[Tarantool-patches] [PATCH v5 43/52] sql: introduce mem_cast_explicit()
imeevma at tarantool.org
imeevma at tarantool.org
Fri Apr 9 23:53:42 MSK 2021
Thank you for the review! My answer and new patch below.
On 30.03.2021 02:08, Vladislav Shpilevoy wrote:
> Thanks for the patch!
>
> In function names we use subject_action_object pattern. So it
> should be mem_cast_explicit(), the same for the implicit cast.
Fixed.
New patch:
commit 83460913f3fdab50eb49ee0b3d84a69da6e29128
Author: Mergen Imeev <imeevma at gmail.com>
Date: Wed Mar 17 12:27:09 2021 +0300
sql: introduce mem_cast_explicit()
This patch introduces mem_cast_explicit(). This function is used to
convert a MEM to a given field type according to explicit cast rules.
Part of #5818
diff --git a/src/box/sql/mem.c b/src/box/sql/mem.c
index be7b47e76..45d2d5fe3 100644
--- a/src/box/sql/mem.c
+++ b/src/box/sql/mem.c
@@ -946,6 +946,131 @@ mem_to_str(struct Mem *mem)
return -1;
}
+static inline int
+bytes_to_uint(struct Mem *mem)
+{
+ bool is_neg;
+ int64_t i;
+ if (sql_atoi64(mem->z, &i, &is_neg, mem->n) != 0)
+ return -1;
+ if (is_neg)
+ return -1;
+ mem_set_uint(mem, (uint64_t)i);
+ return 0;
+}
+
+static inline int
+str_to_bool(struct Mem *mem)
+{
+ char *str = mem->z;
+ bool b;
+ const char *str_true = "TRUE";
+ const char *str_false = "FALSE";
+ uint32_t len_true = strlen(str_true);
+ uint32_t len_false = strlen(str_false);
+
+ for (; str[0] == ' '; str++);
+ if (strncasecmp(str, str_true, len_true) == 0) {
+ b = true;
+ str += len_true;
+ } else if (strncasecmp(str, str_false, len_false) == 0) {
+ b = false;
+ str += len_false;
+ } else {
+ return -1;
+ }
+ for (; str[0] == ' '; str++);
+ if (str[0] != '\0')
+ return -1;
+ mem_set_bool(mem, b);
+ return 0;
+}
+
+static inline int
+int_to_bool(struct Mem *mem)
+{
+ mem->u.b = mem->u.i != 0;
+ mem->flags = MEM_Bool;
+ mem->field_type = FIELD_TYPE_BOOLEAN;
+ return 0;
+}
+
+static inline int
+double_to_bool(struct Mem *mem)
+{
+ mem->u.b = mem->u.r != 0.;
+ mem->flags = MEM_Bool;
+ mem->field_type = FIELD_TYPE_BOOLEAN;
+ return 0;
+}
+
+static inline int
+str_to_bin(struct Mem *mem)
+{
+ mem->flags = (mem->flags & (MEM_Dyn | MEM_Static | MEM_Ephem)) |
+ MEM_Blob;
+ mem->field_type = FIELD_TYPE_VARBINARY;
+ return 0;
+}
+
+int
+mem_cast_explicit(struct Mem *mem, enum field_type type)
+{
+ if ((mem->flags & MEM_Null) != 0) {
+ mem->field_type = type;
+ return 0;
+ }
+ switch (type) {
+ case FIELD_TYPE_UNSIGNED:
+ if ((mem->flags & MEM_UInt) != 0)
+ return 0;
+ if ((mem->flags & MEM_Int) != 0)
+ return -1;
+ if ((mem->flags & MEM_Blob) != 0 &&
+ (mem->flags & MEM_Subtype) != 0)
+ return -1;
