Example #1
0
/*
 * __wt_btcur_next --
 *	Move to the next record in the tree.
 */
int
__wt_btcur_next(WT_CURSOR_BTREE *cbt, bool truncating)
{
	WT_CURSOR *cursor;
	WT_DECL_RET;
	WT_PAGE *page;
	WT_SESSION_IMPL *session;
	uint32_t flags;
	bool newpage;

	cursor = &cbt->iface;
	session = (WT_SESSION_IMPL *)cbt->iface.session;

	WT_STAT_CONN_INCR(session, cursor_next);
	WT_STAT_DATA_INCR(session, cursor_next);

	F_CLR(cursor, WT_CURSTD_KEY_SET | WT_CURSTD_VALUE_SET);

	WT_RET(__cursor_func_init(cbt, false));

	/*
	 * If we aren't already iterating in the right direction, there's
	 * some setup to do.
	 */
	if (!F_ISSET(cbt, WT_CBT_ITERATE_NEXT))
		__wt_btcur_iterate_setup(cbt);

	/*
	 * Walk any page we're holding until the underlying call returns not-
	 * found.  Then, move to the next page, until we reach the end of the
	 * file.
	 */
	flags = WT_READ_SKIP_INTL;			/* tree walk flags */
	if (truncating)
		LF_SET(WT_READ_TRUNCATE);
	for (newpage = false;; newpage = true) {
		page = cbt->ref == NULL ? NULL : cbt->ref->page;

		if (F_ISSET(cbt, WT_CBT_ITERATE_APPEND)) {
			switch (page->type) {
			case WT_PAGE_COL_FIX:
				ret = __cursor_fix_append_next(cbt, newpage);
				break;
			case WT_PAGE_COL_VAR:
				ret = __cursor_var_append_next(cbt, newpage);
				break;
			WT_ILLEGAL_VALUE_ERR(session);
			}
			if (ret == 0)
				break;
			F_CLR(cbt, WT_CBT_ITERATE_APPEND);
			if (ret != WT_NOTFOUND)
				break;
		} else if (page != NULL) {
			switch (page->type) {
			case WT_PAGE_COL_FIX:
				ret = __cursor_fix_next(cbt, newpage);
				break;
			case WT_PAGE_COL_VAR:
				ret = __cursor_var_next(cbt, newpage);
				break;
			case WT_PAGE_ROW_LEAF:
				ret = __cursor_row_next(cbt, newpage);
				break;
			WT_ILLEGAL_VALUE_ERR(session);
			}
			if (ret != WT_NOTFOUND)
				break;

			/*
			 * Column-store pages may have appended entries. Handle
			 * it separately from the usual cursor code, it's in a
			 * simple format.
			 */
			if (page->type != WT_PAGE_ROW_LEAF &&
			    (cbt->ins_head = WT_COL_APPEND(page)) != NULL) {
				F_SET(cbt, WT_CBT_ITERATE_APPEND);
				continue;
			}
		}

		/*
		 * If we saw a lot of deleted records on this page, or we went
		 * all the way through a page and only saw deleted records, try
		 * to evict the page when we release it.  Otherwise repeatedly
		 * deleting from the beginning of a tree can have quadratic
		 * performance.  Take care not to force eviction of pages that
		 * are genuinely empty, in new trees.
		 */
		if (page != NULL &&
		    (cbt->page_deleted_count > WT_BTREE_DELETE_THRESHOLD ||
		    (newpage && cbt->page_deleted_count > 0)))
			__wt_page_evict_soon(session, cbt->ref);
		cbt->page_deleted_count = 0;

		WT_ERR(__wt_tree_walk(session, &cbt->ref, flags));
		WT_ERR_TEST(cbt->ref == NULL, WT_NOTFOUND);
	}

#ifdef HAVE_DIAGNOSTIC
	if (ret == 0)
		WT_ERR(__wt_cursor_key_order_check(session, cbt, true));
#endif
	if (ret == 0)
		F_SET(cursor, WT_CURSTD_KEY_INT | WT_CURSTD_VALUE_INT);

err:	if (ret != 0)
		WT_TRET(__cursor_reset(cbt));
	return (ret);
}
Example #2
0
/*
 * __wt_btcur_next --
 *	Move to the next record in the tree.
 */
int
__wt_btcur_next(WT_CURSOR_BTREE *cbt, int discard)
{
	WT_DECL_RET;
	WT_PAGE *page;
	WT_SESSION_IMPL *session;
	uint32_t flags;
	int newpage;

	session = (WT_SESSION_IMPL *)cbt->iface.session;

	WT_STAT_FAST_CONN_INCR(session, cursor_next);
	WT_STAT_FAST_DATA_INCR(session, cursor_next);

	flags = WT_TREE_SKIP_INTL;			/* Tree walk flags. */
	if (discard)
		LF_SET(WT_TREE_DISCARD);

