[tarantool-patches] [PATCH v2 4/4] sql: remove OP_LoadPtr

[Kirill Shcherbatov <kshcherbatov@tarantool.org>]

From: Vladislav Shpilevoy <v.shpilevoy@tarantool.org>

This opcode was used when Vdbe had to store key_def in P4 for
OP_OpenRead/Write, so P4 was occupied and OP_LoadPtr was used to
store space pointer in another opcode. But now P4 is free for
OpenRead/Write and space pointer can be stored here.

Alongside, some useless key_def duplications are removed.
---
 src/box/sql/analyze.c   |  8 ++----
 src/box/sql/build.c     | 20 +++++----------
 src/box/sql/delete.c    | 15 ++---------
 src/box/sql/insert.c    | 18 +++----------
 src/box/sql/pragma.c    | 39 ++++++++++++++--------------
 src/box/sql/sqliteInt.h |  5 ----
 src/box/sql/vdbe.c      | 68 +++++--------------------------------------------
 7 files changed, 40 insertions(+), 133 deletions(-)

diff --git a/src/box/sql/analyze.c b/src/box/sql/analyze.c
index 067a86e..699a4e8 100644
--- a/src/box/sql/analyze.c
+++ b/src/box/sql/analyze.c
@@ -794,7 +794,6 @@ analyzeOneTable(Parse * pParse,	/* Parser context */
 	int iTabCur;		/* Table cursor */
 	Vdbe *v;		/* The virtual machine being built up */
 	int i;			/* Loop counter */
-	int space_ptr_reg = iMem++;
 	int regStat4 = iMem++;	/* Register to hold Stat4Accum object */
 	int regChng = iMem++;	/* Index of changed index field */
 	int regKey = iMem++;	/* Key argument passed to stat_push() */
@@ -894,11 +893,8 @@ analyzeOneTable(Parse * pParse,	/* Parser context */
 			space_by_id(SQLITE_PAGENO_TO_SPACEID(pIdx->tnum));
 		int idx_id = SQLITE_PAGENO_TO_INDEXID(pIdx->tnum);
 		assert(space != NULL);
-		sqlite3VdbeAddOp4(v, OP_LoadPtr, 0, space_ptr_reg, 0,
-				  (void*)space, P4_SPACEPTR);
-		sqlite3VdbeAddOp3(v, OP_OpenRead, iIdxCur, idx_id,
-				  space_ptr_reg);
-		sql_vdbe_set_p4_key_def(pParse, pIdx);
+		sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, idx_id, 0,
+				  (void *) space, P4_SPACEPTR);
 		VdbeComment((v, "%s", pIdx->zName));
 
 		/* Invoke the stat_init() function. The arguments are:
diff --git a/src/box/sql/build.c b/src/box/sql/build.c
index 5f7a35a..26af0fe 100644
--- a/src/box/sql/build.c
+++ b/src/box/sql/build.c
@@ -1108,12 +1108,8 @@ vdbe_emit_open_cursor(struct Parse *parse_context, int cursor, int index_id,
 		      struct space *space)
 {
 	assert(space != NULL);
-	struct Vdbe *vdbe = parse_context->pVdbe;
-	int space_ptr_reg = ++parse_context->nMem;
-	sqlite3VdbeAddOp4(vdbe, OP_LoadPtr, 0, space_ptr_reg, 0, (void*)space,
-			  P4_SPACEPTR);
-	return sqlite3VdbeAddOp3(vdbe, OP_OpenWrite, cursor, index_id,
-				 space_ptr_reg);
+	return sqlite3VdbeAddOp4(parse_context->pVdbe, OP_OpenWrite, cursor,
+				 index_id, 0, (void *) space, P4_SPACEPTR);
 }
 /*
  * Generate code that will increment the schema cookie.
@@ -2961,7 +2957,6 @@ sql_create_index(struct Parse *parse, struct Token *token,
 		Vdbe *v;
 		char *zStmt;
 		int iCursor = parse->nTab++;
-		int index_space_ptr_reg = parse->nTab++;
 		int iSpaceId, iIndexId, iFirstSchemaCol;
 
 		v = sqlite3GetVdbe(parse);
@@ -2969,12 +2964,9 @@ sql_create_index(struct Parse *parse, struct Token *token,
 			goto exit_create_index;
 
 		sql_set_multi_write(parse, true);
-
-
-		sqlite3VdbeAddOp2(v, OP_SIDtoPtr, BOX_INDEX_ID,
-				  index_space_ptr_reg);
-		sqlite3VdbeAddOp4Int(v, OP_OpenWrite, iCursor, 0,
-				     index_space_ptr_reg, 6);
+		sqlite3VdbeAddOp4(v, OP_OpenWrite, iCursor, 0, 0,
+				  (void *)space_by_id(BOX_INDEX_ID),
+				  P4_SPACEPTR);
 		sqlite3VdbeChangeP5(v, OPFLAG_SEEKEQ);
 
