49ab5797a2
Basically it would be trivial to report far more operations explicitly, but for the fact that the values in qc_query_op_t currently, quite unnecessarily, form a bitmask. In 2.2 that is no longer the case, so other operations will be added there.
763 lines
27 KiB
C
763 lines
27 KiB
C
#pragma once
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/*
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* Copyright (c) 2016 MariaDB Corporation Ab
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*
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* Use of this software is governed by the Business Source License included
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* in the LICENSE.TXT file and at www.mariadb.com/bsl11.
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*
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* Change Date: 2019-07-01
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*
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* On the date above, in accordance with the Business Source License, use
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* of this software will be governed by version 2 or later of the General
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* Public License.
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*/
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#include <maxscale/cdefs.h>
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#include <maxscale/buffer.h>
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MXS_BEGIN_DECLS
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#define QUERY_CLASSIFIER_VERSION {1, 1, 0}
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/**
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* qc_init_kind_t specifies what kind of initialization should be performed.
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*/
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typedef enum qc_init_kind
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{
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QC_INIT_SELF = 0x01, /*< Initialize/finalize the query classifier itself. */
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QC_INIT_PLUGIN = 0x02, /*< Initialize/finalize the plugin. */
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QC_INIT_BOTH = 0x03
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} qc_init_kind_t;
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/**
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* @c qc_collect_info_t specifies what information should be collected during parsing.
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*/
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typedef enum qc_collect_info
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{
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QC_COLLECT_ESSENTIALS = 0x00, /*< Collect only the base minimum. */
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QC_COLLECT_TABLES = 0x01, /*< Collect table names. */
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QC_COLLECT_DATABASES = 0x02, /*< Collect database names. */
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QC_COLLECT_FIELDS = 0x04, /*< Collect field information. */
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QC_COLLECT_FUNCTIONS = 0x08, /*< Collect function information. */
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QC_COLLECT_ALL = (QC_COLLECT_TABLES|QC_COLLECT_DATABASES|QC_COLLECT_FIELDS|QC_COLLECT_FUNCTIONS)
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} qc_collect_info_t;
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/**
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* qc_query_type_t defines bits that provide information about a
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* particular statement.
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*
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* Note that more than one bit may be set for a single statement.
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*/
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typedef enum qc_query_type
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{
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QUERY_TYPE_UNKNOWN = 0x000000, /*< Initial value, can't be tested bitwisely */
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QUERY_TYPE_LOCAL_READ = 0x000001, /*< Read non-database data, execute in MaxScale:any */
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QUERY_TYPE_READ = 0x000002, /*< Read database data:any */
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QUERY_TYPE_WRITE = 0x000004, /*< Master data will be modified:master */
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QUERY_TYPE_MASTER_READ = 0x000008, /*< Read from the master:master */
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QUERY_TYPE_SESSION_WRITE = 0x000010, /*< Session data will be modified:master or all */
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QUERY_TYPE_USERVAR_WRITE = 0x000020, /*< Write a user variable:master or all */
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QUERY_TYPE_USERVAR_READ = 0x000040, /*< Read a user variable:master or any */
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QUERY_TYPE_SYSVAR_READ = 0x000080, /*< Read a system variable:master or any */
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/** Not implemented yet */
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//QUERY_TYPE_SYSVAR_WRITE = 0x000100, /*< Write a system variable:master or all */
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QUERY_TYPE_GSYSVAR_READ = 0x000200, /*< Read global system variable:master or any */
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QUERY_TYPE_GSYSVAR_WRITE = 0x000400, /*< Write global system variable:master or all */
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QUERY_TYPE_BEGIN_TRX = 0x000800, /*< BEGIN or START TRANSACTION */
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QUERY_TYPE_ENABLE_AUTOCOMMIT = 0x001000, /*< SET autocommit=1 */
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QUERY_TYPE_DISABLE_AUTOCOMMIT = 0x002000, /*< SET autocommit=0 */
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QUERY_TYPE_ROLLBACK = 0x004000, /*< ROLLBACK */
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QUERY_TYPE_COMMIT = 0x008000, /*< COMMIT */
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QUERY_TYPE_PREPARE_NAMED_STMT = 0x010000, /*< Prepared stmt with name from user:all */
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QUERY_TYPE_PREPARE_STMT = 0x020000, /*< Prepared stmt with id provided by server:all */
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QUERY_TYPE_EXEC_STMT = 0x040000, /*< Execute prepared statement:master or any */
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QUERY_TYPE_CREATE_TMP_TABLE = 0x080000, /*< Create temporary table:master (could be all) */
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QUERY_TYPE_READ_TMP_TABLE = 0x100000, /*< Read temporary table:master (could be any) */
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QUERY_TYPE_SHOW_DATABASES = 0x200000, /*< Show list of databases */
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QUERY_TYPE_SHOW_TABLES = 0x400000 /*< Show list of tables */
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} qc_query_type_t;
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/**
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* qc_query_op_t defines the operations a particular statement can perform.
