MySQL 8.0.32
Source Code Documentation
mysql_async.h
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1/* Copyright (c) 2019, 2022, Oracle and/or its affiliates.
2
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15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License, version 2.0, for more details.
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20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
22
23#ifndef MYSQL_ASYNC_INCLUDED
24#define MYSQL_ASYNC_INCLUDED
25
26#include <mysql.h>
27
28/**
29 @file mysql_async.h
30
31 Declarations for asynchronous client communication.
32
33 @note this file should not be included as part of packaging.
34*/
35
36/**
37 This enum is to represent different asynchronous operations like reading the
38 network, writing to network, idle state, or complete state.
39*/
41 NET_ASYNC_OP_IDLE = 0, /**< default state */
42 NET_ASYNC_OP_READING, /**< used by my_net_read calls */
43 NET_ASYNC_OP_WRITING, /**< used by my_net_write calls */
44 NET_ASYNC_OP_COMPLETE /**< network read or write is complete */
45};
46
47/** Reading a packet is a multi-step process, so we have a state machine. */
49 NET_ASYNC_PACKET_READ_IDLE = 0, /**< default packet read state */
50 NET_ASYNC_PACKET_READ_HEADER, /**< read packet header */
51 NET_ASYNC_PACKET_READ_BODY, /**< read packet contents */
52 NET_ASYNC_PACKET_READ_COMPLETE /**< state to define if packet is
53 completely read */
54};
55
56/** Different states when reading a query result. */
58 NET_ASYNC_READ_QUERY_RESULT_IDLE = 0, /**< default state */
59 NET_ASYNC_READ_QUERY_RESULT_FIELD_COUNT, /**< read Ok or read field
60 count sent as part of
61 COM_QUERY */
62 NET_ASYNC_READ_QUERY_RESULT_FIELD_INFO /**< read result of above
63 COM_* command */
64};
65
66/** Sending a command involves the write as well as reading the status. */
68 NET_ASYNC_SEND_COMMAND_IDLE = 0, /**< default send command state */
69 NET_ASYNC_SEND_COMMAND_WRITE_COMMAND, /**< send COM_* command */
70 NET_ASYNC_SEND_COMMAND_READ_STATUS /**< read result of above COM_*
71 command */
72};
73
74/**
75 Async operations are broadly classified into 3 phases:
76 Connection phase, phase of sending data to server (which is writing phase)
77 and reading data from server (which is reading phase). Below enum describes
78 the same
79*/
84};
85
86/**
87 Represents the packet to be sent on wire asynchronously.
88*/
89struct io_vec {
90 void *iov_base; /**< Starting address */
91 size_t iov_len; /**< Number of bytes to transfer */
92};
93
94typedef struct NET_ASYNC {
95 /**
96 The position in buff we continue reads from when data is next
97 available
98 */
99 unsigned char *cur_pos;
100 /** Blocking state */
102 /** Our current operation */
104 /** How many bytes we want to read */
106 /**
107 Simple state to know if we're reading the first row, and
108 command/query statuses.
109 */
113
114 /** State when waiting on an async read */
116 /** Size of the packet we're currently reading */
118
119 /**
120 Headers and vector for our async writes; see net_serv.c for
121 detailed description.
122 */
123 unsigned char *async_write_headers;
127
128 /**
129 If the packet length is less than MAX_PACKET_LENGTH then use a static array
130 to hold the meta packet header. The array either holds the usual packet
131 header or a compressed meta packet header as following. The compressed
132 meta packet header is followwed by usual compresses packet heder that is
133 7 bytes in length.
134
135
136 Packet
137
138 Header
139 ~~~~~~~~~~~~~~~~~~~
140 B1 B2 B3 : Packet length
141 B4 : Packet number
142 ~~~~~~~~~~~~~~~~~~~
143
144 Payload
145 ~~~~~~~~~~~~~~~~~~~
146 B5 : COM_COMMAND
147 ~~~~~~~~~~~~~~~~~~~
148
149 Compressed Packet
150
151 Header
152 ~~~~~~~~~~~~~~~~~~~
153 B1 B2 B3 : Compress packet length
154 B4 : Compress Packet Nunmber
155 00 00 00 : Indicates following payload is uncompressed
156 ~~~~~~~~~~~~~~~~~~~
157
158 Payload
159 ~~~~~~~~~~~~~~~~~~~
160 B8 B9 B10 : Packet size
161 B11 : Packet number
162 B12 : COM_COMMAND
163 ~~~~~~~~~~~~~~~~~~~
164 */
166 NET_HEADER_SIZE + 1];
168
169 /** Keep track of compressed buffers */
171 /** Size of the compressed buffer */
174
178};
179
181void net_extension_free(NET *);
182
183#define NET_EXTENSION_PTR(N) \
184 ((NET_EXTENSION *)((N)->extension ? (N)->extension : NULL))
185
186#define NET_ASYNC_DATA(M) \
187 ((NET_EXTENSION_PTR(M)) ? (NET_EXTENSION_PTR(M)->net_async_context) : NULL)
