mysql_com.h

/* Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

/*
** Common definition between mysql server & client
*/

#ifndef _mysql_com_h
#define _mysql_com_h

#define HOSTNAME_LENGTH 60
#define SYSTEM_CHARSET_MBMAXLEN 3
#define NAME_CHAR_LEN   64              /* Field/table name length */
#define USERNAME_CHAR_LENGTH 16
#define NAME_LEN                (NAME_CHAR_LEN*SYSTEM_CHARSET_MBMAXLEN)
#define USERNAME_LENGTH         (USERNAME_CHAR_LENGTH*SYSTEM_CHARSET_MBMAXLEN)

#define MYSQL_AUTODETECT_CHARSET_NAME "auto"

#define SERVER_VERSION_LENGTH 60
#define SQLSTATE_LENGTH 5

/*
  Maximum length of comments
*/
#define TABLE_COMMENT_INLINE_MAXLEN 180 /* pre 6.0: 60 characters */
#define TABLE_COMMENT_MAXLEN 2048
#define COLUMN_COMMENT_MAXLEN 1024
#define INDEX_COMMENT_MAXLEN 1024
#define TABLE_PARTITION_COMMENT_MAXLEN 1024

/*
  USER_HOST_BUFF_SIZE -- length of string buffer, that is enough to contain
  username and hostname parts of the user identifier with trailing zero in
  MySQL standard format:
  user_name_part@host_name_part\0
*/
#define USER_HOST_BUFF_SIZE HOSTNAME_LENGTH + USERNAME_LENGTH + 2

#define LOCAL_HOST      "localhost"
#define LOCAL_HOST_NAMEDPIPE "."


#if defined(__WIN__) && !defined( _CUSTOMCONFIG_)
#define MYSQL_NAMEDPIPE "MySQL"
#define MYSQL_SERVICENAME "MySQL"
#endif /* __WIN__ */

/*
  You should add new commands to the end of this list, otherwise old
  servers won't be able to handle them as 'unsupported'.
*/

enum enum_server_command
{
  COM_SLEEP, COM_QUIT, COM_INIT_DB, COM_QUERY, COM_FIELD_LIST,
  COM_CREATE_DB, COM_DROP_DB, COM_REFRESH, COM_SHUTDOWN, COM_STATISTICS,
  COM_PROCESS_INFO, COM_CONNECT, COM_PROCESS_KILL, COM_DEBUG, COM_PING,
  COM_TIME, COM_DELAYED_INSERT, COM_CHANGE_USER, COM_BINLOG_DUMP,
  COM_TABLE_DUMP, COM_CONNECT_OUT, COM_REGISTER_SLAVE,
  COM_STMT_PREPARE, COM_STMT_EXECUTE, COM_STMT_SEND_LONG_DATA, COM_STMT_CLOSE,
  COM_STMT_RESET, COM_SET_OPTION, COM_STMT_FETCH, COM_DAEMON,
  COM_BINLOG_DUMP_GTID,
  /* don't forget to update const char *command_name[] in sql_parse.cc */

  /* Must be last */
  COM_END
};


/*
  Length of random string sent by server on handshake; this is also length of
  obfuscated password, recieved from client
*/
#define SCRAMBLE_LENGTH 20
#define SCRAMBLE_LENGTH_323 8
/* length of password stored in the db: new passwords are preceeded with '*' */
#define SCRAMBLED_PASSWORD_CHAR_LENGTH (SCRAMBLE_LENGTH*2+1)
#define SCRAMBLED_PASSWORD_CHAR_LENGTH_323 (SCRAMBLE_LENGTH_323*2)


#define NOT_NULL_FLAG   1               /* Field can't be NULL */
#define PRI_KEY_FLAG    2               /* Field is part of a primary key */
#define UNIQUE_KEY_FLAG 4               /* Field is part of a unique key */
#define MULTIPLE_KEY_FLAG 8             /* Field is part of a key */
#define BLOB_FLAG       16              /* Field is a blob */
#define UNSIGNED_FLAG   32              /* Field is unsigned */
#define ZEROFILL_FLAG   64              /* Field is zerofill */
#define BINARY_FLAG     128             /* Field is binary   */