	WT_RET(__cursor_func_init(cbt, 0));

	/*
	 * If we aren't already iterating in the right direction, there's
	 * some setup to do.
	 */
	if (!F_ISSET(cbt, WT_CBT_ITERATE_NEXT))
		__wt_btcur_iterate_setup(cbt, 1);

	page = cbt->page;

	/*
	 * Walk any page we're holding until the underlying call returns not-
	 * found.  Then, move to the next page, until we reach the end of the
	 * file.
	 */
	for (newpage = 0;; newpage = 1) {
		if (F_ISSET(cbt, WT_CBT_ITERATE_APPEND)) {
			switch (page->type) {
			case WT_PAGE_COL_FIX:
				ret = __cursor_fix_append_next(cbt, newpage);
				break;
			case WT_PAGE_COL_VAR:
				ret = __cursor_var_append_next(cbt, newpage);
				break;
			WT_ILLEGAL_VALUE_ERR(session);
			}
			if (ret == 0)
				break;
			F_CLR(cbt, WT_CBT_ITERATE_APPEND);
			if (ret != WT_NOTFOUND)
				break;
		} else if (page != NULL) {
			switch (page->type) {
			case WT_PAGE_COL_FIX:
				ret = __cursor_fix_next(cbt, newpage);
				break;
			case WT_PAGE_COL_VAR:
				ret = __cursor_var_next(cbt, newpage);
				break;
			case WT_PAGE_ROW_LEAF:
				ret = __cursor_row_next(cbt, newpage);
				break;
			WT_ILLEGAL_VALUE_ERR(session);
			}
			if (ret != WT_NOTFOUND)
				break;

			/*
			 * The last page in a column-store has appended entries.
			 * We handle it separately from the usual cursor code:
			 * it's only that one page and it's in a simple format.
			 */
			if (page->type != WT_PAGE_ROW_LEAF &&
			    (cbt->ins_head = WT_COL_APPEND(page)) != NULL) {
				F_SET(cbt, WT_CBT_ITERATE_APPEND);
				continue;
			}
		}

		cbt->page = NULL;
		WT_ERR(__wt_tree_walk(session, &page, flags));
		WT_ERR_TEST(page == NULL, WT_NOTFOUND);
		WT_ASSERT(session,
		    page->type != WT_PAGE_COL_INT &&
		    page->type != WT_PAGE_ROW_INT);
		cbt->page = page;
	}

err:	if (ret != 0)
		WT_TRET(__cursor_error_resolve(cbt));
	return (ret);
}
Example #3
0
/*将btree cursor移动到下一个记录*/
int __wt_btcur_next(WT_CURSOR_BTREE *cbt, int truncating)
{
	WT_DECL_RET;
	WT_PAGE *page;
	WT_SESSION_IMPL *session;
	uint32_t flags;
	int newpage;

	session = (WT_SESSION_IMPL *)cbt->iface.session;

	WT_STAT_FAST_CONN_INCR(session, cursor_next);
	WT_STAT_FAST_DATA_INCR(session, cursor_next);

	/*btree 扫描标示*/
	flags = WT_READ_SKIP_INTL;
	if (truncating)
		LF_SET(WT_READ_TRUNCATE);

	/*激活一个btree cursor*/
	WT_RET(__cursor_func_init(cbt, 0));

	/*初始化cursor*/
	if (!F_ISSET(cbt, WT_CBT_ITERATE_NEXT))
		__wt_btcur_iterate_setup(cbt, 1);

	/*对btree的扫描*/
	for (;;){
		page = cbt->ref == NULL ? NULL : cbt->ref->page;
		WT_ASSERT(session, page == NULL || !WT_PAGE_IS_INTERNAL(page));

		/*column store append方式,在insert header上做扫描*/
		if (F_ISSET(cbt, WT_CBT_ITERATE_APPEND)){
			switch (page->type){
			case WT_PAGE_COL_FIX:
				ret = __cursor_fix_append_next(cbt, newpage);
				break;
			case WT_PAGE_COL_VAR:
				ret = __cursor_var_append_next(cbt, newpage);
				break;
				WT_ILLEGAL_VALUE_ERR(session);
			}

			if (ret == 0)
				break;

			/*清除掉column store的标记*/
			F_CLR(cbt, WT_CBT_ITERATE_APPEND);
			if (ret != WT_NOTFOUND)
				break;
		}
		else if (page != NULL){
			switch (page->type) {
			case WT_PAGE_COL_FIX:
				ret = __cursor_fix_next(cbt, newpage);
				break;
			case WT_PAGE_COL_VAR:
				ret = __cursor_var_next(cbt, newpage);
				break;
			case WT_PAGE_ROW_LEAF:
				ret = __cursor_row_next(cbt, newpage);
				break;
			WT_ILLEGAL_VALUE_ERR(session);
			}

