~drizzle-trunk/drizzle/development

/******************************************************

Smart ALTER TABLE

(c) 2005-2008 Innobase Oy

*******************************************************/

#include <mysql_priv.h>

#include <mysqld_error.h>

extern "C" {

#include "log0log.h"

#include "row0merge.h"

#include "srv0srv.h"

#include "trx0trx.h"

#include "trx0roll.h"

#include "ha_prototypes.h"

#include "handler0alter.h"

}

#include "ha_innodb.h"

#include "handler0vars.h"

/*****************************************************************

Copies an InnoDB column to a MySQL field.  This function is

adapted from row_sel_field_store_in_mysql_format(). */

static

void

innobase_col_to_mysql(

/*==================*/

	const dict_col_t*	col,	/* in: InnoDB column */

	const uchar*		data,	/* in: InnoDB column data */

	ulint			len,	/* in: length of data, in bytes */

	Field*			field)	/* in/out: MySQL field */

{

	uchar*	ptr;

	uchar*	dest	= field->ptr;

	ulint	flen	= field->pack_length();

	switch (col->mtype) {

	case DATA_INT:

		ut_ad(len == flen);

		/* Convert integer data from Innobase to little-endian

		format, sign bit restored to normal */

		for (ptr = dest + len; ptr != dest; ) {

			*--ptr = *data++;

		}

		if (!(field->flags & UNSIGNED_FLAG)) {

			((byte*) dest)[len - 1] ^= 0x80;

		}

		break;

	case DATA_VARCHAR:

	case DATA_VARMYSQL:

	case DATA_BINARY:

		field->reset();

		if (field->type() == MYSQL_TYPE_VARCHAR) {

			/* This is a >= 5.0.3 type true VARCHAR. Store the

			length of the data to the first byte or the first

			two bytes of dest. */

			dest = row_mysql_store_true_var_len(

				dest, len, flen - field->key_length());

		}

		/* Copy the actual data */

		memcpy(dest, data, len);

		break;

	case DATA_BLOB:

		/* Store a pointer to the BLOB buffer to dest: the BLOB was

		already copied to the buffer in row_sel_store_mysql_rec */

		row_mysql_store_blob_ref(dest, flen, data, len);

		break;

#ifdef UNIV_DEBUG

	case DATA_MYSQL:

		ut_ad(flen >= len);

		ut_ad(col->mbmaxlen >= col->mbminlen);

		ut_ad(col->mbmaxlen > col->mbminlen || flen == len);

		memcpy(dest, data, len);

		break;

	default:

	case DATA_SYS_CHILD:

	case DATA_SYS:

		/* These column types should never be shipped to MySQL. */

		ut_ad(0);

	case DATA_CHAR:

	case DATA_FIXBINARY:

	case DATA_FLOAT:

	case DATA_DOUBLE:

	case DATA_DECIMAL:

		/* Above are the valid column types for MySQL data. */

		ut_ad(flen == len);

#else /* UNIV_DEBUG */

	default:

#endif /* UNIV_DEBUG */

		memcpy(dest, data, len);

	}

}

/*****************************************************************

Copies an InnoDB record to table->record[0]. */

extern "C" UNIV_INTERN

void

innobase_rec_to_mysql(

/*==================*/

	TABLE*			table,		/* in/out: MySQL table */

	const rec_t*		rec,		/* in: record */

	const dict_index_t*	index,		/* in: index */

	const ulint*		offsets)	/* in: rec_get_offsets(

						rec, index, ...) */

{

	uint	n_fields	= table->s->fields;

	uint	i;

	ut_ad(n_fields == dict_table_get_n_user_cols(index->table));

	for (i = 0; i < n_fields; i++) {

		Field*		field	= table->field[i];

		ulint		ipos;

		ulint		ilen;

		const uchar*	ifield;

		field->reset();

		ipos = dict_index_get_nth_col_pos(index, i);

		if (UNIV_UNLIKELY(ipos == ULINT_UNDEFINED)) {

null_field:

			field->set_null();

			continue;

		}

		ifield = rec_get_nth_field(rec, offsets, ipos, &ilen);

		/* Assign the NULL flag */

		if (ilen == UNIV_SQL_NULL) {

			ut_ad(field->real_maybe_null());

			goto null_field;