/* The following are only sent to new clients */
#define ENUM_FLAG       256             /* field is an enum */
#define AUTO_INCREMENT_FLAG 512         /* field is a autoincrement field */
#define TIMESTAMP_FLAG  1024            /* Field is a timestamp */
#define SET_FLAG        2048            /* field is a set */
#define NO_DEFAULT_VALUE_FLAG 4096      /* Field doesn't have default value */
#define ON_UPDATE_NOW_FLAG 8192         /* Field is set to NOW on UPDATE */
#define NUM_FLAG        32768           /* Field is num (for clients) */
#define PART_KEY_FLAG   16384           /* Intern; Part of some key */
#define GROUP_FLAG      32768           /* Intern: Group field */
#define UNIQUE_FLAG     65536           /* Intern: Used by sql_yacc */
#define BINCMP_FLAG     131072          /* Intern: Used by sql_yacc */
#define GET_FIXED_FIELDS_FLAG (1 << 18) /* Used to get fields in item tree */
#define FIELD_IN_PART_FUNC_FLAG (1 << 19)/* Field part of partition func */

#define FIELD_IN_ADD_INDEX (1 << 20)
#define FIELD_IS_RENAMED (1<< 21)       /* Intern: Field is being renamed */
#define FIELD_FLAGS_STORAGE_MEDIA 22    /* Field storage media, bit 22-23 */
#define FIELD_FLAGS_STORAGE_MEDIA_MASK (3 << FIELD_FLAGS_STORAGE_MEDIA)
#define FIELD_FLAGS_COLUMN_FORMAT 24    /* Field column format, bit 24-25 */
#define FIELD_FLAGS_COLUMN_FORMAT_MASK (3 << FIELD_FLAGS_COLUMN_FORMAT)
#define FIELD_IS_DROPPED (1<< 26)       /* Intern: Field is being dropped */

#define REFRESH_GRANT           1       /* Refresh grant tables */
#define REFRESH_LOG             2       /* Start on new log file */
#define REFRESH_TABLES          4       /* close all tables */
#define REFRESH_HOSTS           8       /* Flush host cache */
#define REFRESH_STATUS          16      /* Flush status variables */
#define REFRESH_THREADS         32      /* Flush thread cache */
#define REFRESH_SLAVE           64      /* Reset master info and restart slave
                                           thread */
#define REFRESH_MASTER          128     /* Remove all bin logs in the index
                                           and truncate the index */
#define REFRESH_ERROR_LOG       256 /* Rotate only the erorr log */
#define REFRESH_ENGINE_LOG      512 /* Flush all storage engine logs */
#define REFRESH_BINARY_LOG     1024 /* Flush the binary log */
#define REFRESH_RELAY_LOG      2048 /* Flush the relay log */
#define REFRESH_GENERAL_LOG    4096 /* Flush the general log */
#define REFRESH_SLOW_LOG       8192 /* Flush the slow query log */

/* The following can't be set with mysql_refresh() */
#define REFRESH_READ_LOCK       16384   /* Lock tables for read */
#define REFRESH_FAST            32768   /* Intern flag */

/* RESET (remove all queries) from query cache */
#define REFRESH_QUERY_CACHE     65536
#define REFRESH_QUERY_CACHE_FREE 0x20000L /* pack query cache */
#define REFRESH_DES_KEY_FILE    0x40000L
#define REFRESH_USER_RESOURCES  0x80000L
#define REFRESH_FOR_EXPORT      0x100000L /* FLUSH TABLES ... FOR EXPORT */

