/** * flush the backend * * @remark this function is called during ham_flush @note This is a B+-tree 'backend' method. */ static ham_status_t my_fun_flush(ham_btree_t *be) { ham_db_t *db=be_get_db(be); db_indexdata_t *indexdata=env_get_indexdata_ptr(db_get_env(db), db_get_indexdata_offset(db)); /* * nothing to do if the backend was not touched */ if (!be_is_dirty(be)) return (0); index_set_max_keys(indexdata, btree_get_maxkeys(be)); index_set_keysize(indexdata, be_get_keysize(be)); index_set_self(indexdata, btree_get_rootpage(be)); index_set_flags(indexdata, be_get_flags(be)); index_set_recno(indexdata, be_get_recno(be)); index_clear_reserved(indexdata); env_set_dirty(db_get_env(db)); be_set_dirty(be, HAM_FALSE); return (0); }
static void print_database(ham_db_t *db, ham_u16_t dbname, int full) { ham_btree_t *be; ham_cursor_t *cursor; ham_status_t st; ham_key_t key; ham_record_t rec; unsigned num_items=0, ext_keys=0, min_key_size=0xffffffff, max_key_size=0, min_rec_size=0xffffffff, max_rec_size=0, total_key_size=0, total_rec_size=0; be=(ham_btree_t *)db_get_backend(db); memset(&key, 0, sizeof(key)); memset(&rec, 0, sizeof(rec)); printf("\n"); printf(" database %d (0x%x)\n", (int)dbname, (int)dbname); printf(" max key size: %u\n", be_get_keysize(be)); printf(" max keys per page: %u\n", btree_get_maxkeys(be)); printf(" address of root page: %llu\n", (long long unsigned int)btree_get_rootpage(be)); printf(" flags: 0x%04x\n", db_get_rt_flags(db)); if (!full) return; st=ham_cursor_create(db, 0, 0, &cursor); if (st!=HAM_SUCCESS) error("ham_cursor_create", st); while (1) { st=ham_cursor_move(cursor, &key, &rec, HAM_CURSOR_NEXT); if (st!=HAM_SUCCESS) { /* reached end of the database? */ if (st==HAM_KEY_NOT_FOUND) break; else error("ham_cursor_next", st); } num_items++; if (key.size<min_key_size) min_key_size=key.size; if (key.size>max_key_size) max_key_size=key.size; if (rec.size<min_rec_size) min_rec_size=rec.size; if (rec.size>max_rec_size) max_rec_size=rec.size; if (key.size>db_get_keysize(db)) ext_keys++; total_key_size+=key.size; total_rec_size+=rec.size; } ham_cursor_close(cursor); printf(" number of items: %u\n", num_items); if (num_items==0) return; printf(" average key size: %u\n", total_key_size/num_items); printf(" minimum key size: %u\n", min_key_size); printf(" maximum key size: %u\n", max_key_size); printf(" number of extended keys:%u\n", ext_keys); printf(" total keys (bytes): %u\n", total_key_size); printf(" average record size: %u\n", total_rec_size/num_items); printf(" minimum record size: %u\n", min_rec_size); printf(" maximum record size: %u\n", min_rec_size); printf(" total records (bytes): %u\n", total_rec_size); }
ham_status_t btree_find_cursor(ham_btree_t *be, ham_bt_cursor_t *cursor, ham_key_t *key, ham_record_t *record, ham_u32_t flags) { ham_status_t st; ham_page_t *page = NULL; btree_node_t *node = NULL; int_key_t *entry; ham_s32_t idx = -1; ham_db_t *db=be_get_db(be); find_hints_t hints = {flags, flags, 0, HAM_FALSE, HAM_FALSE, 1}; btree_find_get_hints(&hints, db, key); if (hints.key_is_out_of_bounds) { stats_update_find_fail_oob(db, &hints); return HAM_KEY_NOT_FOUND; } if (hints.try_fast_track) { /* * see if we get a sure hit within this btree leaf; if not, revert to * regular scan * * As this is a speed-improvement hint re-using recent material, the * page