// plasmaNURL.java
// -----------------------
// part of YaCy
// (C) by Michael Peter Christen; mc@yacy.net
// first published on http://www.anomic.de
// Frankfurt, Germany, 2004
// last major change: 09.08.2004
//
// 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
// NURL - noticed (known but not loaded) URL's
package de.anomic.crawler;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
import de.anomic.kelondro.util.Log;
public class NoticedURL {
public static final int STACK_TYPE_NULL = 0; // do not stack
public static final int STACK_TYPE_CORE = 1; // put on local stack
public static final int STACK_TYPE_LIMIT = 2; // put on global stack
public static final int STACK_TYPE_OVERHANG = 3; // put on overhang stack; links that are known but not crawled
public static final int STACK_TYPE_REMOTE = 4; // put on remote-triggered stack
public static final int STACK_TYPE_IMAGE = 11; // put on image stack
public static final int STACK_TYPE_MOVIE = 12; // put on movie stack
public static final int STACK_TYPE_MUSIC = 13; // put on music stack
public static final long minimumLocalDeltaInit = 10; // the minimum time difference between access of the same local domain
public static final long minimumGlobalDeltaInit = 500; // the minimum time difference between access of the same global domain
private Balancer coreStack; // links found by crawling to depth-1
private Balancer limitStack; // links found by crawling at target depth
private Balancer remoteStack; // links from remote crawl orders
public NoticedURL(final File cachePath) {
this.coreStack = new Balancer(cachePath, "urlNoticeCoreStack", false, minimumLocalDeltaInit, minimumGlobalDeltaInit);
this.limitStack = new Balancer(cachePath, "urlNoticeLimitStack", false, minimumLocalDeltaInit, minimumGlobalDeltaInit);
//overhangStack = new plasmaCrawlBalancer(overhangStackFile);
this.remoteStack = new Balancer(cachePath, "urlNoticeRemoteStack", false, minimumLocalDeltaInit, minimumGlobalDeltaInit);
}
public long getMinimumLocalDelta() {
return this.coreStack.getMinimumLocalDelta();
}
public long getMinimumGlobalDelta() {
return this.coreStack.getMinimumGlobalDelta();
}
public void setMinimumDelta(final long minimumLocalDelta, final long minimumGlobalDelta) {
this.coreStack.setMinimumDelta(minimumLocalDelta, minimumGlobalDelta);
this.limitStack.setMinimumDelta(minimumLocalDelta, minimumGlobalDelta);
this.remoteStack.setMinimumDelta(minimumLocalDelta, minimumGlobalDelta);
}
public void clear() {
Log.logInfo("NoticedURL", "CLEARING ALL STACKS!");
coreStack.clear();
limitStack.clear();
remoteStack.clear();
}
public void close() {
if (coreStack != null) {
coreStack.close();
coreStack = null;
}
if (limitStack != null) {
limitStack.close();
limitStack = null;
}
//overhangStack.close();
if (remoteStack != null) {
remoteStack.close();
remoteStack = null;
}
}
protected void finalize() {
if ((coreStack != null) || (limitStack != null) || (remoteStack != null)) {
Log.logWarning("plasmaCrawlNURL", "NURL stack closed by finalizer");
close();
}
}
public boolean notEmpty() {
return coreStack.notEmpty() || limitStack.notEmpty() || remoteStack.notEmpty();
}
public boolean notEmptyLocal() {
return coreStack.notEmpty() || limitStack.notEmpty();
}
public int size() {
// this does not count the overhang stack size
return ((coreStack == null) ? 0 : coreStack.size()) + ((limitStack == null) ? 0 : limitStack.size()) + ((remoteStack == null) ? 0 : remoteStack.size());
}
public int stackSize(final int stackType) {
switch (stackType) {
case STACK_TYPE_CORE: return (coreStack == null) ? 0 : coreStack.size();
case STACK_TYPE_LIMIT: return (limitStack == null) ? 0 : limitStack.size();
case STACK_TYPE_OVERHANG: return 0;
case STACK_TYPE_REMOTE: return (remoteStack == null) ? 0 : remoteStack.size();
default: return -1;
}
}
public boolean existsInStack(final String urlhash) {
return
coreStack.has(urlhash) ||
limitStack.has(urlhash) ||
//overhangStack.has(urlhash) ||
remoteStack.has(urlhash);
}
public void push(final int stackType, final CrawlEntry entry) {
try {
switch (stackType) {
case STACK_TYPE_CORE:
coreStack.push(entry);
break;
case STACK_TYPE_LIMIT:
limitStack.push(entry);
break;
case STACK_TYPE_REMOTE:
remoteStack.push(entry);
break;
default: break;
}
} catch (final IOException er) {}
}
public CrawlEntry get(final String urlhash) {
CrawlEntry entry = null;
try {if ((entry = coreStack.get(urlhash)) != null) return entry;} catch (final IOException e) {}
try {if ((entry = limitStack.get(urlhash)) != null) return entry;} catch (final IOException e) {}
try {if ((entry = remoteStack.get(urlhash)) != null) return entry;} catch (final IOException e) {}
return null;
}
/**
* remove a CrawlEntry by a given hash. Usage of this method is not encouraged,
* because the underlying data structure (crawl stacks) cannot handle removals very good.