		}

		field->set_notnull();

		innobase_col_to_mysql(

			dict_field_get_col(

				dict_index_get_nth_field(index, ipos)),

			ifield, ilen, field);

	}

}

/*****************************************************************

Resets table->record[0]. */

extern "C" UNIV_INTERN

void

innobase_rec_reset(

/*===============*/

	TABLE*			table)		/* in/out: MySQL table */

{

	uint	n_fields	= table->s->fields;

	uint	i;

	for (i = 0; i < n_fields; i++) {

		table->field[i]->set_default();

	}

}

/**********************************************************************

Removes the filename encoding of a database and table name. */

static

void

innobase_convert_tablename(

/*=======================*/

	char*	s)	/* in: identifier; out: decoded identifier */

{

	uint	errors;

	char*	slash = strchr(s, '/');

	if (slash) {

		char*	t;

		/* Temporarily replace the '/' with NUL. */

		*slash = 0;

		/* Convert the database name. */

		strconvert(&my_charset_filename, s, system_charset_info,

			   s, slash - s + 1, &errors);

		t = s + strlen(s);

		ut_ad(slash >= t);

		/* Append a  '.' after the database name. */

		*t++ = '.';

		slash++;

		/* Convert the table name. */

		strconvert(&my_charset_filename, slash, system_charset_info,

			   t, slash - t + strlen(slash), &errors);

	} else {

		strconvert(&my_charset_filename, s,

			   system_charset_info, s, strlen(s), &errors);

	}

}

/***********************************************************************

This function checks that index keys are sensible. */

static

int

innobase_check_index_keys(

/*======================*/

					/* out: 0 or error number */

	const KEY*	key_info,	/* in: Indexes to be created */

	ulint		num_of_keys)	/* in: Number of indexes to

					be created */

{

	ulint		key_num;

	ut_ad(key_info);

	ut_ad(num_of_keys);

	for (key_num = 0; key_num < num_of_keys; key_num++) {

		const KEY&	key = key_info[key_num];

		/* Check that the same index name does not appear

		twice in indexes to be created. */

		for (ulint i = 0; i < key_num; i++) {

			const KEY&	key2 = key_info[i];

			if (0 == strcmp(key.name, key2.name)) {

				errmsg_printf(ERRMSG_LVL_ERROR, "InnoDB: key name `%s` appears"

						" twice in CREATE INDEX\n",

						key.name);

				return(ER_WRONG_NAME_FOR_INDEX);

			}

		}

		/* Check that MySQL does not try to create a column

		prefix index field on an inappropriate data type and

		that the same colum does not appear twice in the index. */

		for (ulint i = 0; i < key.key_parts; i++) {

			const KEY_PART_INFO&	key_part1

				= key.key_part[i];

			const Field*		field

				= key_part1.field;

			ibool			is_unsigned;

			switch (get_innobase_type_from_mysql_type(

					&is_unsigned, field)) {

			default:

				break;

			case DATA_INT:

			case DATA_FLOAT:

			case DATA_DOUBLE:

			case DATA_DECIMAL:

				if (field->type() == MYSQL_TYPE_VARCHAR) {

					if (key_part1.length

					    >= field->pack_length()

					    - ((Field_varstring*) field)

					    ->length_bytes) {

						break;

					}

				} else {

					if (key_part1.length

					    >= field->pack_length()) {

						break;

					}

				}

				errmsg_printf(ERRMSG_LVL_ERROR, "InnoDB: MySQL is trying to"

						" create a column prefix"

						" index field on an"

						" inappropriate data type."

						" column `%s`,"

						" index `%s`.\n",

						field->field_name,

						key.name);

				return(ER_WRONG_KEY_COLUMN);

			}

			for (ulint j = 0; j < i; j++) {

				const KEY_PART_INFO&	key_part2

					= key.key_part[j];

				if (strcmp(key_part1.field->field_name,

					   key_part2.field->field_name)) {

					continue;

				}

				errmsg_printf(ERRMSG_LVL_ERROR, "InnoDB: column `%s`"

						" is not allowed to occur"

						" twice in index `%s`.\n",

						key_part1.field->field_name,

						key.name);

				return(ER_WRONG_KEY_COLUMN);

