WT-2558: WT_PAGE structure is 72B, reduce to 64B.

Move the row-store insert and update structures into the WT_PAGE_MODIFY
structure.

7 files changed, 81 insertions, 78 deletions

diff --git a/src/btree/bt_cursor.c b/src/btree/bt_cursor.c
index 839a829b960..e61832a49e5 100644
--- a/src/btree/bt_cursor.c
+++ b/src/btree/bt_cursor.c
@@ -168,8 +168,8 @@ __cursor_valid(WT_CURSOR_BTREE *cbt, WT_UPDATE **updp)
 			return (false);
 
 		/*
-		 * Updates aren't stored on the page, an update would have
-		 * appeared as an "insert" object; no further checks to do.
+		 * An update would have appeared as an "insert" object; no
+		 * further checks to do.
 		 */
 		break;
 	case BTREE_COL_VAR:
@@ -179,19 +179,18 @@ __cursor_valid(WT_CURSOR_BTREE *cbt, WT_UPDATE **updp)
 		WT_ASSERT(session, cbt->slot < page->pg_var_entries);
 
 		/*
-		 * Column-store updates aren't stored on the page, instead they
-		 * are stored as "insert" objects. If search returned an insert
-		 * object we can't return, the returned on-page object must be
-		 * checked for a match.
+		 * Column-store updates are stored as "insert" objects. If
+		 * search returned an insert object we can't return, the
+		 * returned on-page object must be checked for a match.
 		 */
 		if (cbt->ins != NULL && !F_ISSET(cbt, WT_CBT_VAR_ONPAGE_MATCH))
 			return (false);
 
 		/*
-		 * Updates aren't stored on the page, an update would have
-		 * appeared as an "insert" object; however, variable-length
-		 * column store deletes are written into the backing store,
-		 * check the cell for a record already deleted when read.
+		 * Although updates would have appeared as an "insert" objects,
+		 * variable-length column store deletes are written into the
+		 * backing store; check the cell for a record already deleted
+		 * when read.
 		 */
 		cip = &page->pg_var_d[cbt->slot];
 		if ((cell = WT_COL_PTR(page, cip)) == NULL ||
@@ -211,9 +210,11 @@ __cursor_valid(WT_CURSOR_BTREE *cbt, WT_UPDATE **updp)
 		if (cbt->ins != NULL)
 			return (false);
 
-		/* Updates are stored on the page, check for a delete. */
-		if (page->pg_row_upd != NULL && (upd = __wt_txn_read(
-		    session, page->pg_row_upd[cbt->slot])) != NULL) {
+		/* Check for an update. */
+		if (page->modify != NULL &&
+		    page->modify->mod_row_update != NULL &&
+		    (upd = __wt_txn_read(session,
+		    page->modify->mod_row_update[cbt->slot])) != NULL) {
 			if (WT_UPDATE_DELETED_ISSET(upd))
 				return (false);
 			if (updp != NULL)
@@ -596,9 +597,12 @@ __curfile_update_check(WT_CURSOR_BTREE *cbt)
 		return (0);
 	if (cbt->ins != NULL)
 		return (__wt_txn_update_check(session, cbt->ins->upd));
-	if (btree->type == BTREE_ROW && cbt->ref->page->pg_row_upd != NULL)
-		return (__wt_txn_update_check(
-		    session, cbt->ref->page->pg_row_upd[cbt->slot]));
+
+	if (btree->type == BTREE_ROW &&
+	    cbt->ref->page->modify != NULL &&
+	    cbt->ref->page->modify->mod_row_update != NULL)
+		return (__wt_txn_update_check(session,
+		    cbt->ref->page->modify->mod_row_update[cbt->slot]));
 	return (0);
 }
 
diff --git a/src/btree/bt_delete.c b/src/btree/bt_delete.c
index ba16dd204e8..54b7fedb31d 100644
--- a/src/btree/bt_delete.c
+++ b/src/btree/bt_delete.c
@@ -288,10 +288,9 @@ __wt_delete_page_instantiate(WT_SESSION_IMPL *session, WT_REF *ref)
 	 * read-only or if the application never modifies the tree, we're not
 	 * able to do so.)
 	 */
-	if (btree->modified) {
-		WT_RET(__wt_page_modify_init(session, page));
+	WT_RET(__wt_page_modify_init(session, page));
+	if (btree->modified)
 		__wt_page_modify_set(session, page);
-	}
 
 	/*
 	 * An operation is accessing a "deleted" page, and we're building an
@@ -326,7 +325,7 @@ __wt_delete_page_instantiate(WT_SESSION_IMPL *session, WT_REF *ref)
 
