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

// 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.net.URL;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashSet;
import java.util.Iterator;
import de.anomic.kelondro.kelondroException;
import de.anomic.kelondro.kelondroRecords;
import de.anomic.kelondro.kelondroStack;
import de.anomic.kelondro.kelondroTree;
import de.anomic.server.serverCodings;
import de.anomic.server.logging.serverLog;
import de.anomic.tools.bitfield;

public class plasmaCrawlNURL extends plasmaURL {

    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

    /**
     * column length definition for the {@link plasmaURL#urlHashCache} DB
     */
    public static final int[] ce = {
            urlHashLength,               // the url hash
            urlHashLength,               // initiator
            urlStringLength,             // the url as string
            urlHashLength,               // the url's referrer hash
            urlNameLength,               // the name of the url, from anchor tag <a>name</a>
            urlDateLength,               // the time when the url was first time appeared
            urlCrawlProfileHandleLength, // the name of the prefetch profile handle
            urlCrawlDepthLength,         // the prefetch depth so far, starts at 0
            urlParentBranchesLength,     // number of anchors of the parent
            urlForkFactorLength,         // sum of anchors of all ancestors
            urlFlagLength,               // extra space
            urlHandleLength              // extra handle
        };    
        
    private final plasmaCrawlBalancer coreStack;      // links found by crawling to depth-1
    private final plasmaCrawlBalancer limitStack;     // links found by crawling at target depth
    private final plasmaCrawlBalancer overhangStack;  // links found by crawling at depth+1
    private final plasmaCrawlBalancer remoteStack;    // links from remote crawl orders
    private kelondroStack imageStack;     // links pointing to image resources
    private kelondroStack movieStack;     // links pointing to movie resources
    private kelondroStack musicStack;     // links pointing to music resources

    private final HashSet stackIndex;           // to find out if a specific link is already on any stack
    private File cacheStacksPath;
    private int bufferkb;
    
    public plasmaCrawlNURL(File cacheStacksPath, int bufferkb) throws IOException {
        super();
        this.cacheStacksPath = cacheStacksPath;
        this.bufferkb = bufferkb;
        
        // create a stack for newly entered entries
        if (!(cacheStacksPath.exists())) cacheStacksPath.mkdir(); // make the path

        openHashCache();

        File coreStackFile = new File(cacheStacksPath, "urlNoticeLocal0.stack");
        File limitStackFile = new File(cacheStacksPath, "urlNoticeLimit0.stack");
        File overhangStackFile = new File(cacheStacksPath, "urlNoticeOverhang0.stack");
        File remoteStackFile = new File(cacheStacksPath, "urlNoticeRemote0.stack");
        File imageStackFile = new File(cacheStacksPath, "urlNoticeImage0.stack");
        File movieStackFile = new File(cacheStacksPath, "urlNoticeMovie0.stack");
        File musicStackFile = new File(cacheStacksPath, "urlNoticeMusic0.stack");
        coreStack = new plasmaCrawlBalancer(coreStackFile, 0);
        limitStack = new plasmaCrawlBalancer(limitStackFile, 0);
        overhangStack = new plasmaCrawlBalancer(overhangStackFile, 0);
        remoteStack = new plasmaCrawlBalancer(remoteStackFile, 0);
        if (imageStackFile.exists()) imageStack = new kelondroStack(imageStackFile, 0); else imageStack = new kelondroStack(imageStackFile, 0, new int[] {plasmaURL.urlHashLength});
        if (movieStackFile.exists()) movieStack = new kelondroStack(movieStackFile, 0); else movieStack = new kelondroStack(movieStackFile, 0, new int[] {plasmaURL.urlHashLength});
        if (musicStackFile.exists()) musicStack = new kelondroStack(musicStackFile, 0); else musicStack = new kelondroStack(musicStackFile, 0, new int[] {plasmaURL.urlHashLength});

