dict0dict.c

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

/**********************************************************************
Data dictionary system

(c) 1996 Innobase Oy

Created 1/8/1996 Heikki Tuuri
***********************************************************************/

#include "dict0dict.h"

#ifdef UNIV_NONINL
#include "dict0dict.ic"
#endif

#include "buf0buf.h"
#include "data0type.h"
#include "mach0data.h"
#include "dict0boot.h"
#include "dict0mem.h"
#include "dict0crea.h"
#include "trx0undo.h"
#include "btr0btr.h"
#include "btr0cur.h"
#include "btr0sea.h"
#include "pars0pars.h"
#include "pars0sym.h"
#include "que0que.h"
#include "rem0cmp.h"

dict_sys_t*	dict_sys	= NULL;	/* the dictionary system */

rw_lock_t	dict_operation_lock;	/* table create, drop, etc. reserve
					this in X-mode; implicit or backround
					operations purge, rollback, foreign
					key checks reserve this in S-mode; we
					cannot trust that MySQL protects
					implicit or background operations
					a table drop since MySQL does not
					know of them; therefore we need this;
					NOTE: a transaction which reserves
					this must keep book on the mode in
					trx->dict_operation_lock_mode */

#define	DICT_HEAP_SIZE		100	/* initial memory heap size when
					creating a table or index object */
#define DICT_POOL_PER_TABLE_HASH 512	/* buffer pool max size per table
					hash table fixed size in bytes */
#define DICT_POOL_PER_COL_HASH	128	/* buffer pool max size per column
					hash table fixed size in bytes */
#define DICT_POOL_PER_VARYING	4	/* buffer pool max size per data
					dictionary varying size in bytes */

/* Identifies generated InnoDB foreign key names */
static char	dict_ibfk[] = "_ibfk_";

#ifndef UNIV_HOTBACKUP
/**********************************************************************
Compares NUL-terminated UTF-8 strings case insensitively.

NOTE: the prototype of this function is copied from ha_innodb.cc! If you change
this function, you MUST change also the prototype here! */
extern
int
innobase_strcasecmp(
/*================*/
				/* out: 0 if a=b, <0 if a<b, >1 if a>b */
	const char*	a,	/* in: first string to compare */
	const char*	b);	/* in: second string to compare */

/**********************************************************************
Makes all characters in a NUL-terminated UTF-8 string lower case.

NOTE: the prototype of this function is copied from ha_innodb.cc! If you change
this function, you MUST change also the prototype here! */
extern
void
innobase_casedn_str(
/*================*/
	char*	a);	/* in/out: string to put in lower case */
#endif /* !UNIV_HOTBACKUP */

/**************************************************************************
Adds a column to the data dictionary hash table. */
static
void
dict_col_add_to_cache(
/*==================*/
	dict_table_t*	table,	/* in: table */
	dict_col_t*	col);	/* in: column */
/**************************************************************************
Repositions a column in the data dictionary hash table when the table name
changes. */
static
void
dict_col_reposition_in_cache(
/*=========================*/
	dict_table_t*	table,		/* in: table */
	dict_col_t*	col,		/* in: column */
	const char*	new_name);	/* in: new table name */
/**************************************************************************
Removes a column from the data dictionary hash table. */
static
void
dict_col_remove_from_cache(
/*=======================*/
	dict_table_t*	table,	/* in: table */
	dict_col_t*	col);	/* in: column */
/**************************************************************************
Removes an index from the dictionary cache. */
static
void
dict_index_remove_from_cache(
/*=========================*/
	dict_table_t*	table,	/* in: table */
	dict_index_t*	index);	/* in, own: index */
/***********************************************************************
Copies fields contained in index2 to index1. */
static
void
dict_index_copy(
/*============*/
	dict_index_t*	index1,	/* in: index to copy to */
	dict_index_t*	index2,	/* in: index to copy from */
	ulint		start,	/* in: first position to copy */
	ulint		end);	/* in: last position to copy */
/***********************************************************************
Tries to find column names for the index in the column hash table and
sets the col field of the index. */
static
ibool
dict_index_find_cols(
/*=================*/
				/* out: TRUE if success */
	dict_table_t*	table,	/* in: table */
	dict_index_t*	index);	/* in: index */	
/***********************************************************************
Builds the internal dictionary cache representation for a clustered
index, containing also system fields not defined by the user. */
static
dict_index_t*
dict_index_build_internal_clust(
/*============================*/
				/* out, own: the internal representation
				of the clustered index */
	dict_table_t*	table,	/* in: table */
	dict_index_t*	index);	/* in: user representation of a clustered
				index */	
/***********************************************************************
Builds the internal dictionary cache representation for a non-clustered
index, containing also system fields not defined by the user. */
static
dict_index_t*
dict_index_build_internal_non_clust(
/*================================*/
				/* out, own: the internal representation
				of the non-clustered index */
	dict_table_t*	table,	/* in: table */
	dict_index_t*	index);	/* in: user representation of a non-clustered
				index */	
/**************************************************************************
Removes a foreign constraint struct from the dictionary cache. */
static
void
dict_foreign_remove_from_cache(
/*===========================*/
	dict_foreign_t*	foreign);	/* in, own: foreign constraint */
/**************************************************************************
Prints a column data. */
static
void
dict_col_print_low(
/*===============*/
	dict_col_t*	col);	/* in: column */
/**************************************************************************
Prints an index data. */
static
void
dict_index_print_low(
/*=================*/
	dict_index_t*	index);	/* in: index */
/**************************************************************************
Prints a field data. */
static
void
dict_field_print_low(
/*=================*/
	dict_field_t*	field);	/* in: field */
/*************************************************************************
Frees a foreign key struct. */
static
void
dict_foreign_free(
/*==============*/
	dict_foreign_t*	foreign);	/* in, own: foreign key struct */

