/*
* Copyright Aduna (http://www.aduna-software.com/) (c) 2008.
*
* Licensed under the Aduna BSD-style license.
*/
package org.openrdf.sail.rdbms.schema;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Types;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Represents and controls the underlying database table.
*
* @author James Leigh
*/
public class RdbmsTable {
public static int total_opt;
public static int MAX_DELTA_TO_FORCE_OPTIMIZE = 10000;
private static final String[] TYPE_TABLE = new String[] { "TABLE" };
private Logger logger = LoggerFactory.getLogger(RdbmsTable.class);
private int addedCount;
private Connection conn;
private String name;
private int removedCount;
private long rowCount;
private PreparedStatement clear;
public RdbmsTable(String name) {
super();
this.name = name;
}
public void setConnection(Connection conn) {
this.conn = conn;
}
public void close()
throws SQLException
{
if (clear != null) {
clear.close();
}
}
public long size() {
assert rowCount >= 0 : rowCount;
return rowCount;
}
public void clear()
throws SQLException
{
if (clear == null) {
clear = conn.prepareStatement(buildClear());
}
clear.execute();
rowCount = 0;
}
public void createTable(CharSequence columns)
throws SQLException
{
execute(buildCreateTable(columns));
rowCount = 0;
}
public void createTransactionalTable(CharSequence columns)
throws SQLException
{
execute(buildCreateTransactionalTable(columns));
rowCount = 0;
}
public void createTemporaryTable(CharSequence columns)
throws SQLException
{
try {
execute(buildCreateTemporaryTable(columns));
}
catch (SQLException e) {
// must already exist
}
}
public void execute(String command)
throws SQLException
{
if (command != null) {
Statement st = conn.createStatement();
try {
st.execute(command);
}
catch (SQLException e) {
logger.warn(e.getMessage() + '\n' + command);
throw e;
}
finally {
st.close();
}
}
}
public int executeUpdate(String command, String... parameters)
throws SQLException
{
PreparedStatement st = conn.prepareStatement(command);
try {
for (int i = 0; i < parameters.length; i++) {
if (parameters[i] == null) {
st.setNull(i + 1, Types.VARCHAR);
}
else {
st.setString(i + 1, parameters[i]);
}
}
return st.executeUpdate();
}
catch (SQLException e) {
logger.warn(e.getMessage() + '\n' + command);
throw e;
}
finally {
st.close();
}
}
public String getCatalog() {
return null;
}
public String getName() {
return name;
}
public String getSchema() {
return null;
}
public void primaryIndex(String... columns)
throws SQLException
{
execute(buildPrimaryIndex(columns));
}
public void index(String... columns)
throws SQLException
{
if (columns.length == 1 && columns[0].equalsIgnoreCase("value")
&& getName().toUpperCase().contains("LONG_"))
{
execute(buildLongIndex(columns));
}
else {
execute(buildIndex(columns));
}
}
public void dropIndex(String name)
throws SQLException
{
execute(buildDropIndex(name));
}
public boolean isCreated()
throws SQLException
{
DatabaseMetaData metaData = conn.getMetaData();
String c = getCatalog();
String s = getSchema();
String n = getName();
ResultSet tables = metaData.getTables(c, s, n, TYPE_TABLE);
try {
return tables.next();
}
finally {
tables.close();
}
}
public Map<String, List<String>> getIndexes()
throws SQLException
{
DatabaseMetaData metaData = conn.getMetaData();
String c = getCatalog();
String s = getSchema();
String n = getName();
ResultSet indexes = metaData.getIndexInfo(c, s, n, false, false);
try {
Map<String, List<String>> names = new HashMap<String, List<String>>();
while (indexes.next()) {
String index = indexes.getString(6);
String column = indexes.getString(9);
List<String> columns = names.get(index);
if (columns == null) {
names.put(index, columns = new ArrayList<String>());
}
columns.add(column);
}
return names;
}
finally {
indexes.close();
}
}
public long count()
throws SQLException
{
StringBuilder sb = new StringBuilder();
sb.append("SELECT COUNT(*)\n");
sb.append("FROM ").append(name);
String query = sb.toString();
Statement st = conn.createStatement();
try {
ResultSet rs = st.executeQuery(query);
try {
if (rs.next()) {
rowCount = rs.getLong(1);
assert rowCount >= 0 : rowCount;
return rowCount;
}
return 0;
}
finally {
rs.close();
}
}
finally {
st.close();
}
}
public void modified(int inserted, int deleted)
throws SQLException
{
if (inserted < 1 && deleted < 1) {
return;
}
addedCount += inserted;
removedCount += deleted;
rowCount += inserted - deleted;
assert rowCount >= 0 : rowCount;
}
public void optimize()
