Java Code Examples for com.taobao.tddl.dbsync.binlog.LogBuffer#getUint32()

public ExecuteLoadQueryLogEvent(LogHeader header, LogBuffer buffer, FormatDescriptionLogEvent descriptionEvent)
                                                                                                               throws IOException{
    super(header, buffer, descriptionEvent);

    buffer.position(descriptionEvent.commonHeaderLen + ELQ_FILE_ID_OFFSET);

    fileId = buffer.getUint32(); // ELQ_FILE_ID_OFFSET
    fnPosStart = (int) buffer.getUint32(); // ELQ_FN_POS_START_OFFSET
    fnPosEnd = (int) buffer.getUint32(); // ELQ_FN_POS_END_OFFSET
    dupHandling = buffer.getInt8(); // ELQ_DUP_HANDLING_OFFSET

    final int len = query.length();
    if (fnPosStart > len || fnPosEnd > len || dupHandling > LOAD_DUP_REPLACE) {
        throw new IOException(String.format("Invalid ExecuteLoadQueryLogEvent: fn_pos_start=%d, "
                                            + "fn_pos_end=%d, dup_handling=%d", fnPosStart, fnPosEnd, dupHandling));
    }
}
 

public ExecuteLoadQueryLogEvent(LogHeader header, LogBuffer buffer, FormatDescriptionLogEvent descriptionEvent)
                                                                                                               throws IOException{
    super(header, buffer, descriptionEvent);

    buffer.position(descriptionEvent.commonHeaderLen + ELQ_FILE_ID_OFFSET);

    fileId = buffer.getUint32(); // ELQ_FILE_ID_OFFSET
    fnPosStart = (int) buffer.getUint32(); // ELQ_FN_POS_START_OFFSET
    fnPosEnd = (int) buffer.getUint32(); // ELQ_FN_POS_END_OFFSET
    dupHandling = buffer.getInt8(); // ELQ_DUP_HANDLING_OFFSET

    final int len = query.length();
    if (fnPosStart > len || fnPosEnd > len || dupHandling > LOAD_DUP_REPLACE) {
        throw new IOException(String.format("Invalid ExecuteLoadQueryLogEvent: fn_pos_start=%d, "
                                            + "fn_pos_end=%d, dup_handling=%d", fnPosStart, fnPosEnd, dupHandling));
    }
}
 

public CreateFileLogEvent(LogHeader header, LogBuffer buffer, FormatDescriptionLogEvent descriptionEvent){
    super(header, buffer, descriptionEvent);

    final int headerLen = descriptionEvent.commonHeaderLen;
    final int loadHeaderLen = descriptionEvent.postHeaderLen[LOAD_EVENT - 1];
    final int createFileHeaderLen = descriptionEvent.postHeaderLen[CREATE_FILE_EVENT - 1];

    copyLogEvent(buffer,
        ((header.type == LOAD_EVENT) ? (loadHeaderLen + headerLen) : (headerLen + loadHeaderLen + createFileHeaderLen)),
        descriptionEvent);

    if (descriptionEvent.binlogVersion != 1) {
        fileId = buffer.getUint32(headerLen + loadHeaderLen + CF_FILE_ID_OFFSET);
        /*
         * Note that it's ok to use get_data_size() below, because it is
         * computed with values we have already read from this event
         * (because we called copy_log_event()); we are not using slave's
         * format info to decode master's format, we are really using
         * master's format info. Anyway, both formats should be identical
         * (except the common_header_len) as these Load events are not
         * changed between 4.0 and 5.0 (as logging of LOAD DATA INFILE does
         * not use Load_log_event in 5.0).
         */
        blockLen = buffer.limit() - buffer.position();
        blockBuf = buffer.duplicate(blockLen);
    } else {
        initedFromOld = true;
    }
}
 

public AppendBlockLogEvent(LogHeader header, LogBuffer buffer, FormatDescriptionLogEvent descriptionEvent){
    super(header);

    final int commonHeaderLen = descriptionEvent.commonHeaderLen;
    final int postHeaderLen = descriptionEvent.postHeaderLen[header.type - 1];
    final int totalHeaderLen = commonHeaderLen + postHeaderLen;

    buffer.position(commonHeaderLen + AB_FILE_ID_OFFSET);
    fileId = buffer.getUint32();