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*/
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typedef enum qc_query_op
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{
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QUERY_OP_UNDEFINED = 0,
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QUERY_OP_SELECT = (1 << 0),
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QUERY_OP_UPDATE = (1 << 1),
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QUERY_OP_INSERT = (1 << 2),
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QUERY_OP_DELETE = (1 << 3),
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QUERY_OP_TRUNCATE = (1 << 4),
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QUERY_OP_ALTER = (1 << 5),
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QUERY_OP_CREATE = (1 << 6),
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QUERY_OP_DROP = (1 << 7),
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QUERY_OP_CHANGE_DB = (1 << 8),
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QUERY_OP_LOAD = (1 << 9),
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QUERY_OP_GRANT = (1 << 10),
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QUERY_OP_REVOKE = (1 << 11),
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QUERY_OP_CALL = (1 << 12),
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} qc_query_op_t;
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/**
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* qc_parse_result_t defines the possible outcomes when a statement is parsed.
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*/
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typedef enum qc_parse_result
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{
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QC_QUERY_INVALID = 0, /*< The query was not recognized or could not be parsed. */
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QC_QUERY_TOKENIZED = 1, /*< The query was classified based on tokens; incompletely classified. */
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QC_QUERY_PARTIALLY_PARSED = 2, /*< The query was only partially parsed; incompletely classified. */
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QC_QUERY_PARSED = 3 /*< The query was fully parsed; completely classified. */
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} qc_parse_result_t;
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/**
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* qc_field_usage_t defines where a particular field appears.
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*
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* QC_USED_IN_SELECT : The field appears on the left side of FROM in a top-level SELECT statement.
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* QC_USED_IN_SUBSELECT: The field appears on the left side of FROM in a sub-select SELECT statement.
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* QC_USED_IN_WHERE : The field appears in a WHERE clause.
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* QC_USED_IN_SET : The field appears in the SET clause of an UPDATE statement.
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* QC_USED_IN_GROUP_BY : The field appears in a GROUP BY clause.
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*
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* Note that multiple bits may be set at the same time. For instance, for a statement like
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* "SELECT fld FROM tbl WHERE fld = 1 GROUP BY fld", the bits QC_USED_IN_SELECT, QC_USED_IN_WHERE
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* and QC_USED_IN_GROUP_BY will be set.
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*/
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typedef enum qc_field_usage
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{
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QC_USED_IN_SELECT = 0x01, /*< SELECT fld FROM... */
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QC_USED_IN_SUBSELECT = 0x02, /*< SELECT 1 FROM ... SELECT fld ... */
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QC_USED_IN_WHERE = 0x04, /*< SELECT ... FROM ... WHERE fld = ... */
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QC_USED_IN_SET = 0x08, /*< UPDATE ... SET fld = ... */
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QC_USED_IN_GROUP_BY = 0x10, /*< ... GROUP BY fld */
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} qc_field_usage_t;
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/**
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* QC_FIELD_INFO contains information about a field used in a statement.
