
		if (from->dsc_dtype == dtype_blob) {
			((SLONG *) p)[0] = ((SLONG *) q)[0];
			((SLONG *) p)[1] = ((SLONG *) q)[1];
			return;
		}
		break;

	case dtype_short:
		*(SSHORT *) p = l = MOVQ_get_long(from, to->dsc_scale);
		if (*(SSHORT *) p != l)
			IBERROR(14);		// Msg14 integer overflow
		return;

	case dtype_long:
		*(SLONG *) p = MOVQ_get_long(from, to->dsc_scale);
		return;

	case dtype_real:
		*(float *) p = MOVQ_get_double(from);
		return;

	case dtype_double:
		*(double *) p = MOVQ_get_double(from);
		return;
	}

	if (to->dsc_dtype == dtype_blob || from->dsc_dtype == dtype_blob)
		IBERROR(55);			// Msg 55 Blob conversion is not supported

	mover_error(410, from->dsc_dtype, to->dsc_dtype);
}


void MOVQ_terminate(const SCHAR* from,
					SCHAR* to,
					USHORT length,
					USHORT max_length)
{
/**************************************
 *
 *	M O V Q _ t e r m i n a t e
 *
 **************************************
 *
 * Functional description
 *	Null-terminate a possibly non-
 *	null-terminated string with max
 *	buffer room.
 *
 **************************************/

	fb_assert(max_length != 0);
	if (length) {
		length = MIN(length, max_length - 1);
		do {
			*to++ = *from++;
		} while (--length);
		*to++ = '\0';
	}
	else {
	    // It seems like the correct condition uses --max_length instead
		while (max_length-- && (*to++ = *from++));
		*--to = '\0';
	}
}


static void date_error(const TEXT* string, const USHORT length)
{
/**************************************
 *
 *	d a t e _ e r r o r
 *
 **************************************
 *
 * Functional description
 *	A date conversion error occurred.  Complain.
 *
 **************************************/
	SCHAR temp[128];

	MOVQ_terminate(string, temp, length, sizeof(temp));
	ERRQ_error(56, temp, NULL, NULL, NULL, NULL);
	// Msg 56 Error converting string \"%s\" to date
}


static void sql_date_to_text( SLONG date[1], DSC * to)
{
/**************************************
 *
 *	s q l _ d a t e _ t o _ t e x t
 *
 **************************************
 *
 * Functional description
 *	Convert date to text.
 *
 **************************************/
	tm times;
	SLONG date2[2];

	date2[0] = date[0];
	date2[1] = 0;
	isc_decode_date((ISC_QUAD*) date2, &times);

	TEXT temp[35];
	sprintf(temp, "%2d-%.3s-%04d", times.tm_mday,
			months[times.tm_mon], times.tm_year + 1900);

	TEXT* p;
	for (p = temp; *p; p++);

	dsc desc;
	desc.dsc_length = p - temp;
	desc.dsc_address = (UCHAR *) temp;
	desc.dsc_dtype = dtype_text;
	desc.dsc_scale = 0;
	desc.dsc_sub_type = ttype_ascii;

	MOVQ_move(&desc, to);
}


static void sql_time_to_text( ULONG date[1], DSC * to)
{
/**************************************
 *
 *	s q l _ t i m e _ t o _ t e x t
 *
 **************************************
 *
 * Functional description
 *	Convert sql time to text.
 *
 **************************************/
	tm times;
	SLONG date2[2];

	date2[0] = 0;
	date2[1] = date[0];

	isc_decode_date((ISC_QUAD*) date2, &times);

	TEXT temp[35];
	sprintf(temp, " %2d:%.2d:%.2d.%.4"SLONGFORMAT, times.tm_hour, times.tm_min,
			times.tm_sec, date2[1] % PRECISION);

	TEXT* p;
	for (p = temp; *p; p++);

	dsc desc;
	desc.dsc_length = p - temp;
	desc.dsc_address = (UCHAR *) temp;
	desc.dsc_dtype = dtype_text;
	desc.dsc_scale = 0;
	desc.dsc_sub_type = ttype_ascii;

