database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-08-07 02:42:48 +03:00
Code Activity

Fix comments and strengthen assert() statements associated with the

Browse Source 
OPFLAG_SEEKEQ and BTREE_SEEK_EQ flags.

FossilOrigin-Name: 231749213854756b599b33413b17b35186f17889b0c73f109fa9db726b415558
This commit is contained in:
drh
2020-03-12 17:28:27 +00:00
parent 2267a7fa87
commit 576d0a9fd9
4 changed files with 34 additions and 30 deletions
Download Patch File Download Diff File Expand all files Collapse all files

43
src/vdbe.c
View File

@@ -3664,7 +3664,7 @@ case OP_SetCookie: {
** <ul>
** <li> <b>0x02 OPFLAG_SEEKEQ</b>: This cursor will only be used for
** equality lookups (implemented as a pair of opcodes OP_SeekGE/OP_IdxGT
** of OP_SeekLE/OP_IdxGT)
** of OP_SeekLE/OP_IdxLT)
** </ul>
**
** The P4 value may be either an integer (P4_INT32) or a pointer to
@@ -3694,7 +3694,7 @@ case OP_SetCookie: {
** <ul>
** <li> <b>0x02 OPFLAG_SEEKEQ</b>: This cursor will only be used for
** equality lookups (implemented as a pair of opcodes OP_SeekGE/OP_IdxGT
** of OP_SeekLE/OP_IdxGT)
** of OP_SeekLE/OP_IdxLT)
** </ul>
**
** See also: OP_OpenRead, OP_OpenWrite
@@ -3718,7 +3718,7 @@ case OP_SetCookie: {
** <ul>
** <li> <b>0x02 OPFLAG_SEEKEQ</b>: This cursor will only be used for
** equality lookups (implemented as a pair of opcodes OP_SeekGE/OP_IdxGT
** of OP_SeekLE/OP_IdxGT)
** of OP_SeekLE/OP_IdxLT)
** <li> <b>0x08 OPFLAG_FORDELETE</b>: This cursor is used only to seek
** and subsequently delete entries in an index btree. This is a
** hint to the storage engine that the storage engine is allowed to
@@ -3830,9 +3830,7 @@ open_cursor_set_hints:
assert( OPFLAG_BULKCSR==BTREE_BULKLOAD );
assert( OPFLAG_SEEKEQ==BTREE_SEEK_EQ );
testcase( pOp->p5 & OPFLAG_BULKCSR );
#ifdef SQLITE_ENABLE_CURSOR_HINTS
testcase( pOp->p2 & OPFLAG_SEEKEQ );
#endif
sqlite3BtreeCursorHintFlags(pCur->uc.pCursor,
(pOp->p5 & (OPFLAG_BULKCSR|OPFLAG_SEEKEQ)));
if( rc ) goto abort_due_to_error;
@@ -4088,11 +4086,13 @@ case OP_ColumnsUsed: {
** greater than or equal to the key and P2 is not zero, then jump to P2.
**
** If the cursor P1 was opened using the OPFLAG_SEEKEQ flag, then this
** opcode will always land on a record that equally equals the key, or
** else jump immediately to P2. When the cursor is OPFLAG_SEEKEQ, this
** opcode must be followed by an IdxLE opcode with the same arguments.
** The IdxLE opcode will be skipped if this opcode succeeds, but the
** IdxLE opcode will be used on subsequent loop iterations.
** opcode will either land on a record that exactly matches the key, or
** else it will cause a jump to P2. When the cursor is OPFLAG_SEEKEQ,
** this opcode must be followed by an IdxLE opcode with the same arguments.
** The IdxGT opcode will be skipped if this opcode succeeds, but the
** IdxGT opcode will be used on subsequent loop iterations. The
** OPFLAG_SEEKEQ flags is a hint to the btree layer to say that this
** is an equality search.
**
** This opcode leaves the cursor configured to move in forward order,
** from the beginning toward the end. In other words, the cursor is
@@ -4108,7 +4108,7 @@ case OP_ColumnsUsed: {
** to an SQL index, then P3 is the first in an array of P4 registers
** that are used as an unpacked index key.
**
** Reposition cursor P1 so that it points to the smallest entry that
** Reposition cursor P1 so that it points to the smallest entry that
** is greater than the key value. If there are no records greater than
** the key and P2 is not zero, then jump to P2.
**
@@ -4153,11 +4153,13 @@ case OP_ColumnsUsed: {
** configured to use Prev, not Next.
**
** If the cursor P1 was opened using the OPFLAG_SEEKEQ flag, then this
** opcode will always land on a record that equally equals the key, or
** else jump immediately to P2. When the cursor is OPFLAG_SEEKEQ, this
** opcode must be followed by an IdxGE opcode with the same arguments.
** opcode will either land on a record that exactly matches the key, or
** else it will cause a jump to P2. When the cursor is OPFLAG_SEEKEQ,
** this opcode must be followed by an IdxLE opcode with the same arguments.
** The IdxGE opcode will be skipped if this opcode succeeds, but the
** IdxGE opcode will be used on subsequent loop iterations.
** IdxGE opcode will be used on subsequent loop iterations. The
** OPFLAG_SEEKEQ flags is a hint to the btree layer to say that this
** is an equality search.
**
** See also: Found, NotFound, SeekGt, SeekGe, SeekLt
*/
@@ -4194,7 +4196,7 @@ case OP_SeekGT: { /* jump, in3, group */
pC->cacheStatus = CACHE_STALE;
if( pC->isTable ){
u16 flags3, newType;
/* The BTREE_SEEK_EQ flag is only set on index cursors */
/* The OPFLAG_SEEKEQ/BTREE_SEEK_EQ flag is only set on index cursors */
assert( sqlite3BtreeCursorHasHint(pC->uc.pCursor, BTREE_SEEK_EQ)==0
|| CORRUPT_DB );
@@ -4253,14 +4255,17 @@ case OP_SeekGT: { /* jump, in3, group */
goto abort_due_to_error;
}
}else{
/* For a cursor with the BTREE_SEEK_EQ hint, only the OP_SeekGE and
** OP_SeekLE opcodes are allowed, and these must be immediately followed
** by an OP_IdxGT or OP_IdxLT opcode, respectively, with the same key.
/* For a cursor with the OPFLAG_SEEKEQ/BTREE_SEEK_EQ hint, only the
** OP_SeekGE and OP_SeekLE opcodes are allowed, and these must be
** immediately followed by an OP_IdxGT or OP_IdxLT opcode, respectively,
** with the same key.
*/
if( sqlite3BtreeCursorHasHint(pC->uc.pCursor, BTREE_SEEK_EQ) ){
eqOnly = 1;
assert( pOp->opcode==OP_SeekGE || pOp->opcode==OP_SeekLE );
assert( pOp[1].opcode==OP_IdxLT || pOp[1].opcode==OP_IdxGT );
assert( pOp->opcode==OP_SeekGE || pOp[1].opcode==OP_IdxLT );
assert( pOp->opcode==OP_SeekLE || pOp[1].opcode==OP_IdxGT );
assert( pOp[1].p1==pOp[0].p1 );
assert( pOp[1].p2==pOp[0].p2 );
assert( pOp[1].p3==pOp[0].p3 );