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*/
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typedef struct qc_field_info
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{
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char* database; /** Present if the field is of the form "a.b.c", NULL otherwise. */
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char* table; /** Present if the field is of the form "a.b", NULL otherwise. */
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char* column; /** Always present. */
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uint32_t usage; /** Bitfield denoting where the column appears. */
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} QC_FIELD_INFO;
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/**
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* QC_FUNCTION_INFO contains information about a function used in a statement.
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*/
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typedef struct qc_function_info
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{
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char* name; /** Name of function. */
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uint32_t usage; /** Bitfield denoting where the column appears. */
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} QC_FUNCTION_INFO;
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/**
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* Each API function returns @c QC_RESULT_OK if the actual parsing process
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* succeeded, and some error code otherwise.
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*/
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typedef enum qc_result
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{
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QC_RESULT_OK,
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QC_RESULT_ERROR
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} qc_result_t;
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/**
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* QUERY_CLASSIFIER defines the object a query classifier plugin must
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* implement and return.
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*
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* To a user of the query classifier functionality, it can in general
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* be ignored.
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*/
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typedef struct query_classifier
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{
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/**
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* Called once to setup the query classifier
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*
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* @param args The value of `query_classifier_args` in the configuration file.
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*
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* @return QC_RESULT_OK, if the query classifier could be setup, otherwise
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* some specific error code.
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*/
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int32_t (*qc_setup)(const char* args);
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/**
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* Called once at process startup, after @c qc_setup has successfully
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* been called.
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*
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* @return QC_RESULT_OK, if the process initialization succeeded.
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*/
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int32_t (*qc_process_init)(void);
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/**
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* Called once at process shutdown.
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*/
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void (*qc_process_end)(void);
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/**
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* Called once per each thread, except for the thread for which @c qc_process_init
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* was called.
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*
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* @return QC_RESULT_OK, if the thread initialization succeeded.
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*/
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int32_t (*qc_thread_init)(void);
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/**
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* Called once when a thread finishes, except for the thread for which @c qc_process_init
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* was called.
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*/
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void (*qc_thread_end)(void);
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/**
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* Called to explicitly parse a statement.
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*
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* @param stmt The statement to be parsed.
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* @param collect A bitmask of @c qc_collect_info_t values. Specifies what information
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* should be collected. Only a hint and must not restrict what information
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* later can be queried.
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* @param result On return, the parse result, if @c QC_RESULT_OK is returned.
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*
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* @return QC_RESULT_OK, if the parsing was not aborted due to resource
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* exhaustion or equivalent.
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*/
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int32_t (*qc_parse)(GWBUF* stmt, uint32_t collect, int32_t* result);
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/**
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* Reports the type of the statement.
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*
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* @param stmt A COM_QUERY or COM_STMT_PREPARE packet.
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* @param type On return, the type mask (combination of @c qc_query_type_t),
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* if @c QC_RESULT_OK is returned.
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*
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* @return QC_RESULT_OK, if the parsing was not aborted due to resource
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* exhaustion or equivalent.
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*/
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int32_t (*qc_get_type_mask)(GWBUF* stmt, uint32_t* type);
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/**
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* Reports the operation of the statement.
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*
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* @param stmt A COM_QUERY or COM_STMT_PREPARE packet.
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* @param type On return, the operation (one of @c qc_query_op_t), if
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* @c QC_RESULT_OK is returned.
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*
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* @return QC_RESULT_OK, if the parsing was not aborted due to resource
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* exhaustion or equivalent.
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*/
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int32_t (*qc_get_operation)(GWBUF* stmt, int32_t* op);
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/**
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* Reports the name of a created table.
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*
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* @param stmt A COM_QUERY or COM_STMT_PREPARE packet.
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* @param name On return, the name of the created table, if
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* @c QC_RESULT_OK is returned.
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*
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* @return QC_RESULT_OK, if the parsing was not aborted due to resource
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* exhaustion or equivalent.
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*/
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int32_t (*qc_get_created_table_name)(GWBUF* stmt, char** name);
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/**
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* Reports whether a statement is a "DROP TABLE ..." statement.