    buffer.position(postHeaderLen);
    blockLen = buffer.limit() - totalHeaderLen;
    blockBuf = buffer.duplicate(blockLen);
}
 

public ExecuteLoadLogEvent(LogHeader header, LogBuffer buffer, FormatDescriptionLogEvent descriptionEvent){
    super(header);

    final int commonHeaderLen = descriptionEvent.commonHeaderLen;
    buffer.position(commonHeaderLen + EL_FILE_ID_OFFSET);
    fileId = buffer.getUint32(); // EL_FILE_ID_OFFSET
}
 

public DeleteFileLogEvent(LogHeader header, LogBuffer buffer, FormatDescriptionLogEvent descriptionEvent){
    super(header);

    final int commonHeaderLen = descriptionEvent.commonHeaderLen;
    buffer.position(commonHeaderLen + DF_FILE_ID_OFFSET);
    fileId = buffer.getUint32(); // DF_FILE_ID_OFFSET
}
 

public DeleteFileLogEvent(LogHeader header, LogBuffer buffer, FormatDescriptionLogEvent descriptionEvent){
    super(header);

    final int commonHeaderLen = descriptionEvent.commonHeaderLen;
    buffer.position(commonHeaderLen + DF_FILE_ID_OFFSET);
    fileId = buffer.getUint32(); // DF_FILE_ID_OFFSET
}
 

public CreateFileLogEvent(LogHeader header, LogBuffer buffer, FormatDescriptionLogEvent descriptionEvent){
    super(header, buffer, descriptionEvent);

    final int headerLen = descriptionEvent.commonHeaderLen;
    final int loadHeaderLen = descriptionEvent.postHeaderLen[LOAD_EVENT - 1];
    final int createFileHeaderLen = descriptionEvent.postHeaderLen[CREATE_FILE_EVENT - 1];

    copyLogEvent(buffer,
        ((header.type == LOAD_EVENT) ? (loadHeaderLen + headerLen) : (headerLen + loadHeaderLen + createFileHeaderLen)),
        descriptionEvent);

    if (descriptionEvent.binlogVersion != 1) {
        fileId = buffer.getUint32(headerLen + loadHeaderLen + CF_FILE_ID_OFFSET);
        /*
         * Note that it's ok to use get_data_size() below, because it is
         * computed with values we have already read from this event
         * (because we called copy_log_event()); we are not using slave's
         * format info to decode master's format, we are really using
         * master's format info. Anyway, both formats should be identical
         * (except the common_header_len) as these Load events are not
         * changed between 4.0 and 5.0 (as logging of LOAD DATA INFILE does
         * not use Load_log_event in 5.0).
         */
        blockLen = buffer.limit() - buffer.position();
        blockBuf = buffer.duplicate(blockLen);
    } else {
        initedFromOld = true;
    }
}
 

public ExecuteLoadLogEvent(LogHeader header, LogBuffer buffer, FormatDescriptionLogEvent descriptionEvent){
    super(header);

    final int commonHeaderLen = descriptionEvent.commonHeaderLen;
    buffer.position(commonHeaderLen + EL_FILE_ID_OFFSET);
    fileId = buffer.getUint32(); // EL_FILE_ID_OFFSET
}
 

public AppendBlockLogEvent(LogHeader header, LogBuffer buffer, FormatDescriptionLogEvent descriptionEvent){
    super(header);

    final int commonHeaderLen = descriptionEvent.commonHeaderLen;
    final int postHeaderLen = descriptionEvent.postHeaderLen[header.type - 1];
    final int totalHeaderLen = commonHeaderLen + postHeaderLen;

    buffer.position(commonHeaderLen + AB_FILE_ID_OFFSET);
    fileId = buffer.getUint32();

    buffer.position(postHeaderLen);
    blockLen = buffer.limit() - totalHeaderLen;
    blockBuf = buffer.duplicate(blockLen);
}
 

public RowsLogEvent(LogHeader header, LogBuffer buffer, FormatDescriptionLogEvent descriptionEvent, boolean partial){
    super(header);

    final int commonHeaderLen = descriptionEvent.commonHeaderLen;
    final int postHeaderLen = descriptionEvent.postHeaderLen[header.type - 1];
    int headerLen = 0;
    buffer.position(commonHeaderLen + RW_MAPID_OFFSET);
    if (postHeaderLen == 6) {
        /*
         * Master is of an intermediate source tree before 5.1.4. Id is 4
         * bytes
         */
        tableId = buffer.getUint32();
    } else {
        tableId = buffer.getUlong48(); // RW_FLAGS_OFFSET
    }
    flags = buffer.getUint16();