			}

		}

	}

	return(0);

}

/***********************************************************************

Create index field definition for key part */

static

void

innobase_create_index_field_def(

/*============================*/

	KEY_PART_INFO*		key_part,	/* in: MySQL key definition */

	mem_heap_t*		heap,		/* in: memory heap */

	merge_index_field_t*	index_field)	/* out: index field

						definition for key_part */

{

	Field*		field;

	ibool		is_unsigned;

	ulint		col_type;

	DBUG_ENTER("innobase_create_index_field_def");

	ut_ad(key_part);

	ut_ad(index_field);

	field = key_part->field;

	ut_a(field);

	col_type = get_innobase_type_from_mysql_type(&is_unsigned, field);

	if (DATA_BLOB == col_type

	    || (key_part->length < field->pack_length()

		&& field->type() != MYSQL_TYPE_VARCHAR)

	    || (field->type() == MYSQL_TYPE_VARCHAR

		&& key_part->length < field->pack_length()

			- ((Field_varstring*)field)->length_bytes)) {

		index_field->prefix_len = key_part->length;

	} else {

		index_field->prefix_len = 0;

	}

	index_field->field_name = mem_heap_strdup(heap, field->field_name);

	DBUG_VOID_RETURN;

}

/***********************************************************************

Create index definition for key */

static

void

innobase_create_index_def(

/*======================*/

	KEY*			key,		/* in: key definition */

	bool			new_primary,	/* in: TRUE=generating

						a new primary key

						on the table */

	bool			key_primary,	/* in: TRUE if this key

						is a primary key */

	merge_index_def_t*	index,		/* out: index definition */

	mem_heap_t*		heap)		/* in: heap where memory

						is allocated */

{

	ulint	i;

	ulint	len;

	ulint	n_fields = key->key_parts;

	char*	index_name;

	DBUG_ENTER("innobase_create_index_def");

	index->fields = (merge_index_field_t*) mem_heap_alloc(

		heap, n_fields * sizeof *index->fields);

	index->ind_type = 0;

	index->n_fields = n_fields;

	len = strlen(key->name) + 1;

	index->name = index_name = (char*) mem_heap_alloc(heap,

							  len + !new_primary);

	if (UNIV_LIKELY(!new_primary)) {

		*index_name++ = TEMP_INDEX_PREFIX;

	}

	memcpy(index_name, key->name, len);

	if (key->flags & HA_NOSAME) {

		index->ind_type |= DICT_UNIQUE;

	}

	if (key_primary) {

		index->ind_type |= DICT_CLUSTERED;

	}

	for (i = 0; i < n_fields; i++) {

		innobase_create_index_field_def(&key->key_part[i], heap,

						&index->fields[i]);

	}

	DBUG_VOID_RETURN;

}

/***********************************************************************

Copy index field definition */

static

void

innobase_copy_index_field_def(

/*==========================*/

	const dict_field_t*	field,		/* in: definition to copy */

	merge_index_field_t*	index_field)	/* out: copied definition */

{

	DBUG_ENTER("innobase_copy_index_field_def");

	DBUG_ASSERT(field != NULL);

	DBUG_ASSERT(index_field != NULL);

	index_field->field_name = field->name;

	index_field->prefix_len = field->prefix_len;

	DBUG_VOID_RETURN;

}

/***********************************************************************

Copy index definition for the index */

static

void

innobase_copy_index_def(

/*====================*/

	const dict_index_t*	index,	/* in: index definition to copy */

	merge_index_def_t*	new_index,/* out: Index definition */

	mem_heap_t*		heap)	/* in: heap where allocated */

{

	ulint	n_fields;

	ulint	i;

	DBUG_ENTER("innobase_copy_index_def");

	/* Note that we take only those fields that user defined to be

	in the index.  In the internal representation more colums were

	added and those colums are not copied .*/

	n_fields = index->n_user_defined_cols;

	new_index->fields = (merge_index_field_t*) mem_heap_alloc(

		heap, n_fields * sizeof *new_index->fields);

	/* When adding a PRIMARY KEY, we may convert a previous

	clustered index to a secondary index (UNIQUE NOT NULL). */

	new_index->ind_type = index->type & ~DICT_CLUSTERED;

	new_index->n_fields = n_fields;

	new_index->name = index->name;

	for (i = 0; i < n_fields; i++) {

		innobase_copy_index_field_def(&index->fields[i],

					      &new_index->fields[i]);

