add bloom filter for scheduler #118

webmagic-core/src/main/java/us/codecraft/webmagic/scheduler/DuplicateRemovedScheduler.java

@@ -4,6 +4,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import us.codecraft.webmagic.Request;
 import us.codecraft.webmagic.Task;
+import us.codecraft.webmagic.scheduler.component.DuplicateRemover;
 
 /**
  * Remove duplicate urls and only push urls which are not duplicate.<br></br>
@@ -11,30 +12,29 @@ import us.codecraft.webmagic.Task;
  * @author code4crafer@gmail.com
  * @since 0.5.0
  */
-public abstract class DuplicatedRemoveScheduler implements Scheduler {
+public abstract class DuplicateRemovedScheduler implements Scheduler {
 
     protected Logger logger = LoggerFactory.getLogger(getClass());
 
+    private DuplicateRemover duplicatedRemover;
+
+    public DuplicateRemover getDuplicateRemover() {
+        return duplicatedRemover;
+    }
+
+    public void setDuplicateRemover(DuplicateRemover duplicatedRemover) {
+        this.duplicatedRemover = duplicatedRemover;
+    }
+
     @Override
     public void push(Request request, Task task) {
         logger.trace("get a candidate url {}", request.getUrl());
-        if (!isDuplicate(request, task) || shouldReserved(request)) {
+        if (!duplicatedRemover.isDuplicate(request, task) || shouldReserved(request)) {
             logger.debug("push to queue {}", request.getUrl());
             pushWhenNoDuplicate(request, task);
         }
     }
 
-    /**
-     * Reset duplicate check.
-     */
-    public abstract void resetDuplicateCheck(Task task);
-
-    /**
-     * @param request
-     * @return
-     */
-    protected abstract boolean isDuplicate(Request request, Task task);
-
     protected boolean shouldReserved(Request request) {
         return request.getExtra(Request.CYCLE_TRIED_TIMES) != null;
     }

webmagic-core/src/main/java/us/codecraft/webmagic/scheduler/PriorityScheduler.java

@@ -17,7 +17,7 @@ import java.util.concurrent.PriorityBlockingQueue;
  * @since 0.2.1
  */
 @ThreadSafe
-public class PriorityScheduler extends LocalDuplicatedRemoveScheduler {
+public class PriorityScheduler extends DuplicateRemovedScheduler implements MonitorableScheduler {
 
     public static final int INITIAL_CAPACITY = 5;
 
@@ -65,4 +65,9 @@ public class PriorityScheduler extends LocalDuplicatedRemoveScheduler {
     public int getLeftRequestsCount(Task task) {
         return noPriorityQueue.size();
     }
+
+    @Override
+    public int getTotalRequestsCount(Task task) {
+        return getDuplicateRemover().getTotalRequestsCount(task);
+    }
 }

webmagic-core/src/main/java/us/codecraft/webmagic/scheduler/QueueScheduler.java

@@ -16,7 +16,7 @@ import java.util.concurrent.LinkedBlockingQueue;
  * @since 0.1.0
  */
 @ThreadSafe
-public class QueueScheduler extends LocalDuplicatedRemoveScheduler {
+public class QueueScheduler extends DuplicateRemovedScheduler implements MonitorableScheduler {
 
     private BlockingQueue<Request> queue = new LinkedBlockingQueue<Request>();
 
@@ -34,4 +34,9 @@ public class QueueScheduler extends LocalDuplicatedRemoveScheduler {
     public int getLeftRequestsCount(Task task) {
         return queue.size();
     }
+
+    @Override
+    public int getTotalRequestsCount(Task task) {
+        return getDuplicateRemover().getTotalRequestsCount(task);
+    }
 }

webmagic-core/src/main/java/us/codecraft/webmagic/scheduler/component/BloomFilterDuplicateRemover.java

@@ -0,0 +1,61 @@
+package us.codecraft.webmagic.scheduler.component;
+
+import com.google.common.hash.BloomFilter;
+import com.google.common.hash.Funnels;
+import us.codecraft.webmagic.Request;
+import us.codecraft.webmagic.Task;
+
+import java.nio.charset.Charset;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * BloomFilterDuplicateRemover for huge number of urls.
+ *
+ * @author code4crafer@gmail.com
+ * @since 0.5.1
+ */
+public class BloomFilterDuplicateRemover implements DuplicateRemover {
+
+    private int expectedInsertions;
+
+    private double fpp;
+
+    private AtomicInteger counter;
+
+    public BloomFilterDuplicateRemover(int expectedInsertions) {
+        this(expectedInsertions, 0.03);
+    }
+
+    public BloomFilterDuplicateRemover(int expectedInsertions, double fpp) {
+        this.expectedInsertions = expectedInsertions;
+        this.fpp = fpp;
+        this.bloomFilter = rebuildBloomFilter();
+    }
+
+    protected BloomFilter<CharSequence> rebuildBloomFilter() {
+        counter = new AtomicInteger(0);
+        return BloomFilter.create(Funnels.stringFunnel(Charset.defaultCharset()), expectedInsertions, fpp);
+    }
+
+    private final BloomFilter<CharSequence> bloomFilter;
+
+    @Override
+    public boolean isDuplicate(Request request, Task task) {
+        boolean isDuplicate = bloomFilter.mightContain(request.getUrl());
+        if (!isDuplicate) {
+            bloomFilter.apply(request.getUrl());
+            counter.incrementAndGet();
+        }
+        return isDuplicate;
+    }
+
+    @Override
+    public void resetDuplicateCheck(Task task) {
+        rebuildBloomFilter();
+    }
+
+    @Override
+    public int getTotalRequestsCount(Task task) {
+        return counter.get();
+    }
+}

