mdbx: backpost - ITS#8300 fix rebalance after node_move.

ITS#8258, ITS#7829 fixes checked parent index to see if we were moving
from a left neighbor. Should have just checked to see if current index
was 0, meaning we added on the left. (Parent index may not tell us
anything meaningful after a nested rebalance.)

Includes:

 - ITS#8300 fix node_move
   Don't adjust other cursors when we added a node on the right.

 - ITS#8300 more for node_move fixups
   When moving a node from the right neighbor, a different
   adjustment is needed.

 - ITS#8300 simplify

 - ITS#8300 more for node_move
   When moving a node from one page to another, make sure other cursors'
   parent index gets adjusted too.
This commit is contained in:
Howard Chu 2015-11-04 20:38:30 +00:00 committed by Leo Yuriev
parent 7890eb8a8e
commit ee26517b5d
2 changed files with 43 additions and 25 deletions

View File

@ -9,6 +9,7 @@ LMDB 0.9.17 Release Engineering
Fix ITS#8263 cursor_put cursor tracking
Fix ITS#8264 cursor_del cursor tracking
Fix ITS#8299 mdb_del cursor tracking
Fix ITS#8300 mdb_del cursor tracking
Fix ITS#7771 fakepage cursor tracking
Fix ITS#7789 ensure mapsize >= pages in use
Fix ITS#7971 mdb_txn_renew0() new reader slots

67
mdb.c
View File

@ -7738,32 +7738,48 @@ mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
/* Adjust other cursors pointing to mp */
MDB_cursor *m2, *m3;
MDB_dbi dbi = csrc->mc_dbi;
MDB_page *mp;
MDB_page *mpd, *mps;
mp = cdst->mc_pg[csrc->mc_top];
for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
if (csrc->mc_flags & C_SUB)
m3 = &m2->mc_xcursor->mx_cursor;
else
m3 = m2;
if (m3 == cdst) continue;
if (m3->mc_pg[csrc->mc_top] == mp && m3->mc_ki[csrc->mc_top] >=
cdst->mc_ki[csrc->mc_top]) {
m3->mc_ki[csrc->mc_top]++;
mps = csrc->mc_pg[csrc->mc_top];
/* If we're adding on the left, bump others up */
if (!cdst->mc_ki[csrc->mc_top]) {
mpd = cdst->mc_pg[csrc->mc_top];
for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
if (csrc->mc_flags & C_SUB)
m3 = &m2->mc_xcursor->mx_cursor;
else
m3 = m2;
if (m3 != cdst &&
m3->mc_pg[csrc->mc_top] == mpd &&
m3->mc_ki[csrc->mc_top] >= cdst->mc_ki[csrc->mc_top]) {
m3->mc_ki[csrc->mc_top]++;
}
if (m3 !=csrc &&
m3->mc_pg[csrc->mc_top] == mps &&
m3->mc_ki[csrc->mc_top] == csrc->mc_ki[csrc->mc_top]) {
m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
m3->mc_ki[csrc->mc_top-1]++;
}
}
}
mp = csrc->mc_pg[csrc->mc_top];
for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
if (csrc->mc_flags & C_SUB)
m3 = &m2->mc_xcursor->mx_cursor;
else
m3 = m2;
if (m3 == csrc) continue;
if (m3->mc_pg[csrc->mc_top] == mp && m3->mc_ki[csrc->mc_top] ==
csrc->mc_ki[csrc->mc_top]) {
m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
} else
/* Adding on the right, bump others down */
{
for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
if (csrc->mc_flags & C_SUB)
m3 = &m2->mc_xcursor->mx_cursor;
else
m3 = m2;
if (m3 == csrc) continue;
if (m3->mc_pg[csrc->mc_top] == mps) {
if (!m3->mc_ki[csrc->mc_top]) {
m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
m3->mc_ki[csrc->mc_top-1]--;
} else {
m3->mc_ki[csrc->mc_top]--;
}
}
}
}
}
@ -8151,7 +8167,8 @@ mdb_rebalance(MDB_cursor *mc)
*/
if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= thresh && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) {
rc = mdb_node_move(&mn, mc);
if (mc->mc_ki[mc->mc_top-1]) {
if (!mc->mc_ki[mc->mc_top]) {
/* if we inserted on left, bump position up */
oldki++;
}
} else {