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Diffstat (limited to 'sql/ha_federated.cc')
| -rw-r--r-- | sql/ha_federated.cc | 2961 |
1 files changed, 0 insertions, 2961 deletions
diff --git a/sql/ha_federated.cc b/sql/ha_federated.cc deleted file mode 100644 index 6944dc5a030..00000000000 --- a/sql/ha_federated.cc +++ /dev/null @@ -1,2961 +0,0 @@ -/* Copyright (C) 2004 MySQL AB - - 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ - -/* - - MySQL Federated Storage Engine - - ha_federated.cc - MySQL Federated Storage Engine - Patrick Galbraith and Brian Aker, 2004 - - This is a handler which uses a foreign database as the data file, as - opposed to a handler like MyISAM, which uses .MYD files locally. - - How this handler works - ---------------------------------- - Normal database files are local and as such: You create a table called - 'users', a file such as 'users.MYD' is created. A handler reads, inserts, - deletes, updates data in this file. The data is stored in particular format, - so to read, that data has to be parsed into fields, to write, fields have to - be stored in this format to write to this data file. - - With MySQL Federated storage engine, there will be no local files - for each table's data (such as .MYD). A foreign database will store - the data that would normally be in this file. This will necessitate - the use of MySQL client API to read, delete, update, insert this - data. The data will have to be retrieve via an SQL call "SELECT * - FROM users". Then, to read this data, it will have to be retrieved - via mysql_fetch_row one row at a time, then converted from the - column in this select into the format that the handler expects. - - The create table will simply create the .frm file, and within the - "CREATE TABLE" SQL, there SHALL be any of the following : - - comment=scheme://username:password@hostname:port/database/tablename - comment=scheme://username@hostname/database/tablename - comment=scheme://username:password@hostname/database/tablename - comment=scheme://username:password@hostname/database/tablename - - An example would be: - - comment=mysql://username:password@hostname:port/database/tablename - - ***IMPORTANT*** - - This is a first release, conceptual release - Only 'mysql://' is supported at this release. - - - This comment connection string is necessary for the handler to be - able to connect to the foreign server. - - - The basic flow is this: - - SQL calls issues locally -> - mysql handler API (data in handler format) -> - mysql client API (data converted to SQL calls) -> - foreign database -> mysql client API -> - convert result sets (if any) to handler format -> - handler API -> results or rows affected to local - - What this handler does and doesn't support - ------------------------------------------ - * Tables MUST be created on the foreign server prior to any action on those - tables via the handler, first version. IMPORTANT: IF you MUST use the - federated storage engine type on the REMOTE end, MAKE SURE [ :) ] That - the table you connect to IS NOT a table pointing BACK to your ORIGNAL - table! You know and have heard the screaching of audio feedback? You - know putting two mirror in front of each other how the reflection - continues for eternity? Well, need I say more?! - * There will not be support for transactions. - * There is no way for the handler to know if the foreign database or table - has changed. The reason for this is that this database has to work like a - data file that would never be written to by anything other than the - database. The integrity of the data in the local table could be breached - if there was any change to the foreign database. - * Support for SELECT, INSERT, UPDATE , DELETE, indexes. - * No ALTER TABLE, DROP TABLE or any other Data Definition Language calls. - * Prepared statements will not be used in the first implementation, it - remains to to be seen whether the limited subset of the client API for the - server supports this. - * This uses SELECT, INSERT, UPDATE, DELETE and not HANDLER for its - implementation. - * This will not work with the query cache. - - Method calls - - A two column table, with one record: - - (SELECT) - - "SELECT * FROM foo" - ha_federated::info - ha_federated::scan_time: - ha_federated::rnd_init: share->select_query SELECT * FROM foo - ha_federated::extra - - <for every row of data retrieved> - ha_federated::rnd_next - ha_federated::convert_row_to_internal_format - ha_federated::rnd_next - </for every row of data retrieved> - - ha_federated::rnd_end - ha_federated::extra - ha_federated::reset - - (INSERT) - - "INSERT INTO foo (id, ts) VALUES (2, now());" - - ha_federated::write_row - - ha_federated::reset - - (UPDATE) - - "UPDATE foo SET ts = now() WHERE id = 1;" - - ha_federated::index_init - ha_federated::index_read - ha_federated::index_read_idx - ha_federated::rnd_next - ha_federated::convert_row_to_internal_format - ha_federated::update_row - - ha_federated::extra - ha_federated::extra - ha_federated::extra - ha_federated::external_lock - ha_federated::reset - - - How do I use this handler? - -------------------------- - First of all, you need to build this storage engine: - - ./configure --with-federated-storage-engine - make - - Next, to use this handler, it's very simple. You must - have two databases running, either both on the same host, or - on different hosts. - - One the server that will be connecting to the foreign - host (client), you create your table as such: - - CREATE TABLE test_table ( - id int(20) NOT NULL auto_increment, - name varchar(32) NOT NULL default '', - other int(20) NOT NULL default '0', - PRIMARY KEY (id), - KEY name (name), - KEY other_key (other)) - ENGINE="FEDERATED" - DEFAULT CHARSET=latin1 - COMMENT='root@127.0.0.1:9306/federated/test_federated'; - - Notice the "COMMENT" and "ENGINE" field? This is where you - respectively set the engine type, "FEDERATED" and foreign - host information, this being the database your 'client' database - will connect to and use as the "data file". Obviously, the foreign - database is running on port 9306, so you want to start up your other - database so that it is indeed on port 9306, and your federated - database on a port other than that. In my setup, I use port 5554 - for federated, and port 5555 for the foreign database. - - Then, on the foreign database: - - CREATE TABLE test_table ( - id int(20) NOT NULL auto_increment, - name varchar(32) NOT NULL default '', - other int(20) NOT NULL default '0', - PRIMARY KEY (id), - KEY name (name), - KEY other_key (other)) - ENGINE="<NAME>" <-- whatever you want, or not specify - DEFAULT CHARSET=latin1 ; - - This table is exactly the same (and must be exactly the same), - except that it is not using the federated handler and does - not need the URL. - - - How to see the handler in action - -------------------------------- - - When developing this handler, I compiled the federated database with - debugging: - - ./configure --with-federated-storage-engine - --prefix=/home/mysql/mysql-build/federated/ --with-debug - - Once compiled, I did a 'make install' (not for the purpose of installing - the binary, but to install all the files the binary expects to see in the - diretory I specified in the build with --prefix, - "/home/mysql/mysql-build/federated". - - Then, I started the foreign server: - - /usr/local/mysql/bin/mysqld_safe - --user=mysql --log=/tmp/mysqld.5555.log -P 5555 - - Then, I went back to the directory containing the newly compiled mysqld, - <builddir>/sql/, started up gdb: - - gdb ./mysqld - - Then, withn the (gdb) prompt: - (gdb) run --gdb --port=5554 --socket=/tmp/mysqld.5554 --skip-innodb --debug - - Next, I open several windows for each: - - 1. Tail the debug trace: tail -f /tmp/mysqld.trace|grep ha_fed - 2. Tail the SQL calls to the foreign database: tail -f /tmp/mysqld.5555.log - 3. A window with a client open to the federated server on port 5554 - 4. A window with a client open to the federated server on port 5555 - - I would create a table on the client to the foreign server on port - 5555, and then to the federated server on port 5554. At this point, - I would run whatever queries I wanted to on the federated server, - just always remembering that whatever changes I wanted to make on - the table, or if I created new tables, that I would have to do that - on the foreign server. - - Another thing to look for is 'show variables' to show you that you have - support for federated handler support: - - show variables like '%federat%' - - and: - - show storage engines; - - Both should display the federated storage handler. - - - Testing - ------- - - There is a test for MySQL Federated Storage Handler in ./mysql-test/t, - federatedd.test It starts both a slave and master database using - the same setup that the replication tests use, with the exception that - it turns off replication, and sets replication to ignore the test tables. - After ensuring that you actually do have support for the federated storage - handler, numerous queries/inserts/updates/deletes are run, many derived - from the MyISAM tests, plus som other tests which were meant to reveal - any issues that would be most likely to affect this handler. All tests - should work! ;) - - To run these tests, go into ./mysql-test (based in the directory you - built the server in) - - ./mysql-test-run federatedd - - To run the test, or if you want to run the test and have debug info: - - ./mysql-test-run --debug federated - - This will run the test in debug mode, and you can view the trace and - log files in the ./mysql-test/var/log directory - - ls -l mysql-test/var/log/ - -rw-r--r-- 1 patg patg 17 4 Dec 12:27 current_test - -rw-r--r-- 1 patg patg 692 4 Dec 12:52 manager.log - -rw-rw---- 1 patg patg 21246 4 Dec 12:51 master-bin.000001 - -rw-rw---- 1 patg patg 68 4 Dec 12:28 master-bin.index - -rw-r--r-- 1 patg patg 1620 4 Dec 12:51 master.err - -rw-rw---- 1 patg patg 23179 4 Dec 12:51 master.log - -rw-rw---- 1 patg patg 16696550 4 Dec 12:51 master.trace - -rw-r--r-- 1 patg patg 0 4 Dec 12:28 mysqltest-time - -rw-r--r-- 1 patg patg 2024051 4 Dec 12:51 mysqltest.trace - -rw-rw---- 1 patg patg 94992 4 Dec 12:51 slave-bin.000001 - -rw-rw---- 1 patg patg 67 4 Dec 12:28 slave-bin.index - -rw-rw---- 1 patg patg 249 4 Dec 12:52 slave-relay-bin.000003 - -rw-rw---- 1 patg patg 73 4 Dec 12:28 