ndbdictionary.hpp

在AS4下编译通过

/* Copyright (C) 2003 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 */

#ifndef NdbDictionary_H
#define NdbDictionary_H

#include <ndb_types.h>

class Ndb;
struct charset_info_st;
typedef struct charset_info_st CHARSET_INFO;

/**
 * @class NdbDictionary
 * @brief Data dictionary class
 * 
 * The preferred and supported way to create and drop tables and indexes
 * in ndb is through the 
 * MySQL Server (see MySQL reference Manual, section MySQL Cluster).
 *
 * Tables and indexes that are created directly through the 
 * NdbDictionary class
 * can not be viewed from the MySQL Server.
 * Dropping indexes directly via the NdbApi will cause inconsistencies
 * if they were originally created from a MySQL Cluster.
 * 
 * This class supports schema data enquiries such as:
 * -# Enquiries about tables
 *    (Dictionary::getTable, Table::getNoOfColumns, 
 *    Table::getPrimaryKey, and Table::getNoOfPrimaryKeys)
 * -# Enquiries about indexes
 *    (Dictionary::getIndex, Index::getNoOfColumns, 
 *    and Index::getColumn)
 *
 * This class supports schema data definition such as:
 * -# Creating tables (Dictionary::createTable) and table columns
 * -# Dropping tables (Dictionary::dropTable)
 * -# Creating secondary indexes (Dictionary::createIndex)
 * -# Dropping secondary indexes (Dictionary::dropIndex)
 *
 * NdbDictionary has several help (inner) classes to support this:
 * -# NdbDictionary::Dictionary the dictionary handling dictionary objects
 * -# NdbDictionary::Table for creating tables
 * -# NdbDictionary::Column for creating table columns
 * -# NdbDictionary::Index for creating secondary indexes
 *
 * See @ref ndbapi_simple_index.cpp for details of usage.
 */
class NdbDictionary {
public:
  NdbDictionary() {}                          /* Remove gcc warning */
  /**
   * @class Object
   * @brief Meta information about a database object (a table, index, etc)
   */
  class Object {
  public:
    Object() {}                               /* Remove gcc warning */
    virtual ~Object() {}                      /* Remove gcc warning */
    /**
     * Status of object
     */
    enum Status {
      New,                    ///< The object only exist in memory and 
                              ///< has not been created in the NDB Kernel
      Changed,                ///< The object has been modified in memory 
                              ///< and has to be commited in NDB Kernel for 
                              ///< changes to take effect
      Retrieved,              ///< The object exist and has been read 
                              ///< into main memory from NDB Kernel
      Invalid,                ///< The object has been invalidated
                              ///< and should not be used
      Altered                 ///< Table has been altered in NDB kernel
                              ///< but is still valid for usage
    };

    /**
     * Get status of object
     */
    virtual Status getObjectStatus() const = 0;

    /**
     * Get version of object
     */
    virtual int getObjectVersion() const = 0;

    /**
     * Object type
     */
    enum Type {
      TypeUndefined = 0,      ///< Undefined
      SystemTable = 1,        ///< System table
      UserTable = 2,          ///< User table (may be temporary)
      UniqueHashIndex = 3,    ///< Unique un-ordered hash index
      OrderedIndex = 6,       ///< Non-unique ordered index
      HashIndexTrigger = 7,   ///< Index maintenance, internal
      IndexTrigger = 8,       ///< Index maintenance, internal
      SubscriptionTrigger = 9,///< Backup or replication, internal
      ReadOnlyConstraint = 10 ///< Trigger, internal
    };

    /**
     * Object state
     */
    enum State {
      StateUndefined = 0,     ///< Undefined
      StateOffline = 1,       ///< Offline, not usable
      StateBuilding = 2,      ///< Building, not yet usable
      StateDropping = 3,      ///< Offlining or dropping, not usable
      StateOnline = 4,        ///< Online, usable
      StateBackup = 5,        ///< Online, being backuped, usable
      StateBroken = 9         ///< Broken, should be dropped and re-created
    };

    /**
     * Object store
     */
    enum Store {
      StoreUndefined = 0,     ///< Undefined
      StoreTemporary = 1,     ///< Object or data deleted on system restart
      StorePermanent = 2      ///< Permanent. logged to disk
    };

