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ITS#8258 fix rebalance/split

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The tree height can also increase during rebalance, not just shrink.
This can happen if update_key needs to split a parent branch page.
mdb.RE/0.9
Howard Chu 9 years ago
parent eccea851ff
commit 8bdadf68c5
1 changed files with 6 additions and 7 deletions
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  1. 13
      libraries/liblmdb/mdb.c

13
libraries/liblmdb/mdb.c
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@ -7643,9 +7643,9 @@ mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
uint16_t depth = cdst->mc_db->md_depth; uint16_t depth = cdst->mc_db->md_depth;
mdb_cursor_pop(cdst); mdb_cursor_pop(cdst);
rc = mdb_rebalance(cdst); rc = mdb_rebalance(cdst);
/* Did the tree shrink? */ /* Did the tree height change? */
if (depth > cdst->mc_db->md_depth) if (depth != cdst->mc_db->md_depth)
snum--; snum += cdst->mc_db->md_depth - depth;
cdst->mc_snum = snum; cdst->mc_snum = snum;
cdst->mc_top = snum-1; cdst->mc_top = snum-1;
} }
@ -7837,7 +7837,7 @@ 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) { 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); rc = mdb_node_move(&mn, mc);
if (mc->mc_ki[ptop]) { if (mc->mc_ki[mc->mc_top-1]) {
oldki++; oldki++;
} }
} else { } else {
@ -8050,8 +8050,7 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
mc->mc_ki[0] = 0; mc->mc_ki[0] = 0;
mc->mc_db->md_root = pp->mp_pgno; mc->mc_db->md_root = pp->mp_pgno;
DPRINTF(("root split! new root = %"Z"u", pp->mp_pgno)); DPRINTF(("root split! new root = %"Z"u", pp->mp_pgno));
mc->mc_db->md_depth++; new_root = mc->mc_db->md_depth++;
new_root = 1;
/* Add left (implicit) pointer. */ /* Add left (implicit) pointer. */
if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) { if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) {
@ -8364,7 +8363,7 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
if (new_root) { if (new_root) {
int k; int k;
/* root split */ /* root split */
for (k=m3->mc_top; k>=0; k--) { for (k=new_root; k>=0; k--) {
m3->mc_ki[k+1] = m3->mc_ki[k]; m3->mc_ki[k+1] = m3->mc_ki[k];
m3->mc_pg[k+1] = m3->mc_pg[k]; m3->mc_pg[k+1] = m3->mc_pg[k];
} }

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