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Diffstat (limited to '')
| -rw-r--r-- | sql/datadict.cc | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/sql/datadict.cc b/sql/datadict.cc new file mode 100644 index 00000000..e09eee98 --- /dev/null +++ b/sql/datadict.cc @@ -0,0 +1,199 @@ +/* Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved. + + 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 */ + +#include "mariadb.h" +#include "datadict.h" +#include "sql_priv.h" +#include "sql_class.h" +#include "sql_table.h" +#include "ha_sequence.h" + +static int read_string(File file, uchar**to, size_t length) +{ + DBUG_ENTER("read_string"); + + /* This can't use MY_THREAD_SPECIFIC as it's used on server start */ + if (!(*to= (uchar*) my_malloc(PSI_INSTRUMENT_ME, length+1,MYF(MY_WME))) || + mysql_file_read(file, *to, length, MYF(MY_NABP))) + { + my_free(*to); + *to= 0; + DBUG_RETURN(1); + } + *((char*) *to+length)= '\0'; // C-style safety + DBUG_RETURN (0); +} + + +/** + Check type of .frm if we are not going to parse it. + + @param[in] thd The current session. + @param[in] path path to FRM file. + @param[in/out] engine_name table engine name (length < NAME_CHAR_LEN) + + engine_name is a LEX_CSTRING, where engine_name->str must point to + a buffer of at least NAME_CHAR_LEN+1 bytes. + If engine_name is 0, then the function will only test if the file is a + view or not + + @retval TABLE_TYPE_UNKNOWN error - file can't be opened + @retval TABLE_TYPE_NORMAL table + @retval TABLE_TYPE_SEQUENCE sequence table + @retval TABLE_TYPE_VIEW view +*/ + +Table_type dd_frm_type(THD *thd, char *path, LEX_CSTRING *engine_name) +{ + File file; + uchar header[40]; //"TYPE=VIEW\n" it is 10 characters + size_t error; + Table_type type= TABLE_TYPE_UNKNOWN; + uchar dbt; + DBUG_ENTER("dd_frm_type"); + + file= mysql_file_open(key_file_frm, path, O_RDONLY | O_SHARE, MYF(0)); + if (file < 0) + DBUG_RETURN(TABLE_TYPE_UNKNOWN); + + /* + We return TABLE_TYPE_NORMAL if we can open the .frm file. This allows us + to drop a bad .frm file with DROP TABLE + */ + type= TABLE_TYPE_NORMAL; + + /* + Initialize engine name in case we are not able to find it out + The cast is safe, as engine_name->str points to a usable buffer. + */ + if (engine_name) + { + engine_name->length= 0; + ((char*) (engine_name->str))[0]= 0; + } + + if (unlikely((error= mysql_file_read(file, (uchar*) header, sizeof(header), MYF(MY_NABP))))) + goto err; + + if (unlikely((!strncmp((char*) header, "TYPE=VIEW\n", 10)))) + { + type= TABLE_TYPE_VIEW; + goto err; + } + + /* engine_name is 0 if we only want to know if table is view or not */ + if (!engine_name) + goto err; + + if (!is_binary_frm_header(header)) + goto err; + + dbt= header[3]; + + if (((header[39] >> 4) & 3) == HA_CHOICE_YES) + { + DBUG_PRINT("info", ("Sequence found")); + type= TABLE_TYPE_SEQUENCE; + } + + /* cannot use ha_resolve_by_legacy_type without a THD */ + if (thd && dbt < DB_TYPE_FIRST_DYNAMIC) + { + handlerton *ht= ha_resolve_by_legacy_type(thd, (enum legacy_db_type)dbt); + if (ht) + { + *engine_name= hton2plugin[ht->slot]->name; + goto err; + } + } + + /* read the true engine name */ + { + MY_STAT state; + uchar *frm_image= 0; + uint n_length; + + if (mysql_file_fstat(file, &state, MYF(MY_WME))) + goto err; + + if (mysql_file_seek(file, 0, SEEK_SET, MYF(MY_WME))) + goto err; + + if (read_string(file, &frm_image, (size_t)state.st_size)) + goto err; + + if ((n_length= uint4korr(frm_image+55))) + { + uint record_offset= uint2korr(frm_image+6)+ + ((uint2korr(frm_image+14) == 0xffff ? + uint4korr(frm_image+47) : uint2korr(frm_image+14))); + uint reclength= uint2korr(frm_image+16); + + uchar *next_chunk= frm_image + record_offset + reclength; + uchar *buff_end= next_chunk + n_length; + uint connect_string_length= uint2korr(next_chunk); + next_chunk+= connect_string_length + 2; + if (next_chunk + 2 < buff_end) + { + uint len= uint2korr(next_chunk); + if (len <= NAME_CHAR_LEN) + { + /* + The following cast is safe as the caller has allocated buffer + and it's up to this function to generate the name. + */ + strmake((char*) engine_name->str, (char*)next_chunk + 2, + engine_name->length= len); + } + } + } + + my_free(frm_image); + } + + /* Probably a table. */ +err: + mysql_file_close(file, MYF(MY_WME)); + DBUG_RETURN(type); +} + + +/* + Regenerate a metadata locked table. + + @param thd Thread context. + @param db Name of the database to which the table belongs to. + @param name Table name. + + @retval FALSE Success. + @retval TRUE Error. +*/ + +bool dd_recreate_table(THD *thd, const char *db, const char *table_name) +{ + HA_CREATE_INFO create_info; + char path_buf[FN_REFLEN + 1]; + DBUG_ENTER("dd_recreate_table"); + + /* There should be a exclusive metadata lock on the table. */ + DBUG_ASSERT(thd->mdl_context.is_lock_owner(MDL_key::TABLE, db, table_name, + MDL_EXCLUSIVE)); + create_info.init(); + build_table_filename(path_buf, sizeof(path_buf) - 1, + db, table_name, "", 0); + /* Attempt to reconstruct the table. */ + DBUG_RETURN(ha_create_table(thd, path_buf, db, table_name, &create_info, 0)); +} + |