 		/*
@@ -3943,7 +3935,7 @@ vdbe_emit_halt_with_presence_test(struct Parse *parser, int space_id,
 	int cursor = parser->nTab++;
 	vdbe_emit_open_cursor(parser, cursor, index_id, space_by_id(space_id));
 
-	int name_reg = parser->nMem++;
+	int name_reg = ++parser->nMem;
 	int label = sqlite3VdbeAddOp4(v, OP_String8, 0, name_reg, 0, name,
 				      P4_DYNAMIC);
 	sqlite3VdbeAddOp4Int(v, cond_opcode, cursor, label + 3, name_reg, 1);
diff --git a/src/box/sql/delete.c b/src/box/sql/delete.c
index d1c5935..ca1e77d 100644
--- a/src/box/sql/delete.c
+++ b/src/box/sql/delete.c
@@ -335,19 +335,8 @@ sql_table_delete_from(struct Parse *parse, struct SrcList *tab_list,
 				iAddrOnce = sqlite3VdbeAddOp0(v, OP_Once);
 				VdbeCoverage(v);
 			}
-
-			int space_ptr_reg = ++parse->nMem;
-			sqlite3VdbeAddOp4(v, OP_LoadPtr, 0, space_ptr_reg, 0,
-					  (void *)space, P4_SPACEPTR);
-
-			sqlite3VdbeAddOp3(v, OP_OpenWrite, tab_cursor, 0,
-					  space_ptr_reg);
-			struct key_def *def = key_def_dup(pk_def);
-			if (def == NULL) {
-				sqlite3OomFault(parse->db);
-				goto delete_from_cleanup;
-			}
-			sqlite3VdbeAppendP4(v, def, P4_KEYDEF);
+			sqlite3VdbeAddOp4(v, OP_OpenWrite, tab_cursor, 0, 0,
+					  (void *) space, P4_SPACEPTR);
 			VdbeComment((v, "%s", space->index[0]->def->name));
 
 			if (one_pass == ONEPASS_MULTI)
diff --git a/src/box/sql/insert.c b/src/box/sql/insert.c
index 62b85d5..6aede16 100644
--- a/src/box/sql/insert.c
+++ b/src/box/sql/insert.c
@@ -204,13 +204,8 @@ vdbe_has_table_read(struct Parse *parser, const struct Table *table)
 		 * and Write cursors.
 		 */
 		if (op->opcode == OP_OpenRead || op->opcode == OP_OpenWrite) {
-			assert(i > 1);
-			struct VdbeOp *space_var_op =
-				sqlite3VdbeGetOp(v, i - 1);
-			assert(space_var_op != NULL);
-			assert(space_var_op->opcode == OP_LoadPtr);
-			struct space *space = space_var_op->p4.space;
-
+			assert(op->p4type == P4_SPACEPTR);
+			struct space *space = op->p4.space;
 			if (space->def->id == table->def->id)
 				return true;
 