    if (postHeaderLen == FormatDescriptionLogEvent.ROWS_HEADER_LEN_V2) {
        headerLen = buffer.getUint16();
        headerLen -= 2;
        int start = buffer.position();
        int end = start + headerLen;
        for (int i = start; i < end;) {
            switch (buffer.getUint8(i++)) {
                case RW_V_EXTRAINFO_TAG:
                    // int infoLen = buffer.getUint8();
                    buffer.position(i + EXTRA_ROW_INFO_LEN_OFFSET);
                    int checkLen = buffer.getUint8(); // EXTRA_ROW_INFO_LEN_OFFSET
                    int val = checkLen - EXTRA_ROW_INFO_HDR_BYTES;
                    assert (buffer.getUint8() == val); // EXTRA_ROW_INFO_FORMAT_OFFSET
                    for (int j = 0; j < val; j++) {
                        assert (buffer.getUint8() == val); // EXTRA_ROW_INFO_HDR_BYTES
                                                           // + i
                    }
                    break;
                default:
                    i = end;
                    break;
            }
        }
    }

    buffer.position(commonHeaderLen + postHeaderLen + headerLen);
    columnLen = (int) buffer.getPackedLong();
    this.partial = partial;
    columns = buffer.getBitmap(columnLen);

    if (header.type == UPDATE_ROWS_EVENT_V1 || header.type == UPDATE_ROWS_EVENT
        || header.type == PARTIAL_UPDATE_ROWS_EVENT) {
        changeColumns = buffer.getBitmap(columnLen);
    } else {
        changeColumns = columns;
    }

    // XXX: Don't handle buffer in another thread.
    int dataSize = buffer.limit() - buffer.position();
    rowsBuf = buffer.duplicate(dataSize);
}
 

private void processCheckSum(LogBuffer buffer) {
    if (checksumAlg != LogEvent.BINLOG_CHECKSUM_ALG_OFF && checksumAlg != LogEvent.BINLOG_CHECKSUM_ALG_UNDEF) {
        crc = buffer.getUint32(eventLen - LogEvent.BINLOG_CHECKSUM_LEN);
    }
}
 

public LogHeader(LogBuffer buffer, FormatDescriptionLogEvent descriptionEvent){
    when = buffer.getUint32();
    type = buffer.getUint8(); // LogEvent.EVENT_TYPE_OFFSET;
    serverId = buffer.getUint32(); // LogEvent.SERVER_ID_OFFSET;
    eventLen = (int) buffer.getUint32(); // LogEvent.EVENT_LEN_OFFSET;

    if (descriptionEvent.binlogVersion == 1) {
        logPos = 0;
        flags = 0;
        return;
    }

    /* 4.0 or newer */
    logPos = buffer.getUint32(); // LogEvent.LOG_POS_OFFSET
    /*
     * If the log is 4.0 (so here it can only be a 4.0 relay log read by the
     * SQL thread or a 4.0 master binlog read by the I/O thread), log_pos is
     * the beginning of the event: we transform it into the end of the
     * event, which is more useful. But how do you know that the log is 4.0:
     * you know it if description_event is version 3 *and* you are not
     * reading a Format_desc (remember that mysqlbinlog starts by assuming
     * that 5.0 logs are in 4.0 format, until it finds a Format_desc).
     */
    if (descriptionEvent.binlogVersion == 3 && type < LogEvent.FORMAT_DESCRIPTION_EVENT && logPos != 0) {
        /*
         * If log_pos=0, don't change it. log_pos==0 is a marker to mean
         * "don't change rli->group_master_log_pos" (see
         * inc_group_relay_log_pos()). As it is unreal log_pos, adding the
         * event len's is nonsense. For example, a fake Rotate event should
         * not have its log_pos (which is 0) changed or it will modify
         * Exec_master_log_pos in SHOW SLAVE STATUS, displaying a nonsense
         * value of (a non-zero offset which does not exist in the master's
         * binlog, so which will cause problems if the user uses this value
         * in CHANGE MASTER).
         */
        logPos += eventLen; /* purecov: inspected */
    }

