// kelondroRowCollection.java
// (C) 2006 by Michael Peter Christen; mc@anomic.de, Frankfurt a. M., Germany
// first published 12.01.2006 on http://www.anomic.de
//
// $LastChangedDate: 2006-04-02 22:40:07 +0200 (So, 02 Apr 2006) $
// $LastChangedRevision: 1986 $
// $LastChangedBy: orbiter $
//
// LICENSE
//
// 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; either version 2 of the License, or
// (at your option) any later version.
//
// 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 de.anomic.kelondro;
import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import de.anomic.server.serverFileUtils;
import de.anomic.server.serverMemory;
import de.anomic.server.logging.serverLog;
public class kelondroRowCollection {
public static final double growfactor = 1.4;
protected byte[] chunkcache;
protected int chunkcount;
protected long lastTimeRead, lastTimeWrote;
protected kelondroRow rowdef;
protected int sortBound;
private static final int exp_chunkcount = 0;
private static final int exp_last_read = 1;
private static final int exp_last_wrote = 2;
private static final int exp_order_type = 3;
private static final int exp_order_col = 4;
private static final int exp_order_bound = 5;
private static final int exp_collection = 6;
public kelondroRowCollection(kelondroRowCollection rc) {
this.rowdef = rc.rowdef;
this.chunkcache = rc.chunkcache;
this.chunkcount = rc.chunkcount;
this.sortBound = rc.sortBound;
this.lastTimeRead = rc.lastTimeRead;
this.lastTimeWrote = rc.lastTimeWrote;
}
public kelondroRowCollection(kelondroRow rowdef, int objectCount) {
this.rowdef = rowdef;
this.chunkcache = new byte[objectCount * rowdef.objectsize()];
this.chunkcount = 0;
this.sortBound = 0;
this.lastTimeRead = System.currentTimeMillis();
this.lastTimeWrote = System.currentTimeMillis();
}
public kelondroRowCollection(kelondroRow rowdef, int objectCount, byte[] cache, int sortBound) {
this.rowdef = rowdef;
this.chunkcache = cache;
this.chunkcount = objectCount;
this.sortBound = sortBound;
this.lastTimeRead = System.currentTimeMillis();
this.lastTimeWrote = System.currentTimeMillis();
}
public kelondroRowCollection(kelondroRow rowdef, kelondroRow.Entry exportedCollectionRowEnvironment, int columnInEnvironment) {
this.rowdef = rowdef;
int chunkcachelength = exportedCollectionRowEnvironment.cellwidth(columnInEnvironment) - exportOverheadSize;
kelondroRow.Entry exportedCollection = exportRow(chunkcachelength).newEntry(exportedCollectionRowEnvironment, columnInEnvironment);
this.chunkcount = (int) exportedCollection.getColLong(exp_chunkcount);
//assert (this.chunkcount <= chunkcachelength / rowdef.objectsize) : "chunkcount = " + this.chunkcount + ", chunkcachelength = " + chunkcachelength + ", rowdef.objectsize = " + rowdef.objectsize;
if ((this.chunkcount > chunkcachelength / rowdef.objectsize)) {
serverLog.logWarning("RowCollection", "corrected wrong chunkcount; chunkcount = " + this.chunkcount + ", chunkcachelength = " + chunkcachelength + ", rowdef.objectsize = " + rowdef.objectsize);
this.chunkcount = chunkcachelength / rowdef.objectsize; // patch problem
}
this.lastTimeRead = (exportedCollection.getColLong(exp_last_read) + 10957) * day;
this.lastTimeWrote = (exportedCollection.getColLong(exp_last_wrote) + 10957) * day;
String sortOrderKey = exportedCollection.getColString(exp_order_type, null);
kelondroOrder oldOrder = null;
if ((sortOrderKey == null) || (sortOrderKey.equals("__"))) {
oldOrder = null;
} else {
oldOrder = kelondroNaturalOrder.bySignature(sortOrderKey);
if (oldOrder == null) oldOrder = kelondroBase64Order.bySignature(sortOrderKey);
}
if ((rowdef.objectOrder != null) && (oldOrder != null) && (!(rowdef.objectOrder.signature().equals(oldOrder.signature()))))
throw new kelondroException("old collection order does not match with new order");
if (rowdef.primaryKey != (int) exportedCollection.getColLong(exp_order_col))
throw new kelondroException("old collection primary key does not match with new primary key");
this.sortBound = (int) exportedCollection.getColLong(exp_order_bound);