	MOVQ_move(&desc, to);
}


static void timestamp_to_text( SLONG date[2], DSC * to)
{
/**************************************
 *
 *	t i m e s t a m p _ t o _ t e x t
 *
 **************************************
 *
 * Functional description
 *	Convert date to text.
 *
 **************************************/
	tm times;
	isc_decode_date((ISC_QUAD*)date, &times);

    TEXT temp[35];
	sprintf(temp, "%2d-%.3s-%04d", times.tm_mday,
			months[times.tm_mon], times.tm_year + 1900);

	if (times.tm_hour || times.tm_min || times.tm_sec || date[1]) {
		TEXT time[15];
		sprintf(time, " %2d:%.2d:%.2d.%.4"SLONGFORMAT, times.tm_hour, times.tm_min,
				times.tm_sec, date[1] % PRECISION);
		strcat(temp, time);
	}

	TEXT* p;
	for (p = temp; *p; p++);

	dsc desc;
	desc.dsc_length = p - temp;
	desc.dsc_address = (UCHAR *) temp;
	desc.dsc_dtype = dtype_text;
	desc.dsc_scale = 0;
	desc.dsc_sub_type = ttype_ascii;

	MOVQ_move(&desc, to);
}


static void mover_error( int pattern, USHORT in_type, USHORT out_type)
{
/**************************************
 *
 *	m o v e r _ e r r o r
 *
 **************************************
 *
 * Functional description
 *	Return a reasonable error for
 *	unreasonable conversions and
 *	comparisons.
 *
 **************************************/
	TEXT in_name[25], out_name[25], msg_unknown[40];

	ERRQ_msg_get(504, msg_unknown);	// Msg504 unknown datatype %d

	TEXT* in = type_name(in_type);
	if (!in) {
		in = in_name;
		sprintf(in_name, msg_unknown, in_type);
	}

	TEXT* out = type_name(out_type);
	if (!out) {
		out = out_name;
		sprintf(out, msg_unknown, out_type);
	}

	ERRQ_error(pattern, (TEXT *) in, (TEXT *) out, NULL, NULL, NULL);
}


static void now_to_date(const tm* time, SLONG date[2])
{
/**************************************
 *
 *	n o w _ t o _ d a t e
 *
 **************************************
 *
 * Functional description
 *	Convert "now" (or best guess) to
 *	a date attempting to get millisecond
 *	precision.  This unfortunately means
 *	that we use one routine for VAX, one
 *	for Apollo, and a third for Unix.
 *
 **************************************/

	isc_encode_date(time, (ISC_QUAD*)date);
}


static void numeric_to_text(const dsc* from, dsc* to)
{
/**************************************
 *
 *	n u m e r i c _ t o _ t e x t
 *
 **************************************
 *
 * Functional description
 *	Convert your basic number to nice, formatted text.
 *
 **************************************/

/* Save (or compute) scale of source.  Then convert source to ordinary
   longword. */

	SSHORT scale = from->dsc_scale;

	SSHORT pad = 0, decimal = 0;
	if (scale > 0)
		pad = scale;
	else if (scale < 0)
		decimal = 1;

	SLONG n;
	dsc intermediate;
	intermediate.dsc_dtype = dtype_long;
	intermediate.dsc_length = sizeof(SLONG);
	intermediate.dsc_scale = scale;
	intermediate.dsc_sub_type = 0;
	intermediate.dsc_address = (UCHAR *) &n;

	MOVQ_move(from, &intermediate);

// Check for negation, then convert the number to a string of digits

	SSHORT neg = 0;
	if (n < 0) {
		neg = 1;
		n = -n;
	}

	TEXT temp[32];
	TEXT* p = temp;

	do {
		*p++ = n % 10 + '0';
		n /= 10;
	} while (n);

/* Compute the total length off the field formatted.  Make sure it
   fits.  Keep in mind that routine handles both string and varying
   string fields. */