+ if ((mem->flags & (MEM_Str | MEM_Blob)) != 0)
+ return bytes_to_uint(mem);
+ if ((mem->flags & MEM_Real) != 0)
+ return double_to_int(mem);
+ if ((mem->flags & MEM_Bool) != 0)
+ return bool_to_int(mem);
+ return -1;
+ case FIELD_TYPE_STRING:
+ return mem_to_str(mem);
+ case FIELD_TYPE_DOUBLE:
+ return mem_to_double(mem);
+ case FIELD_TYPE_INTEGER:
+ return mem_to_int(mem);
+ case FIELD_TYPE_BOOLEAN:
+ if ((mem->flags & MEM_Bool) != 0)
+ return 0;
+ if ((mem->flags & (MEM_UInt | MEM_Int)) != 0)
+ return int_to_bool(mem);
+ if ((mem->flags & MEM_Str) != 0)
+ return str_to_bool(mem);
+ if ((mem->flags & MEM_Real) != 0)
+ return double_to_bool(mem);
+ return -1;
+ case FIELD_TYPE_VARBINARY:
+ if ((mem->flags & MEM_Blob) != 0)
+ return 0;
+ if ((mem->flags & MEM_Str) != 0)
+ return str_to_bin(mem);
+ return -1;
+ case FIELD_TYPE_NUMBER:
+ return mem_to_number(mem);
+ case FIELD_TYPE_SCALAR:
+ if ((mem->flags & MEM_Blob) != 0 &&
+ (mem->flags & MEM_Subtype) != 0)
+ return -1;
+ return 0;
+ default:
+ break;
+ }
+ return -1;
+}
+
int
mem_copy(struct Mem *to, const struct Mem *from)
{
@@ -1647,42 +1772,6 @@ valueToText(sql_value * pVal)
return pVal->z;
}
-/**
- * According to ANSI SQL string value can be converted to boolean
- * type if string consists of literal "true" or "false" and
- * number of leading and trailing spaces.
- *
- * For instance, " tRuE " can be successfully converted to
- * boolean value true.
- *
- * @param str String to be converted to boolean. Assumed to be
- * null terminated.
- * @param[out] result Resulting value of cast.
- * @retval 0 If string satisfies conditions above.
- * @retval -1 Otherwise.
- */
-static int
-str_cast_to_boolean(const char *str, bool *result)
-{
- assert(str != NULL);
- for (; *str == ' '; str++);
- if (strncasecmp(str, SQL_TOKEN_TRUE, strlen(SQL_TOKEN_TRUE)) == 0) {
- *result = true;
- str += 4;
- } else if (strncasecmp(str, SQL_TOKEN_FALSE,
- strlen(SQL_TOKEN_FALSE)) == 0) {
- *result = false;
- str += 5;
- } else {
- return -1;
- }
- for (; *str != '\0'; ++str) {
- if (*str != ' ')
- return -1;
- }
- return 0;
-}
-
/*
* Convert a 64-bit IEEE double into a 64-bit signed integer.
* If the double is out of range of a 64-bit signed integer then
@@ -2018,113 +2107,6 @@ registerTrace(int iReg, Mem *p) {
}
#endif
-/*
- * Cast the datatype of the value in pMem according to the type
- * @type. Casting is different from applying type in that a cast
- * is forced. In other words, the value is converted into the desired
- * type even if that results in loss of data. This routine is
- * used (for example) to implement the SQL "cast()" operator.
