[Tarantool-patches] [PATCH v4 12/53] sql: introduce mem_copy()

[imeevma at tarantool.org]

This patch introduces mem_copy(). This function copies value from source
MEM to destination MEM. In case value is string or binary and have not
static allocation type, it is copied to newly allocated memory.

Part of #5818
---
 src/box/sql/func.c    |  4 ++--
 src/box/sql/mem.c     | 54 +++++++++++++++++++++++++------------------
 src/box/sql/mem.h     |  9 +++++++-
 src/box/sql/vdbeapi.c |  2 +-
 src/box/sql/vdbeaux.c |  2 +-
 5 files changed, 44 insertions(+), 27 deletions(-)

diff --git a/src/box/sql/func.c b/src/box/sql/func.c
index 81b537d9b..6b6081150 100644
--- a/src/box/sql/func.c
+++ b/src/box/sql/func.c
@@ -2079,13 +2079,13 @@ minmaxStep(sql_context * context, int NotUsed, sql_value ** argv)
 		bool is_max = (func->flags & SQL_FUNC_MAX) != 0;
 		cmp = sqlMemCompare(pBest, pArg, pColl);
 		if ((is_max && cmp < 0) || (!is_max && cmp > 0)) {
-			sqlVdbeMemCopy(pBest, pArg);
+			mem_copy(pBest, pArg);
 		} else {
 			sqlSkipAccumulatorLoad(context);
 		}
 	} else {
 		pBest->db = sql_context_db_handle(context);
-		sqlVdbeMemCopy(pBest, pArg);
+		mem_copy(pBest, pArg);
 	}
 }
 
diff --git a/src/box/sql/mem.c b/src/box/sql/mem.c
index abc9291ef..f12441d7c 100644
--- a/src/box/sql/mem.c
+++ b/src/box/sql/mem.c
@@ -257,6 +257,38 @@ mem_destroy(struct Mem *mem)
 	mem->zMalloc = NULL;
 }
 
+int
+mem_copy(struct Mem *to, const struct Mem *from)
+{
+	mem_clear(to);
+	to->u = from->u;
+	to->flags = from->flags;
+	to->subtype = from->subtype;
+	to->field_type = from->field_type;
+	to->n = from->n;
+	to->z = from->z;
+	if ((to->flags & (MEM_Str | MEM_Blob)) == 0)
+		return 0;
+	if ((to->flags & MEM_Static) != 0)
+		return 0;
+	if ((to->flags & (MEM_Zero | MEM_Blob)) == (MEM_Zero | MEM_Blob)) {
+		if (sqlVdbeMemExpandBlob(to) != 0)
+			return -1;
+		return 0;
+	}
+	if (to->szMalloc == 0)
+		to->zMalloc = sqlDbMallocRaw(to->db, to->n);
+	else
+		to->zMalloc = sqlDbReallocOrFree(to->db, to->zMalloc, to->n);
+	if (to->zMalloc == NULL)
+		return -1;
+	to->szMalloc = sqlDbMallocSize(to->db, to->zMalloc);
+	memcpy(to->zMalloc, to->z, to->n);
+	to->z = to->zMalloc;
+	to->flags &= (MEM_Str | MEM_Blob | MEM_Term | MEM_Subtype);
+	return 0;
+}
+
 static inline bool
 mem_has_msgpack_subtype(struct Mem *mem)
 {
@@ -1993,28 +2025,6 @@ vdbe_mem_alloc_blob_region(struct Mem *vdbe_mem, uint32_t size)
 	return 0;
 }
 
-/*
- * Make a full copy of pFrom into pTo.  Prior contents of pTo are
- * freed before the copy is made.
- */
-int
-sqlVdbeMemCopy(Mem * pTo, const Mem * pFrom)
-{
-	int rc = 0;
-
-	mem_clear(pTo);
-	memcpy(pTo, pFrom, MEMCELLSIZE);
-	pTo->flags &= ~MEM_Dyn;
-	if (pTo->flags & (MEM_Str | MEM_Blob)) {
-		if (0 == (pFrom->flags & MEM_Static)) {
-			pTo->flags |= MEM_Ephem;
-			rc = sqlVdbeMemMakeWriteable(pTo);
-		}
-	}
-
-	return rc;
-}
-
 void
 sqlVdbeMemShallowCopy(Mem * pTo, const Mem * pFrom, int srcType)
 {
diff --git a/src/box/sql/mem.h b/src/box/sql/mem.h
index 19920af3a..fb649891a 100644
--- a/src/box/sql/mem.h
+++ b/src/box/sql/mem.h
@@ -169,6 +169,14 @@ mem_create(struct Mem *mem);
 void
 mem_destroy(struct Mem *mem);
 
+/**
+ * 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
+ * newly allocated by destination MEM memory.
+ */
+int
+mem_copy(struct Mem *to, const struct Mem *from);
+
 /* One or more of the following flags are set to indicate the validOK
  * representations of the value stored in the Mem struct.
  *
@@ -485,7 +493,6 @@ mem_is_type_compatible(struct Mem *mem, enum field_type type);
 
 int
 vdbe_mem_alloc_blob_region(struct Mem *vdbe_mem, uint32_t size);
-int sqlVdbeMemCopy(Mem *, const Mem *);
 void sqlVdbeMemShallowCopy(Mem *, const Mem *, int);
 void sqlVdbeMemMove(Mem *, Mem *);
 int sqlVdbeMemMakeWriteable(Mem *);
diff --git a/src/box/sql/vdbeapi.c b/src/box/sql/vdbeapi.c
index 8a9573c57..b13385647 100644
--- a/src/box/sql/vdbeapi.c
+++ b/src/box/sql/vdbeapi.c
@@ -229,7 +229,7 @@ sql_result_text64(sql_context * pCtx,
 void
 sql_result_value(sql_context * pCtx, sql_value * pValue)
 {
-	sqlVdbeMemCopy(pCtx->pOut, pValue);
+	mem_copy(pCtx->pOut, pValue);
 }
 
 void
diff --git a/src/box/sql/vdbeaux.c b/src/box/sql/vdbeaux.c
index 11304b5bc..21ac84099 100644
--- a/src/box/sql/vdbeaux.c
+++ b/src/box/sql/vdbeaux.c
@@ -2309,7 +2309,7 @@ sqlVdbeGetBoundValue(Vdbe * v, int iVar, u8 aff)
 		if (!mem_is_null(pMem)) {
 			sql_value *pRet = sqlValueNew(v->db);
 			if (pRet) {
-				sqlVdbeMemCopy((Mem *) pRet, pMem);
+				mem_copy(pRet, pMem);
 				sql_value_apply_type(pRet, aff);
 			}
 			return pRet;
-- 
2.25.1