Re: [Tarantool-patches] [PATCH v5 27/52] sql: introduce mem_set_str_*() functions

[Mergen Imeev via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

Thank you for the review! My answers, diff and new patch below.


On Tue, Apr 13, 2021 at 01:34:22AM +0200, Vladislav Shpilevoy wrote:
> Nice fixes!
> 
> See 2 comments below.
> 
> > diff --git a/src/box/sql/vdbeapi.c b/src/box/sql/vdbeapi.c
> > index 6c08e772d..e0903e3b0 100644
> > --- a/src/box/sql/vdbeapi.c
> > +++ b/src/box/sql/vdbeapi.c
> > @@ -125,6 +125,27 @@ setResultStrOrError(sql_context * pCtx,	/* Function context */
> >  		    void (*xDel) (void *)	/* Destructor function */
> >      )
> >  {
> > +	if (xDel == SQL_STATIC) {
> > +		if (n < 0)
> > +			mem_set_str0_static(pCtx->pOut, (char *)z);
> > +		else
> > +			mem_set_str_static(pCtx->pOut, (char *)z, n);
> > +		return;
> > +	}
> > +	if (xDel == SQL_DYNAMIC) {
> > +		if (n < 0)
> > +			mem_set_str0_allocated(pCtx->pOut, (char *)z);
> > +		else
> > +			mem_set_str_allocated(pCtx->pOut, (char *)z, n);
> 
> 1. I don't understand. You check for xDel == SQL_DYNAMIC and yet
> you use 'allocated' suffix. Below you check for != TRANSIENT
> instead of == DYNAMIC, and use 'dynamic'. Why? All looks messed
> up. The same in the next hunk.
> 
This is how it worked in sqlValueSetStr(). xDel == SQL_DYNAMIC (which is
actually == sqlMallocSize) was used to show that this value should be set as
allocated memory; xDel == SQL_TRANSIENT (== -1) was used to show that value
should be copied; xDel == SQL_STATIC (== 0) for MEM_Static and in case it some
other functions it was treated as free() for given memory, i.e. MEM_Dyn.

> > +		return;
> > +	}> diff --git a/src/box/sql/vdbeaux.c b/src/box/sql/vdbeaux.c
> > index ae55e4c29..171cb8946 100644
> > --- a/src/box/sql/vdbeaux.c
> > +++ b/src/box/sql/vdbeaux.c
> > @@ -1333,41 +1331,34 @@ sqlVdbeList(Vdbe * p)
> >  		mem_set_int(pMem, pOp->p3, pOp->p3 < 0);
> >  		pMem++;
> >  
> > -		if (sqlVdbeMemClearAndResize(pMem, 256)) {
> > -			assert(p->db->mallocFailed);
> > +		char *buf = sqlDbMallocRaw(sql_get(), 256);
> 
> 2. I think you need some kind of mem_set_strlen(), or mem_grow()/mem_reserve(),
> or something else to reserve the memory. To extend zMalloc. Otherwise you
> can't reuse the memory which might already be in the mem object.
Wouldn't mem_copy_*() be enough? In general, allocated by MEM memory should not
be accessed for changing (except for MEM_Agg).


Diff:


diff --git a/src/box/sql/mem.h b/src/box/sql/mem.h
index d8e640810..f029ee0e5 100644
--- a/src/box/sql/mem.h
+++ b/src/box/sql/mem.h
@@ -373,6 +373,42 @@ mem_set_str0_dynamic(struct Mem *mem, char *value);
 void
 mem_set_str0_allocated(struct Mem *mem, char *value);
 
