[Tarantool-patches] [PATCH v5 15/52] sql: rework mem_move()
Mergen Imeev
imeevma at tarantool.org
Tue Apr 13 19:38:25 MSK 2021
Thank you for the review! My answer, diff and new patch below.
On Sun, Apr 11, 2021 at 08:10:50PM +0200, Vladislav Shpilevoy wrote:
> I appreciate the work you did here!
>
> On 09.04.2021 19:37, Mergen Imeev via Tarantool-patches wrote:
> > This patch reworks mem_move(). This function moves all content of source
> > MEM to destination MEM. Source mem is set to NULL.
> >
> > Part of #5818
> > ---
> > src/box/sql/mem.c | 57 +++++++++----------------------------------
> > src/box/sql/mem.h | 8 ++++--
> > src/box/sql/vdbe.c | 23 +----------------
> > src/box/sql/vdbeapi.c | 2 +-
> > 4 files changed, 19 insertions(+), 71 deletions(-)
> >
> > diff --git a/src/box/sql/mem.c b/src/box/sql/mem.c
> > index f75661e04..d56fe56c6 100644
> > --- a/src/box/sql/mem.c
> > +++ b/src/box/sql/mem.c
> > @@ -315,6 +315,17 @@ mem_copy_as_ephemeral(struct Mem *to, const struct Mem *from)
> > return;
> > }
> >
> > +int
>
> It can be 'void'. The function never fails.
>
Fixed.
> > +mem_move(struct Mem *to, struct Mem *from)
> > +{
> > + mem_destroy(to);
> > + memcpy(to, from, sizeof(*to));
> > + from->flags = MEM_Null;
> > + from->szMalloc = 0;
> > + from->zMalloc = NULL;
> > + return 0;
> > +}
Diff:
diff --git a/src/box/sql/mem.c b/src/box/sql/mem.c
index f583dc7c0..2991f902d 100644
--- a/src/box/sql/mem.c
+++ b/src/box/sql/mem.c
@@ -170,7 +170,7 @@ mem_copy_as_ephemeral(struct Mem *to, const struct Mem *from)
return;
}
-int
+void
mem_move(struct Mem *to, struct Mem *from)
{
mem_destroy(to);
@@ -178,7 +178,6 @@ mem_move(struct Mem *to, struct Mem *from)
from->flags = MEM_Null;
from->szMalloc = 0;
from->zMalloc = NULL;
- return 0;
}
static inline bool
diff --git a/src/box/sql/mem.h b/src/box/sql/mem.h
index 496fef1e3..beb9826a1 100644
--- a/src/box/sql/mem.h
+++ b/src/box/sql/mem.h
@@ -319,7 +319,7 @@ mem_copy_as_ephemeral(struct Mem *to, const struct Mem *from);
/**
* Move all content of source MEM to destination MEM. Source MEM is set to NULL.
*/
-int
+void
mem_move(struct Mem *to, struct Mem *from);
/**
New patch:
commit e54a891eebb0ae9af9cde630628a5cdb03e00698
Author: Mergen Imeev <imeevma at gmail.com>
Date: Fri Mar 5 15:30:23 2021 +0300
sql: rework mem_move()
This patch reworks mem_move(). This function moves all content of source
MEM to destination MEM. Source mem is set to NULL.
Part of #5818
diff --git a/src/box/sql/mem.c b/src/box/sql/mem.c
index befedf04c..2991f902d 100644
--- a/src/box/sql/mem.c
+++ b/src/box/sql/mem.c
@@ -170,6 +170,16 @@ mem_copy_as_ephemeral(struct Mem *to, const struct Mem *from)
return;
}
+void
+mem_move(struct Mem *to, struct Mem *from)
+{
+ mem_destroy(to);
+ memcpy(to, from, sizeof(*to));
+ from->flags = MEM_Null;
+ from->szMalloc = 0;
+ from->zMalloc = NULL;
+}
+
static inline bool
mem_has_msgpack_subtype(struct Mem *mem)
{
@@ -1849,52 +1859,6 @@ vdbe_mem_alloc_blob_region(struct Mem *vdbe_mem, uint32_t size)
return 0;
}
-/*
- * Transfer the contents of pFrom to pTo. Any existing value in pTo is
- * freed. If pFrom contains ephemeral data, a copy is made.
- *
- * pFrom contains an SQL NULL when this routine returns.
- */
-void
-sqlVdbeMemMove(Mem * pTo, Mem * pFrom)
-{
- assert(pFrom->db == 0 || pTo->db == 0 || pFrom->db == pTo->db);
-
- mem_destroy(pTo);
- memcpy(pTo, pFrom, sizeof(Mem));
- pFrom->flags = MEM_Null;
- pFrom->szMalloc = 0;
-}
-
-/*
- * Change pMem so that its MEM_Str or MEM_Blob value is stored in
- * MEM.zMalloc, where it can be safely written.