        // init stack Index
        stackIndex = new HashSet();
        new initStackIndex().start();
    }
    
    private void openHashCache() throws IOException {
        File cacheFile = new File(cacheStacksPath, "urlNotice1.db");
        if (cacheFile.exists()) {
            // open existing cache
            urlHashCache = new kelondroTree(cacheFile, bufferkb * 0x400);
        } else {
            // create new cache
            cacheFile.getParentFile().mkdirs();
            urlHashCache = new kelondroTree(cacheFile, bufferkb * 0x400, ce);
        }
    }
    
    private void resetHashCache() throws IOException {
        if (urlHashCache != null) {
            try {urlHashCache.close();} catch (IOException e) {}
            urlHashCache = null;
            File cacheFile = new File(cacheStacksPath, "urlNotice1.db");
            cacheFile.delete();
        }
        openHashCache();
    }
    
    public void close() {
        coreStack.close();
        try {
            limitStack.close();
            overhangStack.close();
            remoteStack.close();
            imageStack.close();
            movieStack.close();
            musicStack.close();
        } catch (IOException e) {}
        try { super.close(); } catch (IOException e) {}
    }

    public class initStackIndex extends Thread {
        public void run() {
            Iterator i;
            try {
                try { i =     coreStack.iterator(); while (i.hasNext()) stackIndex.add(new String((byte[]) i.next()));} catch (Exception e) {coreStack.reset();}
                try { i =    limitStack.iterator(); while (i.hasNext()) stackIndex.add(new String((byte[]) i.next()));} catch (Exception e) {limitStack.reset();}
                try { i = overhangStack.iterator(); while (i.hasNext()) stackIndex.add(new String((byte[]) i.next()));} catch (Exception e) {overhangStack.reset();}
                try { i =   remoteStack.iterator(); while (i.hasNext()) stackIndex.add(new String((byte[]) i.next()));} catch (Exception e) {remoteStack.reset();}
                try { i =    imageStack.iterator(); while (i.hasNext()) stackIndex.add(new String(((kelondroRecords.Node) i.next()).getKey()));} catch (Exception e) {imageStack = kelondroStack.reset(imageStack);}
                try { i =    movieStack.iterator(); while (i.hasNext()) stackIndex.add(new String(((kelondroRecords.Node) i.next()).getKey()));} catch (Exception e) {movieStack = kelondroStack.reset(movieStack);}
                try { i =    musicStack.iterator(); while (i.hasNext()) stackIndex.add(new String(((kelondroRecords.Node) i.next()).getKey()));} catch (Exception e) {musicStack = kelondroStack.reset(musicStack);}
            } catch (IOException e) {}
        }
    }

    private static String normalizeHost(String host) {
        if (host.length() > urlHostLength) host = host.substring(0, urlHostLength);
        host = host.toLowerCase();
        while (host.length() < urlHostLength) host = host + " ";
        return host;
    }

    private static String normalizeHandle(int h) {
        String d = Integer.toHexString(h);
        while (d.length() < urlHandleLength) d = "0" + d;
        return d;
    }

    public int stackSize() {
        // this does not count the overhang stack size
        return coreStack.size()  + limitStack.size() + remoteStack.size();
    }

    public int stackSize(int stackType) {
        switch (stackType) {
            case STACK_TYPE_CORE:     return coreStack.size();
            case STACK_TYPE_LIMIT:    return limitStack.size();
            case STACK_TYPE_OVERHANG: return overhangStack.size();
            case STACK_TYPE_REMOTE:   return remoteStack.size();
            case STACK_TYPE_IMAGE:    return imageStack.size();
            case STACK_TYPE_MOVIE:    return movieStack.size();
            case STACK_TYPE_MUSIC:    return musicStack.size();
            default: return -1;
        }
    }

    public boolean existsInStack(String urlhash) {
        return stackIndex.contains(urlhash);
    }

    public synchronized Entry newEntry(String initiator, URL url, Date loaddate,
                                       String referrer, String name, String profile,
                                       int depth, int anchors, int forkfactor, int stackMode) {
        Entry e = new Entry(initiator, url, referrer, name, loaddate,
                            profile, depth, anchors, forkfactor);
        push(stackMode, url.getHost(), e.hash);
        return e;
    }

