Commit 56c2a8d0 authored by Howard Chu's avatar Howard Chu
Browse files

Another take on spill_pgs and deletes

parent b917266c
......@@ -847,7 +847,8 @@ struct MDB_txn {
*/
MDB_IDL mt_free_pgs;
/** The sorted list of dirty pages we temporarily wrote to disk
* because the dirty list was full.
* because the dirty list was full. page numbers in here are
* shifted left by 1, deleted slots have the LSB set.
*/
MDB_IDL mt_spill_pgs;
union {
......@@ -1476,12 +1477,12 @@ mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)
if (!txn->mt_spill_pgs)
return ENOMEM;
} else {
/* strip any dups */
/* purge deleted slots */
MDB_IDL sl = txn->mt_spill_pgs;
unsigned int num = sl[0];
j=1;
j=0;
for (i=1; i<=num; i++) {
if (sl[j] != sl[i])
if (!(sl[i] & 1))
sl[++j] = sl[i];
}
sl[0] = j;
......@@ -1504,6 +1505,7 @@ mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)
/* Save the page IDs of all the pages we're flushing */
/* flush from the tail forward, this saves a lot of shifting later on. */
for (i=dl[0].mid; i && need; i--) {
MDB_ID pn = dl[i].mid << 1;
dp = dl[i].mptr;
if (dp->mp_flags & P_KEEP)
continue;
......@@ -1514,8 +1516,8 @@ mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)
MDB_txn *tx2;
for (tx2 = txn->mt_parent; tx2; tx2 = tx2->mt_parent) {
if (tx2->mt_spill_pgs) {
j = mdb_midl_search(tx2->mt_spill_pgs, dl[i].mid);
if (j <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[j] == dl[i].mid) {
j = mdb_midl_search(tx2->mt_spill_pgs, pn);
if (j <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[j] == pn) {
dp->mp_flags |= P_KEEP;
break;
}
......@@ -1524,7 +1526,7 @@ mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)
if (tx2)
continue;
}
if ((rc = mdb_midl_append(&txn->mt_spill_pgs, dl[i].mid)))
if ((rc = mdb_midl_append(&txn->mt_spill_pgs, pn)))
goto done;
need--;
}
......@@ -1798,13 +1800,13 @@ mdb_page_unspill(MDB_txn *tx0, MDB_page *mp, MDB_page **ret)
MDB_env *env = tx0->mt_env;
MDB_txn *txn;
unsigned x;
pgno_t pgno = mp->mp_pgno;
pgno_t pgno = mp->mp_pgno, pn = pgno << 1;
for (txn = tx0; txn; txn=txn->mt_parent) {
if (!txn->mt_spill_pgs)
continue;
x = mdb_midl_search(txn->mt_spill_pgs, pgno);
if (x <= txn->mt_spill_pgs[0] && txn->mt_spill_pgs[x] == pgno) {
x = mdb_midl_search(txn->mt_spill_pgs, pn);
if (x <= txn->mt_spill_pgs[0] && txn->mt_spill_pgs[x] == pn) {
MDB_page *np;
int num;
if (IS_OVERFLOW(mp))
......@@ -1825,13 +1827,12 @@ mdb_page_unspill(MDB_txn *tx0, MDB_page *mp, MDB_page **ret)
if (txn == tx0) {
/* If in current txn, this page is no longer spilled.
* If it happens to be the last page, truncate the spill list.
* Otherwise temporarily dup its neighbor over it. Dups will
* be stripped out later by the next mdb_page_spill run.
* Otherwise mark it as deleted by setting the LSB.
*/
if (x == txn->mt_spill_pgs[0])
txn->mt_spill_pgs[0]--;
else
txn->mt_spill_pgs[x] = txn->mt_spill_pgs[x+1];
txn->mt_spill_pgs[x] |= 1;
} /* otherwise, if belonging to a parent txn, the
* page remains spilled until child commits
*/
......@@ -2823,9 +2824,10 @@ mdb_txn_commit(MDB_txn *txn)
len = x;
/* zero out our dirty pages in parent spill list */
for (i=1; i<=src[0].mid; i++) {
if (src[i].mid < parent->mt_spill_pgs[x])
MDB_ID pn = src[i].mid << 1;
if (pn < parent->mt_spill_pgs[x])
continue;
if (src[i].mid > parent->mt_spill_pgs[x]) {
if (pn > parent->mt_spill_pgs[x]) {
if (x <= 1)
break;
x--;
......@@ -4533,8 +4535,9 @@ mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret, int *lvl)
* leave that unless page_touch happens again).
*/
if (tx2->mt_spill_pgs) {
x = mdb_midl_search(tx2->mt_spill_pgs, pgno);
if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pgno) {
MDB_ID pn = pgno << 1;
x = mdb_midl_search(tx2->mt_spill_pgs, pn);
if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
p = (MDB_page *)(env->me_map + env->me_psize * pgno);
goto done;
}
......@@ -4764,6 +4767,7 @@ mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)
unsigned x = 0, ovpages = mp->mp_pages;
MDB_env *env = txn->mt_env;
MDB_IDL sl = txn->mt_spill_pgs;
MDB_ID pn = pg << 1;
int rc;
DPRINTF(("free ov page %"Z"u (%d)", pg, ovpages));
......@@ -4778,7 +4782,7 @@ mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)
if (env->me_pghead &&
!txn->mt_parent &&
((mp->mp_flags & P_DIRTY) ||
(sl && (x = mdb_midl_search(sl, pg)) <= sl[0] && sl[x] == pg)))
(sl && (x = mdb_midl_search(sl, pn)) <= sl[0] && sl[x] == pn)))
{
unsigned i, j;
pgno_t *mop;
......@@ -4788,9 +4792,10 @@ mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)
return rc;
if (!(mp->mp_flags & P_DIRTY)) {
/* This page is no longer spilled */
for (; x < sl[0]; x++)
sl[x] = sl[x+1];
sl[0]--;
if (x == sl[0])
sl[0]--;
else
sl[x] |= 1;
goto release;
}
/* Remove from dirty list */
......
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment