Simplify last commits

diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 708964b..640419c 100644 (file)
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -1354,19 +1354,24 @@ mdb_dlist_free(MDB_txn *txn)
        dl[0].mid = 0;
 }
 
-/* Set or clear P_KEEP in non-overflow, non-sub pages in this txn's cursors.
+/* Set or clear P_KEEP in dirty, non-overflow, non-sub pages watched by txn.
  * @param[in] mc A cursor handle for the current operation.
  * @param[in] pflags Flags of the pages to update:
  * P_DIRTY to set P_KEEP, P_DIRTY|P_KEEP to clear it.
+ * @param[in] all No shortcuts. Needed except after a full #mdb_page_flush().
+ * @return 0 on success, non-zero on failure.
  */
-static void
-mdb_cursorpages_mark(MDB_cursor *mc, unsigned pflags)
+static int
+mdb_pages_xkeep(MDB_cursor *mc, unsigned pflags, int all)
 {
        MDB_txn *txn = mc->mc_txn;
        MDB_cursor *m3;
        MDB_xcursor *mx;
+       MDB_page *dp;
        unsigned i, j;
+       int rc = MDB_SUCCESS, level;
 
+       /* Mark pages seen by cursors */
        if (mc->mc_flags & C_UNTRACK)
                mc = NULL;                              /* will find mc in mt_cursors */
        for (i = txn->mt_numdbs;; mc = txn->mt_cursors[--i]) {
@@ -1384,9 +1389,26 @@ mdb_cursorpages_mark(MDB_cursor *mc, unsigned pflags)
                if (i == 0)
                        break;
        }
+
+       if (all) {
+               /* Mark dirty root pages */
+               for (i=0; i<txn->mt_numdbs; i++) {
+                       if (txn->mt_dbflags[i] & DB_DIRTY) {
+                               pgno_t pgno = txn->mt_dbs[i].md_root;
+                               if (pgno == P_INVALID)
+                                       continue;
+                               if ((rc = mdb_page_get(txn, pgno, &dp, &level)) != MDB_SUCCESS)
+                                       break;
+                               if ((dp->mp_flags & (P_DIRTY|P_KEEP)) == pflags && level <= 1)
+                                       dp->mp_flags ^= P_KEEP;
+                       }
+               }
+       }
+
+       return rc;
 }
 
-static int mdb_page_flush(MDB_txn *txn);
+static int mdb_page_flush(MDB_txn *txn, int keep);
 
 /**    Spill pages from the dirty list back to disk.
  * This is intended to prevent running into #MDB_TXN_FULL situations,
@@ -1429,8 +1451,8 @@ mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)
        MDB_txn *txn = m0->mc_txn;
        MDB_page *dp;
        MDB_ID2L dl = txn->mt_u.dirty_list;
-       unsigned int i, j, k, need;
-       int rc, level;
+       unsigned int i, j, need;
+       int rc;
 
        if (m0->mc_flags & C_SUB)
                return MDB_SUCCESS;
@@ -1455,21 +1477,9 @@ mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)
                        return ENOMEM;
        }
 
-       /* Mark all the dirty root pages we want to preserve */
-       for (i=0; i<txn->mt_numdbs; i++) {
-               if (txn->mt_dbflags[i] & DB_DIRTY) {
-                       pgno_t pgno = txn->mt_dbs[i].md_root;
-                       if (pgno == P_INVALID)
-                               continue;
-                       if ((rc = mdb_page_get(txn, pgno, &dp, &level)) != MDB_SUCCESS)
-                               goto done;
-                       if ((dp->mp_flags & P_DIRTY) && level <= 1)
-                               dp->mp_flags |= P_KEEP;
-               }
-       }
-
-       /* Preserve pages used by cursors */
-       mdb_cursorpages_mark(m0, P_DIRTY);
+       /* Preserve pages which may soon be dirtied again */
+       if ((rc = mdb_pages_xkeep(m0, P_DIRTY, 1)) != MDB_SUCCESS)
+               goto done;
 
        /* Less aggressive spill - we originally spilled the entire dirty list,
         * with a few exceptions for cursor pages and DB root pages. But this
@@ -1478,13 +1488,12 @@ mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)
         * of the dirty pages. Testing revealed this to be a good tradeoff,
         * better than 1/2, 1/4, or 1/10.
         */
-       k = 0;
        if (need < MDB_IDL_UM_MAX / 8)
                need = MDB_IDL_UM_MAX / 8;
 