    flags = buffer.getUint16(); // LogEvent.FLAGS_OFFSET
    if ((type == LogEvent.FORMAT_DESCRIPTION_EVENT) || (type == LogEvent.ROTATE_EVENT)) {
        /*
         * These events always have a header which stops here (i.e. their
         * header is FROZEN).
         */
        /*
         * Initialization to zero of all other Log_event members as they're
         * not specified. Currently there are no such members; in the future
         * there will be an event UID (but Format_description and Rotate
         * don't need this UID, as they are not propagated through
         * --log-slave-updates (remember the UID is used to not play a query
         * twice when you have two masters which are slaves of a 3rd
         * master). Then we are done.
         */

        if (type == LogEvent.FORMAT_DESCRIPTION_EVENT) {
            int commonHeaderLen = buffer.getUint8(FormatDescriptionLogEvent.LOG_EVENT_MINIMAL_HEADER_LEN
                                                  + FormatDescriptionLogEvent.ST_COMMON_HEADER_LEN_OFFSET);
            buffer.position(commonHeaderLen + FormatDescriptionLogEvent.ST_SERVER_VER_OFFSET);
            String serverVersion = buffer.getFixString(FormatDescriptionLogEvent.ST_SERVER_VER_LEN); // ST_SERVER_VER_OFFSET
            int versionSplit[] = new int[] { 0, 0, 0 };
            FormatDescriptionLogEvent.doServerVersionSplit(serverVersion, versionSplit);
            checksumAlg = LogEvent.BINLOG_CHECKSUM_ALG_UNDEF;
            if (FormatDescriptionLogEvent.versionProduct(versionSplit) >= FormatDescriptionLogEvent.checksumVersionProduct) {
                buffer.position(eventLen - LogEvent.BINLOG_CHECKSUM_LEN - LogEvent.BINLOG_CHECKSUM_ALG_DESC_LEN);
                checksumAlg = buffer.getUint8();
            }

            processCheckSum(buffer);
        }
        return;
    }

    /*
     * CRC verification by SQL and Show-Binlog-Events master side. The
     * caller has to provide @description_event->checksum_alg to be the last
     * seen FD's (A) descriptor. If event is FD the descriptor is in it.
     * Notice, FD of the binlog can be only in one instance and therefore
     * Show-Binlog-Events executing master side thread needs just to know
     * the only FD's (A) value - whereas RL can contain more. In the RL
     * case, the alg is kept in FD_e (@description_event) which is reset to
     * the newer read-out event after its execution with possibly new alg
     * descriptor. Therefore in a typical sequence of RL: {FD_s^0, FD_m,
     * E_m^1} E_m^1 will be verified with (A) of FD_m. See legends
     * definition on MYSQL_BIN_LOG::relay_log_checksum_alg docs lines
     * (log.h). Notice, a pre-checksum FD version forces alg :=
     * BINLOG_CHECKSUM_ALG_UNDEF.
     */
    checksumAlg = descriptionEvent.getHeader().checksumAlg; // fetch
                                                            // checksum alg
    processCheckSum(buffer);
    /* otherwise, go on with reading the header from buf (nothing now) */
}
 

/**
 * @see mysql-5.1.60/sql/log_event.cc - Load_log_event::copy_log_event
 */
protected final void copyLogEvent(LogBuffer buffer, final int bodyOffset, FormatDescriptionLogEvent descriptionEvent) {
    /* this is the beginning of the post-header */
    buffer.position(descriptionEvent.commonHeaderLen + L_EXEC_TIME_OFFSET);

    execTime = buffer.getUint32(); // L_EXEC_TIME_OFFSET
    skipLines = (int) buffer.getUint32(); // L_SKIP_LINES_OFFSET
    final int tableNameLen = buffer.getUint8(); // L_TBL_LEN_OFFSET
    final int dbLen = buffer.getUint8(); // L_DB_LEN_OFFSET
    numFields = (int) buffer.getUint32(); // L_NUM_FIELDS_OFFSET

