// 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
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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.kelondroMergeIterator;
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";
private static final String oldSingletonFileName = "indexSingletons0.db";
private static final String newSingletonFileName = "indexAssortment001.db";
private static final String indexAssortmentClusterPath = "ACLUSTER";
private static final int assortmentCount = 64;
private static final int ramCacheLimit = 200;
// class variables
private final File databaseRoot;
private final plasmaWordIndexInterface backend;
private final TreeMap cache;
private final kelondroMScoreCluster hashScore;
private final kelondroMScoreCluster hashDate;
private long startTime;
private int maxWordsLow, maxWordsHigh; // we have 2 cache limits for different priorities
private final serverLog log;
private final plasmaWordIndexAssortmentCluster assortmentCluster;
private int assortmentBufferSize; //kb
private final flush flushThread;
// calculated constants
private static String minKey, 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, plasmaWordIndexInterface backend, int assortmentbufferkb, serverLog log) {
// migrate#1
File oldSingletonFile = new File(databaseRoot, oldSingletonFileName);
File newSingletonFile = new File(databaseRoot, newSingletonFileName);
if ((oldSingletonFile.exists()) && (!(newSingletonFile.exists()))) oldSingletonFile.renameTo(newSingletonFile);
// create new assortment cluster path
File assortmentClusterPath = new File(databaseRoot, indexAssortmentClusterPath);
if (!(assortmentClusterPath.exists())) assortmentClusterPath.mkdirs();
// migrate#2
File acSingletonFile = new File(assortmentClusterPath, newSingletonFileName);
if ((newSingletonFile.exists()) && (!(acSingletonFile.exists()))) newSingletonFile.renameTo(acSingletonFile);
// create flushing thread
flushThread = new flush();
// 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.assortmentBufferSize = assortmentbufferkb;
this.cache = new TreeMap();
this.hashScore = new kelondroMScoreCluster();
this.hashDate = new kelondroMScoreCluster();
this.startTime = System.currentTimeMillis();
this.maxWordsLow = 8000;
this.maxWordsHigh = 10000;
this.backend = backend;
this.log = log;
this.assortmentCluster = new plasmaWordIndexAssortmentCluster(assortmentClusterPath, assortmentCount, assortmentBufferSize, log);
// read in dump of last session
try {
restore();
} catch (IOException e){
log.logSevere("unable to restore cache dump: " + e.getMessage(), e);
}
// start permanent flushing
flushThread.start();
}
private void dump(int waitingSeconds) throws IOException {
log.logConfig("creating dump for index cache, " + cache.size() + " words (and much more urls)");
File indexDumpFile = new File(databaseRoot, indexArrayFileName);
if (indexDumpFile.exists()) indexDumpFile.delete();
kelondroArray dumpArray = null;
try {
dumpArray = new kelondroArray(indexDumpFile, plasmaWordIndexAssortment.bufferStructureBasis, 0);
long startTime = System.currentTimeMillis();
long messageTime = System.currentTimeMillis() + 5000;
long wordsPerSecond = 0, wordcount = 0, urlcount = 0;
synchronized (cache) {
Iterator i = cache.entrySet().iterator();
Map.Entry entry;
String wordHash;
plasmaWordIndexEntryContainer container;
long updateTime;
plasmaWordIndexEntry wordEntry;
byte[][] row = new byte[5][];
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(true).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, " + (cache.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");
} finally {
if (dumpArray != null) try {dumpArray.close();}catch(Exception e){}
}
}
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 (cache) {
int i = dumpArray.size();
String wordHash;
plasmaWordIndexEntryContainer container;
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]);
creationTime = kelondroRecords.bytes2long(row[2]);
wordEntry = new plasmaWordIndexEntry(new String(row[3]), new String(row[4]));
// store to cache
addEntry(wordHash, wordEntry, creationTime);
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 " + cache.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;
}
public void intermission(long pause) {
flushThread.intermission(pause);
}
// cache settings
public int maxURLinWordCache() {
return hashScore.getScore(hashScore.getMaxObject());
}
public int wordCacheRAMSize() {
return cache.size();
}
public void setMaxWords(int maxWordsLow, int maxWordsHigh) {
this.maxWordsLow = maxWordsLow;
this.maxWordsHigh = maxWordsHigh;
}
public int[] assortmentsSizes() {
return assortmentCluster.sizes();
}
public int[] assortmentsCacheChunkSizeAvg() {
return assortmentCluster.cacheChunkSizeAvg();
}
public int[] assortmentsCacheFillStatusCml() {
return assortmentCluster.cacheFillStatusCml();
}
public int size() {