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*
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* @param stmt A COM_QUERY or COM_STMT_PREPARE packet
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* @param is_drop_table On return, non-zero if the statement is a DROP TABLE
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* statement, if @c QC_RESULT_OK is returned.
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*
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* @return QC_RESULT_OK, if the parsing was not aborted due to resource
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* exhaustion or equivalent.
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*/
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int32_t (*qc_is_drop_table_query)(GWBUF* stmt, int32_t* is_drop_table);
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/**
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* Returns all table names.
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*
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* @param stmt A COM_QUERY or COM_STMT_PREPARE packet.
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* @param fullnames If non-zero, the full (i.e. qualified) names are returned.
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* @param names On return, the names of the statement, if @c QC_RESULT_OK
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* is returned.
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* @param n_names On return, how many names were returned, if @c QC_RESULT_OK
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* is returned.
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*
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* @return QC_RESULT_OK, if the parsing was not aborted due to resource
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* exhaustion or equivalent.
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*/
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int32_t (*qc_get_table_names)(GWBUF* stmt, int32_t full_names, char*** names, int32_t *n_names);
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/**
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* The canonical version of a statement.
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*
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* @param stmt A COM_QUERY or COM_STMT_PREPARE packet.
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* @param canonical On return, the canonical version of the statement, if @c QC_RESULT_OK
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* is returned.
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*
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* @return QC_RESULT_OK, if the parsing was not aborted due to resource
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* exhaustion or equivalent.
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*/
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int32_t (*qc_get_canonical)(GWBUF* stmt, char** canonical);
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/**
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* Reports whether the statement has a where clause.
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*
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* @param stmt A COM_QUERY or COM_STMT_PREPARE packet.
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* @param has_clause On return, non-zero if the statement has a where clause, if
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* @c QC_RESULT_OK is returned.
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*
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* @return QC_RESULT_OK, if the parsing was not aborted due to resource
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* exhaustion or equivalent.
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*/
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int32_t (*qc_query_has_clause)(GWBUF* stmt, int32_t* has_clause);
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/**
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* Reports the database names.
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*
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* @param stmt A COM_QUERY or COM_STMT_PREPARE packet.
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* @param names On return, the database names, if
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* @c QC_RESULT_OK is returned.
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* @param size On return, the number of names in @names, if
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* @c QC_RESULT_OK is returned.
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*
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* @return QC_RESULT_OK, if the parsing was not aborted due to resource
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* exhaustion or equivalent.
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*/
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int32_t (*qc_get_database_names)(GWBUF* stmt, char*** names, int32_t* size);
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/**
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* Reports the prepare name.
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*
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* @param stmt A COM_QUERY or COM_STMT_PREPARE packet.
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* @param name On return, the name of a prepare statement, if
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* @c QC_RESULT_OK is returned.
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*
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* @return QC_RESULT_OK, if the parsing was not aborted due to resource
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* exhaustion or equivalent.
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*/
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int32_t (*qc_get_prepare_name)(GWBUF* stmt, char** name);
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/**
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* Reports field information.
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*
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* @param stmt A COM_QUERY or COM_STMT_PREPARE packet.
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* @param infos On return, array of field infos, if @c QC_RESULT_OK is returned.
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* @param n_infos On return, the size of @c infos, if @c QC_RESULT_OK is returned.
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*
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* @return QC_RESULT_OK, if the parsing was not aborted due to resource
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* exhaustion or equivalent.
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*/
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int32_t (*qc_get_field_info)(GWBUF* stmt, const QC_FIELD_INFO** infos, uint32_t* n_infos);
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/**
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* The canonical version of a statement.
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*
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* @param stmt A COM_QUERY or COM_STMT_PREPARE packet.
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* @param infos On return, array of function infos, if @c QC_RESULT_OK is returned.
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* @param n_infos On return, the size of @c infos, if @c QC_RESULT_OK is returned.
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*
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* @return QC_RESULT_OK, if the parsing was not aborted due to resource
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* exhaustion or equivalent.
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*/
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int32_t (*qc_get_function_info)(GWBUF* stmt, const QC_FUNCTION_INFO** infos, uint32_t* n_infos);
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/**
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* Return the preparable statement of a PREPARE statement.
