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yacy_search_server/source/de/anomic/plasma/plasmaWordIndexCache.java

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21 KiB

// plasmaWordIndexCache.java
// -------------------------
// part of YACY
// (C) by Michael Peter Christen; mc@anomic.de
// first published on http://www.anomic.de
// Frankfurt, Germany, 2005
//
// $LastChangedDate$
// $LastChangedRevision$
// $LastChangedBy$
//
// 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
//
// Using this software in any meaning (reading, learning, copying, compiling,
// running) means that you agree that the Author(s) is (are) not responsible
// for cost, loss of data or any harm that may be caused directly or indirectly
// by usage of this softare or this documentation. The usage of this software
// is on your own risk. The installation and usage (starting/running) of this
// software may allow other people or application to access your computer and
// any attached devices and is highly dependent on the configuration of the
// software which must be done by the user of the software; the author(s) is
// (are) also not responsible for proper configuration and usage of the
// software, even if provoked by documentation provided together with
// the software.
//
// Any changes to this file according to the GPL as documented in the file
// gpl.txt aside this file in the shipment you received can be done to the
// lines that follows this copyright notice here, but changes must not be
// done inside the copyright notive above. A re-distribution must contain
// the intact and unchanged copyright notice.
// Contributions and changes to the program code must be marked as such.
package de.anomic.plasma;
import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.Map;
import java.util.TreeMap;
import de.anomic.kelondro.kelondroArray;
import de.anomic.kelondro.kelondroException;
import de.anomic.kelondro.kelondroMScoreCluster;
import de.anomic.kelondro.kelondroRecords;
import de.anomic.server.logging.serverLog;
import de.anomic.yacy.yacySeedDB;
public final class plasmaWordIndexCache implements plasmaWordIndexInterface {
// environment constants
private static final String indexArrayFileName = "indexDump1.array";
public static final int wCacheReferenceLimit = 64;
public static final long wCacheMaxAge = 1000 * 60 * 30; // milliseconds; 30 minutes
public static final long kCacheMaxAge = 1000 * 60 * 2; // milliseconds; 2 minutes
// class variables
private final File databaseRoot;
private final TreeMap wCache; // wordhash-container
private final TreeMap kCache; // time-container; for karenz/DHT caching (set with high priority)
private final kelondroMScoreCluster hashScore;
private final kelondroMScoreCluster hashDate;
private long kCacheInc = 0;
private long startTime;
private int wCacheMaxCount;
private final serverLog log;
// calculated constants
private static String maxKey;
static {
maxKey = ""; for (int i = 0; i < yacySeedDB.commonHashLength; i++) maxKey += 'z';
//minKey = ""; for (int i = 0; i < yacySeedDB.commonHashLength; i++) maxKey += '-';
}
public plasmaWordIndexCache(File databaseRoot, serverLog log) {
// creates a new index cache
// the cache has a back-end where indexes that do not fit in the cache are flushed
this.databaseRoot = databaseRoot;
this.wCache = new TreeMap();
this.kCache = new TreeMap();
this.hashScore = new kelondroMScoreCluster();
this.hashDate = new kelondroMScoreCluster();
this.kCacheInc = 0;
this.startTime = System.currentTimeMillis();
this.wCacheMaxCount = 10000;
this.log = log;
// read in dump of last session
try {
restore();
} catch (IOException e){
log.logSevere("unable to restore cache dump: " + e.getMessage(), e);
}
}
private void dump(int waitingSeconds) throws IOException {
log.logConfig("creating dump for index cache, " + wCache.size() + " words (and much more urls)");
File indexDumpFile = new File(databaseRoot, indexArrayFileName);
