io.aeron.command.CounterMessageFlyweight Maven / Gradle / Ivy
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/*
* Copyright 2014-2023 Real Logic Limited.
*
* 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
*
* https://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.command;
import io.aeron.exceptions.ControlProtocolException;
import org.agrona.DirectBuffer;
import org.agrona.MutableDirectBuffer;
import static io.aeron.ErrorCode.MALFORMED_COMMAND;
import static org.agrona.BitUtil.*;
/**
* Message to denote a new counter.
*
* Note: Layout should be SBE 2.0 compliant so that the label length is aligned.
*
* @see ControlProtocolEvents
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Client ID |
* | |
* +---------------------------------------------------------------+
* | Correlation ID |
* | |
* +---------------------------------------------------------------+
* | Counter Type ID |
* +---------------------------------------------------------------+
* | Key Length |
* +---------------------------------------------------------------+
* | Key Buffer ...
* ... |
* +---------------------------------------------------------------+
* | Label Length |
* +---------------------------------------------------------------+
* | Label (ASCII) ...
* ... |
* +---------------------------------------------------------------+
*
*/
public class CounterMessageFlyweight extends CorrelatedMessageFlyweight
{
private static final int COUNTER_TYPE_ID_FIELD_OFFSET = CORRELATION_ID_FIELD_OFFSET + SIZE_OF_LONG;
private static final int KEY_LENGTH_OFFSET = COUNTER_TYPE_ID_FIELD_OFFSET + SIZE_OF_INT;
static final int KEY_BUFFER_OFFSET = KEY_LENGTH_OFFSET + SIZE_OF_INT;
private static final int MINIMUM_LENGTH = KEY_BUFFER_OFFSET + SIZE_OF_INT;
/**
* Wrap the buffer at a given offset for updates.
*
* @param buffer to wrap.
* @param offset at which the message begins.
* @return this for a fluent API.
*/
public CounterMessageFlyweight wrap(final MutableDirectBuffer buffer, final int offset)
{
super.wrap(buffer, offset);
return this;
}
/**
* Get type id field.
*
* @return type id field.
*/
public int typeId()
{
return buffer.getInt(offset + COUNTER_TYPE_ID_FIELD_OFFSET);
}
/**
* Set counter type id field.
*
* @param typeId field value.
* @return this for a fluent API.
*/
public CounterMessageFlyweight typeId(final int typeId)
{
buffer.putInt(offset + COUNTER_TYPE_ID_FIELD_OFFSET, typeId);
return this;
}
/**
* Relative offset of the key buffer.
*
* @return relative offset of the key buffer.
*/
public int keyBufferOffset()
{
return KEY_BUFFER_OFFSET;
}
/**
* Length of the key buffer in bytes.
*
* @return length of key buffer in bytes.
*/
public int keyBufferLength()
{
return buffer.getInt(offset + KEY_LENGTH_OFFSET);
}
/**
* Fill the key buffer.
*
* @param keyBuffer containing the optional key for the counter.
* @param keyOffset within the keyBuffer at which the key begins.
* @param keyLength of the key in the keyBuffer.
* @return this for a fluent API.
*/
public CounterMessageFlyweight keyBuffer(final DirectBuffer keyBuffer, final int keyOffset, final int keyLength)
{
buffer.putInt(offset + KEY_LENGTH_OFFSET, keyLength);
if (null != keyBuffer && keyLength > 0)
{
buffer.putBytes(offset + KEY_BUFFER_OFFSET, keyBuffer, keyOffset, keyLength);
}
return this;
}
/**
* Relative offset of label buffer.
*
* @return relative offset of label buffer.
*/
public int labelBufferOffset()
{
return labelLengthOffset() + SIZE_OF_INT;
}
/**
* Length of label buffer in bytes.
*
* @return length of label buffer in bytes.
*/
public int labelBufferLength()
{
return buffer.getInt(offset + labelLengthOffset());
}
/**
* Fill the label buffer.
*
* @param labelBuffer containing the mandatory label for the counter.
* @param labelOffset within the labelBuffer at which the label begins.
* @param labelLength of the label in the labelBuffer.
* @return this for a fluent API.
*/
public CounterMessageFlyweight labelBuffer(
final DirectBuffer labelBuffer, final int labelOffset, final int labelLength)
{
final int labelLengthOffset = labelLengthOffset();
buffer.putInt(offset + labelLengthOffset, labelLength);
if (null != labelBuffer && labelLength > 0)
{
buffer.putBytes(offset + labelLengthOffset + SIZE_OF_INT, labelBuffer, labelOffset, labelLength);
}
return this;
}
/**
* Fill the label.
*
* @param label for the counter.
* @return this for a fluent API.
*/
public CounterMessageFlyweight label(final String label)
{
buffer.putStringAscii(offset + labelLengthOffset(), label);
return this;
}
/**
* Get the length of the current message.
*
* NB: must be called after the data is written in order to be accurate.
*
* @return the length of the current message
*/
public int length()
{
final int labelOffset = labelLengthOffset();
return labelOffset + SIZE_OF_INT + labelBufferLength();
}
/**
* Validate buffer length is long enough for message.
*
* @param msgTypeId type of message.
* @param length of message in bytes to validate.
*/
public void validateLength(final int msgTypeId, final int length)
{
if (length < MINIMUM_LENGTH)
{
throw new ControlProtocolException(
MALFORMED_COMMAND, "command=" + msgTypeId + " too short: length=" + length);
}
final int labelOffset = labelLengthOffset();
if ((length - labelOffset) < SIZE_OF_INT)
{
throw new ControlProtocolException(
MALFORMED_COMMAND, "command=" + msgTypeId + " too short for key: length=" + length);
}
final int encodedLength = length();
if (length < encodedLength)
{
throw new ControlProtocolException(
MALFORMED_COMMAND,
"command=" + msgTypeId + " too short for label: length=" + length + " encodedLength=" + encodedLength);
}
}
/**
* Compute the length of the command message given key and label length.
*
* @param keyLength to be appended.
* @param labelLength to be appended.
* @return the length of the command message given key and label length.
*/
public static int computeLength(final int keyLength, final int labelLength)
{
return MINIMUM_LENGTH + align(keyLength, SIZE_OF_INT) + SIZE_OF_INT + labelLength;
}
/**
* {@inheritDoc}
*/
public String toString()
{
return "CounterMessageFlyweight{" +
"clientId=" + clientId() +
", correlationId=" + correlationId() +
", typeId=" + typeId() +
", keyBufferOffset=" + keyBufferOffset() +
", keyBufferLength=" + keyBufferLength() +
", labelLengthOffset=" + labelLengthOffset() +
", labelBufferOffset=" + labelBufferOffset() +
", labelBufferLength=" + labelBufferLength() +
", length=" + length() +
"}";
}
private int labelLengthOffset()
{
return KEY_BUFFER_OFFSET + align(keyBufferLength(), SIZE_OF_INT);
}
}