//assert (sortBound <= chunkcount) : "sortBound = " + sortBound + ", chunkcount = " + chunkcount;
if (sortBound > chunkcount) {
serverLog.logWarning("RowCollection", "corrected wrong sortBound; sortBound = " + sortBound + ", chunkcount = " + chunkcount);
this.sortBound = chunkcount;
}
this.chunkcache = exportedCollection.getColBytes(exp_collection);
}
public void reset() {
this.chunkcache = new byte[0];
this.chunkcount = 0;
this.sortBound = 0;
}
private static final kelondroRow exportMeasureRow = exportRow(0 /* no relevance */);
protected static final int sizeOfExportedCollectionRows(kelondroRow.Entry exportedCollectionRowEnvironment, int columnInEnvironment) {
kelondroRow.Entry exportedCollectionEntry = exportMeasureRow.newEntry(exportedCollectionRowEnvironment, columnInEnvironment);
int chunkcount = (int) exportedCollectionEntry.getColLong(exp_chunkcount);
return chunkcount;
}
private static final long day = 1000 * 60 * 60 * 24;
public static int daysSince2000(long time) {
return (int) (time / day) - 10957;
}
private static kelondroRow exportRow(int chunkcachelength) {
// find out the size of this collection
return new kelondroRow(
"int size-4 {b256}," +
"short lastread-2 {b256}," + // as daysSince2000
"short lastwrote-2 {b256}," + // as daysSince2000
"byte[] orderkey-2," +
"short ordercol-2 {b256}," +
"short orderbound-2 {b256}," +
"byte[] collection-" + chunkcachelength,
kelondroNaturalOrder.naturalOrder, 0
);
}
public static final int exportOverheadSize = 14;
public synchronized byte[] exportCollection() {
// returns null if the collection is empty
trim(false);
kelondroRow row = exportRow(chunkcache.length);
kelondroRow.Entry entry = row.newEntry();
assert (sortBound <= chunkcount) : "sortBound = " + sortBound + ", chunkcount = " + chunkcount;
assert (this.chunkcount <= chunkcache.length / rowdef.objectsize) : "chunkcount = " + this.chunkcount + ", chunkcache.length = " + chunkcache.length + ", rowdef.objectsize = " + rowdef.objectsize;
entry.setCol(exp_chunkcount, this.chunkcount);
entry.setCol(exp_last_read, daysSince2000(this.lastTimeRead));
entry.setCol(exp_last_wrote, daysSince2000(this.lastTimeWrote));
entry.setCol(exp_order_type, (this.rowdef.objectOrder == null) ? "__".getBytes() :this.rowdef.objectOrder.signature().getBytes());
entry.setCol(exp_order_col, this.rowdef.primaryKey);
entry.setCol(exp_order_bound, this.sortBound);
entry.setCol(exp_collection, this.chunkcache);
return entry.bytes();
}
public void saveCollection(File file) throws IOException {
serverFileUtils.write(exportCollection(), file);
}
public kelondroRow row() {
return this.rowdef;
}
private final void ensureSize(int elements) {
int needed = elements * rowdef.objectsize();
if (chunkcache.length >= needed) return;
byte[] newChunkcache = new byte[(int) (needed * growfactor)]; // increase space
System.arraycopy(chunkcache, 0, newChunkcache, 0, chunkcache.length);
chunkcache = newChunkcache;
newChunkcache = null;
}
/*
private static final Object[] arraydepot = new Object[]{new byte[0]};
private final void ensureSize(int elements) {
int needed = elements * rowdef.objectsize();
if (chunkcache.length >= needed) return;
long neededRAM = (long) (needed * growfactor);
long availableRAM = serverMemory.available();
//if ((safemode) && (neededRAM > availableRAM)) throw new kelondroMemoryProtectionException("rowCollection temporary chunkcache", neededRAM, availableRAM);
if (neededRAM > availableRAM) {
// go into safe mode: use the arraydepot
synchronized (arraydepot) {
if (((byte[]) arraydepot[0]).length >= neededRAM) {
System.out.println("ensureSize case 1");
// use the depot to increase the chunkcache
byte[] newChunkcache = (byte[]) arraydepot[0];
System.arraycopy(chunkcache, 0, newChunkcache, 0, chunkcache.length);
// safe the chunkcache for later use in arraydepot
arraydepot[0] = chunkcache;
chunkcache = newChunkcache;
newChunkcache = null;
} else {
System.out.println("ensureSize case 2");
// this is the critical part: we need more RAM.
