/**
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package com.bigdata.btree;
import java.io.PrintWriter;
import java.util.Map;
/**
* Basic stats that are available for all index types and whose collection does
* not require visitation of the index pages.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
*/
public class BaseIndexStats {
/** The type of index. */
public IndexTypeEnum indexType;
/**
* The name associated with the index -or- <code>null</code> if the index is
* not named.
*/
public String name;
/**
* The current branching factor for the index.
*
* TODO GIST: [m] is BTree specific. The [addressBits] concept is the
* parallel for the HTree. This field should probably be moved into the
* concrete instances of the {@link PageStats} class.
*/
public int m;
/** The #of entries in the index. */
public long ntuples;
/** The height (aka depth) of the index */
public int height;
/** The #of nodes visited. */
public long nnodes;
/** The #of leaves visited. */
public long nleaves;
/**
* Zero-arg constructor does NOT initialize the fields.
*/
public BaseIndexStats() {
}
/**
* Initializes the fields for the specified index.
*/
public BaseIndexStats(final ICheckpointProtocol ndx) {
if (ndx == null)
throw new IllegalArgumentException();
final ICheckpoint checkpoint = ndx.getCheckpoint();
final IndexMetadata metadata = ndx.getIndexMetadata();
this.indexType = checkpoint.getIndexType();
this.name = metadata.getName();
switch (indexType) {
case BTree:
this.m = metadata.getBranchingFactor();
break;
case HTree:
m = ((HTreeIndexMetadata) metadata).getAddressBits();
break;
case Stream:
m = 0; // N/A
break;
default:
throw new AssertionError("Unknown indexType=" + indexType);
}
/*
* Note: The "height" of the HTree must be computed dynamically since
* the HTree is not a balanced tree. It will be reported as ZERO (0)
* using this logic.
*/
this.height = checkpoint.getHeight();
this.ntuples = checkpoint.getEntryCount();
this.nnodes = checkpoint.getNodeCount();
this.nleaves = checkpoint.getLeafCount();
}
/**
* Return the header row for a table.
*
* @return The header row.
*/
public String getHeaderRow() {
final StringBuilder sb = new StringBuilder();
sb.append("name");
sb.append('\t');
sb.append("indexType");
sb.append('\t');
sb.append("m");
sb.append('\t');
sb.append("height");
sb.append('\t');
sb.append("nnodes");
sb.append('\t');
sb.append("nleaves");
sb.append('\t');
sb.append("nentries");
return sb.toString();
}
/**
* Return a row of data for an index as aggregated by this {@link PageStats}
* object.
*
* @see #getHeaderRow()
*/
public String getDataRow() {
final BaseIndexStats stats = this;
final StringBuilder sb = new StringBuilder();
sb.append(name);
sb.append('\t');
sb.append(indexType);
sb.append('\t');
sb.append(stats.m);
sb.append('\t');
sb.append(stats.height);
sb.append('\t');
sb.append(stats.nnodes);
sb.append('\t');
sb.append(stats.nleaves);
sb.append('\t');
sb.append(stats.ntuples);
return sb.toString();
}
/**
* Helper method may be used to write out a tab-delimited table of the
* statistics.
*
* @param out
* Where to write the statistics.
*/
static public void writeOn(final PrintWriter out,
final Map<String, BaseIndexStats> statsMap) {
/*
* Write out the header.
*/
boolean first = true;
for (Map.Entry<String, BaseIndexStats> e : statsMap.entrySet()) {
final String name = e.getKey();
final BaseIndexStats stats = e.getValue();
if (stats == null) {
/*
* Something for which we did not extract the PageStats.
*/
out.println("name: " + name + " :: no statistics?");
continue;
}
if (first) {
out.println(stats.getHeaderRow());
first = false;
}
/*
* Write out the stats for this index.
*/
out.println(stats.getDataRow());
}
}
}