rrd
Class Rrd.FetchData

java.lang.Object
  |
  +--rrd.Rrd.FetchData

Enclosing class:

Rrd

public class Rrd.FetchData

extends java.lang.Object

Inner class to hold information returned by Rrd.fetch(). Logically, this information represents one simple table. Here is the example:

 timestamp     temperature1    temperature2
 ==========================================
 1000000000        36.2           66.9
 1000005000        39.3           69.2
 1000010000        40.0           68.3
 ..........        ....           ....
 1001000000        39.6           66.7
 ==========================================
 

To read this data use the following methods:

• getRowCount() to find the number of rows
• getColCount() to find the number of data columns
• getColName() to find the name of the i-th data column (zero based)
• getTimestamp(i) to find the timestamp of the i-th row (zero based)
• getValue(i, j) to find the value of the j-th data column on the i-th row

Example:

 String cmd = "fetch temperatures.rrd AVERAGE --start 1000000000 --end 1000086400";
 rrd.Rrd.FetchData data = Rrd.getInstance().fetch(cmd);
 int rows = data.getRowCount(), cols = data.getColCount();
 for(int i = 0; i < rows; i++) {
     System.out.print(i + ": t=" + data.getTimestamp(i) + " ");
     for(int j = 0; j < cols; j++) {
         System.out.print(data.getColName(j) + "=" + data.getValue(i, j) + " ");
     }
     System.out.println();
 }
 

Method Summary

int	getColCount() Returns number of columns (data sources) generated by Rrd.fetch() method.
java.lang.String	getColName(int col) Returns column (data source) name for the given column number
int	getRowCount() Returns number of rows generated by Rrd.fetch() method.
long	getTimestamp(int row) Returns timestamp of the given row.
double	getValue(int row, int col) Returns data source value from RRD database.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getTimestamp

public long getTimestamp(int row)

Returns timestamp of the given row.

Parameters:

row - Zero-based row number

Returns:

timestamp of the given row

getValue

public double getValue(int row,
                       int col)

Returns data source value from RRD database.

Parameters:

row - Zero-based row number.

col - Zero based data column number.

Returns:

value from the RRD database for the given row and column.

getColName

public java.lang.String getColName(int col)

Returns column (data source) name for the given column number

Parameters:

col - Zero-based column number.

Returns:

Column (data source) name

getColCount

public int getColCount()

Returns number of columns (data sources) generated by Rrd.fetch() method.

Returns:

Number of columns

getRowCount

public int getRowCount()

Returns number of rows generated by Rrd.fetch() method.

Returns:

Number of rows