 	/* Allocate the per-page update array. */
 	WT_ERR(__wt_calloc_def(session, page->pg_row_entries, &upd_array));
-	page->pg_row_upd = upd_array;
+	page->modify->mod_row_update = upd_array;
 
 	/*
 	 * Fill in the per-reference update array with references to update
diff --git a/src/btree/bt_discard.c b/src/btree/bt_discard.c
index 4674efe8c44..509333551c4 100644
--- a/src/btree/bt_discard.c
+++ b/src/btree/bt_discard.c
@@ -204,6 +204,23 @@ __free_page_modify(WT_SESSION_IMPL *session, WT_PAGE *page)
 			    WT_PAGE_COL_FIX ? 1 : page->pg_var_entries,
 			    update_ignore);
 		break;
+	case WT_PAGE_ROW_LEAF:
+		/*
+		 * Free the insert array.
+		 *
+		 * Row-store tables have one additional slot in the insert array
+		 * (the insert array has an extra slot to hold keys that sort
+		 * before keys found on the original page).
+		 */
+		if (mod->mod_row_insert != NULL)
+			__free_skip_array(session, mod->mod_row_insert,
+			    page->pg_row_entries + 1, update_ignore);
+
+		/* Free the update array. */
+		if (mod->mod_row_update != NULL)
+			__free_update(session, mod->mod_row_update,
+			    page->pg_row_entries, update_ignore);
+		break;
 	}
 
 	/* Free the overflow on-page, reuse and transaction-cache skiplists. */
@@ -324,10 +341,6 @@ __free_page_row_leaf(WT_SESSION_IMPL *session, WT_PAGE *page)
 	WT_ROW *rip;
 	uint32_t i;
 	void *copy;
-	bool update_ignore;
-
-	/* In some failed-split cases, we can't discard updates. */
-	update_ignore = F_ISSET_ATOMIC(page, WT_PAGE_UPDATE_IGNORE);
 
 	/*
 	 * Free the in-memory index array.
@@ -342,22 +355,6 @@ __free_page_row_leaf(WT_SESSION_IMPL *session, WT_PAGE *page)
 		    page, copy, &ikey, NULL, NULL, NULL);
 		__wt_free(session, ikey);
 	}
-
-	/*
-	 * Free the insert array.
-	 *
-	 * Row-store tables have one additional slot in the insert array (the
-	 * insert array has an extra slot to hold keys that sort before keys
-	 * found on the original page).
-	 */
-	if (page->pg_row_ins != NULL)
-		__free_skip_array(session,
-		    page->pg_row_ins, page->pg_row_entries + 1, update_ignore);
-
-	/* Free the update array. */
-	if (page->pg_row_upd != NULL)
-		__free_update(session,
-		    page->pg_row_upd, page->pg_row_entries, update_ignore);
 }
 
 /*
diff --git a/src/btree/bt_split.c b/src/btree/bt_split.c
index d06ad1d34e7..341bc0309d9 100644
--- a/src/btree/bt_split.c
+++ b/src/btree/bt_split.c
@@ -1520,7 +1520,7 @@ __split_multi_inmem(
 			/* Build a key. */
 			if (supd->ins == NULL) {
 				slot = WT_ROW_SLOT(orig, supd->rip);
-				upd = orig->pg_row_upd[slot];
+				upd = orig->modify->mod_row_update[slot];
 
 				WT_ERR(__wt_row_leaf_key(
 				    session, orig, supd->rip, key, false));
@@ -1583,7 +1583,7 @@ __split_multi_inmem_final(WT_PAGE *orig, WT_MULTI *multi)
 		case WT_PAGE_ROW_LEAF:
 			if (supd->ins == NULL) {
 				slot = WT_ROW_SLOT(orig, supd->rip);
-				orig->pg_row_upd[slot] = NULL;
+				orig->modify->mod_row_update[slot] = NULL;
 			} else
 				supd->ins->upd = NULL;
 			break;
@@ -1783,8 +1783,10 @@ __split_insert(WT_SESSION_IMPL *session, WT_REF *ref)
 	__wt_page_modify_set(session, right);
 
 	if (type == WT_PAGE_ROW_LEAF) {
-		WT_ERR(__wt_calloc_one(session, &right->pg_row_ins));
-		WT_ERR(__wt_calloc_one(session, &right->pg_row_ins[0]));
+		WT_ERR(__wt_calloc_one(
+		    session, &right->modify->mod_row_insert));
+		WT_ERR(__wt_calloc_one(
+		    session, &right->modify->mod_row_insert[0]));
 	} else {
 		WT_ERR(__wt_calloc_one(
 		    session, &right->modify->mod_col_append));
@@ -1840,7 +1842,7 @@ __split_insert(WT_SESSION_IMPL *session, WT_REF *ref)
 	 * can be ignored.)
 	 */
 	tmp_ins_head = type == WT_PAGE_ROW_LEAF ?
-	    right->pg_row_ins[0] : right->modify->mod_col_append[0];
+	    right->modify->mod_row_insert[0] : right->modify->mod_col_append[0];
 	tmp_ins_head->head[0] = tmp_ins_head->tail[0] = moved_ins;
 