+static inline void
+mem_set_strl_ephemeral(struct Mem *mem, char *value, int len_hint)
+{
+	if (len_hint < 0)
+		mem_set_str0_ephemeral(mem, value);
+	else
+		mem_set_str_ephemeral(mem, value, len_hint);
+}
+
+static inline void
+mem_set_strl_static(struct Mem *mem, char *value, int len_hint)
+{
+	if (len_hint < 0)
+		mem_set_str0_static(mem, value);
+	else
+		mem_set_str_static(mem, value, len_hint);
+}
+
+static inline void
+mem_set_strl_dynamic(struct Mem *mem, char *value, int len_hint)
+{
+	if (len_hint < 0)
+		mem_set_str0_dynamic(mem, value);
+	else
+		mem_set_str_dynamic(mem, value, len_hint);
+}
+
+static inline void
+mem_set_strl_allocated(struct Mem *mem, char *value, int len_hint)
+{
+	if (len_hint < 0)
+		mem_set_str0_allocated(mem, value);
+	else
+		mem_set_str_allocated(mem, value, len_hint);
+}
+
 /**
  * Copy content of MEM from one MEM to another. In case source MEM contains
  * string or binary and allocation type is not STATIC, this value is copied to
diff --git a/src/box/sql/vdbeapi.c b/src/box/sql/vdbeapi.c
index e0903e3b0..484c66b29 100644
--- a/src/box/sql/vdbeapi.c
+++ b/src/box/sql/vdbeapi.c
@@ -125,27 +125,12 @@ setResultStrOrError(sql_context * pCtx,	/* Function context */
 		    void (*xDel) (void *)	/* Destructor function */
     )
 {
-	if (xDel == SQL_STATIC) {
-		if (n < 0)
-			mem_set_str0_static(pCtx->pOut, (char *)z);
-		else
-			mem_set_str_static(pCtx->pOut, (char *)z, n);
-		return;
-	}
-	if (xDel == SQL_DYNAMIC) {
-		if (n < 0)
-			mem_set_str0_allocated(pCtx->pOut, (char *)z);
-		else
-			mem_set_str_allocated(pCtx->pOut, (char *)z, n);
-		return;
-	}
-	if (xDel != SQL_TRANSIENT) {
-		if (n < 0)
-			mem_set_str0_dynamic(pCtx->pOut, (char *)z);
-		else
-			mem_set_str_dynamic(pCtx->pOut, (char *)z, n);
-		return;
-	}
+	if (xDel == SQL_STATIC)
+		return mem_set_strl_static(pCtx->pOut, (char *)z, n);
+	if (xDel == SQL_DYNAMIC)
+		return mem_set_strl_allocated(pCtx->pOut, (char *)z, n);
+	if (xDel != SQL_TRANSIENT)
+		return mem_set_strl_dynamic(pCtx->pOut, (char *)z, n);
 	if (sqlVdbeMemSetStr(pCtx->pOut, z, n, 1, xDel) != 0)
 		pCtx->is_aborted = true;
 }
@@ -783,24 +768,14 @@ bindText(sql_stmt * pStmt,	/* The statement to bind against */
 	if (zData == NULL)
 		return 0;
 	pVar = &p->aVar[i - 1];
-	if (xDel == SQL_STATIC) {
-		if (nData < 0)
-			mem_set_str0_static(pVar, (char *)zData);
-		else
-			mem_set_str_static(pVar, (char *)zData, nData);
-	} else if (xDel == SQL_DYNAMIC) {
-		if (nData < 0)
-			mem_set_str0_allocated(pVar, (char *)zData);
-		else
-			mem_set_str_allocated(pVar, (char *)zData, nData);
-	} else if (xDel != SQL_TRANSIENT) {
-		if (nData < 0)
-			mem_set_str0_dynamic(pVar, (char *)zData);
-		else
-			mem_set_str_dynamic(pVar, (char *)zData, nData);
-	} else if (sqlVdbeMemSetStr(pVar, zData, nData, 1, xDel) != 0) {
+	if (xDel == SQL_STATIC)
+		mem_set_strl_static(pVar, (char *)zData, nData);
+	else if (xDel == SQL_DYNAMIC)
+		mem_set_strl_allocated(pVar, (char *)zData, nData);
+	else if (xDel != SQL_TRANSIENT)
+		mem_set_strl_dynamic(pVar, (char *)zData, nData);
+	else if (sqlVdbeMemSetStr(pVar, zData, nData, 1, xDel) != 0)
 		return -1;
-	}
 	return sql_bind_type(p, i, "text");
 }
 