188
189/**
190 Asynchronous operations are broadly classified into 2 categories.
191 1. Connection
192 2. Query execution
193 This classification is defined in below enum
194*/
200
201/**
202 Query execution in an asynchronous fashion is broadly divided into 3 states
203 which is described in below enum
204*/
210
211typedef struct MYSQL_ASYNC {
212 /** Buffer storing the rows result for cli_read_rows_nonblocking */
214 /** a pointer to keep track of the previous row of the current result row */
216 /** Context needed to track the state of a connection being established */
218 /** Status of the current async op */
220 /** Size of the current running async query */
222 /** If a query is running, this is its state */
224 /** context needed to support metadata read operation */
229 /** a pointer to keep track of the result sets */
231
232 /** the query parameters data */
234 /** the query parameters data length */
235 unsigned long async_qp_data_length;
236
238
240 const unsigned char *packet,
241 size_t len, bool *res);
243 NET *net, unsigned char command, const unsigned char *prefix,
244 size_t prefix_len, const unsigned char *packet, size_t packet_len,
245 bool *res);
246enum net_async_status my_net_read_nonblocking(NET *net, unsigned long *len_ptr);
247
249
250#endif /* MYSQL_ASYNC_INCLUDED */
#define COMP_HEADER_SIZE
compression header extra size
Definition: mysql_com.h:1121
#define NET_HEADER_SIZE
standard header size
Definition: mysql_com.h:1120
unsigned char uchar
Definition: my_inttypes.h:51
static MYSQL mysql
Definition: mysql.cc:153
This file defines the client API to MySQL and also the ABI of the dynamically linked libmysqlclient.
NET_EXTENSION * net_extension_init()
Definition: net_serv.cc:99
struct MYSQL_ASYNC MYSQL_ASYNC
int mysql_get_socket_descriptor(MYSQL *mysql)
Definition: client.cc:4766
net_read_query_result_status
Different states when reading a query result.
Definition: mysql_async.h:57
@ NET_ASYNC_READ_QUERY_RESULT_FIELD_COUNT
read Ok or read field count sent as part of COM_QUERY
Definition: mysql_async.h:59
@ NET_ASYNC_READ_QUERY_RESULT_IDLE
default state
Definition: mysql_async.h:58
@ NET_ASYNC_READ_QUERY_RESULT_FIELD_INFO
read result of above COM_* command
Definition: mysql_async.h:62
void net_extension_free(NET *)
Definition: net_serv.cc:108
enum net_async_status net_write_command_nonblocking(NET *net, unsigned char command, const unsigned char *prefix, size_t prefix_len, const unsigned char *packet, size_t packet_len, bool *res)
Send a command to the server in asynchronous way.
Definition: net_serv.cc:786
net_async_read_packet_state
Reading a packet is a multi-step process, so we have a state machine.
Definition: mysql_async.h:48
@ NET_ASYNC_PACKET_READ_COMPLETE
state to define if packet is completely read
Definition: mysql_async.h:52
@ NET_ASYNC_PACKET_READ_BODY
read packet contents
Definition: mysql_async.h:51
@ NET_ASYNC_PACKET_READ_IDLE
default packet read state
Definition: mysql_async.h:49
@ NET_ASYNC_PACKET_READ_HEADER
read packet header
Definition: mysql_async.h:50
enum net_async_status my_net_read_nonblocking(NET *net, unsigned long *len_ptr)
net_async_block_state
Async operations are broadly classified into 3 phases: Connection phase, phase of sending data to ser...
Definition: mysql_async.h:80
@ NET_NONBLOCKING_READ
Definition: mysql_async.h:82
@ NET_NONBLOCKING_WRITE
Definition: mysql_async.h:83
@ NET_NONBLOCKING_CONNECT
Definition: mysql_async.h:81
net_send_command_status
Sending a command involves the write as well as reading the status.
Definition: mysql_async.h:67
@ NET_ASYNC_SEND_COMMAND_IDLE
default send command state
Definition: mysql_async.h:68
@ NET_ASYNC_SEND_COMMAND_READ_STATUS
read result of above COM_* command
Definition: mysql_async.h:70
@ NET_ASYNC_SEND_COMMAND_WRITE_COMMAND
send COM_* command
Definition: mysql_async.h:69
struct NET_ASYNC NET_ASYNC
mysql_async_query_state_enum
Query execution in an asynchronous fashion is broadly divided into 3 states which is described in bel...
Definition: mysql_async.h:205
@ QUERY_READING_RESULT
Definition: mysql_async.h:208
@ QUERY_IDLE
Definition: mysql_async.h:206
@ QUERY_SENDING
Definition: mysql_async.h:207
mysql_async_operation_status
Asynchronous operations are broadly classified into 2 categories.