slave-relay-bin.index - -rw-r--r-- 1 patg patg 1349 4 Dec 12:51 slave.err - -rw-rw---- 1 patg patg 96206 4 Dec 12:52 slave.log - -rw-rw---- 1 patg patg 15706355 4 Dec 12:51 slave.trace - -rw-r--r-- 1 patg patg 0 4 Dec 12:51 warnings - - Of course, again, you can tail the trace log: - - tail -f mysql-test/var/log/master.trace |grep ha_fed - - As well as the slave query log: - - tail -f mysql-test/var/log/slave.log - - Files that comprise the test suit - --------------------------------- - mysql-test/t/federated.test - mysql-test/r/federated.result - mysql-test/r/have_federated_db.require - mysql-test/include/have_federated_db.inc - - - Other tidbits - ------------- - - These were the files that were modified or created for this - Federated handler to work: - - ./configure.in - ./sql/Makefile.am - ./config/ac_macros/ha_federated.m4 - ./sql/handler.cc - ./sql/mysqld.cc - ./sql/set_var.cc - ./sql/field.h - ./sql/sql_string.h - ./mysql-test/mysql-test-run(.sh) - ./mysql-test/t/federated.test - ./mysql-test/r/federated.result - ./mysql-test/r/have_federated_db.require - ./mysql-test/include/have_federated_db.inc - ./sql/ha_federated.cc - ./sql/ha_federated.h - -*/ - - -#include "mysql_priv.h" -#ifdef USE_PRAGMA_IMPLEMENTATION -#pragma implementation // gcc: Class implementation -#endif - -#ifdef HAVE_FEDERATED_DB -#include "ha_federated.h" - -#include "m_string.h" -/* Variables for federated share methods */ -static HASH federated_open_tables; // Hash used to track open - // tables -pthread_mutex_t federated_mutex; // This is the mutex we use to - // init the hash -static int federated_init= FALSE; // Variable for checking the - // init state of hash -static char ident_quote_char= '`'; // Character for quoting - // identifiers -static char value_quote_char= '\''; // Character for quoting - // literals -static const int bulk_padding= 64; // bytes "overhead" in packet - -/* Federated storage engine handlerton */ - -handlerton federated_hton= { - "FEDERATED", - SHOW_OPTION_YES, - "Federated MySQL storage engine", - DB_TYPE_FEDERATED_DB, - federated_db_init, - 0, /* slot */ - 0, /* savepoint size. */ - NULL, /* close_connection */ - NULL, /* savepoint */ - NULL, /* rollback to savepoint */ - NULL, /* release savepoint */ - NULL, /* commit */ - NULL, /* rollback */ - NULL, /* prepare */ - NULL, /* recover */ - NULL, /* commit_by_xid */ - NULL, /* rollback_by_xid */ - NULL, /* create_cursor_read_view */ - NULL, /* set_cursor_read_view */ - NULL, /* close_cursor_read_view */ - HTON_ALTER_NOT_SUPPORTED -}; - - -/* Function we use in the creation of our hash to get key. */ - -static byte *federated_get_key(FEDERATED_SHARE *share, uint *length, - my_bool not_used __attribute__ ((unused))) -{ - *length= share->connect_string_length; - return (byte*) share->scheme; -} - -/* - Initialize the federated handler. - - SYNOPSIS - federated_db_init() - void - - RETURN - FALSE OK - TRUE Error -*/ - -bool federated_db_init() -{ - DBUG_ENTER("federated_db_init"); - /* the federated engine can be disabled by a command line option */ - if (have_federated_db == SHOW_OPTION_DISABLED) - DBUG_RETURN(TRUE); - if (pthread_mutex_init(&federated_mutex, MY_MUTEX_INIT_FAST)) - goto error; - if (hash_init(&federated_open_tables, &my_charset_bin, 32, 0, 0, - (hash_get_key) federated_get_key, 0, 0)) - { - VOID(pthread_mutex_destroy(&federated_mutex)); - } - else - { - federated_init= TRUE; - DBUG_RETURN(FALSE); - } -error: - have_federated_db= SHOW_OPTION_DISABLED; // If we couldn't use handler - DBUG_RETURN(TRUE); -} - - -/* - Release the federated handler. - - SYNOPSIS - federated_db_end() - void - - RETURN - FALSE OK -*/ - -bool federated_db_end() -{ - if (federated_init) - { - hash_free(&federated_open_tables); - VOID(pthread_mutex_destroy(&federated_mutex)); - } - federated_init= 0; - return FALSE; -} - - -/** - @brief Append identifiers to the string. - - @param[in,out] string The target string. - @param[in] name Identifier name - @param[in] length Length of identifier name in bytes - @param[in] quote_char Quote char to use for quoting identifier. - - @return Operation Status - @retval FALSE OK - @retval TRUE There was an error appending to the string. - - @note This function is based upon the append_identifier() function - in sql_show.cc except that quoting always occurs. -*/ - -static bool append_ident(String *string, const char *name, uint length, - const char quote_char) -{ - bool result; - uint clen; - const char *name_end; - DBUG_ENTER("append_ident"); - - if (quote_char) - { - string->reserve(length * 2 + 2); - if ((result= string->append("e_char, 1, system_charset_info))) - goto err; - - for (name_end= name+length; name < name_end; name+= clen) - { - uchar c= *(uchar *) name; - if (!(clen= my_mbcharlen(system_charset_info, c))) - clen= 1; - if (clen == 1 && c == (uchar) quote_char && - (result= string->append("e_char, 1, system_charset_info))) - goto err; - if ((result= string->append(name, clen, string->charset()))) - goto err; - } - result= string->append("e_char, 1, system_charset_info); - } - else - result= string->append(name, length, system_charset_info); - -err: - DBUG_RETURN(result); -} - - -static int parse_url_error(FEDERATED_SHARE *share, TABLE *table, int error_num) -{ - char buf[FEDERATED_QUERY_BUFFER_SIZE]; - int buf_len; - DBUG_ENTER("ha_federated parse_url_error"); - - if (share->scheme) - { - DBUG_PRINT("info", - ("error: parse_url. Returning error code %d freeing share->scheme 0x%lx", - error_num, (long) share->scheme)); - my_free((gptr) share->scheme, MYF(0)); - share->scheme= 0; - } - buf_len= min(table->s->connect_string.length, - FEDERATED_QUERY_BUFFER_SIZE-1); - strmake(buf, table->s->connect_string.str, buf_len); - my_error(error_num, MYF(0), buf); - DBUG_RETURN(error_num); -} - -/* - Parse connection info from table->s->connect_string - - SYNOPSIS - parse_url() - share pointer to FEDERATED share - table pointer to current TABLE class - table_create_flag determines what error to throw - - DESCRIPTION - populates the share with information about the connection - to the foreign database that will serve as the data source. - This string must be specified (currently) in the "comment" field, - listed in the CREATE TABLE statement. - - This string MUST be in the format of any of these: - - scheme://username:password@hostname:port/database/table - scheme://username@hostname/database/table - scheme://username@hostname:port/database/table - scheme://username:password@hostname/database/table - - An Example: - - mysql://joe:joespass@192.168.1.111:9308/federated/testtable - - ***IMPORTANT*** - Currently, only "mysql://" is supported. - - 'password' and 'port' are both optional. - - RETURN VALUE - 0 success - error_num particular error code - -*/ - -static int parse_url(FEDERATED_SHARE *share, TABLE *table, - uint table_create_flag) -{ - uint error_num= (table_create_flag ? - ER_FOREIGN_DATA_STRING_INVALID_CANT_CREATE : - ER_FOREIGN_DATA_STRING_INVALID); - DBUG_ENTER("ha_federated::parse_url"); - - share->port= 0; - share->socket= 0; - DBUG_PRINT("info", ("Length %d \n", table->s->connect_string.length)); - DBUG_PRINT("info", ("String %.*s \n", table->s->connect_string.length, - table->s->connect_string.str)); - share->scheme= my_strdup_with_length(table->s->connect_string.str, - table->s->connect_string.length, - MYF(0)); - - share->connect_string_length= table->s->connect_string.length; - DBUG_PRINT("info",("parse_url alloced share->scheme 0x%lx", (long) share->scheme)); - - /* - remove addition of null terminator and store length - for each string in share - */ - if (!(share->username= strstr(share->scheme, "://"))) - goto error; - share->scheme[share->username - share->scheme]= '\0'; - - if (strcmp(share->scheme, "mysql") != 0) - goto error; - - share->username+= 3; - - if (!(share->hostname= strchr(share->username, '@'))) - goto error; - - share->username[share->hostname - share->username]= '\0'; - share->hostname++; - - if ((share->password= strchr(share->username, ':'))) - { - share->username[share->password - share->username]= '\0'; - share->password++; - share->username= share->username; - /* make sure there isn't an extra / or @ */ - if ((strchr(share->password, '/') || strchr(share->hostname, '@'))) - goto error; - /* - Found that if the string is: - user:@hostname:port/database/table - Then password is a null string, so set to NULL - */ - if ((share->password[0] == '\0')) - share->password= NULL; - } - else - share->username= share->username; - - /* make sure there isn't an extra / or @ */ - if ((strchr(share->username, '/')) || (strchr(share->hostname, '@'))) - goto error; - - if (!(share->database= strchr(share->hostname, '/'))) - goto error; - share->hostname[share->database - share->hostname]= '\0'; - share->database++; - - if ((share->sport= strchr(share->hostname, ':'))) - { - share->hostname[share->sport - share->hostname]= '\0'; - share->sport++; - if (share->sport[0] == '\0') - share->sport= NULL; - else - share->port= atoi(share->sport); - } - - if (!