[Tarantool-patches] [PATCH v2 3/4] sql: introduce mem_cmp_scalar()

[Timur Safin]

LGTM, yup, it's much simpler now!

: From: imeevma at tarantool.org <imeevma at tarantool.org>
: Subject: [PATCH v2 3/4] sql: introduce mem_cmp_scalar()
: 
: This patch introduces the mem_cmp_scalar() function that compares two
: MEMs using SCALAR rules. MEMs must be scalars. Prior to this patch, there
: was a
: function that used SCALAR rules to compare two MEMs, but its design became
: overly complex as new types appeared.
: 
: Part of #6164


: @@ -2030,6 +2068,36 @@ mem_cmp_uuid(const struct Mem *a, const struct Mem
: *b, int *result)
:  	return 0;
:  }
: 
: +int
: +mem_cmp_scalar(const struct Mem *a, const struct Mem *b, int *result,
: +	       const struct coll *coll)
: +{
: +	enum mem_class class_a = mem_type_class(a->type);
: +	enum mem_class class_b = mem_type_class(b->type);
: +	if (class_a != class_b) {
: +		*result = class_a - class_b;
: +		return 0;
: +	}
: +	switch (class_a) {
: +	case MEM_CLASS_NULL:
: +		*result = 0;
: +		return 0;
: +	case MEM_CLASS_BOOL:
: +		return mem_cmp_bool(a, b, result);
: +	case MEM_CLASS_NUMBER:
: +		return mem_cmp_num(a, b, result);
: +	case MEM_CLASS_STR:
: +		return mem_cmp_str(a, b, result, coll);
: +	case MEM_CLASS_BIN:
: +		return mem_cmp_bin(a, b, result);
: +	case MEM_CLASS_UUID:
: +		return mem_cmp_uuid(a, b, result);
: +	default:
: +		unreachable();
: +	}
: +	return 0;
: +}
: +
:  /*
:   * Both *pMem1 and *pMem2 contain string values. Compare the two values
:   * using the collation sequence pColl. As usual, return a negative , zero
: @@ -2463,82 +2531,6 @@ sqlVdbeMemTooBig(Mem * p)
:  	return 0;
:  }
: 
: -/*
: - * Compare the values contained by the two memory cells, returning
: - * negative, zero or positive if pMem1 is less than, equal to, or greater
: - * than pMem2. Sorting order is NULL's first, followed by numbers (integers
: - * and reals) sorted numerically, followed by text ordered by the collating
: - * sequence pColl and finally blob's ordered by memcmp().
: - *
: - * Two NULL values are considered equal by this function.
: - */
: -int
: -sqlMemCompare(const Mem * pMem1, const Mem * pMem2, const struct coll *
: pColl)
: -{
: -	int res;
: -
: -	enum mem_type type1 = pMem1->type;
: -	enum mem_type type2 = pMem2->type;
: -
: -	/* If one value is NULL, it is less than the other. If both values
: -	 * are NULL, return 0.
: -	 */
: -	if (((type1 | type2) & MEM_TYPE_NULL) != 0)
: -		return (int)(type2 == MEM_TYPE_NULL) -
: -		       (int)(type1 == MEM_TYPE_NULL);
: -
: -	if (((type1 | type2) & MEM_TYPE_BOOL) != 0) {
: -		if ((type1 & type2 & MEM_TYPE_BOOL) != 0) {
: -			if (pMem1->u.b == pMem2->u.b)
: -				return 0;
: -			if (pMem1->u.b)
: -				return 1;
: -			return -1;
: -		}
: -		if (type2 == MEM_TYPE_BOOL)
: -			return +1;
: -		return -1;
: -	}
: -
: -	if (((type1 | type2) & MEM_TYPE_UUID) != 0) {
: -		if (mem_cmp_uuid(pMem1, pMem2, &res) == 0)
: -			return res;
: -		if (type1 != MEM_TYPE_UUID)
: -			return +1;
: -		return -1;
: -	}
: -
: -	/* At least one of the two values is a number
: -	 */
: -	if (((type1 | type2) &
: -	     (MEM_TYPE_INT | MEM_TYPE_UINT | MEM_TYPE_DOUBLE)) != 0) {
: -		if (!mem_is_num(pMem1))
: -			return +1;
: -		if (!mem_is_num(pMem2))
: -			return -1;
: -		mem_cmp_num(pMem1, pMem2, &res);
: -		return res;
: -	}
: -
: -	/* If one value is a string and the other is a blob, the string is
: less.
: -	 * If both are strings, compare using the collating functions.
: -	 */
: -	if (((type1 | type2) & MEM_TYPE_STR) != 0) {
: -		if (type1 != MEM_TYPE_STR) {
: -			return 1;
: -		}
: -		if (type2 != MEM_TYPE_STR) {
: -			return -1;
: -		}
: -		mem_cmp_str(pMem1, pMem2, &res, pColl);
: -		return res;
: -	}
: -
: -	/* Both values must be blobs.  Compare using memcmp().  */
: -	mem_cmp_bin(pMem1, pMem2, &res);
: -	return res;
: -}
: -
:  int
:  sql_vdbemem_finalize(struct Mem *mem, struct func *func)
:  {