#define CLIENT_LONG_PASSWORD    1       /* new more secure passwords */
#define CLIENT_FOUND_ROWS       2       /* Found instead of affected rows */
#define CLIENT_LONG_FLAG        4       /* Get all column flags */
#define CLIENT_CONNECT_WITH_DB  8       /* One can specify db on connect */
#define CLIENT_NO_SCHEMA        16      /* Don't allow database.table.column */
#define CLIENT_COMPRESS         32      /* Can use compression protocol */
#define CLIENT_ODBC             64      /* Odbc client */
#define CLIENT_LOCAL_FILES      128     /* Can use LOAD DATA LOCAL */
#define CLIENT_IGNORE_SPACE     256     /* Ignore spaces before '(' */
#define CLIENT_PROTOCOL_41      512     /* New 4.1 protocol */
#define CLIENT_INTERACTIVE      1024    /* This is an interactive client */
#define CLIENT_SSL              2048    /* Switch to SSL after handshake */
#define CLIENT_IGNORE_SIGPIPE   4096    /* IGNORE sigpipes */
#define CLIENT_TRANSACTIONS     8192    /* Client knows about transactions */
#define CLIENT_RESERVED         16384   /* Old flag for 4.1 protocol  */
#define CLIENT_SECURE_CONNECTION 32768  /* New 4.1 authentication */
#define CLIENT_MULTI_STATEMENTS (1UL << 16) /* Enable/disable multi-stmt support */
#define CLIENT_MULTI_RESULTS    (1UL << 17) /* Enable/disable multi-results */
#define CLIENT_PS_MULTI_RESULTS (1UL << 18) /* Multi-results in PS-protocol */

#define CLIENT_PLUGIN_AUTH  (1UL << 19) /* Client supports plugin authentication */
#define CLIENT_CONNECT_ATTRS (1UL << 20) /* Client supports connection attributes */

/* Enable authentication response packet to be larger than 255 bytes. */
#define CLIENT_PLUGIN_AUTH_LENENC_CLIENT_DATA (1UL << 21)

/* Don't close the connection for a connection with expired password. */
#define CLIENT_CAN_HANDLE_EXPIRED_PASSWORDS (1UL << 22)

#define CLIENT_SSL_VERIFY_SERVER_CERT (1UL << 30)
#define CLIENT_REMEMBER_OPTIONS (1UL << 31)

#ifdef HAVE_COMPRESS
#define CAN_CLIENT_COMPRESS CLIENT_COMPRESS
#else
#define CAN_CLIENT_COMPRESS 0
#endif

/* Gather all possible capabilites (flags) supported by the server */
#define CLIENT_ALL_FLAGS  (CLIENT_LONG_PASSWORD \
                           | CLIENT_FOUND_ROWS \
                           | CLIENT_LONG_FLAG \
                           | CLIENT_CONNECT_WITH_DB \
                           | CLIENT_NO_SCHEMA \
                           | CLIENT_COMPRESS \
                           | CLIENT_ODBC \
                           | CLIENT_LOCAL_FILES \
                           | CLIENT_IGNORE_SPACE \
                           | CLIENT_PROTOCOL_41 \
                           | CLIENT_INTERACTIVE \
                           | CLIENT_SSL \
                           | CLIENT_IGNORE_SIGPIPE \
                           | CLIENT_TRANSACTIONS \
                           | CLIENT_RESERVED \
                           | CLIENT_SECURE_CONNECTION \
                           | CLIENT_MULTI_STATEMENTS \
                           | CLIENT_MULTI_RESULTS \
                           | CLIENT_PS_MULTI_RESULTS \
                           | CLIENT_SSL_VERIFY_SERVER_CERT \
                           | CLIENT_REMEMBER_OPTIONS \
                           | CLIENT_PLUGIN_AUTH \
                           | CLIENT_CONNECT_ATTRS \
                           | CLIENT_PLUGIN_AUTH_LENENC_CLIENT_DATA \
                           | CLIENT_CAN_HANDLE_EXPIRED_PASSWORDS \
)

