// plasmaCrawlZURL.java
// (C) 2007 by Michael Peter Christen; mc@yacy.net, Frankfurt a. M., Germany
// first published 15.03.2007 on http://www.anomic.de
//
// This is a part of YaCy, a peer-to-peer based web search engine
//
// $LastChangedDate: 2011-05-27 10:24:54 +0200 (Fr, 27. Mai 2011) $
// $LastChangedRevision: 7746 $
// $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.crawler;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Date;
import java.util.Iterator;
import java.util.concurrent.ConcurrentLinkedQueue;
import net.yacy.cora.document.ASCII;
import net.yacy.cora.document.UTF8;
import net.yacy.cora.services.federated.solr.SolrChardingConnector;
import net.yacy.kelondro.data.meta.DigestURI;
import net.yacy.kelondro.data.word.Word;
import net.yacy.kelondro.index.Index;
import net.yacy.kelondro.index.Row;
import net.yacy.kelondro.index.RowSet;
import net.yacy.kelondro.index.RowSpaceExceededException;
import net.yacy.kelondro.logging.Log;
import net.yacy.kelondro.order.Base64Order;
import net.yacy.kelondro.table.SplitTable;
import net.yacy.kelondro.table.Table;
import net.yacy.kelondro.util.FileUtils;
import de.anomic.crawler.retrieval.Request;
public class ZURL implements Iterable<ZURL.Entry> {
private static final int EcoFSBufferSize = 2000;
private static final int maxStackSize = 1000;
public enum FailCategory {
// TEMPORARY categories are such failure cases that should be tried again
// FINAL categories are such failure cases that are final and should not be tried again
TEMPORARY_NETWORK_FAILURE, // an entity could not been loaded
FINAL_PROCESS_CONTEXT, // because of a processing context we do not want that url again (i.e. remote crawling)
FINAL_LOAD_CONTEXT, // the crawler configuration does not want to load the entity
FINAL_ROBOTS_RULE; // a remote server denies indexing or loading
}
private final static Row rowdef = new Row(
"String urlhash-" + Word.commonHashLength + ", " + // the url's hash
"String executor-" + Word.commonHashLength + ", " + // the crawling executor
"Cardinal workdate-8 {b256}, " + // the time when the url was last time tried to load
"Cardinal workcount-4 {b256}, " + // number of load retries
"String anycause-132, " + // string describing load failure
"byte[] entry-" + Request.rowdef.objectsize, // extra space
Base64Order.enhancedCoder
);
// the class object
private Index urlIndex;
private final ConcurrentLinkedQueue<byte[]> stack;
private final SolrChardingConnector solrConnector;
public ZURL(
final SolrChardingConnector solrConnector,
final File cachePath,
final String tablename,
final boolean startWithEmptyFile,
final boolean useTailCache,
final boolean exceed134217727) {
this.solrConnector = solrConnector;
// creates a new ZURL in a file
cachePath.mkdirs();
final File f = new File(cachePath, tablename);
if (startWithEmptyFile) {
if (f.exists()) {
if (f.isDirectory()) SplitTable.delete(cachePath, tablename); else FileUtils.deletedelete(f);
}
}
try {
this.urlIndex = new Table(f, rowdef, EcoFSBufferSize, 0, useTailCache, exceed134217727);
} catch (RowSpaceExceededException e) {
try {
this.urlIndex = new Table(f, rowdef, 0, 0, false, exceed134217727);
} catch (RowSpaceExceededException e1) {
Log.logException(e1);
}
}
//urlIndex = new kelondroFlexTable(cachePath, tablename, -1, rowdef, 0, true);
this.stack = new ConcurrentLinkedQueue<byte[]>();
}
public ZURL(final SolrChardingConnector solrConnector) {
this.solrConnector = solrConnector;
// creates a new ZUR in RAM
this.urlIndex = new RowSet(rowdef);
this.stack = new ConcurrentLinkedQueue<byte[]>();
}
public void clear() throws IOException {
if (urlIndex != null) urlIndex.clear();
if (stack != null) stack.clear();
}
public void close() {
try {this.clear();} catch (IOException e) {}
if (urlIndex != null) urlIndex.close();
}
public boolean remove(final byte[] hash) {
if (hash == null) return false;
//System.out.println("*** DEBUG ZURL " + this.urlIndex.filename() + " remove " + hash);
try {
urlIndex.delete(hash);
return true;
} catch (final IOException e) {
return false;
}
}
public void push(
final Request bentry,
final byte[] executor,
final Date workdate,
final int workcount,
final FailCategory failCategory,
String anycause,
int httpcode) {
// assert executor != null; // null == proxy !