return java.lang.Math.max(assortmentCluster.sizeTotal(), java.lang.Math.max(backend.size(), cache.size()));
}
public Iterator wordHashes(String startWordHash, boolean up) {
// here we merge 3 databases into one view:
// - the RAM Cache
// - the assortmentCluster File Cache
// - the backend
if (!(up)) throw new RuntimeException("plasmaWordIndexCache.wordHashes can only count up");
return new kelondroMergeIterator(
new kelondroMergeIterator(
cache.tailMap(startWordHash).keySet().iterator(),
assortmentCluster.hashConjunction(startWordHash, true),
true),
backend.wordHashes(startWordHash, true),
true);
}
private final class flush extends Thread {
boolean terminate, pause;
long intermission;
public flush() {
terminate = false;
intermission = 0;
this.setName(this.getClass().getName());
}
public void intermission(long pause) {
this.intermission = System.currentTimeMillis() + pause;
}
public void run() {
String nextHash;
Runtime rt = Runtime.getRuntime();
long pausetime;
while (!terminate) {
if (intermission > 0) {
if (this.intermission > System.currentTimeMillis()) {
try {this.sleep(this.intermission - System.currentTimeMillis());} catch (InterruptedException e) {}
}
this.intermission = 0;
}
if (pause) {
try {this.sleep(300);} catch (InterruptedException e) {}
} else {
flushFromMem();
try {
pausetime = 1 + java.lang.Math.min(1000, 5 * maxWordsHigh/(cache.size() + 1));
if (cache.size() == 0) pausetime = 2000;
this.sleep(pausetime);
} catch (InterruptedException e) {}
}
}
}
public void pause() {
pause = true;
}
public void proceed() {
pause = false;
}
public void terminate() {
terminate = true;
}
}
private void flushFromMem() {
// select appropriate hash
// we have 2 different methods to find a good hash:
// - the oldest entry in the cache
// - the entry with maximum count
if (cache.size() == 0) return;
flushThread.pause();
try {
String hash = (String) hashScore.getMaxObject();
if (hash == null) {
flushThread.proceed();
return;
}
int count = hashScore.getMaxScore();
long time = longTime(hashDate.getScore(hash));
if ((count > ramCacheLimit) ||
((count > assortmentCount) && (System.currentTimeMillis() - time > 10000))) {
// flush high-score entries
flushFromMem(hash);
} else {
// flush oldest entries
hash = (String) hashDate.getMinObject();
flushFromMem(hash);
}
} catch (Exception e) {
log.logSevere("flushFromMem: " + e.getMessage(), e);
}
flushThread.proceed();
}
private int flushFromMem(String key) {
// this method flushes indexes out from the ram to the disc.
plasmaWordIndexEntryContainer container = null;
long time;
synchronized (cache) {
// get the container
container = (plasmaWordIndexEntryContainer) cache.get(key);
if (container == null) return 0; // flushing of nonexisting key
time = getUpdateTime(key);
// remove it from the cache
cache.remove(key);
hashScore.deleteScore(key);
hashDate.deleteScore(key);
}
// now decide where to flush that container
//if (container.size() <= assortmentCluster.clusterCapacity) {
// this fits into the assortments
plasmaWordIndexEntryContainer feedback = assortmentCluster.storeTry(key, container);
if (feedback == null) {
return container.size();
} else {
// *** should care about another option here ***
return backend.addEntries(feedback, time, true);
}
/*
} else {
// store to back-end; this should be a rare case
return backend.addEntries(container, time, true);
}
**/
}
private int intTime(long longTime) {
return (int) ((longTime - startTime) / 1000);
}
private long longTime(int intTime) {
return ((long) intTime) * ((long) 1000) + startTime;
}
private boolean flushFromAssortmentCluster(String key, long maxTime) {
// this should only be called if the assortment shall be deleted or returned in an index entity
maxTime = 8 * maxTime / 10; // reserve time for later adding to backend
plasmaWordIndexEntryContainer container = assortmentCluster.removeFromAll(key, maxTime);
if (container == null) {
return false;
} else {
// we have a non-empty entry-container
// integrate it to the backend
return backend.addEntries(container, container.updated(), true) > 0;
}
}
public plasmaWordIndexEntity getIndex(String wordHash, boolean deleteIfEmpty, long maxTime) {
flushThread.pause();
long start = System.currentTimeMillis();
flushFromMem(wordHash);
if (maxTime < 0) {
flushFromAssortmentCluster(wordHash, -1);
} else {
long remaining = maxTime - (System.currentTimeMillis() - start);
if (remaining > 0) flushFromAssortmentCluster(wordHash, remaining);
}
flushThread.proceed();
long r = maxTime - (System.currentTimeMillis() - start);
return backend.getIndex(wordHash, deleteIfEmpty, (r < 0) ? 0 : r);
}
public long getUpdateTime(String wordHash) {
plasmaWordIndexEntryContainer entries = (plasmaWordIndexEntryContainer) cache.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 void deleteIndex(String wordHash) {
flushThread.pause();
synchronized (cache) {
cache.remove(wordHash);
hashScore.deleteScore(wordHash);
hashDate.deleteScore(wordHash);