(share->table_name= strchr(share->database, '/'))) - goto error; - share->database[share->table_name - share->database]= '\0'; - share->table_name++; - - share->table_name_length= (uint) strlen(share->table_name); - - /* make sure there's not an extra / */ - if ((strchr(share->table_name, '/'))) - goto error; - - /* - If hostname is omitted, we set it to NULL. According to - mysql_real_connect() manual: - The value of host may be either a hostname or an IP address. - If host is NULL or the string "localhost", a connection to the - local host is assumed. - */ - if (share->hostname[0] == '\0') - share->hostname= NULL; - - if (!share->port) - { - if (!share->hostname || strcmp(share->hostname, my_localhost) == 0) - share->socket= (char*) MYSQL_UNIX_ADDR; - else - share->port= MYSQL_PORT; - } - - DBUG_PRINT("info", - ("scheme %s username %s password %s \ - hostname %s port %d database %s tablename %s\n", - share->scheme, share->username, share->password, - share->hostname, share->port, share->database, - share->table_name)); - - DBUG_RETURN(0); - -error: - DBUG_RETURN(parse_url_error(share, table, error_num)); -} - - -/***************************************************************************** -** FEDERATED tables -*****************************************************************************/ - -ha_federated::ha_federated(TABLE *table_arg) - :handler(&federated_hton, table_arg), - mysql(0), stored_result(0) -{ - bzero(&bulk_insert, sizeof(bulk_insert)); -} - - -/* - Convert MySQL result set row to handler internal format - - SYNOPSIS - convert_row_to_internal_format() - record Byte pointer to record - row MySQL result set row from fetchrow() - result Result set to use - - DESCRIPTION - This method simply iterates through a row returned via fetchrow with - values from a successful SELECT , and then stores each column's value - in the field object via the field object pointer (pointing to the table's - array of field object pointers). This is how the handler needs the data - to be stored to then return results back to the user - - RETURN VALUE - 0 After fields have had field values stored from record - */ - -uint ha_federated::convert_row_to_internal_format(byte *record, - MYSQL_ROW row, - MYSQL_RES *result) -{ - ulong *lengths; - Field **field; - DBUG_ENTER("ha_federated::convert_row_to_internal_format"); - - lengths= mysql_fetch_lengths(result); - - for (field= table->field; *field; field++) - { - /* - index variable to move us through the row at the - same iterative step as the field - */ - size_t x= (field - table->field); - my_ptrdiff_t old_ptr; - old_ptr= (my_ptrdiff_t) (record - table->record[0]); - (*field)->move_field(old_ptr); - if (!row[x]) - { - (*field)->set_null(); - (*field)->reset(); - } - else - { - (*field)->set_notnull(); - (*field)->store(row[x], lengths[x], &my_charset_bin); - } - (*field)->move_field(-old_ptr); - } - - DBUG_RETURN(0); -} - -static bool emit_key_part_name(String *to, KEY_PART_INFO *part) -{ - DBUG_ENTER("emit_key_part_name"); - if (append_ident(to, part->field->field_name, - (uint) strlen(part->field->field_name), ident_quote_char)) - DBUG_RETURN(1); // Out of memory - DBUG_RETURN(0); -} - -static bool emit_key_part_element(String *to, KEY_PART_INFO *part, - bool needs_quotes, bool is_like, - const byte *ptr, uint len) -{ - Field *field= part->field; - DBUG_ENTER("emit_key_part_element"); - - if (needs_quotes && to->append(FEDERATED_SQUOTE)) - DBUG_RETURN(1); - - if (part->type == HA_KEYTYPE_BIT) - { - char buff[STRING_BUFFER_USUAL_SIZE], *buf= buff; - - *buf++= '0'; - *buf++= 'x'; - buf= octet2hex(buf, (char*) ptr, len); - if (to->append((char*) buff, (uint)(buf - buff))) - DBUG_RETURN(1); - } - else if (part->key_part_flag & HA_BLOB_PART) - { - String blob; - uint blob_length= uint2korr(ptr); - blob.set_quick((char*) ptr+HA_KEY_BLOB_LENGTH, - blob_length, &my_charset_bin); - if (append_escaped(to, &blob)) - DBUG_RETURN(1); - } - else if (part->key_part_flag & HA_VAR_LENGTH_PART) - { - String varchar; - uint var_length= uint2korr(ptr); - varchar.set_quick((char*) ptr+HA_KEY_BLOB_LENGTH, - var_length, &my_charset_bin); - if (append_escaped(to, &varchar)) - DBUG_RETURN(1); - } - else - { - char strbuff[MAX_FIELD_WIDTH]; - String str(strbuff, sizeof(strbuff), part->field->charset()), *res; - - res= field->val_str(&str, (char *)ptr); - - if (field->result_type() == STRING_RESULT) - { - if (append_escaped(to, res)) - DBUG_RETURN(1); - } - else if (to->append(res->ptr(), res->length())) - DBUG_RETURN(1); - } - - if (is_like && to->append(FEDERATED_PERCENT)) - DBUG_RETURN(1); - - if (needs_quotes && to->append(FEDERATED_SQUOTE)) - DBUG_RETURN(1); - - DBUG_RETURN(0); -} - -/* - Create a WHERE clause based off of values in keys - Note: This code was inspired by key_copy from key.cc - - SYNOPSIS - create_where_from_key () - to String object to store WHERE clause - key_info KEY struct pointer - key byte pointer containing key - key_length length of key - range_type 0 - no range, 1 - min range, 2 - max range - (see enum range_operation) - - DESCRIPTION - Using iteration through all the keys via a KEY_PART_INFO pointer, - This method 'extracts' the value of each key in the byte pointer - *key, and for each key found, constructs an appropriate WHERE clause - - RETURN VALUE - 0 After all keys have been accounted for to create the WHERE clause - 1 No keys found - - Range flags Table per Timour: - - ----------------- - - start_key: - * ">" -> HA_READ_AFTER_KEY - * ">=" -> HA_READ_KEY_OR_NEXT - * "=" -> HA_READ_KEY_EXACT - - - end_key: - * "<" -> HA_READ_BEFORE_KEY - * "<=" -> HA_READ_AFTER_KEY - - records_in_range: - ----------------- - - start_key: - * ">" -> HA_READ_AFTER_KEY - * ">=" -> HA_READ_KEY_EXACT - * "=" -> HA_READ_KEY_EXACT - - - end_key: - * "<" -> HA_READ_BEFORE_KEY - * "<=" -> HA_READ_AFTER_KEY - * "=" -> HA_READ_AFTER_KEY - -0 HA_READ_KEY_EXACT, Find first record else error -1 HA_READ_KEY_OR_NEXT, Record or next record -2 HA_READ_KEY_OR_PREV, Record or previous -3 HA_READ_AFTER_KEY, Find next rec. after key-record -4 HA_READ_BEFORE_KEY, Find next rec. before key-record -5 HA_READ_PREFIX, Key which as same prefix -6 HA_READ_PREFIX_LAST, Last key with the same prefix -7 HA_READ_PREFIX_LAST_OR_PREV, Last or prev key with the same prefix - -Flags that I've found: - -id, primary key, varchar - -id = 'ccccc' -records_in_range: start_key 0 end_key 3 -read_range_first: start_key 0 end_key NULL - -id > 'ccccc' -records_in_range: start_key 3 end_key NULL -read_range_first: start_key 3 end_key NULL - -id < 'ccccc' -records_in_range: start_key NULL end_key 4 -read_range_first: start_key NULL end_key 4 - -id <= 'ccccc' -records_in_range: start_key NULL end_key 3 -read_range_first: start_key NULL end_key 3 - -id >= 'ccccc' -records_in_range: start_key 0 end_key NULL -read_range_first: start_key 1 end_key NULL - -id like 'cc%cc' -records_in_range: start_key 0 end_key 3 -read_range_first: start_key 1 end_key 3 - -id > 'aaaaa' and id < 'ccccc' -records_in_range: start_key 3 end_key 4 -read_range_first: start_key 3 end_key 4 - -id >= 'aaaaa' and id < 'ccccc'; -records_in_range: start_key 0 end_key 4 -read_range_first: start_key 1 end_key 4 - -id >= 'aaaaa' and id <= 'ccccc'; -records_in_range: start_key 0 end_key 3 -read_range_first: start_key 1 end_key 3 - -id > 'aaaaa' and id <= 'ccccc'; -records_in_range: start_key 3 end_key 3 -read_range_first: start_key 3 end_key 3 - -numeric keys: - -id = 4 -index_read_idx: start_key 0 end_key NULL - -id > 4 -records_in_range: start_key 3 end_key NULL -read_range_first: start_key 3 end_key NULL - -id >= 4 -records_in_range: start_key 0 end_key NULL -read_range_first: start_key 1 end_key NULL - -id < 4 -records_in_range: start_key NULL end_key 4 -read_range_first: start_key NULL end_key 4 - -id <= 4 -records_in_range: start_key NULL end_key 3 -read_range_first: start_key NULL end_key 3 - -id like 4 -full table scan, select * from - -id > 2 and id < 8 -records_in_range: start_key 3 end_key 4 -read_range_first: start_key 3 end_key 4 - -id >= 2 and id < 8 -records_in_range: start_key 0 end_key 4 -read_range_first: start_key 1 end_key 4 - -id >= 2 and id <= 8 -records_in_range: start_key 0 end_key 3 -read_range_first: start_key 1 end_key 3 - -id > 2 and id <= 8 -records_in_range: start_key 3 end_key 3 -read_range_first: start_key 3 end_key 3 - -multi keys (id int, name varchar, other varchar) - -id = 1; -records_in_range: start_key 0 end_key 3 -read_range_first: start_key 0 end_key NULL - -id > 4; -id > 2 and name = '333'; remote: id > 2 -id > 2 and name > '333'; remote: id > 2 -id > 2 and name > '333' and other < 'ddd'; remote: id > 2 no results -id > 2 and name >= '333' and other < 'ddd'; remote: id > 2 1 result -id >= 4 and name = 'eric was here' and other > 'eeee'; -records_in_range: start_key 3 end_key NULL -read_range_first: start_key 3 end_key NULL - -id >= 4; -id >= 2 and name = '333' and other < 'ddd'; -remote: `id` >= 2 AND `name` >= '333'; -records_in_range: start_key 0 end_key NULL -read_range_first: start_key 1 end_key NULL - -id < 4; -id < 3 and name = '222' and other <= 'ccc'; remote: id < 3 -records_in_range: start_key NULL end_key 4 -read_range_first: start_key NULL end_key 4 - -id <= 4; -records_in_range: start_key NULL end_key 3 -read_range_first: start_key NULL end_key 3 - -id like 4; -full table scan - -id > 2 and id < 4; -records_in_range: start_key 3 end_key 4 -read_range_first: start_key 3 end_key 4 - -id >= 2 and id < 4; -records_in_range: start_key 0 end_key 4 -read_range_first: start_key 1 end_key 4 - -id >= 2 and id <= 4; -records_in_range: start_key 0 end_key 3 -read_range_first: start_key 1 end_key 3 - -id > 2 and id <= 4; -id = 6 and name = 'eric was here' and other > 'eeee'; -remote: (`id` > 6 AND `name` > 'eric was here' AND `other` > 'eeee') -AND (`id` <= 6) AND ( AND `name` <= 'eric was here') -no results -records_in_range: start_key 3 end_key 3 -read_range_first: start_key 3 end_key 3 - -Summary: - -* If the start key flag is 0 the max key flag shouldn't even be set, - and if it is, the query produced would be invalid. -* Multipart keys, even if containing some or all numeric columns, - are treated the same as non-numeric keys - - If the query is " = " (quotes or not): - - records in range start key flag HA_READ_KEY_EXACT, - end key flag HA_READ_AFTER_KEY (incorrect) - - any other: start key flag HA_READ_KEY_OR_NEXT, - end key flag HA_READ_AFTER_KEY (correct) - -* 'like' queries (of key) - - Numeric, full table scan - - Non-numeric - records_in_range: start_key 0 end_key 3 - other : start_key 1 end_key 3 - -* If the key flag is HA_READ_AFTER_KEY: - if start_key, append > - if end_key, append <= - -* If create_where_key was called by records_in_range: - - - if the key is numeric: - start key flag is 0 when end key is NULL, end key flag is 3 or 4 - - if create_where_key was called by any other function: - start key flag is 1 when end key is NULL, end key flag is 3 or 4 - - if the key is non-numeric, or multipart - When the query is an exact match, the start key flag is 0, - end key flag is 3 for what should be a no-range condition where - you should have 0 and max key NULL, which it is if called by - read_range_first - -Conclusion: - -1. Need logic to determin if a key is min or max when the flag is -HA_READ_AFTER_KEY, and handle appending correct operator accordingly - -2. Need a boolean flag to pass to create_where_from_key, used in the -switch statement. Add 1 to the flag if: - - start key flag is HA_READ_KEY_EXACT and the end key is NULL - -*/ - -bool ha_federated::create_where_from_key(String *to, - KEY *key_info, - const key_range *start_key, - const key_range *end_key, - bool from_records_in_range) -{ - bool both_not_null= - (start_key != NULL && end_key != NULL) ? TRUE : FALSE; - const byte *ptr; - uint remainder, length; - char tmpbuff[FEDERATED_QUERY_BUFFER_SIZE]; - String tmp(tmpbuff, sizeof(tmpbuff), system_charset_info); - const key_range *ranges[2]= { start_key, end_key }; - DBUG_ENTER("ha_federated::create_where_from_key"); - - tmp.length(0); - if (start_key == NULL && end_key == NULL) - DBUG_RETURN(1); - - for (int i= 0; i <= 1; i++) - { - bool needs_quotes; - KEY_PART_INFO *key_part; - if (ranges[i] == NULL) - continue; - - if (both_not_null) - { - if (i > 0) - tmp.append(FEDERATED_CONJUNCTION); - else - tmp.append(FEDERATED_OPENPAREN); - } - - for (key_part= key_info->key_part, - remainder= key_info->key_parts, - length= ranges[i]->length, - ptr= ranges[i]->key; ; - remainder--, - key_part++) - { - Field *field= key_part->field; - uint store_length= key_part->store_length; - uint part_length= min(store_length, length); - needs_quotes= 1; - DBUG_DUMP("key, start of loop", (uchar *)ptr, length); - - if (key_part->null_bit) - { - if (*ptr++) - { - /* - We got "IS [NOT] NULL" condition against nullable column. We - distinguish between "IS NOT NULL" and "IS NULL" by flag. For - "IS NULL", flag is set to HA_READ_KEY_EXACT. - */ - if (emit_key_part_name(&tmp, key_part) || - tmp.append(ranges[i]->flag == HA_READ_KEY_EXACT ? - FEDERATED_ISNULL : " IS NOT NULL ")) - DBUG_RETURN(1); - /* - We need to adjust pointer and length to be prepared for next - key part. As well as check if this was last key part. - */ - goto prepare_for_next_key_part; - } - } - - if (tmp.append(FEDERATED_OPENPAREN)) - DBUG_RETURN(1); - - switch(ranges[i]->flag) { - case(HA_READ_KEY_EXACT): - DBUG_PRINT("info", ("federated HA_READ_KEY_EXACT %d", i)); - if (store_length >= length || - !needs_quotes || - key_part->type == HA_KEYTYPE_BIT || - field->result_type() != STRING_RESULT) - { - if (emit_key_part_name(&tmp, key_part)) - DBUG_RETURN(1); - - if (from_records_in_range) - { - if (tmp.append(FEDERATED_GE)) - DBUG_RETURN(1); - } - else - { - if (tmp.append(FEDERATED_EQ)) - DBUG_RETURN(1); - } - - if (emit_key_part_element(&tmp, key_part, needs_quotes, 0, ptr, - part_length)) - DBUG_RETURN(1); - } - else - /* LIKE */ - { - if (emit_key_part_name(&tmp, key_part) || - tmp.append(FEDERATED_LIKE) || - emit_key_part_element(&tmp, key_part, needs_quotes, 1, ptr, - part_length)) - DBUG_RETURN(1); - } - break; - case(HA_READ_AFTER_KEY): - DBUG_PRINT("info", ("federated HA_READ_AFTER_KEY %d", i)); - if (store_length >= length) /* end key */ - { - if (emit_key_part_name(&tmp, key_part)) - DBUG_RETURN(1); - - if (i > 0) /* end key */ - { - if (tmp.append(FEDERATED_LE)) - DBUG_RETURN(1); - } - else /* start key */ - { - if (tmp.append(FEDERATED_GT)) - DBUG_RETURN(1); - } - - if (emit_key_part_element(&tmp, key_part, needs_quotes, 0, ptr, - part_length)) - { - DBUG_RETURN(1); - } - break; - } - case(HA_READ_KEY_OR_NEXT): - DBUG_PRINT("info", ("federated HA_READ_KEY_OR_NEXT %d", i)); - if (emit_key_part_name(&tmp, key_part) || - tmp.append(FEDERATED_GE) || - emit_key_part_element(&tmp, key_part, needs_quotes, 0, ptr, - part_length)) - DBUG_RETURN(1); - break; - case(HA_READ_BEFORE_KEY): - DBUG_PRINT("info", ("federated HA_READ_BEFORE_KEY %d", i)); - if (store_length >= length) - { - if (emit_key_part_name(&tmp, key_part) || - tmp.append(FEDERATED_LT) || - emit_key_part_element(&tmp, key_part, needs_quotes, 0, ptr, - part_length)) - DBUG_RETURN(1); - break; - } - case(HA_READ_KEY_OR_PREV): - DBUG_PRINT("info", ("federated HA_READ_KEY_OR_PREV %d", i)); - if (emit_key_part_name(&tmp, key_part) || - tmp.append(FEDERATED_LE) || - emit_key_part_element(&tmp, key_part, needs_quotes, 0, ptr, - part_length)) - DBUG_RETURN(1); - break; - default: - DBUG_PRINT("info",("cannot handle flag %d", ranges[i]->flag)); - DBUG_RETURN(1); - } - if (tmp.append(FEDERATED_CLOSEPAREN)) - DBUG_RETURN(1); - -prepare_for_next_key_part: - if (store_length >= length) - break; - DBUG_PRINT("info", ("remainder %d", remainder)); - DBUG_ASSERT(remainder > 1); - length-= store_length; - /* - For nullable columns, null-byte is already skipped before, that is - ptr was incremented by 1. Since store_length still counts null-byte, - we need to subtract 1 from store_length. - */ - ptr+= store_length - test(key_part->null_bit); - if (tmp.append(FEDERATED_AND)) - DBUG_RETURN(1); - - DBUG_PRINT("info", - ("create_where_from_key WHERE clause: %s", - tmp.c_ptr_quick())); - } - } - if (both_not_null) - if (tmp.append(FEDERATED_CLOSEPAREN)) - DBUG_RETURN(1); - - if (to->append(FEDERATED_WHERE)) - DBUG_RETURN(1); - - if (to->append(tmp)) - DBUG_RETURN(1); - - DBUG_RETURN(0); -} - -/* - Example of simple lock controls. The "share" it creates is structure we will - pass to each federated handler. Do you have to have one of these? Well, you - have pieces that are used for locking, and they are needed to function. -*/ - -static FEDERATED_SHARE *get_share(const char *table_name, TABLE *table) -{ - char *select_query; - char query_buffer[FEDERATED_QUERY_BUFFER_SIZE]; - Field **field; - String query(query_buffer, sizeof(query_buffer), &my_charset_bin); - FEDERATED_SHARE *share= NULL, tmp_share; - /* - In order to use this string, we must first zero it's length, - or it will contain garbage - */ - query.length(0); - - pthread_mutex_lock(&federated_mutex); - - if (parse_url(&tmp_share, table, 0)) - goto error; - - /* TODO: change tmp_share.scheme to LEX_STRING object */ - if (!(share= (FEDERATED_SHARE *) hash_search(&federated_open_tables, - (byte*) tmp_share.scheme, - tmp_share. - connect_string_length))) - { - query.set_charset(system_charset_info); - query.append(FEDERATED_SELECT); - for (field= table->field; *field; field++) - { - append_ident(&query, (*field)->field_name, - (uint) strlen((*field)->field_name), ident_quote_char); - query.append(FEDERATED_COMMA); - } - query.length(query.length() - (uint) strlen(FEDERATED_COMMA)); - query.append(FEDERATED_FROM); - - tmp_share.table_name_length= (uint) strlen(tmp_share.table_name); - append_ident(&query, tmp_share.table_name, - tmp_share.table_name_length, ident_quote_char); - - if (!(share= (FEDERATED_SHARE *) - my_multi_malloc(MYF(MY_WME), - &share, sizeof(*share), - &select_query, query.length()+1, - NullS))) - goto error; - - memcpy(share, &tmp_share, sizeof(tmp_share)); - memcpy(select_query, query.ptr(), query.length()+1); - - share->select_query= select_query; - share->use_count= 0; - DBUG_PRINT("info", - ("share->select_query %s", share->select_query)); - - if (my_hash_insert(&federated_open_tables, (byte*) share)) - goto error; - thr_lock_init(&share->lock); - pthread_mutex_init(&share->mutex, MY_MUTEX_INIT_FAST); - } - else - { - /* - Free tmp_share.scheme allocated in the parse_url() - as we found share in the hash and tmp_share isn't needed anymore. - */ - my_free((gptr) tmp_share.scheme, MYF(MY_ALLOW_ZERO_PTR)); - } - share->use_count++; - pthread_mutex_unlock(&federated_mutex); - - return share; - -error: - pthread_mutex_unlock(&federated_mutex); - my_free((gptr) tmp_share.scheme, MYF(MY_ALLOW_ZERO_PTR)); - my_free((gptr) share, MYF(MY_ALLOW_ZERO_PTR)); - return NULL; -} - - -/* - Free lock controls. We call this whenever we close a table. - If the table had the last reference to the share then we - free memory associated with it. -*/ - -static int free_share(FEDERATED_SHARE *share) -{ - DBUG_ENTER("free_share"); - - pthread_mutex_lock(&federated_mutex); - if (!--share->use_count) - { - hash_delete(&federated_open_tables, (byte*) share); - my_free((gptr) share->scheme, MYF(MY_ALLOW_ZERO_PTR)); - thr_lock_delete(&share->lock); - VOID(pthread_mutex_destroy(&share->mutex)); - my_free((gptr) share, MYF(0)); - } - pthread_mutex_unlock(&federated_mutex); - - DBUG_RETURN(0); -} - - -ha_rows ha_federated::records_in_range(uint inx, key_range *start_key, - key_range *end_key) -{ - /* - - We really want indexes to be used as often as possible, therefore - we just need to hard-code the return value to a very low number to - force the issue - -*/ - DBUG_ENTER("ha_federated::records_in_range"); - DBUG_RETURN(FEDERATED_RECORDS_IN_RANGE); -} -/* - If frm_error() is called then we will use this to to find out - what file extentions exist for the storage engine. This is - also used by the default rename_table and delete_table method - in handler.cc. -*/ - -const char **ha_federated::bas_ext() const -{ - static const char *ext[]= - { - NullS - }; - return ext; -} - - -/* - Used for opening tables. The name will be the name of the file. - A table is opened when it needs to be opened. For instance - when a request comes in for a select on the table (tables are not - open and closed for each request, they are cached). - - Called from handler.cc by handler::ha_open(). The server opens - all tables by calling ha_open() which then calls the handler - specific open(). -*/ - -int ha_federated::open(const char *name, int mode, uint test_if_locked) -{ - DBUG_ENTER("ha_federated::open"); - - if (!