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*
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* @param stmt A COM_QUERY or COM_STMT_PREPARE packet.
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* @param preparable_stmt On return, the preparable statement (provided @c stmt is a
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* PREPARE statement), if @c QC_RESULT_OK is returned. Otherwise
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* NULL.
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*
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* @attention The returned GWBUF is the property of @c stmt and will be deleted when
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* @c stmt is. If the preparable statement need to be retained beyond the
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* lifetime of @c stmt, it must be cloned.
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*
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* @return QC_RESULT_OK, if the parsing was not aborted due to resource
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* exhaustion or equivalent.
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*/
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int32_t (*qc_get_preparable_stmt)(GWBUF* stmt, GWBUF** preparable_stmt);
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} QUERY_CLASSIFIER;
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/**
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* Loads and sets up the default query classifier.
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*
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* This must be called once during the execution of a process. The query
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* classifier functions can only be used if this function first and thereafter
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* the @c qc_process_init return true.
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*
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* MaxScale calls this function, so plugins should not do that.
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*
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* @param plugin_name The name of the plugin from which the query classifier
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* should be loaded.
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* @param plugin_args The arguments to be provided to the query classifier.
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*
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* @return True if the query classifier could be loaded and initialized,
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* false otherwise.
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*
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* @see qc_end qc_thread_init
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*/
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bool qc_setup(const char* plugin_name, const char* plugin_args);
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/**
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* Intializes the query classifier.
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*
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* This function should be called once, provided @c qc_setup returned true,
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* before the query classifier functionality is used.
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*
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* MaxScale calls this functions, so plugins should not do that.
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*
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* @param kind What kind of initialization should be performed.
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* Combination of qc_init_kind_t.
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*
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* @return True, if the process wide initialization could be performed.
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*
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* @see qc_process_end qc_thread_init
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*/
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bool qc_process_init(uint32_t kind);
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/**
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* Finalizes the query classifier.
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*
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* A successful call of qc_init() should before program exit be followed
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* by a call to this function. MaxScale calls this function, so plugins
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* should not do that.
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*
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* @param kind What kind of finalization should be performed.
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* Combination of qc_init_kind_t.
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*
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* @see qc_process_init qc_thread_end
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*/
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void qc_process_end(uint32_t kind);
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/**
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* Loads a particular query classifier.
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*
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* In general there is no need to use this function, but rely upon qc_init().
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* However, if there is a need to use multiple query classifiers concurrently
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* then this function provides the means for that. Note that after a query
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* classifier has been loaded, it must explicitly be initialized before it
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* can be used.
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*
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* @param plugin_name The name of the plugin from which the query classifier
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* should be loaded.
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*
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* @return A QUERY_CLASSIFIER object if successful, NULL otherwise.
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*
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* @see qc_unload
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*/
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QUERY_CLASSIFIER* qc_load(const char* plugin_name);
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/**
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* Unloads an explicitly loaded query classifier.
|
|
*
|
|
* @see qc_load
|
|
*/
|
|
void qc_unload(QUERY_CLASSIFIER* classifier);
|
|
|
|
/**
|
|
* Performs thread initialization needed by the query classifier. Should
|
|
* be called in every thread, except the one where qc_process_init()
|
|
* was called.
|
|
*
|
|
* MaxScale calls this function, so plugins should not do that.
|
|
*
|
|
* @param kind What kind of initialization should be performed.
|
|
* Combination of qc_init_kind_t.
|
|
*
|
|
* @return True if the initialization succeeded, false otherwise.
|
|
*
|
|
* @see qc_thread_end
|
|
*/
|
|
bool qc_thread_init(uint32_t kind);
|
|
|
|
/**
|
|
* Performs thread finalization needed by the query classifier.
|
|
* A successful call to qc_thread_init() should at some point be followed
|
|
* by a call to this function.
|
|
*
|
|
* MaxScale calls this function, so plugins should not do that.
|
|
*
|
|
* @param kind What kind of finalization should be performed.
|
|
* Combination of qc_init_kind_t.