}
assortmentCluster.removeFromAll(wordHash, -1);
backend.deleteIndex(wordHash);
flushThread.proceed();
}
public synchronized int removeEntries(String wordHash, String[] urlHashes, boolean deleteComplete) {
flushThread.pause();
flushFromMem(wordHash);
flushFromAssortmentCluster(wordHash, -1);
int removed = backend.removeEntries(wordHash, urlHashes, deleteComplete);
flushThread.proceed();
return removed;
}
public int addEntries(plasmaWordIndexEntryContainer container, long updateTime, boolean highPriority) {
// this puts the entries into the cache, not into the assortment directly
int added = 0;
// check cache space
if (cache.size() > 0) try {
// pause to get space in the cache (while it is flushed)
long pausetime;
if (highPriority) {
if (cache.size() + 1000 >= this.maxWordsHigh) Thread.sleep(java.lang.Math.min(1000, cache.size() - this.maxWordsHigh + 1000));
pausetime = java.lang.Math.min(10, 2 * cache.size() / (maxWordsHigh + 1));
} else {
if (cache.size() + 1000 >= this.maxWordsLow) Thread.sleep(java.lang.Math.min(1000, cache.size() - this.maxWordsLow + 1000));
pausetime = java.lang.Math.min(10, 2 * cache.size() / (maxWordsLow + 1));
}
// slow down if we reach cache limit
Thread.sleep(pausetime);
} catch (InterruptedException e) {}
//serverLog.logDebug("PLASMA INDEXING", "addEntryToIndexMem: cache.size=" + cache.size() + "; hashScore.size=" + hashScore.size());
// put new words into cache
String wordHash = container.wordHash();
synchronized (cache) {
// stop flushing now for one moment
flushThread.pause();
// put container into cache
plasmaWordIndexEntryContainer entries = (plasmaWordIndexEntryContainer) cache.get(wordHash); // null pointer exception? wordhash != null! must be cache==null
if (entries == null) entries = new plasmaWordIndexEntryContainer(wordHash);
added = entries.add(container);
if (added > 0) {
cache.put(wordHash, entries);
hashScore.addScore(wordHash, added);
hashDate.setScore(wordHash, intTime(updateTime));
}
entries = null;
// resume flushing
flushThread.proceed();
}
//System.out.println("DEBUG: cache = " + cache.toString());
return added;
}
private void addEntry(String wordHash, plasmaWordIndexEntry newEntry, long updateTime) {
flushThread.pause();
plasmaWordIndexEntryContainer container = (plasmaWordIndexEntryContainer) cache.get(wordHash);
if (container == null) container = new plasmaWordIndexEntryContainer(wordHash);
plasmaWordIndexEntry[] entries = new plasmaWordIndexEntry[]{newEntry};
if (container.add(entries, updateTime) > 0) {
cache.put(wordHash, container);
hashScore.incScore(wordHash);
hashDate.setScore(wordHash, intTime(updateTime));
}
entries = null;
container = null;
flushThread.proceed();
}
public void close(int waitingSeconds) {
// stop permanent flushing
flushThread.terminate();
try {flushThread.join(5000);} catch (InterruptedException e) {}
// close cluster
assortmentCluster.close();
try {
dump(waitingSeconds);
} catch (IOException e){
log.logSevere("unable to dump cache: " + e.getMessage(), e);
}
}
public int migrateWords2Assortment(String wordhash) throws IOException {
// returns the number of entries that had been added to the assortments
// can be negative if some assortments have been moved to the backend
File db = plasmaWordIndexEntity.wordHash2path(databaseRoot, wordhash);
if (!(db.exists())) return 0;
plasmaWordIndexEntity entity = null;
try {
entity = new plasmaWordIndexEntity(databaseRoot, wordhash, true);
int size = entity.size();
if (size > assortmentCluster.clusterCapacity) {
// this will be too big to integrate it
entity.close(); entity = null;
return 0;
} else {
// take out all words from the assortment to see if it fits
// together with the extracted assortment
plasmaWordIndexEntryContainer container = assortmentCluster.removeFromAll(wordhash, -1);
if (size + container.size() > assortmentCluster.clusterCapacity) {
// this will also be too big to integrate, add to entity
entity.addEntries(container);
entity.close(); entity = null;
return -container.size();
} else {
// the combined container will fit, read the container
try {
Iterator entries = entity.elements(true);
plasmaWordIndexEntry entry;
while (entries.hasNext()) {
entry = (plasmaWordIndexEntry) entries.next();
System.out.println("ENTRY = " + entry.getUrlHash());
container.add(new plasmaWordIndexEntry[]{entry}, System.currentTimeMillis());
}
// we have read all elements, now delete the entity
entity.deleteComplete();
entity.close(); entity = null;
// integrate the container into the assortments; this will work
assortmentCluster.storeTry(wordhash, container);
return size;
} catch (kelondroException e) {
// database corrupted, we simply give up the database and delete it
try {entity.close();} catch (Exception ee) {} entity = null;
try {db.delete();} catch (Exception ee) {}
return 0;
}
}
}
} finally {
if (entity != null) try {entity.close();}catch(Exception e){}
}
}
}