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<H1 CLASS="western">rrdFile module</H1>
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<HR>
<P>The <A HREF="../../src/lib/rrdFile.js">rrdFile Javascript
module</A> implements a set of classes that can be used to extract
information from <A HREF="http://oss.oetiker.ch/rrdtool/">RRD
archives</A> loaded as binary file objects.</P>
<HR>
</TD>
</TR>
</TABLE>
<H2 CLASS="heading-2-western">Overview</H2>
<P>The main class in this module is <A HREF="#RRDFile">RRDFile</A>.
It interprets the given the binary file object and provides methods
to decode the <A HREF="http://oss.oetiker.ch/rrdtool/">RRD</A>
information.</P>
<H2 CLASS="heading-2-western"><A NAME="RRDFile"></A>Class RRDFile</H2>
<P>This is the main class of the package. It is also the only class
the user ever needs to explicitly instantiate.</P>
<P>The RRDFile constructor has a single argument:</P>
<UL>
<LI><P>A binary file object.</P>
<P>Any object implementing an interface providing the following
methods can be used:</P>
<UL>
<LI><P>getByteAt(idx) - Return a 8 bit unsigned integer at offset
idx.</P>
<LI><P>getLongAt(idx) - Return a 32 bit unsigned integer at offset
idx.</P>
<LI><P>getDoubleAt(idx) - Return a double float at offset idx.</P>
<LI><P>getFastDoubleAt(idx) - Similar to getDoubleAt but with less
precision.</P>
<LI><P>getCStringAt(idx,maxsize) - Return a string of at most
maxsize characters that was 0-terminated in the source.</P>
</UL>
<P>The <A HREF="binaryXHR_js.html">binaryXHR module</A>, provided
with this package, provides the class <A HREF="binaryXHR_js.html#BinaryFile">BinaryFile</A>
that implements this interface.</P>
</UL>
<P>If the binary file is not a proper <A HREF="http://oss.oetiker.ch/rrdtool/">RRD
file</A>, an <A HREF="#InvalidRRD">InvalidRRD</A> exception will be
thrown.</P>
<P>This class also implements the following methods:</P>
<DIV ALIGN=RIGHT>
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<THEAD>
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<TH WIDTH=20%>
<P ALIGN=LEFT>Method</P>
</TH>
<TH WIDTH=80%>
<P ALIGN=LEFT>Description</P>
</TH>
</TR>
</THEAD>
<TBODY>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getMinStep()</P>
</TD>
<TD WIDTH=80%>
<P>Return the base <A HREF="http://oss.oetiker.ch/rrdtool/doc/rrdcreate.en.html#I__step__s_step__default__300_seconds_">interval
in seconds</A> that was used to feed the RRD file.</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getLastUpdate()</P>
</TD>
<TD WIDTH=80%>
<P>Return the timestamp of the <A HREF="http://oss.oetiker.ch/rrdtool/doc/rrdlastupdate.en.html">last
update</A>.</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getNrDSs()</P>
</TD>
<TD WIDTH=80%>
<P>Return the number of <A HREF="http://oss.oetiker.ch/rrdtool/doc/rrdcreate.en.html#IDS_ds_name_DST_dst_arguments">Data
Sources</A> present in the RRD file.
</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getDSNames()</P>
</TD>
<TD WIDTH=80%>
<P>Return the names of the <A HREF="http://oss.oetiker.ch/rrdtool/doc/rrdcreate.en.html#IDS_ds_name_DST_dst_arguments">Data
Sources</A> present in the RRD file.
</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getDS(id)</P>
</TD>
<TD WIDTH=80%>
<P>If id is a number, return an object of type <A HREF="#RRDDS">RRDDS</A> holding
the information about the id-th <A HREF="http://oss.oetiker.ch/rrdtool/doc/rrdcreate.en.html#IDS_ds_name_DST_dst_arguments">Data
Source</A>.</P>
<P>If id is a string, return an object of type <A HREF="#RRDDS">RRDDS</A> holding
the information about the <A HREF="http://oss.oetiker.ch/rrdtool/doc/rrdcreate.en.html#IDS_ds_name_DST_dst_arguments">Data
Source</A> with the requested name.</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getNrRRAs()</P>
</TD>
<TD WIDTH=80%>
<P>Return the number of <A HREF="http://oss.oetiker.ch/rrdtool/doc/rrdcreate.en.html#IRRA_CF_cf_arguments">Round
Robin Archives</A> present in the RRD file.</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getRRAInfo(n)</P>
</TD>
<TD WIDTH=80%>
<P>Return an object of type <A HREF="#RRDRRAInfo">RRDRRAInfo</A>
holding the information about the n-th <A HREF="http://oss.oetiker.ch/rrdtool/doc/rrdcreate.en.html#IRRA_CF_cf_arguments">Round
Robin Archive</A>.</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getRRA(n)</P>
</TD>
<TD WIDTH=80%>
<P>Return an object of type <A HREF="#RRDRRA">RRDRRA</A> that
can be used to access the values stored in the n-th <A HREF="http://oss.oetiker.ch/rrdtool/doc/rrdcreate.en.html#IRRA_CF_cf_arguments">Round
Robin Archive</A>.</P>
</TD>
</TR>
</TBODY>
</TABLE>
</DIV>
<H2 CLASS="heading-2-western"><A NAME="RRDDS"></A>Class RRDDS</H2>
<P>This class implements the methods needed to access the information
about a <A HREF="http://oss.oetiker.ch/rrdtool/doc/rrdcreate.en.html#IDS_ds_name_DST_dst_arguments">RRD
Data Source</A>.</P>
<DIV ALIGN=RIGHT>
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<COL WIDTH=51*>
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<THEAD>
<TR VALIGN=TOP>
<TH WIDTH=20%>
<P ALIGN=LEFT>Method</P>
</TH>
<TH WIDTH=80%>
<P ALIGN=LEFT>Description</P>
</TH>
</TR>
</THEAD>
<TBODY>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getIdx()</P>
</TD>
<TD WIDTH=80%>
<P>Return which DS it is in the RRD file.</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getName()</P>
</TD>
<TD WIDTH=80%>
<P>Return the name of the data source.</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getType()</P>
</TD>
<TD WIDTH=80%>
<P>Return the <A HREF="http://oss.oetiker.ch/rrdtool/doc/rrdcreate.en.html#IDS_ds_name_DST_dst_arguments">type</A>
of the data source.</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getMin()</P>
</TD>
<TD ROWSPAN=2 WIDTH=80%>
<P>Return the minimum and maximum value the data source can
contain.