Definition: mysql_async.h:195
@ ASYNC_OP_CONNECT
Definition: mysql_async.h:197
@ ASYNC_OP_UNSET
Definition: mysql_async.h:196
@ ASYNC_OP_QUERY
Definition: mysql_async.h:198
enum net_async_status my_net_write_nonblocking(NET *net, const unsigned char *packet, size_t len, bool *res)
Definition: net_serv.cc:838
net_async_operation
This enum is to represent different asynchronous operations like reading the network,...
Definition: mysql_async.h:40
@ NET_ASYNC_OP_IDLE
default state
Definition: mysql_async.h:41
@ NET_ASYNC_OP_READING
used by my_net_read calls
Definition: mysql_async.h:42
@ NET_ASYNC_OP_WRITING
used by my_net_write calls
Definition: mysql_async.h:43
@ NET_ASYNC_OP_COMPLETE
network read or write is complete
Definition: mysql_async.h:44
Definition: buffer.h:43
net_async_status
Definition: plugin_auth_common.h:135
Definition: mysql_async.h:211
MYSQL_ROWS ** prev_row_ptr
a pointer to keep track of the previous row of the current result row
Definition: mysql_async.h:215
enum mysql_async_query_state_enum async_query_state
If a query is running, this is its state.
Definition: mysql_async.h:223
unsigned int async_read_metadata_cur_field
Definition: mysql_async.h:228
MYSQL_FIELD * async_read_metadata_fields
Definition: mysql_async.h:226
struct mysql_async_connect * connect_context
Context needed to track the state of a connection being established.
Definition: mysql_async.h:217
MYSQL_ROWS async_read_metadata_data
Definition: mysql_async.h:227
struct MYSQL_RES * async_store_result_result
a pointer to keep track of the result sets
Definition: mysql_async.h:230
unsigned long async_qp_data_length
the query parameters data length
Definition: mysql_async.h:235
size_t async_query_length
Size of the current running async query.
Definition: mysql_async.h:221
MYSQL_DATA * rows_result_buffer
Buffer storing the rows result for cli_read_rows_nonblocking.
Definition: mysql_async.h:213
unsigned long * async_read_metadata_field_len
context needed to support metadata read operation
Definition: mysql_async.h:225
uchar * async_qp_data
the query parameters data
Definition: mysql_async.h:233
enum mysql_async_operation_status async_op_status
Status of the current async op.
Definition: mysql_async.h:219
Definition: mysql.h:162
Definition: mysql.h:120
Definition: mysql.h:338
Definition: mysql.h:152
Definition: mysql.h:298
Definition: mysql_async.h:94
struct io_vec * async_write_vector
Definition: mysql_async.h:124
enum net_async_operation async_operation
Our current operation.
Definition: mysql_async.h:103
size_t async_write_vector_size
Definition: mysql_async.h:125
unsigned char inline_async_write_header[NET_HEADER_SIZE+COMP_HEADER_SIZE+NET_HEADER_SIZE+1]
If the packet length is less than MAX_PACKET_LENGTH then use a static array to hold the meta packet h...
Definition: mysql_async.h:166
enum net_async_block_state async_blocking_state
Blocking state.
Definition: mysql_async.h:101
struct io_vec inline_async_write_vector[3]
Definition: mysql_async.h:167
bool read_rows_is_first_read
Simple state to know if we're reading the first row, and command/query statuses.
Definition: mysql_async.h:110
enum net_send_command_status async_send_command_status
Definition: mysql_async.h:111
size_t async_packet_length
Size of the packet we're currently reading.
Definition: mysql_async.h:117
size_t async_bytes_wanted
How many bytes we want to read.
Definition: mysql_async.h:105
unsigned char * cur_pos
The position in buff we continue reads from when data is next available.
Definition: mysql_async.h:99
unsigned char * async_write_headers
Headers and vector for our async writes; see net_serv.c for detailed description.
Definition: mysql_async.h:123
unsigned char ** compressed_write_buffers
Keep track of compressed buffers.
Definition: mysql_async.h:170
size_t compressed_buffers_size
Size of the compressed buffer.
Definition: mysql_async.h:172
enum net_async_read_packet_state async_packet_read_state
State when waiting on an async read.
Definition: mysql_async.h:115
size_t async_write_vector_current
Definition: mysql_async.h:126
enum net_read_query_result_status async_read_query_result_status
Definition: mysql_async.h:112
Definition: mysql_async.h:175
mysql_compress_context compress_ctx
Definition: mysql_async.h:177
NET_ASYNC * net_async_context
Definition: mysql_async.h:176
Definition: mysql_com.h:912
Represents the packet to be sent on wire asynchronously.
Definition: mysql_async.h:89
size_t iov_len
Number of bytes to transfer.
Definition: mysql_async.h:91
void * iov_base
Starting address.
Definition: mysql_async.h:90
Definition: client_async_authentication.h:161
Compression context information.
Definition: my_compress.h:73
command
Definition: version_token.cc:279