	}

	DBUG_VOID_RETURN;

}

/***********************************************************************

Create an index table where indexes are ordered as follows:

IF a new primary key is defined for the table THEN

	1) New primary key

	2) Original secondary indexes

	3) New secondary indexes

ELSE

	1) All new indexes in the order they arrive from MySQL

ENDIF

*/

static

merge_index_def_t*

innobase_create_key_def(

/*====================*/

					/* out: key definitions or NULL */

	trx_t*		trx,		/* in: trx */

	const dict_table_t*table,		/* in: table definition */

	mem_heap_t*	heap,		/* in: heap where space for key

					definitions are allocated */

	KEY*		key_info,	/* in: Indexes to be created */

	ulint&		n_keys)		/* in/out: Number of indexes to

					be created */

{

	ulint			i = 0;

	merge_index_def_t*	indexdef;

	merge_index_def_t*	indexdefs;

	bool			new_primary;

	DBUG_ENTER("innobase_create_key_def");

	indexdef = indexdefs = (merge_index_def_t*)

		mem_heap_alloc(heap, sizeof *indexdef

			       * (n_keys + UT_LIST_GET_LEN(table->indexes)));

	/* If there is a primary key, it is always the first index

	defined for the table. */

	new_primary = !my_strcasecmp(system_charset_info,

				     key_info->name, "PRIMARY");

	/* If there is a UNIQUE INDEX consisting entirely of NOT NULL

	columns, MySQL will treat it as a PRIMARY KEY unless the

	table already has one. */

	if (!new_primary && (key_info->flags & HA_NOSAME)

	    && row_table_got_default_clust_index(table)) {

		uint	key_part = key_info->key_parts;

		new_primary = TRUE;

		while (key_part--) {

			if (key_info->key_part[key_part].key_type

			    & FIELDFLAG_MAYBE_NULL) {

				new_primary = FALSE;

				break;

			}

		}

	}

	if (new_primary) {

		const dict_index_t*	index;

		/* Create the PRIMARY key index definition */

		innobase_create_index_def(&key_info[i++], TRUE, TRUE,

					  indexdef++, heap);

		row_mysql_lock_data_dictionary(trx);

		index = dict_table_get_first_index(table);

		/* Copy the index definitions of the old table.  Skip

		the old clustered index if it is a generated clustered

		index or a PRIMARY KEY.  If the clustered index is a

		UNIQUE INDEX, it must be converted to a secondary index. */

		if (dict_index_get_nth_col(index, 0)->mtype == DATA_SYS

		    || !my_strcasecmp(system_charset_info,

				      index->name, "PRIMARY")) {

			index = dict_table_get_next_index(index);

		}

		while (index) {

			innobase_copy_index_def(index, indexdef++, heap);

			index = dict_table_get_next_index(index);

		}

		row_mysql_unlock_data_dictionary(trx);

	}

	/* Create definitions for added secondary indexes. */

	while (i < n_keys) {

		innobase_create_index_def(&key_info[i++], new_primary, FALSE,

					  indexdef++, heap);

	}

	n_keys = indexdef - indexdefs;

	DBUG_RETURN(indexdefs);

}

/***********************************************************************

Create a temporary tablename using query id, thread id, and id */

static

char*

innobase_create_temporary_tablename(

/*================================*/

					/* out: temporary tablename */

	mem_heap_t*	heap,		/* in: memory heap */

	char		id,		/* in: identifier [0-9a-zA-Z] */

	const char*     table_name)	/* in: table name */

{

	char*			name;

	ulint			len;

	static const char	suffix[] = "@0023 "; /* "# " */

	len = strlen(table_name);

	name = (char*) mem_heap_alloc(heap, len + sizeof suffix);

	memcpy(name, table_name, len);

	memcpy(name + len, suffix, sizeof suffix);

	name[len + (sizeof suffix - 2)] = id;

	return(name);