* @param urlhash
* @return true, if the entry was removed; false if not
*/
public boolean removeByURLHash(final String urlhash) {
final HashSet<String> urlHashes = new HashSet<String>();
urlHashes.add(urlhash);
try {return coreStack.remove(urlHashes) > 0;} catch (final IOException e) {}
try {return limitStack.remove(urlHashes) > 0;} catch (final IOException e) {}
try {return remoteStack.remove(urlHashes) > 0;} catch (final IOException e) {}
return false;
}
public int removeByProfileHandle(final String handle, final long timeout) {
int removed = 0;
try {removed += coreStack.removeAllByProfileHandle(handle, timeout);} catch (final IOException e) {}
try {removed += limitStack.removeAllByProfileHandle(handle, timeout);} catch (final IOException e) {}
try {removed += remoteStack.removeAllByProfileHandle(handle, timeout);} catch (final IOException e) {}
return removed;
}
public ArrayList<CrawlEntry> top(final int stackType, final int count) {
switch (stackType) {
case STACK_TYPE_CORE: return top(coreStack, count);
case STACK_TYPE_LIMIT: return top(limitStack, count);
case STACK_TYPE_REMOTE: return top(remoteStack, count);
default: return null;
}
}
public CrawlEntry pop(final int stackType, final boolean delay, CrawlProfile profile) throws IOException {
switch (stackType) {
case STACK_TYPE_CORE: return pop(coreStack, delay, profile);
case STACK_TYPE_LIMIT: return pop(limitStack, delay, profile);
case STACK_TYPE_REMOTE: return pop(remoteStack, delay, profile);
default: return null;
}
}
public void shift(final int fromStack, final int toStack, CrawlProfile profile) {
try {
final CrawlEntry entry = pop(fromStack, false, profile);
if (entry != null) push(toStack, entry);
} catch (final IOException e) {
return;
}
}
public void clear(final int stackType) {
Log.logInfo("NoticedURL", "CLEARING STACK " + stackType);
switch (stackType) {
case STACK_TYPE_CORE: coreStack.clear(); break;
case STACK_TYPE_LIMIT: limitStack.clear(); break;
case STACK_TYPE_REMOTE: remoteStack.clear(); break;
default: return;
}
}
private CrawlEntry pop(final Balancer balancer, final boolean delay, CrawlProfile profile) throws IOException {
// this is a filo - pop
int s;
CrawlEntry entry;
int errors = 0;
synchronized (balancer) {
while ((s = balancer.size()) > 0) {
entry = balancer.pop(delay, profile);
if (entry == null) {
if (s > balancer.size()) continue;
errors++;
if (errors < 100) continue;
final int aftersize = balancer.size();
balancer.clear(); // the balancer is broken and cannot shrink
Log.logWarning("BALANCER", "entry is null, balancer cannot shrink (bevore pop = " + s + ", after pop = " + aftersize + "); reset of balancer");
}
return entry;
}
}
return null;
}
private ArrayList<CrawlEntry> top(final Balancer balancer, int count) {
// this is a filo - top
if (count > balancer.size()) count = balancer.size();
ArrayList<CrawlEntry> list;
list = balancer.top(count);
return list;
}
public Iterator<CrawlEntry> iterator(final int stackType) {
// returns an iterator of plasmaCrawlBalancerEntry Objects
try {switch (stackType) {
case STACK_TYPE_CORE: return coreStack.iterator();
case STACK_TYPE_LIMIT: return limitStack.iterator();
case STACK_TYPE_REMOTE: return remoteStack.iterator();
default: return null;
}} catch (final IOException e) {
return new HashSet<CrawlEntry>().iterator();
}
}
}