mysqlio.java

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     *
     * @return a result set
     *
     * @throws SQLException if a database access error occurs
     */
    protected ResultSet getResultSet(Statement callingStatement,
        long columnCount, int maxRows, int resultSetType,
        int resultSetConcurrency, boolean streamResults, String catalog,
        boolean isBinaryEncoded, boolean unpackFieldInfo)
        throws SQLException {
        Buffer packet; // The packet from the server
        Field[] fields = null;

        if (unpackFieldInfo) {
            fields = new Field[(int) columnCount];
        }

        // Read in the column information
        for (int i = 0; i < columnCount; i++) {
            Buffer fieldPacket = null;

            if (this.useNewIo) {
                // allocations of NIO buffers are _very_, _very_
                // slow...(this code used to run 10x slower than 
                // it does now) so it is actually much faster to re-use,
                // extract the bytes, and wrap it as a plain-old
                // byte array packet.
                packet = reuseAndReadPacket(this.reusablePacket);

                if (unpackFieldInfo) {
                    fieldPacket = new ByteArrayBuffer(packet.getByteBuffer());
                }
            } else {
                fieldPacket = readPacket();
            }

            if (unpackFieldInfo) {
                fields[i] = unpackField(fieldPacket, false);
            }
        }

        packet = reuseAndReadPacket(this.reusablePacket);

        RowData rowData = null;
       
        if (!streamResults) {
            rowData = readSingleRowSet(columnCount, maxRows,
                    resultSetConcurrency, isBinaryEncoded, fields);
        } else {
            rowData = new RowDataDynamic(this, (int) columnCount, fields,
                    isBinaryEncoded);
            this.streamingData = rowData;
        }

        ResultSet rs = buildResultSetWithRows(callingStatement, catalog, fields,
            rowData, resultSetType, resultSetConcurrency, isBinaryEncoded);
 
        return rs;
    }

    /**
     * Forcibly closes the underlying socket to MySQL.
     */
    protected final void forceClose() {
        try {
            if (this.mysqlInput != null) {
                this.mysqlInput.close();
            }
        } catch (IOException ioEx) {
            // we can't do anything constructive about this
            // Let the JVM clean it up later
            this.mysqlInput = null;
        }

        try {
            if (this.mysqlOutput != null) {
                this.mysqlOutput.close();
            }
        } catch (IOException ioEx) {
            // we can't do anything constructive about this
            // Let the JVM clean it up later
            this.mysqlOutput = null;
        }

        try {
            if (this.mysqlConnection != null) {
                this.mysqlConnection.close();
            }
        } catch (IOException ioEx) {
            // we can't do anything constructive about this
            // Let the JVM clean it up later
            this.mysqlConnection = null;
        }
    }

    /**
     * Read one packet from the MySQL server
     *
     * @return the packet from the server.
     *
     * @throws SQLException DOCUMENT ME!
     * @throws CommunicationsException DOCUMENT ME!
     */
    protected final Buffer readPacket() throws SQLException {
        try {
            if (!this.useNewIo) {
                int lengthRead = readFully(this.mysqlInput,
                        this.packetHeaderBuf, 0, 4);

                if (lengthRead < 4) {
                    forceClose();
                    throw new IOException(Messages.getString("MysqlIO.1")); //$NON-NLS-1$
                }

                int packetLength = (this.packetHeaderBuf[0] & 0xff) +
                    ((this.packetHeaderBuf[1] & 0xff) << 8) +
                    ((this.packetHeaderBuf[2] & 0xff) << 16);

                if (this.traceProtocol) {
                    StringBuffer traceMessageBuf = new StringBuffer();

                    traceMessageBuf.append(Messages.getString("MysqlIO.2")); //$NON-NLS-1$
                    traceMessageBuf.append(packetLength);
                    traceMessageBuf.append(Messages.getString("MysqlIO.3")); //$NON-NLS-1$
                    traceMessageBuf.append(StringUtils.dumpAsHex(
                            this.packetHeaderBuf, 4));

                    this.connection.getLog().logTrace(traceMessageBuf.toString());
                }

                byte multiPacketSeq = this.packetHeaderBuf[3];

                if (!this.packetSequenceReset) {
                    if (this.enablePacketDebug && this.checkPacketSequence) {
                        checkPacketSequencing(multiPacketSeq);
                    }
                } else {
                    this.packetSequenceReset = false;
                }

                this.readPacketSequence = multiPacketSeq;

                // Read data
                byte[] buffer = new byte[packetLength + 1];
                int numBytesRead = readFully(this.mysqlInput, buffer, 0,
                        packetLength);

                if (numBytesRead != packetLength) {
                    throw new IOException("Short read, expected " +
                        packetLength + " bytes, only read " + numBytesRead);
                }

                buffer[packetLength] = 0;

                Buffer packet = Buffer.allocateNew(buffer, this.useNewIo);
                packet.setBufLength(packetLength + 1);

                if (this.traceProtocol) {
                    StringBuffer traceMessageBuf = new StringBuffer();

                    traceMessageBuf.append(Messages.getString("MysqlIO.4")); //$NON-NLS-1$
                    traceMessageBuf.append(getPacketDumpToLog(packet,
                            packetLength));

                    this.connection.getLog().logTrace(traceMessageBuf.toString());
                }

                if (this.enablePacketDebug) {
                    enqueuePacketForDebugging(false, false, 0,
                        this.packetHeaderBuf, packet);
                }

                return packet;
            }

            return readViaChannel();
        } catch (IOException ioEx) {
            throw new CommunicationsException(this.connection,
                this.lastPacketSentTimeMs, ioEx);
        }
    }

