More cleanup for page_merge, page_loosen

Only loosen src page if it's actually dirty.
Refactor page refs in page_merge.

diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index c6985b009bbe8beffe201d8650854e0c6b18dc70..e5bfc84996eb1df127e0c149afd60cda9a5aeded 100644 (file)
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -7251,14 +7251,17 @@ mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
 static int
 mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
 {
-       int                      rc;
-       indx_t                   i, j;
-       MDB_node                *srcnode;
+       MDB_page        *psrc, *pdst;
+       MDB_node        *srcnode;
        MDB_val          key, data;
-       unsigned        nkeys;
+       unsigned         nkeys;
+       int                      rc;
+       indx_t           i, j;
 
-       DPRINTF(("merging page %"Z"u into %"Z"u", csrc->mc_pg[csrc->mc_top]->mp_pgno,
-               cdst->mc_pg[cdst->mc_top]->mp_pgno));
+       psrc = csrc->mc_pg[csrc->mc_top];
+       pdst = cdst->mc_pg[cdst->mc_top];
+
+       DPRINTF(("merging page %"Z"u into %"Z"u", psrc->mp_pgno, pdst->mp_pgno));
 
        mdb_cassert(csrc, csrc->mc_snum > 1);   /* can't merge root page */
        mdb_cassert(csrc, cdst->mc_snum > 1);
@@ -7269,20 +7272,20 @@ mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
 
        /* Move all nodes from src to dst.
         */
-       j = nkeys = NUMKEYS(cdst->mc_pg[cdst->mc_top]);
-       if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
+       j = nkeys = NUMKEYS(pdst);
+       if (IS_LEAF2(psrc)) {
                key.mv_size = csrc->mc_db->md_pad;
-               key.mv_data = METADATA(csrc->mc_pg[csrc->mc_top]);
-               for (i = 0; i < NUMKEYS(csrc->mc_pg[csrc->mc_top]); i++, j++) {
+               key.mv_data = METADATA(psrc);
+               for (i = 0; i < NUMKEYS(psrc); i++, j++) {
                        rc = mdb_node_add(cdst, j, &key, NULL, 0, 0);
                        if (rc != MDB_SUCCESS)
                                return rc;
                        key.mv_data = (char *)key.mv_data + key.mv_size;
                }
        } else {
-               for (i = 0; i < NUMKEYS(csrc->mc_pg[csrc->mc_top]); i++, j++) {
-                       srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], i);
-                       if (i == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
+               for (i = 0; i < NUMKEYS(psrc); i++, j++) {
+                       srcnode = NODEPTR(psrc, i);
+                       if (i == 0 && IS_BRANCH(psrc)) {
                                MDB_cursor mn;
                                MDB_node *s2;
                                mdb_cursor_copy(csrc, &mn);
@@ -7312,8 +7315,8 @@ mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
        }
 
        DPRINTF(("dst page %"Z"u now has %u keys (%.1f%% filled)",
-           cdst->mc_pg[cdst->mc_top]->mp_pgno, NUMKEYS(cdst->mc_pg[cdst->mc_top]),
-               (float)PAGEFILL(cdst->mc_txn->mt_env, cdst->mc_pg[cdst->mc_top]) / 10));
+           pdst->mp_pgno, NUMKEYS(pdst),
+               (float)PAGEFILL(cdst->mc_txn->mt_env, pdst) / 10));
 
        /* Unlink the src page from parent and add to free list.
         */
@@ -7329,8 +7332,15 @@ mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
        }
        csrc->mc_top++;
 
-       mdb_page_loose(csrc->mc_txn->mt_env, csrc->mc_pg[csrc->mc_top]);
-       if (IS_LEAF(csrc->mc_pg[csrc->mc_top]))
+       psrc = csrc->mc_pg[csrc->mc_top];
+       if (psrc->mp_flags & P_DIRTY) {
+               mdb_page_loose(csrc->mc_txn->mt_env, psrc);
+       } else {
+               rc = mdb_midl_append(&csrc->mc_txn->mt_free_pgs, psrc->mp_pgno);
+               if (rc)
+                       return rc;
+       }
+       if (IS_LEAF(psrc))
                csrc->mc_db->md_leaf_pages--;
        else
                csrc->mc_db->md_branch_pages--;
@@ -7338,7 +7348,6 @@ mdb_page_merge(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 = cdst->mc_pg[cdst->mc_top];
 
                for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
                        if (csrc->mc_flags & C_SUB)
@@ -7347,8 +7356,8 @@ mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
                                m3 = m2;
                        if (m3 == csrc) continue;
                        if (m3->mc_snum < csrc->mc_snum) continue;
-                       if (m3->mc_pg[csrc->mc_top] == csrc->mc_pg[csrc->mc_top]) {
-                               m3->mc_pg[csrc->mc_top] = mp;
+                       if (m3->mc_pg[csrc->mc_top] == psrc) {
+                               m3->mc_pg[csrc->mc_top] = pdst;
                                m3->mc_ki[csrc->mc_top] += nkeys;
                        }
                }