should still sit in the cache, or we're using old info, which * should be discarded. */ st = db_fetch_page(&page, db, hints.leaf_page_addr, DB_ONLY_FROM_CACHE); ham_assert(st ? !page : 1, (0)); if (st) return st; if (page) { node=ham_page_get_btree_node(page); ham_assert(btree_node_is_leaf(node), (0)); ham_assert(btree_node_get_count(node) >= 3, (0)); /* edges + middle match */ idx = btree_node_search_by_key(db, page, key, hints.flags); /* * if we didn't hit a match OR a match at either edge, FAIL. * A match at one of the edges is very risky, as this can also * signal a match far away from the current node, so we need * the full tree traversal then. */ if (idx <= 0 || idx >= btree_node_get_count(node) - 1) { idx = -1; } /* * else: we landed in the middle of the node, so we don't need to * traverse the entire tree now. */ } /* Reset any errors which may have been collected during the hinting * phase -- this is done by setting 'idx = -1' above as that effectively * clears the possible error code stored in there when (idx < -1) */ } if (idx == -1) { /* get the address of the root page */ if (!btree_get_rootpage(be)) { stats_update_find_fail(db, &hints); return HAM_KEY_NOT_FOUND; } /* load the root page */ st=db_fetch_page(&page, db, btree_get_rootpage(be), 0); ham_assert(st ? !page : 1, (0)); if (!page) { ham_assert(st, (0)); stats_update_find_fail(db, &hints); return st ? st : HAM_INTERNAL_ERROR; } /* now traverse the root to the leaf nodes, till we find a leaf */ node=ham_page_get_btree_node(page); if (!btree_node_is_leaf(node)) { /* signal 'don't care' when we have multiple pages; we resolve this once we've got a hit further down */ if (hints.flags & (HAM_FIND_LT_MATCH | HAM_FIND_GT_MATCH)) hints.flags |= (HAM_FIND_LT_MATCH | HAM_FIND_GT_MATCH); for (;;) { hints.cost++; st=btree_traverse_tree(&page, 0, db, page, key); if (!page) { stats_update_find_fail(db, &hints); return st ? st : HAM_KEY_NOT_FOUND; } node=ham_page_get_btree_node(page); if (btree_node_is_leaf(node)) break; } } /* check the leaf page for the key */ idx=btree_node_search_by_key(db, page, key, hints.flags); if (idx < -1) { stats_update_find_fail(db, &hints); return (ham_status_t)idx; } } /* end of regular search */ /* * When we are performing an approximate match, the worst case * scenario is where we've picked the wrong side of the fence * while sitting at a page/node boundary: that's what this * next piece of code resolves: * * essentially it moves one record forwards or backward when * the flags tell us this is mandatory and we're not yet in the proper * position yet. * * The whole trick works, because the code above detects when * we need to traverse a multi-page btree -- where this worst-case * scenario can happen -- and adjusted the flags to accept * both LT and GT approximate matches so that btree_node_search_by_key() * will be hard pressed to return a 'key not found' signal (idx==-1), * instead delivering the nearest LT or GT match; all we need to * do now is ensure we've got the right one and if not, * shift by one. */ if (idx >= 0) { if ((ham_key_get_intflags(key) & KEY_IS_APPROXIMATE) && (hints.original_flags & (HAM_FIND_LT_MATCH | HAM_FIND_GT_MATCH)) != (HAM_FIND_LT_MATCH | HAM_FIND_GT_MATCH)) { if ((ham_key_get_intflags(key) & KEY_IS_GT) && (hints.original_flags & HAM_FIND_LT_MATCH)) { /* * if the