if (indexDumpFile.exists()) indexDumpFile.delete();
kelondroArray dumpArray = null;
dumpArray = new kelondroArray(indexDumpFile, plasmaWordIndexAssortment.bufferStructureBasis, 0, false);
long startTime = System.currentTimeMillis();
long messageTime = System.currentTimeMillis() + 5000;
long wordsPerSecond = 0, wordcount = 0, urlcount = 0;
Map.Entry entry;
String wordHash;
plasmaWordIndexEntryContainer container;
long updateTime;
plasmaWordIndexEntry wordEntry;
byte[][] row = new byte[5][];
// write kCache, this will be melted with the wCache upon load
synchronized (kCache) {
Iterator i = kCache.values().iterator();
while (i.hasNext()) {
container = (plasmaWordIndexEntryContainer) i.next();
// put entries on stack
if (container != null) {
Iterator ci = container.entries();
while (ci.hasNext()) {
wordEntry = (plasmaWordIndexEntry) ci.next();
row[0] = container.wordHash().getBytes();
row[1] = kelondroRecords.long2bytes(container.size(), 4);
row[2] = kelondroRecords.long2bytes(container.updated(), 8);
row[3] = wordEntry.getUrlHash().getBytes();
row[4] = wordEntry.toEncodedForm().getBytes();
dumpArray.set((int) urlcount++, row);
}
}
wordcount++;
i.remove(); // free some mem
}
}
// write wCache
synchronized (wCache) {
Iterator i = wCache.entrySet().iterator();
while (i.hasNext()) {
// get entries
entry = (Map.Entry) i.next();
wordHash = (String) entry.getKey();
updateTime = getUpdateTime(wordHash);
container = (plasmaWordIndexEntryContainer) entry.getValue();
// put entries on stack
if (container != null) {
Iterator ci = container.entries();
while (ci.hasNext()) {
wordEntry = (plasmaWordIndexEntry) ci.next();
row[0] = wordHash.getBytes();
row[1] = kelondroRecords.long2bytes(container.size(), 4);
row[2] = kelondroRecords.long2bytes(updateTime, 8);
row[3] = wordEntry.getUrlHash().getBytes();
row[4] = wordEntry.toEncodedForm().getBytes();
dumpArray.set((int) urlcount++, row);
}
}
wordcount++;
i.remove(); // free some mem
// write a log
if (System.currentTimeMillis() > messageTime) {
// System.gc(); // for better statistic
wordsPerSecond = wordcount * 1000 / (1 + System.currentTimeMillis() - startTime);
log.logInfo("dumping status: " + wordcount + " words done, " + (wCache.size() / (wordsPerSecond + 1)) + " seconds remaining, free mem = " + (Runtime.getRuntime().freeMemory() / 1024 / 1024) + "MB");
messageTime = System.currentTimeMillis() + 5000;
}
}
}
dumpArray.close();
dumpArray = null;
log.logConfig("dumped " + urlcount + " word/URL relations in " + ((System.currentTimeMillis() - startTime) / 1000) + " seconds");
}
private long restore() throws IOException {
File indexDumpFile = new File(databaseRoot, indexArrayFileName);
if (!(indexDumpFile.exists())) return 0;
kelondroArray dumpArray = new kelondroArray(indexDumpFile);
log.logConfig("restore array dump of index cache, " + dumpArray.size() + " word/URL relations");
long startTime = System.currentTimeMillis();
long messageTime = System.currentTimeMillis() + 5000;
long urlCount = 0, urlsPerSecond = 0;
try {
synchronized (wCache) {
int i = dumpArray.size();
String wordHash;
//long creationTime;
plasmaWordIndexEntry wordEntry;
byte[][] row;
//Runtime rt = Runtime.getRuntime();
while (i-- > 0) {
// get out one entry
row = dumpArray.get(i);
if ((row[0] == null) || (row[1] == null) || (row[2] == null) || (row[3] == null) || (row[4] == null)) continue;
wordHash = new String(row[0], "UTF-8");
//creationTime = kelondroRecords.bytes2long(row[2]);
wordEntry = new plasmaWordIndexEntry(new String(row[3], "UTF-8"), new String(row[4], "UTF-8"));
// store to cache
addEntry(wordHash, wordEntry, startTime, false);
urlCount++;
// protect against memory shortage
//while (rt.freeMemory() < 1000000) {flushFromMem(); java.lang.System.gc();}
// write a log
if (System.currentTimeMillis() > messageTime) {
System.gc(); // for better statistic
urlsPerSecond = 1 + urlCount * 1000 / (1 + System.currentTimeMillis() - startTime);