    /**
     * Unpacks the Field information from the given packet. Understands pre 4.1
     * and post 4.1 server version field packet structures.
     *
     * @param packet the packet containing the field information
     * @param extractDefaultValues should default values be extracted?
     *
     * @return the unpacked field
     *
     * @throws SQLException DOCUMENT ME!
     */
    protected final Field unpackField(Buffer packet,
        boolean extractDefaultValues) throws SQLException {
        if (this.use41Extensions) {
            // we only store the position of the string and
            // materialize only if needed...
            if (this.has41NewNewProt) {
                // Not used yet, 5.0?
                int catalogNameStart = packet.getPosition() + 1;
                int catalogNameLength = packet.fastSkipLenString();
            }

            int databaseNameStart = packet.getPosition() + 1;
            int databaseNameLength = packet.fastSkipLenString();

            int tableNameStart = packet.getPosition() + 1;
            int tableNameLength = packet.fastSkipLenString();

            // orgTableName is never used so skip
            int originalTableNameStart = packet.getPosition() + 1;
            int originalTableNameLength = packet.fastSkipLenString();

            // we only store the position again...
            int nameStart = packet.getPosition() + 1;
            int nameLength = packet.fastSkipLenString();

            // orgColName is not required so skip...
            int originalColumnNameStart = packet.getPosition() + 1;
            int originalColumnNameLength = packet.fastSkipLenString();

            packet.readByte();

            short charSetNumber = (short) packet.readInt();

            int colLength = 0;

            if (this.has41NewNewProt) {
                // fixme
                colLength = (int) packet.readLong();
            } else {
                colLength = packet.readLongInt();
            }

            int colType = packet.readByte() & 0xff;

            short colFlag = 0;

            if (this.hasLongColumnInfo) {
                colFlag = (short) packet.readInt();
            } else {
                colFlag = (short) (packet.readByte() & 0xff);
            }

            int colDecimals = packet.readByte() & 0xff;

            int defaultValueStart = -1;
            int defaultValueLength = -1;

            if (extractDefaultValues) {
                defaultValueStart = packet.getPosition() + 1;
                defaultValueLength = packet.fastSkipLenString();
            }

            Field field = new Field(this.connection, packet.getByteBuffer(),
                    databaseNameStart, databaseNameLength, tableNameStart,
                    tableNameLength, originalTableNameStart,
                    originalTableNameLength, nameStart, nameLength,
                    originalColumnNameStart, originalColumnNameLength,
                    colLength, colType, colFlag, colDecimals,
                    defaultValueStart, defaultValueLength, charSetNumber);

            return field;
        }

        int tableNameStart = packet.getPosition() + 1;
        int tableNameLength = packet.fastSkipLenString();
        int nameStart = packet.getPosition() + 1;
        int nameLength = packet.fastSkipLenString();
        int colLength = packet.readnBytes();
        int colType = packet.readnBytes();
        packet.readByte(); // We know it's currently 2

        short colFlag = 0;

        if (this.hasLongColumnInfo) {
            colFlag = (short) (packet.readInt());
        } else {
            colFlag = (short) (packet.readByte() & 0xff);
        }

        int colDecimals = (packet.readByte() & 0xff);

        if (this.colDecimalNeedsBump) {
            colDecimals++;
        }

        Field field = new Field(this.connection, packet.getByteBuffer(),
                nameStart, nameLength, tableNameStart, tableNameLength,
                colLength, colType, colFlag, colDecimals);

        return field;
    }

    protected boolean isSetNeededForAutoCommitMode(boolean autoCommitFlag) {
        if (this.use41Extensions && this.connection.getElideSetAutoCommits()) {
            boolean autoCommitModeOnServer = ((this.serverStatus &
                SERVER_STATUS_AUTOCOMMIT) != 0);

            if (!autoCommitFlag) {
                // Just to be safe, check if a transaction is in progress on the server....
                // if so, then we must be in autoCommit == false
                // therefore return the opposite of transaction status
                boolean inTransactionOnServer = ((this.serverStatus &
                    SERVER_STATUS_IN_TRANS) != 0);

                return !inTransactionOnServer;
            }

            return !autoCommitModeOnServer;
        }

        return true;
    }

    /**
     * Re-authenticates as the given user and password
     *
     * @param userName DOCUMENT ME!
     * @param password DOCUMENT ME!
     * @param database DOCUMENT ME!
     *
     * @throws SQLException DOCUMENT ME!
     */
    protected void changeUser(String userName, String password, String database)
        throws SQLException {
        this.packetSequence = -1;

        int passwordLength = 16;
        int userLength = 0;

        if (userName != null) {
            userLength = userName.length();
        }

        int packLength = (userLength + passwordLength) + 7 + HEADER_LENGTH;

        if ((this.serverCapabilities & CLIENT_SECURE_CONNECTION) != 0) {
            Buffer changeUserPacket = Buffer.allocateNew(packLength + 1,
                    this.useNewIo);
            changeUserPacket.writeByte((byte) MysqlDefs.COM_CHANGE_USER);

            if (versionMeetsMinimum(4, 1, 1)) {
                secureAuth411(changeUserPacket, packLength, userName, password,
                    database, false);
            } else {
                secureAuth(changeUserPacket, packLength, userName, password,
                    database, false);
            }
        } else {
            // Passwords can be 16 chars long
            Buffer packet = Buffer.allocateNew(packLength, this.useNewIo);
            packet.writeByte((byte) MysqlDefs.COM_CHANGE_USER);

            // User/Password data
            packet.writeString(userName);

            if (this.protocolVersion > 9) {
                packet.writeString(Util.newCrypt(password, this.seed));
            } else {
                packet.writeString(Util.oldCrypt(password, this.seed));
            }

            if (((this.serverCapabilities & CLIENT_CONNECT_WITH_DB) != 0) &&
                    (database != null) && (database.length() > 0)) {