New patch:


commit 33b35f0b1d8578f99af39d509ac1bdf9abc458cc
Author: Mergen Imeev <imeevma@gmail.com>
Date:   Mon Mar 15 14:28:29 2021 +0300

    sql: introduce mem_set_str_*() functions
    
    This patch introduces set of mem_set_str_*() functions. These functions
    clears MEM and sets it to given string value. Degree of clearing and
    type of allocation of the string is determined by the function used.
    
    Part of #5818

diff --git a/src/box/sql/mem.c b/src/box/sql/mem.c
index 683094599..5cf067453 100644
--- a/src/box/sql/mem.c
+++ b/src/box/sql/mem.c
@@ -169,6 +169,89 @@ mem_set_double(struct Mem *mem, double value)
 	mem->flags = MEM_Real;
 }
 
+static inline void
+set_str_const(struct Mem *mem, char *value, uint32_t len, int alloc_type)
+{
+	assert((alloc_type & (MEM_Static | MEM_Ephem)) != 0);
+	mem_clear(mem);
+	mem->z = value;
+	mem->n = len;
+	mem->flags = MEM_Str | alloc_type;
+	mem->field_type = FIELD_TYPE_STRING;
+}
+
+static inline void
+set_str_dynamic(struct Mem *mem, char *value, uint32_t len, int alloc_type)
+{
+	assert((mem->flags & MEM_Dyn) == 0 || value != mem->z);
+	assert(mem->szMalloc == 0 || value != mem->zMalloc);
+	assert(alloc_type == MEM_Dyn || alloc_type == 0);
+	mem_destroy(mem);
+	mem->z = value;
+	mem->n = len;
+	mem->flags = MEM_Str | alloc_type;
+	mem->field_type = FIELD_TYPE_STRING;
+	if (alloc_type == MEM_Dyn) {
+		mem->xDel = sql_free;
+	} else {
+		mem->xDel = NULL;
+		mem->zMalloc = mem->z;
+		mem->szMalloc = sqlDbMallocSize(mem->db, mem->zMalloc);
+	}
+}
+
+void
+mem_set_str_ephemeral(struct Mem *mem, char *value, uint32_t len)
+{
+	set_str_const(mem, value, len, MEM_Ephem);
+}
+
+void
+mem_set_str_static(struct Mem *mem, char *value, uint32_t len)
+{
+	set_str_const(mem, value, len, MEM_Static);
+}
+
+void
+mem_set_str_dynamic(struct Mem *mem, char *value, uint32_t len)
+{
+	set_str_dynamic(mem, value, len, MEM_Dyn);
+}
+
+void
+mem_set_str_allocated(struct Mem *mem, char *value, uint32_t len)
+{
+	set_str_dynamic(mem, value, len, 0);
+}
+
+void
+mem_set_str0_ephemeral(struct Mem *mem, char *value)
+{
+	set_str_const(mem, value, strlen(value), MEM_Ephem);
+	mem->flags |= MEM_Term;
+}
+
+void
+mem_set_str0_static(struct Mem *mem, char *value)
+{
+	set_str_const(mem, value, strlen(value), MEM_Static);
+	mem->flags |= MEM_Term;
+}
+
+void
+mem_set_str0_dynamic(struct Mem *mem, char *value)
+{
+	set_str_dynamic(mem, value, strlen(value), MEM_Dyn);
+	mem->flags |= MEM_Term;
+}
+
+void
+mem_set_str0_allocated(struct Mem *mem, char *value)
+{
+	set_str_dynamic(mem, value, strlen(value), 0);
+	mem->flags |= MEM_Term;
+}
+
 int
 mem_copy(struct Mem *to, const struct Mem *from)
 {
@@ -1908,20 +1991,6 @@ sqlVdbeMemSetZeroBlob(Mem * pMem, int n)
 	pMem->z = 0;
 }
 