/*
  Switch off the flags that are optional and depending on build flags
  If any of the optional flags is supported by the build it will be switched
  on before sending to the client during the connection handshake.
*/
#define CLIENT_BASIC_FLAGS (((CLIENT_ALL_FLAGS & ~CLIENT_SSL) \
                                               & ~CLIENT_COMPRESS) \
                                               & ~CLIENT_SSL_VERIFY_SERVER_CERT)

#define SERVER_STATUS_IN_TRANS     1
#define SERVER_STATUS_AUTOCOMMIT   2    /* Server in auto_commit mode */
#define SERVER_MORE_RESULTS_EXISTS 8    /* Multi query - next query exists */
#define SERVER_QUERY_NO_GOOD_INDEX_USED 16
#define SERVER_QUERY_NO_INDEX_USED      32

#define SERVER_STATUS_CURSOR_EXISTS 64

#define SERVER_STATUS_LAST_ROW_SENT 128
#define SERVER_STATUS_DB_DROPPED        256 /* A database was dropped */
#define SERVER_STATUS_NO_BACKSLASH_ESCAPES 512

#define SERVER_STATUS_METADATA_CHANGED 1024
#define SERVER_QUERY_WAS_SLOW          2048

#define SERVER_PS_OUT_PARAMS            4096

#define SERVER_STATUS_IN_TRANS_READONLY 8192


#define SERVER_STATUS_CLEAR_SET (SERVER_QUERY_NO_GOOD_INDEX_USED| \
                                 SERVER_QUERY_NO_INDEX_USED|\
                                 SERVER_MORE_RESULTS_EXISTS|\
                                 SERVER_STATUS_METADATA_CHANGED |\
                                 SERVER_QUERY_WAS_SLOW |\
                                 SERVER_STATUS_DB_DROPPED |\
                                 SERVER_STATUS_CURSOR_EXISTS|\
                                 SERVER_STATUS_LAST_ROW_SENT)

#define MYSQL_ERRMSG_SIZE       512
#define NET_READ_TIMEOUT        30              /* Timeout on read */
#define NET_WRITE_TIMEOUT       60              /* Timeout on write */
#define NET_WAIT_TIMEOUT        8*60*60         /* Wait for new query */

#define ONLY_KILL_QUERY         1


struct st_vio;                                  /* Only C */
typedef struct st_vio Vio;

#define MAX_TINYINT_WIDTH       3       /* Max width for a TINY w.o. sign */
#define MAX_SMALLINT_WIDTH      5       /* Max width for a SHORT w.o. sign */
#define MAX_MEDIUMINT_WIDTH     8       /* Max width for a INT24 w.o. sign */
#define MAX_INT_WIDTH           10      /* Max width for a LONG w.o. sign */
#define MAX_BIGINT_WIDTH        20      /* Max width for a LONGLONG */
#define MAX_CHAR_WIDTH          255     /* Max length for a CHAR colum */
#define MAX_BLOB_WIDTH          16777216        /* Default width for blob */

typedef struct st_net {
#if !defined(CHECK_EMBEDDED_DIFFERENCES) || !defined(EMBEDDED_LIBRARY)
  Vio *vio;
  unsigned char *buff,*buff_end,*write_pos,*read_pos;
  my_socket fd;                                 /* For Perl DBI/dbd */
  /*
    The following variable is set if we are doing several queries in one
    command ( as in LOAD TABLE ... FROM MASTER ),
    and do not want to confuse the client with OK at the wrong time
  */
  unsigned long remain_in_buf,length, buf_length, where_b;
  unsigned long max_packet,max_packet_size;
  unsigned int pkt_nr,compress_pkt_nr;
  unsigned int write_timeout, read_timeout, retry_count;
  int fcntl;
  unsigned int *return_status;
  unsigned char reading_or_writing;
  char save_char;
  my_bool unused1; /* Please remove with the next incompatible ABI change */
  my_bool unused2; /* Please remove with the next incompatible ABI change */
  my_bool compress;
  my_bool unused3; /* Please remove with the next incompatible ABI change. */
  /*
    Pointer to query object in query cache, do not equal NULL (0) for
    queries in cache that have not stored its results yet
  */
#endif
  /*
    Unused, please remove with the next incompatible ABI change.
  */
  unsigned char *unused;
  unsigned int last_errno;
  unsigned char error; 
  my_bool unused4; /* Please remove with the next incompatible ABI change. */
  my_bool unused5; /* Please remove with the next incompatible ABI change. */
  char last_error[MYSQL_ERRMSG_SIZE];
  char sqlstate[SQLSTATE_LENGTH+1];
  void *extension;
} NET;


