org.jrobin.core.FetchData Maven / Gradle / Ivy
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/*******************************************************************************
* Copyright (c) 2001-2005 Sasa Markovic and Ciaran Treanor.
* Copyright (c) 2011 The OpenNMS Group, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*******************************************************************************/
package org.jrobin.core;
import org.jrobin.data.Aggregates;
import org.jrobin.data.DataProcessor;
import java.io.ByteArrayOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
/**
* Class used to represent data fetched from the RRD.
* Object of this class is created when the method
* {@link FetchRequest#fetchData() fetchData()} is
* called on a {@link FetchRequest FetchRequest} object.
*
* Data returned from the RRD is, simply, just one big table filled with
* timestamps and corresponding datasource values.
* Use {@link #getRowCount() getRowCount()} method to count the number
* of returned timestamps (table rows).
*
* The first table column is filled with timestamps. Time intervals
* between consecutive timestamps are guaranteed to be equal. Use
* {@link #getTimestamps() getTimestamps()} method to get an array of
* timestamps returned.
*
* Remaining columns are filled with datasource values for the whole timestamp range,
* on a column-per-datasource basis. Use {@link #getColumnCount() getColumnCount()} to find
* the number of datasources and {@link #getValues(int) getValues(i)} method to obtain
* all values for the i-th datasource. Returned datasource values correspond to
* the values returned with {@link #getTimestamps() getTimestamps()} method.
*/
public class FetchData implements ConsolFuns {
// anything fuuny will do
private static final String RPN_SOURCE_NAME = "WHERE THE SPEECHLES UNITE IN A SILENT ACCORD";
private FetchRequest request;
private String[] dsNames;
private long[] timestamps;
private double[][] values;
private Archive matchingArchive;
private long arcStep;
private long arcEndTime;
FetchData(Archive matchingArchive, FetchRequest request) throws IOException {
this.matchingArchive = matchingArchive;
this.arcStep = matchingArchive.getArcStep();
this.arcEndTime = matchingArchive.getEndTime();
this.dsNames = request.getFilter();
if (this.dsNames == null) {
this.dsNames = matchingArchive.getParentDb().getDsNames();
}
this.request = request;
}
void setTimestamps(long[] timestamps) {
this.timestamps = timestamps;
}
void setValues(double[][] values) {
this.values = values;
}
/**
* Returns the number of rows fetched from the corresponding RRD.
* Each row represents datasource values for the specific timestamp.
*
* @return Number of rows.
*/
public int getRowCount() {
return timestamps.length;
}
/**
* Returns the number of columns fetched from the corresponding RRD.
* This number is always equal to the number of datasources defined
* in the RRD. Each column represents values of a single datasource.
*
* @return Number of columns (datasources).
*/
public int getColumnCount() {
return dsNames.length;
}
/**
* Returns an array of timestamps covering the whole range specified in the
* {@link FetchRequest FetchReguest} object.
*
* @return Array of equidistant timestamps.
*/
public long[] getTimestamps() {
return timestamps;
}
/**
* Returns the step with which this data was fetched.
*
* @return Step as long.
*/
public long getStep() {
return timestamps[1] - timestamps[0];
}
/**
* Returns all archived values for a single datasource.
* Returned values correspond to timestamps
* returned with {@link #getTimestamps() getTimestamps()} method.
*
* @param dsIndex Datasource index.
* @return Array of single datasource values.
*/
public double[] getValues(int dsIndex) {
return values[dsIndex];
}
/**
* Returns all archived values for all datasources.
* Returned values correspond to timestamps
* returned with {@link #getTimestamps() getTimestamps()} method.
*
* @return Two-dimensional aray of all datasource values.
*/
public double[][] getValues() {
return values;
}
/**
* Returns all archived values for a single datasource.
* Returned values correspond to timestamps
* returned with {@link #getTimestamps() getTimestamps()} method.
*
* @param dsName Datasource name.
* @return Array of single datasource values.
* @throws RrdException Thrown if no matching datasource name is found.