log.logInfo("restoring status: " + urlCount + " urls done, " + (i / urlsPerSecond) + " seconds remaining, free mem = " + (Runtime.getRuntime().freeMemory() / 1024 / 1024) + "MB");
messageTime = System.currentTimeMillis() + 5000;
}
}
}
dumpArray.close();
log.logConfig("restored " + wCache.size() + " words in " + ((System.currentTimeMillis() - startTime) / 1000) + " seconds");
} catch (kelondroException e) {
// restore failed
log.logSevere("restore of indexCache array dump failed: " + e.getMessage(), e);
} finally {
if (dumpArray != null) try {dumpArray.close();}catch(Exception e){}
}
return urlCount;
}
// cache settings
public int maxURLinWCache() {
if (hashScore.size() == 0) return 0;
return hashScore.getMaxScore();
}
public long minAgeOfWCache() {
if (hashDate.size() == 0) return 0;
return System.currentTimeMillis() - longEmit(hashDate.getMaxScore());
}
public long maxAgeOfWCache() {
if (hashDate.size() == 0) return 0;
return System.currentTimeMillis() - longEmit(hashDate.getMinScore());
}
public long minAgeOfKCache() {
if (kCache.size() == 0) return 0;
return System.currentTimeMillis() - ((Long) kCache.lastKey()).longValue();
}
public long maxAgeOfKCache() {
if (kCache.size() == 0) return 0;
return System.currentTimeMillis() - ((Long) kCache.firstKey()).longValue();
}
public void setMaxWordCount(int maxWords) {
this.wCacheMaxCount = maxWords;
}
public int getMaxWordCount() {
return this.wCacheMaxCount;
}
public int wSize() {
return wCache.size();
}
public int kSize() {
return kCache.size();
}
public int size() {
return wCache.size() + kCache.size();
}
public int indexSize(String wordHash) {
int size = 0;
plasmaWordIndexEntryContainer cacheIndex = (plasmaWordIndexEntryContainer) wCache.get(wordHash);
if (cacheIndex != null) size += cacheIndex.size();
return size;
}
public Iterator wordHashes(String startWordHash, boolean rot) {
if (rot) throw new UnsupportedOperationException("plasmaWordIndexCache cannot rotate");
return wCache.tailMap(startWordHash).keySet().iterator();
}
public void shiftK2W() {
// find entries in kCache that are too old for that place and shift them to the wCache
long time;
Long l;
plasmaWordIndexEntryContainer container;
synchronized (kCache) {
while (kCache.size() > 0) {
l = (Long) kCache.firstKey();
time = l.longValue();
if (System.currentTimeMillis() - time < kCacheMaxAge) return;
container = (plasmaWordIndexEntryContainer) kCache.remove(l);
addEntries(container, container.updated(), false);
}
}
}
public String bestFlushWordHash() {
// select appropriate hash
// we have 2 different methods to find a good hash:
// - the oldest entry in the cache
// - the entry with maximum count
shiftK2W();
if (wCache.size() == 0) return null;
try {
synchronized (wCache) {
String hash = null;
int count = hashScore.getMaxScore();
if ((count > wCacheReferenceLimit) &&
((hash = (String) hashScore.getMaxObject()) != null)) {
// we MUST flush high-score entries, because a loop deletes entries in cache until this condition fails
// in this cache we MUST NOT check wCacheMinAge
return hash;
}
long oldestTime = longEmit(hashDate.getMinScore());
if (((System.currentTimeMillis() - oldestTime) > wCacheMaxAge) &&
((hash = (String) hashDate.getMinObject()) != null)) {
// flush out-dated entries
return hash;
}
// cases with respect to memory situation
if (Runtime.getRuntime().freeMemory() < 1000000) {
// urgent low-memory case
hash = (String) hashScore.getMaxObject(); // flush high-score entries (saves RAM)
} else {
// not-efficient-so-far case. cleans up unnecessary cache slots
hash = (String) hashDate.getMinObject(); // flush oldest entries
}
return hash;
}
} catch (Exception e) {
log.logSevere("flushFromMem: " + e.getMessage(), e);
}
return null;
}
private int intTime(long longTime) {
return (int) Math.max(0, ((longTime - startTime) / 1000));
}
private long longEmit(int intTime) {
return (((long) intTime) * (long) 1000) + startTime;
}