@@ -1581,10 +1576,6 @@ sqlite3OpenTableAndIndices(Parse * pParse,	/* Parsing context */
 		*piIdxCur = iBase;
 	struct space *space = space_by_id(SQLITE_PAGENO_TO_SPACEID(pTab->tnum));
 	assert(space != NULL);
-	int space_ptr_reg = ++pParse->nMem;
-	sqlite3VdbeAddOp4(v, OP_LoadPtr, 0, space_ptr_reg, 0, (void*)space,
-			  P4_SPACEPTR);
-
 	/* One iteration of this cycle adds OpenRead/OpenWrite which
 	 * opens cursor for current index.
 	 *
@@ -1633,9 +1624,8 @@ sqlite3OpenTableAndIndices(Parse * pParse,	/* Parsing context */
 			if (aToOpen == 0 || aToOpen[i + 1]) {
 				int idx_id =
 					SQLITE_PAGENO_TO_INDEXID(pIdx->tnum);
-				sqlite3VdbeAddOp3(v, op, iIdxCur, idx_id,
-						  space_ptr_reg);
-				sql_vdbe_set_p4_key_def(pParse, pIdx);
+				sqlite3VdbeAddOp4(v, op, iIdxCur, idx_id, 0,
+						  (void *) space, P4_SPACEPTR);
 				sqlite3VdbeChangeP5(v, p5);
 				VdbeComment((v, "%s", pIdx->zName));
 			}
diff --git a/src/box/sql/pragma.c b/src/box/sql/pragma.c
index ca119e0..8ff5bbc 100644
--- a/src/box/sql/pragma.c
+++ b/src/box/sql/pragma.c
@@ -678,29 +678,28 @@ sqlite3Pragma(Parse * pParse, Token * pId,	/* First part of [schema.]id field */
 					x = sqlite3FkLocateIndex(pParse,
 								 pParent, pFK,
 								 &pIdx, 0);
-					if (x == 0) {
-						if (pIdx == 0) {
-							sqlite3OpenTable(pParse,
-									 i,
-									 pParent,
-									 OP_OpenRead);
-						} else {
-							int idx_id =
-								SQLITE_PAGENO_TO_INDEXID(
-									pIdx->
-									tnum);
-							sqlite3VdbeAddOp3(v,
-									  OP_OpenRead,
-									  i,
-									  idx_id,
-									  0);
-							sql_vdbe_set_p4_key_def(pParse,
-										pIdx);
-						}
-					} else {
+					if (x != 0) {
 						k = 0;
 						break;
 					}
+					if (pIdx == NULL) {
+						sqlite3OpenTable(pParse, i,
+								 pParent,
+								 OP_OpenRead);
+						continue;
+					}
+					struct space *space =
+						space_cache_find(pIdx->pTable->
+								 def->id);
+					int idx_id =
+						SQLITE_PAGENO_TO_INDEXID(pIdx->
+									 tnum);
+					assert(space != NULL);
+					sqlite3VdbeAddOp4(v, OP_OpenRead, i,
+							  idx_id, 0,
+							  (void *) space,
+							  P4_SPACEPTR);
+
 				}
 				assert(pParse->nErr > 0 || pFK == 0);
 				if (pFK)
diff --git a/src/box/sql/sqliteInt.h b/src/box/sql/sqliteInt.h
index 4a1eef0..18bf949 100644
--- a/src/box/sql/sqliteInt.h
+++ b/src/box/sql/sqliteInt.h
@@ -3008,11 +3008,6 @@ struct Parse {
 #define OPFLAG_NOOP_IF_NULL  0x02	/* OP_FCopy: if source register is NULL
 					 * then do nothing
 					 */
-#define OPFLAG_FRESH_PTR     0x20	/* OP_Open**: set if space pointer
-					 * comes from OP_SIDtoPtr, i.e. it
-					 * is fresh, even in case schema
-					 * changes previously.
-					 */
 
 /*
  * Each trigger present in the database schema is stored as an
diff --git a/src/box/sql/vdbe.c b/src/box/sql/vdbe.c
index a0eb41b..49a17b9 100644
--- a/src/box/sql/vdbe.c
+++ b/src/box/sql/vdbe.c
@@ -1077,19 +1077,6 @@ case OP_Int64: {           /* out2 */
 	break;
 }
 
-/* Opcode: LoadPtr * P2 * P4 *
- * Synopsis: r[P2] = P4
- *
- * P4 is a generic or space pointer. Copy it into register P2.
- */
-case OP_LoadPtr: {
-	pOut = out2Prerelease(p, pOp);
-	assert(pOp->p4type == P4_PTR || pOp->p4type == P4_SPACEPTR );
-	pOut->u.p = pOp->p4.space;
-	pOut->flags = MEM_Ptr;
-	break;
-}
-
 #ifndef SQLITE_OMIT_FLOATING_POINT
 /* Opcode: Real * P2 * P4 *
  * Synopsis: r[P2]=P4
@@ -3137,26 +3124,15 @@ case OP_SetCookie: {
 }
 