index-1 is still in the page, just decrement the * index */ if (idx > 0) { idx--; } else { /* * otherwise load the left sibling page */ if (!btree_node_get_left(node)) { stats_update_find_fail(db, &hints); ham_assert(node == ham_page_get_btree_node(page), (0)); stats_update_any_bound(db, page, key, hints.original_flags, -1); return HAM_KEY_NOT_FOUND; } hints.cost++; st = db_fetch_page(&page, db, btree_node_get_left(node), 0); ham_assert(st ? !page : 1, (0)); if (!page) { ham_assert(st, (0)); stats_update_find_fail(db, &hints); return st ? st : HAM_INTERNAL_ERROR; } node = ham_page_get_btree_node(page); idx = btree_node_get_count(node) - 1; } ham_key_set_intflags(key, (ham_key_get_intflags(key) & ~KEY_IS_APPROXIMATE) | KEY_IS_LT); } else if ((ham_key_get_intflags(key) & KEY_IS_LT) && (hints.original_flags & HAM_FIND_GT_MATCH)) { /* * if the index+1 is still in the page, just increment the * index */ if (idx + 1 < btree_node_get_count(node)) { idx++; } else { /* * otherwise load the right sibling page */ if (!btree_node_get_right(node)) { stats_update_find_fail(db, &hints); ham_assert(node == ham_page_get_btree_node(page), (0)); stats_update_any_bound(db, page, key, hints.original_flags, -1); return HAM_KEY_NOT_FOUND; } hints.cost++; st = db_fetch_page(&page, db, btree_node_get_right(node), 0); if (!page) { ham_assert(st, (0)); stats_update_find_fail(db, &hints); return st ? st : HAM_INTERNAL_ERROR; } node = ham_page_get_btree_node(page); idx = 0; } ham_key_set_intflags(key, (ham_key_get_intflags(key) & ~KEY_IS_APPROXIMATE) | KEY_IS_GT); } } else if (!(ham_key_get_intflags(key) & KEY_IS_APPROXIMATE) && !(hints.original_flags & HAM_FIND_EXACT_MATCH) && (hints.original_flags != 0)) { /* * 'true GT/LT' has been added @ 2009/07/18 to complete * the EQ/LEQ/GEQ/LT/GT functionality; * * 'true LT/GT' is simply an extension upon the already existing * LEQ/GEQ logic just above; all we do here is move one record * up/down as it just happens that we get an exact ('equal') * match here. * * The fact that the LT/GT constants share their bits with the * LEQ/GEQ flags so that LEQ==(LT|EXACT) and GEQ==(GT|EXACT) * ensures that we can restrict our work to a simple adjustment * right here; everything else has already been taken of by the * LEQ/GEQ logic in the section above when the key has been * flagged with the KEY_IS_APPROXIMATE flag. */ if (hints.original_flags & HAM_FIND_LT_MATCH) { /* * if the index-1 is still in the page, just decrement the * index */ if (idx > 0) { idx--; ham_key_set_intflags(key, (ham_key_get_intflags(key) & ~KEY_IS_APPROXIMATE) | KEY_IS_LT); } else { /* * otherwise load the left sibling page */ if (!btree_node_get_left(node)) { /* when an error is otherwise unavoidable, see if we have an escape route through GT? */ if (hints.original_flags & HAM_FIND_GT_MATCH) { /* * if the index+1 is still in the page, just * increment the index */ if (idx + 1 < btree_node_get_count(node)) { idx++; } else { /* * otherwise load the right sibling page */ if (!btree_node_get_right(node)) { stats_update_find_fail(db, &hints); ham_assert(node == ham_page_get_btree_node(page), (0)); stats_update_any_bound(db, page, key, hints.original_flags, -1); return HAM_KEY_NOT_FOUND; } hints.cost++; st = db_fetch_page(&page, db, btree_node_get_right(node), 0); if (!page) { ham_assert(st, (0)); stats_update_find_fail(db, &hints); return