    private void push(int stackType, String domain, String hash) {
        try {
            switch (stackType) {
                case STACK_TYPE_CORE:     coreStack.add(domain, hash.getBytes()); break;
                case STACK_TYPE_LIMIT:    limitStack.add(domain, hash.getBytes()); break;
                case STACK_TYPE_OVERHANG: overhangStack.add(domain, hash.getBytes()); break;
                case STACK_TYPE_REMOTE:   remoteStack.add(domain, hash.getBytes()); break;
                case STACK_TYPE_IMAGE:    imageStack.push(new byte[][] {hash.getBytes()}); break;
                case STACK_TYPE_MOVIE:    movieStack.push(new byte[][] {hash.getBytes()}); break;
                case STACK_TYPE_MUSIC:    musicStack.push(new byte[][] {hash.getBytes()}); break;
                default: break;
            }
            stackIndex.add(hash);
        } catch (IOException er) {}
    }

    public Entry[] 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_OVERHANG: return top(overhangStack, count);
            case STACK_TYPE_REMOTE:   return top(remoteStack, count);
            case STACK_TYPE_IMAGE:    return top(imageStack, count);
            case STACK_TYPE_MOVIE:    return top(movieStack, count);
            case STACK_TYPE_MUSIC:    return top(musicStack, count);
            default: return null;
        }
    }

    public Entry pop(int stackType) {
        switch (stackType) {
            case STACK_TYPE_CORE:     return pop(coreStack);
            case STACK_TYPE_LIMIT:    return pop(limitStack);
            case STACK_TYPE_OVERHANG: return pop(overhangStack);
            case STACK_TYPE_REMOTE:   return pop(remoteStack);
            case STACK_TYPE_IMAGE:    return pop(imageStack);
            case STACK_TYPE_MOVIE:    return pop(movieStack);
            case STACK_TYPE_MUSIC:    return pop(musicStack);
            default: return null;
        }
    }

    public void shift(int fromStack, int toStack) throws IOException {
        Entry entry = pop(fromStack);
        if (entry.url() == null) return;
        push(toStack, entry.url.getHost(), entry.hash());
    }

    public void clear(int stackType) {
        try {
            switch (stackType) {
                case STACK_TYPE_CORE:     coreStack.clear(); break;
                case STACK_TYPE_LIMIT:    limitStack.clear(); break;
                case STACK_TYPE_OVERHANG: overhangStack.clear(); break;
                case STACK_TYPE_REMOTE:   remoteStack.clear(); break;
                case STACK_TYPE_IMAGE:    imageStack.clear(); break;
                case STACK_TYPE_MOVIE:    movieStack.clear(); break;
                case STACK_TYPE_MUSIC:    musicStack.clear(); break;
                default: return;
            }
        } catch (IOException e) {}
    }

    private Entry pop(kelondroStack stack) {
        // this is a filo - pop
        try {
            if (stack.size() > 0) {
                Entry e = new Entry(new String(stack.pop()[0]));
                stackIndex.remove(e.hash);
                return e;
            } else {
                return null;
            }
        } catch (IOException e) {
            return null;
        }
    }

    private Entry pop(plasmaCrawlBalancer balancer) {
        // this is a filo - pop
        try {
            if (balancer.size() > 0) {
                Entry e = new Entry(new String((byte[]) balancer.get()[1]));
                stackIndex.remove(e.hash);
                return e;
            } else {
                return null;
            }
        } catch (IOException e) {
            return null;
        }
    }

    private Entry[] top(kelondroStack stack, int count) {
        // this is a filo - top
        if (count > stack.size()) count = stack.size();
        ArrayList list = new ArrayList(count);
        try {
            for (int i = 0; i < count; i++) {
                byte[] hash = stack.top(i)[0];
                if (hash == null) continue;
                list.add(new Entry(new String(hash)));
            }
            return (Entry[])list.toArray(new Entry[list.size()]);
        } catch (IOException e) {
            return null;
        }
    }