#define packet_error (~(unsigned long) 0)

enum enum_field_types { MYSQL_TYPE_DECIMAL, MYSQL_TYPE_TINY,
                        MYSQL_TYPE_SHORT,  MYSQL_TYPE_LONG,
                        MYSQL_TYPE_FLOAT,  MYSQL_TYPE_DOUBLE,
                        MYSQL_TYPE_NULL,   MYSQL_TYPE_TIMESTAMP,
                        MYSQL_TYPE_LONGLONG,MYSQL_TYPE_INT24,
                        MYSQL_TYPE_DATE,   MYSQL_TYPE_TIME,
                        MYSQL_TYPE_DATETIME, MYSQL_TYPE_YEAR,
                        MYSQL_TYPE_NEWDATE, MYSQL_TYPE_VARCHAR,
                        MYSQL_TYPE_BIT,
                        MYSQL_TYPE_TIMESTAMP2,
                        MYSQL_TYPE_DATETIME2,
                        MYSQL_TYPE_TIME2,
                        MYSQL_TYPE_NEWDECIMAL=246,
                        MYSQL_TYPE_ENUM=247,
                        MYSQL_TYPE_SET=248,
                        MYSQL_TYPE_TINY_BLOB=249,
                        MYSQL_TYPE_MEDIUM_BLOB=250,
                        MYSQL_TYPE_LONG_BLOB=251,
                        MYSQL_TYPE_BLOB=252,
                        MYSQL_TYPE_VAR_STRING=253,
                        MYSQL_TYPE_STRING=254,
                        MYSQL_TYPE_GEOMETRY=255

};

/* For backward compatibility */
#define CLIENT_MULTI_QUERIES    CLIENT_MULTI_STATEMENTS    
#define FIELD_TYPE_DECIMAL     MYSQL_TYPE_DECIMAL
#define FIELD_TYPE_NEWDECIMAL  MYSQL_TYPE_NEWDECIMAL
#define FIELD_TYPE_TINY        MYSQL_TYPE_TINY
#define FIELD_TYPE_SHORT       MYSQL_TYPE_SHORT
#define FIELD_TYPE_LONG        MYSQL_TYPE_LONG
#define FIELD_TYPE_FLOAT       MYSQL_TYPE_FLOAT
#define FIELD_TYPE_DOUBLE      MYSQL_TYPE_DOUBLE
#define FIELD_TYPE_NULL        MYSQL_TYPE_NULL
#define FIELD_TYPE_TIMESTAMP   MYSQL_TYPE_TIMESTAMP
#define FIELD_TYPE_LONGLONG    MYSQL_TYPE_LONGLONG
#define FIELD_TYPE_INT24       MYSQL_TYPE_INT24
#define FIELD_TYPE_DATE        MYSQL_TYPE_DATE
#define FIELD_TYPE_TIME        MYSQL_TYPE_TIME
#define FIELD_TYPE_DATETIME    MYSQL_TYPE_DATETIME
#define FIELD_TYPE_YEAR        MYSQL_TYPE_YEAR
#define FIELD_TYPE_NEWDATE     MYSQL_TYPE_NEWDATE
#define FIELD_TYPE_ENUM        MYSQL_TYPE_ENUM
#define FIELD_TYPE_SET         MYSQL_TYPE_SET
#define FIELD_TYPE_TINY_BLOB   MYSQL_TYPE_TINY_BLOB
#define FIELD_TYPE_MEDIUM_BLOB MYSQL_TYPE_MEDIUM_BLOB
#define FIELD_TYPE_LONG_BLOB   MYSQL_TYPE_LONG_BLOB
#define FIELD_TYPE_BLOB        MYSQL_TYPE_BLOB
#define FIELD_TYPE_VAR_STRING  MYSQL_TYPE_VAR_STRING
#define FIELD_TYPE_STRING      MYSQL_TYPE_STRING
#define FIELD_TYPE_CHAR        MYSQL_TYPE_TINY
#define FIELD_TYPE_INTERVAL    MYSQL_TYPE_ENUM
#define FIELD_TYPE_GEOMETRY    MYSQL_TYPE_GEOMETRY
#define FIELD_TYPE_BIT         MYSQL_TYPE_BIT