 /* Opcode: OpenRead P1 P2 P3 P4 P5
- * Synopsis: index id = P2, space ptr = P3
+ * Synopsis: index id = P2, space ptr = P4
  *
- * Open a cursor for a space specified by pointer in P3 and index
+ * Open a cursor for a space specified by pointer in P4 and index
  * id in P2. Give the new cursor an identifier of P1. The P1
  * values need not be contiguous but all P1 values should be
  * small integers. It is an error for P1 to be negative.
- *
- * The P4 value may be a pointer to a key_def structure.
- * If it is a pointer to a key_def structure, then said structure
- * defines the content and collatining sequence of the index
- * being opened. Otherwise, P4 is NULL.
- *
- * If schema has changed since compile time, VDBE ends execution
- * with appropriate error message. The only exception is
- * when P5 is set to OPFLAG_FRESH_PTR, which means that
- * space pointer has been fetched in runtime right before
- * this opcode.
  */
 /* Opcode: ReopenIdx P1 P2 P3 P4 P5
- * Synopsis: index id = P2, space ptr = P3
+ * Synopsis: index id = P2, space ptr = P4
  *
  * The ReopenIdx opcode works exactly like OpenRead except that
  * it first checks to see if the cursor on P1 is already open
@@ -3166,7 +3142,7 @@ case OP_SetCookie: {
  * The ReopenIdx opcode may only be used with P5 == 0.
  */
 /* Opcode: OpenWrite P1 P2 P3 P4 P5
- * Synopsis: index id = P2, space ptr = P3
+ * Synopsis: index id = P2, space ptr = P4
  *
  * For now, OpenWrite is an alias for OpenRead.
  * It exists just due legacy reasons and should be removed:
@@ -3182,9 +3158,7 @@ case OP_ReopenIdx: {
 	assert(pOp->p5==0 || pOp->p5==OPFLAG_SEEKEQ);
 	pCur = p->apCsr[pOp->p1];
 	p2 = pOp->p2;
-	pIn3 = &aMem[pOp->p3];
-	assert(pIn3->flags & MEM_Ptr);
-	if (pCur && pCur->uc.pCursor->space == (struct space *) pIn3->u.p &&
+	if (pCur && pCur->uc.pCursor->space == pOp->p4.space &&
 	    pCur->uc.pCursor->index->def->iid == (uint32_t)p2)
 		goto open_cursor_set_hints;
 	/* If the cursor is not currently open or is open on a different
@@ -3194,13 +3168,7 @@ case OP_OpenRead:
 case OP_OpenWrite:
 
 	assert(pOp->opcode==OP_OpenWrite || pOp->p5==0 || pOp->p5==OPFLAG_SEEKEQ);
-	/*
-	 * Even if schema has changed, pointer can come from
-	 * OP_SIDtoPtr opcode, which converts space id to pointer
-	 * during runtime.
-	 */
-	if (box_schema_version() != p->schema_ver &&
-	    (pOp->p5 & OPFLAG_FRESH_PTR) == 0) {
+	if (box_schema_version() != p->schema_ver) {
 		p->expired = 1;
 		rc = SQLITE_ERROR;
 		sqlite3VdbeError(p, "schema version has changed: " \
@@ -3208,9 +3176,7 @@ case OP_OpenWrite:
 		goto abort_due_to_error;
 	}
 	p2 = pOp->p2;
-	pIn3 = &aMem[pOp->p3];
-	assert(pIn3->flags & MEM_Ptr);
-	struct space *space = ((struct space *) pIn3->u.p);
+	struct space *space = pOp->p4.space;
 	assert(space != NULL);
 	struct index *index = space_index(space, p2);
 	assert(index != NULL);
@@ -4461,26 +4427,6 @@ case OP_SDelete: {
 	break;
 }
 
-/* Opcode: SIDtoPtr P1 P2 * * *
- * Synopsis: space id = P1, space[out] = r[P2]
- *
- * This opcode makes look up by space id and save found space
- * into register, specified by the content of register P2.
- * Such trick is needed during DLL routine, since schema may
- * change and pointers become expired.
- */
-case OP_SIDtoPtr: {
-	assert(pOp->p1 > 0);
-	assert(pOp->p2 >= 0);
-
-	pIn2 = out2Prerelease(p, pOp);
-	struct space *space = space_by_id(pOp->p1);
-	assert(space != NULL);
-	pIn2->u.p = (void *) space;
-	pIn2->flags = MEM_Ptr;
-	break;
-}
-
 /* Opcode: IdxDelete P1 P2 P3 * *
  * Synopsis: key=r[P2@P3]
  *
-- 
2.7.4