}

/***********************************************************************

Create indexes. */

UNIV_INTERN

int

ha_innobase::add_index(

/*===================*/

				/* out: 0 or error number */

	TABLE*	table,		/* in: Table where indexes are created */

	KEY*	key_info,	/* in: Indexes to be created */

	uint	num_of_keys)	/* in: Number of indexes to be created */

{

	dict_index_t**	index;		/* Index to be created */

	dict_table_t*	innodb_table;	/* InnoDB table in dictionary */

	dict_table_t*	indexed_table;	/* Table where indexes are created */

	merge_index_def_t* index_defs;	/* Index definitions */

	mem_heap_t*     heap;		/* Heap for index definitions */

	trx_t*		trx;		/* Transaction */

	ulint		num_of_idx;

	ulint		num_created	= 0;

	ibool		dict_locked	= FALSE;

	ulint		new_primary;

	ulint		error;

	DBUG_ENTER("ha_innobase::add_index");

	ut_a(table);

	ut_a(key_info);

	ut_a(num_of_keys);

	if (srv_created_new_raw || srv_force_recovery) {

		DBUG_RETURN(HA_ERR_WRONG_COMMAND);

	}

	update_thd();

	heap = mem_heap_create(1024);

	/* In case MySQL calls this in the middle of a SELECT query, release

	possible adaptive hash latch to avoid deadlocks of threads. */

	trx_search_latch_release_if_reserved(prebuilt->trx);

	/* Create a background transaction for the operations on

	the data dictionary tables. */

	trx = trx_allocate_for_mysql();

	trx_start_if_not_started(trx);

	trx->mysql_thd = user_thd;

	trx->mysql_query_str = thd_query(user_thd);

	innodb_table = indexed_table

		= dict_table_get(prebuilt->table->name, FALSE);

	/* Check that index keys are sensible */

	error = innobase_check_index_keys(key_info, num_of_keys);

	if (UNIV_UNLIKELY(error)) {

err_exit:

		mem_heap_free(heap);

		trx_general_rollback_for_mysql(trx, FALSE, NULL);

		trx_free_for_mysql(trx);

		trx_commit_for_mysql(prebuilt->trx);

		DBUG_RETURN(error);

	}

	/* Create table containing all indexes to be built in this

	alter table add index so that they are in the correct order

	in the table. */

	num_of_idx = num_of_keys;

	index_defs = innobase_create_key_def(

		trx, innodb_table, heap, key_info, num_of_idx);

	new_primary = DICT_CLUSTERED & index_defs[0].ind_type;

	/* Allocate memory for dictionary index definitions */

	index = (dict_index_t**) mem_heap_alloc(

		heap, num_of_idx * sizeof *index);

	/* Flag this transaction as a dictionary operation, so that

	the data dictionary will be locked in crash recovery. */

	trx_set_dict_operation(trx, TRX_DICT_OP_INDEX);

	/* Acquire a lock on the table before creating any indexes. */

	error = row_merge_lock_table(prebuilt->trx, innodb_table,

				     new_primary ? LOCK_X : LOCK_S);

	if (UNIV_UNLIKELY(error != DB_SUCCESS)) {

		goto error_handling;

	}

	/* Latch the InnoDB data dictionary exclusively so that no deadlocks

	or lock waits can happen in it during an index create operation. */

	row_mysql_lock_data_dictionary(trx);

	dict_locked = TRUE;

	/* If a new primary key is defined for the table we need

	to drop the original table and rebuild all indexes. */

	if (UNIV_UNLIKELY(new_primary)) {

		/* This transaction should be the only one

		operating on the table. */

		ut_a(innodb_table->n_mysql_handles_opened == 1);

		char*	new_table_name = innobase_create_temporary_tablename(

			heap, '1', innodb_table->name);

		/* Clone the table. */

		trx_set_dict_operation(trx, TRX_DICT_OP_TABLE);

		indexed_table = row_merge_create_temporary_table(

			new_table_name, index_defs, innodb_table, trx);

		if (!indexed_table) {

			switch (trx->error_state) {

			case DB_TABLESPACE_ALREADY_EXISTS:

			case DB_DUPLICATE_KEY:

				innobase_convert_tablename(new_table_name);

				my_error(HA_ERR_TABLE_EXIST, MYF(0),

					 new_table_name);

				error = HA_ERR_TABLE_EXIST;

				break;

			default:

				error = convert_error_code_to_mysql(

					trx->error_state, innodb_table->flags,

					user_thd);

