/* -*- mode: C; c-basic-offset: 4 -*- */ #ident "Copyright (c) 2007, 2008 Tokutek Inc. All rights reserved." /* Recover an env. The logs are in argv[1]. The new database is created in the cwd. */ // Test: // cd ../src/tests/tmpdir // ../../../newbrt/recover ../dir.test_log2.c.tdb #include "cachetable.h" #include "key.h" #include "log-internal.h" #include "log_header.h" #include "toku_assert.h" #include #include #include #include #include //#define DO_VERIFY_COUNTS #ifdef DO_VERIFY_COUNTS #define VERIFY_COUNTS(n) toku_verify_counts(n) #else #define VERIFY_COUNTS(n) ((void)0) #endif static DB * const null_db=0; // These data structures really should be part of a recovery data structure. Recovery could be multithreaded (on different environments...) But this is OK since recovery can only happen in one static CACHETABLE ct; static struct cf_pair { FILENUM filenum; CACHEFILE cf; BRT brt; // set to zero on an fopen, but filled in when an fheader is seen. } *cf_pairs; static int n_cf_pairs=0, max_cf_pairs=0;; int toku_recover_init (void) { int r = toku_create_cachetable(&ct, 1<<25, (LSN){0}, 0); return r; } void toku_recover_cleanup (void) { int i; for (i=0; i=0); toku_free(fixed_fname); toku_free_BYTESTRING(fname); } int toku_recover_note_cachefile (FILENUM fnum, CACHEFILE cf, BRT brt) { if (max_cf_pairs==0) { n_cf_pairs=1; max_cf_pairs=2; MALLOC_N(max_cf_pairs, cf_pairs); if (cf_pairs==0) return errno; } else { if (n_cf_pairs>=max_cf_pairs) { max_cf_pairs*=2; cf_pairs = toku_realloc(cf_pairs, max_cf_pairs*sizeof(*cf_pairs)); } n_cf_pairs++; } cf_pairs[n_cf_pairs-1].filenum = fnum; cf_pairs[n_cf_pairs-1].cf = cf; cf_pairs[n_cf_pairs-1].brt = brt; return 0; } static int find_cachefile (FILENUM fnum, struct cf_pair **cf_pair) { int i; for (i=0; idirty=0; h->flags = header.flags; h->nodesize = header.nodesize; h->freelist = header.freelist; h->unused_memory = header.unused_memory; h->n_named_roots = header.n_named_roots; if ((signed)header.n_named_roots==-1) { h->unnamed_root = header.u.one.root; } else { assert(0); } toku_cachetable_put(pair->cf, 0, h, 0, toku_brtheader_flush_callback, toku_brtheader_fetch_callback, 0); if (pair->brt) { free(pair->brt->h); } else { MALLOC(pair->brt); pair->brt->cf = pair->cf; pair->brt->database_name = 0; // Special case, we don't know or care what the database name is for recovery. list_init(&pair->brt->cursors); pair->brt->compare_fun = 0; pair->brt->dup_compare = 0; pair->brt->db = 0; pair->brt->skey = pair->brt->sval = 0; } pair->brt->h = h; pair->brt->nodesize = h->nodesize; pair->brt->flags = h->nodesize; r = toku_unpin_brt_header(pair->brt); assert(r==0); } void toku_recover_newbrtnode (LSN lsn, FILENUM filenum,DISKOFF diskoff,u_int32_t height,u_int32_t nodesize,u_int8_t is_dup_sort,u_int32_t rand4fingerprint) { int r; struct cf_pair *pair = NULL; r = find_cachefile(filenum, &pair); assert(r==0); TAGMALLOC(BRTNODE, n); n->nodesize = nodesize; n->thisnodename = diskoff; n->log_lsn = n->disk_lsn = lsn; //printf("%s:%d %p->disk_lsn=%"PRId64"\n", __FILE__, __LINE__, n, n->disk_lsn.lsn); n->layout_version = 2; n->height = height; n->rand4fingerprint = rand4fingerprint; n->flags = is_dup_sort ? TOKU_DB_DUPSORT : 0; // Don't have TOKU_DB_DUP ??? n->local_fingerprint = 0; // nothing