    /**
     * Type of fragmentation.
     *
     * This parameter specifies how data in the table or index will
     * be distributed among the db nodes in the cluster.<br>
     * The bigger the table the more number of fragments should be used.
     * Note that all replicas count as same "fragment".<br>
     * For a table, default is FragAllMedium.  For a unique hash index,
     * default is taken from underlying table and cannot currently
     * be changed.
     */
    enum FragmentType { 
      FragUndefined = 0,      ///< Fragmentation type undefined or default
      FragSingle = 1,         ///< Only one fragment
      FragAllSmall = 2,       ///< One fragment per node, default
      FragAllMedium = 3,      ///< two fragments per node
      FragAllLarge = 4        ///< Four fragments per node.
    };
  };

  class Table; // forward declaration
  
  /**
   * @class Column
   * @brief Represents a column in an NDB Cluster table
   *
   * Each column has a type. The type of a column is determined by a number 
   * of type specifiers.
   * The type specifiers are:
   * - Builtin type
   * - Array length or max length
   * - Precision and scale (not used yet)
   * - Character set for string types
   * - Inline and part sizes for blobs
   *
   * Types in general correspond to MySQL types and their variants.
   * Data formats are same as in MySQL.  NDB API provides no support for
   * constructing such formats.  NDB kernel checks them however.
   */
  class Column {
  public:
    /**
     * The builtin column types
     */
    enum Type {
      Undefined = NDB_TYPE_UNDEFINED,   ///< Undefined 
      Tinyint = NDB_TYPE_TINYINT,       ///< 8 bit. 1 byte signed integer, can be used in array
      Tinyunsigned = NDB_TYPE_TINYUNSIGNED,  ///< 8 bit. 1 byte unsigned integer, can be used in array
      Smallint = NDB_TYPE_SMALLINT,      ///< 16 bit. 2 byte signed integer, can be used in array
      Smallunsigned = NDB_TYPE_SMALLUNSIGNED, ///< 16 bit. 2 byte unsigned integer, can be used in array
      Mediumint = NDB_TYPE_MEDIUMINT,     ///< 24 bit. 3 byte signed integer, can be used in array
      Mediumunsigned = NDB_TYPE_MEDIUMUNSIGNED,///< 24 bit. 3 byte unsigned integer, can be used in array
      Int = NDB_TYPE_INT,           ///< 32 bit. 4 byte signed integer, can be used in array
      Unsigned = NDB_TYPE_UNSIGNED,      ///< 32 bit. 4 byte unsigned integer, can be used in array
      Bigint = NDB_TYPE_BIGINT,        ///< 64 bit. 8 byte signed integer, can be used in array
      Bigunsigned = NDB_TYPE_BIGUNSIGNED,   ///< 64 Bit. 8 byte signed integer, can be used in array
      Float = NDB_TYPE_FLOAT,         ///< 32-bit float. 4 bytes float, can be used in array
      Double = NDB_TYPE_DOUBLE,        ///< 64-bit float. 8 byte float, can be used in array
      Olddecimal = NDB_TYPE_OLDDECIMAL,    ///< MySQL < 5.0 signed decimal,  Precision, Scale
      Olddecimalunsigned = NDB_TYPE_OLDDECIMALUNSIGNED,
      Decimal = NDB_TYPE_DECIMAL,    ///< MySQL >= 5.0 signed decimal,  Precision, Scale
      Decimalunsigned = NDB_TYPE_DECIMALUNSIGNED,
      Char = NDB_TYPE_CHAR,          ///< Len. A fixed array of 1-byte chars
      Varchar = NDB_TYPE_VARCHAR,       ///< Length bytes: 1, Max: 255
      Binary = NDB_TYPE_BINARY,        ///< Len
      Varbinary = NDB_TYPE_VARBINARY,     ///< Length bytes: 1, Max: 255
      Datetime = NDB_TYPE_DATETIME,    ///< Precision down to 1 sec (sizeof(Datetime) == 8 bytes )
      Date = NDB_TYPE_DATE,            ///< Precision down to 1 day(sizeof(Date) == 4 bytes )
      Blob = NDB_TYPE_BLOB,        ///< Binary large object (see NdbBlob)
      Text = NDB_TYPE_TEXT,         ///< Text blob
      Bit = NDB_TYPE_BIT,          ///< Bit, length specifies no of bits
      Longvarchar = NDB_TYPE_LONGVARCHAR,  ///< Length bytes: 2, little-endian
      Longvarbinary = NDB_TYPE_LONGVARBINARY, ///< Length bytes: 2, little-endian
      Time = NDB_TYPE_TIME,        ///< Time without date
      Year = NDB_TYPE_YEAR,   ///< Year 1901-2155 (1 byte)
      Timestamp = NDB_TYPE_TIMESTAMP  ///< Unix time
    };