- */
-int
-sqlVdbeMemCast(Mem * pMem, enum field_type type)
-{
- assert(type < field_type_MAX);
- if (pMem->flags & MEM_Null)
- return 0;
- switch (type) {
- case FIELD_TYPE_SCALAR:
- return 0;
- case FIELD_TYPE_BOOLEAN:
- if ((pMem->flags & MEM_Int) != 0) {
- mem_set_bool(pMem, pMem->u.i);
- return 0;
- }
- if ((pMem->flags & MEM_UInt) != 0) {
- mem_set_bool(pMem, pMem->u.u);
- return 0;
- }
- if ((pMem->flags & MEM_Real) != 0) {
- mem_set_bool(pMem, pMem->u.r);
- return 0;
- }
- if ((pMem->flags & MEM_Str) != 0) {
- bool value;
- if (str_cast_to_boolean(pMem->z, &value) != 0)
- return -1;
- mem_set_bool(pMem, value);
- return 0;
- }
- if ((pMem->flags & MEM_Bool) != 0)
- return 0;
- return -1;
- case FIELD_TYPE_INTEGER:
- case FIELD_TYPE_UNSIGNED:
- if ((pMem->flags & (MEM_Blob | MEM_Str)) != 0) {
- bool is_neg;
- int64_t val;
- if (sql_atoi64(pMem->z, &val, &is_neg, pMem->n) != 0)
- return -1;
- if (type == FIELD_TYPE_UNSIGNED && is_neg)
- return -1;
- mem_set_int(pMem, val, is_neg);
- return 0;
- }
- if ((pMem->flags & MEM_Bool) != 0) {
- pMem->u.u = (uint64_t)pMem->u.b;
- pMem->flags = MEM_UInt;
- pMem->field_type = FIELD_TYPE_UNSIGNED;
- return 0;
- }
- if ((pMem->flags & MEM_Real) != 0) {
- double d = pMem->u.r;
- if (d < 0. && d >= (double)INT64_MIN) {
- pMem->u.i = (int64_t)d;
- pMem->flags = MEM_Int;
- pMem->field_type = FIELD_TYPE_INTEGER;
- return 0;
- }
- if (d >= 0. && d < (double)UINT64_MAX) {
- pMem->u.u = (uint64_t)d;
- pMem->flags = MEM_UInt;
- pMem->field_type = FIELD_TYPE_UNSIGNED;
- return 0;
- }
- return -1;
- }
- if (type == FIELD_TYPE_UNSIGNED &&
- (pMem->flags & MEM_UInt) == 0)
- return -1;
- return 0;
- case FIELD_TYPE_DOUBLE:
- return mem_to_double(pMem);
- case FIELD_TYPE_NUMBER:
- return mem_to_number(pMem);
- case FIELD_TYPE_VARBINARY:
- if ((pMem->flags & MEM_Blob) != 0)
- return 0;
- if ((pMem->flags & MEM_Str) != 0) {
- MemSetTypeFlag(pMem, MEM_Str);
- return 0;
- }
- return -1;
- default:
- assert(type == FIELD_TYPE_STRING);
- assert(MEM_Str == (MEM_Blob >> 3));
- if ((pMem->flags & MEM_Bool) != 0) {
- const char *str_bool = SQL_TOKEN_BOOLEAN(pMem->u.b);
- if (mem_copy_str0(pMem, str_bool) != 0)
- return -1;
- return 0;
- }
- pMem->flags |= (pMem->flags & MEM_Blob) >> 3;
- sql_value_apply_type(pMem, FIELD_TYPE_STRING);
- assert(pMem->flags & MEM_Str || pMem->db->mallocFailed);
- pMem->flags &=
- ~(MEM_Int | MEM_UInt | MEM_Real | MEM_Blob | MEM_Zero);
- return 0;
- }
-}
-
/*
* Make sure the given Mem is \u0000 terminated.
*/
@@ -2282,43 +2264,6 @@ mem_apply_type(struct Mem *record, enum field_type type)
}
}
-/**
- * Convert the numeric value contained in MEM to unsigned.
- *
- * @param mem The MEM that contains the numeric value.
- * @retval 0 if the conversion was successful, -1 otherwise.
