Commit 3b55853f authored by Hallvard Furuseth's avatar Hallvard Furuseth Committed by Howard Chu
Browse files

Drop unnecessary searches in the spill lists

Check with IS_MUTABLE() if an MDB_page is spilled, instead of
searching spill lists.  When unspilling, skip parent spill lists.
parent 34461da9
......@@ -1037,6 +1037,9 @@ typedef struct MDB_page {
/** Test if a page is a sub page */
#define IS_SUBP(p) F_ISSET((p)->mp_flags, P_SUBP)
/** Test if this non-sub page belongs to the current snapshot */
#define IS_MUTABLE(txn, p) ((p)->mp_txnid == (txn)->mt_txnid)
/** Info about overflow page, stored in an F_BIGDATA node */
typedef struct MDB_ovpage {
pgno_t op_pgno;
......@@ -2730,31 +2733,34 @@ mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize)
}
}
/** Pull a page off the txn's spill list, if present.
* If a page being referenced was spilled to disk in this txn, bring
* it back and make it dirty/writable again.
/** Bring back a page which this txn spilled to disk; make it writable again.
* @param[in] txn the transaction handle.
* @param[in] mp the page being referenced. It must not be dirty.
* @param[out] ret the writable page, if any. ret is unchanged if
* mp wasn't spilled.
* @param[in] mp the spilled page.
* @param[out] ret the writable page.
*/
static int
mdb_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret)
{
MDB_env *env = txn->mt_env;
const MDB_txn *tx2;
unsigned x;
pgno_t pgno = mp->mp_pgno, pn = pgno << 1;
for (tx2 = txn; tx2; tx2=tx2->mt_parent) {
if (!tx2->mt_spill_pgs)
continue;
x = mdb_midl_search(tx2->mt_spill_pgs, pn);
if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
if (txn->mt_dirty_room == 0)
return MDB_TXN_FULL;
/* x = position in current spill list, or 0 */
x = 0;
if (txn->mt_spill_pgs) {
x = mdb_midl_search(txn->mt_spill_pgs, pn);
if (! (x <= txn->mt_spill_pgs[0] && txn->mt_spill_pgs[x] == pn))
x = 0;
}
if (x == 0 && !txn->mt_parent)
return MDB_PROBLEM; /* should be a spilled page */
{
MDB_page *np;
int num;
if (txn->mt_dirty_room == 0)
return MDB_TXN_FULL;
if (IS_OVERFLOW(mp))
num = mp->mp_pages;
else
......@@ -2770,7 +2776,7 @@ mdb_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret)
else
mdb_page_copy(np, mp, env->me_psize);
}
if (tx2 == txn) {
if (x) {
/* If in current txn, this page is no longer spilled.
* If it happens to be the last page, truncate the spill list.
* Otherwise mark it as deleted by setting the LSB.
......@@ -2786,10 +2792,8 @@ mdb_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret)
mdb_page_dirty(txn, np);
np->mp_flags |= P_DIRTY;
*ret = np;
break;
}
return MDB_SUCCESS;
}
return MDB_SUCCESS;
}
/** Touch a page: make it dirty and re-insert into tree with updated pgno.
......@@ -2807,13 +2811,11 @@ mdb_page_touch(MDB_cursor *mc)
int rc;
if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
if (txn->mt_flags & MDB_TXN_SPILLS) {
np = NULL;
if (IS_MUTABLE(txn, mp)) {
rc = mdb_page_unspill(txn, mp, &np);
if (rc)
goto fail;
if (np)
goto done;
goto done;
}
if ((rc = mdb_midl_need(&txn->mt_free_pgs, 1)) ||
(rc = mdb_page_alloc(mc, 1, &np)))
......@@ -6864,7 +6866,6 @@ mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)
pgno_t pg = mp->mp_pgno;
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;
......@@ -6877,11 +6878,7 @@ mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)
* Unsupported in nested txns: They would need to hide the page
* range in ancestor txns' dirty and spilled lists.
*/
if (env->me_pghead &&
!txn->mt_parent &&
((mp->mp_flags & P_DIRTY) ||
(sl && (x = mdb_midl_search(sl, pn)) <= sl[0] && sl[x] == pn)))
{
if (IS_MUTABLE(txn, mp) && env->me_pghead && !txn->mt_parent) {
unsigned i, j;
pgno_t *mop;
MDB_ID2 *dl, ix, iy;
......@@ -6889,6 +6886,11 @@ mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)
if (rc)
return rc;
if (!(mp->mp_flags & P_DIRTY)) {
MDB_IDL sl = txn->mt_spill_pgs;
if (sl)
x = mdb_midl_search(sl, pn);
if (! (sl && x <= sl[0] && sl[x] == pn))
return MDB_PROBLEM;
/* This page is no longer spilled */
if (x == sl[0])
sl[0]--;
......@@ -8073,23 +8075,18 @@ current:
return rc2;
ovpages = ovp.op_pages;
/* Is the ov page large enough? */
if (ovpages >= dpages) {
/* Did we dirty it in this txn? */
if (!(omp->mp_flags & P_DIRTY) &&
(level || (env->me_flags & MDB_WRITEMAP)))
{
rc = mdb_page_unspill(mc->mc_txn, omp, &omp);
if (rc)
return rc;
level = 0; /* dirty in this txn or clean */
}
/* Is it dirty? */
if (omp->mp_flags & P_DIRTY) {
/* Is the ov page big enough and from this txn (or a parent)? */
if (ovpages >= dpages && IS_MUTABLE(mc->mc_txn, omp)) {
/* yes, overwrite it. Note in this case we don't
* bother to try shrinking the page if the new data
* is smaller than the overflow threshold.
*/
if (!(omp->mp_flags & P_DIRTY)) {
rc = mdb_page_unspill(mc->mc_txn, omp, &omp);
if (rc)
return rc;
level = 0; /* dirty in this txn */
}
if (level > 1) {
/* It is writable only in a parent txn */
size_t sz = (size_t) env->me_psize * ovpages, off;
......@@ -8125,7 +8122,6 @@ current:
else
memcpy(METADATA(omp), data->mv_data, data->mv_size);
return MDB_SUCCESS;
}
}
if ((rc2 = mdb_ovpage_free(mc, omp)) != MDB_SUCCESS)
return rc2;
......
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