/* Shutdown/kill enums and constants */ 

/* Bits for THD::killable. */
#define MYSQL_SHUTDOWN_KILLABLE_CONNECT    (unsigned char)(1 << 0)
#define MYSQL_SHUTDOWN_KILLABLE_TRANS      (unsigned char)(1 << 1)
#define MYSQL_SHUTDOWN_KILLABLE_LOCK_TABLE (unsigned char)(1 << 2)
#define MYSQL_SHUTDOWN_KILLABLE_UPDATE     (unsigned char)(1 << 3)

enum mysql_enum_shutdown_level {
  /*
    We want levels to be in growing order of hardness (because we use number
    comparisons). Note that DEFAULT does not respect the growing property, but
    it's ok.
  */
  SHUTDOWN_DEFAULT = 0,
  /* wait for existing connections to finish */
  SHUTDOWN_WAIT_CONNECTIONS= MYSQL_SHUTDOWN_KILLABLE_CONNECT,
  /* wait for existing trans to finish */
  SHUTDOWN_WAIT_TRANSACTIONS= MYSQL_SHUTDOWN_KILLABLE_TRANS,
  /* wait for existing updates to finish (=> no partial MyISAM update) */
  SHUTDOWN_WAIT_UPDATES= MYSQL_SHUTDOWN_KILLABLE_UPDATE,
  /* flush InnoDB buffers and other storage engines' buffers*/
  SHUTDOWN_WAIT_ALL_BUFFERS= (MYSQL_SHUTDOWN_KILLABLE_UPDATE << 1),
  /* don't flush InnoDB buffers, flush other storage engines' buffers*/
  SHUTDOWN_WAIT_CRITICAL_BUFFERS= (MYSQL_SHUTDOWN_KILLABLE_UPDATE << 1) + 1,
  /* Now the 2 levels of the KILL command */
#if MYSQL_VERSION_ID >= 50000
  KILL_QUERY= 254,
#endif
  KILL_CONNECTION= 255
};


enum enum_cursor_type
{
  CURSOR_TYPE_NO_CURSOR= 0,
  CURSOR_TYPE_READ_ONLY= 1,
  CURSOR_TYPE_FOR_UPDATE= 2,
  CURSOR_TYPE_SCROLLABLE= 4
};


/* options for mysql_set_option */
enum enum_mysql_set_option
{
  MYSQL_OPTION_MULTI_STATEMENTS_ON,
  MYSQL_OPTION_MULTI_STATEMENTS_OFF
};

#define net_new_transaction(net) ((net)->pkt_nr=0)

#ifdef __cplusplus
extern "C" {
#endif

my_bool my_net_init(NET *net, Vio* vio);
void my_net_local_init(NET *net);
void net_end(NET *net);
void net_clear(NET *net, my_bool check_buffer);
my_bool net_realloc(NET *net, size_t length);
my_bool net_flush(NET *net);
my_bool my_net_write(NET *net,const unsigned char *packet, size_t len);
my_bool net_write_command(NET *net,unsigned char command,
                          const unsigned char *header, size_t head_len,
                          const unsigned char *packet, size_t len);
my_bool net_write_packet(NET *net, const unsigned char *packet, size_t length);
unsigned long my_net_read(NET *net);