 	/*
@@ -1975,8 +1977,8 @@ __split_insert(WT_SESSION_IMPL *session, WT_REF *ref)
 	 * lists have.
 	 */
 	if (type == WT_PAGE_ROW_LEAF)
-		right->pg_row_ins[0]->head[0] =
-		    right->pg_row_ins[0]->tail[0] = NULL;
+		right->modify->mod_row_insert[0]->head[0] =
+		    right->modify->mod_row_insert[0]->tail[0] = NULL;
 	else
 		right->modify->mod_col_append[0]->head[0] =
 		    right->modify->mod_col_append[0]->tail[0] = NULL;
diff --git a/src/btree/row_modify.c b/src/btree/row_modify.c
index 176016bb340..f0424ff93b4 100644
--- a/src/btree/row_modify.c
+++ b/src/btree/row_modify.c
@@ -53,6 +53,7 @@ __wt_row_modify(WT_SESSION_IMPL *session, WT_CURSOR_BTREE *cbt,
 	WT_INSERT *ins;
 	WT_INSERT_HEAD *ins_head, **ins_headp;
 	WT_PAGE *page;
+	WT_PAGE_MODIFY *mod;
 	WT_UPDATE *old_upd, *upd, **upd_entry;
 	size_t ins_size, upd_size;
 	uint32_t ins_slot;
@@ -70,6 +71,7 @@ __wt_row_modify(WT_SESSION_IMPL *session, WT_CURSOR_BTREE *cbt,
 
 	/* If we don't yet have a modify structure, we'll need one. */
 	WT_RET(__wt_page_modify_init(session, page));
+	mod = page->modify;
 
 	/*
 	 * Modify: allocate an update array as necessary, build a WT_UPDATE
@@ -83,11 +85,12 @@ __wt_row_modify(WT_SESSION_IMPL *session, WT_CURSOR_BTREE *cbt,
 	if (cbt->compare == 0) {
 		if (cbt->ins == NULL) {
 			/* Allocate an update array as necessary. */
-			WT_PAGE_ALLOC_AND_SWAP(session, page,
-			    page->pg_row_upd, upd_entry, page->pg_row_entries);
+			WT_PAGE_ALLOC_AND_SWAP(session,
+			    page, mod->mod_row_update,
+			    upd_entry, page->pg_row_entries);
 
 			/* Set the WT_UPDATE array reference. */
-			upd_entry = &page->pg_row_upd[cbt->slot];
+			upd_entry = &mod->mod_row_update[cbt->slot];
 		} else
 			upd_entry = &cbt->ins->upd;
 
@@ -144,11 +147,11 @@ __wt_row_modify(WT_SESSION_IMPL *session, WT_CURSOR_BTREE *cbt,
 		 * slot.  That's hard, so we set a flag.
 		 */
 		WT_PAGE_ALLOC_AND_SWAP(session, page,
-		    page->pg_row_ins, ins_headp, page->pg_row_entries + 1);
+		    mod->mod_row_insert, ins_headp, page->pg_row_entries + 1);
 
 		ins_slot = F_ISSET(cbt, WT_CBT_SEARCH_SMALLEST) ?
 		    page->pg_row_entries: cbt->slot;
-		ins_headp = &page->pg_row_ins[ins_slot];
+		ins_headp = &mod->mod_row_insert[ins_slot];
 
 		/* Allocate the WT_INSERT_HEAD structure as necessary. */
 		WT_PAGE_ALLOC_AND_SWAP(session, page, *ins_headp, ins_head, 1);
diff --git a/src/include/btmem.h b/src/include/btmem.h
index 0b43a3f7302..9700b6f4761 100644
--- a/src/include/btmem.h
+++ b/src/include/btmem.h
@@ -355,6 +355,17 @@ struct __wt_page_modify {
 #define	mod_col_update		u2.column_leaf.update
 #undef	mod_col_split_recno
 #define	mod_col_split_recno	u2.column_leaf.split_recno
+	struct {
+		/* Inserted items for row-store. */
+		WT_INSERT_HEAD	**insert;
+
+		/* Updated items for row-stores. */
+		WT_UPDATE	**update;
+	} row_leaf;
+#undef	mod_row_insert
+#define	mod_row_insert		u2.row_leaf.insert
+#undef	mod_row_update
+#define	mod_row_update		u2.row_leaf.update
 	} u2;
 