|
|
*
|
|
* @see qc_thread_init
|
|
*/
|
|
void qc_thread_end(uint32_t kind);
|
|
|
|
/**
|
|
* Parses the statement in the provided buffer and returns a value specifying
|
|
* to what extent the statement could be parsed.
|
|
*
|
|
* There is no need to call this function explicitly before calling any of
|
|
* the other functions; e.g. qc_get_type_mask(). When some particular property of
|
|
* a statement is asked for, the statement will be parsed if it has not been
|
|
* parsed yet. Also, if the statement in the provided buffer has been parsed
|
|
* already then this function will only return the result of that parsing;
|
|
* the statement will not be parsed again.
|
|
*
|
|
* @param stmt A buffer containing an COM_QUERY or COM_STMT_PREPARE packet.
|
|
* @param collect A bitmask of @c qc_collect_info_t values. Specifies what information
|
|
* should be collected.
|
|
*
|
|
* Note that this is merely a hint and does not restrict what
|
|
* information can be queried for. If necessary, the statement
|
|
* will transparently be reparsed.
|
|
*
|
|
* @return To what extent the statement could be parsed.
|
|
*/
|
|
qc_parse_result_t qc_parse(GWBUF* stmt, uint32_t collect);
|
|
|
|
/**
|
|
* Convert a qc_field_usage_t enum to corresponding string.
|
|
*
|
|
* @param usage The value to be converted
|
|
*
|
|
* @return The corresponding string. Must @b not be freed.
|
|
*/
|
|
const char* qc_field_usage_to_string(qc_field_usage_t usage);
|
|
|
|
/**
|
|
* Convert a mask of qc_field_usage_t enum values to corresponding string.
|
|
*
|
|
* @param usage_mask Mask of qc_field_usage_t values.
|
|
*
|
|
* @return The corresponding string, or NULL if memory allocation fails.
|
|
* @b Must be freed by the caller.
|
|
*/
|
|
char* qc_field_usage_mask_to_string(uint32_t usage_mask);
|
|
|
|
/**
|
|
* Returns information about affected fields.
|
|
*
|
|
* @param stmt A buffer containing a COM_QUERY or COM_STMT_PREPARE packet.
|
|
* @param infos Pointer to pointer that after the call will point to an
|
|
* array of QC_FIELD_INFO:s.
|
|
* @param n_infos Pointer to size_t variable where the number of items
|
|
* in @c infos will be returned.
|
|
*
|
|
* @note The returned array belongs to the GWBUF and remains valid for as
|
|
* long as the GWBUF is valid. If the data is needed for longer than
|
|
* that, it must be copied.
|
|
*/
|
|
void qc_get_field_info(GWBUF* stmt, const QC_FIELD_INFO** infos, size_t* n_infos);
|
|
|
|
/**
|
|
* Returns information about function usage.
|
|
*
|
|
* @param stmt A buffer containing a COM_QUERY or COM_STMT_PREPARE packet.
|
|
* @param infos Pointer to pointer that after the call will point to an
|
|
* array of QC_FUNCTION_INFO:s.
|
|
* @param n_infos Pointer to size_t variable where the number of items
|
|
* in @c infos will be returned.
|
|
*
|
|
* @note The returned array belongs to the GWBUF and remains valid for as
|
|
* long as the GWBUF is valid. If the data is needed for longer than
|
|
* that, it must be copied.
|
|
*/
|
|
void qc_get_function_info(GWBUF* stmt, const QC_FUNCTION_INFO** infos, size_t* n_infos);
|
|
|
|
/**
|
|
* Returns the statement, with literals replaced with question marks.
|
|
*
|
|
* @param stmt A buffer containing a COM_QUERY or COM_STMT_PREPARE packet.
|
|
*
|
|
* @return A statement in its canonical form, or NULL if a memory
|
|
* allocation fails. The string must be freed by the caller.
|
|
*/
|
|
char* qc_get_canonical(GWBUF* stmt);
|
|
|
|
/**
|
|
* Returns the name of the created table.