    buffer.position(bodyOffset);
    /*
     * Sql_ex.init() on success returns the pointer to the first byte after
     * the sql_ex structure, which is the start of field lengths array.
     */
    if (header.type != LOAD_EVENT /* use_new_format */) {
        /*
         * The code below assumes that buf will not disappear from under our
         * feet during the lifetime of the event. This assumption holds true
         * in the slave thread if the log is in new format, but is not the
         * case when we have old format because we will be reusing net
         * buffer to read the actual file before we write out the
         * Create_file event.
         */
        fieldTerm = buffer.getString();
        enclosed = buffer.getString();
        lineTerm = buffer.getString();
        lineStart = buffer.getString();
        escaped = buffer.getString();
        optFlags = buffer.getInt8();
        emptyFlags = 0;
    } else {
        fieldTerm = buffer.getFixString(1);
        enclosed = buffer.getFixString(1);
        lineTerm = buffer.getFixString(1);
        lineStart = buffer.getFixString(1);
        escaped = buffer.getFixString(1);
        optFlags = buffer.getUint8();
        emptyFlags = buffer.getUint8();

        if ((emptyFlags & FIELD_TERM_EMPTY) != 0) fieldTerm = null;
        if ((emptyFlags & ENCLOSED_EMPTY) != 0) enclosed = null;
        if ((emptyFlags & LINE_TERM_EMPTY) != 0) lineTerm = null;
        if ((emptyFlags & LINE_START_EMPTY) != 0) lineStart = null;
        if ((emptyFlags & ESCAPED_EMPTY) != 0) escaped = null;
    }

    final int fieldLenPos = buffer.position();
    buffer.forward(numFields);
    fields = new String[numFields];
    for (int i = 0; i < numFields; i++) {
        final int fieldLen = buffer.getUint8(fieldLenPos + i);
        fields[i] = buffer.getFixString(fieldLen + 1);
    }

    table = buffer.getFixString(tableNameLen + 1);
    db = buffer.getFixString(dbLen + 1);

    // null termination is accomplished by the caller
    final int from = buffer.position();
    final int end = from + buffer.limit();
    int found = from;
    for (; (found < end) && buffer.getInt8(found) != '\0'; found++)
        /* empty loop */;
    fname = buffer.getString(found);
    buffer.forward(1); // The + 1 is for \0 terminating fname
}
 

public UserVarLogEvent(LogHeader header, LogBuffer buffer, FormatDescriptionLogEvent descriptionEvent)
                                                                                                      throws IOException{
    super(header);

    /* The Post-Header is empty. The Variable Data part begins immediately. */
    buffer.position(descriptionEvent.commonHeaderLen + descriptionEvent.postHeaderLen[USER_VAR_EVENT - 1]);
    final int nameLen = (int) buffer.getUint32();
    name = buffer.getFixString(nameLen); // UV_NAME_LEN_SIZE
    isNull = (0 != buffer.getInt8());

    if (isNull) {
        type = STRING_RESULT;
        charsetNumber = 63; /* binary */
        value = null;
    } else {
        type = buffer.getInt8(); // UV_VAL_IS_NULL
        charsetNumber = (int) buffer.getUint32(); // buf + UV_VAL_TYPE_SIZE
        final int valueLen = (int) buffer.getUint32(); // buf +
                                                       // UV_CHARSET_NUMBER_SIZE
        final int limit = buffer.limit(); /* for restore */
        buffer.limit(buffer.position() + valueLen);

        /* @see User_var_log_event::print */
        switch (type) {
            case REAL_RESULT:
                value = Double.valueOf(buffer.getDouble64()); // float8get
                break;
            case INT_RESULT:
                if (valueLen == 8) value = Long.valueOf(buffer.getLong64()); // !uint8korr
                else if (valueLen == 4) value = Long.valueOf(buffer.getUint32());
                else throw new IOException("Error INT_RESULT length: " + valueLen);
                break;
            case DECIMAL_RESULT:
                final int precision = buffer.getInt8();
                final int scale = buffer.getInt8();
                value = buffer.getDecimal(precision, scale); // bin2decimal
                break;
            case STRING_RESULT:
                String charsetName = CharsetConversion.getJavaCharset(charsetNumber);
                value = buffer.getFixString(valueLen, charsetName);
                break;
            case ROW_RESULT:
                // this seems to be banned in MySQL altogether
                throw new IOException("ROW_RESULT is unsupported");
            default:
                value = null;
                break;
        }
        buffer.limit(limit);
    }
}
 

public RowsLogEvent(LogHeader header, LogBuffer buffer, FormatDescriptionLogEvent descriptionEvent, boolean partial){
    super(header);