			/*找到对应的记录了,直接返回*/
			if (ret != WT_NOTFOUND)
				break;

			/*假如是column store方式,检查是否要扫描insert header list*/
			if (page->type != WT_PAGE_ROW_LEAF && (cbt->ins_head = WT_COL_APPEND(page)) != NULL) {
				F_SET(cbt, WT_CBT_ITERATE_APPEND);
				continue;
			}
		}

		/*删除的记录太多,对page进行重组,增大page的填充因子*/
		if (page != NULL && (cbt->page_deleted_count > WT_BTREE_DELETE_THRESHOLD || (newpage && cbt->page_deleted_count > 0))){
			__wt_page_evict_soon(page);
		}

		cbt->page_deleted_count = 0;

		/*btree cursor跳转到下一个page上*/
		WT_ERR(__wt_tree_walk(session, &cbt->ref, NULL, flags));
		WT_ERR_TEST(cbt->ref == NULL, WT_NOTFOUND);
	}

err:
	if (ret != 0) /*失败了,恢复cursor的状态*/
		WT_TRET(__cursor_reset(cbt));

	return ret;
}
Example #4
0
/*
 * __wt_btcur_next --
 *	Move to the next record in the tree.
 */
int
__wt_btcur_next(WT_CURSOR_BTREE *cbt, int truncating)
{
	WT_DECL_RET;
	WT_PAGE *page;
	WT_SESSION_IMPL *session;
	uint32_t flags;
	int skipped, newpage;

	session = (WT_SESSION_IMPL *)cbt->iface.session;

	WT_STAT_FAST_CONN_INCR(session, cursor_next);
	WT_STAT_FAST_DATA_INCR(session, cursor_next);

	flags = WT_READ_SKIP_INTL;			/* Tree walk flags. */
	if (truncating)
		LF_SET(WT_READ_TRUNCATE);

	WT_RET(__cursor_func_init(cbt, 0));

	/*
	 * If we aren't already iterating in the right direction, there's
	 * some setup to do.
	 */
	if (!F_ISSET(cbt, WT_CBT_ITERATE_NEXT))
		__wt_btcur_iterate_setup(cbt, 1);

	/*
	 * Walk any page we're holding until the underlying call returns not-
	 * found.  Then, move to the next page, until we reach the end of the
	 * file.
	 */
	for (skipped = newpage = 0;; skipped = 0, newpage = 1) {
		page = cbt->ref == NULL ? NULL : cbt->ref->page;
		WT_ASSERT(session, page == NULL || !WT_PAGE_IS_INTERNAL(page));

		if (F_ISSET(cbt, WT_CBT_ITERATE_APPEND)) {
			switch (page->type) {
			case WT_PAGE_COL_FIX:
				ret = __cursor_fix_append_next(cbt, newpage);
				break;
			case WT_PAGE_COL_VAR:
				ret = __cursor_var_append_next(
				    cbt, newpage, &skipped);
				break;
			WT_ILLEGAL_VALUE_ERR(session);
			}
			if (ret == 0)
				break;
			F_CLR(cbt, WT_CBT_ITERATE_APPEND);
			if (ret != WT_NOTFOUND)
				break;
		} else if (page != NULL) {
			switch (page->type) {
			case WT_PAGE_COL_FIX:
				ret = __cursor_fix_next(cbt, newpage);
				break;
			case WT_PAGE_COL_VAR:
				ret = __cursor_var_next(cbt, newpage, &skipped);
				break;
			case WT_PAGE_ROW_LEAF:
				ret = __cursor_row_next(cbt, newpage, &skipped);
				break;
			WT_ILLEGAL_VALUE_ERR(session);
			}
			if (ret != WT_NOTFOUND)
				break;

			/*
			 * The last page in a column-store has appended entries.
			 * We handle it separately from the usual cursor code:
			 * it's only that one page and it's in a simple format.
			 */
			if (page->type != WT_PAGE_ROW_LEAF &&
			    (cbt->ins_head = WT_COL_APPEND(page)) != NULL) {
				F_SET(cbt, WT_CBT_ITERATE_APPEND);
				continue;
			}
		}

		/*
		 * If we scanned all the way through a page and only saw
		 * deleted records, try to evict the page as we release it.
		 * Otherwise repeatedly deleting from the beginning of a tree
		 * can have quadratic performance.
		 */
		if (newpage && skipped)
			page->read_gen = WT_READGEN_OLDEST;

		WT_ERR(__wt_tree_walk(session, &cbt->ref, flags));
		WT_ERR_TEST(cbt->ref == NULL, WT_NOTFOUND);
	}

err:	if (ret != 0)
		WT_TRET(__cursor_reset(cbt));
	return (ret);
}