    private Entry[] top(plasmaCrawlBalancer balancer, int count) {
        // this is a filo - top
        if (count > balancer.size()) count = balancer.size();
        ArrayList list = new ArrayList(count);
        try {
            for (int i = 0; i < count; i++) {
                byte[] hash = balancer.top(i);
                if (hash == null) continue;
                list.add(new Entry(new String(hash)));
            }
            return (Entry[])list.toArray(new Entry[list.size()]);
        } catch (IOException e) {
            return null;
        }
    }

    public synchronized Entry getEntry(String hash) {
        return new Entry(hash);
    }

    public synchronized void remove(String hash) {
        try {
            urlHashCache.remove(hash.getBytes());
        } catch (IOException e) {}
    }

    public class Entry {
        private String   initiator;     // the initiator hash, is NULL or "" if it is the own proxy;
                                        // if this is generated by a crawl, the own peer hash in entered
        private String   hash;          // the url's hash
        private String   referrer;      // the url's referrer hash
        private URL      url;           // the url as string
        private String   name;          // the name of the url, from anchor tag <a>name</a>     
        private Date     loaddate;      // the time when the url was first time appeared
        private String   profileHandle; // the name of the prefetch profile
        private int      depth;         // the prefetch depth so far, starts at 0
        private int      anchors;       // number of anchors of the parent
        private int      forkfactor;    // sum of anchors of all ancestors
        private bitfield flags;
        private int      handle;

        public Entry(String initiator, 
                     URL url, 
                     String referrer, 
                     String name, 
                     Date loaddate, 
                     String profileHandle,
                     int depth, 
                     int anchors, 
                     int forkfactor
        ) {
            // create new entry and store it into database
            this.hash          = urlHash(url);
            this.initiator     = initiator;
            this.url           = url;
            this.referrer      = (referrer == null) ? dummyHash : referrer;
            this.name          = (name == null) ? "" : name;
            this.loaddate      = (loaddate == null) ? new Date() : loaddate;
            this.profileHandle = profileHandle; // must not be null
            this.depth         = depth;
            this.anchors       = anchors;
            this.forkfactor    = forkfactor;
            this.flags         = new bitfield(urlFlagLength);
            this.handle        = 0;
            store();
        }

        public String toString() {
            StringBuffer str = new StringBuffer();
            str.append("hash: ").append(hash==null ? "null" : hash).append(" | ")
               .append("initiator: ").append(initiator==null?"null":initiator).append(" | ")
               .append("url: ").append(url==null?"null":url.toString()).append(" | ")
               .append("referrer: ").append((referrer == null) ? dummyHash : referrer).append(" | ")
               .append("name: ").append((name == null) ? "null" : name).append(" | ")
               .append("loaddate: ").append((loaddate == null) ? new Date() : loaddate).append(" | ")
               .append("profile: ").append(profileHandle==null?"null":profileHandle).append(" | ")
               .append("depth: ").append(Integer.toString(depth)).append(" | ")
               .append("forkfactor: ").append(Integer.toString(forkfactor)).append(" | ")
               .append("flags: ").append((flags==null) ? "null" : flags.toString());
               return str.toString();
        }

        public Entry(String hash) {
            // generates an plasmaNURLEntry using the url hash
            // to speed up the access, the url-hashes are buffered
            // in the hash cache.
            // we have two options to find the url:
            // - look into the hash cache
            // - look into the filed properties
            // if the url cannot be found, this returns null
            this.hash = hash;
            try {
                byte[][] entry = urlHashCache.get(hash.getBytes());
                if (entry != null) {
                    this.initiator     = new String(entry[1]);
                    this.url           = new URL(new String(entry[2]).trim());
                    this.referrer      = (entry[3]==null) ? dummyHash : new String(entry[3]);
                    this.name          = (entry[4] == null) ? "" : new String(entry[4]).trim();
                    this.loaddate      = new Date(86400000 * serverCodings.enhancedCoder.decodeBase64Long(new String(entry[5])));
                    this.profileHandle = (entry[6] == null) ? null : new String(entry[6]).trim();
                    this.depth         = (int) serverCodings.enhancedCoder.decodeBase64Long(new String(entry[7]));
                    this.anchors       = (int) serverCodings.enhancedCoder.decodeBase64Long(new String(entry[8]));
                    this.forkfactor    = (int) serverCodings.enhancedCoder.decodeBase64Long(new String(entry[9]));
                    this.flags         = new bitfield(entry[10]);
                    this.handle        = Integer.parseInt(new String(entry[11]));
                    return;
                } else {
                    // show that we found nothing
                    this.url = null;
                }
            } catch (Exception e) {
            }
        }