    final int commonHeaderLen = descriptionEvent.commonHeaderLen;
    final int postHeaderLen = descriptionEvent.postHeaderLen[header.type - 1];
    int headerLen = 0;
    buffer.position(commonHeaderLen + RW_MAPID_OFFSET);
    if (postHeaderLen == 6) {
        /*
         * Master is of an intermediate source tree before 5.1.4. Id is 4
         * bytes
         */
        tableId = buffer.getUint32();
    } else {
        tableId = buffer.getUlong48(); // RW_FLAGS_OFFSET
    }
    flags = buffer.getUint16();

    if (postHeaderLen == FormatDescriptionLogEvent.ROWS_HEADER_LEN_V2) {
        headerLen = buffer.getUint16();
        headerLen -= 2;
        int start = buffer.position();
        int end = start + headerLen;
        for (int i = start; i < end;) {
            switch (buffer.getUint8(i++)) {
                case RW_V_EXTRAINFO_TAG:
                    // int infoLen = buffer.getUint8();
                    buffer.position(i + EXTRA_ROW_INFO_LEN_OFFSET);
                    int checkLen = buffer.getUint8(); // EXTRA_ROW_INFO_LEN_OFFSET
                    int val = checkLen - EXTRA_ROW_INFO_HDR_BYTES;
                    assert (buffer.getUint8() == val); // EXTRA_ROW_INFO_FORMAT_OFFSET
                    for (int j = 0; j < val; j++) {
                        assert (buffer.getUint8() == val); // EXTRA_ROW_INFO_HDR_BYTES
                                                           // + i
                    }
                    break;
                default:
                    i = end;
                    break;
            }
        }
    }

    buffer.position(commonHeaderLen + postHeaderLen + headerLen);
    columnLen = (int) buffer.getPackedLong();
    this.partial = partial;
    columns = buffer.getBitmap(columnLen);

    if (header.type == UPDATE_ROWS_EVENT_V1 || header.type == UPDATE_ROWS_EVENT
        || header.type == PARTIAL_UPDATE_ROWS_EVENT) {
        changeColumns = buffer.getBitmap(columnLen);
    } else {
        changeColumns = columns;
    }

    // XXX: Don't handle buffer in another thread.
    int dataSize = buffer.limit() - buffer.position();
    rowsBuf = buffer.duplicate(dataSize);
}
 

private void processCheckSum(LogBuffer buffer) {
    if (checksumAlg != LogEvent.BINLOG_CHECKSUM_ALG_OFF && checksumAlg != LogEvent.BINLOG_CHECKSUM_ALG_UNDEF) {
        crc = buffer.getUint32(eventLen - LogEvent.BINLOG_CHECKSUM_LEN);
    }
}
 

public LogHeader(LogBuffer buffer, FormatDescriptionLogEvent descriptionEvent){
    when = buffer.getUint32();
    type = buffer.getUint8(); // LogEvent.EVENT_TYPE_OFFSET;
    serverId = buffer.getUint32(); // LogEvent.SERVER_ID_OFFSET;
    eventLen = (int) buffer.getUint32(); // LogEvent.EVENT_LEN_OFFSET;

    if (descriptionEvent.binlogVersion == 1) {
        logPos = 0;
        flags = 0;
        return;
    }

    /* 4.0 or newer */
    logPos = buffer.getUint32(); // LogEvent.LOG_POS_OFFSET
    /*
     * If the log is 4.0 (so here it can only be a 4.0 relay log read by the
     * SQL thread or a 4.0 master binlog read by the I/O thread), log_pos is
     * the beginning of the event: we transform it into the end of the
     * event, which is more useful. But how do you know that the log is 4.0:
     * you know it if description_event is version 3 *and* you are not
     * reading a Format_desc (remember that mysqlbinlog starts by assuming
     * that 5.0 logs are in 4.0 format, until it finds a Format_desc).
     */
    if (descriptionEvent.binlogVersion == 3 && type < LogEvent.FORMAT_DESCRIPTION_EVENT && logPos != 0) {
        /*
         * If log_pos=0, don't change it. log_pos==0 is a marker to mean
         * "don't change rli->group_master_log_pos" (see
         * inc_group_relay_log_pos()). As it is unreal log_pos, adding the
         * event len's is nonsense. For example, a fake Rotate event should
         * not have its log_pos (which is 0) changed or it will modify
         * Exec_master_log_pos in SHOW SLAVE STATUS, displaying a nonsense
         * value of (a non-zero offset which does not exist in the master's
         * binlog, so which will cause problems if the user uses this value
         * in CHANGE MASTER).
         */
        logPos += eventLen; /* purecov: inspected */
    }