*/
public double[] getValues(String dsName) throws RrdException {
for (int dsIndex = 0; dsIndex < getColumnCount(); dsIndex++) {
if (dsName.equals(dsNames[dsIndex])) {
return getValues(dsIndex);
}
}
throw new RrdException("Datasource [" + dsName + "] not found");
}
/**
* Returns a set of values created by applying RPN expression to the fetched data.
* For example, if you have two datasources named x and y
* in this FetchData and you want to calculate values for (x+y)/2 use something like:
*
* getRpnValues("x,y,+,2,/");
*
* @param rpnExpression RRDTool-like RPN expression
* @return Calculated values
* @throws RrdException Thrown if invalid RPN expression is supplied
*/
public double[] getRpnValues(String rpnExpression) throws RrdException {
DataProcessor dataProcessor = createDataProcessor(rpnExpression);
return dataProcessor.getValues(RPN_SOURCE_NAME);
}
/**
* Returns {@link FetchRequest FetchRequest} object used to create this FetchData object.
*
* @return Fetch request object.
*/
public FetchRequest getRequest() {
return request;
}
/**
* Returns the first timestamp in this FetchData object.
*
* @return The smallest timestamp.
*/
public long getFirstTimestamp() {
return timestamps[0];
}
/**
* Returns the last timestamp in this FecthData object.
*
* @return The biggest timestamp.
*/
public long getLastTimestamp() {
return timestamps[timestamps.length - 1];
}
/**
* Returns Archive object which is determined to be the best match for the
* timestamps specified in the fetch request. All datasource values are obtained
* from round robin archives belonging to this archive.
*
* @return Matching archive.
*/
public Archive getMatchingArchive() {
return matchingArchive;
}
/**
* Returns array of datasource names found in the corresponding RRD. If the request
* was filtered (data was fetched only for selected datasources), only datasources selected
* for fetching are returned.
*
* @return Array of datasource names.
*/
public String[] getDsNames() {
return dsNames;
}
/**
* Retrieve the table index number of a datasource by name. Names are case sensitive.
*
* @param dsName Name of the datasource for which to find the index.
* @return Index number of the datasources in the value table.
*/
public int getDsIndex(String dsName) {
// Let's assume the table of dsNames is always small, so it is not necessary to use a hashmap for lookups
for (int i = 0; i < dsNames.length; i++) {
if (dsNames[i].equals(dsName)) {
return i;
}
}
return -1; // Datasource not found !
}
/**
* Dumps the content of the whole FetchData object. Useful for debugging.
*
* @return String containing the contents of this object, for debugging.
*/
public String dump() {
StringBuffer buffer = new StringBuffer("");
for (int row = 0; row < getRowCount(); row++) {
buffer.append(timestamps[row]);
buffer.append(": ");
for (int dsIndex = 0; dsIndex < getColumnCount(); dsIndex++) {
buffer.append(Util.formatDouble(values[dsIndex][row], true));
buffer.append(" ");
}
buffer.append("\n");
}
return buffer.toString();
}
/**
* Returns string representing fetched data in a RRDTool-like form.
*
* @return Fetched data as a string in a rrdfetch-like output form.
*/
public String toString() {
// print header row
StringBuffer buff = new StringBuffer();
buff.append(padWithBlanks("", 10));
buff.append(" ");
for (String dsName : dsNames) {
buff.append(padWithBlanks(dsName, 18));
}
buff.append("\n \n");
for (int i = 0; i < timestamps.length; i++) {
buff.append(padWithBlanks("" + timestamps[i], 10));
buff.append(":");
for (int j = 0; j < dsNames.length; j++) {
double value = values[j][i];
String valueStr = Double.isNaN(value) ? "nan" : Util.formatDouble(value);
buff.append(padWithBlanks(valueStr, 18));
}
buff.append("\n");
}
return buff.toString();
}
private static String padWithBlanks(String input, int width) {
StringBuffer buff = new StringBuffer("");
int diff = width - input.length();
while (diff-- > 0) {
buff.append(' ');
}
buff.append(input);
return buff.toString();
}
/**
* Returns single aggregated value from the fetched data for a single datasource.