there yet n->dirty = 1; if (height==0) { r=toku_pma_create(&n->u.l.buffer, toku_dont_call_this_compare_fun, null_db, filenum, nodesize, 0); assert(r==0); n->u.l.n_bytes_in_buffer=0; } else { n->u.n.n_children = 0; n->u.n.totalchildkeylens = 0; n->u.n.n_bytes_in_buffers = 0; MALLOC_N(3,n->u.n.childinfos); MALLOC_N(2,n->u.n.childkeys); } // Now put it in the cachetable toku_cachetable_put(pair->cf, diskoff, n, toku_serialize_brtnode_size(n), toku_brtnode_flush_callback, toku_brtnode_fetch_callback, 0); VERIFY_COUNTS(n); n->log_lsn = lsn; r = toku_cachetable_unpin(pair->cf, diskoff, 1, toku_serialize_brtnode_size(n)); assert(r==0); } static void recover_setup_node (FILENUM filenum, DISKOFF diskoff, CACHEFILE *cf, BRTNODE *resultnode) { struct cf_pair *pair = NULL; int r = find_cachefile(filenum, &pair); assert(r==0); assert(pair->brt); void *node_v; r = toku_cachetable_get_and_pin(pair->cf, diskoff, &node_v, NULL, toku_brtnode_flush_callback, toku_brtnode_fetch_callback, pair->brt); assert(r==0); BRTNODE node = node_v; *resultnode = node; *cf = pair->cf; } void toku_recover_brtdeq (LSN lsn, FILENUM filenum, DISKOFF diskoff, u_int32_t childnum, TXNID xid, u_int32_t typ, BYTESTRING key, BYTESTRING data, u_int32_t oldfingerprint, u_int32_t newfingerprint) { CACHEFILE cf; BRTNODE node; int r; recover_setup_node(filenum, diskoff, &cf, &node); assert(node->height>0); //printf("deq: %lld expected_old_fingerprint=%08x actual=%08x new=%08x\n", diskoff, oldfingerprint, node->local_fingerprint, newfingerprint); assert(node->local_fingerprint==oldfingerprint); bytevec actual_key, actual_data; ITEMLEN actual_keylen, actual_datalen; u_int32_t actual_type; TXNID actual_xid; assert(childnum<(u_int32_t)node->u.n.n_children); r = toku_fifo_peek(BNC_BUFFER(node, childnum), &actual_key, &actual_keylen, &actual_data, &actual_datalen, &actual_type, &actual_xid); assert(r==0); assert(actual_keylen==(ITEMLEN)key.len); assert(memcmp(actual_key, key.data, actual_keylen)==0); assert(actual_datalen=data.len); assert(memcmp(actual_data, data.data, actual_datalen)==0); assert(actual_type==typ); assert(actual_xid==xid); u_int32_t sizediff = key.len + data.len + KEY_VALUE_OVERHEAD + BRT_CMD_OVERHEAD; node->local_fingerprint = newfingerprint; node->log_lsn = lsn; node->u.n.n_bytes_in_buffers -= sizediff; BNC_NBYTESINBUF(node, childnum) -= sizediff; r = toku_fifo_deq(BNC_BUFFER(node, childnum)); // don't deq till were' done looking at the data. r = toku_cachetable_unpin(cf, diskoff, 1, toku_serialize_brtnode_size(node)); assert(r==0); toku_free(key.data); toku_free(data.data); } void toku_recover_brtenq (LSN lsn, FILENUM filenum, DISKOFF diskoff, u_int32_t childnum, TXNID xid, u_int32_t typ, BYTESTRING key, BYTESTRING data, u_int32_t oldfingerprint, u_int32_t newfingerprint) { CACHEFILE cf; BRTNODE node; int r; recover_setup_node(filenum, diskoff, &cf, &node); assert(node->height>0); //printf("enq: %lld expected_old_fingerprint=%08x actual=%08x new=%08x\n", diskoff, oldfingerprint, node->local_fingerprint, newfingerprint); assert(node->local_fingerprint==oldfingerprint); r = toku_fifo_enq(BNC_BUFFER(node, childnum), key.data, key.len, data.data, data.len, typ, xid); assert(r==0); node->local_fingerprint = newfingerprint; node->log_lsn = lsn; u_int32_t