st ? st : HAM_INTERNAL_ERROR; } node = ham_page_get_btree_node(page); idx = 0; } ham_key_set_intflags(key, (ham_key_get_intflags(key) & ~KEY_IS_APPROXIMATE) | KEY_IS_GT); } else { stats_update_find_fail(db, &hints); ham_assert(node == ham_page_get_btree_node(page), (0)); stats_update_any_bound(db, page, key, hints.original_flags, -1); return HAM_KEY_NOT_FOUND; } } else { hints.cost++; st = db_fetch_page(&page, db, btree_node_get_left(node), 0); if (!page) { ham_assert(st, (0)); stats_update_find_fail(db, &hints); return st ? st : HAM_INTERNAL_ERROR; } node = ham_page_get_btree_node(page); idx = btree_node_get_count(node) - 1; ham_key_set_intflags(key, (ham_key_get_intflags(key) & ~KEY_IS_APPROXIMATE) | KEY_IS_LT); } } } else if (hints.original_flags & HAM_FIND_GT_MATCH) { /* * if the index+1 is still in the page, just increment the * index */ if (idx + 1 < btree_node_get_count(node)) { idx++; } else { /* * otherwise load the right sibling page */ if (!btree_node_get_right(node)) { stats_update_find_fail(db, &hints); ham_assert(node == ham_page_get_btree_node(page), (0)); stats_update_any_bound(db, page, key, hints.original_flags, -1); return HAM_KEY_NOT_FOUND; } hints.cost++; st = db_fetch_page(&page, db, btree_node_get_right(node), 0); if (!page) { ham_assert(st, (0)); stats_update_find_fail(db, &hints); return st ? st : HAM_INTERNAL_ERROR; } node = ham_page_get_btree_node(page); idx = 0; } ham_key_set_intflags(key, (ham_key_get_intflags(key) & ~KEY_IS_APPROXIMATE) | KEY_IS_GT); } } } if (idx<0) { stats_update_find_fail(db, &hints); ham_assert(node, (0)); ham_assert(page, (0)); ham_assert(node == ham_page_get_btree_node(page), (0)); stats_update_any_bound(db, page, key, hints.original_flags, -1); return HAM_KEY_NOT_FOUND; } /* load the entry, and store record ID and key flags */ entry=btree_node_get_key(db, node, idx); /* set the cursor-position to this key */ if (cursor) { ham_assert(!(bt_cursor_get_flags(cursor)&BT_CURSOR_FLAG_UNCOUPLED), ("coupling an uncoupled cursor, but need a nil-cursor")); ham_assert(!(bt_cursor_get_flags(cursor)&BT_CURSOR_FLAG_COUPLED), ("coupling a coupled cursor, but need a nil-cursor")); page_add_cursor(page, (ham_cursor_t *)cursor); bt_cursor_set_flags(cursor, bt_cursor_get_flags(cursor)|BT_CURSOR_FLAG_COUPLED); bt_cursor_set_coupled_page(cursor, page); bt_cursor_set_coupled_index(cursor, idx); } /* * during util_read_key and util_read_record, new pages might be needed, * and the page at which we're pointing could be moved out of memory; * that would mean that the cursor would be uncoupled, and we're losing * the 'entry'-pointer. therefore we 'lock' the page by incrementing * the reference counter */ page_add_ref(page); ham_assert(btree_node_is_leaf(node), ("iterator points to internal node")); /* no need to load the key if we have an exact match: */ if (key && (ham_key_get_intflags(key) & KEY_IS_APPROXIMATE)) { ham_status_t st=util_read_key(db, entry, key); if (st) { page_release_ref(page); stats_update_find_fail(db, &hints); return (st); } } if (record) { ham_status_t st; record->_intflags=key_get_flags(entry); record->_rid=key_get_ptr(entry); st=util_read_record(db, record, flags); if (st) { page_release_ref(page); stats_update_find_fail(db, &hints); return (st); } } page_release_ref(page); stats_update_find(db, page, &hints); ham_assert(node == ham_page_get_btree_node(page), (0)); stats_update_any_bound(db, page, key, hints.original_flags, idx); return (0); }