throws SQLException
{
if (optimize(addedCount + removedCount, rowCount)) {
execute(buildOptimize());
addedCount = removedCount = 0;
total_opt += 1;
}
}
public PreparedStatement prepareStatement(String sql)
throws SQLException
{
return conn.prepareStatement(sql);
}
public void rollback()
throws SQLException
{
conn.rollback();
}
public List<Object[]> select(String... columns)
throws SQLException
{
StringBuilder sb = new StringBuilder();
for (String column : columns) {
if (sb.length() == 0) {
sb.append("SELECT ");
}
else {
sb.append(", ");
}
sb.append(column);
}
sb.append("\nFROM ").append(name);
String query = sb.toString();
List<Object[]> result = new ArrayList<Object[]>();
Statement st = conn.createStatement();
try {
ResultSet rs = st.executeQuery(query);
try {
int columnCount = rs.getMetaData().getColumnCount();
while (rs.next()) {
Object[] row = new Object[columnCount];
for (int i = 0; i < row.length; i++) {
row[i] = rs.getObject(i + 1);
}
result.add(row);
}
rowCount = result.size();
assert rowCount >= 0 : rowCount;
return result;
}
finally {
rs.close();
}
}
finally {
st.close();
}
}
public int[] aggregate(String... expressions)
throws SQLException
{
StringBuilder sb = new StringBuilder();
sb.append("SELECT COUNT(*)");
for (String expression : expressions) {
sb.append(", ").append(expression);
}
sb.append("\nFROM ").append(name);
String query = sb.toString();
Statement st = conn.createStatement();
try {
ResultSet rs = st.executeQuery(query);
try {
if (!rs.next()) {
throw new AssertionError();
}
int columnCount = rs.getMetaData().getColumnCount();
int[] result = new int[columnCount - 1];
for (int i = 0; i < result.length; i++) {
result[i] = rs.getInt(i + 2);
}
rowCount = rs.getLong(1);
assert rowCount >= 0 : rowCount;
return result;
}
finally {
rs.close();
}
}
finally {
st.close();
}
}
protected boolean optimize(int delta, long rowCount) {
if (delta > MAX_DELTA_TO_FORCE_OPTIMIZE) {
return true;
}
return delta != 0 && rowCount / delta <= 2;
}
protected String buildClear() {
return "DELETE FROM " + name;
}
protected String buildCreateTable(CharSequence columns) {
StringBuilder sb = new StringBuilder();
sb.append("CREATE TABLE ").append(name);
sb.append(" (\n").append(columns).append(")");
return sb.toString();
}
protected String buildCreateTransactionalTable(CharSequence columns) {
return buildCreateTable(columns);
}
protected String buildCreateTemporaryTable(CharSequence columns) {
StringBuilder sb = new StringBuilder();
sb.append("CREATE TEMPORARY TABLE ").append(name);
sb.append(" (\n").append(columns).append(")");
return sb.toString();
}
protected String buildPrimaryIndex(String... columns) {
StringBuilder sb = new StringBuilder();
sb.append("ALTER TABLE ");
sb.append(getName());
sb.append(" ADD PRIMARY KEY (");
for (int i = 0; i < columns.length; i++) {
if (i > 0) {
sb.append(", ");
}
sb.append(columns[i]);
}
sb.append(")");
return sb.toString();
}
protected String buildIndex(String... columns) {
StringBuilder sb = new StringBuilder();
sb.append("CREATE INDEX ").append(buildIndexName(columns));
sb.append(" ON ").append(name).append(" (");
for (int i = 0; i < columns.length; i++) {
if (i > 0) {
sb.append(", ");
}
sb.append(columns[i]);
}
sb.append(")");
return sb.toString();
}
protected String buildLongIndex(String... columns) {
return buildIndex(columns);
}
protected String buildDropIndex(String name) {
StringBuilder sb = new StringBuilder();
sb.append("DROP INDEX ").append(name);
return sb.toString();
}
/**
* Creates an index name based on the name of the columns and table that it's
* supposed to index.
*/
protected String buildIndexName(String... columns) {
StringBuffer sb = new StringBuffer(32);
sb.append(getName()).append("_").append(columns[0]);
for (int i = 1; i < columns.length; i++) {
sb.append("_").append(columns[i]);
}
sb.append("_idx");
return sb.toString();
}
protected String buildOptimize()
throws SQLException
{
// There is no default for this in SQL92.
return null;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((name == null) ? 0 : name.hashCode());
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (!(obj instanceof RdbmsTable)) {
return false;
}
final RdbmsTable other = (RdbmsTable)obj;
if (name == null) {
if (other.name != null) {
return false;
}
}
else if (!name.equals(other.name)) {
return false;
}
return true;
}
public void drop()
throws SQLException
{
execute("DROP TABLE " + name);
}
@Override
public String toString() {
return getName();
}
}