if (exists(bentry.url().hash())) return; // don't insert double causes
if (anycause == null) anycause = "unknown";
String reason = anycause + ((httpcode >= 0) ? " (http return code = " + httpcode + ")" : "");
Entry entry = new Entry(bentry, executor, workdate, workcount, reason);
put(entry);
stack.add(entry.hash());
Log.logInfo("Rejected URL", bentry.url().toNormalform(false, false) + " - " + reason);
if (this.solrConnector != null && (failCategory == FailCategory.TEMPORARY_NETWORK_FAILURE || failCategory == FailCategory.FINAL_ROBOTS_RULE)) {
// send the error to solr
try {
this.solrConnector.err(bentry.url(), failCategory.name() + " " + reason, httpcode);
} catch (IOException e) {
Log.logWarning("SOLR", "failed to send error " + bentry.url().toNormalform(true, false) + " to solr: " + e.getMessage());
}
}
while (stack.size() > maxStackSize) stack.poll();
}
public Iterator<ZURL.Entry> iterator() {
return new EntryIterator();
}
public ArrayList<ZURL.Entry> list(int max) {
ArrayList<ZURL.Entry> l = new ArrayList<ZURL.Entry>();
DigestURI url;
for (ZURL.Entry entry: this) {
if (entry == null) continue;
url = entry.url();
if (url == null) continue;
l.add(entry);
if (max-- <= 0) l.remove(0);
}
return l;
}
private class EntryIterator implements Iterator<ZURL.Entry> {
private final Iterator<byte[]> hi;
public EntryIterator() {
this.hi = stack.iterator();
}
public boolean hasNext() {
return hi.hasNext();
}
public ZURL.Entry next() {
return get(hi.next());
}
public void remove() {
hi.remove();
}
}
public ZURL.Entry get(final byte[] urlhash) {
try {
if (urlIndex == null) return null;
// System.out.println("*** DEBUG ZURL " + this.urlIndex.filename() + " get " + urlhash);
final Row.Entry entry = urlIndex.get(urlhash);
if (entry == null) return null;
return new Entry(entry);
} catch (final IOException e) {
Log.logException(e);
return null;
}
}
/**
* private put (use push instead)
* @param entry
*/
private void put(Entry entry) {
// stores the values from the object variables into the database
if (entry.stored) return;
if (entry.bentry == null) return;
final Row.Entry newrow = rowdef.newEntry();
newrow.setCol(0, entry.bentry.url().hash());
newrow.setCol(1, entry.executor);
newrow.setCol(2, entry.workdate.getTime());
newrow.setCol(3, entry.workcount);
newrow.setCol(4, UTF8.getBytes(entry.anycause));
newrow.setCol(5, entry.bentry.toRow().bytes());
try {
if (urlIndex != null) urlIndex.put(newrow);
entry.stored = true;
} catch (final Exception e) {
Log.logException(e);
}
}
public boolean exists(final byte[] urlHash) {
return urlIndex.has(urlHash);
}
public void clearStack() {
stack.clear();
}
public int stackSize() {
return stack.size();
}
public class Entry {
Request bentry; // the balancer entry
private final byte[] executor; // the crawling executor
private final Date workdate; // the time when the url was last time tried to load
private final int workcount; // number of tryings
private final String anycause; // string describing reason for load fail
private boolean stored;
protected Entry(
final Request bentry,
final byte[] executor,
final Date workdate,
final int workcount,
final String anycause) {
// create new entry
assert bentry != null;
// assert executor != null; // null == proxy !
this.bentry = bentry;
this.executor = executor;
this.workdate = (workdate == null) ? new Date() : workdate;
this.workcount = workcount;
this.anycause = (anycause == null) ? "" : anycause;
stored = false;
}
protected Entry(final Row.Entry entry) throws IOException {
assert (entry != null);
this.executor = entry.getColBytes(1, true);
this.workdate = new Date(entry.getColLong(2));
this.workcount = (int) entry.getColLong(3);
this.anycause = entry.getColString(4);
this.bentry = new Request(Request.rowdef.newEntry(entry.getColBytes(5, false)));
assert (Base64Order.enhancedCoder.equal(entry.getPrimaryKeyBytes(), bentry.url().hash()));
this.stored = true;
return;
}
public DigestURI url() {
return this.bentry.url();
}
public byte[] initiator() {
return this.bentry.initiator();
}
public byte[] hash() {
// return a url-hash, based on the md5 algorithm
// the result is a String of 12 bytes within a 72-bit space
// (each byte has an 6-bit range)
// that should be enough for all web pages on the world
return this.bentry.url().hash();
}
public Date workdate() {
return workdate;
}
public byte[] executor() {
// return the creator's hash
return executor;
}
public String anycause() {
return anycause;
}
}
private class kiter implements Iterator<Entry> {
// enumerates entry elements
private Iterator<Row.Entry> i;
private boolean error = false;
private kiter(final boolean up, final String firstHash) throws IOException {
i = urlIndex.rows(up, (firstHash == null) ? null : ASCII.getBytes(firstHash));
error = false;
}
public boolean hasNext() {
if (error) return false;
return i.hasNext();
}
public Entry next() throws RuntimeException {
final Row.Entry e = i.next();
if (e == null) return null;
try {
return new Entry(e);
} catch (final IOException ex) {
throw new RuntimeException("error '" + ex.getMessage() + "' for hash " + e.getColString(0));
}
}
public void remove() {
i.remove();
}
}
public Iterator<Entry> entries(final boolean up, final String firstHash) throws IOException {
// enumerates entry elements
return new kiter(up, firstHash);
}
}