/*
* Copyright 2014-2017 Real Logic Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.aeron;
import org.agrona.DirectBuffer;
import org.agrona.concurrent.UnsafeBuffer;
import java.nio.ByteBuffer;
import static org.agrona.BitUtil.*;
/**
* Description of the command and control file used between driver and clients
*
* File Layout
* <pre>
* +----------------------------+
* | Aeron CnC Version |
* +----------------------------+
* | Meta Data |
* +----------------------------+
* | to-driver Buffer |
* +----------------------------+
* | to-clients Buffer |
* +----------------------------+
* | Counter Metadata Buffer |
* +----------------------------+
* | Counter Values Buffer |
* +----------------------------+
* | Error Log |
* +----------------------------+
* </pre>
*
* Meta Data Layout (CnC Version 6)
* <pre>
* +----------------------------+
* | to-driver buffer length |
* +----------------------------+
* | to-clients buffer length |
* +----------------------------+
* | metadata buffer length |
* +----------------------------+
* | values buffer length |
* +----------------------------+
* | Client Liveness Timeout |
* | |
* +----------------------------+
* | Error Log length |
* +----------------------------+
* </pre>
*/
public class CncFileDescriptor
{
public static final String CNC_FILE = "cnc.dat";
public static final int CNC_VERSION = 6;
public static final int CNC_VERSION_FIELD_OFFSET;
public static final int CNC_METADATA_OFFSET;
/* Meta Data Offsets (offsets within the meta data section) */
public static final int TO_DRIVER_BUFFER_LENGTH_FIELD_OFFSET;
public static final int TO_CLIENTS_BUFFER_LENGTH_FIELD_OFFSET;
public static final int COUNTERS_METADATA_BUFFER_LENGTH_FIELD_OFFSET;
public static final int COUNTERS_VALUES_BUFFER_LENGTH_FIELD_OFFSET;
public static final int CLIENT_LIVENESS_TIMEOUT_FIELD_OFFSET;
public static final int ERROR_LOG_BUFFER_LENGTH_FIELD_OFFSET;
static
{
CNC_VERSION_FIELD_OFFSET = 0;
CNC_METADATA_OFFSET = CNC_VERSION_FIELD_OFFSET + SIZE_OF_INT;
TO_DRIVER_BUFFER_LENGTH_FIELD_OFFSET = 0;
TO_CLIENTS_BUFFER_LENGTH_FIELD_OFFSET = TO_DRIVER_BUFFER_LENGTH_FIELD_OFFSET + SIZE_OF_INT;
COUNTERS_METADATA_BUFFER_LENGTH_FIELD_OFFSET = TO_CLIENTS_BUFFER_LENGTH_FIELD_OFFSET + SIZE_OF_INT;
COUNTERS_VALUES_BUFFER_LENGTH_FIELD_OFFSET = COUNTERS_METADATA_BUFFER_LENGTH_FIELD_OFFSET + SIZE_OF_INT;
CLIENT_LIVENESS_TIMEOUT_FIELD_OFFSET = COUNTERS_VALUES_BUFFER_LENGTH_FIELD_OFFSET + SIZE_OF_INT;
ERROR_LOG_BUFFER_LENGTH_FIELD_OFFSET = CLIENT_LIVENESS_TIMEOUT_FIELD_OFFSET + SIZE_OF_LONG;
}
public static final int META_DATA_LENGTH = ERROR_LOG_BUFFER_LENGTH_FIELD_OFFSET + SIZE_OF_INT;
public static final int END_OF_METADATA_OFFSET = align(SIZE_OF_INT + META_DATA_LENGTH, (CACHE_LINE_LENGTH * 2));
/**
* Compute the length of the cnc file and return it.