// do a buffering using the arraydepot
byte[] buffer0 = (byte[]) arraydepot[0];
byte[] buffer1 = new byte[chunkcache.length - buffer0.length];
// first copy the previous chunkcache to the two buffers
System.arraycopy(chunkcache, 0, buffer0, 0, buffer0.length);
System.arraycopy(chunkcache, buffer0.length, buffer1, 0, buffer1.length);
// then free the previous chunkcache and replace it with a new array at target size
chunkcache = null; // hand this over to GC
chunkcache = new byte[(int) neededRAM];
System.arraycopy(buffer0, 0, chunkcache, 0, buffer0.length);
System.arraycopy(buffer1, 0, chunkcache, buffer0.length, buffer1.length);
// then move the bigger buffer into the arraydepot
if (buffer0.length > buffer1.length) {
arraydepot[0] = buffer0;
} else {
arraydepot[1] = buffer1;
}
buffer0 = null;
buffer1 = null;
}
}
} else {
// there is enough memory available
byte[] newChunkcache = new byte[(int) neededRAM]; // increase space
System.arraycopy(chunkcache, 0, newChunkcache, 0, chunkcache.length);
// safe the chunkcache for later use in arraydepot
synchronized (arraydepot) {
if (((byte[]) arraydepot[0]).length < chunkcache.length) {
System.out.println("ensureSize case 0");
arraydepot[0] = chunkcache;
}
}
chunkcache = newChunkcache;
newChunkcache = null;
}
}
*/
public final long memoryNeededForGrow() {
return (long) ((((long) (chunkcount + 1)) * ((long) rowdef.objectsize())) * growfactor);
}
public synchronized void trim(boolean plusGrowFactor) {
if (chunkcache.length == 0)
return;
int needed = chunkcount * rowdef.objectsize();
if (plusGrowFactor)
needed = (int) (needed * growfactor);
if (needed >= chunkcache.length)
return; // in case that the growfactor causes that the cache would
// grow instead of shrink, simply ignore the growfactor
if (serverMemory.available() + 1000 < needed)
return; // if the swap buffer is not available, we must give up.
// This is not critical. Othervise we provoke a serious
// problem with OOM
byte[] newChunkcache = new byte[needed];
System.arraycopy(chunkcache, 0, newChunkcache, 0, Math.min(
chunkcache.length, newChunkcache.length));
chunkcache = newChunkcache;
newChunkcache = null;
}
public final long lastRead() {
return lastTimeRead;
}
public final long lastWrote() {
return lastTimeWrote;
}
public synchronized final kelondroRow.Entry get(int index) {
assert (index >= 0) : "get: access with index " + index + " is below zero";
assert (index < chunkcount) : "get: access with index " + index + " is above chunkcount " + chunkcount + "; sortBound = " + sortBound;
assert (index * rowdef.objectsize < chunkcache.length);
if (index >= chunkcount) return null;
if (index * rowdef.objectsize() >= chunkcache.length) return null;
this.lastTimeRead = System.currentTimeMillis();
return rowdef.newEntry(chunkcache, index * rowdef.objectsize(), true);
}
public synchronized final void set(int index, kelondroRow.Entry a) {
assert (index >= 0) : "get: access with index " + index + " is below zero";
assert (index < chunkcount) : "get: access with index " + index + " is above chunkcount " + chunkcount;
//assert (!(bugappearance(a, astart, alength))) : "a = " + serverLog.arrayList(a, astart, alength);
//if (bugappearance(a, astart, alength)) return; // TODO: this is temporary; remote peers may still submit bad entries
a.writeToArray(chunkcache, index * rowdef.objectsize());
this.lastTimeWrote = System.currentTimeMillis();
}
public synchronized void addUnique(kelondroRow.Entry row) {
byte[] r = row.bytes();
addUnique(r, 0, r.length);
}
public synchronized void addUniqueMultiple(List rows) {
