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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
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* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
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* Copyright (C) 2009 Sun Microsystems
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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#ifndef DRIZZLED_PLUGIN_INFO_SCHEMA_TABLE_H
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#define DRIZZLED_PLUGIN_INFO_SCHEMA_TABLE_H
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#include "drizzled/plugin/plugin.h"
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#include "drizzled/algorithm/crc32.h"
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#include "drizzled/common.h"
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typedef struct drizzle_lex_string LEX_STRING;
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extern const std::string INFORMATION_SCHEMA_NAME;
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* Header file which contains all classes related to I_S
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typedef class Item COND;
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class InfoSchemaTable;
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* Represents a field (column) in an I_S table.
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ColumnInfo(const std::string& in_name,
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enum enum_field_types in_type,
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const std::string& in_old_name)
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type(DRIZZLE_TYPE_VARCHAR),
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* @return the name of this column.
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const std::string &getName() const
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* This method is only ever called from the
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* InfoSchemaMethods::oldFormat() methods. It is mostly
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* for old SHOW compatability. It is used when a list
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* of fields need to be generated for SHOW. The names
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* for those fields (or columns) are found by calling
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* this method on each column in the I_S table.
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* @return the old name of this column.
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const std::string &getOldName() const
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* @return the flags for this column.
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uint32_t getFlags() const
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* @return the length of this column.
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uint32_t getLength() const
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* @return the value of this column.
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int32_t getValue() const
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* @return this column's type.
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enum enum_field_types getType() const
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* This is used as column name.
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const std::string name;
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* For string-type columns, this is the maximum number of
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* characters. Otherwise, it is the 'display-length' for the column.
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* This denotes data type for the column. For the most part, there seems to
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* be one entry in the enum for each SQL data type, although there seem to
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* be a number of additional entries in the enum.
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enum enum_field_types type;
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* This is used to set column attributes. By default, columns are @c NOT
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* @c NULL and @c SIGNED, and you can deviate from the default
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* by setting the appopriate flags. You can use either one of the flags
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* @c MY_I_S_MAYBE_NULL and @cMY_I_S_UNSIGNED or
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* combine them using the bitwise or operator @c |. Both flags are
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* defined in table.h.
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* The name of this column which is used for old SHOW
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const std::string old_name;
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* @class InfoSchemaMethods
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* The methods that an I_S table can support
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class InfoSchemaMethods
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virtual ~InfoSchemaMethods() {}
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virtual int fillTable(Session *session,
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InfoSchemaTable *schema_table);
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virtual int processTable(InfoSchemaTable *store_table,
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Session *session, TableList *tables,
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Table *table, bool res, LEX_STRING *db_name,
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LEX_STRING *table_name);
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virtual int oldFormat(Session *session,
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InfoSchemaTable *schema_table) const;
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* @class InfoSchemaRecord
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* @brief represents a row in an I_S table
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class InfoSchemaRecord
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InfoSchemaRecord(unsigned char *buf, size_t in_len);
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InfoSchemaRecord(const InfoSchemaRecord &rhs);
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* Copy this record into the memory passed to this function.
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* @param[out] buf copy the record into this memory
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void copyRecordInto(unsigned char *buf)
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memcpy(buf, record, rec_len);
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* @return the length of this record
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size_t getRecordLength() const
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* @return the checksum of the data in this record
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uint32_t getChecksum() const
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* @param[in] crc a checksum to compare
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* @return true if the input checksum matches the checksum for this record; false otherwise
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bool checksumMatches(uint32_t crc) const
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return (checksum == crc);
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unsigned char *record;
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inline void operator()(const T *ptr) const
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class FindRowByChecksum
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FindRowByChecksum(uint32_t in_cs)
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inline bool operator()(const InfoSchemaRecord *rec) const
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return (cs == rec->getChecksum());
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* @class InfoSchemaTable
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* Represents an I_S table.
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class InfoSchemaTable : public Plugin
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InfoSchemaTable(const InfoSchemaTable &);
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InfoSchemaTable& operator=(const InfoSchemaTable &);
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typedef std::vector<const ColumnInfo *> Columns;
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typedef std::vector<InfoSchemaRecord *> Rows;
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InfoSchemaTable(const std::string& tab_name,
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Columns& in_column_info,
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bool in_opt_possible,
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InfoSchemaMethods *in_methods)
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Plugin(tab_name, "InfoSchemaTable"),
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is_opt_possible(in_opt_possible),
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first_column_index(idx_col1),
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second_column_index(idx_col2),
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requested_object(req_object),
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column_info(in_column_info),
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i_s_methods(in_methods),
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InfoSchemaTable(const std::string& tab_name,
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Columns& in_column_info,
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bool in_opt_possible,
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InfoSchemaMethods *in_methods,
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const std::string in_plugin_name)
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Plugin(tab_name, "InfoSchemaTable"),
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is_opt_possible(in_opt_possible),
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first_column_index(idx_col1),
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second_column_index(idx_col2),
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requested_object(req_object),
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column_info(in_column_info),
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i_s_methods(in_methods),
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plugin_name(in_plugin_name)
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explicit InfoSchemaTable(const std::string& tab_name)
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Plugin(tab_name, "InfoSchemaTable"),
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is_opt_possible(false),
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first_column_index(0),
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second_column_index(0),
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virtual ~InfoSchemaTable()
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std::for_each(rows.begin(),
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* Set the methods available on this I_S table.