/* Stream for storing detailed information about the latest foreign key
and unique key errors */
FILE*	dict_foreign_err_file		= NULL;
mutex_t	dict_foreign_err_mutex; 	/* mutex protecting the foreign
					and unique error buffers */
	
/**********************************************************************
Makes all characters in a NUL-terminated UTF-8 string lower case. */

void
dict_casedn_str(
/*============*/
	char*	a)	/* in/out: string to put in lower case */
{
	innobase_casedn_str(a);
}

/************************************************************************
Checks if the database name in two table names is the same. */

ibool
dict_tables_have_same_db(
/*=====================*/
				/* out: TRUE if same db name */
	const char*	name1,	/* in: table name in the form
				dbname '/' tablename */
	const char*	name2)	/* in: table name in the form
				dbname '/' tablename */
{
	for (; *name1 == *name2; name1++, name2++) {
		if (*name1 == '/') {
			return(TRUE);
		}
		ut_a(*name1); /* the names must contain '/' */
	}
	return(FALSE);
}

/************************************************************************
Return the end of table name where we have removed dbname and '/'. */
static
const char*
dict_remove_db_name(
/*================*/
				/* out: table name */
	const char*	name)	/* in: table name in the form
				dbname '/' tablename */
{
	const char*	s;
	s = strchr(name, '/');
	ut_a(s);
	if (s) s++;
	return(s);
}

/************************************************************************
Get the database name length in a table name. */

ulint
dict_get_db_name_len(
/*=================*/
				/* out: database name length */
	const char*	name)	/* in: table name in the form
				dbname '/' tablename */
{
	const char*	s;
	s = strchr(name, '/');
	ut_a(s);
	return(s - name);
}
	
/************************************************************************
Reserves the dictionary system mutex for MySQL. */

void
dict_mutex_enter_for_mysql(void)
/*============================*/
{
	mutex_enter(&(dict_sys->mutex));
}
	
/************************************************************************
Releases the dictionary system mutex for MySQL. */

void
dict_mutex_exit_for_mysql(void)
/*===========================*/
{
	mutex_exit(&(dict_sys->mutex));
}
	
/************************************************************************
Decrements the count of open MySQL handles to a table. */

void
dict_table_decrement_handle_count(
/*==============================*/
	dict_table_t*	table)	/* in: table */
{
	mutex_enter(&(dict_sys->mutex));

	ut_a(table->n_mysql_handles_opened > 0);

	table->n_mysql_handles_opened--;
	
	mutex_exit(&(dict_sys->mutex));
}

/************************************************************************
Gets the nth column of a table. */

dict_col_t*
dict_table_get_nth_col_noninline(
/*=============================*/
				/* out: pointer to column object */
	dict_table_t*	table,	/* in: table */
	ulint		pos)	/* in: position of column */
{
	return(dict_table_get_nth_col(table, pos));
}