assert this.sortBound == 0 : "sortBound = " + this.sortBound + ", chunkcount = " + this.chunkcount;
Iterator i = rows.iterator();
while (i.hasNext()) addUnique((kelondroRow.Entry) i.next());
}
public synchronized void add(byte[] a) {
addUnique(a, 0, a.length);
}
private final void addUnique(byte[] a, int astart, int alength) {
assert (a != null);
assert (astart >= 0) && (astart < a.length) : " astart = " + a;
assert (!(serverLog.allZero(a, astart, alength))) : "a = " + serverLog.arrayList(a, astart, alength);
assert (alength > 0);
assert (astart + alength <= a.length);
if (bugappearance(a, astart, alength)) {
System.out.println("*** DEBUG: patched wrong a = " + serverLog.arrayList(a, astart, alength));
return; // TODO: this is temporary; remote peers may still submit bad entries
}
assert (!(bugappearance(a, astart, alength))) : "a = " + serverLog.arrayList(a, astart, alength);
int l = Math.min(rowdef.objectsize(), Math.min(alength, a.length - astart));
ensureSize(chunkcount + 1);
System.arraycopy(a, astart, chunkcache, rowdef.objectsize() * chunkcount, l);
chunkcount++;
this.lastTimeWrote = System.currentTimeMillis();
}
private static boolean bugappearance(byte[] a, int astart, int alength) {
// check strange appearances of '@[B', which is not a b64-value or any other hash fragment
if (astart + 3 > alength) return false;
loop: for (int i = astart; i <= alength - 3; i++) {
if (a[i ] != 64) continue loop;
if (a[i + 1] != 91) continue loop;
if (a[i + 2] != 66) continue loop;
return true;
}
return false;
}
public synchronized final void addAllUnique(kelondroRowCollection c) {
if (c == null) return;
assert(rowdef.objectsize() == c.rowdef.objectsize());
ensureSize(chunkcount + c.size());
System.arraycopy(c.chunkcache, 0, chunkcache, rowdef.objectsize() * chunkcount, rowdef.objectsize() * c.size());
chunkcount += c.size();
}
protected synchronized final void removeRow(int p) {
assert p >= 0 : "p = " + p;
assert p < chunkcount : "p = " + p + ", chunkcount = " + chunkcount;
assert chunkcount > 0 : "chunkcount = " + chunkcount;
assert sortBound <= chunkcount : "sortBound = " + sortBound + ", chunkcount = " + chunkcount;
if (p < sortBound) {
// remove by shift
System.arraycopy(
chunkcache, (p + 1) * this.rowdef.objectsize(),
chunkcache, p * this.rowdef.objectsize(),
(chunkcount - p - 1) * this.rowdef.objectsize());
sortBound--;
} else {
// remove by copying the top-element to the remove position
if (p != chunkcount - 1) {
System.arraycopy(
chunkcache, (chunkcount - 1) * this.rowdef.objectsize(),
chunkcache, p * this.rowdef.objectsize(),
this.rowdef.objectsize());
}
}
chunkcount--;
this.lastTimeWrote = System.currentTimeMillis();
}
public synchronized kelondroRow.Entry removeOne() {
if (chunkcount == 0) return null;
kelondroRow.Entry r = get(chunkcount - 1);
if (chunkcount == sortBound) sortBound--;
chunkcount--;
this.lastTimeWrote = System.currentTimeMillis();
return r;
}
public synchronized void clear() {
if (this.chunkcache.length == 0) return;
this.chunkcache = new byte[0];
this.chunkcount = 0;
this.sortBound = 0;
this.lastTimeWrote = System.currentTimeMillis();
}
public int size() {
return chunkcount;
}
public synchronized Iterator rows() {
// iterates kelondroRow.Entry - type entries
return new rowIterator();
}
public class rowIterator implements Iterator {
private int p;
public rowIterator() {
p = 0;
}
public boolean hasNext() {
return p < chunkcount;
}
public Object next() {
return get(p++);
}
public void remove() {
p--;
removeRow(p);
}
}
public synchronized void select(Set keys) {