static ham_status_t __insert_cursor(ham_btree_t *be, ham_key_t *key, ham_record_t *record, ham_bt_cursor_t *cursor, insert_hints_t *hints) { ham_status_t st; ham_page_t *root; ham_db_t *db=be_get_db(be); ham_env_t *env = db_get_env(db); insert_scratchpad_t scratchpad; ham_assert(hints->force_append == HAM_FALSE, (0)); ham_assert(hints->force_prepend == HAM_FALSE, (0)); /* * initialize the scratchpad */ memset(&scratchpad, 0, sizeof(scratchpad)); scratchpad.be=be; scratchpad.record=record; scratchpad.cursor=cursor; /* * get the root-page... */ ham_assert(btree_get_rootpage(be)!=0, ("btree has no root page")); st=db_fetch_page(&root, db, btree_get_rootpage(be), 0); ham_assert(st ? root == NULL : 1, (0)); if (st) return st; /* * ... and start the recursion */ st=__insert_recursive(root, key, 0, &scratchpad, hints); /* * if the root page was split, we have to create a new * root page. */ if (st==SPLIT) { ham_page_t *newroot; btree_node_t *node; /* * the root-page will be changed... */ st=ham_log_add_page_before(root); if (st) return (st); /* * allocate a new root page */ st=db_alloc_page(&newroot, db, PAGE_TYPE_B_ROOT, 0); ham_assert(st ? newroot == NULL : 1, (0)); if (st) return (st); ham_assert(page_get_owner(newroot), ("")); /* clear the node header */ memset(page_get_payload(newroot), 0, sizeof(btree_node_t)); stats_page_is_nuked(db, root, HAM_TRUE); /* * insert the pivot element and the ptr_left */ node=ham_page_get_btree_node(newroot); btree_node_set_ptr_left(node, btree_get_rootpage(be)); st=__insert_nosplit(newroot, &scratchpad.key, scratchpad.rid, scratchpad.record, scratchpad.cursor, hints); ham_assert(!(scratchpad.key.flags & HAM_KEY_USER_ALLOC), (0)); scratchpad.cursor=0; /* don't overwrite cursor if __insert_nosplit is called again */ if (st) { ham_assert(!(scratchpad.key.flags & HAM_KEY_USER_ALLOC), (0)); if (scratchpad.key.data) allocator_free(env_get_allocator(env), scratchpad.key.data); return (st); } /* * set the new root page * * !! * do NOT delete the old root page - it's still in use! * * also don't forget to flush the backend - otherwise the header * page of the database will not contain the updated information. * The backend is flushed when the database is closed, but if * recovery is enabled then the flush here is critical. */ btree_set_rootpage(be, page_get_self(newroot)); be_set_dirty(be, HAM_TRUE); be->_fun_flush(be); /* * As we re-purpose a page, we will reset its pagecounter * as well to signal its first use as the new type assigned * here. */ if (env_get_cache(env) && (page_get_type(root)!=PAGE_TYPE_B_INDEX)) cache_update_page_access_counter(root, env_get_cache(env), 0); page_set_type(root, PAGE_TYPE_B_INDEX); page_set_dirty(root, env); page_set_dirty(newroot, env); /* the root page was modified (btree_set_rootpage) - make sure that * it's logged */ if (env_get_rt_flags(env)&HAM_ENABLE_RECOVERY) { st=txn_add_page(env_get_txn(env), env_get_header_page(env), HAM_TRUE); if (st) return (st); } } /* * release the scratchpad-memory and return to caller */ ham_assert(!(scratchpad.key.flags & HAM_KEY_USER_ALLOC), (0)); if (scratchpad.key.data) allocator_free(env_get_allocator(env), scratchpad.key.data); return (st); }