</P>
<P>If either is not defined, <I>undefined</I> is returned.</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getMax()</P>
</TD>
</TR>
</TBODY>
</TABLE>
</DIV>
<H2 CLASS="heading-2-western"><A NAME="RRDRRAInfo"></A>Class
RRDRRAInfo</H2>
<P>This class implements the methods needed to access the information
about a <A HREF="http://oss.oetiker.ch/rrdtool/doc/rrdcreate.en.html#IRRA_CF_cf_arguments">Round
Robin Archive</A>.</P>
<DIV ALIGN=RIGHT>
<TABLE WIDTH=90% BORDER=1 CELLPADDING=2 CELLSPACING=3>
<COL WIDTH=52*>
<COL WIDTH=204*>
<THEAD>
<TR VALIGN=TOP>
<TH WIDTH=20%>
<P ALIGN=LEFT>Method</P>
</TH>
<TH WIDTH=80%>
<P ALIGN=LEFT>Description</P>
</TH>
</TR>
</THEAD>
<TBODY>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getIdx()</P>
</TD>
<TD WIDTH=80%>
<P>Return which RRA it is in the RRD file.</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getNrRows()</P>
</TD>
<TD WIDTH=80%>
<P>Return the number of rows in the RRA.</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getStep()</P>
</TD>
<TD WIDTH=80%>
<P>Return the number of seconds between rows.</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getCFName()</P>
</TD>
<TD WIDTH=80%>
<P>Return the <A HREF="http://oss.oetiker.ch/rrdtool/doc/rrdcreate.en.html#IRRA_CF_cf_arguments">Consolidation
Function</A> used by the RRA.</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getPdpPerRow()</P>
</TD>
<TD WIDTH=80%>
<P>Return number of slots used for consolidation.</P>
</TD>
</TR>
</TBODY>
</TABLE>
</DIV>
<H2 CLASS="heading-2-western"><A NAME="RRDRRA"></A>Class RRDRRA</H2>
<P>This class implements the methods needed to access the content of
a <A HREF="http://oss.oetiker.ch/rrdtool/doc/rrdcreate.en.html#IRRA_CF_cf_arguments">Round
Robin Archive</A>.</P>
<DIV ALIGN=RIGHT>
<TABLE WIDTH=90% BORDER=1 CELLPADDING=2 CELLSPACING=3>
<COL WIDTH=52*>
<COL WIDTH=204*>
<THEAD>
<TR VALIGN=TOP>
<TH WIDTH=20%>
<P ALIGN=LEFT>Method</P>
</TH>
<TH WIDTH=80%>
<P ALIGN=LEFT>Description</P>
</TH>
</TR>
</THEAD>
<TBODY>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getIdx()</P>
</TD>
<TD WIDTH=80%>
<P>Return which RRA it is in the RRD file.</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getCFName()</P>
</TD>
<TD WIDTH=80%>
<P>Return the <A HREF="http://oss.oetiker.ch/rrdtool/doc/rrdcreate.en.html#IRRA_CF_cf_arguments">Consolidation
Function</A> used by the RRA.</P>
<P>The current implementation only supports
AVERAGE,MAXIMUM,MINIMUM and LAST.<BR>Access to elements of any
other CF is currently undefined.
</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getNrRows()</P>
</TD>
<TD WIDTH=80%>
<P>Return the number of rows in the RRA.</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getNrDSs()</P>
</TD>
<TD WIDTH=80%>
<P>Return the number of <A HREF="http://oss.oetiker.ch/rrdtool/doc/rrdcreate.en.html#IDS_ds_name_DST_dst_arguments">Data
Sources</A> present in the RRA.</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getStep()</P>
</TD>
<TD WIDTH=80%>
<P>Return the number of seconds between rows.</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getEl(r,d)</P>
</TD>
<TD WIDTH=80%>
<P>Return the value for the d-th DS in the r-th row.</P>
</TD>
</TR>
<TR VALIGN=TOP>
<TD WIDTH=20%>
<P>getElFast(row,ds)</P>
</TD>
<TD WIDTH=80%>
<P>Return the low-precision value for the d-th DS in the r-th
row.</P>
</TD>
</TR>
</TBODY>
</TABLE>
</DIV>
<H2 CLASS="heading-2-western"><A NAME="InvalidRRD"></A>Exception
class InvalidRRD</H2>
<P>This is a helper exception class that can be thrown while
interpreting the binary file object.</P>
<P><BR><BR>
</P>
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<TR>
<TD>
<HR>
<P>This module is part of the <A HREF="index.html">javascriptRRD
package</A> hosted at <A HREF="http://javascriptrrd.sourceforge.net/">http://javascriptrrd.sourceforge.net</A>.
<BR>It is licensed under the <A HREF="http://www.opensource.org/licenses/mit-license.php">MIT
license</A>.
</P>
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