public plasmaWordIndexEntryContainer getContainer(String wordHash, boolean deleteIfEmpty) {
return (plasmaWordIndexEntryContainer) wCache.get(wordHash);
}
public long getUpdateTime(String wordHash) {
plasmaWordIndexEntryContainer entries = (plasmaWordIndexEntryContainer) wCache.get(wordHash);
if (entries == null) return 0;
return entries.updated();
/*
Long time = new Long(longTime(hashDate.getScore(wordHash)));
if (time == null) return 0;
return time.longValue();
*/
}
public plasmaWordIndexEntryContainer deleteContainer(String wordHash) {
// returns the index that had been deleted
synchronized (wCache) {
plasmaWordIndexEntryContainer container = (plasmaWordIndexEntryContainer) wCache.remove(wordHash);
hashScore.deleteScore(wordHash);
hashDate.deleteScore(wordHash);
return container;
}
}
public int removeEntries(String wordHash, String[] urlHashes, boolean deleteComplete) {
if (urlHashes.length == 0) return 0;
int count = 0;
synchronized (wCache) {
plasmaWordIndexEntryContainer c = (plasmaWordIndexEntryContainer) deleteContainer(wordHash);
if (c != null) {
count = c.removeEntries(wordHash, urlHashes, deleteComplete);
if (c.size() != 0) this.addEntries(c, System.currentTimeMillis(), false);
}
}
return count;
}
public int tryRemoveURLs(String urlHash) {
// this tries to delete an index from the cache that has this
// urlHash assigned. This can only work if the entry is really fresh
// Such entries must be searched in the latest entries
int delCount = 0;
synchronized (kCache) {
Iterator i = kCache.entrySet().iterator();
Map.Entry entry;
Long l;
plasmaWordIndexEntryContainer c;
while (i.hasNext()) {
entry = (Map.Entry) i.next();
l = (Long) entry.getKey();
// get container
c = (plasmaWordIndexEntryContainer) entry.getValue();
if (c.remove(urlHash) != null) {
if (c.size() == 0) {
i.remove();
} else {
kCache.put(l, c); // superfluous?
}
delCount++;
}
}
}
return delCount;
}
public int addEntries(plasmaWordIndexEntryContainer container, long updateTime, boolean dhtCase) {
// this puts the entries into the cache, not into the assortment directly
int added = 0;
// put new words into cache
if (dhtCase) synchronized (kCache) {
// put container into kCache
kCache.put(new Long(updateTime + kCacheInc), container);
kCacheInc++;
if (kCacheInc > 10000) kCacheInc = 0;
added = container.size();
} else synchronized (wCache) {
// put container into wCache
String wordHash = container.wordHash();
plasmaWordIndexEntryContainer entries = (plasmaWordIndexEntryContainer) wCache.get(wordHash); // null pointer exception? wordhash != null! must be cache==null
if (entries == null) entries = new plasmaWordIndexEntryContainer(wordHash);
added = entries.add(container, -1);
if (added > 0) {
wCache.put(wordHash, entries);
hashScore.addScore(wordHash, added);
hashDate.setScore(wordHash, intTime(updateTime));
}
entries = null;
}
return added;
}
public boolean addEntry(String wordHash, plasmaWordIndexEntry newEntry, long updateTime, boolean dhtCase) {
if (dhtCase) synchronized (kCache) {
// put container into kCache
plasmaWordIndexEntryContainer container = new plasmaWordIndexEntryContainer(wordHash);
container.add(newEntry);
kCache.put(new Long(updateTime + kCacheInc), container);
kCacheInc++;
if (kCacheInc > 10000) kCacheInc = 0;
return true;
} else synchronized (wCache) {
plasmaWordIndexEntryContainer container = (plasmaWordIndexEntryContainer) wCache.get(wordHash);
if (container == null) container = new plasmaWordIndexEntryContainer(wordHash);
plasmaWordIndexEntry[] entries = new plasmaWordIndexEntry[] { newEntry };
if (container.add(entries, updateTime) > 0) {
wCache.put(wordHash, container);
hashScore.incScore(wordHash);
hashDate.setScore(wordHash, intTime(updateTime));
return true;
}
container = null;
entries = null;
return false;
}
}
public void close(int waitingSeconds) {
// dump cache
try {
dump(waitingSeconds);
} catch (IOException e){
log.logSevere("unable to dump cache: " + e.getMessage(), e);
}
}
}