mysql5/mysql-5.7.27/sql/protocol.h

306 lines
9.8 KiB
C++

#ifndef PROTOCOL_INCLUDED
#define PROTOCOL_INCLUDED
/* Copyright (c) 2002, 2018, 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 */
#include "sql_error.h"
#include "my_decimal.h" /* my_decimal */
#include "violite.h" /* SSL && enum_vio_type */
#ifdef __cplusplus
class THD;
#define MYSQL_THD THD*
#else
#define MYSQL_THD void*
#endif
#include "mysql/com_data.h"
class Send_field;
class Proto_field;
class Protocol {
public:
/**
Read packet from client
@returns
-1 fatal error
0 ok
1 non-fatal error
*/
virtual int read_packet()= 0;
/**
Reads the command from the protocol and creates a command.
@param com_data out parameter
@param cmd out parameter
@param pkt packet to be parsed
@param length size of the packet
@returns
-1 fatal protcol error
0 ok
1 non-fatal protocol or parsing error
*/
virtual int get_command(COM_DATA *com_data, enum_server_command *cmd)= 0;
/**
Enum used by type() to specify the protocol type
*/
enum enum_protocol_type
{
/*
Before adding a new type, please make sure
there is enough storage for it in Query_cache_query_flags.
*/
PROTOCOL_TEXT= 0, // text Protocol type used mostly
// for the old (MySQL 4.0 protocol)
PROTOCOL_BINARY= 1, // binary protocol type
PROTOCOL_LOCAL= 2, // local protocol type(intercepts communication)
PROTOCOL_ERROR = 3, // error protocol instance
PROTOCOL_PLUGIN = 4 // pluggable protocol type
};
/**
Flags available to alter the way the messages are sent to the client
*/
enum
{
SEND_NUM_ROWS= 1,
SEND_DEFAULTS= 2,
SEND_EOF= 4
};
virtual enum enum_protocol_type type()= 0;
virtual enum enum_vio_type connection_type()= 0;
/* Data sending functions */
virtual bool store_null()= 0;
virtual bool store_tiny(longlong from)= 0;
virtual bool store_short(longlong from)= 0;
virtual bool store_long(longlong from)= 0;
virtual bool store_longlong(longlong from, bool unsigned_flag)= 0;
virtual bool store_decimal(const my_decimal *, uint, uint)= 0;
virtual bool store(const char *from, size_t length,
const CHARSET_INFO *fromcs)= 0;
virtual bool store(float from, uint32 decimals, String *buffer)= 0;
virtual bool store(double from, uint32 decimals, String *buffer)= 0;
virtual bool store(MYSQL_TIME *time, uint precision)= 0;
virtual bool store_date(MYSQL_TIME *time)= 0;
virtual bool store_time(MYSQL_TIME *time, uint precision)= 0;
virtual bool store(Proto_field *field)= 0;
// Convenience wrappers
inline bool store(int from)
{ return store_long((longlong) from); }
inline bool store(uint32 from)
{ return store_long((longlong) from); }
inline bool store(longlong from)
{ return store_longlong(from, 0); }
inline bool store(ulonglong from)
{ return store_longlong((longlong) from, 1); }
/**
Send \\0 end terminated string.
@param from NullS or \\0 terminated string
@note In most cases one should use store(from, length, cs) instead of
this function
@returns
false ok
true error
*/
inline bool store(const char *from, const CHARSET_INFO *fromcs)
{ return from ? store(from, strlen(from), fromcs) : store_null(); }
inline bool store(String *str)
{ return store((char*) str->ptr(), str->length(), str->charset()); }
inline bool store(const LEX_STRING &s, const CHARSET_INFO *cs)
{ return store(s.str, s.length, cs); }
/**
Returns the client capabilities stored on the protocol.
The available capabilites are defined in mysql_com.h
*/
virtual ulong get_client_capabilities()= 0;
/**
Checks if the client capabilities include the one
specified as parameter.
@returns
true if it includes the specified capability
false otherwise
*/
virtual bool has_client_capability(unsigned long client_capability)= 0;
/**
Checks if the protocol's connection with the client is still alive.
It should always return true unless the protocol closed the connection.
@returns
true if the connection is still alive
false otherwise
*/
virtual bool connection_alive()= 0;
/**
Result set sending functions
@details Server uses following schema to send result:
... sending metadata ...
| start_result_metadata(...)
| start_row()
| send_field_metadata(...)
| end_row()
... same for each field sent ...
| end_result_metadata(...)
|
... sending result ...
| start_row(...)
| store_xxx(...)
... store_xxx(..) is called for each field ...
| end_row(...)
... same for each row, until all rows are sent ...
| send_ok/eof/error(...)
However, a protocol implementation might use different schema. For
example, Protocol_callback ignores start/end_row when metadata is being
sent.
*/
virtual void start_row()= 0;
virtual bool end_row()= 0;
virtual void abort_row()= 0;
virtual void end_partial_result_set()= 0;
/**
Thread is being shut down, disconnect and free resources
@param server_shutdown If false then this is normal thread shutdown. If
true then the server is shutting down.
*/
virtual int shutdown(bool server_shutdown= false)= 0;
/**
Returns the read/writing status
@return
@retval 1 Read
@retval 2 Write
@retval 0 Other(Idle, Killed)
*/
virtual uint get_rw_status()= 0;
/**
Returns if the protocol is compressed or not.
@return
@retval false Not compressed
@retval true Compressed
*/
virtual bool get_compression()= 0;
/**
Prepares the server for metadata sending.
Notifies the client that the metadata sending will start.
@param num_cols Number of columns that will be sent
@param flags Flags to alter the metadata sending
Can be any of the following:
SEND_NUM_ROWS, SEND_DEFAULTS, SEND_EOF
@param resultcs Charset to convert to
@return
@retval false Ok
@retval true An error occurred
*/
virtual bool start_result_metadata(uint num_cols, uint flags,
const CHARSET_INFO *resultcs)= 0;
/**
Sends field metadata.
@param field Field metadata to be send to the client
@param field Field to be send to the client
@param charset Field's charset: in case it is different
than the one used by the connection it will
be used to convert the value to
the connection's charset
@return
@retval false The metadata was successfully sent
@retval true An error occurred
*/
virtual bool send_field_metadata(Send_field *field,
const CHARSET_INFO *charset)= 0;
/**
Signals the client that the metadata sending is done.
Clears the server after sending the metadata.
@return
@retval false Ok
@retval true An error occurred
*/
virtual bool end_result_metadata()= 0;
/**
Send ok message to the client.
@param server_status The server status
@param statement_warn_count Total number of warnings
@param affected_rows Number of rows changed by statement
@param last_insert_id Last insert id (Auto_increment id for first
row if used)
@param message Message to send to the client
@return
@retval false The message was successfully sent
@retval true An error occurred and the messages wasn't sent properly
*/
virtual bool send_ok(uint server_status, uint statement_warn_count,
ulonglong affected_rows, ulonglong last_insert_id,
const char *message)= 0;
/**
Send eof message to the client.
@param server_status The server status
@param statement_warn_count Total number of warnings
@return
@retval false The message was successfully sent
@retval true An error occurred and the messages wasn't sent properly
*/
virtual bool send_eof(uint server_status, uint statement_warn_count)= 0;
/**
Send error message to the client.
@param sql_errno The error code to send
@param err A pointer to the error message
@param sqlstate SQL state
@return
@retval false The message was successfully sent
@retval true An error occurred and the messages wasn't sent properly
*/
virtual bool send_error(uint sql_errno, const char *err_msg,
const char *sql_state)= 0;
};
#endif /* PROTOCOL_INCLUDED */