    flags = buffer.getUint16(); // LogEvent.FLAGS_OFFSET
    if ((type == LogEvent.FORMAT_DESCRIPTION_EVENT) || (type == LogEvent.ROTATE_EVENT)) {
        /*
         * These events always have a header which stops here (i.e. their
         * header is FROZEN).
         */
        /*
         * Initialization to zero of all other Log_event members as they're
         * not specified. Currently there are no such members; in the future
         * there will be an event UID (but Format_description and Rotate
         * don't need this UID, as they are not propagated through
         * --log-slave-updates (remember the UID is used to not play a query
         * twice when you have two masters which are slaves of a 3rd
         * master). Then we are done.
         */

        if (type == LogEvent.FORMAT_DESCRIPTION_EVENT) {
            int commonHeaderLen = buffer.getUint8(FormatDescriptionLogEvent.LOG_EVENT_MINIMAL_HEADER_LEN
                                                  + FormatDescriptionLogEvent.ST_COMMON_HEADER_LEN_OFFSET);
            buffer.position(commonHeaderLen + FormatDescriptionLogEvent.ST_SERVER_VER_OFFSET);
            String serverVersion = buffer.getFixString(FormatDescriptionLogEvent.ST_SERVER_VER_LEN); // ST_SERVER_VER_OFFSET
            int versionSplit[] = new int[] { 0, 0, 0 };
            FormatDescriptionLogEvent.doServerVersionSplit(serverVersion, versionSplit);
            checksumAlg = LogEvent.BINLOG_CHECKSUM_ALG_UNDEF;
            if (FormatDescriptionLogEvent.versionProduct(versionSplit) >= FormatDescriptionLogEvent.checksumVersionProduct) {
                buffer.position(eventLen - LogEvent.BINLOG_CHECKSUM_LEN - LogEvent.BINLOG_CHECKSUM_ALG_DESC_LEN);
                checksumAlg = buffer.getUint8();
            }

            processCheckSum(buffer);
        }
        return;
    }

    /*
     * CRC verification by SQL and Show-Binlog-Events master side. The
     * caller has to provide @description_event->checksum_alg to be the last
     * seen FD's (A) descriptor. If event is FD the descriptor is in it.
     * Notice, FD of the binlog can be only in one instance and therefore
     * Show-Binlog-Events executing master side thread needs just to know
     * the only FD's (A) value - whereas RL can contain more. In the RL
     * case, the alg is kept in FD_e (@description_event) which is reset to
     * the newer read-out event after its execution with possibly new alg
     * descriptor. Therefore in a typical sequence of RL: {FD_s^0, FD_m,
     * E_m^1} E_m^1 will be verified with (A) of FD_m. See legends
     * definition on MYSQL_BIN_LOG::relay_log_checksum_alg docs lines
     * (log.h). Notice, a pre-checksum FD version forces alg :=
     * BINLOG_CHECKSUM_ALG_UNDEF.
     */
    checksumAlg = descriptionEvent.getHeader().checksumAlg; // fetch
                                                            // checksum alg
    processCheckSum(buffer);
    /* otherwise, go on with reading the header from buf (nothing now) */
}
 

/**
 * @see mysql-5.1.60/sql/log_event.cc - Load_log_event::copy_log_event
 */
protected final void copyLogEvent(LogBuffer buffer, final int bodyOffset, FormatDescriptionLogEvent descriptionEvent) {
    /* this is the beginning of the post-header */
    buffer.position(descriptionEvent.commonHeaderLen + L_EXEC_TIME_OFFSET);

    execTime = buffer.getUint32(); // L_EXEC_TIME_OFFSET
    skipLines = (int) buffer.getUint32(); // L_SKIP_LINES_OFFSET
    final int tableNameLen = buffer.getUint8(); // L_TBL_LEN_OFFSET
    final int dbLen = buffer.getUint8(); // L_DB_LEN_OFFSET
    numFields = (int) buffer.getUint32(); // L_NUM_FIELDS_OFFSET