#ifdef MY_GLOBAL_INCLUDED
void my_net_set_write_timeout(NET *net, uint timeout);
void my_net_set_read_timeout(NET *net, uint timeout);
#endif

struct rand_struct {
  unsigned long seed1,seed2,max_value;
  double max_value_dbl;
};

#ifdef __cplusplus
}
#endif

  /* The following is for user defined functions */

enum Item_result {STRING_RESULT=0, REAL_RESULT, INT_RESULT, ROW_RESULT,
                  DECIMAL_RESULT};

typedef struct st_udf_args
{
  unsigned int arg_count;               /* Number of arguments */
  enum Item_result *arg_type;           /* Pointer to item_results */
  char **args;                          /* Pointer to argument */
  unsigned long *lengths;               /* Length of string arguments */
  char *maybe_null;                     /* Set to 1 for all maybe_null args */
  char **attributes;                    /* Pointer to attribute name */
  unsigned long *attribute_lengths;     /* Length of attribute arguments */
  void *extension;
} UDF_ARGS;

  /* This holds information about the result */

typedef struct st_udf_init
{
  my_bool maybe_null;          /* 1 if function can return NULL */
  unsigned int decimals;       /* for real functions */
  unsigned long max_length;    /* For string functions */
  char *ptr;                   /* free pointer for function data */
  my_bool const_item;          /* 1 if function always returns the same value */
  void *extension;
} UDF_INIT;
/* 
  TODO: add a notion for determinism of the UDF. 
  See Item_udf_func::update_used_tables ()
*/

  /* Constants when using compression */
#define NET_HEADER_SIZE 4               /* standard header size */
#define COMP_HEADER_SIZE 3              /* compression header extra size */

  /* Prototypes to password functions */

#ifdef __cplusplus
extern "C" {
#endif

/*
  These functions are used for authentication by client and server and
  implemented in sql/password.c
*/

void randominit(struct rand_struct *, unsigned long seed1,
                unsigned long seed2);
double my_rnd(struct rand_struct *);
void create_random_string(char *to, unsigned int length, struct rand_struct *rand_st);

void hash_password(unsigned long *to, const char *password, unsigned int password_len);
void make_scrambled_password_323(char *to, const char *password);
void scramble_323(char *to, const char *message, const char *password);
my_bool check_scramble_323(const unsigned char *reply, const char *message,
                           unsigned long *salt);
void get_salt_from_password_323(unsigned long *res, const char *password);
void make_password_from_salt_323(char *to, const unsigned long *salt);

void make_scrambled_password(char *to, const char *password);
void scramble(char *to, const char *message, const char *password);
my_bool check_scramble(const unsigned char *reply, const char *message,
                       const unsigned char *hash_stage2);
void get_salt_from_password(unsigned char *res, const char *password);
void make_password_from_salt(char *to, const unsigned char *hash_stage2);
char *octet2hex(char *to, const char *str, unsigned int len);

/* end of password.c */

char *get_tty_password(const char *opt_message);
const char *mysql_errno_to_sqlstate(unsigned int mysql_errno);

/* Some other useful functions */

my_bool my_thread_init(void);
void my_thread_end(void);

#ifdef MY_GLOBAL_INCLUDED
ulong STDCALL net_field_length(uchar **packet);
my_ulonglong net_field_length_ll(uchar **packet);
uchar *net_store_length(uchar *pkg, ulonglong length);
#endif

#ifdef __cplusplus
}
#endif

#define NULL_LENGTH ((unsigned long) ~0) /* For net_store_length */
#define MYSQL_STMT_HEADER       4
#define MYSQL_LONG_DATA_HEADER  6

#define NOT_FIXED_DEC           31
#endif