|
|
*
|
|
* @param stmt A buffer containing a COM_QUERY or COM_STMT_PREPARE packet.
|
|
*
|
|
* @return The name of the created table or NULL if the statement
|
|
* does not create a table or a memory allocation failed.
|
|
* The string must be freed by the caller.
|
|
*/
|
|
char* qc_get_created_table_name(GWBUF* stmt);
|
|
|
|
/**
|
|
* Returns the databases accessed by the statement. Note that a
|
|
* possible default database is not returned.
|
|
*
|
|
* @param stmt A buffer containing a COM_QUERY or COM_STMT_PREPARE packet.
|
|
* @param size Pointer to integer where the number of databases
|
|
* is stored.
|
|
*
|
|
* @return Array of strings or NULL if a memory allocation fails.
|
|
*
|
|
* @note The returned array and the strings pointed to @b must be freed
|
|
* by the caller.
|
|
*/
|
|
char** qc_get_database_names(GWBUF* stmt, int* size);
|
|
|
|
/**
|
|
* Returns the operation of the statement.
|
|
*
|
|
* @param stmt A buffer containing a COM_QUERY or COM_STMT_PREPARE packet.
|
|
*
|
|
* @return The operation of the statement.
|
|
*/
|
|
qc_query_op_t qc_get_operation(GWBUF* stmt);
|
|
|
|
/**
|
|
* Returns the name of the prepared statement, if the statement
|
|
* is a PREPARE or EXECUTE statement.
|
|
*
|
|
* @param stmt A buffer containing a COM_QUERY or COM_STMT_PREPARE packet.
|
|
*
|
|
* @return The name of the prepared statement, if the statement
|
|
* is a PREPARE or EXECUTE statement; otherwise NULL.
|
|
*
|
|
* @note The returned string @b must be freed by the caller.
|
|
*
|
|
* @note Even though a COM_STMT_PREPARE can be given to the query
|
|
* classifier for parsing, this function will in that case
|
|
* return NULL since the id of the statement is provided by
|
|
* the server.
|
|
*/
|
|
char* qc_get_prepare_name(GWBUF* stmt);
|
|
|
|
/**
|
|
* Returns the preparable statement of a PREPARE statment. Other query classifier
|
|
* functions can then be used on the returned statement to find out information
|
|
* about the preparable statement. The returned @c GWBUF should not be used for
|
|
* anything else but for obtaining information about the preparable statement.
|
|
*
|
|
* @param stmt A buffer containing a COM_QUERY or COM_STMT_PREPARE packet.
|
|
*
|
|
* @return The preparable statement, if @stmt was a COM_QUERY PREPARE statement,
|
|
* or NULL.
|
|
*
|
|
* @attention If the packet was a COM_STMT_PREPARE, then this function will
|
|
* return NULL and the actual properties of the query can be obtained
|
|
* by calling any of the qc-functions directly on the GWBUF containing
|
|
* the COM_STMT_PREPARE. However, the type mask will contain the
|
|
* bit @c QUERY_TYPE_PREPARE_STMT.
|
|
*
|
|
* @attention The returned @c GWBUF is the property of @c stmt and will be
|
|
* deleted along with it.
|
|
*/
|
|
GWBUF* qc_get_preparable_stmt(GWBUF* stmt);
|
|
|
|
/**
|
|
* Returns the tables accessed by the statement.
|
|
*
|
|
* @param stmt A buffer containing a COM_QUERY or COM_STMT_PREPARE packet.
|
|
* @param tblsize Pointer to integer where the number of tables is stored.
|
|
* @param fullnames If true, a table names will include the database name
|
|
* as well (if explicitly referred to in the statement).
|
|
*
|
|
* @return Array of strings or NULL if a memory allocation fails.
|
|
*
|
|
* @note The returned array and the strings pointed to @b must be freed
|
|
* by the caller.
|
|
*/
|
|
char** qc_get_table_names(GWBUF* stmt, int* size, bool fullnames);
|
|
|
|
|
|
/**
|
|
* Returns a bitmask specifying the type(s) of the statement. The result
|
|
* should be tested against specific qc_query_type_t values* using the
|
|
* bitwise & operator, never using the == operator.