        /* 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>0; i--) {
+       for (i=dl[0].mid; i && need; i--) {
                dp = dl[i].mptr;
                if (dp->mp_flags & P_KEEP)
                        continue;
@@ -1507,51 +1516,16 @@ mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)
                }
                if ((rc = mdb_midl_append(&txn->mt_spill_pgs, dl[i].mid)))
                        goto done;
-               k++;
-               if (k > need)
-                       break;
+               need--;
        }
        mdb_midl_sort(txn->mt_spill_pgs);
 
-       /* Since we're only doing the tail 1/8th of the dirty list,
-        * fake a dirty list to reflect this.
-        */
-       {
-               MDB_ID2 old;
-               if (i) {
-                       k = dl[0].mid - i + 1;
-                       old = dl[i-1];
-                       dl[i-1].mid = k;
-                       txn->mt_u.dirty_list = &dl[i-1];
-               }
-
-               rc = mdb_page_flush(txn);
-
-               if (i) {
-                       /* reset back to the real list */
-                       dl[0].mid -= k;
-                       dl[0].mid += dl[i-1].mid;
-                       dl[i-1] = old;
-                       txn->mt_u.dirty_list = dl;
-               }
-       }
-
-       mdb_cursorpages_mark(m0, P_DIRTY|P_KEEP);
+       /* Flush the spilled part of dirty list */
+       if ((rc = mdb_page_flush(txn, i)) != MDB_SUCCESS)
+               goto done;
 
-       if (i) {
-               /* Reset any dirty root pages we kept that page_flush didn't see */
-               for (i=0; i<txn->mt_numdbs; i++) {
-                       if (txn->mt_dbflags[i] & DB_DIRTY) {
-                               pgno_t pgno = txn->mt_dbs[i].md_root;
-                               if (pgno == P_INVALID)
-                                       continue;
-                               if ((rc = mdb_page_get(txn, pgno, &dp, &level)) != MDB_SUCCESS)
-                                       goto done;
-                               if (dp->mp_flags & P_KEEP)
-                                       dp->mp_flags ^= P_KEEP;
-                       }
-               }
-       }
+       /* Reset any dirty pages we kept that page_flush didn't see */
+       rc = mdb_pages_xkeep(m0, P_DIRTY|P_KEEP, i);
 
 done:
        if (rc == 0) {
@@ -2626,10 +2600,13 @@ mdb_freelist_save(MDB_txn *txn)
        return rc;
 }
 
-/** Flush dirty pages to the map, after clearing their dirty flag.
+/** Flush (some) dirty pages to the map, after clearing their dirty flag.
+ * @param[in] txn the transaction that's being committed
+ * @param[in] keep number of initial pages in dirty_list to keep dirty.
+ * @return 0 on success, non-zero on failure.
  */
 static int
-mdb_page_flush(MDB_txn *txn)
+mdb_page_flush(MDB_txn *txn, int keep)
 {
        MDB_env         *env = txn->mt_env;
        MDB_ID2L        dl = txn->mt_u.dirty_list;
@@ -2647,10 +2624,11 @@ mdb_page_flush(MDB_txn *txn)
        int                     n = 0;
 #endif
 
-       j = 0;
+       j = i = keep;
+
        if (env->me_flags & MDB_WRITEMAP) {
                /* Clear dirty flags */
-               for (i=1; i<=pagecount; i++) {
+               while (++i <= pagecount) {
                        dp = dl[i].mptr;
                        /* Don't flush this page yet */
                        if (dp->mp_flags & P_KEEP) {
@@ -2665,8 +2643,8 @@ mdb_page_flush(MDB_txn *txn)
        }
 
        /* Write the pages */
-       for (i = 1;; i++) {
-               if (i <= pagecount) {
+       for (;;) {
+               if (++i <= pagecount) {
                        dp = dl[i].mptr;
                        /* Don't flush this page yet */
                        if (dp->mp_flags & P_KEEP) {
@@ -2745,8 +2723,7 @@ mdb_page_flush(MDB_txn *txn)
 #endif /* _WIN32 */
        }
 
-       j = 0;
-       for (i=1; i<=pagecount; i++) {
+       for (i = keep; ++i <= pagecount; ) {
                dp = dl[i].mptr;
                /* This is a page we skipped above */
                if (!dl[i].mid) {
@@ -2949,7 +2926,7 @@ mdb_txn_commit(MDB_txn *txn)
        mdb_audit(txn);
 #endif
 
-       if ((rc = mdb_page_flush(txn)) ||
+       if ((rc = mdb_page_flush(txn, 0)) ||
                (rc = mdb_env_sync(env, 0)) ||
                (rc = mdb_env_write_meta(txn)))
                goto fail;