/****************************************************** The B-tree (c) 1994-1996 Innobase Oy Created 6/2/1994 Heikki Tuuri *******************************************************/ #include "btr0btr.h" #ifdef UNIV_NONINL #include "btr0btr.ic" #endif #include "fsp0fsp.h" #include "page0page.h" #include "btr0cur.h" #include "btr0sea.h" #include "btr0pcur.h" #include "rem0cmp.h" #include "lock0lock.h" #include "ibuf0ibuf.h" /* Node pointers ------------- Leaf pages of a B-tree contain the index records stored in the tree. On levels n > 0 we store 'node pointers' to pages on level n - 1. For each page there is exactly one node pointer stored: thus the our tree is an ordinary B-tree, not a B-link tree. A node pointer contains a prefix P of an index record. The prefix is long enough so that it determines an index record uniquely. The file page number of the child page is added as the last field. To the child page we can store node pointers or index records which are >= P in the alphabetical order, but < P1 if there is a next node pointer on the level, and P1 is its prefix. If a node pointer with a prefix P points to a non-leaf child, then the leftmost record in the child must have the same prefix P. If it points to a leaf node, the child is not required to contain any record with a prefix equal to P. The leaf case is decided this way to allow arbitrary deletions in a leaf node without touching upper levels of the tree. We have predefined a special minimum record which we define as the smallest record in any alphabetical order. A minimum record is denoted by setting a bit in the record header. A minimum record acts as the prefix of a node pointer which points to a leftmost node on any level of the tree. File page allocation -------------------- In the root node of a B-tree there are two file segment headers. The leaf pages of a tree are allocated from one file segment, to make them consecutive on disk if possible. From the other file segment we allocate pages for the non-leaf levels of the tree. */ /* If this many inserts occur sequentially, it affects page split */ #define BTR_PAGE_SEQ_INSERT_LIMIT 5 /****************************************************************** Creates a new index page to the tree (not the root, and also not used in page reorganization). */ static void btr_page_create( /*============*/ page_t* page, /* in: page to be created */ dict_tree_t* tree, /* in: index tree */ mtr_t* mtr); /* in: mtr */ /****************************************************************** Sets the child node file address in a node pointer. */ UNIV_INLINE void btr_node_ptr_set_child_page_no( /*===========================*/ rec_t* rec, /* in: node pointer record */ ulint page_no, /* in: child node address */ mtr_t* mtr); /* in: mtr */ /**************************************************************** Returns the upper level node pointer to a page. It is assumed that mtr holds an x-latch on the tree. */ static rec_t* btr_page_get_father_node_ptr( /*=========================*/ /* out: pointer to node pointer record */ dict_tree_t* tree, /* in: index tree */ page_t* page, /* in: page: must contain at least one user record */ mtr_t* mtr); /* in: mtr */ /***************************************************************** Empties an index page. */ static void btr_page_empty( /*===========*/ page_t* page, /* in: page to be emptied */ mtr_t* mtr); /* in: mtr */ /***************************************************************** Returns TRUE if the insert fits on the appropriate half-page with the chosen split_rec. */ static ibool btr_page_insert_fits( /*=================*/ /* out: TRUE if fits */ btr_cur_t* cursor, /* in: cursor at which insert should be made */ rec_t* split_rec, /* in: suggestion for first record on upper half-page, or NULL if tuple should be first */ dtuple_t* tuple); /* in: tuple to insert */ /****************************************************************** Gets the root node of a tree and x-latches it. */ static page_t* btr_root_get( /*=========*/ /* out: root page, x-latched */ dict_tree_t* tree, /* in: index tree */ mtr_t* mtr) /* in: mtr */ { ulint space; ulint root_page_no; page_t* root; ut_ad(mtr_memo_contains(mtr, dict_tree_get_lock(tree), MTR_MEMO_X_LOCK) || mtr_memo_contains(mtr, dict_tree_get_lock(tree), MTR_MEMO_S_LOCK)); space = dict_tree_get_space(tree); root_page_no = dict_tree_get_page(tree); root = btr_page_get(space, root_page_no, RW_X_LATCH, mtr); return(root); } /***************************************************************** Gets pointer to the previous user record in the tree. It is assumed that the caller has appropriate latches on the page and its neighbor. */ rec_t* btr_get_prev_user_rec( /*==================*/ /* out: previous user record, NULL if there is none */ rec_t* rec, /* in: record on leaf level */ mtr_t* mtr) /* in: mtr holding a latch on the page, and if needed, also to the previous page */ { page_t* page; page_t* prev_page; ulint prev_page_no; rec_t* prev_rec; ulint space; page = buf_frame_align(rec); if (page_get_infimum_rec(page) != rec) { prev_rec = page_rec_get_prev(rec); if (page_get_infimum_rec(page) != prev_rec) { return(prev_rec); } } prev_page_no = btr_page_get_prev(page, mtr); space = buf_frame_get_space_id(page); if (prev_page_no != FIL_NULL) { prev_page = buf_page_get_with_no_latch(space, prev_page_no, mtr); /* The caller must already have a latch to the brother */ ut_ad((mtr_memo_contains(mtr, buf_block_align(prev_page), MTR_MEMO_PAGE_S_FIX)) || (mtr_memo_contains(mtr, buf_block_align(prev_page), MTR_MEMO_PAGE_X_FIX))); prev_rec = page_rec_get_prev(page_get_supremum_rec(prev_page)); return(prev_rec); } return(NULL); } /***************************************************************** Gets pointer to the next user record in the tree. It is assumed that the caller has appropriate latches on the page and its neighbor. */ rec_t* btr_get_next_user_rec( /*==================*/ /* out: next user record, NULL if there is none */ rec_t* rec, /* in: record on leaf level */ mtr_t* mtr) /* in: mtr holding a latch on the page, and if needed, also to the next page */ { page_t* page; page_t* next_page; ulint next_page_no; rec_t* next_rec; ulint space; page = buf_frame_align(rec); if (page_get_supremum_rec(page) != rec) { next_rec = page_rec_get_next(rec); if (page_get_supremum_rec(page) != next_rec) { return(next_rec); } } next_page_no = btr_page_get_next(page, mtr); space = buf_frame_get_space_id(page); if (next_page_no != FIL_NULL) { next_page = buf_page_get_with_no_latch(space, next_page_no, mtr); /* The caller must already have a latch to the brother */ ut_ad((mtr_memo_contains(mtr, buf_block_align(next_page), MTR_MEMO_PAGE_S_FIX)) || (mtr_memo_contains(mtr, buf_block_align(next_page), MTR_MEMO_PAGE_X_FIX))); next_rec = page_rec_get_next(page_get_infimum_rec(next_page)); return(next_rec); } return(NULL); } /****************************************************************** Creates a new index page to the tree (not the root, and also not used in page reorganization). */ static void btr_page_create( /*============*/ page_t* page, /* in: page to be created */ dict_tree_t* tree, /* in: index tree */ mtr_t* mtr) /* in: mtr */ { ut_ad(mtr_memo_contains(mtr, buf_block_align(page), MTR_MEMO_PAGE_X_FIX)); page_create(page, mtr); btr_page_set_index_id(page, tree->id, mtr); } /****************************************************************** Allocates a new file page to be used in an ibuf tree. Takes the page from the free list of the tree, which must contain pages! */ static page_t* btr_page_alloc_for_ibuf( /*====================*/ /* out: new allocated page, x-latched */ dict_tree_t* tree, /* in: index tree */ mtr_t* mtr) /* in: mtr */ { fil_addr_t node_addr; page_t* root; page_t* new_page; root = btr_root_get(tree, mtr); node_addr = flst_get_first(root + PAGE_HEADER + PAGE_BTR_IBUF_FREE_LIST, mtr); ut_a(node_addr.page != FIL_NULL); new_page = buf_page_get(dict_tree_get_space(tree), node_addr.page, RW_X_LATCH, mtr); buf_page_dbg_add_level(new_page, SYNC_TREE_NODE_NEW); flst_remove(root + PAGE_HEADER + PAGE_BTR_IBUF_FREE_LIST, new_page + PAGE_HEADER + PAGE_BTR_IBUF_FREE_LIST_NODE, mtr); ut_ad(flst_validate(root + PAGE_HEADER + PAGE_BTR_IBUF_FREE_LIST, mtr)); return(new_page); } /****************************************************************** Allocates a new file page to be used in an index tree. NOTE: we assume that the caller has made the reservation for free extents! */ page_t* btr_page_alloc( /*===========*/ /* out: new allocated page, x-latched; NULL if out of space */ dict_tree_t* tree, /* in: index tree */ ulint hint_page_no, /* in: hint of a good page */ byte file_direction, /* in: direction where a possible page split is made */ ulint level, /* in: level where the page is placed in the tree */ mtr_t* mtr) /* in: mtr */ { fseg_header_t* seg_header; page_t* root; page_t* new_page; ulint new_page_no; ut_ad(mtr_memo_contains(mtr, dict_tree_get_lock(tree), MTR_MEMO_X_LOCK)); if (tree->type & DICT_IBUF) { return(btr_page_alloc_for_ibuf(tree, mtr)); } root = btr_root_get(tree, mtr); if (level == 0) { seg_header = root + PAGE_HEADER + PAGE_BTR_SEG_LEAF; } else { seg_header = root + PAGE_HEADER + PAGE_BTR_SEG_TOP; } /* Parameter TRUE below states that the caller has made the reservation for free extents, and thus we know that a page can be allocated: */ new_page_no = fseg_alloc_free_page_general(seg_header, hint_page_no, file_direction, TRUE, mtr); if (new_page_no == FIL_NULL) { return(NULL); } new_page = buf_page_get(dict_tree_get_space(tree), new_page_no, RW_X_LATCH, mtr); buf_page_dbg_add_level(new_page, SYNC_TREE_NODE_NEW); return(new_page); } /****************************************************************** Gets the number of pages in a B-tree. */ ulint btr_get_size( /*=========*/ /* out: number of pages */ dict_index_t* index, /* in: index */ ulint flag) /* in: BTR_N_LEAF_PAGES or BTR_TOTAL_SIZE */ { fseg_header_t* seg_header; page_t* root; ulint n; ulint dummy; mtr_t mtr; mtr_start(&mtr); mtr_s_lock(dict_tree_get_lock(index->tree), &mtr); root = btr_root_get(index->tree, &mtr); if (flag == BTR_N_LEAF_PAGES) { seg_header = root + PAGE_HEADER + PAGE_BTR_SEG_LEAF; fseg_n_reserved_pages(seg_header, &n, &mtr); } else if (flag == BTR_TOTAL_SIZE) { seg_header = root + PAGE_HEADER + PAGE_BTR_SEG_TOP; n = fseg_n_reserved_pages(seg_header, &dummy, &mtr); seg_header = root + PAGE_HEADER + PAGE_BTR_SEG_LEAF; n += fseg_n_reserved_pages(seg_header, &dummy, &mtr); } else { ut_a(0); } mtr_commit(&mtr); return(n); } /****************************************************************** Frees a page used in an ibuf tree. Puts the page to the free list of the ibuf tree. */ static void btr_page_free_for_ibuf( /*===================*/ dict_tree_t* tree, /* in: index tree */ page_t* page, /* in: page to be freed, x-latched */ mtr_t* mtr) /* in: mtr */ { page_t* root; ut_ad(mtr_memo_contains(mtr, buf_block_align(page), MTR_MEMO_PAGE_X_FIX)); root = btr_root_get(tree, mtr); flst_add_first(root + PAGE_HEADER + PAGE_BTR_IBUF_FREE_LIST, page + PAGE_HEADER + PAGE_BTR_IBUF_FREE_LIST_NODE, mtr); ut_ad(flst_validate(root + PAGE_HEADER + PAGE_BTR_IBUF_FREE_LIST, mtr)); } /****************************************************************** Frees a file page used in an index tree. Can be used also to (BLOB) external storage pages, because the page level 0 can be given as an argument. */ void btr_page_free_low( /*==============*/ dict_tree_t* tree, /* in: index tree */ page_t* page, /* in: page to be freed, x-latched */ ulint level, /* in: page level */ mtr_t* mtr) /* in: mtr */ { fseg_header_t* seg_header; page_t* root; ulint space; ulint page_no; ut_ad(mtr_memo_contains(mtr, buf_block_align(page), MTR_MEMO_PAGE_X_FIX)); /* The page gets invalid for optimistic searches: increment the frame modify clock */ buf_frame_modify_clock_inc(page); if (tree->type & DICT_IBUF) { btr_page_free_for_ibuf(tree, page, mtr); return; } root = btr_root_get(tree, mtr); if (level == 0) { seg_header = root + PAGE_HEADER + PAGE_BTR_SEG_LEAF; } else { seg_header = root + PAGE_HEADER + PAGE_BTR_SEG_TOP; } space = buf_frame_get_space_id(page); page_no = buf_frame_get_page_no(page); fseg_free_page(seg_header, space, page_no, mtr); } /****************************************************************** Frees a file page used in an index tree. NOTE: cannot free field external storage pages because the page must contain info on its level. */ void btr_page_free( /*==========*/ dict_tree_t* tree, /* in: index tree */ page_t* page, /* in: page to be freed, x-latched */ mtr_t* mtr) /* in: mtr */ { ulint level; ut_ad(mtr_memo_contains(mtr, buf_block_align(page), MTR_MEMO_PAGE_X_FIX)); level = btr_page_get_level(page, mtr); btr_page_free_low(tree, page, level, mtr); } /****************************************************************** Sets the child node file address in a node pointer. */ UNIV_INLINE void btr_node_ptr_set_child_page_no( /*===========================*/ rec_t* rec, /* in: node pointer record */ ulint page_no, /* in: child node address */ mtr_t* mtr) /* in: mtr */ { ulint n_fields; byte* field; ulint len; ut_ad(0 < btr_page_get_level(buf_frame_align(rec), mtr)); n_fields = rec_get_n_fields(rec); /* The child address is in the last field */ field = rec_get_nth_field(rec, n_fields - 1, &len); ut_ad(len == 4); mlog_write_ulint(field, page_no, MLOG_4BYTES, mtr); } /**************************************************************** Returns the child page of a node pointer and x-latches it. */ static page_t* btr_node_ptr_get_child( /*===================*/ /* out: child page, x-latched */ rec_t* node_ptr, /* in: node pointer */ mtr_t* mtr) /* in: mtr */ { ulint page_no; ulint space; page_t* page; space = buf_frame_get_space_id(node_ptr); page_no = btr_node_ptr_get_child_page_no(node_ptr); page = btr_page_get(space, page_no, RW_X_LATCH, mtr); return(page); } /**************************************************************** Returns the upper level node pointer to a page. It is assumed that mtr holds an x-latch on the tree. */ static rec_t* btr_page_get_father_for_rec( /*========================*/ /* out: pointer to node pointer record, its page x-latched */ dict_tree_t* tree, /* in: index tree */ page_t* page, /* in: page: must contain at least one user record */ rec_t* user_rec,/* in: user_record on page */ mtr_t* mtr) /* in: mtr */ { mem_heap_t* heap; dtuple_t* tuple; btr_cur_t cursor; rec_t* node_ptr; ut_ad(mtr_memo_contains(mtr, dict_tree_get_lock(tree), MTR_MEMO_X_LOCK)); ut_a(user_rec != page_get_supremum_rec(page)); ut_a(user_rec != page_get_infimum_rec(page)); ut_ad(dict_tree_get_page(tree) != buf_frame_get_page_no(page)); heap = mem_heap_create(100); tuple = dict_tree_build_node_ptr(tree, user_rec, 0, heap, btr_page_get_level(page, mtr)); /* In the following, we choose just any index from the tree as the first parameter for btr_cur_search_to_nth_level. */ btr_cur_search_to_nth_level(UT_LIST_GET_FIRST(tree->tree_indexes), btr_page_get_level(page, mtr) + 1, tuple, PAGE_CUR_LE, BTR_CONT_MODIFY_TREE, &cursor, 0, mtr); node_ptr = btr_cur_get_rec(&cursor); ut_a(btr_node_ptr_get_child_page_no(node_ptr) == buf_frame_get_page_no(page)); mem_heap_free(heap); return(node_ptr); } /**************************************************************** Returns the upper level node pointer to a page. It is assumed that mtr holds an x-latch on the tree. */ static rec_t* btr_page_get_father_node_ptr( /*=========================*/ /* out: pointer to node pointer record */ dict_tree_t* tree, /* in: index tree */ page_t* page, /* in: page: must contain at least one user record */ mtr_t* mtr) /* in: mtr */ { return(btr_page_get_father_for_rec(tree, page, page_rec_get_next(page_get_infimum_rec(page)), mtr)); } /**************************************************************** Creates the root node for a new index tree. */ ulint btr_create( /*=======*/ /* out: page number of the created root, FIL_NULL if did not succeed */ ulint type, /* in: type of the index */ ulint space, /* in: space where created */ dulint index_id,/* in: index id */ mtr_t* mtr) /* in: mini-transaction handle */ { ulint page_no; buf_frame_t* ibuf_hdr_frame; buf_frame_t* frame; page_t* page; /* Create the two new segments (one, in the case of an ibuf tree) for the index tree; the segment headers are put on the allocated root page (for an ibuf tree, not in the root, but