    buffer.position(bodyOffset);
    /*
     * Sql_ex.init() on success returns the pointer to the first byte after
     * the sql_ex structure, which is the start of field lengths array.
     */
    if (header.type != LOAD_EVENT /* use_new_format */) {
        /*
         * The code below assumes that buf will not disappear from under our
         * feet during the lifetime of the event. This assumption holds true
         * in the slave thread if the log is in new format, but is not the
         * case when we have old format because we will be reusing net
         * buffer to read the actual file before we write out the
         * Create_file event.
         */
        fieldTerm = buffer.getString();
        enclosed = buffer.getString();
        lineTerm = buffer.getString();
        lineStart = buffer.getString();
        escaped = buffer.getString();
        optFlags = buffer.getInt8();
        emptyFlags = 0;
    } else {
        fieldTerm = buffer.getFixString(1);
        enclosed = buffer.getFixString(1);
        lineTerm = buffer.getFixString(1);
        lineStart = buffer.getFixString(1);
        escaped = buffer.getFixString(1);
        optFlags = buffer.getUint8();
        emptyFlags = buffer.getUint8();

        if ((emptyFlags & FIELD_TERM_EMPTY) != 0) fieldTerm = null;
        if ((emptyFlags & ENCLOSED_EMPTY) != 0) enclosed = null;
        if ((emptyFlags & LINE_TERM_EMPTY) != 0) lineTerm = null;
        if ((emptyFlags & LINE_START_EMPTY) != 0) lineStart = null;
        if ((emptyFlags & ESCAPED_EMPTY) != 0) escaped = null;
    }

    final int fieldLenPos = buffer.position();
    buffer.forward(numFields);
    fields = new String[numFields];
    for (int i = 0; i < numFields; i++) {
        final int fieldLen = buffer.getUint8(fieldLenPos + i);
        fields[i] = buffer.getFixString(fieldLen + 1);
    }

    table = buffer.getFixString(tableNameLen + 1);
    db = buffer.getFixString(dbLen + 1);

    // null termination is accomplished by the caller
    final int from = buffer.position();
    final int end = from + buffer.limit();
    int found = from;
    for (; (found < end) && buffer.getInt8(found) != '\0'; found++)
        /* empty loop */;
    fname = buffer.getString(found);
    buffer.forward(1); // The + 1 is for \0 terminating fname
}
 

public UserVarLogEvent(LogHeader header, LogBuffer buffer, FormatDescriptionLogEvent descriptionEvent)
                                                                                                      throws IOException{
    super(header);

    /* The Post-Header is empty. The Variable Data part begins immediately. */
    buffer.position(descriptionEvent.commonHeaderLen + descriptionEvent.postHeaderLen[USER_VAR_EVENT - 1]);
    final int nameLen = (int) buffer.getUint32();
    name = buffer.getFixString(nameLen); // UV_NAME_LEN_SIZE
    isNull = (0 != buffer.getInt8());

    if (isNull) {
        type = STRING_RESULT;
        charsetNumber = 63; /* binary */
        value = null;
    } else {
        type = buffer.getInt8(); // UV_VAL_IS_NULL
        charsetNumber = (int) buffer.getUint32(); // buf + UV_VAL_TYPE_SIZE
        final int valueLen = (int) buffer.getUint32(); // buf +
                                                       // UV_CHARSET_NUMBER_SIZE
        final int limit = buffer.limit(); /* for restore */
        buffer.limit(buffer.position() + valueLen);

        /* @see User_var_log_event::print */
        switch (type) {
            case REAL_RESULT:
                value = Double.valueOf(buffer.getDouble64()); // float8get
                break;
            case INT_RESULT:
                if (valueLen == 8) value = Long.valueOf(buffer.getLong64()); // !uint8korr
                else if (valueLen == 4) value = Long.valueOf(buffer.getUint32());
                else throw new IOException("Error INT_RESULT length: " + valueLen);
                break;
            case DECIMAL_RESULT:
                final int precision = buffer.getInt8();
                final int scale = buffer.getInt8();
                value = buffer.getDecimal(precision, scale); // bin2decimal
                break;
            case STRING_RESULT:
                String charsetName = CharsetConversion.getJavaCharset(charsetNumber);
                value = buffer.getFixString(valueLen, charsetName);
                break;
            case ROW_RESULT:
                // this seems to be banned in MySQL altogether
                throw new IOException("ROW_RESULT is unsupported");
            default:
                value = null;
                break;
        }
        buffer.limit(limit);
    }
}