// plasmaNURL.java
// -----------------------
// part of YaCy
// (C) by Michael Peter Christen; mc@anomic.de
// 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
//
// 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.
// NURL - noticed (known but not loaded) URL's
package de.anomic.plasma;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
import de.anomic.server.logging.serverLog;
public class plasmaCrawlNURL {
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
private static final long minimumLocalDelta = 0; // the minimum time difference between access of the same local domain
private static final long minimumGlobalDelta = 333; // the minimum time difference between access of the same global domain
private static final long maximumDomAge = 60000; // the maximum age of a domain until it is used for another crawl attempt
private plasmaCrawlBalancer coreStack; // links found by crawling to depth-1
private plasmaCrawlBalancer limitStack; // links found by crawling at target depth
private plasmaCrawlBalancer remoteStack; // links from remote crawl orders
//private final plasmaCrawlBalancer overhangStack; // links found by crawling at depth+1
//private kelondroStack imageStack; // links pointing to image resources
//private kelondroStack movieStack; // links pointing to movie resources
//private kelondroStack musicStack; // links pointing to music resources
public plasmaCrawlNURL(File cachePath) {
super();
coreStack = new plasmaCrawlBalancer(cachePath, "urlNoticeCoreStack", false);
limitStack = new plasmaCrawlBalancer(cachePath, "urlNoticeLimitStack", false);
//overhangStack = new plasmaCrawlBalancer(overhangStackFile);
remoteStack = new plasmaCrawlBalancer(cachePath, "urlNoticeRemoteStack", false);
}
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;
}
}
public void finalize() {
if ((coreStack != null) || (limitStack != null) || (remoteStack != null)) {
serverLog.logWarning("plasmaCrawlNURL", "NURL stack closed by finalizer");
close();
}
}
public boolean notEmpty() {
return coreStack.notEmpty() || limitStack.notEmpty() || remoteStack.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(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(String urlhash) {
return
coreStack.has(urlhash) ||
limitStack.has(urlhash) ||
//overhangStack.has(urlhash) ||
remoteStack.has(urlhash);
}
public void push(int stackType, plasmaCrawlEntry 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 (IOException er) {}
}
public plasmaCrawlEntry get(String urlhash) {
plasmaCrawlEntry entry = null;
try {if ((entry = coreStack.get(urlhash)) != null) return entry;} catch (IOException e) {}
try {if ((entry = limitStack.get(urlhash)) != null) return entry;} catch (IOException e) {}
try {if ((entry = remoteStack.get(urlhash)) != null) return entry;} catch (IOException e) {}
return null;
}
public plasmaCrawlEntry removeByURLHash(String urlhash) {
plasmaCrawlEntry entry = null;
try {if ((entry = coreStack.remove(urlhash)) != null) return entry;} catch (IOException e) {}
try {if ((entry = limitStack.remove(urlhash)) != null) return entry;} catch (IOException e) {}
try {if ((entry = remoteStack.remove(urlhash)) != null) return entry;} catch (IOException e) {}
return null;
}
public int removeByProfileHandle(String handle) {
int removed = 0;
try {removed += coreStack.removeAllByProfileHandle(handle);} catch (IOException e) {}
try {removed += limitStack.removeAllByProfileHandle(handle);} catch (IOException e) {}
try {removed += remoteStack.removeAllByProfileHandle(handle);} catch (IOException e) {}
return removed;
}
public plasmaCrawlEntry[] top(int stackType, 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 plasmaCrawlEntry pop(int stackType, boolean delay) throws IOException {
switch (stackType) {
case STACK_TYPE_CORE: return pop(coreStack, delay);
case STACK_TYPE_LIMIT: return pop(limitStack, delay);
case STACK_TYPE_REMOTE: return pop(remoteStack, delay);
default: return null;
}
}
public void shift(int fromStack, int toStack) {
try {
plasmaCrawlEntry entry = pop(fromStack, false);
if (entry != null) push(toStack, entry);
} catch (IOException e) {
return;
}
}
public void clear(int 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 plasmaCrawlEntry pop(plasmaCrawlBalancer balancer, boolean delay) throws IOException {
// this is a filo - pop
int s;
plasmaCrawlEntry entry;
synchronized (balancer) {
while ((s = balancer.size()) > 0) {
entry = balancer.pop((delay) ? minimumLocalDelta : 0, (delay) ? minimumGlobalDelta : 0, maximumDomAge);
if (entry == null) {
if (s > balancer.size()) continue;
int aftersize = balancer.size();
balancer.clear(); // the balancer is broken and cannot shrink
throw new IOException("entry is null, balancer cannot shrink (bevore pop = " + s + ", after pop = " + aftersize + "); reset of balancer");
}
return entry;
}
}
throw new IOException("balancer stack is empty");
}
private plasmaCrawlEntry[] top(plasmaCrawlBalancer balancer, int count) {
// this is a filo - top
if (count > balancer.size()) count = balancer.size();
ArrayList<plasmaCrawlEntry> list = new ArrayList<plasmaCrawlEntry>(count);
for (int i = 0; i < count; i++) {
try {
plasmaCrawlEntry entry = balancer.top(i);
if (entry == null) break;
list.add(entry);
} catch (IOException e) {
break;
}
}
return (plasmaCrawlEntry[]) list.toArray(new plasmaCrawlEntry[list.size()]);
}
public Iterator<plasmaCrawlEntry> iterator(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 (IOException e) {
return new HashSet<plasmaCrawlEntry>().iterator();
}
}
}