/*
* Copyright (c) 2008, Jan Stender, Bjoern Kolbeck, Mikael Hoegqvist,
* Felix Hupfeld, Zuse Institute Berlin
*
* Licensed under the BSD License, see LICENSE file for details.
*
*/
package de.mxro.thrd.babudb05.sandbox;
import java.io.File;
import java.util.Map.Entry;
import de.mxro.thrd.babudb05.api.database.ResultSet;
import de.mxro.thrd.babudb05.index.DefaultByteRangeComparator;
import de.mxro.thrd.babudb05.index.LSMTree;
import de.mxro.thrd.babudb05.index.writer.DiskIndexWriter;
public class LSMTreePerformanceTest {
public static void main(String[] args) throws Exception {
if (args.length != 4) {
System.out.println("usage: java " + LSMTreePerformanceTest.class.getCanonicalName()
+ " <db_file> <num_entries> <num_inserts> <num_lookups>");
System.exit(1);
}
final String path = args[0];
final int entriesPerBlock = 16;
final int minStrLen = 1;
final int maxStrLen = 8;
final char minChar = 48;
final char maxChar = 122;
final int size = Integer.parseInt(args[1]);
final int inserts = Integer.parseInt(args[2]);
final int lookups = Integer.parseInt(args[3]);
// TODO: make configurable
final int blockFileSize = 1024 * 1024 * 1024;
if (size != 0) {
// delete old index file
new File(path).delete();
System.out.println("creating new database with " + size + " random entries ...");
// write the map to a disk index
DiskIndexWriter index = new DiskIndexWriter(path, entriesPerBlock, false, blockFileSize);
index.writeIndex(new ResultSet<Object, Object>() {
private int count;
private String next = minChar + "";
@Override
public boolean hasNext() {
return count < size;
}
@Override
public Entry<Object, Object> next() {
count++;
next = createNextString(next, minStrLen, maxStrLen, minChar, maxChar);
return new Entry<Object, Object>() {
@Override
public Object getKey() {
return next.getBytes();
}
@Override
public Object getValue() {
return next.getBytes();
}
@Override
public Object setValue(Object value) {
throw new UnsupportedOperationException();
}
};
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
@Override
public void free() {
}
});
}
// read the LSM tree
LSMTree tree = new LSMTree(path, new DefaultByteRangeComparator(), false, 16, 1024 * 1024 * 512, true, -1);
System.out.println("inserting " + inserts + " random elements ...");
for (int i = 0; i < inserts; i++) {
byte[] entry = createRandomString(minChar, maxChar, minStrLen, maxStrLen).getBytes();
tree.insert(entry, entry);
}
// Iterator<Entry<ReusableBuffer, ReusableBuffer>> it =
// tree.prefixLookup(null);
// while (it.hasNext())
// System.out.println(new String(it.next().getKey().array()));
//
System.out.println("performing " + lookups + " random lookups ...");
// look up each element
int hits = 0;
long t0 = System.currentTimeMillis();
for (int i = 0; i < lookups; i++) {
byte[] key = createRandomString(minChar, maxChar, minStrLen, maxStrLen).getBytes();
byte[] result = tree.lookup(key);
if (result != null)
hits++;
if (i % 100000 == 0)
System.out.println(i);
}
long time = System.currentTimeMillis() - t0;
System.out.println(time + " ms");
System.out.println((long) lookups * 1000 / time + " lookups/s");
System.out.println("hits: " + hits + " / " + lookups);
}
private static String createNextString(String st, int minStrLen, int maxStrLen, char minChar, char maxChar) {
char[] chars = st.toCharArray();
for (;;) {
double rnd = Math.random();
if (rnd < .1f + .8f / chars.length && chars.length < maxStrLen) {
// append character
char[] chars2 = new char[chars.length + 1];
System.arraycopy(chars, 0, chars2, 0, chars.length);
chars2[chars2.length - 1] = createRandomChar(minChar, maxChar);
return new String(chars2);
} else if (rnd > .95f + .05f / chars.length && chars.length > minStrLen) {
int i = chars.length - 2;
for (; i >= 0; i--)
if (chars[i] < maxChar)
break;
if (i == -1)
continue;
// increment character and truncate
char[] chars2 = new char[i + 1];
System.arraycopy(chars, 0, chars2, 0, chars2.length);
chars2[chars2.length - 1]++;
return new String(chars2);
} else if (chars[chars.length - 1] < maxChar) {
// increment last character
chars[chars.length - 1]++;
return new String(chars);
}
}
}
private static String createRandomString(char minChar, char maxChar, int minLength, int maxLength) {
char[] chars = new char[(int) (Math.random() * (maxLength + 1)) + minLength];
for (int i = 0; i < chars.length; i++)
chars[i] = createRandomChar(minChar, maxChar);
return new String(chars);
}
private static char createRandomChar(char minChar, char maxChar) {
return (char) (Math.random() * (maxChar - minChar + 1) + minChar);
}
}