/* Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved. Copyright (c) 2009, 2020, MariaDB Corporation. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */ /** @file @brief Functions for discover of frm file from handler */ #include "mariadb.h" #include "sql_priv.h" #include "unireg.h" #include "discover.h" #include /** Read the contents of a .frm file. frmdata and len are set to 0 on error. @param name path to table-file "db/name" @param frmdata frm data @param len length of the read frmdata @retval 0 ok @retval 1 Could not open file @retval 2 Could not stat file @retval 3 Could not allocate data for read. Could not read file */ int readfrm(const char *name, const uchar **frmdata, size_t *len) { int error; char index_file[FN_REFLEN]; File file; size_t read_len; uchar *read_data; MY_STAT state; DBUG_ENTER("readfrm"); DBUG_PRINT("enter",("name: '%s'",name)); *frmdata= NULL; // In case of errors *len= 0; error= 1; if ((file= mysql_file_open(key_file_frm, fn_format(index_file, name, "", reg_ext, MY_UNPACK_FILENAME|MY_APPEND_EXT), O_RDONLY | O_SHARE, MYF(0))) < 0) goto err_end; // Get length of file error= 2; if (mysql_file_fstat(file, &state, MYF(0))) goto err; read_len= (size_t)MY_MIN(FRM_MAX_SIZE, state.st_size); // safety // Read whole frm file error= 3; if (!(read_data= (uchar*)my_malloc(key_memory_frm_string, read_len, MYF(MY_WME)))) goto err; if (mysql_file_read(file, read_data, read_len, MYF(MY_NABP))) { my_free(read_data); goto err; } // Setup return data *frmdata= (uchar*) read_data; *len= read_len; error= 0; err: (void) mysql_file_close(file, MYF(MY_WME)); err_end: /* Here when no file */ DBUG_RETURN (error); } /* readfrm */ /* Write the content of a frm data pointer to a frm file. @param path path to table-file "db/name" @param frmdata frm data @param len length of the frmdata @retval 0 ok @retval 2 Could not write file */ int writefrm(const char *path, const char *db, const char *table, bool tmp_table, const uchar *frmdata, size_t len) { char file_name[FN_REFLEN+1]; int error; int create_flags= O_RDWR | O_TRUNC; DBUG_ENTER("writefrm"); DBUG_PRINT("enter",("name: '%s' len: %lu ",path, (ulong) len)); if (tmp_table) create_flags|= O_EXCL | O_NOFOLLOW; strxnmov(file_name, sizeof(file_name)-1, path, reg_ext, NullS); File file= mysql_file_create(key_file_frm, file_name, CREATE_MODE, create_flags, MYF(0)); if (unlikely((error= file < 0))) { if (my_errno == ENOENT) my_error(ER_BAD_DB_ERROR, MYF(0), db); else my_error(ER_CANT_CREATE_TABLE, MYF(0), db, table, my_errno); } else { error= (int)mysql_file_write(file, frmdata, len, MYF(MY_WME | MY_NABP)); if (!error && !tmp_table && opt_sync_frm) error= mysql_file_sync(file, MYF(MY_WME)) || my_sync_dir_by_file(file_name, MYF(MY_WME)); error|= mysql_file_close(file, MYF(MY_WME)); } DBUG_RETURN(error); } /* writefrm */ static inline void advance(FILEINFO* &from, FILEINFO* &to, FILEINFO* cur, bool &skip) { if (skip) // if not copying from= cur; // just advance the start pointer else // if copying if (to == from) // but to the same place (not shifting the data) from= to= cur; // advance both pointers else // otherwise while (from < cur) // have to copy [from...cur) to [to...) *to++ = *from++; skip= false; } /** Go through the directory listing looking for files with a specified extension and add them to the result list @details This function may be called many times on the same directory listing but with different extensions. To avoid discovering the same table twice, whenever a table file is discovered, all files with the same name (independently from the extensions) are removed from the list. Example: the list contained { "db.opt", "t1.MYD", "t1.MYI", "t1.frm", "t2.ARZ", "t3.ARZ", "t3.frm" } on discovering all ".frm" files, tables "t1" and "t3" will be found, and list will become { "db.opt", "t2.ARZ" } and now ".ARZ" discovery can discover the table "t2" @note This function assumes that the directory listing is sorted alphabetically. @note Partitioning makes this more complicated. A partitioned table t1 might have files, like t1.frm, t1#P#part1.ibd, t1#P#foo.ibd, etc. That means we need to compare file names only up to the first '#' or '.' whichever comes first. */ int extension_based_table_discovery(MY_DIR *dirp, const char *ext_meta, handlerton::discovered_list *result) { CHARSET_INFO *cs= character_set_filesystem; size_t ext_meta_len= strlen(ext_meta); FILEINFO *from, *to, *cur, *end; bool skip= false; from= to= cur= dirp->dir_entry; end= cur + dirp->number_of_files; while (cur < end) { char *octothorp= strchr(cur->name + 1, '#'); char *ext= strchr(octothorp ? octothorp : cur->name, FN_EXTCHAR); if (ext) { size_t len= (octothorp ? octothorp : ext) - cur->name; if (from != cur && (strlen(from->name) <= len || cs->strnncoll(from->name, len, cur->name, len) || (from->name[len] != FN_EXTCHAR && from->name[len] != '#'))) advance(from, to, cur, skip); if (cs->strnncoll(ext, strlen(ext), ext_meta, ext_meta_len) == 0) { *ext = 0; if (result->add_file(cur->name)) return 1; *ext = FN_EXTCHAR; skip= true; // table discovered, skip all files with the same name } } else { advance(from, to, cur, skip); from++; } cur++; } advance(from, to, cur, skip); dirp->number_of_files= (uint)(to - dirp->dir_entry); return 0; } /** Simple, not reusable file-based table discovery @details simplified version of extension_based_table_discovery(), that does not modify the list of files. It cannot be called many times for the same directory listing, otherwise it'll produce duplicate results. */ int ext_table_discovery_simple(MY_DIR *dirp, handlerton::discovered_list *result) { CHARSET_INFO *cs= character_set_filesystem; FILEINFO *cur, *end; cur= dirp->dir_entry; end= cur + dirp->number_of_files; while (cur < end) { char *ext= strrchr(cur->name, FN_EXTCHAR); if (ext) { if (cs->strnncoll(ext, strlen(ext), reg_ext, reg_ext_length) == 0) { *ext = 0; if (result->add_file(cur->name)) return 1; } } cur++; } return 0; }