|
|
*
|
|
* @param stmt A buffer containing a COM_QUERY or COM_STMT_PREPARE packet.
|
|
*
|
|
* @return A bitmask with the type(s) the query.
|
|
*
|
|
* @see qc_query_is_type
|
|
*/
|
|
uint32_t qc_get_type_mask(GWBUF* stmt);
|
|
|
|
/**
|
|
* Returns the type bitmask of transaction related statements.
|
|
*
|
|
* If the statement starts a transaction, ends a transaction or
|
|
* changes the autocommit state, the returned bitmap will be a
|
|
* combination of:
|
|
*
|
|
* QUERY_TYPE_BEGIN_TRX
|
|
* QUERY_TYPE_COMMIT
|
|
* QUERY_TYPE_ROLLBACK
|
|
* QUERY_TYPE_ENABLE_AUTOCOMMIT
|
|
* QUERY_TYPE_DISABLE_AUTOCOMMIT
|
|
* QUERY_TYPE_READ (explicitly read only transaction)
|
|
* QUERY_TYPE_WRITE (explicitly read write transaction)
|
|
*
|
|
* Otherwise the result will be 0.
|
|
*
|
|
* @param stmt A COM_QUERY or COM_STMT_PREPARE packet.
|
|
*
|
|
* @return The relevant type bits if the statement is transaction
|
|
* related, otherwise 0.
|
|
*/
|
|
uint32_t qc_get_trx_type_mask(GWBUF* stmt);
|
|
|
|
/**
|
|
* Returns whether the statement is a DROP TABLE statement.
|
|
*
|
|
* @param stmt A buffer containing a COM_QUERY or COM_STMT_PREPARE packet.
|
|
*
|
|
* @return True if the statement is a DROP TABLE statement, false otherwise.
|
|
*
|
|
* @todo This function is far too specific.
|
|
*/
|
|
bool qc_is_drop_table_query(GWBUF* stmt);
|
|
|
|
/**
|
|
* Returns the string representation of a query operation.
|
|
*
|
|
* @param op A query operation.
|
|
*
|
|
* @return The corresponding string.
|
|
*
|
|
* @note The returned string is statically allocated and must *not* be freed.
|
|
*/
|
|
const char* qc_op_to_string(qc_query_op_t op);
|
|
|
|
/**
|
|
* Returns whether the typemask contains a particular type.
|
|
*
|
|
* @param typemask A bitmask of query types.
|
|
* @param type A particular qc_query_type_t value.
|
|
*
|
|
* @return True, if the type is in the mask.
|
|
*/
|
|
static inline bool qc_query_is_type(uint32_t typemask, qc_query_type_t type)
|
|
{
|
|
return (typemask & (uint32_t)type) == (uint32_t)type;
|
|
}
|
|
|
|
/**
|
|
* Returns whether the statement has a WHERE or a USING clause.
|
|
*
|
|
* @param stmt A buffer containing a COM_QUERY or COM_STMT_PREPARE packet.
|
|
*
|
|
* @return True, if the statement has a WHERE or USING clause, false
|
|
* otherwise.
|
|
*/
|
|
bool qc_query_has_clause(GWBUF* stmt);
|
|
|
|
/**
|
|
* Returns the string representation of a query type.
|
|
*
|
|
* @param type A query type (not a bitmask of several).
|
|
*
|
|
* @return The corresponding string.
|
|
*
|
|
* @note The returned string is statically allocated and must @b not be freed.
|
|
*/
|
|
const char* qc_type_to_string(qc_query_type_t type);
|
|
|
|
/**
|
|
* Returns a string representation of a type bitmask.
|
|
*
|
|
* @param typemask A bit mask of query types.
|
|
*
|
|
* @return The corresponding string or NULL if the allocation fails.
|
|
*
|
|
* @note The returned string is dynamically allocated and @b must be freed.
|
|
*/
|
|
char* qc_typemask_to_string(uint32_t typemask);
|
|
|
|
MXS_END_DECLS
|