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/*
 * Copyright (C) 2015 Archie L. Cobbs. All rights reserved.
 */

package org.jsimpledb.kv.mysql;

import com.mysql.jdbc.MysqlErrorNumbers;
import com.mysql.jdbc.exceptions.MySQLTimeoutException;

import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;

import org.jsimpledb.kv.KVTransactionException;
import org.jsimpledb.kv.RetryTransactionException;
import org.jsimpledb.kv.sql.SQLKVDatabase;
import org.jsimpledb.kv.sql.SQLKVTransaction;

/**
 * MySQL variant of {@link SQLKVDatabase}.
 *
 * 

* Automatically creates the key/value table on startup if it doesn't already exist. */ public class MySQLKVDatabase extends SQLKVDatabase { public static final int INNODB_NORMAL_INDEX_SIZE = 767; public static final int INNODB_LARGE_INDEX_SIZE = 3072; private static final int DEFAULT_LOCK_TIMEOUT = 10; // 10 seconds private boolean innodbLargePrefix; /** * Configure the use of InnoDB large prefixes. * *

* MySQL InnoDB indexes are normally limited to {@value #INNODB_NORMAL_INDEX_SIZE} bytes, but you can * go up to {@value #INNODB_LARGE_INDEX_SIZE} bytes if you set these parameters in {@code /etc/my.cnf}: *

     *  [mysqld]
     *  innodb_large_prefix      = true
     *  innodb_file_per_table    = true
     *  innodb_file_format       = barracuda
     * 
* *

* Setting this property to true increases the maximum key length from {@value #INNODB_NORMAL_INDEX_SIZE} * to {@value #INNODB_LARGE_INDEX_SIZE} bytes and adds {@code ROW_FORMAT=DYNAMIC} to the table creation * statement in {@link #initializeDatabaseIfNecessary initializeDatabaseIfNecessary()}. This property has * no effect if the table already exists at startup. * *

* Default is false. * * @param innodbLargePrefix true for InnoDB large prefixes * @see Limits on InnoDB Tables */ public void setInnodbLargePrefix(boolean innodbLargePrefix) { this.innodbLargePrefix = innodbLargePrefix; } @Override protected void initializeDatabaseIfNecessary(Connection connection) throws SQLException { final int indexSize = this.innodbLargePrefix ? INNODB_LARGE_INDEX_SIZE : INNODB_NORMAL_INDEX_SIZE; final String rowFormat = this.innodbLargePrefix ? " ROW_FORMAT=DYNAMIC" : ""; final String sql = "CREATE TABLE IF NOT EXISTS " + this.quote(this.getTableName()) + " (\n" + " " + this.quote(this.getKeyColumnName()) + " VARBINARY(" + indexSize + ") NOT NULL,\n" + " " + this.quote(this.getValueColumnName()) + " LONGBLOB NOT NULL,\n" + " PRIMARY KEY(" + this.quote(this.getKeyColumnName()) + ")\n" + ") ENGINE=InnoDB default charset=utf8 collate=utf8_bin" + rowFormat; try (final Statement statement = connection.createStatement()) { this.log.debug("auto-creating table `" + this.getTableName() + "' if not already existing:\n{}", sql); statement.execute(sql); } } @Override protected void preBeginTransaction(Connection connection) throws SQLException { try (final Statement statement = connection.createStatement()) { statement.execute("SET innodb_lock_wait_timeout = " + DEFAULT_LOCK_TIMEOUT); statement.execute("SET SESSION sql_mode = 'TRADITIONAL'"); // force error if key or value is too long } } @Override protected SQLKVTransaction createSQLKVTransaction(Connection connection) throws SQLException { return new MySQLKVTransaction(this, connection); } /** * Encloses the given {@code name} in backticks. */ @Override public String quote(String name) { return "`" + name + "`"; } /** * Appends {@code LIMIT 1} to the statement. */ @Override public String limitSingleRow(String sql) { return sql + " LIMIT 1"; } @Override public KVTransactionException wrapException(SQLKVTransaction tx, SQLException e) { switch (e.getErrorCode()) { case MysqlErrorNumbers.ER_LOCK_WAIT_TIMEOUT: return new RetryTransactionException(tx, e); case MysqlErrorNumbers.ER_LOCK_DEADLOCK: return new RetryTransactionException(tx, e); default: if (e instanceof MySQLTimeoutException) return new RetryTransactionException(tx, e); return super.wrapException(tx, e); } } }





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