on a separate ibuf header page) */ if (type & DICT_IBUF) { /* Allocate first the ibuf header page */ ibuf_hdr_frame = fseg_create(space, 0, IBUF_HEADER + IBUF_TREE_SEG_HEADER, mtr); buf_page_dbg_add_level(ibuf_hdr_frame, SYNC_TREE_NODE_NEW); ut_ad(buf_frame_get_page_no(ibuf_hdr_frame) == IBUF_HEADER_PAGE_NO); /* Allocate then the next page to the segment: it will be the tree root page */ page_no = fseg_alloc_free_page( ibuf_hdr_frame + IBUF_HEADER + IBUF_TREE_SEG_HEADER, IBUF_TREE_ROOT_PAGE_NO, FSP_UP, mtr); ut_ad(page_no == IBUF_TREE_ROOT_PAGE_NO); frame = buf_page_get(space, page_no, RW_X_LATCH, mtr); } else { frame = fseg_create(space, 0, PAGE_HEADER + PAGE_BTR_SEG_TOP, mtr); } if (frame == NULL) { return(FIL_NULL); } page_no = buf_frame_get_page_no(frame); buf_page_dbg_add_level(frame, SYNC_TREE_NODE_NEW); if (type & DICT_IBUF) { /* It is an insert buffer tree: initialize the free list */ ut_ad(page_no == IBUF_TREE_ROOT_PAGE_NO); flst_init(frame + PAGE_HEADER + PAGE_BTR_IBUF_FREE_LIST, mtr); } else { /* It is a non-ibuf tree: create a file segment for leaf pages */ fseg_create(space, page_no, PAGE_HEADER + PAGE_BTR_SEG_LEAF, mtr); /* The fseg create acquires a second latch on the page, therefore we must declare it: */ buf_page_dbg_add_level(frame, SYNC_TREE_NODE_NEW); } /* Create a new index page on the the allocated segment page */ page = page_create(frame, mtr); /* Set the index id of the page */ btr_page_set_index_id(page, index_id, mtr); /* Set the level of the new index page */ btr_page_set_level(page, 0, mtr); /* Set the next node and previous node fields */ btr_page_set_next(page, FIL_NULL, mtr); btr_page_set_prev(page, FIL_NULL, mtr); /* We reset the free bits for the page to allow creation of several trees in the same mtr, otherwise the latch on a bitmap page would prevent it because of the latching order */ ibuf_reset_free_bits_with_type(type, page); /* In the following assertion we test that two records of maximum allowed size fit on the root page: this fact is needed to ensure correctness of split algorithms */ ut_ad(page_get_max_insert_size(page, 2) > 2 * BTR_PAGE_MAX_REC_SIZE); return(page_no); } /**************************************************************** Frees a B-tree except the root page, which MUST be freed after this by calling btr_free_root. */ void btr_free_but_not_root( /*==================*/ ulint space, /* in: space where created */ ulint root_page_no) /* in: root page number */ { ibool finished; page_t* root; mtr_t mtr; leaf_loop: mtr_start(&mtr); root = btr_page_get(space, root_page_no, RW_X_LATCH, &mtr); /* NOTE: page hash indexes are dropped when a page is freed inside fsp0fsp. */ finished = fseg_free_step( root + PAGE_HEADER + PAGE_BTR_SEG_LEAF, &mtr); mtr_commit(&mtr); if (!finished) { goto leaf_loop; } top_loop: mtr_start(&mtr); root = btr_page_get(space, root_page_no, RW_X_LATCH, &mtr); finished = fseg_free_step_not_header( root + PAGE_HEADER + PAGE_BTR_SEG_TOP, &mtr); mtr_commit(&mtr); if (!finished) { goto top_loop; } } /**************************************************************** Frees the B-tree root page. Other tree MUST already have been freed. */ void btr_free_root( /*==========*/ ulint space, /* in: space where created */ ulint root_page_no, /* in: root page number */ mtr_t* mtr) /* in: a mini-transaction which has already been started */ { ibool finished; page_t* root; root = btr_page_get(space, root_page_no, RW_X_LATCH, mtr); btr_search_drop_page_hash_index(root); top_loop: finished = fseg_free_step( root + PAGE_HEADER + PAGE_BTR_SEG_TOP, mtr); if (!finished) { goto top_loop; } } /***************************************************************** Reorganizes an index page. */ void btr_page_reorganize_low( /*====================*/ ibool low, /* in: TRUE if locks should not be updated, i.e., there cannot exist locks on the page */ page_t* page, /* in: page to be reorganized */ mtr_t* mtr) /* in: mtr */ { page_t* new_page; ulint log_mode; ut_ad(mtr_memo_contains(mtr, buf_block_align(page), MTR_MEMO_PAGE_X_FIX)); /* Write the log record */ mlog_write_initial_log_record(page, MLOG_PAGE_REORGANIZE, mtr); /* Turn logging off */ log_mode = mtr_set_log_mode(mtr, MTR_LOG_NONE); new_page = buf_frame_alloc(); /* Copy the old page to temporary space */ buf_frame_copy(new_page, page); btr_search_drop_page_hash_index(page); /* Recreate the page: note that global data on page (possible segment headers, next page-field, etc.) is preserved intact */ page_create(page, mtr); /* Copy the records from the temporary space to the recreated page; do not copy the lock bits yet */ page_copy_rec_list_end_no_locks(page, new_page, page_get_infimum_rec(new_page), mtr); /* Copy max trx id to recreated page */ page_set_max_trx_id(page, page_get_max_trx_id(new_page)); if (!low) { /* Update the record lock bitmaps */ lock_move_reorganize_page(page, new_page); } buf_frame_free(new_page); /* Restore logging mode */ mtr_set_log_mode(mtr, log_mode); } /***************************************************************** Reorganizes an index page. */ void btr_page_reorganize( /*================*/ page_t* page, /* in: page to be reorganized */ mtr_t* mtr) /* in: mtr */ { btr_page_reorganize_low(FALSE, page, mtr); } /*************************************************************** Parses a redo log record of reorganizing a page. */ byte* btr_parse_page_reorganize( /*======================*/ /* out: end of log record or NULL */ byte* ptr, /* in: buffer */ byte* end_ptr __attribute__((unused)), /* in: buffer end */ page_t* page, /* in: page or NULL */ mtr_t* mtr) /* in: mtr or NULL */ { ut_ad(ptr && end_ptr); /* The record is empty, except for the record initial part */ if (page) { btr_page_reorganize_low(TRUE, page, mtr); } return(ptr); } /***************************************************************** Empties an index page. */ static void btr_page_empty( /*===========*/ page_t* page, /* in: page to be emptied */ mtr_t* mtr) /* in: mtr */ { ut_ad(mtr_memo_contains(mtr, buf_block_align(page), MTR_MEMO_PAGE_X_FIX)); btr_search_drop_page_hash_index(page); /* Recreate the page: note that global data on page (possible segment headers, next page-field, etc.) is preserved intact */ page_create(page, mtr); } /***************************************************************** Makes tree one level higher by splitting the root, and inserts the tuple. It is assumed that mtr contains an x-latch on the tree. NOTE that the operation of this function must always succeed, we cannot reverse it: therefore enough free disk space must be guaranteed to be available before this function is called. */ rec_t* btr_root_raise_and_insert( /*======================*/ /* out: inserted record */ btr_cur_t* cursor, /* in: cursor at which to insert: must be on the root page; when the function returns, the cursor is positioned on the predecessor of the inserted record */ dtuple_t* tuple, /* in: tuple to insert */ mtr_t* mtr) /* in: mtr */ { dict_tree_t* tree; page_t* root; page_t* new_page; ulint new_page_no; rec_t* rec; mem_heap_t* heap; dtuple_t* node_ptr; ulint level; rec_t* node_ptr_rec; page_cur_t* page_cursor; root = btr_cur_get_page(cursor); tree = btr_cur_get_tree(cursor); ut_ad(dict_tree_get_page(tree) == buf_frame_get_page_no(root)); ut_ad(mtr_memo_contains(mtr, dict_tree_get_lock(tree), MTR_MEMO_X_LOCK)); ut_ad(mtr_memo_contains(mtr, buf_block_align(root), MTR_MEMO_PAGE_X_FIX)); btr_search_drop_page_hash_index(root); /* Allocate a new page to the tree. Root splitting is done by first moving the root records to the new page, emptying the root, putting a node pointer to the new page, and then splitting the new page. */ new_page = btr_page_alloc(tree, 0, FSP_NO_DIR, btr_page_get_level(root, mtr), mtr); btr_page_create(new_page, tree, mtr); level = btr_page_get_level(root, mtr); /* Set the levels of the new index page and root page */ btr_page_set_level(new_page, level, mtr); btr_page_set_level(root, level + 1, mtr); /* Set the next node and previous node fields of new page */ btr_page_set_next(new_page, FIL_NULL, mtr); btr_page_set_prev(new_page, FIL_NULL, mtr); /* Move the records from root to the new page */ page_move_rec_list_end(new_page, root, page_get_infimum_rec(root), mtr); /* If