(share= get_share(name, table))) - DBUG_RETURN(1); - thr_lock_data_init(&share->lock, &lock, NULL); - - DBUG_ASSERT(mysql == NULL); - - ref_length= (table->s->primary_key != MAX_KEY ? - table->key_info[table->s->primary_key].key_length : - table->s->reclength); - DBUG_PRINT("info", ("ref_length: %u", ref_length)); - - reset(); - - DBUG_RETURN(0); -} - - -/* - Closes a table. We call the free_share() function to free any resources - that we have allocated in the "shared" structure. - - Called from sql_base.cc, sql_select.cc, and table.cc. - In sql_select.cc it is only used to close up temporary tables or during - the process where a temporary table is converted over to being a - myisam table. - For sql_base.cc look at close_data_tables(). -*/ - -int ha_federated::close(void) -{ - int retval; - DBUG_ENTER("ha_federated::close"); - - /* free the result set */ - if (stored_result) - { - mysql_free_result(stored_result); - stored_result= 0; - } - /* Disconnect from mysql */ - mysql_close(mysql); - mysql= NULL; - retval= free_share(share); - DBUG_RETURN(retval); - -} - -/* - - Checks if a field in a record is SQL NULL. - - SYNOPSIS - field_in_record_is_null() - table TABLE pointer, MySQL table object - field Field pointer, MySQL field object - record char pointer, contains record - - DESCRIPTION - This method uses the record format information in table to track - the null bit in record. - - RETURN VALUE - 1 if NULL - 0 otherwise -*/ - -inline uint field_in_record_is_null(TABLE *table, - Field *field, - char *record) -{ - int null_offset; - DBUG_ENTER("ha_federated::field_in_record_is_null"); - - if (!field->null_ptr) - DBUG_RETURN(0); - - null_offset= (uint) ((char*)field->null_ptr - (char*)table->record[0]); - - if (record[null_offset] & field->null_bit) - DBUG_RETURN(1); - - DBUG_RETURN(0); -} - - -/** - @brief Construct the INSERT statement. - - @details This method will construct the INSERT statement and appends it to - the supplied query string buffer. - - @return - @retval FALSE No error - @retval TRUE Failure -*/ - -bool ha_federated::append_stmt_insert(String *query) -{ - char insert_buffer[FEDERATED_QUERY_BUFFER_SIZE]; - Field **field; - uint tmp_length; - - /* The main insert query string */ - String insert_string(insert_buffer, sizeof(insert_buffer), &my_charset_bin); - DBUG_ENTER("ha_federated::append_stmt_insert"); - - insert_string.length(0); - - if (replace_duplicates) - insert_string.append(STRING_WITH_LEN("REPLACE INTO ")); - else if (ignore_duplicates && !insert_dup_update) - insert_string.append(STRING_WITH_LEN("INSERT IGNORE INTO ")); - else - insert_string.append(STRING_WITH_LEN("INSERT INTO ")); - append_ident(&insert_string, share->table_name, share->table_name_length, - ident_quote_char); - insert_string.append(FEDERATED_OPENPAREN); - tmp_length= insert_string.length() - (uint) strlen(FEDERATED_COMMA); - - /* - loop through the field pointer array, add any fields to both the values - list and the fields list that match the current query id - */ - for (field= table->field; *field; field++) - { - /* append the field name */ - append_ident(&insert_string, (*field)->field_name, - (uint) strlen((*field)->field_name), ident_quote_char); - - /* append commas between both fields and fieldnames */ - /* - unfortunately, we can't use the logic - if *(fields + 1) to make the following - appends conditional because we may not append - if the next field doesn't match the condition: - (((*field)->query_id && (*field)->query_id == current_query_id) - */ - insert_string.append(FEDERATED_COMMA); - } - - /* - remove trailing comma - */ - insert_string.length(insert_string.length() - (uint) strlen(FEDERATED_COMMA)); - - /* - if there were no fields, we don't want to add a closing paren - AND, we don't want to chop off the last char '(' - insert will be "INSERT INTO t1 VALUES ();" - */ - if (insert_string.length() > tmp_length) - { - insert_string.append(FEDERATED_CLOSEPAREN); - } - - insert_string.append(FEDERATED_VALUES); - - DBUG_RETURN(query->append(insert_string)); -} - - -/* - write_row() inserts a row. No extra() hint is given currently if a bulk load - is happeneding. buf() is a byte array of data. You can use the field - information to extract the data from the native byte array type. - Example of this would be: - for (Field **field=table->field ; *field ; field++) - { - ... - } - - Called from item_sum.cc, item_sum.cc, sql_acl.cc, sql_insert.cc, - sql_insert.cc, sql_select.cc, sql_table.cc, sql_udf.cc, and sql_update.cc. -*/ - -int ha_federated::write_row(byte *buf) -{ - char values_buffer[FEDERATED_QUERY_BUFFER_SIZE]; - char insert_field_value_buffer[STRING_BUFFER_USUAL_SIZE]; - Field **field; - uint tmp_length; - int error= 0; - bool use_bulk_insert; - bool auto_increment_update_required= (table->next_number_field != NULL); - - /* The string containing the values to be added to the insert */ - String values_string(values_buffer, sizeof(values_buffer), &my_charset_bin); - /* The actual value of the field, to be added to the values_string */ - String insert_field_value_string(insert_field_value_buffer, - sizeof(insert_field_value_buffer), - &my_charset_bin); - values_string.length(0); - insert_field_value_string.length(0); - DBUG_ENTER("ha_federated::write_row"); - - statistic_increment(table->in_use->status_var.ha_write_count, &LOCK_status); - if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_INSERT) - table->timestamp_field->set_time(); - - /* - start both our field and field values strings - We must disable multi-row insert for "INSERT...ON DUPLICATE KEY UPDATE" - Ignore duplicates is always true when insert_dup_update is true. - When replace_duplicates == TRUE, we can safely enable multi-row insert. - When performing multi-row insert, we only collect the columns values for - the row. The start of the statement is only created when the first - row is copied in to the bulk_insert string. - */ - if (!(use_bulk_insert= bulk_insert.str && - (!insert_dup_update || replace_duplicates))) - append_stmt_insert(&values_string); - - values_string.append(FEDERATED_OPENPAREN); - tmp_length= values_string.length(); - - /* - loop through the field pointer array, add any fields to both the values - list and the fields list that match the current query id - */ - for (field= table->field; *field; field++) - { - if ((*field)->is_null()) - insert_field_value_string.append(FEDERATED_NULL); - else - { - (*field)->val_str(&insert_field_value_string); - values_string.append(value_quote_char); - insert_field_value_string.print(&values_string); - values_string.append(value_quote_char); - - insert_field_value_string.length(0); - } - - /* append the value */ - values_string.append(insert_field_value_string); - insert_field_value_string.length(0); - - /* append commas between both fields and fieldnames */ - /* - unfortunately, we can't use the logic - if *(fields + 1) to make the following - appends conditional because we may not append - if the next field doesn't match the condition: - (((*field)->query_id && (*field)->query_id == current_query_id) - */ - values_string.append(FEDERATED_COMMA); - } - - /* - if there were no fields, we don't want to add a closing paren - AND, we don't want to chop off the last char '(' - insert will be "INSERT INTO t1 VALUES ();" - */ - if (values_string.length() > tmp_length) - { - /* chops off leading commas */ - values_string.length(values_string.length() - (uint) strlen(FEDERATED_COMMA)); - } - /* we always want to append this, even if there aren't any fields */ - values_string.append(FEDERATED_CLOSEPAREN); - - if (use_bulk_insert) - { - /* - Send the current bulk insert out if appending the current row would - cause the statement to overflow the packet size, otherwise set - auto_increment_update_required to FALSE as no query was executed. - */ - if (bulk_insert.length + values_string.length() + bulk_padding > - mysql->net.max_packet_size && bulk_insert.length) - { - error= real_query(bulk_insert.str, bulk_insert.length); - bulk_insert.length= 0; - } - else - auto_increment_update_required= FALSE; - - if (bulk_insert.length == 0) - { - char insert_buffer[FEDERATED_QUERY_BUFFER_SIZE]; - String insert_string(insert_buffer, sizeof(insert_buffer), - &my_charset_bin); - insert_string.length(0); - append_stmt_insert(&insert_string); - dynstr_append_mem(&bulk_insert, insert_string.ptr(), - insert_string.length()); - } - else - dynstr_append_mem(&bulk_insert, ",", 1); - - dynstr_append_mem(&bulk_insert, values_string.ptr(), - values_string.length()); - } - else - { - error= real_query(values_string.ptr(), values_string.length()); - } - - if (error) - { - DBUG_RETURN(stash_remote_error()); - } - /* - If the table we've just written a record to contains an auto_increment - field, then store the last_insert_id() value from the foreign server - */ - if (auto_increment_update_required) - { - update_auto_increment(); - - /* mysql_insert() uses this for protocol return value */ - table->next_number_field->store(auto_increment_value, 1); - } - - DBUG_RETURN(0); -} - - -/** - @brief Prepares the storage engine for bulk inserts. - - @param[in] rows estimated number of rows in bulk insert - or 0 if unknown. - - @details Initializes memory structures required for bulk insert. -*/ - -void ha_federated::start_bulk_insert(ha_rows rows) -{ - uint page_size; - DBUG_ENTER("ha_federated::start_bulk_insert"); - - dynstr_free(&bulk_insert); - - /** - We don't bother with bulk-insert semantics when the estimated rows == 1 - The rows value will be 0 if the server does not know how many rows - would be inserted. This can occur when performing INSERT...SELECT - */ - - if (rows == 1) - DBUG_VOID_RETURN; - - /* - Make sure we have an open connection so that we know the - maximum packet size. - */ - if (!mysql && real_connect()) - DBUG_VOID_RETURN; - - page_size= (uint) my_getpagesize(); - - if (init_dynamic_string(&bulk_insert, NULL, page_size, page_size)) - DBUG_VOID_RETURN; - - bulk_insert.length= 0; - DBUG_VOID_RETURN; -} - - -/** - @brief End bulk insert. - - @details This method will send any remaining rows to the remote server. - Finally, it will deinitialize the bulk insert data structure. - - @return Operation status - @retval 0 No error - @retval != 0 Error occured at remote server. Also sets my_errno. -*/ - -int ha_federated::end_bulk_insert() -{ - int error= 0; - DBUG_ENTER("ha_federated::end_bulk_insert"); - - if (bulk_insert.str && bulk_insert.length) - { - if (real_query(bulk_insert.str, bulk_insert.length)) - error= stash_remote_error(); - else - if (table->next_number_field) - update_auto_increment(); - } - - dynstr_free(&bulk_insert); - - DBUG_RETURN(my_errno= error); -} - - -/* - ha_federated::update_auto_increment - - This method ensures that last_insert_id() works properly. What it simply does - is calls last_insert_id() on the foreign database immediately after insert - (if the table has an auto_increment field) and sets the insert id via - thd->insert_id(ID) (as well as storing thd->prev_insert_id) -*/ -void ha_federated::update_auto_increment(void) -{ - THD *thd= current_thd; - DBUG_ENTER("ha_federated::update_auto_increment"); - - ha_federated::info(HA_STATUS_AUTO); - thd->insert_id(auto_increment_value); - DBUG_PRINT("info",("last_insert_id: %ld", (long) auto_increment_value)); - - DBUG_VOID_RETURN; -} - -int ha_federated::optimize(THD* thd, HA_CHECK_OPT* check_opt) -{ - char query_buffer[STRING_BUFFER_USUAL_SIZE]; - String query(query_buffer, sizeof(query_buffer), &my_charset_bin); - DBUG_ENTER("ha_federated::optimize"); - - query.length(0); - - query.set_charset(system_charset_info); - query.append(FEDERATED_OPTIMIZE); - append_ident(&query, share->table_name, share->table_name_length, - ident_quote_char); - - if (real_query(query.ptr(), query.length())) - { - DBUG_RETURN(stash_remote_error()); - } - - DBUG_RETURN(0); -} - - -int ha_federated::repair(THD* thd, HA_CHECK_OPT* check_opt) -{ - char query_buffer[STRING_BUFFER_USUAL_SIZE]; - String query(query_buffer, sizeof(query_buffer), &my_charset_bin); - DBUG_ENTER("ha_federated::repair"); - - query.length(0); - - query.set_charset(system_charset_info); - query.append(FEDERATED_REPAIR); - append_ident(&query, share->table_name, share->table_name_length, - ident_quote_char); - if (check_opt->flags & T_QUICK) - query.append(FEDERATED_QUICK); - if (check_opt->flags & T_EXTEND) - query.append(FEDERATED_EXTENDED); - if (check_opt->sql_flags & TT_USEFRM) - query.append(FEDERATED_USE_FRM); - - if (real_query(query.ptr(), query.length())) - { - DBUG_RETURN(stash_remote_error()); - } - - DBUG_RETURN(0); -} - - -/* - Yes, update_row() does what you expect, it updates a row. old_data will have - the previous row record in it, while new_data will have the newest data in - it. - - Keep in mind that the server can do updates based on ordering if an ORDER BY - clause was used. Consecutive ordering is not guarenteed. - Currently new_data will not have an updated auto_increament record, or - and updated timestamp field. You can do these for federated by doing these: - if (table->timestamp_on_update_now) - update_timestamp(new_row+table->timestamp_on_update_now-1); - if (table->next_number_field && record == table->record[0]) - update_auto_increment(); - - Called from sql_select.cc, sql_acl.cc, sql_update.cc, and sql_insert.cc. -*/ - -int ha_federated::update_row(const byte *old_data, byte *new_data) -{ - /* - This used to control how the query was built. If there was a - primary key, the query would be built such that there was a where - clause with only that column as the condition. This is flawed, - because if we have a multi-part primary key, it would only use the - first part! We don't need to do this anyway, because - read_range_first will retrieve the correct record, which is what - is used to build the WHERE clause. We can however use this to - append a LIMIT to the end if there is NOT a primary key. Why do - this? Because we only are updating one record, and LIMIT enforces - this. - */ - bool has_a_primary_key= (table->s->primary_key == 0 ? TRUE : FALSE); - /* - buffers for following strings - */ - char field_value_buffer[STRING_BUFFER_USUAL_SIZE]; - char update_buffer[FEDERATED_QUERY_BUFFER_SIZE]; - char where_buffer[FEDERATED_QUERY_BUFFER_SIZE]; - - /* Work area for field values */ - String field_value(field_value_buffer, sizeof(field_value_buffer), - &my_charset_bin); - /* stores the update query */ - String update_string(update_buffer, - sizeof(update_buffer), - &my_charset_bin); - /* stores the WHERE clause */ - String where_string(where_buffer, - sizeof(where_buffer), - &my_charset_bin); - DBUG_ENTER("ha_federated::update_row"); - /* - set string lengths to 0 to avoid misc chars in string - */ - field_value.length(0); - update_string.length(0); - where_string.length(0); - - if (ignore_duplicates) - update_string.append(STRING_WITH_LEN("UPDATE IGNORE ")); - else - update_string.append(STRING_WITH_LEN("UPDATE ")); - append_ident(&update_string, share->table_name, - share->table_name_length, ident_quote_char); - update_string.append(FEDERATED_SET); - -/* - In this loop, we want to match column names to values being inserted - (while building INSERT statement). - - Iterate through table->field (new data) and share->old_field (old_data) - using the same index to create an SQL UPDATE statement. New data is - used to create SET field=value and old data is used to create WHERE - field=oldvalue - */ - - for (Field **field= table->field; *field; field++) - { - size_t field_name_length= strlen((*field)->field_name); - append_ident(&where_string, (*field)->field_name, (uint) field_name_length, - ident_quote_char); - append_ident(&update_string, (*field)->field_name, (uint) field_name_length, - ident_quote_char); - update_string.append(FEDERATED_EQ); - - if ((*field)->is_null()) - update_string.append(FEDERATED_NULL); - else - { - /* otherwise = */ - (*field)->val_str(&field_value); - update_string.append(value_quote_char); - field_value.print(&update_string); - update_string.append(value_quote_char); - field_value.length(0); - } - - if (field_in_record_is_null(table, *field, (char*) old_data)) - where_string.append(FEDERATED_ISNULL); - else - { - where_string.append(FEDERATED_EQ); - (*field)->val_str(&field_value, - (char*) (old_data + (*field)->offset())); - where_string.append(value_quote_char); - field_value.print(&where_string); - where_string.append(value_quote_char); - field_value.length(0); - } - - /* - Only append conjunctions if we have another field in which - to iterate - */ - if (*(field + 1)) - { - update_string.append(FEDERATED_COMMA); - where_string.append(FEDERATED_AND); - } - } - update_string.append(FEDERATED_WHERE); - update_string.append(where_string); - /* - If this table has not a primary key, then we could possibly - update multiple rows. We want to make sure to only update one! - */ - if (!has_a_primary_key) - update_string.append(FEDERATED_LIMIT1); - - if (real_query(update_string.ptr(), update_string.length())) - { - DBUG_RETURN(stash_remote_error()); - } - DBUG_RETURN(0); -} - -/* - This will delete a row. 'buf' will contain a copy of the row to be =deleted. - The server will call this right after the current row has been called (from - either a previous rnd_next() or index call). - If you keep a pointer to the last row or can access a primary key it will - make doing the deletion quite a bit easier. - Keep in mind that the server does no guarentee consecutive deletions. - ORDER BY clauses can be used. - - Called in sql_acl.cc and sql_udf.cc to manage internal table information. - Called in sql_delete.cc, sql_insert.cc, and sql_select.cc. In sql_select - it is used for removing duplicates while in insert it is used for REPLACE - calls. -*/ - -int ha_federated::delete_row(const byte *buf) -{ - char delete_buffer[FEDERATED_QUERY_BUFFER_SIZE]; - char data_buffer[FEDERATED_QUERY_BUFFER_SIZE]; - - String delete_string(delete_buffer, sizeof(delete_buffer), &my_charset_bin); - String data_string(data_buffer, sizeof(data_buffer), &my_charset_bin); - DBUG_ENTER("ha_federated::delete_row"); - - delete_string.length(0); - delete_string.append(FEDERATED_DELETE); - delete_string.append(FEDERATED_FROM); - append_ident(&delete_string, share->table_name, - share->table_name_length, ident_quote_char); - delete_string.append(FEDERATED_WHERE); - - for (Field **field= table->field; *field; field++) - { - Field *cur_field= *field; - data_string.length(0); - append_ident(&delete_string, (*field)->field_name, - (uint) strlen((*field)->field_name), ident_quote_char); - - if (cur_field->is_null()) - { - delete_string.append(FEDERATED_ISNULL); - } - else - { - delete_string.append(FEDERATED_EQ); - cur_field->val_str(&data_string); - delete_string.append(value_quote_char); - data_string.print(&delete_string); - delete_string.append(value_quote_char); - } - - delete_string.append(FEDERATED_AND); - } - delete_string.length(delete_string.length()-5); // Remove trailing AND - - delete_string.append(FEDERATED_LIMIT1); - DBUG_PRINT("info", - ("Delete sql: %s", delete_string.c_ptr_quick())); - if (real_query(delete_string.ptr(), delete_string.length())) - { - DBUG_RETURN(stash_remote_error()); - } - deleted+= (ha_rows) mysql->affected_rows; - records-= (ha_rows) mysql->affected_rows; - DBUG_PRINT("info", - ("rows deleted %ld rows deleted for all time %ld", - (long) mysql->affected_rows, (long) deleted)); - - DBUG_RETURN(0); -} - - -/* - Positions an index cursor to the index specified in the handle. Fetches the - row if available. If the key value is null, begin at the first key of the - index. This method, which is called in the case of an SQL statement having - a WHERE clause on a non-primary key index, simply calls index_read_idx. -*/ - -int ha_federated::index_read(byte *buf, const byte *key, - uint key_len, ha_rkey_function find_flag) -{ - DBUG_ENTER("ha_federated::index_read"); - - if (stored_result) - mysql_free_result(stored_result); - DBUG_RETURN(index_read_idx_with_result_set(buf, active_index, key, - key_len, find_flag, - &stored_result)); -} - - -/* - Positions an index cursor to the index specified in key. Fetches the - row if any. This is only used to read whole keys. - - This method is called via index_read in the case of a WHERE clause using - a primary key index OR is called DIRECTLY when the WHERE clause - uses a PRIMARY KEY index. - - NOTES - This uses an internal result set that is deleted before function - returns. We need to be able to be calable from ha_rnd_pos() -*/ - -int ha_federated::index_read_idx(byte *buf, uint index, const byte *key, - uint key_len, enum ha_rkey_function find_flag) -{ - int retval; - MYSQL_RES *mysql_result; - DBUG_ENTER("ha_federated::index_read_idx"); - - if ((retval= index_read_idx_with_result_set(buf, index, key, - key_len, find_flag, - &mysql_result))) - DBUG_RETURN(retval); - mysql_free_result(mysql_result); - DBUG_RETURN(retval); -} - - -/* - Create result set for rows matching query and return first row - - RESULT - 0 ok In this case *result will contain the result set - table->status == 0 - # error In this case *result will contain 0 - table->status == STATUS_NOT_FOUND -*/ - -int ha_federated::index_read_idx_with_result_set(byte *buf, uint index, - const byte *key, - uint key_len, - ha_rkey_function find_flag, - MYSQL_RES **result) -{ - int retval; - char error_buffer[FEDERATED_QUERY_BUFFER_SIZE]; - char index_value[STRING_BUFFER_USUAL_SIZE]; - char sql_query_buffer[FEDERATED_QUERY_BUFFER_SIZE]; - String index_string(index_value, - sizeof(index_value), - &my_charset_bin); - String sql_query(sql_query_buffer, - sizeof(sql_query_buffer), - &my_charset_bin); - key_range range; - DBUG_ENTER("ha_federated::index_read_idx_with_result_set"); - - *result= 0; // In case of errors - index_string.length(0); - sql_query.length(0); - statistic_increment(table->in_use->status_var.ha_read_key_count, - &LOCK_status); - - sql_query.append(share->select_query); - - range.key= key; - range.length= key_len; - range.flag= find_flag; - create_where_from_key(&index_string, - &table->key_info[index], - &range, - NULL, 0); - sql_query.append(index_string); - - if (real_query(sql_query.ptr(), sql_query.length())) - { - my_sprintf(error_buffer, (error_buffer, "error: %d '%s'", - mysql_errno(mysql), mysql_error(mysql))); - retval= ER_QUERY_ON_FOREIGN_DATA_SOURCE; - goto error; - } - if (!