-/*
- * Change the string value of an sql_value object
- */
-void
-sqlValueSetStr(sql_value * v,	/* Value to be set */
-		   int n,	/* Length of string z */
-		   const void *z,	/* Text of the new string */
-		   void (*xDel) (void *)	/* Destructor for the string */
-    )
-{
-	if (v)
-		sqlVdbeMemSetStr((Mem *) v, z, n, 1, xDel);
-}
-
 /*
  * Free an sql_value object
  */
diff --git a/src/box/sql/mem.h b/src/box/sql/mem.h
index d573487b0..f029ee0e5 100644
--- a/src/box/sql/mem.h
+++ b/src/box/sql/mem.h
@@ -320,6 +320,95 @@ mem_set_bool(struct Mem *mem, bool value);
 void
 mem_set_double(struct Mem *mem, double value);
 
+/** Clear MEM and set it to STRING. The string belongs to another object. */
+void
+mem_set_str_ephemeral(struct Mem *mem, char *value, uint32_t len);
+
+/** Clear MEM and set it to STRING. The string is static. */
+void
+mem_set_str_static(struct Mem *mem, char *value, uint32_t len);
+
+/**
+ * Clear MEM and set it to STRING. The string was allocated by another object
+ * and passed to MEM. MEMs with this allocation type must free given memory
+ * whenever the MEM changes.
+ */
+void
+mem_set_str_dynamic(struct Mem *mem, char *value, uint32_t len);
+
+/**
+ * Clear MEM and set it to STRING. The string was allocated by another object
+ * and passed to MEM. MEMs with this allocation type only deallocate the string
+ * on destruction. Also, the memory may be reallocated if MEM is set to a
+ * different value of this allocation type.
+ */
+void
+mem_set_str_allocated(struct Mem *mem, char *value, uint32_t len);
+
+/**
+ * Clear MEM and set it to NULL-terminated STRING. The string belongs to
+ * another object.
+ */
+void
+mem_set_str0_ephemeral(struct Mem *mem, char *value);
+
+/** Clear MEM and set it to NULL-terminated STRING. The string is static. */
+void
+mem_set_str0_static(struct Mem *mem, char *value);
+
+/**
+ * Clear MEM and set it to NULL-terminated STRING. The string was allocated by
+ * another object and passed to MEM. MEMs with this allocation type must free
+ * given memory whenever the MEM changes.
+ */
+void
+mem_set_str0_dynamic(struct Mem *mem, char *value);
+
+/**
+ * Clear MEM and set it to NULL-terminated STRING. The string was allocated by
+ * another object and passed to MEM. MEMs with this allocation type only
+ * deallocate the string on destruction. Also, the memory may be reallocated if
+ * MEM is set to a different value of this allocation type.
+ */
+void
+mem_set_str0_allocated(struct Mem *mem, char *value);
+
+static inline void
+mem_set_strl_ephemeral(struct Mem *mem, char *value, int len_hint)
+{
+	if (len_hint < 0)
+		mem_set_str0_ephemeral(mem, value);
+	else
+		mem_set_str_ephemeral(mem, value, len_hint);
+}
+
+static inline void
+mem_set_strl_static(struct Mem *mem, char *value, int len_hint)
+{
+	if (len_hint < 0)
+		mem_set_str0_static(mem, value);
+	else
+		mem_set_str_static(mem, value, len_hint);
+}
+
+static inline void
+mem_set_strl_dynamic(struct Mem *mem, char *value, int len_hint)
+{
+	if (len_hint < 0)
+		mem_set_str0_dynamic(mem, value);
+	else
+		mem_set_str_dynamic(mem, value, len_hint);
+}
+
+static inline void
+mem_set_strl_allocated(struct Mem *mem, char *value, int len_hint)
+{
+	if (len_hint < 0)
+		mem_set_str0_allocated(mem, value);
+	else
+		mem_set_str_allocated(mem, value, len_hint);
+}
+
 /**
  * Copy content of MEM from one MEM to another. In case source MEM contains
  * string or binary and allocation type is not STATIC, this value is copied to
@@ -578,8 +667,6 @@ int
 sqlVdbeMemSetStr(struct Mem *, const char *, int, u8, void (*)(void *));
 void
 sqlVdbeMemSetZeroBlob(struct Mem *, int);
-void sqlValueSetStr(struct Mem *, int, const void *,
-			void (*)(void *));
 void sqlValueFree(struct Mem *);
 struct Mem *sqlValueNew(struct sql *);
 