- *
- * Return 0 on success or -1 if malloc fails.
- */
-int
-sqlVdbeMemMakeWriteable(Mem * pMem)
-{
- if ((pMem->flags & (MEM_Str | MEM_Blob)) != 0) {
- if (ExpandBlob(pMem))
- return -1;
- if (pMem->szMalloc == 0 || pMem->z != pMem->zMalloc) {
- if (sqlVdbeMemGrow(pMem, pMem->n + 2, 1)) {
- return -1;
- }
- pMem->z[pMem->n] = 0;
- pMem->z[pMem->n + 1] = 0;
- pMem->flags |= MEM_Term;
- }
- }
- pMem->flags &= ~MEM_Ephem;
-#ifdef SQL_DEBUG
- pMem->pScopyFrom = 0;
-#endif
-
- return 0;
-}
-
int
sql_vdbemem_finalize(struct Mem *mem, struct func *func)
{
diff --git a/src/box/sql/mem.h b/src/box/sql/mem.h
index e30e5466e..beb9826a1 100644
--- a/src/box/sql/mem.h
+++ b/src/box/sql/mem.h
@@ -316,6 +316,12 @@ mem_copy(struct Mem *to, const struct Mem *from);
void
mem_copy_as_ephemeral(struct Mem *to, const struct Mem *from);
+/**
+ * Move all content of source MEM to destination MEM. Source MEM is set to NULL.
+ */
+void
+mem_move(struct Mem *to, struct Mem *from);
+
/**
* Simple type to str convertor. It is used to simplify
* error reporting.
@@ -563,8 +569,6 @@ mem_is_type_compatible(struct Mem *mem, enum field_type type);
int
vdbe_mem_alloc_blob_region(struct Mem *vdbe_mem, uint32_t size);
-void sqlVdbeMemMove(Mem *, Mem *);
-int sqlVdbeMemMakeWriteable(Mem *);
/**
* Memory cell mem contains the context of an aggregate function.
diff --git a/src/box/sql/vdbe.c b/src/box/sql/vdbe.c
index 50d9dd78c..b3b20a374 100644
--- a/src/box/sql/vdbe.c
+++ b/src/box/sql/vdbe.c
@@ -197,21 +197,6 @@ vdbeTakeBranch(int iSrcLine, u8 I, u8 M)
}
#endif
-/*
- * An ephemeral string value (signified by the MEM_Ephem flag) contains
- * a pointer to a dynamically allocated string where some other entity
- * is responsible for deallocating that string. Because the register
- * does not control the string, it might be deleted without the register
- * knowing it.
- *
- * This routine converts an ephemeral string into a dynamically allocated
- * string that the register itself controls. In other words, it
- * converts an MEM_Ephem string into a string with P.z==P.zMalloc.
- */
-#define Deephemeralize(P) \
- if (((P)->flags&MEM_Ephem)!=0 \
- && sqlVdbeMemMakeWriteable(P)) { goto no_mem;}
-
/* Return true if the cursor was opened using the OP_OpenSorter opcode. */
#define isSorter(x) ((x)->eCurType==CURTYPE_SORTER)
@@ -981,13 +966,7 @@ case OP_Move: {
assert(pIn1<=&aMem[(p->nMem+1 - p->nCursor)]);
assert(memIsValid(pIn1));
memAboutToChange(p, pOut);
- sqlVdbeMemMove(pOut, pIn1);
-#ifdef SQL_DEBUG
- if (pOut->pScopyFrom>=&aMem[p1] && pOut->pScopyFrom<pOut) {
- pOut->pScopyFrom += pOp->p2 - p1;
- }
-#endif
- Deephemeralize(pOut);
+ mem_move(pOut, pIn1);
REGISTER_TRACE(p, p2++, pOut);
pIn1++;
pOut++;
diff --git a/src/box/sql/vdbeapi.c b/src/box/sql/vdbeapi.c
index 7951996ea..8e69e3c38 100644
--- a/src/box/sql/vdbeapi.c
+++ b/src/box/sql/vdbeapi.c
@@ -980,7 +980,7 @@ sqlTransferBindings(sql_stmt * pFromStmt, sql_stmt * pToStmt)
assert(pTo->db == pFrom->db);
assert(pTo->nVar == pFrom->nVar);
for (i = 0; i < pFrom->nVar; i++) {
- sqlVdbeMemMove(&pTo->aVar[i], &pFrom->aVar[i]);
+ mem_move(&pTo->aVar[i], &pFrom->aVar[i]);
}
return 0;
}
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