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* @param[in] new_methods the methods to use
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void setInfoSchemaMethods(InfoSchemaMethods *new_methods)
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i_s_methods= new_methods;
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* @param[in] session a session handler
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* @return 0 on success; 1 on error
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int fillTable(Session *session, Table *table)
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int retval= i_s_methods->fillTable(session, table, this);
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* Fill and store records into an I_S table.
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* @param[in] session a session handler
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* @param[in] tables table list (processed table)
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* @param[in] table I_S table
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* @param[in] res 1 means error during opening of the processed table
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* 0 means processed table opened without error
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* @param[in] db_name database name
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* @param[in] tab_name table name
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* @return 0 on success; 1 on error
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int processTable(Session *session, TableList *tables, Table *table,
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bool res, LEX_STRING *db_name, LEX_STRING *tab_name)
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int retval= i_s_methods->processTable(this, session, tables, table,
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res, db_name, tab_name);
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* For old SHOW compatibility. It is used when old SHOW doesn't
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* have generated column names. Generates the list of fields
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* @param[in] session a session handler
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* @param[in] schema_table pointer to element of the I_S tables list
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int oldFormat(Session *session, InfoSchemaTable *schema_table) const
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int retval= i_s_methods->oldFormat(session, schema_table);
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* @param[in] new_first_index value to set first column index to
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void setFirstColumnIndex(int32_t new_first_index)
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first_column_index= new_first_index;
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* @param[in] new_second_index value to set second column index to
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void setSecondColumnIndex(int32_t new_second_index)
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second_column_index= new_second_index;
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* @param[in] in_column_info the columns info to use for this I_S table
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void setColumnInfo(ColumnInfo *in_column_info)
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ColumnInfo *tmp= in_column_info;
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for (; tmp->getName().length() != 0; tmp++)
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column_info.push_back(tmp);
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* @return the name of the I_S table.
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const std::string &getTableName() const
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* @return the names of the I_S tables.
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static void getTableNames(std::set<std::string>& tables_names);
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* @return true if this I_S table is hidden; false otherwise.
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bool isHidden() const
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* @return true if I_S optimizations can be performed on this
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* I_S table when running the fillTable method; false
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bool isOptimizationPossible() const
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return is_opt_possible;
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* @return the index for the first field.
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int32_t getFirstColumnIndex() const
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return first_column_index;
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* @return the index the second field.
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int32_t getSecondColumnIndex() const
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return second_column_index;
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* @return the requested object.
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uint32_t getRequestedObject() const
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return requested_object;
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* @return the plugin name.
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const std::string &getPluginName() const
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* @return the columns for this I_S table
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const Columns &getColumns() const
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* @return the rows for this I_S table.
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* Clear the rows for this table and de-allocate all memory for this rows.
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std::for_each(rows.begin(),
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* Add a row to the std::vector of rows for this I_S table. For the moment, we check to make sure
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* that we do not add any duplicate rows. This is done in a niave manner for the moment by
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* checking the crc of the raw data for each row. We will not add this row to the std::vector of
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* rows for this I_S table is a duplicate row already exists in the std::vector.
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* @param[in] buf raw data for the record to add
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* @param[in] len size of the raw data for the record to add
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void addRow(unsigned char *buf, size_t len)
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uint32_t cs= algorithm::crc32((const char *) buf, len);
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Rows::iterator it= std::find_if(rows.begin(),
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FindRowByChecksum(cs));
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if (it == rows.end())
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InfoSchemaRecord *record= new InfoSchemaRecord(buf, len);
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rows.push_back(record);
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* @param[in] index the index of this column
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* @return the name for the column at the given index
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const std::string &getColumnName(int index) const
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return column_info[index]->getName();
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* Boolean which indicates whether this I_S table
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* is hidden or not. If it is hidden, it will not show
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* up in the list of I_S tables.
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* Boolean which indicates whether optimizations are
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* possible on this I_S table when performing the
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bool is_opt_possible;
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* The index of the first column.
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int32_t first_column_index;
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* The index of the second column.
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int32_t second_column_index;
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* The object to open (TABLE | VIEW).
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uint32_t requested_object;
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* The columns for this I_S table.
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* The rows for this I_S table.
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* Contains the methods available on this I_S table.
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InfoSchemaMethods *i_s_methods;
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* The name of the plugin associated with this I_S table
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* NULL for non I_S tables.
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const std::string plugin_name;
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static bool addPlugin(plugin::InfoSchemaTable *schema_table);
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static void removePlugin(plugin::InfoSchemaTable *table);
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static plugin::InfoSchemaTable *getTable(const char *table_name);
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static int addTableToList(Session *session, std::vector<LEX_STRING*> &files,
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} /* namespace plugin */
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} /* namespace drizzled */
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#endif /* DRIZZLED_PLUGIN_INFO_SCHEMA_TABLE_H */
added
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drizzled/plugin/info_schema_table.h