	SSHORT l = p - temp;
	const SSHORT length = l + neg + decimal + pad;

	if ((to->dsc_dtype == dtype_text && length > to->dsc_length) ||
		(to->dsc_dtype == dtype_cstring && length >= to->dsc_length) ||
		(to->dsc_dtype == dtype_varying
		 && length > to->dsc_length - sizeof(SSHORT)))
	{
		IBERROR(57);			// Msg 57 overflow during conversion
	}

	// Hopefully a cstring never reached this point.
	TEXT* q =
		(TEXT *) ((to->dsc_dtype == dtype_text) ? to->dsc_address : to->
				  dsc_address + sizeof(SSHORT));

// If negative, put in minus sign

	if (neg)
		*q++ = '-';

/* If a decimal point is required, do the formatting.  Otherwise just
   copy number */

	if (scale < 0) {
		if ((l += scale) > 0)
			do {
				*q++ = *--p;
			} while (--l);
		*q++ = '.';
		do {
			*q++ = *--p;
		} while (++scale);
	}
	else
		do {
			*q++ = *--p;
		} while (--l);

// If padding is required, do it now.

	if (pad)
		do {
			*q++ = '0';
		} while (--pad);

/* Finish up by padding (if fixed) or computing the actual length
   (varying string) */

	if (to->dsc_dtype == dtype_text) {
		if (l = to->dsc_length - length)
			do {
				*q++ = ' ';
			} while (--l);
		return;
	}

	if (to->dsc_dtype == dtype_cstring) {
		*q = 0;
		return;
	}

	*(SSHORT *) (to->dsc_address) =
		(UCHAR *) q - to->dsc_address - sizeof(SSHORT);
}


static void string_to_date(const TEXT* string, USHORT length, SLONG date[2])
{
/**************************************
 *
 *	s t r i n g _ t o _ d a t e
 *
 **************************************
 *
 * Functional description
 *	Convert an arbitrary string to a date.
 *
 **************************************/
	if (!length) {
		date[0] = date[1] = 0;
		return;
	}

	const TEXT* p = string;
	const TEXT* const end = p + length;

	USHORT month_position = 0;

	const time_t clock = time(0);
	tm* today = localtime(&clock);

	USHORT i;
	USHORT components[7];
	for (i = 0; i < 7; i++)
		components[i] = 0;

// Parse components

	TEXT temp[15];
	USHORT n, precision;
	bool year = false;

	for (i = 0; i < 7; i++) {

		/* Skip leading blanks.  If we run out of characters, we're done
		   with parse.  */

		while (p < end && *p == ' ')
			p++;
		if (p == end)
			break;

		// Handle digit or character strings

		TEXT c = UPPER(*p);
		if (DIGIT(c)) {
			precision = n = 0;
			while (p < end && DIGIT(*p)) {
				n = n * 10 + *p++ - '0';
				precision++;
			}
			if (i == 2)
				year = true;
		}
		else if (LETTER(c)) {
			TEXT* t = temp;
			while (p < end && LETTER(c)) {
				c = UPPER(*p);
				if (!LETTER(c))
					break;
				*t++ = c;
				p++;
			}
			*t = 0;
			const TEXT** month_ptr = months;
			while (true) {
				if (!*month_ptr) {
					while (++p < end)
						if (*p != ' ' && *p != '\t' && *p != 0)
							date_error(string, length);

					if (strcmp(temp, NOW) == 0) {
						now_to_date(today, date);
						return;
					}
					today->tm_hour = today->tm_min = today->tm_sec = 0;
					isc_encode_date(today, (ISC_QUAD*)date);
					if (strcmp(temp, TODAY) == 0)
						return;
					if (strcmp(temp, TOMORROW) == 0) {
						++date[0];
						return;
					}
					if (strcmp(temp, YESTERDAY) == 0) {
						--date[0];
						return;
					}
					date_error(string, length);
				}
				t = temp;
				for (const TEXT* m = *month_ptr++; *t && *t == *m; t++, m++);
				if (!*t)
					break;
			}
			n = month_ptr - months;
			month_position = i;
		}
		else {
			date_error(string, length);
			return;
		}
		components[i] = n;
		while (p < end && *p == ' ')
			p++;

		if (*p == '/' || *p == '-' || *p == ',' || *p == ':') {
			p++;
			continue;
		}
		if (*p == '.') {
			if (!month_position && i < 2)
				month_position = 1;
			p++;
			continue;
		}
	}