this is a pessimistic insert which is actually done to perform a pessimistic update then we have stored the lock information of the record to be inserted on the infimum of the root page: we cannot discard the lock structs on the root page */ lock_update_root_raise(new_page, root); /* Create a memory heap where the node pointer is stored */ heap = mem_heap_create(100); rec = page_rec_get_next(page_get_infimum_rec(new_page)); new_page_no = buf_frame_get_page_no(new_page); /* Build the node pointer (= node key and page address) for the child */ node_ptr = dict_tree_build_node_ptr(tree, rec, new_page_no, heap, level); /* Reorganize the root to get free space */ btr_page_reorganize(root, mtr); page_cursor = btr_cur_get_page_cur(cursor); /* Insert node pointer to the root */ page_cur_set_before_first(root, page_cursor); node_ptr_rec = page_cur_tuple_insert(page_cursor, node_ptr, mtr); ut_ad(node_ptr_rec); /* The node pointer must be marked as the predefined minimum record, as there is no lower alphabetical limit to records in the leftmost node of a level: */ btr_set_min_rec_mark(node_ptr_rec, mtr); /* Free the memory heap */ mem_heap_free(heap); /* We play safe and reset the free bits for the new page */ /* printf("Root raise new page no %lu\n", buf_frame_get_page_no(new_page)); */ ibuf_reset_free_bits(UT_LIST_GET_FIRST(tree->tree_indexes), new_page); /* Reposition the cursor to the child node */ page_cur_search(new_page, tuple, PAGE_CUR_LE, page_cursor); /* Split the child and insert tuple */ return(btr_page_split_and_insert(cursor, tuple, mtr)); } /***************************************************************** Decides if the page should be split at the convergence point of inserts converging to the left. */ ibool btr_page_get_split_rec_to_left( /*===========================*/ /* out: TRUE if split recommended */ btr_cur_t* cursor, /* in: cursor at which to insert */ rec_t** split_rec) /* out: if split recommended, the first record on upper half page, or NULL if tuple to be inserted should be first */ { page_t* page; rec_t* insert_point; rec_t* infimum; page = btr_cur_get_page(cursor); insert_point = btr_cur_get_rec(cursor); if ((page_header_get_ptr(page, PAGE_LAST_INSERT) == page_rec_get_next(insert_point)) && (page_header_get_field(page, PAGE_DIRECTION) == PAGE_LEFT) && ((page_header_get_field(page, PAGE_N_DIRECTION) >= BTR_PAGE_SEQ_INSERT_LIMIT) || (page_header_get_field(page, PAGE_N_DIRECTION) + 1 >= page_get_n_recs(page)))) { infimum = page_get_infimum_rec(page); if ((infimum != insert_point) && (page_rec_get_next(infimum) != insert_point)) { *split_rec = insert_point; } else { *split_rec = page_rec_get_next(insert_point); } return(TRUE); } return(FALSE); } /***************************************************************** Decides if the page should be split at the convergence point of inserts converging to the right. */ ibool btr_page_get_split_rec_to_right( /*============================*/ /* out: TRUE if split recommended */ btr_cur_t* cursor, /* in: cursor at which to insert */ rec_t** split_rec) /* out: if split recommended, the first record on upper half page, or NULL if tuple to be inserted should be first */ { page_t* page; rec_t* insert_point; rec_t* supremum; page = btr_cur_get_page(cursor); insert_point = btr_cur_get_rec(cursor); if ((page_header_get_ptr(page, PAGE_LAST_INSERT) == insert_point) && (page_header_get_field(page, PAGE_DIRECTION) == PAGE_RIGHT) && ((page_header_get_field(page, PAGE_N_DIRECTION) >= BTR_PAGE_SEQ_INSERT_LIMIT) || (page_header_get_field(page, PAGE_N_DIRECTION) + 1 >= page_get_n_recs(page)))) { supremum = page_get_supremum_rec(page); if ((page_rec_get_next(insert_point) != supremum) && (page_rec_get_next(page_rec_get_next(insert_point)) != supremum) && (page_rec_get_next(page_rec_get_next( page_rec_get_next(insert_point))) != supremum)) { /* If there are >= 3 user records up from the insert point, split all but 2 off */ *split_rec = page_rec_get_next(page_rec_get_next( page_rec_get_next(insert_point))); } else { /* Else split at inserted record */ *split_rec = NULL; } return(TRUE); } return(FALSE); } /***************************************************************** Calculates a split record such that the tuple will certainly fit on its half-page when the split is performed. We assume in this function only that the cursor page has at least one user record. */ static rec_t* btr_page_get_sure_split_rec( /*========================*/ /* out: split record, or NULL if tuple will be the first record on upper half-page */ btr_cur_t* cursor, /* in: cursor at which insert should be made */ dtuple_t* tuple) /* in: tuple to insert */ { page_t* page; ulint insert_size; ulint free_space; ulint total_data; ulint total_n_recs; ulint total_space; ulint incl_data; rec_t* ins_rec; rec_t* rec; rec_t* next_rec; ulint n; page = btr_cur_get_page(cursor); insert_size = rec_get_converted_size(tuple); free_space = page_get_free_space_of_empty(); /* free_space is now the free space of a created new page */ total_data = page_get_data_size(page) + insert_size; total_n_recs = page_get_n_recs(page) + 1; ut_ad(total_n_recs >= 2); total_space = total_data + page_dir_calc_reserved_space(total_n_recs); n = 0; incl_data = 0; ins_rec = btr_cur_get_rec(cursor); rec = page_get_infimum_rec(page); /* We start to include records to the left half, and when the space reserved by them exceeds half of total_space, then if the included records fit on the left page, they will be put there if something was left over also for the right page, otherwise the last included record will be the first on the right half page */ for (;;) { /* Decide the next record to include */ if (rec == ins_rec) { rec = NULL; /* NULL denotes that tuple is now included */ } else if (rec == NULL) { rec = page_rec_get_next(ins_rec); } else { rec = page_rec_get_next(rec); } if (rec == NULL) { /* Include tuple */ incl_data += insert_size; } else { incl_data += rec_get_size(rec); } n++; if (incl_data + page_dir_calc_reserved_space(n) >= total_space / 2) { if (incl_data + page_dir_calc_reserved_space(n) <= free_space) { /* The next record will be the first on the right half page if it is not the supremum record of page */ if (rec == ins_rec) { next_rec = NULL; } else if (rec == NULL) { next_rec = page_rec_get_next(ins_rec); } else { next_rec = page_rec_get_next(rec); } if (next_rec != page_get_supremum_rec(page)) { return(next_rec); } } return(rec); } } } /***************************************************************** Returns TRUE if the insert fits on the appropriate half-page with the chosen split_rec. */ static ibool btr_page_insert_fits( /*=================*/ /* out: TRUE if fits */ btr_cur_t* cursor, /* in: cursor at which insert should be made */ rec_t* split_rec, /* in: suggestion for first record on upper half-page, or NULL if tuple to be inserted should be first */ dtuple_t* tuple) /* in: tuple to insert */ { page_t* page; ulint insert_size; ulint free_space; ulint total_data; ulint total_n_recs; rec_t* rec; rec_t* end_rec; page = btr_cur_get_page(cursor); insert_size = rec_get_converted_size(tuple); free_space = page_get_free_space_of_empty(); /* free_space is now the free space of a created new page */ total_data = page_get_data_size(page) + insert_size; total_n_recs = page_get_n_recs(page) + 1; /* We determine which records (from rec to end_rec, not including end_rec) will end up on the other half page from tuple when it is inserted. */ if (split_rec == NULL) { rec = page_rec_get_next(page_get_infimum_rec(page)); end_rec = page_rec_get_next(btr_cur_get_rec(cursor)); } else if (cmp_dtuple_rec(tuple, split_rec) >= 0) { rec = page_rec_get_next(page_get_infimum_rec(page)); end_rec = split_rec; } else { rec = split_rec; end_rec = page_get_supremum_rec(page); } if (total_data + page_dir_calc_reserved_space(total_n_recs) <= free_space) { /* Ok, there will be enough available space on the half page where the tuple is inserted */ return(TRUE); } while (rec != end_rec) { /* In this loop we calculate the amount of reserved space after rec is removed from page. */ total_data -= rec_get_size(rec); total_n_recs--; if (total_data + page_dir_calc_reserved_space(total_n_recs) <= free_space) { /* Ok, there will be enough available space on the half page where the tuple is inserted */ return(TRUE); } rec = page_rec_get_next(rec); } return(FALSE); } /*********************************************************** Inserts a data tuple to a tree on a non-leaf level. It is assumed that mtr holds an x-latch on the tree. */ void btr_insert_on_non_leaf_level( /*=========================*/ dict_tree_t* tree, /* in: tree */ ulint level, /* in: level, must be > 0 */ dtuple_t* tuple, /* in: the record to be inserted */ mtr_t* mtr) /* in: mtr */ { big_rec_t* dummy_big_rec; btr_cur_t cursor; ulint err; rec_t* rec; ut_ad(level > 0); /* In the following, choose just any index from the tree as the first parameter for btr_cur_search_to_nth_level. */ btr_cur_search_to_nth_level(UT_LIST_GET_FIRST(tree->tree_indexes), level, tuple, PAGE_CUR_LE, BTR_CONT_MODIFY_TREE, &cursor, 0, mtr); err = btr_cur_pessimistic_insert(BTR_NO_LOCKING_FLAG | BTR_KEEP_SYS_FLAG | BTR_NO_UNDO_LOG_FLAG, &cursor, tuple, &rec, &dummy_big_rec, NULL, mtr); ut_a(err == DB_SUCCESS); } /****************************************************************** Attaches the halves of an index page on the appropriate level in an index tree. */ static void btr_attach_half_pages( /*==================*/ dict_tree_t* tree, /* in: the index tree */ page_t* page, /* in: page to be split */ rec_t* split_rec, /* in: first record on upper half page */ page_t* new_page, /* in: the new half page */ ulint direction, /* in: FSP_UP or FSP_DOWN */ mtr_t* mtr) /* in: mtr */ { ulint space; rec_t* node_ptr; page_t* prev_page; page_t* next_page; ulint prev_page_no; ulint next_page_no; ulint level; page_t* lower_page; page_t* upper_page; ulint lower_page_no; ulint upper_page_no; dtuple_t* node_ptr_upper; mem_heap_t* heap; ut_ad(mtr_memo_contains(mtr, buf_block_align(page), MTR_MEMO_PAGE_X_FIX)); ut_ad(mtr_memo_contains(mtr, buf_block_align(new_page), MTR_MEMO_PAGE_X_FIX)); /* Based on split direction, decide upper and lower pages */ if (direction == FSP_DOWN) { lower_page_no = buf_frame_get_page_no(new_page); upper_page_no = buf_frame_get_page_no(page); lower_page = new_page; upper_page = page; /* Look from the tree for the node pointer to page */ node_ptr = btr_page_get_father_node_ptr(tree, page, mtr); /* Replace the address of the old child node (= page) with the address of the new lower half */ btr_node_ptr_set_child_page_no(node_ptr, lower_page_no, mtr); } else { lower_page_no = buf_frame_get_page_no(page); upper_page_no = buf_frame_get_page_no(new_page); lower_page = page; upper_page = new_page; } /* Create a memory heap where the data tuple is stored */ heap = mem_heap_create(100); /* Get the level of the split pages */ level = btr_page_get_level(page, mtr); /* Build the node pointer (= node key and page address) for the upper half */ node_ptr_upper = dict_tree_build_node_ptr(tree, split_rec, upper_page_no, heap, level); /* Insert it next to the pointer to the lower half. Note that this may generate recursion leading to a split on the higher level. */ btr_insert_on_non_leaf_level(tree, level + 1, node_ptr_upper, mtr); /* Free the memory heap */ mem_heap_free(heap); /* Get the previous and next pages of page */ prev_page_no = btr_page_get_prev(page, mtr); next_page_no = btr_page_get_next(page, mtr); space = buf_frame_get_space_id(page); /* Update page links of the level */ if (prev_page_no != FIL_NULL) { prev_page = btr_page_get(space, prev_page_no, RW_X_LATCH, mtr); btr_page_set_next(prev_page, lower_page_no, mtr); } if (next_page_no != FIL_NULL) { next_page = btr_page_get(space, next_page_no, RW_X_LATCH, mtr); btr_page_set_prev(next_page, upper_page_no, mtr); } btr_page_set_prev(lower_page, prev_page_no, mtr); btr_page_set_next(lower_page, upper_page_no, mtr); btr_page_set_level(lower_page, level, mtr); btr_page_set_prev(upper_page, lower_page_no, mtr); btr_page_set_next(upper_page, next_page_no, mtr); btr_page_set_level(upper_page, level, mtr); } /***************************************************************** Splits an index page to halves and inserts the tuple. It is assumed that mtr holds an x-latch to the index tree. NOTE: the tree x-latch is released within this function! NOTE that the operation of this function must always succeed, we cannot reverse it: therefore enough free disk space must be guaranteed to be available before this function is called. */ rec_t* btr_page_split_and_insert( /*======================*/ /* out: inserted record; NOTE: the tree x-latch is released! NOTE: 2 free disk pages must be available! */ btr_cur_t* cursor, /* in: cursor at which to insert; when the function returns, the cursor is positioned on the predecessor of the inserted record */ dtuple_t* tuple, /* in: tuple to insert */ mtr_t* mtr) /* in: mtr */ { dict_tree_t* tree; page_t* page; ulint page_no; byte direction; ulint hint_page_no; page_t* new_page; rec_t* split_rec; page_t* left_page; page_t* right_page; page_t* insert_page; page_cur_t* page_cursor; rec_t* first_rec; byte* buf = 0; /* remove warning */ rec_t* move_limit; ibool insert_will_fit; ulint n_iterations = 0; rec_t* rec; func_start: tree = btr_cur_get_tree(cursor); ut_ad(mtr_memo_contains(mtr, dict_tree_get_lock(tree), MTR_MEMO_X_LOCK)); ut_ad(rw_lock_own(dict_tree_get_lock(tree), RW_LOCK_EX)); page = btr_cur_get_page(cursor); ut_ad(mtr_memo_contains(mtr, buf_block_align(page), MTR_MEMO_PAGE_X_FIX)); ut_ad(page_get_n_recs(page) >= 2); page_no = buf_frame_get_page_no(page); /* 1. Decide the split record; split_rec == NULL means that the tuple to be inserted should be the first record on the upper half-page */ if (n_iterations > 0) { direction = FSP_UP; hint_page_no = page_no + 1; split_rec = btr_page_get_sure_split_rec(cursor, tuple); } else if (btr_page_get_split_rec_to_right(cursor, &split_rec)) { direction = FSP_UP; hint_page_no = page_no + 1; } else if (btr_page_get_split_rec_to_left(cursor, &split_rec)) { direction = FSP_DOWN; hint_page_no = page_no - 1; } else { direction = FSP_UP; hint_page_no = page_no + 1; split_rec = page_get_middle_rec(page); } /* 2. Allocate a new page to the tree */ new_page = btr_page_alloc(tree, hint_page_no, direction, btr_page_get_level(page, mtr), mtr); btr_page_create(new_page, tree, mtr); /* 3. Calculate the first record on the upper half-page, and the first record (move_limit) on original page which ends up on the upper half */ if (split_rec != NULL) { first_rec = split_rec; move_limit = split_rec; } else { buf = mem_alloc(rec_get_converted_size(tuple)); first_rec = rec_convert_dtuple_to_rec(buf, tuple); move_limit = page_rec_get_next(btr_cur_get_rec(cursor)); } /* 4. Do first the modifications in the tree structure */ btr_attach_half_pages(tree, page, first_rec, new_page, direction, mtr); if (split_rec == NULL) { mem_free(buf); } /* If the split is made on the leaf level and the insert will fit on the appropriate half-page, we may release the tree x-latch. We can then move the records after releasing the tree latch, thus reducing the tree latch contention. */ insert_will_fit = btr_page_insert_fits(cursor, split_rec, tuple); if (insert_will_fit && (btr_page_get_level(page, mtr) == 0)) { mtr_memo_release(mtr, dict_tree_get_lock(tree), MTR_MEMO_X_LOCK); } /* 5. Move then the records to the new page */ if (direction == FSP_DOWN) { /* printf("Split left\n"); */ page_move_rec_list_start(new_page, page, move_limit, mtr); left_page = new_page; right_page = page; lock_update_split_left(right_page, left_page); } else { /* printf("Split right\n"); */ page_move_rec_list_end(new_page, page, move_limit, mtr); left_page = page; right_page = new_page; lock_update_split_right(right_page, left_page); } /* 6. The split and the tree modification is now completed. Decide the page where the tuple should be inserted */ if (split_rec == NULL) { insert_page = right_page; } else if (cmp_dtuple_rec(tuple, first_rec) >= 0) { insert_page = right_page; } else { insert_page = left_page; } /* 7. Reposition the cursor for insert and try insertion */ page_cursor = btr_cur_get_page_cur(cursor); page_cur_search(insert_page, tuple, PAGE_CUR_LE, page_cursor); rec = page_cur_tuple_insert(page_cursor, tuple, mtr); if (rec != NULL) { /* Insert fit on the page: update the free bits for the left and right pages in the same mtr */ ibuf_update_free_bits_for_two_pages_low(cursor->index, left_page, right_page, mtr); /* printf("Split and insert done %lu %lu\n", buf_frame_get_page_no(left_page), buf_frame_get_page_no(right_page)); */ return(rec); } /* 8. If insert did not fit, try page reorganization */ btr_page_reorganize(insert_page, mtr); page_cur_search(insert_page, tuple, PAGE_CUR_LE, page_cursor); rec = page_cur_tuple_insert(page_cursor, tuple, mtr); if (rec == NULL) { /* The insert did not fit on the page: loop back to the start of the function for a new split */ /* We play safe and reset the free bits for new_page */ ibuf_reset_free_bits(cursor->index, new_page); /* printf("Split second round %lu\n", buf_frame_get_page_no(page)); */ n_iterations++; ut_ad(n_iterations < 2); ut_ad(!insert_will_fit); goto func_start; } /* Insert fit on the page: update the free bits for the left and right pages in the same mtr */ ibuf_update_free_bits_for_two_pages_low(cursor->index, left_page, right_page, mtr); /* printf("Split and insert done %lu %lu\n", buf_frame_get_page_no(left_page), buf_frame_get_page_no(right_page)); */ ut_ad(page_validate(left_page, UT_LIST_GET_FIRST(tree->tree_indexes))); ut_ad(page_validate(right_page, UT_LIST_GET_FIRST(tree->tree_indexes))); return(rec); } /***************************************************************** Removes a page from the level list of pages. */ static void btr_level_list_remove( /*==================*/ dict_tree_t* tree __attribute__((unused)), /* in: index tree */ page_t* page, /* in: page to remove */ mtr_t* mtr) /* in: mtr */ { ulint space; ulint prev_page_no; page_t* prev_page; ulint next_page_no; page_t* next_page; ut_ad(tree && page && mtr); ut_ad(mtr_memo_contains(mtr, buf_block_align(page), MTR_MEMO_PAGE_X_FIX)); /* Get the previous and next page numbers of page */ prev_page_no = btr_page_get_prev(page, mtr); next_page_no = btr_page_get_next(page, mtr); space = buf_frame_get_space_id(page); /* Update page links of the level */ if (prev_page_no != FIL_NULL) { prev_page = btr_page_get(space, prev_page_no, RW_X_LATCH, mtr); btr_page_set_next(prev_page, next_page_no, mtr); } if (next_page_no != FIL_NULL) { next_page = btr_page_get(space, next_page_no, RW_X_LATCH, mtr); btr_page_set_prev(next_page, prev_page_no, mtr); } } /******************************************************************** Writes the redo log record for setting an index record as the predefined minimum record. */ UNIV_INLINE void btr_set_min_rec_mark_log( /*=====================*/ rec_t* rec, /* in: record */ mtr_t* mtr) /* in: mtr */ { mlog_write_initial_log_record(rec, MLOG_REC_MIN_MARK, mtr); /* Write rec offset as a 2-byte ulint */ mlog_catenate_ulint(mtr, rec - buf_frame_align(rec), MLOG_2BYTES); } /******************************************************************** Parses the redo log record for setting an index record as the predefined minimum record. */ byte* btr_parse_set_min_rec_mark( /*=======================*/ /* out: end of log record or NULL */ byte* ptr, /* in: buffer */ byte* end_ptr,/* in: buffer end */ page_t* page, /* in: page or NULL */ mtr_t* mtr) /* in: mtr or NULL */ { rec_t* rec; if (end_ptr < ptr + 2) { return(NULL); } if (page) { rec = page + mach_read_from_2(ptr); btr_set_min_rec_mark(rec, mtr); } return(ptr + 2); } /******************************************************************** Sets a record as the predefined minimum record. */ void btr_set_min_rec_mark( /*=================*/ rec_t* rec, /* in: record */ mtr_t* mtr) /* in: mtr */ { ulint info_bits; info_bits = rec_get_info_bits(rec); rec_set_info_bits(rec, info_bits | REC_INFO_MIN_REC_FLAG); btr_set_min_rec_mark_log(rec, mtr); } /***************************************************************** Deletes on the upper level the node pointer to a page. */ void btr_node_ptr_delete( /*================*/ dict_tree_t* tree, /* in: index tree */ page_t* page, /* in: page whose node pointer is deleted */ mtr_t* mtr) /* in: mtr */ { rec_t* node_ptr; btr_cur_t cursor; ibool compressed; ulint err; ut_ad(mtr_memo_contains(mtr, buf_block_align(page), MTR_MEMO_PAGE_X_FIX)); /* Delete node pointer on father page */ node_ptr = btr_page_get_father_node_ptr(tree, page, mtr); btr_cur_position(UT_LIST_GET_FIRST(tree->tree_indexes), node_ptr, &cursor); compressed = btr_cur_pessimistic_delete(&err, TRUE, &cursor, FALSE, mtr); ut_a(err == DB_SUCCESS); if (!compressed) { btr_cur_compress_if_useful(&cursor, mtr); } } /***************************************************************** If page is the only on its level, this function moves its records to the father page, thus reducing the tree height. */ static void btr_lift_page_up( /*=============*/ dict_tree_t* tree, /* in: index tree */ page_t* page, /* in: page which is the only on its level; must not be empty: use btr_discard_only_page_on_level if the last record from the page should be removed */ mtr_t* mtr) /* in: mtr */ { rec_t* node_ptr; page_t* father_page; ulint page_level; ut_ad(btr_page_get_prev(page, mtr) == FIL_NULL); ut_ad(btr_page_get_next(page, mtr) == FIL_NULL); ut_ad(mtr_memo_contains(mtr, buf_block_align(page), MTR_MEMO_PAGE_X_FIX)); node_ptr = btr_page_get_father_node_ptr(tree, page, mtr); father_page = buf_frame_align(node_ptr); page_level = btr_page_get_level(page, mtr); btr_search_drop_page_hash_index(page); /* Make the father empty */ btr_page_empty(father_page, mtr); /* Move records to the father */ page_copy_rec_list_end(father_page, page, page_get_infimum_rec(page), mtr); lock_update_copy_and_discard(father_page, page); btr_page_set_level(father_page, page_level, mtr); /* Free the file page */ btr_page_free(tree, page, mtr); /* We play safe and reset the free bits for the father */ ibuf_reset_free_bits(UT_LIST_GET_FIRST(tree->tree_indexes), father_page); ut_ad(page_validate(father_page, UT_LIST_GET_FIRST(tree->tree_indexes))); ut_ad(btr_check_node_ptr(tree, father_page, mtr)); } /***************************************************************** Tries to merge the page first to the left immediate brother if such a brother exists, and the node pointers to the current page and to the brother reside on the same page. If the left brother does not satisfy these conditions, looks at the right brother. If the page is the only one on that level lifts the records of the page to the father page, thus reducing the tree height. It is assumed that mtr holds an x-latch on the tree and on the page. If cursor is on the leaf level, mtr must also hold x-latches to the brothers, if they exist. NOTE: it is assumed that the caller has reserved enough free extents so that the compression will always succeed if done! */ void btr_compress( /*=========*/ btr_cur_t* cursor, /* in: cursor on the page to merge or lift; the page must not be empty: in record delete use btr_discard_page if the page would become empty */ mtr_t* mtr) /* in: mtr */ { dict_tree_t* tree; ulint space; ulint left_page_no; ulint right_page_no; page_t* merge_page; page_t* father_page; ibool is_left; page_t* page; rec_t* orig_pred; rec_t* orig_succ; rec_t* node_ptr; ulint data_size; ulint n_recs; ulint max_ins_size; ulint max_ins_size_reorg; ulint level; page = btr_cur_get_page(cursor); tree = btr_cur_get_tree(cursor); ut_ad(mtr_memo_contains(mtr, dict_tree_get_lock(tree), MTR_MEMO_X_LOCK)); ut_ad(mtr_memo_contains(mtr, buf_block_align(page), MTR_MEMO_PAGE_X_FIX)); level = btr_page_get_level(page, mtr); space = dict_tree_get_space(tree); left_page_no = btr_page_get_prev(page, mtr); right_page_no = btr_page_get_next(page, mtr); /* printf("Merge left page %lu right %lu \n", left_page_no, right_page_no); */ node_ptr = btr_page_get_father_node_ptr(tree, page, mtr); father_page = buf_frame_align(node_ptr); /* Decide the page to which we try to merge and which will inherit the locks */ if (left_page_no != FIL_NULL) { is_left = TRUE; merge_page = btr_page_get(space, left_page_no, RW_X_LATCH, mtr); } else if (right_page_no != FIL_NULL) { is_left = FALSE; merge_page = btr_page_get(space, right_page_no, RW_X_LATCH, mtr); } else { /* The page is the only one on the level, lift the records