diff --git a/src/box/sql/sqlInt.h b/src/box/sql/sqlInt.h
index 259ba3833..7a026d21b 100644
--- a/src/box/sql/sqlInt.h
+++ b/src/box/sql/sqlInt.h
@@ -641,10 +641,6 @@ sql_bind_uint64(struct sql_stmt *stmt, int i, uint64_t value);
 int
 sql_bind_null(sql_stmt *, int);
 
-int
-sql_bind_text(sql_stmt *, int, const char *, int,
-		  void (*)(void *));
-
 int
 sql_bind_text64(sql_stmt *, int, const char *,
 		    sql_uint64, void (*)(void *));
diff --git a/src/box/sql/vdbe.c b/src/box/sql/vdbe.c
index 84704b9d0..d7f01000a 100644
--- a/src/box/sql/vdbe.c
+++ b/src/box/sql/vdbe.c
@@ -841,9 +841,8 @@ case OP_String8: {         /* same as TK_STRING, out2 */
 case OP_String: {          /* out2 */
 	assert(pOp->p4.z!=0);
 	pOut = vdbe_prepare_null_out(p, pOp->p2);
-	pOut->flags = MEM_Str|MEM_Static|MEM_Term;
-	pOut->z = pOp->p4.z;
-	pOut->n = pOp->p1;
+	assert(strlen(pOp->p4.z) == (size_t)pOp->p1);
+	mem_set_str0_static(pOut, pOp->p4.z);
 	UPDATE_MAX_BLOBSIZE(pOut);
 	break;
 }
diff --git a/src/box/sql/vdbeapi.c b/src/box/sql/vdbeapi.c
index 6c08e772d..484c66b29 100644
--- a/src/box/sql/vdbeapi.c
+++ b/src/box/sql/vdbeapi.c
@@ -125,6 +125,12 @@ setResultStrOrError(sql_context * pCtx,	/* Function context */
 		    void (*xDel) (void *)	/* Destructor function */
     )
 {
+	if (xDel == SQL_STATIC)
+		return mem_set_strl_static(pCtx->pOut, (char *)z, n);
+	if (xDel == SQL_DYNAMIC)
+		return mem_set_strl_allocated(pCtx->pOut, (char *)z, n);
+	if (xDel != SQL_TRANSIENT)
+		return mem_set_strl_dynamic(pCtx->pOut, (char *)z, n);
 	if (sqlVdbeMemSetStr(pCtx->pOut, z, n, 1, xDel) != 0)
 		pCtx->is_aborted = true;
 }
@@ -762,7 +768,13 @@ bindText(sql_stmt * pStmt,	/* The statement to bind against */
 	if (zData == NULL)
 		return 0;
 	pVar = &p->aVar[i - 1];
-	if (sqlVdbeMemSetStr(pVar, zData, nData, 1, xDel) != 0)
+	if (xDel == SQL_STATIC)
+		mem_set_strl_static(pVar, (char *)zData, nData);
+	else if (xDel == SQL_DYNAMIC)
+		mem_set_strl_allocated(pVar, (char *)zData, nData);
+	else if (xDel != SQL_TRANSIENT)
+		mem_set_strl_dynamic(pVar, (char *)zData, nData);
+	else if (sqlVdbeMemSetStr(pVar, zData, nData, 1, xDel) != 0)
 		return -1;
 	return sql_bind_type(p, i, "text");
 }
@@ -876,14 +888,6 @@ sql_bind_ptr(struct sql_stmt *stmt, int i, void *ptr)
 	return rc;
 }
 