// Slide things into day, month, year form

	tm times;
	if (month_position) {
		times.tm_mon = components[1];
		times.tm_mday = components[0];
	}
	else {
		times.tm_mon = components[0];
		times.tm_mday = components[1];
	}

// Handle defaulting of year

	if (((times.tm_year = components[2]) == 0) && !year)
		times.tm_year = today->tm_year + 1900;
	else if (times.tm_year < 100) {
		if (times.tm_year < (today->tm_year - 50) % 100)
			times.tm_year += 2000;
		else
			times.tm_year += 1900;
	}

	times.tm_year -= 1900;
	times.tm_mon -= 1;
	times.tm_hour = components[3];
	times.tm_min = components[4];
	times.tm_sec = components[5];

// convert day/month/year to Julian and validate result

	isc_encode_date(&times, (ISC_QUAD*)date);
	tm times2;
	isc_decode_date((ISC_QUAD*)date, &times2);

	if (times.tm_year != times2.tm_year ||
		times.tm_mon != times2.tm_mon || times.tm_mday != times2.tm_mday)
		date_error(string, length);

	while (precision++ < 4)
		components[6] *= 10;

	date[1] += components[6];

}


static void string_to_time( TEXT * string, USHORT length, SLONG date[2])
{
/**************************************
 *
 *	s t r i n g _ t o _ t i m e
 *
 **************************************
 *
 * Functional description
 *	Convert an arbitrary string to a t i m e.
 *
 **************************************/
	if (!length) {
		date[0] = date[1] = 0;
		return;
	}

	const TEXT* p = string;
	const TEXT* const end = p + length;

	const time_t clock = time(0);
	const tm* today = localtime(&clock);

	USHORT i;
	USHORT components[7];
	for (i = 0; i < 7; i++)
		components[i] = 0;

// Parse components

	TEXT temp[15];
	USHORT n, precision;

	for (i = 3; i < 7; i++) {

		/* Skip leading blanks.  If we run out of characters, we're done
		   with parse.  */

		while (p < end && *p == ' ')
			p++;
		if (p == end)
			break;

		// Handle digit or character strings

		TEXT c = UPPER(*p);
		if (DIGIT(c)) {
			precision = n = 0;
			while (p < end && DIGIT(*p)) {
				n = n * 10 + *p++ - '0';
				precision++;
			}
		}
		else if (LETTER(c)) {
			TEXT* t = temp;
			while (p < end && LETTER(c)) {
				c = UPPER(*p);
				if (!LETTER(c))
					break;
				*t++ = c;
				p++;
			}
			*t = 0;
			while (++p < end)
				if (*p != ' ' && *p != '\t' && *p != 0)
					date_error(string, length);

			if (strcmp(temp, NOW) == 0) {
				now_to_date(today, date);
				return;
			}
			date_error(string, length);
		}
		else {
			date_error(string, length);
			return;
		}
		components[i] = n;
		while (p < end && *p == ' ')
			p++;

		if (*p == '/' || *p == '-' || *p == ',' || *p == ':' || *p == '.') {
			p++;
			continue;
		}

	}

	tm times;
	times.tm_hour = components[3];
	times.tm_min = components[4];
	times.tm_sec = components[5];

// convert day/month/year to Julian and validate result

	isc_encode_date(&times, (ISC_QUAD*)date);

	while (precision++ < 4)
		components[6] *= 10;

	date[1] += components[6];

}


static TEXT *type_name( USHORT dtype)
{
/**************************************
 *
 *	t y p e _ n a m e
 *
 **************************************
 *
 * Functional description
 *	Return the name of a data type.
 *
 **************************************/
	for (const dtypes_t* names = dtypes_table; names->description; names++)
		if (names->type == dtype)
			return names->description;
	return NULL;
}