*
* @param dsName Datasource name
* @param consolFun Consolidation function to be applied to fetched datasource values.
* Valid consolidation functions are "MIN", "MAX", "LAST", "FIRST", "AVERAGE" and "TOTAL"
* (these string constants are conveniently defined in the {@link ConsolFuns} class)
* @return MIN, MAX, LAST, FIRST, AVERAGE or TOTAL value calculated from the fetched data
* for the given datasource name
* @throws RrdException Thrown if the given datasource name cannot be found in fetched data.
*/
public double getAggregate(String dsName, String consolFun) throws RrdException {
DataProcessor dp = createDataProcessor(null);
return dp.getAggregate(dsName, consolFun);
}
/**
* Returns aggregated value from the fetched data for a single datasource.
* Before applying aggregation functions, specified RPN expression is applied to fetched data.
* For example, if you have a gauge datasource named 'foots' but you want to find the maximum
* fetched value in meters use something like:
*
* getAggregate("foots", "MAX", "foots,0.3048,*");
*
* @param dsName Datasource name
* @param consolFun Consolidation function (MIN, MAX, LAST, FIRST, AVERAGE or TOTAL)
* @param rpnExpression RRDTool-like RPN expression
* @return Aggregated value
* @throws RrdException Thrown if the given datasource name cannot be found in fetched data, or if
* invalid RPN expression is supplied
* @throws IOException Thrown in case of I/O error (unlikely to happen)
* @deprecated This method is preserved just for backward compatibility.
*/
public double getAggregate(String dsName, String consolFun, String rpnExpression)
throws RrdException, IOException {
// for backward compatibility
rpnExpression = rpnExpression.replaceAll("value", dsName);
return getRpnAggregate(rpnExpression, consolFun);
}
/**
* Returns aggregated value for a set of values calculated by applying an RPN expression to the
* fetched data. For example, if you have two datasources named x and y
* in this FetchData and you want to calculate MAX value of (x+y)/2 use something like:
*
* getRpnAggregate("x,y,+,2,/", "MAX");
*
* @param rpnExpression RRDTool-like RPN expression
* @param consolFun Consolidation function (MIN, MAX, LAST, FIRST, AVERAGE or TOTAL)
* @return Aggregated value
* @throws RrdException Thrown if invalid RPN expression is supplied
*/
public double getRpnAggregate(String rpnExpression, String consolFun) throws RrdException {
DataProcessor dataProcessor = createDataProcessor(rpnExpression);
return dataProcessor.getAggregate(RPN_SOURCE_NAME, consolFun);
}
/**
* Returns all aggregated values (MIN, MAX, LAST, FIRST, AVERAGE or TOTAL) calculated from the fetched data
* for a single datasource.
*
* @param dsName Datasource name.
* @return Simple object containing all aggregated values.
* @throws RrdException Thrown if the given datasource name cannot be found in the fetched data.
*/
public Aggregates getAggregates(String dsName) throws RrdException {
DataProcessor dataProcessor = createDataProcessor(null);
return dataProcessor.getAggregates(dsName);
}
/**
* Returns all aggregated values for a set of values calculated by applying an RPN expression to the
* fetched data. For example, if you have two datasources named x and y
* in this FetchData and you want to calculate MIN, MAX, LAST, FIRST, AVERAGE and TOTAL value
* of (x+y)/2 use something like:
*
* getRpnAggregates("x,y,+,2,/");
*
* @param rpnExpression RRDTool-like RPN expression
* @return Object containing all aggregated values
* @throws RrdException Thrown if invalid RPN expression is supplied
* @throws IOException Thrown in case of I/O error
*/
public Aggregates getRpnAggregates(String rpnExpression) throws RrdException, IOException {
DataProcessor dataProcessor = createDataProcessor(rpnExpression);
return dataProcessor.getAggregates(RPN_SOURCE_NAME);
}
/**
* Used by ISPs which charge for bandwidth utilization on a "95th percentile" basis.