-int
-sql_bind_text(sql_stmt * pStmt,
-		  int i, const char *zData, int nData, void (*xDel) (void *)
-    )
-{
-	return bindText(pStmt, i, zData, nData, xDel);
-}
-
 int
 sql_bind_text64(sql_stmt * pStmt,
 		    int i,
diff --git a/src/box/sql/vdbeaux.c b/src/box/sql/vdbeaux.c
index c8ec7f4fa..dad9cab03 100644
--- a/src/box/sql/vdbeaux.c
+++ b/src/box/sql/vdbeaux.c
@@ -1295,10 +1295,8 @@ sqlVdbeList(Vdbe * p)
 
 			pMem++;
 
-			pMem->flags = MEM_Static | MEM_Str | MEM_Term;
-			pMem->z = (char *)sqlOpcodeName(pOp->opcode);	/* Opcode */
-			assert(pMem->z != 0);
-			pMem->n = sqlStrlen30(pMem->z);
+			char *value = (char *)sqlOpcodeName(pOp->opcode);
+			mem_set_str0_static(pMem, value);
 			pMem++;
 
 			/* When an OP_Program opcode is encounter (the only opcode that has
@@ -1333,41 +1331,34 @@ sqlVdbeList(Vdbe * p)
 		mem_set_int(pMem, pOp->p3, pOp->p3 < 0);
 		pMem++;
 
-		if (sqlVdbeMemClearAndResize(pMem, 256)) {
-			assert(p->db->mallocFailed);
+		char *buf = sqlDbMallocRaw(sql_get(), 256);
+		if (buf == NULL)
 			return -1;
-		}
-		pMem->flags = MEM_Str | MEM_Term;
-		zP4 = displayP4(pOp, pMem->z, pMem->szMalloc);
-
-		if (zP4 != pMem->z) {
-			pMem->n = 0;
-			sqlVdbeMemSetStr(pMem, zP4, -1, 1, 0);
+		zP4 = displayP4(pOp, buf, sqlDbMallocSize(sql_get(), buf));
+		if (zP4 != buf) {
+			sqlDbFree(sql_get(), buf);
+			mem_set_str0_ephemeral(pMem, zP4);
 		} else {
-			assert(pMem->z != 0);
-			pMem->n = sqlStrlen30(pMem->z);
+			mem_set_str0_allocated(pMem, zP4);
 		}
 		pMem++;
 
 		if (p->explain == 1) {
-			if (sqlVdbeMemClearAndResize(pMem, 4)) {
-				assert(p->db->mallocFailed);
+			buf = sqlDbMallocRaw(sql_get(), 4);
+			if (buf == NULL)
 				return -1;
-			}
-			pMem->flags = MEM_Str | MEM_Term;
-			pMem->n = 2;
-			sql_snprintf(3, pMem->z, "%.2x", pOp->p5);	/* P5 */
+			sql_snprintf(3, buf, "%.2x", pOp->p5);
+			mem_set_str0_allocated(pMem, buf);
 			pMem++;
 
 #ifdef SQL_ENABLE_EXPLAIN_COMMENTS
-			if (sqlVdbeMemClearAndResize(pMem, 500)) {
-				assert(p->db->mallocFailed);
+			buf = sqlDbMallocRaw(sql_get(), 500);
+			if (buf == NULL)
 				return -1;
-			}
-			pMem->flags = MEM_Str | MEM_Term;
-			pMem->n = displayComment(pOp, zP4, pMem->z, 500);
+			displayComment(pOp, zP4, buf, 500);
+			mem_set_str0_allocated(pMem, buf);
 #else
-			pMem->flags = MEM_Null;	/* Comment */
+			mem_set_null(pMem);
 #endif
 		}