// removes all entries but the ones given by urlselection
if ((keys == null) || (keys.size() == 0)) return;
Iterator i = rows();
kelondroRow.Entry row;
while (i.hasNext()) {
row = (kelondroRow.Entry) i.next();
if (!(keys.contains(row.getColString(0, null)))) i.remove();
}
}
public synchronized final void sort() {
assert (this.rowdef.objectOrder != null);
if (this.sortBound == this.chunkcount) return; // this is already sorted
//System.out.println("SORT(chunkcount=" + this.chunkcount + ", sortBound=" + this.sortBound + ")");
if (this.sortBound > 1) {
qsort(0, this.sortBound, this.chunkcount);
} else {
qsort(0, this.chunkcount);
}
this.sortBound = this.chunkcount;
}
private final void qsort(int L, int S, int R) {
//System.out.println("QSORT: chunkcache.length=" + chunkcache.length + ", chunksize=" + chunksize + ", L=" + L + ", S=" + S + ", R=" + R);
assert (S <= R) : "S > R: S = " + S + ", R = " + R;
if (L >= R - 1) return;
if (S >= R) return;
if (R - L < 20) {
isort(L, R);
return;
}
int p = L + ((S - L) / 2);
int ps = p;
int q = S;
int qs = q;
int pivot = p;
while (q < R) {
if (compare(pivot, q) < 1) {
q++;
} else {
pivot = swap(p, q, pivot);
p++;
q++;
}
}
if ((ps - L) <= ((p - L) / 2)) qsort(L, p); else qsort(L, ps, p);
if ((qs - p) <= ((R - p) / 2)) qsort(p, R); else qsort(p, qs, R);
}
private final void qsort(int L, int R) {
//System.out.println("QSORT: chunkcache.length=" + chunkcache.length + ", L=" + L + "/" + new String(this.chunkcache, L * this.rowdef.objectsize(), this.rowdef.width(0)) + ", R=" + R + "/" + new String(this.chunkcache, (R - 1) * this.rowdef.objectsize(), this.rowdef.width(0)));
/*
if ((L == 190) && (R == 258)) {
for (int i = L; i < R; i++) {
System.out.print(new String(this.chunkcache, L * this.chunksize, this.chunksize) + ", ");
}
System.out.println();
}
*/
if (L >= R - 1) return;
if (R - L < 20) {
isort(L, R);
return;
}
int i = L;
int j = R - 1;
int pivot = (i + j) / 2;
//System.out.println("Pivot=" + pivot + "/" + new String(this.chunkcache, pivot * this.rowdef.objectsize(), this.rowdef.width(0)));
while (i <= j) {
while (compare(pivot, i) == 1) i++; // chunkAt[i] < keybuffer
while (compare(pivot, j) == -1) j--; // chunkAt[j] > keybuffer
//if (L == 6693) System.out.println(i + ", " + j);
if (i <= j) {
pivot = swap(i, j, pivot);
i++;
j--;
}
}
//if (L == 6693) System.out.println(i);
qsort(L, i);
qsort(i, R);
}
private final void isort(int L, int R) {
for (int i = L + 1; i < R; i++)
for (int j = i; j > L && compare(j - 1, j) > 0; j--)
swap(j, j - 1, 0);
}
private final int swap(int i, int j, int p) {
if (i == j) return p;
if ((this.chunkcount + 1) * this.rowdef.objectsize() < this.chunkcache.length) {
// there is space in the chunkcache that we can use as buffer
System.arraycopy(chunkcache, this.rowdef.objectsize() * i, chunkcache, chunkcache.length - this.rowdef.objectsize(), this.rowdef.objectsize());
System.arraycopy(chunkcache, this.rowdef.objectsize() * j, chunkcache, this.rowdef.objectsize() * i, this.rowdef.objectsize());
System.arraycopy(chunkcache, chunkcache.length - this.rowdef.objectsize(), chunkcache, this.rowdef.objectsize() * j, this.rowdef.objectsize());
} else {
// allocate a chunk to use as buffer
byte[] a = new byte[this.rowdef.objectsize()];
System.arraycopy(chunkcache, this.rowdef.objectsize() * i, a, 0, this.rowdef.objectsize());
System.arraycopy(chunkcache, this.rowdef.objectsize() * j, chunkcache, this.rowdef.objectsize() * i, this.rowdef.objectsize());
System.arraycopy(a, 0, chunkcache, this.rowdef.objectsize() * j, this.rowdef.objectsize());
}