(*result= mysql_store_result(mysql))) - { - retval= HA_ERR_END_OF_FILE; - goto error; - } - if (!(retval= read_next(buf, *result))) - DBUG_RETURN(retval); - - mysql_free_result(*result); - *result= 0; - table->status= STATUS_NOT_FOUND; - DBUG_RETURN(retval); - -error: - table->status= STATUS_NOT_FOUND; - my_error(retval, MYF(0), error_buffer); - DBUG_RETURN(retval); -} - - -/* - This method is used exlusevely by filesort() to check if we - can create sorting buffers of necessary size. - If the handler returns more records that it declares - here server can just crash on filesort(). - We cannot guarantee that's not going to happen with - the FEDERATED engine, as we have records==0 always if the - client is a VIEW, and for the table the number of - records can inpredictably change during execution. - So we return maximum possible value here. -*/ - -ha_rows ha_federated::estimate_rows_upper_bound() -{ - return HA_POS_ERROR; -} - - -/* Initialized at each key walk (called multiple times unlike rnd_init()) */ - -int ha_federated::index_init(uint keynr) -{ - DBUG_ENTER("ha_federated::index_init"); - DBUG_PRINT("info", ("table: '%s' key: %u", table->s->table_name, keynr)); - active_index= keynr; - DBUG_RETURN(0); -} - - -/* - Read first range -*/ - -int ha_federated::read_range_first(const key_range *start_key, - const key_range *end_key, - bool eq_range_arg, bool sorted) -{ - char sql_query_buffer[FEDERATED_QUERY_BUFFER_SIZE]; - int retval; - String sql_query(sql_query_buffer, - sizeof(sql_query_buffer), - &my_charset_bin); - DBUG_ENTER("ha_federated::read_range_first"); - - DBUG_ASSERT(!(start_key == NULL && end_key == NULL)); - - sql_query.length(0); - sql_query.append(share->select_query); - create_where_from_key(&sql_query, - &table->key_info[active_index], - start_key, end_key, 0); - - if (stored_result) - { - mysql_free_result(stored_result); - stored_result= 0; - } - if (real_query(sql_query.ptr(), sql_query.length())) - { - retval= ER_QUERY_ON_FOREIGN_DATA_SOURCE; - goto error; - } - sql_query.length(0); - - if (!(stored_result= mysql_store_result(mysql))) - { - retval= HA_ERR_END_OF_FILE; - goto error; - } - - retval= read_next(table->record[0], stored_result); - DBUG_RETURN(retval); - -error: - table->status= STATUS_NOT_FOUND; - DBUG_RETURN(retval); -} - - -int ha_federated::read_range_next() -{ - int retval; - DBUG_ENTER("ha_federated::read_range_next"); - retval= rnd_next(table->record[0]); - DBUG_RETURN(retval); -} - - -/* Used to read forward through the index. */ -int ha_federated::index_next(byte *buf) -{ - DBUG_ENTER("ha_federated::index_next"); - statistic_increment(table->in_use->status_var.ha_read_next_count, - &LOCK_status); - DBUG_RETURN(read_next(buf, stored_result)); -} - - -/* - rnd_init() is called when the system wants the storage engine to do a table - scan. - - This is the method that gets data for the SELECT calls. - - See the federated in the introduction at the top of this file to see when - rnd_init() is called. - - Called from filesort.cc, records.cc, sql_handler.cc, sql_select.cc, - sql_table.cc, and sql_update.cc. -*/ - -int ha_federated::rnd_init(bool scan) -{ - DBUG_ENTER("ha_federated::rnd_init"); - /* - The use of the 'scan' flag is incredibly important for this handler - to work properly, especially with updates containing WHERE clauses - using indexed columns. - - When the initial query contains a WHERE clause of the query using an - indexed column, it's index_read_idx that selects the exact record from - the foreign database. - - When there is NO index in the query, either due to not having a WHERE - clause, or the WHERE clause is using columns that are not indexed, a - 'full table scan' done by rnd_init, which in this situation simply means - a 'select * from ...' on the foreign table. - - In other words, this 'scan' flag gives us the means to ensure that if - there is an index involved in the query, we want index_read_idx to - retrieve the exact record (scan flag is 0), and do not want rnd_init - to do a 'full table scan' and wipe out that result set. - - Prior to using this flag, the problem was most apparent with updates. - - An initial query like 'UPDATE tablename SET anything = whatever WHERE - indexedcol = someval', index_read_idx would get called, using a query - constructed with a WHERE clause built from the values of index ('indexcol' - in this case, having a value of 'someval'). mysql_store_result would - then get called (this would be the result set we want to use). - - After this rnd_init (from sql_update.cc) would be called, it would then - unecessarily call "select * from table" on the foreign table, then call - mysql_store_result, which would wipe out the correct previous result set - from the previous call of index_read_idx's that had the result set - containing the correct record, hence update the wrong row! - - */ - - if (scan) - { - if (stored_result) - { - mysql_free_result(stored_result); - stored_result= 0; - } - - if (real_query(share->select_query, (uint) strlen(share->select_query))) - goto error; - - stored_result= mysql_store_result(mysql); - if (!stored_result) - goto error; - } - DBUG_RETURN(0); - -error: - DBUG_RETURN(stash_remote_error()); -} - - -int ha_federated::rnd_end() -{ - DBUG_ENTER("ha_federated::rnd_end"); - DBUG_RETURN(index_end()); -} - - -int ha_federated::index_end(void) -{ - DBUG_ENTER("ha_federated::index_end"); - if (stored_result) - { - mysql_free_result(stored_result); - stored_result= 0; - } - active_index= MAX_KEY; - DBUG_RETURN(0); -} - -/* - This is called for each row of the table scan. When you run out of records - you should return HA_ERR_END_OF_FILE. Fill buff up with the row information. - The Field structure for the table is the key to getting data into buf - in a manner that will allow the server to understand it. - - Called from filesort.cc, records.cc, sql_handler.cc, sql_select.cc, - sql_table.cc, and sql_update.cc. -*/ - -int ha_federated::rnd_next(byte *buf) -{ - DBUG_ENTER("ha_federated::rnd_next"); - - if (stored_result == 0) - { - /* - Return value of rnd_init is not always checked (see records.cc), - so we can get here _even_ if there is _no_ pre-fetched result-set! - TODO: fix it. We can delete this in 5.1 when rnd_init() is checked. - */ - DBUG_RETURN(1); - } - DBUG_RETURN(read_next(buf, stored_result)); -} - - -/* - ha_federated::read_next - - reads from a result set and converts to mysql internal - format - - SYNOPSIS - field_in_record_is_null() - buf byte pointer to record - result mysql result set - - DESCRIPTION - This method is a wrapper method that reads one record from a result - set and converts it to the internal table format - - RETURN VALUE - 1 error - 0 no error -*/ - -int ha_federated::read_next(byte *buf, MYSQL_RES *result) -{ - int retval; - MYSQL_ROW row; - DBUG_ENTER("ha_federated::read_next"); - - table->status= STATUS_NOT_FOUND; // For easier return - - /* Fetch a row, insert it back in a row format. */ - if (!(row= mysql_fetch_row(result))) - DBUG_RETURN(HA_ERR_END_OF_FILE); - - if (!(retval= convert_row_to_internal_format(buf, row, result))) - table->status= 0; - - DBUG_RETURN(retval); -} - - -/* - store reference to current row so that we can later find it for - a re-read, update or delete. - - In case of federated, a reference is either a primary key or - the whole record. - - Called from filesort.cc, sql_select.cc, sql_delete.cc and sql_update.cc. -*/ - -void ha_federated::position(const byte *record) -{ - DBUG_ENTER("ha_federated::position"); - if (table->s->primary_key != MAX_KEY) - key_copy(ref, (byte *)record, table->key_info + table->s->primary_key, - ref_length); - else - memcpy(ref, record, ref_length); - DBUG_VOID_RETURN; -} - - -/* - This is like rnd_next, but you are given a position to use to determine the - row. The position will be of the type that you stored in ref. - - This method is required for an ORDER BY - - Called from filesort.cc records.cc sql_insert.cc sql_select.cc sql_update.cc. -*/ - -int ha_federated::rnd_pos(byte *buf, byte *pos) -{ - int result; - DBUG_ENTER("ha_federated::rnd_pos"); - statistic_increment(table->in_use->status_var.ha_read_rnd_count, - &LOCK_status); - if (table->s->primary_key != MAX_KEY) - { - /* We have a primary key, so use index_read_idx to find row */ - result= index_read_idx(buf, table->s->primary_key, pos, - ref_length, HA_READ_KEY_EXACT); - } - else - { - /* otherwise, get the old record ref as obtained in ::position */ - memcpy(buf, pos, ref_length); - result= 0; - } - table->status= result ? STATUS_NOT_FOUND : 0; - DBUG_RETURN(result); -} - - -/* - ::info() is used to return information to the optimizer. - Currently this table handler doesn't implement most of the fields - really needed. SHOW also makes use of this data - Another note, you will probably want to have the following in your - code: - if (records < 2) - records = 2; - The reason is that the server will optimize for cases of only a single - record. If in a table scan you don't know the number of records - it will probably be better to set records to two so you can return - as many records as you need. - Along with records a few more variables you may wish to set are: - records - deleted - data_file_length - index_file_length - delete_length - check_time - Take a look at the public variables in handler.h for more information. - - Called in: - filesort.cc - ha_heap.cc - item_sum.cc - opt_sum.cc - sql_delete.cc - sql_delete.cc - sql_derived.cc - sql_select.cc - sql_select.cc - sql_select.cc - sql_select.cc - sql_select.cc - sql_show.cc - sql_show.cc - sql_show.cc - sql_show.cc - sql_table.cc - sql_union.cc - sql_update.cc - -*/ - -int ha_federated::info(uint flag) -{ - char error_buffer[FEDERATED_QUERY_BUFFER_SIZE]; - char status_buf[FEDERATED_QUERY_BUFFER_SIZE]; - int error; - uint error_code; - MYSQL_RES *result= 0; - MYSQL_ROW row; - String status_query_string(status_buf, sizeof(status_buf), &my_charset_bin); - DBUG_ENTER("ha_federated::info"); - - error_code= ER_QUERY_ON_FOREIGN_DATA_SOURCE; - /* we want not to show table status if not needed to do so */ - if (flag & (HA_STATUS_VARIABLE | HA_STATUS_CONST)) - { - status_query_string.length(0); - status_query_string.append(FEDERATED_INFO); - append_ident(&status_query_string, share->table_name, - share->table_name_length, value_quote_char); - - if (real_query(status_query_string.ptr(), status_query_string.length())) - goto error; - - status_query_string.length(0); - - result= mysql_store_result(mysql); - - /* - We're going to use fields num. 4, 12 and 13 of the resultset, - so make sure we have these fields. - */ - if (!result || (mysql_num_fields(result) < 14)) - goto error; - - if (!mysql_num_rows(result)) - goto error; - - if (!