*
* The 95th percentile is the highest source value left when the top 5% of a numerically sorted set
* of source data is discarded. It is used as a measure of the peak value used when one discounts
* a fair amount for transitory spikes. This makes it markedly different from the average.
*
* Read more about this topic at:
* Rednet or
* Bytemark.
*
* @param dsName Datasource name
* @return 95th percentile of fetched source values
* @throws RrdException Thrown if invalid source name is supplied
*/
public double get95Percentile(String dsName) throws RrdException {
DataProcessor dataProcessor = createDataProcessor(null);
return dataProcessor.get95Percentile(dsName);
}
/**
* Same as {@link #get95Percentile(String)}, but for a set of values calculated with the given
* RPN expression.
*
* @param rpnExpression RRDTool-like RPN expression
* @return 95-percentile
* @throws RrdException Thrown if invalid RPN expression is supplied
*/
public double getRpn95Percentile(String rpnExpression) throws RrdException {
DataProcessor dataProcessor = createDataProcessor(rpnExpression);
return dataProcessor.get95Percentile(RPN_SOURCE_NAME);
}
/**
* Dumps fetch data to output stream in XML format.
*
* @param outputStream Output stream to dump fetch data to
* @throws IOException Thrown in case of I/O error
*/
public void exportXml(OutputStream outputStream) throws IOException {
XmlWriter writer = new XmlWriter(outputStream);
writer.startTag("fetch_data");
writer.startTag("request");
writer.writeTag("file", request.getParentDb().getPath());
writer.writeComment(Util.getDate(request.getFetchStart()));
writer.writeTag("start", request.getFetchStart());
writer.writeComment(Util.getDate(request.getFetchEnd()));
writer.writeTag("end", request.getFetchEnd());
writer.writeTag("resolution", request.getResolution());
writer.writeTag("cf", request.getConsolFun());
writer.closeTag(); // request
writer.startTag("datasources");
for (String dsName : dsNames) {
writer.writeTag("name", dsName);
}
writer.closeTag(); // datasources
writer.startTag("data");
for (int i = 0; i < timestamps.length; i++) {
writer.startTag("row");
writer.writeComment(Util.getDate(timestamps[i]));
writer.writeTag("timestamp", timestamps[i]);
writer.startTag("values");
for (int j = 0; j < dsNames.length; j++) {
writer.writeTag("v", values[j][i]);
}
writer.closeTag(); // values
writer.closeTag(); // row
}
writer.closeTag(); // data
writer.closeTag(); // fetch_data
writer.flush();
}
/**
* Dumps fetch data to file in XML format.
*
* @param filepath Path to destination file
* @throws IOException Thrown in case of I/O error
*/
public void exportXml(String filepath) throws IOException {
OutputStream outputStream = null;
try {
outputStream = new FileOutputStream(filepath);
exportXml(outputStream);
}
finally {
if (outputStream != null) {
outputStream.close();
}
}
}
/**
* Dumps fetch data in XML format.
*
* @return String containing XML formatted fetch data
* @throws IOException Thrown in case of I/O error
*/
public String exportXml() throws IOException {
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
exportXml(outputStream);
return outputStream.toString();
}
/**
* Returns the step of the corresponding RRA archive
*
* @return Archive step in seconds
*/
public long getArcStep() {
return arcStep;
}
/**
* Returns the timestamp of the last populated slot in the corresponding RRA archive
*
* @return Timestamp in seconds
*/
public long getArcEndTime() {
return arcEndTime;
}
private DataProcessor createDataProcessor(String rpnExpression) throws RrdException {
DataProcessor dataProcessor = new DataProcessor(request.getFetchStart(), request.getFetchEnd());
for (String dsName : dsNames) {
dataProcessor.addDatasource(dsName, this);
}
if (rpnExpression != null) {
dataProcessor.addDatasource(RPN_SOURCE_NAME, rpnExpression);
try {
dataProcessor.processData();
}
catch (IOException ioe) {
// highly unlikely, since all datasources have already calculated values
throw new RuntimeException("Impossible error: " + ioe);
}
}
return dataProcessor;
}
}