    /** 
     * @name General 
     * @{
     */
    
    /**
     * Get name of column
     * @return  Name of the column
     */
    const char* getName() const;

    /**
     * Get if the column is nullable or not
     */
    bool getNullable() const;
    
    /**
     * Check if column is part of primary key
     */
    bool getPrimaryKey() const;

    /**
     *  Get number of column (horizontal position within table)
     */
    int getColumnNo() const;

    /**
     * Check if column is equal to some other column
     * @param  column  Column to compare with
     * @return  true if column is equal to some other column otherwise false.
     */
    bool equal(const Column& column) const;


    /** @} *******************************************************************/
    /** 
     * @name Get Type Specifiers
     * @{
     */

    /**
     * Get type of column
     */
    Type getType() const;

    /**
     * Get precision of column.
     * @note Only applicable for decimal types
     */
    int getPrecision() const;

    /**
     * Get scale of column.
     * @note Only applicable for decimal types
     */
    int getScale() const;

    /**
     * Get length for column
     * Array length for column or max length for variable length arrays.
     */
    int getLength() const;

    /**
     * For Char or Varchar or Text, get MySQL CHARSET_INFO.  This
     * specifies both character set and collation.  See get_charset()
     * etc in MySQL.  (The cs is not "const" in MySQL).
     */
    CHARSET_INFO* getCharset() const;


    /**
     * For blob, get "inline size" i.e. number of initial bytes
     * to store in table's blob attribute.  This part is normally in
     * main memory and can be indexed and interpreted.
     */
    int getInlineSize() const;

    /**
     * For blob, get "part size" i.e. number of bytes to store in
     * each tuple of the "blob table".  Can be set to zero to omit parts
     * and to allow only inline bytes ("tinyblob").
     */
    int getPartSize() const;

    /**
     * For blob, set or get "stripe size" i.e. number of consecutive
     * <em>parts</em> to store in each node group.
     */
    int getStripeSize() const;

    /**
     * Get size of element
     */
    int getSize() const;

    /** 
     * Check if column is part of partition key
     *
     * A <em>partition key</em> is a set of attributes which are used
     * to distribute the tuples onto the NDB nodes.
     * The partition key uses the NDB Cluster hashing function.
     *
     * An example where this is useful is TPC-C where it might be
     * good to use the warehouse id and district id as the partition key. 
     * This would place all data for a specific district and warehouse 
     * in the same database node.
     *
     * Locally in the fragments the full primary key 
     * will still be used with the hashing algorithm.
     *
     * @return  true then the column is part of 
     *                 the partition key.
     */
    bool getPartitionKey() const;
#ifndef DOXYGEN_SHOULD_SKIP_DEPRECATED
    inline bool getDistributionKey() const { return getPartitionKey(); };
#endif

    /** @} *******************************************************************/


    /** 
     * @name Column creation
     * @{
     *
     * These operations should normally not be performed in an NbdApi program
     * as results will not be visable in the MySQL Server
     * 
     */

    /**
     * Constructor
     * @param   name   Name of column
     */
    Column(const char * name = "");
    /**
     * Copy constructor
     * @param  column  Column to be copied
     */
    Column(const Column& column); 
    ~Column();

    /**
     * Set name of column
     * @param  name  Name of the column
     */
    int setName(const char * name);

    /**
     * Set whether column is nullable or not
     */
    void setNullable(bool);

    /**
     * Set that column is part of primary key
     */
    void setPrimaryKey(bool);

    /**
     * Set type of column
     * @param  type  Type of column
     *
     * @note setType resets <em>all</em> column attributes
     *       to (type dependent) defaults and should be the first
     *       method to call.  Default type is Unsigned.
     */
    void setType(Type type);

    /**
     * Set precision of column.
     * @note Only applicable for decimal types
     */
    void setPrecision(int);

    /**
     * Set scale of column.
     * @note Only applicable for decimal types
     */
    void setScale(int);

    /**
     * Set length for column
     * Array length for column or max length for variable length arrays.
     */
    void setLength(int length);

    /**
     * For Char or Varchar or Text, get MySQL CHARSET_INFO.  This