(row= mysql_fetch_row(result))) - goto error; - - if (flag & HA_STATUS_VARIABLE | HA_STATUS_CONST) - { - /* - deleted is set in ha_federated::info - */ - /* - need to figure out what this means as far as federated is concerned, - since we don't have a "file" - - data_file_length = ? - index_file_length = ? - delete_length = ? - */ - if (row[4] != NULL) - records= (ha_rows) my_strtoll10(row[4], (char**) 0, &error); - - mean_rec_length= table->s->reclength; - data_file_length= records * mean_rec_length; - - if (row[12] != NULL) - update_time= (time_t) my_strtoll10(row[12], (char**) 0, &error); - if (row[13] != NULL) - check_time= (time_t) my_strtoll10(row[13], (char**) 0, &error); - } - - /* - size of IO operations (This is based on a good guess, no high science - involved) - */ - block_size= 4096; - } - - if (flag & HA_STATUS_AUTO) - auto_increment_value= mysql->last_used_con->insert_id; - - mysql_free_result(result); - - DBUG_RETURN(0); - -error: - mysql_free_result(result); - if (mysql) - { - my_sprintf(error_buffer, (error_buffer, ": %d : %s", - mysql_errno(mysql), mysql_error(mysql))); - my_error(error_code, MYF(0), error_buffer); - } - else - if (remote_error_number != -1 /* error already reported */) - { - error_code= remote_error_number; - my_error(error_code, MYF(0), ER(error_code)); - } - DBUG_RETURN(error_code); -} - - -/** - @brief Handles extra signals from MySQL server - - @param[in] operation Hint for storage engine - - @return Operation Status - @retval 0 OK - */ -int ha_federated::extra(ha_extra_function operation) -{ - DBUG_ENTER("ha_federated::extra"); - switch (operation) { - case HA_EXTRA_IGNORE_DUP_KEY: - ignore_duplicates= TRUE; - break; - case HA_EXTRA_NO_IGNORE_DUP_KEY: - insert_dup_update= FALSE; - ignore_duplicates= FALSE; - break; - case HA_EXTRA_WRITE_CAN_REPLACE: - replace_duplicates= TRUE; - break; - case HA_EXTRA_WRITE_CANNOT_REPLACE: - /* - We use this flag to ensure that we do not create an "INSERT IGNORE" - statement when inserting new rows into the remote table. - */ - replace_duplicates= FALSE; - break; - case HA_EXTRA_INSERT_WITH_UPDATE: - insert_dup_update= TRUE; - break; - case HA_EXTRA_RESET: - insert_dup_update= FALSE; - ignore_duplicates= FALSE; - replace_duplicates= FALSE; - break; - default: - /* do nothing */ - DBUG_PRINT("info",("unhandled operation: %d", (uint) operation)); - } - DBUG_RETURN(0); -} - - -/* - Used to delete all rows in a table. Both for cases of truncate and - for cases where the optimizer realizes that all rows will be - removed as a result of a SQL statement. - - Called from item_sum.cc by Item_func_group_concat::clear(), - Item_sum_count_distinct::clear(), and Item_func_group_concat::clear(). - Called from sql_delete.cc by mysql_delete(). - Called from sql_select.cc by JOIN::reinit(). - Called from sql_union.cc by st_select_lex_unit::exec(). -*/ - -int ha_federated::delete_all_rows() -{ - char query_buffer[FEDERATED_QUERY_BUFFER_SIZE]; - String query(query_buffer, sizeof(query_buffer), &my_charset_bin); - DBUG_ENTER("ha_federated::delete_all_rows"); - - query.length(0); - - query.set_charset(system_charset_info); - query.append(FEDERATED_TRUNCATE); - append_ident(&query, share->table_name, share->table_name_length, - ident_quote_char); - - /* - TRUNCATE won't return anything in mysql_affected_rows - */ - if (real_query(query.ptr(), query.length())) - { - DBUG_RETURN(stash_remote_error()); - } - deleted+= records; - records= 0; - DBUG_RETURN(0); -} - - -/* - The idea with handler::store_lock() is the following: - - The statement decided which locks we should need for the table - for updates/deletes/inserts we get WRITE locks, for SELECT... we get - read locks. - - Before adding the lock into the table lock handler (see thr_lock.c) - mysqld calls store lock with the requested locks. Store lock can now - modify a write lock to a read lock (or some other lock), ignore the - lock (if we don't want to use MySQL table locks at all) or add locks - for many tables (like we do when we are using a MERGE handler). - - Berkeley DB for federated changes all WRITE locks to TL_WRITE_ALLOW_WRITE - (which signals that we are doing WRITES, but we are still allowing other - reader's and writer's. - - When releasing locks, store_lock() are also called. In this case one - usually doesn't have to do anything. - - In some exceptional cases MySQL may send a request for a TL_IGNORE; - This means that we are requesting the same lock as last time and this - should also be ignored. (This may happen when someone does a flush - table when we have opened a part of the tables, in which case mysqld - closes and reopens the tables and tries to get the same locks at last - time). In the future we will probably try to remove this. - - Called from lock.cc by get_lock_data(). -*/ - -THR_LOCK_DATA **ha_federated::store_lock(THD *thd, - THR_LOCK_DATA **to, - enum thr_lock_type lock_type) -{ - DBUG_ENTER("ha_federated::store_lock"); - if (lock_type != TL_IGNORE && lock.type == TL_UNLOCK) - { - /* - Here is where we get into the guts of a row level lock. - If TL_UNLOCK is set - If we are not doing a LOCK TABLE or DISCARD/IMPORT - TABLESPACE, then allow multiple writers - */ - - if ((lock_type >= TL_WRITE_CONCURRENT_INSERT && - lock_type <= TL_WRITE) && !thd->in_lock_tables) - lock_type= TL_WRITE_ALLOW_WRITE; - - /* - In queries of type INSERT INTO t1 SELECT ... FROM t2 ... - MySQL would use the lock TL_READ_NO_INSERT on t2, and that - would conflict with TL_WRITE_ALLOW_WRITE, blocking all inserts - to t2. Convert the lock to a normal read lock to allow - concurrent inserts to t2. - */ - - if (lock_type == TL_READ_NO_INSERT && !thd->in_lock_tables) - lock_type= TL_READ; - - lock.type= lock_type; - } - - *to++= &lock; - - DBUG_RETURN(to); -} - -/* - create() does nothing, since we have no local setup of our own. - FUTURE: We should potentially connect to the foreign database and -*/ - -int ha_federated::create(const char *name, TABLE *table_arg, - HA_CREATE_INFO *create_info) -{ - int retval; - FEDERATED_SHARE tmp_share; // Only a temporary share, to test the url - DBUG_ENTER("ha_federated::create"); - - retval= parse_url(&tmp_share, table_arg, 1); - - my_free((gptr) tmp_share.scheme, MYF(MY_ALLOW_ZERO_PTR)); - DBUG_RETURN(retval); - -} - - -int ha_federated::real_connect() -{ - char buffer[FEDERATED_QUERY_BUFFER_SIZE]; - String sql_query(buffer, sizeof(buffer), &my_charset_bin); - DBUG_ENTER("ha_federated::real_connect"); - - /* - Bug#25679 - Ensure that we do not hold the LOCK_open mutex while attempting - to establish Federated connection to guard against a trivial - Denial of Service scenerio. - */ - safe_mutex_assert_not_owner(&LOCK_open); - - DBUG_ASSERT(mysql == NULL); - - if (!(mysql= mysql_init(NULL))) - { - remote_error_number= HA_ERR_OUT_OF_MEM; - DBUG_RETURN(-1); - } - - /* - BUG# 17044 Federated Storage Engine is not UTF8 clean - Add set names to whatever charset the table is at open - of table - */ - /* this sets the csname like 'set names utf8' */ - mysql_options(mysql,MYSQL_SET_CHARSET_NAME, - this->table->s->table_charset->csname); - - sql_query.length(0); - - if (!mysql_real_connect(mysql, - share->hostname, - share->username, - share->password, - share->database, - share->port, - share->socket, 0)) - { - stash_remote_error(); - mysql_close(mysql); - mysql= NULL; - my_error(ER_CONNECT_TO_FOREIGN_DATA_SOURCE, MYF(0), remote_error_buf); - remote_error_number= -1; - DBUG_RETURN(-1); - } - - /* - We have established a connection, lets try a simple dummy query just - to check that the table and expected columns are present. - */ - sql_query.append(share->select_query); - sql_query.append(FEDERATED_WHERE); - sql_query.append(FEDERATED_FALSE); - if (mysql_real_query(mysql, sql_query.ptr(), sql_query.length())) - { - sql_query.length(0); - sql_query.append("error: "); - sql_query.qs_append(mysql_errno(mysql)); - sql_query.append(" '"); - sql_query.append(mysql_error(mysql)); - sql_query.append("'"); - mysql_close(mysql); - mysql= NULL; - my_error(ER_FOREIGN_DATA_SOURCE_DOESNT_EXIST, MYF(0), sql_query.ptr()); - remote_error_number= -1; - DBUG_RETURN(-1); - } - - /* Just throw away the result, no rows anyways but need to keep in sync */ - mysql_free_result(mysql_store_result(mysql)); - - /* - Since we do not support transactions at this version, we can let the client - API silently reconnect. For future versions, we will need more logic to - deal with transactions - */ - - mysql->reconnect= 1; - DBUG_RETURN(0); -} - - -int ha_federated::real_query(const char *query, uint length) -{ - int rc= 0; - DBUG_ENTER("ha_federated::real_query"); - - if (!mysql && (rc= real_connect())) - goto end; - - if (!query || !length) - goto end; - - rc= mysql_real_query(mysql, query, length); - -end: - DBUG_RETURN(rc); -} - - -int ha_federated::stash_remote_error() -{ - DBUG_ENTER("ha_federated::stash_remote_error()"); - if (!mysql) - DBUG_RETURN(remote_error_number); - remote_error_number= mysql_errno(mysql); - strmake(remote_error_buf, mysql_error(mysql), sizeof(remote_error_buf)-1); - if (remote_error_number == ER_DUP_ENTRY || - remote_error_number == ER_DUP_KEY) - DBUG_RETURN(HA_ERR_FOUND_DUPP_KEY); - DBUG_RETURN(HA_FEDERATED_ERROR_WITH_REMOTE_SYSTEM); -} - - -bool ha_federated::get_error_message(int error, String* buf) -{ - DBUG_ENTER("ha_federated::get_error_message"); - DBUG_PRINT("enter", ("error: %d", error)); - if (error == HA_FEDERATED_ERROR_WITH_REMOTE_SYSTEM) - { - buf->append(STRING_WITH_LEN("Error on remote system: ")); - buf->qs_append(remote_error_number); - buf->append(STRING_WITH_LEN(": ")); - buf->append(remote_error_buf); - - remote_error_number= 0; - remote_error_buf[0]= '\0'; - } - DBUG_PRINT("exit", ("message: %s", buf->ptr())); - DBUG_RETURN(FALSE); -} - -#endif /* HAVE_FEDERATED_DB */ |