net.grinder.statistics.ExpressionView Maven / Gradle / Ivy
// Copyright (C) 2000 - 2011 Philip Aston
// All rights reserved.
//
// This file is part of The Grinder software distribution. Refer to
// the file LICENSE which is part of The Grinder distribution for
// licensing details. The Grinder distribution is available on the
// Internet at http://grinder.sourceforge.net/
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
// FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
// COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
// OF THE POSSIBILITY OF SUCH DAMAGE.
package net.grinder.statistics;
/**
*
* Associate a statistic expression with display information.
*
*
*
* Statistic expressions are composed of statistic names (see
* {@link StatisticsIndexMap}) in a simple post-fix format using the symbols
* +, -, / and *,
* which have their usual meanings, in conjunction with simple statistic names
* or sub-expressions. Precedence can be controlled by grouping expressions in
* parentheses. For example, the error rate is
* (* (/ errors period) 1000) errors per second.
*
*
*
* Sample statistics, such as timedTests, must be introduced with
* one of sum, count, or variance,
* depending on the attribute of interest.
*
*
*
* For example, the statistic expression (/ (sum timedTests)
* (count timedTests))
* represents the mean test time in milliseconds.
*
* @author Philip Aston
*/
public final class ExpressionView {
private static int s_creationOrder;
private final String m_displayName;
private final String m_expressionString;
private final boolean m_showForCompositeStatistics;
private final int m_hashCode;
private final int m_creationOrder;
private final StatisticExpression m_expression;
ExpressionView(String displayName,
String expressionString,
StatisticExpression expression,
boolean showForCompositeStatistics) {
m_displayName = displayName;
m_expressionString = expressionString;
m_showForCompositeStatistics = showForCompositeStatistics;
m_expression = expression;
m_hashCode =
m_displayName.hashCode() ^
(expressionString != null ? m_expressionString.hashCode() : 0);
// Code outside this package can only obtain ExpressionViews through a
// StatisticExpressionFactory instance, and in turn this factory must be
// obtained from the singleton StatisticServices instance.
// StatisticsServicesImplementation creates the common statistics views in
// a static block, so we can rely on creation order to ensure that the
// standard views are ordered before script defined views.
synchronized (ExpressionView.class) {
m_creationOrder = s_creationOrder++;
}
}
/**
* Get the common display name.
*
* @return The display name.
*/
public String getDisplayName() {
return m_displayName;
}
/**
* Return the {@link StatisticExpression}.
*
* @return The {@link StatisticExpression}.
*/
public StatisticExpression getExpression() {
return m_expression;
}
/**
* Return the expression string.
*
* @return The string, or null if this view was built directly
* from a {@link StatisticExpression}.
*/
public String getExpressionString() {
return m_expressionString;
}
/**
* Return whether this view is relevant for totals of composite statistics.
* Many views (particularly those representing aggregate time, or averages)
* are ambiguous for composite statistics, so we don't show them.
*
* @return true => show this view for composite statistics.
*/
public boolean getShowForCompositeStatistics() {
return m_showForCompositeStatistics;
}
/**
* Value based equality.
*
* @param other An Object to compare.
* @return true => other is equal to this object.
*/
public boolean equals(Object other) {
if (other == this) {
return true;
}
if (other == null || other.getClass() != ExpressionView.class) {
return false;
}
final ExpressionView otherView = (ExpressionView)other;
return
m_hashCode == otherView.m_hashCode &&
m_displayName.equals(otherView.m_displayName) &&
// If either expression string is null, one of the views
// is not externalisable. If so, we only compare on the
// display names.
(m_expressionString == null ||
otherView.m_expressionString == null ||
m_expressionString.equals(otherView.m_expressionString));
}
/**
* Implement {@link Object#hashCode}.
*
* @return an int value
*/
public int hashCode() {
return m_hashCode;
}
/**
* Return a String representation of this
* ExpressionView.
*
* @return The String
*/
public String toString() {
final StringBuilder result = new StringBuilder(32);
result.append("ExpressionView(");
result.append(m_displayName);
if (m_expressionString != null) {
result.append(", ");
result.append(m_expressionString);
}
result.append(")");
return result.toString();
}
int getCreationOrder() {
return m_creationOrder;
}
}