/************************************************************************
Gets the first index on the table (the clustered index). */

dict_index_t*
dict_table_get_first_index_noninline(
/*=================================*/
				/* out: index, NULL if none exists */
	dict_table_t*	table)	/* in: table */
{
	return(dict_table_get_first_index(table));
}

/************************************************************************
Gets the next index on the table. */

dict_index_t*
dict_table_get_next_index_noninline(
/*================================*/
				/* out: index, NULL if none left */
	dict_index_t*	index)	/* in: index */
{
	return(dict_table_get_next_index(index));
}

/**************************************************************************
Returns an index object. */

dict_index_t*
dict_table_get_index_noninline(
/*===========================*/
				/* out: index, NULL if does not exist */
	dict_table_t*	table,	/* in: table */
	const char*	name)	/* in: index name */
{
	return(dict_table_get_index(table, name));
}
	
/************************************************************************
Initializes the autoinc counter. It is not an error to initialize an already
initialized counter. */

void
dict_table_autoinc_initialize(
/*==========================*/
	dict_table_t*	table,	/* in: table */
	ib_longlong	value)	/* in: next value to assign to a row */
{
	mutex_enter(&(table->autoinc_mutex));

	table->autoinc_inited = TRUE;
	table->autoinc = value;

	mutex_exit(&(table->autoinc_mutex));
}

/************************************************************************
Gets the next autoinc value (== autoinc counter value), 0 if not yet
initialized. If initialized, increments the counter by 1. */

ib_longlong
dict_table_autoinc_get(
/*===================*/
				/* out: value for a new row, or 0 */
	dict_table_t*	table)	/* in: table */
{
	ib_longlong	value;

	mutex_enter(&(table->autoinc_mutex));

	if (!table->autoinc_inited) {

		value = 0;
	} else {
		value = table->autoinc;
		table->autoinc = table->autoinc + 1;
	}
	
	mutex_exit(&(table->autoinc_mutex));

	return(value);
}

/************************************************************************
Decrements the autoinc counter value by 1. */

void
dict_table_autoinc_decrement(
/*=========================*/
	dict_table_t*	table)	/* in: table */
{
	mutex_enter(&(table->autoinc_mutex));

	table->autoinc = table->autoinc - 1;
	
	mutex_exit(&(table->autoinc_mutex));
}

/************************************************************************
Reads the next autoinc value (== autoinc counter value), 0 if not yet
initialized. */

ib_longlong
dict_table_autoinc_read(
/*====================*/
				/* out: value for a new row, or 0 */
	dict_table_t*	table)	/* in: table */
{
	ib_longlong	value;

	mutex_enter(&(table->autoinc_mutex));

	if (!table->autoinc_inited) {

		value = 0;
	} else {
		value = table->autoinc;
	}
	
	mutex_exit(&(table->autoinc_mutex));

	return(value);
}

/************************************************************************
Peeks the autoinc counter value, 0 if not yet initialized. Does not
increment the counter. The read not protected by any mutex! */

ib_longlong
dict_table_autoinc_peek(
/*====================*/
				/* out: value of the counter */
	dict_table_t*	table)	/* in: table */
{
	ib_longlong	value;

	if (!table->autoinc_inited) {

		value = 0;
	} else {
		value = table->autoinc;
	}

	return(value);
}

/************************************************************************
Updates the autoinc counter if the value supplied is equal or bigger than the
current value. If not inited, does nothing. */

void
dict_table_autoinc_update(
/*======================*/

	dict_table_t*	table,	/* in: table */
	ib_longlong	value)	/* in: value which was assigned to a row */
{
	mutex_enter(&(table->autoinc_mutex));

	if (table->autoinc_inited) {
		if (value >= table->autoinc) {
			table->autoinc = value + 1;
		}
	}	

	mutex_exit(&(table->autoinc_mutex));
}

/************************************************************************
Looks for column n in an index. */

ulint
dict_index_get_nth_col_pos(
/*=======================*/
				/* out: position in internal representation
				of the index; if not contained, returns
				ULINT_UNDEFINED */
	dict_index_t*	index,	/* in: index */
	ulint		n)	/* in: column number */
{
	dict_field_t*	field;
	dict_col_t*	col;
	ulint		pos;
	ulint		n_fields;
	
	ut_ad(index);
	ut_ad(index->magic_n == DICT_INDEX_MAGIC_N);