        private void store() {
            // stores the values from the object variables into the database
            String loaddatestr = serverCodings.enhancedCoder.encodeBase64Long(loaddate.getTime() / 86400000, urlDateLength);
            // store the hash in the hash cache
            try {
                // even if the entry exists, we simply overwrite it
                byte[][] entry = new byte[][] { 
                    this.hash.getBytes(),
                    (initiator == null) ? "".getBytes() : this.initiator.getBytes(),
                    this.url.toString().getBytes(),
                    this.referrer.getBytes(),
                    this.name.getBytes(),
                    loaddatestr.getBytes(),
                    (this.profileHandle == null) ? null : this.profileHandle.getBytes(),
                    serverCodings.enhancedCoder.encodeBase64Long(this.depth, urlCrawlDepthLength).getBytes(),
                    serverCodings.enhancedCoder.encodeBase64Long(this.anchors, urlParentBranchesLength).getBytes(),
                    serverCodings.enhancedCoder.encodeBase64Long(this.forkfactor, urlForkFactorLength).getBytes(),
                    this.flags.getBytes(),
                    normalizeHandle(this.handle).getBytes()
                };
                urlHashCache.put(entry);
            } catch (IOException e) {
                serverLog.logSevere("PLASMA", "INTERNAL ERROR AT plasmaNURL:store:" + e.toString() + ", resetting NURL-DB");
                try {
                    resetHashCache();
                } catch (IOException ee) {
                    serverLog.logSevere("PLASMA", "INTERNAL ERROR AT plasmaNURL:store:" + e.toString() + ", reset of NURL-DB failed");
                    System.exit(0); // this is REALLY severe
                }
            } catch (kelondroException e) {
                serverLog.logSevere("PLASMA", "plasmaCrawlNURL.store failed: " + e.toString() + ", resetting NURL-DB");
                try {
                    resetHashCache();
                } catch (IOException ee) {
                    serverLog.logSevere("PLASMA", "INTERNAL ERROR AT plasmaNURL:store:" + e.toString() + ", reset of NURL-DB failed");
                    System.exit(0); // this is REALLY severe
                }
            }
        }

        /**
         * 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
         */
        public String hash() {
            return this.hash;
        }

        public String initiator() {
            if (initiator == null) return null;
            if (initiator.length() == 0) return null; 
            return initiator;
        }

        public boolean proxy() {
            return (initiator() == null);
        }

        public String referrerHash() {
            return this.referrer;
        }

        public URL url() {
            return url;
        }

        public Date loaddate() {
            return loaddate;
        }

        public String name() {
            // return the creator's hash
            return name;
        }

        public int depth() {
            return depth;
        }

        public String profileHandle() {
            return profileHandle;
        }
    }

    /*
    public class kenum implements Enumeration {
    // enumerates entry elements
    kelondroTree.rowIterator i;
    public kenum(boolean up, boolean rotating) throws IOException {
            i = urlHashCache.rows(up, rotating);
        }
    public boolean hasMoreElements() {
            return i.hasNext();
        }
    public Object nextElement() {
            return new entry(new String(((byte[][]) i.next())[0]));
        }
    }
    public Enumeration elements(boolean up, boolean rotating) throws IOException {
    // enumerates entry elements
    return new kenum(up, rotating);
    }
    */
}