if (i == p) return j; else if (j == p) return i; else return p;
}
public synchronized void uniq(long maxtime) {
assert (this.rowdef.objectOrder != null);
// removes double-occurrences of chunks
// this works only if the collection was ordered with sort before
// if the collection is large and the number of deletions is also large,
// then this method may run a long time with 100% CPU load which is caused
// by the large number of memory movements. Therefore it is possible
// to assign a runtime limitation
long start = System.currentTimeMillis();
if (chunkcount <= 1) return;
int i = 0;
while (i < chunkcount - 1) {
//System.out.println("ENTRY0: " + serverLog.arrayList(chunkcache, rowdef.objectsize*i, rowdef.objectsize));
//System.out.println("ENTRY1: " + serverLog.arrayList(chunkcache, rowdef.objectsize*(i+1), rowdef.objectsize));
if (compare(i, i + 1) == 0) {
removeRow(i); // this decreases the chunkcount
} else {
i++;
}
if ((maxtime > 0) && (start + maxtime < System.currentTimeMillis())) break;
}
}
public synchronized String toString() {
StringBuffer s = new StringBuffer();
Iterator i = rows();
if (i.hasNext()) s.append(((kelondroRow.Entry) i.next()).toString());
while (i.hasNext()) s.append(", " + ((kelondroRow.Entry) i.next()).toString());
return new String(s);
}
private final int compare(int i, int j) {
assert (chunkcount * this.rowdef.objectsize() <= chunkcache.length) : "chunkcount = " + chunkcount + ", objsize = " + this.rowdef.objectsize() + ", chunkcache.length = " + chunkcache.length;
assert (i >= 0) && (i < chunkcount) : "i = " + i + ", chunkcount = " + chunkcount;
assert (j >= 0) && (j < chunkcount) : "j = " + j + ", chunkcount = " + chunkcount;
assert (this.rowdef.objectOrder != null);
if (i == j) return 0;
assert (this.rowdef.primaryKey == 0) : "this.sortColumn = " + this.rowdef.primaryKey;
int keylength = this.rowdef.width(this.rowdef.primaryKey);
int colstart = this.rowdef.colstart[this.rowdef.primaryKey];
if (bugappearance(chunkcache, i * this.rowdef.objectsize() + colstart, keylength)) throw new kelondroException("bugappearance i");
if (bugappearance(chunkcache, j * this.rowdef.objectsize() + colstart, keylength)) throw new kelondroException("bugappearance j");
int c = this.rowdef.objectOrder.compare(
chunkcache,
i * this.rowdef.objectsize() + colstart,
keylength,
chunkcache,
j * this.rowdef.objectsize() + colstart,
keylength);
return c;
}
protected synchronized int compare(byte[] a, int astart, int alength, int chunknumber) {
assert (chunknumber < chunkcount);
int l = Math.min(this.rowdef.width(rowdef.primaryKey), Math.min(a.length - astart, alength));
return rowdef.objectOrder.compare(a, astart, l, chunkcache, chunknumber * this.rowdef.objectsize() + this.rowdef.colstart[rowdef.primaryKey], this.rowdef.width(rowdef.primaryKey));
}
protected synchronized boolean match(byte[] a, int astart, int alength, int chunknumber) {
if (chunknumber >= chunkcount) return false;
int i = 0;
int p = chunknumber * this.rowdef.objectsize() + this.rowdef.colstart[rowdef.primaryKey];
final int len = Math.min(this.rowdef.width(rowdef.primaryKey), Math.min(alength, a.length - astart));
while (i < len) if (a[astart + i++] != chunkcache[p++]) return false;
return ((len == this.rowdef.width(rowdef.primaryKey)) || (chunkcache[len] == 0)) ;
}
public synchronized void close() {
chunkcache = null;
}
public static void main(String[] args) {
System.out.println(new java.util.Date(10957 * day));
System.out.println(new java.util.Date(0));
System.out.println(daysSince2000(System.currentTimeMillis()));
}
}