*
* @param totalLengthOfBuffers in bytes
* @return cnc file length in bytes
*/
public static int computeCncFileLength(final int totalLengthOfBuffers)
{
return END_OF_METADATA_OFFSET + totalLengthOfBuffers;
}
public static int cncVersionOffset(final int baseOffset)
{
return baseOffset + CNC_VERSION_FIELD_OFFSET;
}
public static int toDriverBufferLengthOffset(final int baseOffset)
{
return baseOffset + CNC_METADATA_OFFSET + TO_DRIVER_BUFFER_LENGTH_FIELD_OFFSET;
}
public static int toClientsBufferLengthOffset(final int baseOffset)
{
return baseOffset + CNC_METADATA_OFFSET + TO_CLIENTS_BUFFER_LENGTH_FIELD_OFFSET;
}
public static int countersMetaDataBufferLengthOffset(final int baseOffset)
{
return baseOffset + CNC_METADATA_OFFSET + COUNTERS_METADATA_BUFFER_LENGTH_FIELD_OFFSET;
}
public static int countersValuesBufferLengthOffset(final int baseOffset)
{
return baseOffset + CNC_METADATA_OFFSET + COUNTERS_VALUES_BUFFER_LENGTH_FIELD_OFFSET;
}
public static int clientLivenessTimeoutOffset(final int baseOffset)
{
return baseOffset + CNC_METADATA_OFFSET + CLIENT_LIVENESS_TIMEOUT_FIELD_OFFSET;
}
public static int errorLogBufferLengthOffset(final int baseOffset)
{
return baseOffset + CNC_METADATA_OFFSET + ERROR_LOG_BUFFER_LENGTH_FIELD_OFFSET;
}
public static void fillMetaData(
final UnsafeBuffer cncMetaDataBuffer,
final int toDriverBufferLength,
final int toClientsBufferLength,
final int counterMetaDataBufferLength,
final int counterValuesBufferLength,
final long clientLivenessTimeout,
final int errorLogBufferLength)
{
cncMetaDataBuffer.putInt(toDriverBufferLengthOffset(0), toDriverBufferLength);
cncMetaDataBuffer.putInt(toClientsBufferLengthOffset(0), toClientsBufferLength);
cncMetaDataBuffer.putInt(countersMetaDataBufferLengthOffset(0), counterMetaDataBufferLength);
cncMetaDataBuffer.putInt(countersValuesBufferLengthOffset(0), counterValuesBufferLength);
cncMetaDataBuffer.putLong(clientLivenessTimeoutOffset(0), clientLivenessTimeout);
cncMetaDataBuffer.putInt(errorLogBufferLengthOffset(0), errorLogBufferLength);
cncMetaDataBuffer.putIntVolatile(cncVersionOffset(0), CNC_VERSION);
}
public static UnsafeBuffer createMetaDataBuffer(final ByteBuffer buffer)
{
return new UnsafeBuffer(buffer, 0, SIZE_OF_INT + META_DATA_LENGTH);
}
public static UnsafeBuffer createToDriverBuffer(final ByteBuffer buffer, final DirectBuffer metaDataBuffer)
{
return new UnsafeBuffer(buffer, END_OF_METADATA_OFFSET, metaDataBuffer.getInt(toDriverBufferLengthOffset(0)));
}
public static UnsafeBuffer createToClientsBuffer(final ByteBuffer buffer, final DirectBuffer metaDataBuffer)
{
final int offset = END_OF_METADATA_OFFSET + metaDataBuffer.getInt(toDriverBufferLengthOffset(0));
return new UnsafeBuffer(buffer, offset, metaDataBuffer.getInt(toClientsBufferLengthOffset(0)));
}
public static UnsafeBuffer createCountersMetaDataBuffer(final ByteBuffer buffer, final DirectBuffer metaDataBuffer)
{
final int offset = END_OF_METADATA_OFFSET +
metaDataBuffer.getInt(toDriverBufferLengthOffset(0)) +
metaDataBuffer.getInt(toClientsBufferLengthOffset(0));
return new UnsafeBuffer(buffer, offset, metaDataBuffer.getInt(countersMetaDataBufferLengthOffset(0)));
}
public static UnsafeBuffer createCountersValuesBuffer(final ByteBuffer buffer, final DirectBuffer metaDataBuffer)
{
final int offset = END_OF_METADATA_OFFSET +
metaDataBuffer.getInt(toDriverBufferLengthOffset(0)) +
metaDataBuffer.getInt(toClientsBufferLengthOffset(0)) +
metaDataBuffer.getInt(countersMetaDataBufferLengthOffset(0));
return new UnsafeBuffer(buffer, offset, metaDataBuffer.getInt(countersValuesBufferLengthOffset(0)));
}
public static UnsafeBuffer createErrorLogBuffer(final ByteBuffer buffer, final DirectBuffer metaDataBuffer)
{
final int offset = END_OF_METADATA_OFFSET +
metaDataBuffer.getInt(toDriverBufferLengthOffset(0)) +
metaDataBuffer.getInt(toClientsBufferLengthOffset(0)) +
metaDataBuffer.getInt(countersMetaDataBufferLengthOffset(0)) +
metaDataBuffer.getInt(countersValuesBufferLengthOffset(0));
return new UnsafeBuffer(buffer, offset, metaDataBuffer.getInt(errorLogBufferLengthOffset(0)));
}
public static long clientLivenessTimeout(final DirectBuffer metaDataBuffer)
{
return metaDataBuffer.getLong(clientLivenessTimeoutOffset(0));
}
}