			}

			row_mysql_unlock_data_dictionary(trx);

			goto err_exit;

		}

		trx->table_id = indexed_table->id;

	}

	/* Create the indexes in SYS_INDEXES and load into dictionary. */

	for (ulint i = 0; i < num_of_idx; i++) {

		index[i] = row_merge_create_index(trx, indexed_table,

						  &index_defs[i]);

		if (!index[i]) {

			error = trx->error_state;

			goto error_handling;

		}

		num_created++;

	}

	ut_ad(error == DB_SUCCESS);

	/* Commit the data dictionary transaction in order to release

	the table locks on the system tables.  Unfortunately, this

	means that if MySQL crashes while creating a new primary key

	inside row_merge_build_indexes(), indexed_table will not be

	dropped on crash recovery.  Thus, it will become orphaned. */

	trx_commit_for_mysql(trx);

	row_mysql_unlock_data_dictionary(trx);

	dict_locked = FALSE;

	ut_a(trx->n_active_thrs == 0);

	ut_a(UT_LIST_GET_LEN(trx->signals) == 0);

	if (UNIV_UNLIKELY(new_primary)) {

		/* A primary key is to be built.  Acquire an exclusive

		table lock also on the table that is being created. */

		ut_ad(indexed_table != innodb_table);

		error = row_merge_lock_table(prebuilt->trx, indexed_table,

					     LOCK_X);

		if (UNIV_UNLIKELY(error != DB_SUCCESS)) {

			goto error_handling;

		}

	}

	/* Read the clustered index of the table and build indexes

	based on this information using temporary files and merge sort. */

	error = row_merge_build_indexes(prebuilt->trx,

					innodb_table, indexed_table,

					index, num_of_idx, table);

error_handling:

#ifdef UNIV_DEBUG

	/* TODO: At the moment we can't handle the following statement

	in our debugging code below:

	alter table t drop index b, add index (b);

	The fix will have to parse the SQL and note that the index

	being added has the same name as the the one being dropped and

	ignore that in the dup index check.*/

	//dict_table_check_for_dup_indexes(prebuilt->table);

#endif

	/* After an error, remove all those index definitions from the

	dictionary which were defined. */

	switch (error) {

		const char*	old_name;

		char*		tmp_name;

	case DB_SUCCESS:

		ut_a(!dict_locked);

		row_mysql_lock_data_dictionary(trx);

		dict_locked = TRUE;

		if (!new_primary) {

			error = row_merge_rename_indexes(trx, indexed_table);

			if (error != DB_SUCCESS) {

				row_merge_drop_indexes(trx, indexed_table,

						       index, num_created);

			}

			goto convert_error;

		}

		/* If a new primary key was defined for the table and

		there was no error at this point, we can now rename

		the old table as a temporary table, rename the new

		temporary table as the old table and drop the old table. */

		old_name = innodb_table->name;

		tmp_name = innobase_create_temporary_tablename(heap, '2',

							       old_name);

		error = row_merge_rename_tables(innodb_table, indexed_table,

						tmp_name, trx);

		if (error != DB_SUCCESS) {

			row_merge_drop_table(trx, indexed_table);

			switch (error) {

			case DB_TABLESPACE_ALREADY_EXISTS:

			case DB_DUPLICATE_KEY:

				innobase_convert_tablename(tmp_name);

				my_error(HA_ERR_TABLE_EXIST, MYF(0), tmp_name);

				error = HA_ERR_TABLE_EXIST;

				break;

			default:

				goto convert_error;

			}

			break;

		}

		trx_commit_for_mysql(prebuilt->trx);

		row_prebuilt_free(prebuilt, TRUE);

		prebuilt = row_create_prebuilt(indexed_table);

		indexed_table->n_mysql_handles_opened++;

		error = row_merge_drop_table(trx, innodb_table);

		goto convert_error;

	case DB_TOO_BIG_RECORD:

		my_error(HA_ERR_TO_BIG_ROW, MYF(0));

		goto error;

	case DB_PRIMARY_KEY_IS_NULL:

		my_error(ER_PRIMARY_CANT_HAVE_NULL, MYF(0));

		/* fall through */