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/*
* Copyright (c) 2016, 2020, Oracle and/or its affiliates.
*
* This program is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License, version 2.0, as published by the
* Free Software Foundation.
*
* This program is also distributed with certain software (including but not
* limited to OpenSSL) that is licensed under separate terms, as designated in a
* particular file or component or in included license documentation. The
* authors of MySQL hereby grant you an additional permission to link the
* program and your derivative works with the separately licensed software that
* they have included with MySQL.
*
* Without limiting anything contained in the foregoing, this file, which is
* part of MySQL Connector/J, is also subject to the Universal FOSS Exception,
* version 1.0, a copy of which can be found at
* http://oss.oracle.com/licenses/universal-foss-exception.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License, version 2.0,
* for more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
package com.mysql.cj.protocol.a;
import com.mysql.cj.MysqlType;
import com.mysql.cj.protocol.ColumnDefinition;
import com.mysql.cj.protocol.ProtocolEntityFactory;
import com.mysql.cj.protocol.ProtocolEntityReader;
import com.mysql.cj.protocol.a.NativeConstants.IntegerDataType;
import com.mysql.cj.result.Field;
import com.mysql.cj.util.LazyString;
public class ColumnDefinitionReader implements ProtocolEntityReader {
private NativeProtocol protocol;
public ColumnDefinitionReader(NativeProtocol prot) {
this.protocol = prot;
}
@Override
public ColumnDefinition read(ProtocolEntityFactory sf) {
ColumnDefinitionFactory cdf = (ColumnDefinitionFactory) sf;
long columnCount = cdf.getColumnCount();
ColumnDefinition cdef = cdf.getColumnDefinitionFromCache();
if (cdef != null && !cdf.mergeColumnDefinitions()) {
for (int i = 0; i < columnCount; i++) {
this.protocol.skipPacket();
}
return cdef;
}
/* read the metadata from the server */
Field[] fields = null;
boolean checkEOF = !this.protocol.getServerSession().isEOFDeprecated();
// Read in the column information
fields = new Field[(int) columnCount];
for (int i = 0; i < columnCount; i++) {
NativePacketPayload fieldPacket = this.protocol.readMessage(null);
// next check is needed for SSPS
if (checkEOF && fieldPacket.isEOFPacket()) {
break;
}
fields[i] = unpackField(fieldPacket, this.protocol.getServerSession().getCharacterSetMetadata());
}
return cdf.createFromFields(fields);
}
/**
* Unpacks the Field information from the given packet.
*
* @param packet
* the packet containing the field information
* @param characterSetMetadata
* encoding of the metadata in the packet
*
* @return the unpacked field
*/
protected Field unpackField(NativePacketPayload packet, String characterSetMetadata) {
int offset, length;
length = (int) packet.readInteger(IntegerDataType.INT_LENENC);
packet.setPosition(packet.getPosition() + length); // skip database name
length = (int) packet.readInteger(IntegerDataType.INT_LENENC);
offset = packet.getPosition();
LazyString databaseName = new LazyString(packet.getByteBuffer(), offset, length, characterSetMetadata);
packet.setPosition(packet.getPosition() + length);
length = (int) packet.readInteger(IntegerDataType.INT_LENENC);
offset = packet.getPosition();
LazyString tableName = new LazyString(packet.getByteBuffer(), offset, length, characterSetMetadata);
packet.setPosition(packet.getPosition() + length);
length = (int) packet.readInteger(IntegerDataType.INT_LENENC);
offset = packet.getPosition();
LazyString originalTableName = new LazyString(packet.getByteBuffer(), offset, length, characterSetMetadata);
packet.setPosition(packet.getPosition() + length);
length = (int) packet.readInteger(IntegerDataType.INT_LENENC);
offset = packet.getPosition();
LazyString columnName = new LazyString(packet.getByteBuffer(), offset, length, characterSetMetadata);
packet.setPosition(packet.getPosition() + length);
length = (int) packet.readInteger(IntegerDataType.INT_LENENC);
offset = packet.getPosition();
LazyString originalColumnName = new LazyString(packet.getByteBuffer(), offset, length, characterSetMetadata);
packet.setPosition(packet.getPosition() + length);
packet.readInteger(IntegerDataType.INT1);
short collationIndex = (short) packet.readInteger(IntegerDataType.INT2);
long colLength = packet.readInteger(IntegerDataType.INT4);
int colType = (int) packet.readInteger(IntegerDataType.INT1);
short colFlag = (short) packet.readInteger(this.protocol.getServerSession().hasLongColumnInfo() ? IntegerDataType.INT2 : IntegerDataType.INT1);
int colDecimals = (int) packet.readInteger(IntegerDataType.INT1);
String encoding = this.protocol.getServerSession().getEncodingForIndex(collationIndex);
MysqlType mysqlType = NativeProtocol.findMysqlType(this.protocol.getPropertySet(), colType, colFlag, colLength, tableName, originalTableName,
collationIndex, encoding);
// Protocol returns precision and scale differently for some types. We need to align then to I_S.
switch (mysqlType) {
case TINYINT:
case TINYINT_UNSIGNED:
case SMALLINT:
case SMALLINT_UNSIGNED:
case MEDIUMINT:
case MEDIUMINT_UNSIGNED:
case INT:
case INT_UNSIGNED:
case BIGINT:
case BIGINT_UNSIGNED:
case BOOLEAN:
colLength = mysqlType.getPrecision().intValue();
break;
case DECIMAL:
colLength--;
if (colDecimals > 0) {
colLength--;
}
break;
case DECIMAL_UNSIGNED:
if (colDecimals > 0) {
colLength--;
}
break;
case FLOAT:
case FLOAT_UNSIGNED:
case DOUBLE:
case DOUBLE_UNSIGNED:
// According to SQL standard, NUMERIC_SCALE should be NULL for approximate numeric data types.
// DECIMAL_NOT_SPECIFIED=31 is the MySQL internal constant value used to indicate that NUMERIC_SCALE is not applicable.
// It's probably a mistake that it's exposed by protocol as a decimals and it should be replaced with 0.
if (colDecimals == 31) {
colDecimals = 0;
}
break;
default:
break;
}
return new Field(databaseName, tableName, originalTableName, columnName, originalColumnName, colLength, colType, colFlag, colDecimals, collationIndex,
encoding, mysqlType);
}
}