- */
-static int
-mem_convert_to_unsigned(struct Mem *mem)
-{
- if ((mem->flags & MEM_UInt) != 0)
- return 0;
- if ((mem->flags & MEM_Int) != 0)
- return -1;
- if ((mem->flags & MEM_Real) == 0)
- return -1;
- double d = mem->u.r;
- if (d < 0.0 || d >= (double)UINT64_MAX)
- return -1;
- mem->u.u = (uint64_t)d;
- mem->flags = MEM_UInt;
- mem->field_type = FIELD_TYPE_UNSIGNED;
- return 0;
-}
-
-int
-mem_convert_to_numeric(struct Mem *mem, enum field_type type)
-{
- assert(mem_is_num(mem) && sql_type_is_numeric(type));
- assert(type != FIELD_TYPE_NUMBER);
- if (type == FIELD_TYPE_DOUBLE)
- return mem_to_double(mem);
- if (type == FIELD_TYPE_UNSIGNED)
- return mem_convert_to_unsigned(mem);
- assert(type == FIELD_TYPE_INTEGER);
- return mem_to_int(mem);
-}
-
static int
sqlVdbeMemGrow(struct Mem *pMem, int n, int bPreserve)
{
diff --git a/src/box/sql/mem.h b/src/box/sql/mem.h
index 146d08a2a..73d2ffd6a 100644
--- a/src/box/sql/mem.h
+++ b/src/box/sql/mem.h
@@ -522,6 +522,10 @@ mem_to_str(struct Mem *mem);
int
mem_to_str0(struct Mem *mem);
+/** Convert the given MEM to given type according to explicit cast rules. */
+int
+mem_cast_explicit(struct Mem *mem, enum field_type type);
+
/**
* Simple type to str convertor. It is used to simplify
* error reporting.
@@ -555,7 +559,6 @@ registerTrace(int iReg, Mem *p);
#define memIsValid(M) !mem_is_invalid(M)
#endif
-int sqlVdbeMemCast(struct Mem *, enum field_type type);
int sqlVdbeMemNulTerminate(struct Mem *);
int sqlVdbeMemExpandBlob(struct Mem *);
#define ExpandBlob(P) (mem_is_zerobin(P)? sqlVdbeMemExpandBlob(P) : 0)
@@ -598,17 +601,6 @@ void sql_value_apply_type(struct Mem *val, enum field_type type);
int
mem_apply_type(struct Mem *record, enum field_type type);
-/**
- * Convert the numeric value contained in MEM to another numeric
- * type.
- *
- * @param mem The MEM that contains the numeric value.
- * @param type The type to convert to.
- * @retval 0 if the conversion was successful, -1 otherwise.
- */
-int
-mem_convert_to_numeric(struct Mem *mem, enum field_type type);
-
/** Setters = Change MEM value. */
int sqlVdbeMemClearAndResize(struct Mem * pMem, int n);
@@ -622,12 +614,6 @@ struct Mem *sqlValueNew(struct sql *);
void
releaseMemArray(Mem * p, int N);
-/*
- * Clear any existing type flags from a Mem and replace them with f
- */
-#define MemSetTypeFlag(p, f) \
- ((p)->flags = ((p)->flags&~(MEM_TypeMask|MEM_Zero))|f)
-
/** Getters. */
int
diff --git a/src/box/sql/vdbe.c b/src/box/sql/vdbe.c
index 7880af248..29634841a 100644
--- a/src/box/sql/vdbe.c
+++ b/src/box/sql/vdbe.c
@@ -1480,7 +1480,7 @@ case OP_Cast: { /* in1 */
pIn1 = &aMem[pOp->p1];
if (ExpandBlob(pIn1) != 0)
goto abort_due_to_error;
- rc = sqlVdbeMemCast(pIn1, pOp->p2);
+ rc = mem_cast_explicit(pIn1, pOp->p2);
/*
* SCALAR is not type itself, but rather an aggregation
* of types. Hence, cast to this type shouldn't change
@@ -2100,7 +2100,7 @@ case OP_ApplyType: {
if (!mem_is_num(pIn1))
goto type_mismatch;
/* Try to convert numeric-to-numeric. */
- if (mem_convert_to_numeric(pIn1, type) != 0)
+ if (mem_cast_explicit(pIn1, type) != 0)
goto type_mismatch;
}
pIn1++;
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