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/*
* Licensed to the Apache Software Foundation (ASF) under one or more contributor license
* agreements. See the NOTICE file distributed with this work for additional information regarding
* copyright ownership. The ASF licenses this file to You 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 org.apache.geode;
// import org.apache.geode.distributed.DistributedSystem;
import org.apache.geode.internal.statistics.StatArchiveFormat;
import java.io.IOException;
import java.io.Reader;
/**
* Instances of this interface provide methods that create instances of {@link StatisticDescriptor}
* and {@link StatisticsType}. Every {@link StatisticsFactory} is also a type factory.
*
*
*
* A StatisticsTypeFactory can create a {@link StatisticDescriptor statistic} of three
* numeric types: int, long, and double. A statistic
* (StatisticDescriptor) can either be a gauge meaning that its value can
* increase and decrease or a counter meaning that its value is strictly increasing. Marking
* a statistic as a counter allows statistic display tools to properly display a statistics whose
* value "wraps around" (that is, exceeds its maximum value).
*
*
* The following code is an example of how to create a type using XML. In this example the type has
* two stats whose values always increase:
*
*
StatisticsTypeFactory f = ...;
StatisticsType t = f.createType(
"StatSampler",
"Stats on the statistic sampler.",
new StatisticDescriptor[] {
f.createIntCounter("sampleCount",
"Total number of samples taken by this sampler.",
"samples"),
f.createLongCounter("sampleTime",
"Total amount of time spent taking samples.",
"milliseconds"),
}
);
*
*
* The following is an example of how to create the same type using XML. The XML data:
*
*
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE statistics PUBLIC
"-//GemStone Systems, Inc.//GemFire Statistics Type//EN"
"http://www.gemstone.com/dtd/statisticsType.dtd">
<statistics>
<type name="StatSampler">
<description>Stats on the statistic sampler.</description>
<stat name="sampleCount" storage="int" counter="true">
<description>Total number of samples taken by this sampler.</description>
<unit>samples</unit>
</stat>
<stat name="sampleTime" storage="long" counter="true">
<description>Total amount of time spent taking samples.</description>
<unit>milliseconds</unit>
</stat>
</type>
</statistics>
*
*
* The code to create the type:
*
*
StatisticsTypeFactory f = ...;
Reader r = new InputStreamReader("fileContainingXmlData"));
StatisticsType type = f.createTypesFromXml(r)[0];
*
*
*
* @see Package introduction
*
*
* @since GemFire 3.0
*/
public interface StatisticsTypeFactory {
/**
* Creates and returns an int counter {@link StatisticDescriptor} with the given
* name, description, units, and with larger values
* indicating better performance.
*/
public StatisticDescriptor createIntCounter(String name, String description, String units);
/**
* Creates and returns a long counter {@link StatisticDescriptor} with the given
* name, description, units, and with larger values
* indicating better performance.
*/
public StatisticDescriptor createLongCounter(String name, String description, String units);
/**
* Creates and returns a double counter {@link StatisticDescriptor} with the given
* name, description, units, and with larger values
* indicating better performance.
*/
public StatisticDescriptor createDoubleCounter(String name, String description, String units);
/**
* Creates and returns an int gauge {@link StatisticDescriptor} with the given name,
* description, units, and with smaller values indicating better
* performance.
*/
public StatisticDescriptor createIntGauge(String name, String description, String units);
/**
* Creates and returns a long gauge {@link StatisticDescriptor} with the given name,
* description, units, and with smaller values indicating better
* performance.
*/
public StatisticDescriptor createLongGauge(String name, String description, String units);
/**
* Creates and returns a double gauge {@link StatisticDescriptor} with the given
* name, description, units, and with smaller values
* indicating better performance.
*/
public StatisticDescriptor createDoubleGauge(String name, String description, String units);
/**
* Creates and returns an int counter {@link StatisticDescriptor} with the given
* name, description, largerBetter, and units.
*/
public StatisticDescriptor createIntCounter(String name, String description, String units,
boolean largerBetter);
/**
* Creates and returns a long counter {@link StatisticDescriptor} with the given
* name, description, largerBetter, and units.
*/
public StatisticDescriptor createLongCounter(String name, String description, String units,
boolean largerBetter);
/**
* Creates and returns a double counter {@link StatisticDescriptor} with the given
* name, description, largerBetter, and units.
*/
public StatisticDescriptor createDoubleCounter(String name, String description, String units,
boolean largerBetter);
/**
* Creates and returns an int gauge {@link StatisticDescriptor} with the given name,
* description, largerBetter, and units.
*/
public StatisticDescriptor createIntGauge(String name, String description, String units,
boolean largerBetter);
/**
* Creates and returns a long gauge {@link StatisticDescriptor} with the given name,
* description, largerBetter, and units.
*/
public StatisticDescriptor createLongGauge(String name, String description, String units,
boolean largerBetter);
/**
* Creates and returns a double gauge {@link StatisticDescriptor} with the given
* name, description, largerBetter, and units.
*/
public StatisticDescriptor createDoubleGauge(String name, String description, String units,
boolean largerBetter);
/**
* The maximum number of descriptors a single statistics type can have.
*
* Current value is: 254
*/
public final int MAX_DESCRIPTORS_PER_TYPE = StatArchiveFormat.ILLEGAL_STAT_OFFSET - 1;
/**
* Creates or finds and returns a {@link StatisticsType} with the given name,
* description, and {@link StatisticDescriptor statistic descriptions}.
*
* @throws IllegalArgumentException if a type with the given name already exists and
* it differs from the given parameters.
*/
public StatisticsType createType(String name, String description, StatisticDescriptor[] stats);
/**
* Finds and returns an already created {@link StatisticsType} with the given name.
* Returns null if the type does not exist.
*/
public StatisticsType findType(String name);
/**
* Creates one or more {@link StatisticsType} from the contents of the given reader.
* The created types can be found by calling {@link #findType}.
*
* @param reader The source of the XML data which must comply with the
* statisticsType.dtd.
*
* @throws IllegalArgumentException if a type defined in the reader already exists
* @throws IOException Something went wrong while reading from reader
*/
public StatisticsType[] createTypesFromXml(Reader reader) throws IOException;
}