 	/*
@@ -487,28 +498,11 @@ struct __wt_page {
 
 		/* Row-store leaf page. */
 		struct {
-			/*
-			 * The column-store leaf page modification structures
-			 * live in the WT_PAGE_MODIFY structure to keep the
-			 * WT_PAGE structure as small as possible for read-only
-			 * pages.  For consistency, we could move the row-store
-			 * modification structures into WT_PAGE_MODIFY too, but
-			 * that doesn't shrink WT_PAGE any further and it would
-			 * require really ugly naming inside of WT_PAGE_MODIFY
-			 * to avoid growing that structure.
-			 */
-			WT_INSERT_HEAD	**ins;	/* Inserts */
-			WT_UPDATE	**upd;	/* Updates */
-
 			WT_ROW *d;		/* Key/value pairs */
 			uint32_t entries;	/* Entries */
 		} row;
 #undef	pg_row_d
 #define	pg_row_d	u.row.d
-#undef	pg_row_ins
-#define	pg_row_ins	u.row.ins
-#undef	pg_row_upd
-#define	pg_row_upd	u.row.upd
 #undef	pg_row_entries
 #define	pg_row_entries	u.row.entries
 
@@ -1008,12 +1002,15 @@ struct __wt_insert_head {
  * of pointers and the specific structure exist, else NULL.
  */
 #define	WT_ROW_INSERT_SLOT(page, slot)					\
-	((page)->pg_row_ins == NULL ? NULL : (page)->pg_row_ins[slot])
+	((page)->modify == NULL ||					\
+	    (page)->modify->mod_row_insert == NULL ?			\
+	    NULL : (page)->modify->mod_row_insert[slot])
 #define	WT_ROW_INSERT(page, ip)						\
 	WT_ROW_INSERT_SLOT(page, WT_ROW_SLOT(page, ip))
 #define	WT_ROW_UPDATE(page, ip)						\
-	((page)->pg_row_upd == NULL ?					\
-	    NULL : (page)->pg_row_upd[WT_ROW_SLOT(page, ip)])
+	((page)->modify == NULL ||					\
+	    (page)->modify->mod_row_update == NULL ?			\
+	    NULL : (page)->modify->mod_row_update[WT_ROW_SLOT(page, ip)])
 /*
  * WT_ROW_INSERT_SMALLEST references an additional slot past the end of the
  * the "one per WT_ROW slot" insert array.  That's because the insert array
@@ -1021,8 +1018,9 @@ struct __wt_insert_head {
  * original page.
  */
 #define	WT_ROW_INSERT_SMALLEST(page)					\
-	((page)->pg_row_ins == NULL ?					\
-	    NULL : (page)->pg_row_ins[(page)->pg_row_entries])
+	((page)->modify == NULL ||					\
+	    (page)->modify->mod_row_insert == NULL ?			\
+	    NULL : (page)->modify->mod_row_insert[(page)->pg_row_entries])
 
 /*
  * The column-store leaf page update lists are arrays of pointers to structures,
@@ -1048,9 +1046,9 @@ struct __wt_insert_head {
  * appends.
  */
 #define	WT_COL_APPEND(page)						\
-	((page)->modify != NULL &&					\
-	    (page)->modify->mod_col_append != NULL ?			\
-	    (page)->modify->mod_col_append[0] : NULL)
+	((page)->modify == NULL ||					\
+	    (page)->modify->mod_col_append == NULL ?			\
+	    NULL : (page)->modify->mod_col_append[0])
 
 /* WT_FIX_FOREACH walks fixed-length bit-fields on a disk page. */
 #define	WT_FIX_FOREACH(btree, dsk, v, i)				\
diff --git a/src/reconcile/rec_write.c b/src/reconcile/rec_write.c
index 06550065c27..05225db8a94 100644
--- a/src/reconcile/rec_write.c
+++ b/src/reconcile/rec_write.c
@@ -3431,7 +3431,7 @@ __rec_update_las(WT_SESSION_IMPL *session,
 		case WT_PAGE_ROW_LEAF:
 			if (list->ins == NULL) {
 				slot = WT_ROW_SLOT(page, list->rip);
-				upd = page->pg_row_upd[slot];
+				upd = page->modify->mod_row_update[slot];
 			} else
 				upd = list->ins->upd;
 			break;