to the father */ btr_lift_page_up(tree, page, mtr); return; } n_recs = page_get_n_recs(page); data_size = page_get_data_size(page); max_ins_size_reorg = page_get_max_insert_size_after_reorganize( merge_page, n_recs); if (data_size > max_ins_size_reorg) { /* No space for merge */ return; } ut_ad(page_validate(merge_page, cursor->index)); max_ins_size = page_get_max_insert_size(merge_page, n_recs); if (data_size > max_ins_size) { /* We have to reorganize merge_page */ btr_page_reorganize(merge_page, mtr); ut_ad(page_validate(merge_page, cursor->index)); ut_ad(page_get_max_insert_size(merge_page, n_recs) == max_ins_size_reorg); } btr_search_drop_page_hash_index(page); /* Remove the page from the level list */ btr_level_list_remove(tree, page, mtr); if (is_left) { btr_node_ptr_delete(tree, page, mtr); } else { /* Replace the address of the old child node (= page) with the address of the merge page to the right */ btr_node_ptr_set_child_page_no(node_ptr, right_page_no, mtr); btr_node_ptr_delete(tree, merge_page, mtr); } /* Move records to the merge page */ if (is_left) { orig_pred = page_rec_get_prev( page_get_supremum_rec(merge_page)); page_copy_rec_list_start(merge_page, page, page_get_supremum_rec(page), mtr); lock_update_merge_left(merge_page, orig_pred, page); } else { orig_succ = page_rec_get_next( page_get_infimum_rec(merge_page)); page_copy_rec_list_end(merge_page, page, page_get_infimum_rec(page), mtr); lock_update_merge_right(orig_succ, page); } /* We have added new records to merge_page: update its free bits */ ibuf_update_free_bits_if_full(cursor->index, merge_page, UNIV_PAGE_SIZE, ULINT_UNDEFINED); ut_ad(page_validate(merge_page, cursor->index)); /* Free the file page */ btr_page_free(tree, page, mtr); ut_ad(btr_check_node_ptr(tree, merge_page, mtr)); } /***************************************************************** Discards a page that is the only page on its level. */ static void btr_discard_only_page_on_level( /*===========================*/ dict_tree_t* tree, /* in: index tree */ page_t* page, /* in: page which is the only on its level */ mtr_t* mtr) /* in: mtr */ { rec_t* node_ptr; page_t* father_page; ulint page_level; ut_ad(btr_page_get_prev(page, mtr) == FIL_NULL); ut_ad(btr_page_get_next(page, mtr) == FIL_NULL); ut_ad(mtr_memo_contains(mtr, buf_block_align(page), MTR_MEMO_PAGE_X_FIX)); btr_search_drop_page_hash_index(page); node_ptr = btr_page_get_father_node_ptr(tree, page, mtr); father_page = buf_frame_align(node_ptr); page_level = btr_page_get_level(page, mtr); lock_update_discard(page_get_supremum_rec(father_page), page); btr_page_set_level(father_page, page_level, mtr); /* Free the file page */ btr_page_free(tree, page, mtr); if (buf_frame_get_page_no(father_page) == dict_tree_get_page(tree)) { /* The father is the root page */ btr_page_empty(father_page, mtr); /* We play safe and reset the free bits for the father */ ibuf_reset_free_bits(UT_LIST_GET_FIRST(tree->tree_indexes), father_page); } else { ut_ad(page_get_n_recs(father_page) == 1); btr_discard_only_page_on_level(tree, father_page, mtr); } } /***************************************************************** Discards a page from a B-tree. This is used to remove the last record from a B-tree page: the whole page must be removed at the same time. This cannot be used for the root page, which is allowed to be empty. */ void btr_discard_page( /*=============*/ btr_cur_t* cursor, /* in: cursor on the page to discard: not on the root page */ mtr_t* mtr) /* in: mtr */ { dict_tree_t* tree; ulint space; ulint left_page_no; ulint right_page_no; page_t* merge_page; ibool is_left; page_t* page; rec_t* node_ptr; page = btr_cur_get_page(cursor); tree = btr_cur_get_tree(cursor); ut_ad(dict_tree_get_page(tree) != buf_frame_get_page_no(page)); ut_ad(mtr_memo_contains(mtr, dict_tree_get_lock(tree), MTR_MEMO_X_LOCK)); ut_ad(mtr_memo_contains(mtr, buf_block_align(page), MTR_MEMO_PAGE_X_FIX)); space = dict_tree_get_space(tree); /* Decide the page which will inherit the locks */ left_page_no = btr_page_get_prev(page, mtr); right_page_no = btr_page_get_next(page, mtr); if (left_page_no != FIL_NULL) { is_left = TRUE; merge_page = btr_page_get(space, left_page_no, RW_X_LATCH, mtr); } else if (right_page_no != FIL_NULL) { is_left = FALSE; merge_page = btr_page_get(space, right_page_no, RW_X_LATCH, mtr); } else { btr_discard_only_page_on_level(tree, page, mtr); return; } btr_search_drop_page_hash_index(page); if ((left_page_no == FIL_NULL) && (btr_page_get_level(page, mtr) > 0)) { /* We have to mark the leftmost node pointer on the right side page as the predefined minimum record */ node_ptr = page_rec_get_next(page_get_infimum_rec(merge_page)); ut_ad(node_ptr != page_get_supremum_rec(merge_page)); btr_set_min_rec_mark(node_ptr, mtr); } btr_node_ptr_delete(tree, page, mtr); /* Remove the page from the level list */ btr_level_list_remove(tree, page, mtr); if (is_left) { lock_update_discard(page_get_supremum_rec(merge_page), page); } else { lock_update_discard(page_rec_get_next( page_get_infimum_rec(merge_page)), page); } /* Free the file page */ btr_page_free(tree, page, mtr); ut_ad(btr_check_node_ptr(tree, merge_page, mtr)); } /***************************************************************** Prints size info of a B-tree. */ void btr_print_size( /*===========*/ dict_tree_t* tree) /* in: index tree */ { page_t* root; fseg_header_t* seg; mtr_t mtr; if (tree->type & DICT_IBUF) { printf( "Sorry, cannot print info of an ibuf tree: use ibuf functions\n"); return; } mtr_start(&mtr); root = btr_root_get(tree, &mtr); seg = root + PAGE_HEADER + PAGE_BTR_SEG_TOP; printf("INFO OF THE NON-LEAF PAGE SEGMENT\n"); fseg_print(seg, &mtr); if (!(tree->type & DICT_UNIVERSAL)) { seg = root + PAGE_HEADER + PAGE_BTR_SEG_LEAF; printf("INFO OF THE LEAF PAGE SEGMENT\n"); fseg_print(seg, &mtr); } mtr_commit(&mtr); } /**************************************************************** Prints recursively index tree pages. */ static void btr_print_recursive( /*================*/ dict_tree_t* tree, /* in: index tree */ page_t* page, /* in: index page */ ulint width, /* in: print this many entries from start and end */ mtr_t* mtr) /* in: mtr */ { page_cur_t cursor; ulint n_recs; ulint i = 0; mtr_t mtr2; rec_t* node_ptr; page_t* child; ut_ad(mtr_memo_contains(mtr, buf_block_align(page), MTR_MEMO_PAGE_X_FIX)); printf("NODE ON LEVEL %lu page number %lu\n", btr_page_get_level(page, mtr), buf_frame_get_page_no(page)); page_print(page, width, width); n_recs = page_get_n_recs(page); page_cur_set_before_first(page, &cursor); page_cur_move_to_next(&cursor); while (!page_cur_is_after_last(&cursor)) { if (0 == btr_page_get_level(page, mtr)) { /* If this is the leaf level, do nothing */ } else if ((i <= width) || (i >= n_recs - width)) { mtr_start(&mtr2); node_ptr = page_cur_get_rec(&cursor); child = btr_node_ptr_get_child(node_ptr, &mtr2); btr_print_recursive(tree, child, width, &mtr2); mtr_commit(&mtr2); } page_cur_move_to_next(&cursor); i++; } } /****************************************************************** Prints directories and other info of all nodes in the tree. */ void btr_print_tree( /*===========*/ dict_tree_t* tree, /* in: tree */ ulint width) /* in: print this many entries from start and end */ { mtr_t mtr; page_t* root; printf("--------------------------\n"); printf("INDEX TREE PRINT\n"); mtr_start(&mtr); root = btr_root_get(tree, &mtr); btr_print_recursive(tree, root, width, &mtr); mtr_commit(&mtr); btr_validate_tree(tree); } /**************************************************************** Checks that the node pointer to a page is appropriate. */ ibool btr_check_node_ptr( /*===============*/ /* out: TRUE */ dict_tree_t* tree, /* in: index tree */ page_t* page, /* in: index page */ mtr_t* mtr) /* in: mtr */ { mem_heap_t* heap; rec_t* node_ptr; dtuple_t* node_ptr_tuple; ut_ad(mtr_memo_contains(mtr, buf_block_align(page), MTR_MEMO_PAGE_X_FIX)); if (dict_tree_get_page(tree) == buf_frame_get_page_no(page)) { return(TRUE); } node_ptr = btr_page_get_father_node_ptr(tree, page, mtr); if (btr_page_get_level(page, mtr) == 0) { return(TRUE); } heap = mem_heap_create(256); node_ptr_tuple = dict_tree_build_node_ptr( tree, page_rec_get_next(page_get_infimum_rec(page)), 0, heap, btr_page_get_level(page, mtr)); ut_a(cmp_dtuple_rec(node_ptr_tuple, node_ptr) == 0); mem_heap_free(heap); return(TRUE); } /**************************************************************** Checks the size and number of fields in a record based on the definition of the index. */ static ibool btr_index_rec_validate( /*====================*/ /* out: TRUE if ok */ rec_t* rec, /* in: index record */ dict_index_t* index) /* in: index */ { dtype_t* type; byte* data; ulint len; ulint n; ulint i; char err_buf[1000]; n = dict_index_get_n_fields(index); if (rec_get_n_fields(rec) != n) { fprintf(stderr, "Record has %lu fields, should have %lu\n", rec_get_n_fields(rec), n); rec_sprintf(err_buf, 900, rec); fprintf(stderr, "InnoDB: record %s\n", err_buf); return(FALSE); } for (i = 0; i < n; i++) { data = rec_get_nth_field(rec, i, &len); type = dict_index_get_nth_type(index, i); if (len != UNIV_SQL_NULL && dtype_is_fixed_size(type) && len != dtype_get_fixed_size(type)) { fprintf(stderr, "Record field %lu len is %lu, should be %lu\n", i, len, dtype_get_fixed_size(type)); rec_sprintf(err_buf, 900, rec); fprintf(stderr, "InnoDB: record %s\n", err_buf); return(FALSE); } } return(TRUE); } /**************************************************************** Checks the size and number of fields in records based on the definition of the index. */ static ibool btr_index_page_validate( /*====================*/ /* out: TRUE if ok */ page_t* page, /* in: index page */ dict_index_t* index) /* in: index */ { rec_t* rec; page_cur_t cur; ibool ret = TRUE; page_cur_set_before_first(page, &cur); page_cur_move_to_next(&cur); for (;;) { rec = (&cur)->rec; if (page_cur_is_after_last(&cur)) { break; } if (!btr_index_rec_validate(rec, index)) { ret = FALSE; } page_cur_move_to_next(&cur); } return(ret); } /**************************************************************** Validates index tree level. */ static ibool btr_validate_level( /*===============*/ /* out: TRUE if ok */ dict_tree_t* tree, /* in: index tree */ ulint level) /* in: level number */ { ulint space; page_t* page; page_t* right_page = 0; /* remove warning */ page_t* father_page; page_t* right_father_page; rec_t* node_ptr; rec_t* right_node_ptr; ulint right_page_no; ulint left_page_no; page_cur_t cursor; mem_heap_t* heap; dtuple_t* node_ptr_tuple; ibool ret = TRUE; dict_index_t* index; mtr_t mtr; char err_buf[1000]; mtr_start(&mtr); mtr_x_lock(dict_tree_get_lock(tree), &mtr); page = btr_root_get(tree, &mtr); space = buf_frame_get_space_id(page); while (level != btr_page_get_level(page, &mtr)) { ut_a(btr_page_get_level(page, &mtr) > 0); page_cur_set_before_first(page, &cursor); page_cur_move_to_next(&cursor); node_ptr = page_cur_get_rec(&cursor); page = btr_node_ptr_get_child(node_ptr, &mtr); } index = UT_LIST_GET_FIRST(tree->tree_indexes); /* Now we are on the desired level */ loop: mtr_x_lock(dict_tree_get_lock(tree), &mtr); /* Check ordering etc. of records */ if (!page_validate(page, index)) { fprintf(stderr, "Error in page %lu in index %s\n", buf_frame_get_page_no(page), index->name); ret = FALSE; } if (level == 0) { if (!btr_index_page_validate(page, index)) { fprintf(stderr, "Error in page %lu in index %s, level %lu\n", buf_frame_get_page_no(page), index->name, level); ret = FALSE; } } ut_a(btr_page_get_level(page, &mtr) == level); right_page_no = btr_page_get_next(page, &mtr); left_page_no = btr_page_get_prev(page, &mtr); ut_a((page_get_n_recs(page) > 0) || ((level == 0) && (buf_frame_get_page_no(page) == dict_tree_get_page(tree)))); if (right_page_no != FIL_NULL) { right_page = btr_page_get(space, right_page_no, RW_X_LATCH, &mtr); if (cmp_rec_rec(page_rec_get_prev(page_get_supremum_rec(page)), page_rec_get_next(page_get_infimum_rec(right_page)), UT_LIST_GET_FIRST(tree->tree_indexes)) >= 0) { fprintf(stderr, "InnoDB: Error on pages %lu and %lu in index %s\n", buf_frame_get_page_no(page), right_page_no, index->name); fprintf(stderr, "InnoDB: records in wrong order on adjacent pages\n"); rec_sprintf(err_buf, 900, page_rec_get_prev(page_get_supremum_rec(page))); fprintf(stderr, "InnoDB: record %s\n", err_buf); rec_sprintf(err_buf, 900, page_rec_get_next(page_get_infimum_rec(right_page))); fprintf(stderr, "InnoDB: record %s\n", err_buf); ret = FALSE; } } if (level > 0 && left_page_no == FIL_NULL) { ut_a(REC_INFO_MIN_REC_FLAG & rec_get_info_bits( page_rec_get_next(page_get_infimum_rec(page)))); } if (buf_frame_get_page_no(page) != dict_tree_get_page(tree)) { /* Check father node pointers */ node_ptr = btr_page_get_father_node_ptr(tree, page, &mtr); if (btr_node_ptr_get_child_page_no(node_ptr) != buf_frame_get_page_no(page) || node_ptr != btr_page_get_father_for_rec(tree, page, page_rec_get_prev(page_get_supremum_rec(page)), &mtr)) { fprintf(stderr, "InnoDB: Error on page %lu in index %s\n", buf_frame_get_page_no(page), index->name); fprintf(stderr, "InnoDB: node pointer to the page is wrong\n"); rec_sprintf(err_buf, 900, node_ptr); fprintf(stderr, "InnoDB: node ptr %s\n", err_buf); fprintf(stderr, "InnoDB: node ptr child page n:o %lu\n", btr_node_ptr_get_child_page_no(node_ptr)); rec_sprintf(err_buf, 900, btr_page_get_father_for_rec(tree, page, page_rec_get_prev(page_get_supremum_rec(page)), &mtr)); fprintf(stderr, "InnoDB: record on page %s\n", err_buf); ret = FALSE; goto node_ptr_fails; } father_page = buf_frame_align(node_ptr); if (btr_page_get_level(page, &mtr) > 0) { heap = mem_heap_create(256); node_ptr_tuple = dict_tree_build_node_ptr( tree, page_rec_get_next( page_get_infimum_rec(page)), 0, heap, btr_page_get_level(page, &mtr)); if (cmp_dtuple_rec(node_ptr_tuple, node_ptr) != 0) { fprintf(stderr, "InnoDB: Error on page %lu in index %s\n", buf_frame_get_page_no(page), index->name); fprintf(stderr, "InnoDB: Error: node ptrs differ on levels > 0\n"); rec_sprintf(err_buf, 900, node_ptr); fprintf(stderr, "InnoDB: node ptr %s\n", err_buf); rec_sprintf(err_buf, 900, page_rec_get_next( page_get_infimum_rec(page))); fprintf(stderr, "InnoDB: first rec %s\n", err_buf); ret = FALSE; mem_heap_free(heap); goto node_ptr_fails; } mem_heap_free(heap); } if (left_page_no == FIL_NULL) { ut_a(node_ptr == page_rec_get_next( page_get_infimum_rec(father_page))); ut_a(btr_page_get_prev(father_page, &mtr) == FIL_NULL); } if (right_page_no == FIL_NULL) { ut_a(node_ptr == page_rec_get_prev( page_get_supremum_rec(father_page))); ut_a(btr_page_get_next(father_page, &mtr) == FIL_NULL); } if (right_page_no != FIL_NULL) { right_node_ptr = btr_page_get_father_node_ptr(tree, right_page, &mtr); if (page_rec_get_next(node_ptr) != page_get_supremum_rec(father_page)) { if (right_node_ptr != page_rec_get_next(node_ptr)) { ret = FALSE; fprintf(stderr, "InnoDB: node pointer to the right page is wrong\n"); fprintf(stderr, "InnoDB: Error on page %lu in index %s\n", buf_frame_get_page_no(page), index->name); } } else { right_father_page = buf_frame_align( right_node_ptr); if (right_node_ptr != page_rec_get_next( page_get_infimum_rec( right_father_page))) { ret = FALSE; fprintf(stderr, "InnoDB: node pointer 2 to the right page is wrong\n"); fprintf(stderr, "InnoDB: Error on page %lu in index %s\n", buf_frame_get_page_no(page), index->name); } if (buf_frame_get_page_no(right_father_page) != btr_page_get_next(father_page, &mtr)) { ret = FALSE; fprintf(stderr, "InnoDB: node pointer 3 to the right page is wrong\n"); fprintf(stderr, "InnoDB: Error on page %lu in index %s\n", buf_frame_get_page_no(page), index->name); } } } } node_ptr_fails: mtr_commit(&mtr); if (right_page_no != FIL_NULL) { mtr_start(&mtr); page = btr_page_get(space, right_page_no, RW_X_LATCH, &mtr); goto loop; } return(ret); } /****************************************************************** Checks the consistency of an index tree. */ ibool btr_validate_tree( /*==============*/ /* out: TRUE if ok */ dict_tree_t* tree) /* in: tree */ { mtr_t mtr; page_t* root; ulint i; ulint n; mtr_start(&mtr); mtr_x_lock(dict_tree_get_lock(tree), &mtr); root = btr_root_get(tree, &mtr); n = btr_page_get_level(root, &mtr); for (i = 0; i <= n; i++) { if (!btr_validate_level(tree, n - i)) { mtr_commit(&mtr); return(FALSE); } } mtr_commit(&mtr); return(TRUE); }