sizediff = key.len + data.len + KEY_VALUE_OVERHEAD + BRT_CMD_OVERHEAD; r = toku_cachetable_unpin(cf, diskoff, 1, toku_serialize_brtnode_size(node)); assert(r==0); node->u.n.n_bytes_in_buffers += sizediff; BNC_NBYTESINBUF(node, childnum) += sizediff; toku_free(key.data); toku_free(data.data); } void toku_recover_addchild (LSN lsn, FILENUM filenum, DISKOFF diskoff, u_int32_t childnum, DISKOFF child, u_int32_t childfingerprint) { CACHEFILE cf; BRTNODE node; recover_setup_node(filenum, diskoff, &cf, &node); assert(node->height>0); assert(childnum <= (unsigned)node->u.n.n_children); unsigned int i; REALLOC_N(node->u.n.n_children+1, node->u.n.childinfos); REALLOC_N(node->u.n.n_children, node->u.n.childkeys); for (i=node->u.n.n_children; i>childnum; i--) { node->u.n.childinfos[i]=node->u.n.childinfos[i-1]; BNC_NBYTESINBUF(node,i) = BNC_NBYTESINBUF(node,i-1); assert(i>=2); node->u.n.childkeys [i-1] = node->u.n.childkeys [i-2]; } if (childnum>0) { node->u.n.childkeys [childnum-1] = 0; } BNC_DISKOFF(node, childnum) = child; BNC_SUBTREE_FINGERPRINT(node, childnum) = childfingerprint; int r= toku_fifo_create(&BNC_BUFFER(node, childnum)); assert(r==0); BNC_NBYTESINBUF(node, childnum) = 0; node->u.n.n_children++; node->log_lsn = lsn; r = toku_cachetable_unpin(cf, diskoff, 1, toku_serialize_brtnode_size(node)); assert(r==0); } void toku_recover_delchild (LSN lsn, FILENUM filenum, DISKOFF diskoff, u_int32_t childnum, DISKOFF child, u_int32_t childfingerprint, BYTESTRING pivotkey) { struct cf_pair *pair = NULL; int r = find_cachefile(filenum, &pair); assert(r==0); void *node_v; assert(pair->brt); r = toku_cachetable_get_and_pin(pair->cf, diskoff, &node_v, NULL, toku_brtnode_flush_callback, toku_brtnode_fetch_callback, pair->brt); assert(r==0); BRTNODE node = node_v; assert(node->height>0); assert(childnum < (unsigned)node->u.n.n_children); assert(node->u.n.childinfos[childnum].subtree_fingerprint == childfingerprint); assert(BNC_DISKOFF(node, childnum)==child); assert(toku_fifo_n_entries(BNC_BUFFER(node,childnum))==0); assert(BNC_NBYTESINBUF(node,childnum)==0); assert(node->u.n.n_children>2); // Must be at least two children. u_int32_t i; assert(childnum>0); node->u.n.totalchildkeylens -= toku_brt_pivot_key_len(pair->brt, node->u.n.childkeys[childnum-1]); toku_free((void*)node->u.n.childkeys[childnum-1]); toku_fifo_free(&BNC_BUFFER(node,childnum)); for (i=childnum+1; i<(unsigned)node->u.n.n_children; i++) { node->u.n.childinfos[i-1] = node->u.n.childinfos[i]; BNC_NBYTESINBUF(node,i-1) = BNC_NBYTESINBUF(node,i); node->u.n.childkeys[i-2] = node->u.n.childkeys[i-1]; } node->u.n.n_children--; node->log_lsn = lsn; r = toku_cachetable_unpin(pair->cf, diskoff, 1, toku_serialize_brtnode_size(node)); assert(r==0); toku_free(pivotkey.data); } void toku_recover_setchild (LSN lsn, FILENUM filenum, DISKOFF diskoff, u_int32_t childnum, DISKOFF UU(oldchild), DISKOFF newchild) { struct cf_pair *pair = NULL; int r = find_cachefile(filenum, &pair); assert(r==0); void *node_v; assert(pair->brt); r = toku_cachetable_get_and_pin(pair->cf, diskoff, &node_v, NULL, toku_brtnode_flush_callback, toku_brtnode_fetch_callback, pair->brt); assert(r==0); BRTNODE node = node_v; assert(node->height>0); assert(childnum < (unsigned)node->u.n.n_children); BNC_DISKOFF(node, childnum) = newchild; node->log_lsn = lsn; r = toku_cachetable_unpin(pair->cf, diskoff, 1, toku_serialize_brtnode_size(node)); assert(r==0); } void toku_recover_setpivot (LSN lsn, FILENUM filenum, DISKOFF diskoff, u_int32_t childnum, BYTESTRING pivotkey) { struct cf_pair *pair = NULL; int r = find_cachefile(filenum, &pair); assert(r==0); void *node_v; assert(pair->brt); r = toku_cachetable_get_and_pin(pair->cf, diskoff, &node_v, NULL, toku_brtnode_flush_callback, toku_brtnode_fetch_callback, pair->brt); assert(r==0); BRTNODE node = node_v; assert(node->height>0); struct kv_pair *new_pivot = kv_pair_malloc(pivotkey.data, pivotkey.len, 0, 0); node->u.n.childkeys[childnum] = new_pivot; node->u.n.totalchildkeylens += toku_brt_pivot_key_len(pair->brt, node->u.n.childkeys[childnum]); node->log_lsn = lsn; r = toku_cachetable_unpin(pair->cf, diskoff, 1, toku_serialize_brtnode_size(node)); assert(r==0); toku_free(pivotkey.data); } void toku_recover_changechildfingerprint (LSN lsn, FILENUM filenum, DISKOFF diskoff, u_int32_t childnum, u_int32_t UU(oldfingerprint), u_int32_t newfingerprint) { struct cf_pair *pair = NULL; int r = find_cachefile(filenum, &pair); assert(r==0); void *node_v; assert(pair->brt); r = toku_cachetable_get_and_pin(pair->cf, diskoff, &node_v, NULL, toku_brtnode_flush_callback, toku_brtnode_fetch_callback, pair->brt); assert(r==0); BRTNODE node = node_v; assert(node->height>0); assert((signed)childnum <= node->u.n.n_children); // we allow the childnum to be one too large. BNC_SUBTREE_FINGERPRINT(node, childnum) = newfingerprint; node->log_lsn = lsn; r = toku_cachetable_unpin(pair->cf, diskoff, 1, toku_serialize_brtnode_size(node)); assert(r==0); } void toku_recover_fopen (LSN UU(lsn), TXNID UU(txnid), BYTESTRING fname, FILENUM filenum) { char *fixedfname = fixup_fname(&fname); CACHEFILE cf; int fd = open(fixedfname, O_RDWR, 0); assert(fd>=0); BRT MALLOC(brt); assert(errno==0 && brt!=0); brt->database_name = fixedfname; brt->h=0; list_init(&brt->cursors); brt->compare_fun = 0; brt->dup_compare = 0; brt->db = 0; int r = toku_cachetable_openfd(&cf, ct, fd, brt); assert(r==0); brt->skey = brt->sval = 0; brt->cf=cf; toku_recover_note_cachefile(filenum, cf, brt); toku_free_BYTESTRING(fname); } void toku_recover_insertinleaf (LSN lsn, TXNID UU(txnid), FILENUM filenum, DISKOFF diskoff, u_int32_t pmaidx, BYTESTRING keybs, BYTESTRING databs) { struct cf_pair *pair = NULL; int r = find_cachefile(filenum, &pair); assert(r==0); void *node_v; assert(pair->brt); r = toku_cachetable_get_and_pin(pair->cf, diskoff, &node_v, NULL, toku_brtnode_flush_callback, toku_brtnode_fetch_callback, pair->brt); assert(r==0); BRTNODE node = node_v; assert(node->height==0); VERIFY_COUNTS(node); DBT key,data; r = toku_pma_set_at_index(node->u.l.buffer, pmaidx, toku_fill_dbt(&key, keybs.data, keybs.len), toku_fill_dbt(&data, databs.data, databs.len)); assert(r==0); node->local_fingerprint += node->rand4fingerprint*toku_calccrc32_kvpair(keybs.data, keybs.len, databs.data, databs.len); node->u.l.n_bytes_in_buffer += PMA_ITEM_OVERHEAD + KEY_VALUE_OVERHEAD + keybs.len + databs.len; // PMA_ITERATE_IDX(node->u.l.buffer, idx, skey, keylen __attribute__((__unused__)), sdata, datalen __attribute__((__unused__)), // printf("%d: %s %s\n", idx, (char*)skey, (char*)sdata)); VERIFY_COUNTS(node); node->log_lsn = lsn; r = toku_cachetable_unpin(pair->cf, diskoff, 1, toku_serialize_brtnode_size(node)); assert(r==0); toku_free_BYTESTRING(keybs); toku_free_BYTESTRING(databs); } void toku_recover_deleteinleaf (LSN lsn, TXNID UU(txnid), FILENUM filenum, DISKOFF diskoff, u_int32_t pmaidx, BYTESTRING keybs, BYTESTRING databs) { struct cf_pair *pair = NULL; int r = find_cachefile(filenum, &pair); assert(r==0); void *node_v; assert(pair->brt); r = toku_cachetable_get_and_pin(pair->cf, diskoff, &node_v, NULL, toku_brtnode_flush_callback, toku_brtnode_fetch_callback, pair->brt); assert(r==0); BRTNODE node = node_v; assert(node->height==0); VERIFY_COUNTS(node); r = toku_pma_clear_at_index(node->u.l.buffer, pmaidx); assert (r==0); node->local_fingerprint -= node->rand4fingerprint*toku_calccrc32_kvpair(keybs.data, keybs.len, databs.data, databs.len); node->u.l.n_bytes_in_buffer -= PMA_ITEM_OVERHEAD + KEY_VALUE_OVERHEAD + keybs.len + databs.len; VERIFY_COUNTS(node); node->log_lsn = lsn; r = toku_cachetable_unpin(pair->cf, diskoff, 1, toku_serialize_brtnode_size(node)); assert(r==0); toku_free_BYTESTRING(keybs); toku_free_BYTESTRING(databs); } // a newbrtnode should have been done before this void toku_recover_resizepma (LSN lsn, FILENUM filenum, DISKOFF diskoff, u_int32_t oldsize, u_int32_t newsize) { struct cf_pair *pair = NULL; int r = find_cachefile(filenum, &pair); assert(r==0); void *node_v; assert(pair->brt); r = toku_cachetable_get_and_pin (pair->cf, diskoff, &node_v, NULL, toku_brtnode_flush_callback, toku_brtnode_fetch_callback, pair->brt); assert(r==0); BRTNODE node = node_v; assert(node->height==0); r = toku_resize_pma_exactly (node->u.l.buffer, oldsize, newsize); assert(r==0); VERIFY_COUNTS(node); node->log_lsn = lsn; r = toku_cachetable_unpin(pair->cf, diskoff, 1, toku_serialize_brtnode_size(node)); assert(r==0); } void toku_recover_pmadistribute (LSN lsn, FILENUM filenum, DISKOFF old_diskoff, DISKOFF new_diskoff, INTPAIRARRAY fromto) { struct cf_pair *pair = NULL; int r = find_cachefile(filenum, &pair); assert(r==0); void *node_va, *node_vb; assert(pair->brt); r = toku_cachetable_get_and_pin(pair->cf, old_diskoff, &node_va, NULL, toku_brtnode_flush_callback, toku_brtnode_fetch_callback, pair->brt); assert(r==0); r = toku_cachetable_get_and_pin(pair->cf, new_diskoff, &node_vb, NULL, toku_brtnode_flush_callback, toku_brtnode_fetch_callback, pair->brt); assert(r==0); BRTNODE nodea = node_va; assert(nodea->height==0); BRTNODE nodeb = node_vb; assert(nodeb->height==0); { unsigned int i; //printf("{"); for (i=0; iu.l.buffer)); assert(fromto.array[i].b < toku_pma_index_limit(nodeb->u.l.buffer)); } //printf("}\n"); } r = toku_pma_move_indices (nodea->u.l.buffer, nodeb->u.l.buffer, fromto, nodea->rand4fingerprint, &nodea->local_fingerprint, nodeb->rand4fingerprint, &nodeb->local_fingerprint, &nodea->u.l.n_bytes_in_buffer, &nodeb->u.l.n_bytes_in_buffer ); // The bytes in buffer and fingerprint shouldn't change // PMA_ITERATE_IDX(nodeb->u.l.buffer, idx, key, keylen __attribute__((__unused__)), data, datalen __attribute__((__unused__)), // printf("%d: %s %s\n", idx, (char*)key, (char*)data)); VERIFY_COUNTS(nodea); VERIFY_COUNTS(nodeb); nodea->log_lsn = lsn; nodeb->log_lsn = lsn; r = toku_cachetable_unpin(pair->cf, old_diskoff, 1, toku_serialize_brtnode_size(nodea)); assert(r==0); r = toku_cachetable_unpin(pair->cf, new_diskoff, 1, toku_serialize_brtnode_size(nodeb)); assert(r==0); toku_free_INTPAIRARRAY(fromto); } void toku_recover_changeunnamedroot (LSN UU(lsn), FILENUM filenum, DISKOFF UU(oldroot), DISKOFF newroot) { struct cf_pair *pair = NULL; int r = find_cachefile(filenum, &pair); assert(r==0); assert(pair->brt); r = toku_read_and_pin_brt_header(pair->cf, &pair->brt->h); assert(r==0); pair->brt->h->unnamed_root = newroot; r = toku_unpin_brt_header(pair->brt); } void toku_recover_changenamedroot (LSN UU(lsn), FILENUM UU(filenum), BYTESTRING UU(name), DISKOFF UU(oldroot), DISKOFF UU(newroot)) { assert(0); } void toku_recover_changeunusedmemory (LSN UU(lsn), FILENUM filenum, DISKOFF UU(oldunused), DISKOFF newunused) { struct cf_pair *pair = NULL; int r = find_cachefile(filenum, &pair); assert(r==0); assert(pair->brt); r = toku_read_and_pin_brt_header(pair->cf, &pair->brt->h); assert(r==0); pair->brt->h->unused_memory = newunused; r = toku_unpin_brt_header(pair->brt); } static int toku_recover_checkpoint (LSN UU(lsn)) { return 0; } static int toku_recover_xbegin (LSN UU(lsn), TXNID UU(parent)) { return 0; } int tokudb_recover(const char *data_dir, const char *log_dir) { int r; int entrycount=0; char **logfiles; int lockfd; { int namelen=strlen(data_dir); char lockfname[namelen+20]; snprintf(lockfname, sizeof(lockfname), "%s/__recoverylock_dont_delete_me", data_dir); lockfd = open(lockfname, O_RDWR|O_CREAT, S_IRUSR | S_IWUSR); if (lockfd<0) { printf("Couldn't open %s\n", lockfname); return errno; } r=flock(lockfd, LOCK_EX | LOCK_NB); if (r!=0) { printf("Couldn't run recovery because some other process holds the recovery lock %s\n", lockfname); return errno; } } r = toku_logger_find_logfiles(log_dir, &logfiles); if (r!=0) return r; int i; toku_recover_init(); char org_wd[1000]; { char *wd=getcwd(org_wd, sizeof(org_wd)); assert(wd!=0); //printf("%s:%d org_wd=\"%s\"\n", __FILE__, __LINE__, org_wd); } char data_wd[1000]; { r=chdir(data_dir); assert(r==0); char *wd=getcwd(data_wd, sizeof(data_wd)); assert(wd!=0); //printf("%s:%d data_wd=\"%s\"\n", __FILE__, __LINE__, data_wd); } for (i=0; logfiles[i]; i++) { //fprintf(stderr, "Opening %s\n", logfiles[i]); r=chdir(org_wd); assert(r==0); FILE *f = fopen(logfiles[i], "r"); struct log_entry le; u_int32_t version; //printf("Reading file %s\n", logfiles[i]); r=toku_read_and_print_logmagic(f, &version); assert(r==0 && version==0); r=chdir(data_wd); assert(r==0); while ((r = toku_log_fread(f, &le))==0) { //printf("%lld: Got cmd %c\n", (long long)le.u.commit.lsn.lsn, le.cmd); logtype_dispatch_args(&le, toku_recover_); entrycount++; } if (r!=EOF) { if (r==DB_BADFORMAT) { fprintf(stderr, "Bad log format at record %d\n", entrycount); return r; } else { fprintf(stderr, "Huh? %s\n", strerror(r)); return r; } } fclose(f); } toku_recover_cleanup(); for (i=0; logfiles[i]; i++) { toku_free(logfiles[i]); } toku_free(logfiles); r=flock(lockfd, LOCK_UN); if (r!=0) return errno; r=chdir(org_wd); if (r!=0) return errno; //printf("%s:%d recovery successful! ls -l says\n", __FILE__, __LINE__); //system("ls -l"); return 0; }