webmagic-core/src/main/java/us/codecraft/webmagic/scheduler/component/DuplicateRemover.java

@@ -0,0 +1,35 @@
+package us.codecraft.webmagic.scheduler.component;
+
+import us.codecraft.webmagic.Request;
+import us.codecraft.webmagic.Task;
+
+/**
+ * Remove duplicate requests.
+ * @author code4crafer@gmail.com
+ * @since 0.5.1
+ */
+public interface DuplicateRemover {
+    /**
+     *
+     * Check whether the request is duplicate.
+     *
+     * @param request
+     * @param task
+     * @return
+     */
+    public boolean isDuplicate(Request request, Task task);
+
+    /**
+     * Reset duplicate check.
+     * @param task
+     */
+    public void resetDuplicateCheck(Task task);
+
+    /**
+     * Get TotalRequestsCount for monitor.
+     * @param task
+     * @return
+     */
+    public int getTotalRequestsCount(Task task);
+
+}

webmagic-core/src/main/java/us/codecraft/webmagic/scheduler/component/HashSetDuplicateRemover.java

@@ -1,4 +1,4 @@
-package us.codecraft.webmagic.scheduler;
+package us.codecraft.webmagic.scheduler.component;
 
 import com.google.common.collect.Sets;
 import us.codecraft.webmagic.Request;
@@ -8,25 +8,22 @@ import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
 /**
- * Base Scheduler with duplicated urls removed by hash set.<br></br>
- *
- * @author code4crafter@gmail.com
- * @since 0.5.0
+ * @author code4crafer@gmail.com
  */
-public abstract class LocalDuplicatedRemoveScheduler extends DuplicatedRemoveScheduler implements MonitorableScheduler {
+public class HashSetDuplicateRemover implements DuplicateRemover {
 
     private Set<String> urls = Sets.newSetFromMap(new ConcurrentHashMap<String, Boolean>());
 
+    @Override
+    public boolean isDuplicate(Request request, Task task) {
+        return !urls.add(request.getUrl());
+    }
+
     @Override
     public void resetDuplicateCheck(Task task) {
         urls.clear();
     }
 
-    @Override
-    protected boolean isDuplicate(Request request, Task task) {
-        return !urls.add(request.getUrl());
-    }
-
     @Override
     public int getTotalRequestsCount(Task task) {
         return urls.size();

webmagic-core/src/main/java/us/codecraft/webmagic/scheduler/component/package.html

@@ -0,0 +1,5 @@
+<html>
+	<body>
+Component of scheduler.
+	</body>
+</html>

webmagic-core/src/test/java/us/codecraft/webmagic/scheduler/BloomFilterDuplicateRemoverTest.java

@@ -0,0 +1,27 @@
+package us.codecraft.webmagic.scheduler;
+
+import org.junit.Test;
+import us.codecraft.webmagic.Request;
+import us.codecraft.webmagic.scheduler.component.BloomFilterDuplicateRemover;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author code4crafer@gmail.com
+ */
+public class BloomFilterDuplicateRemoverTest {
+
+    @Test
+    public void testRemove() throws Exception {
+        BloomFilterDuplicateRemover bloomFilterDuplicateRemover = new BloomFilterDuplicateRemover(10);
+        boolean isDuplicate = bloomFilterDuplicateRemover.isDuplicate(new Request("a"), null);
+        assertThat(isDuplicate).isFalse();
+        isDuplicate = bloomFilterDuplicateRemover.isDuplicate(new Request("a"), null);
+        assertThat(isDuplicate);
+        isDuplicate = bloomFilterDuplicateRemover.isDuplicate(new Request("b"), null);
+        assertThat(isDuplicate).isFalse();
+        isDuplicate = bloomFilterDuplicateRemover.isDuplicate(new Request("b"), null);
+        assertThat(isDuplicate);
+
+    }
+}

webmagic-extension/src/main/java/us/codecraft/webmagic/scheduler/FileCacheQueueScheduler.java

@@ -2,8 +2,6 @@ package us.codecraft.webmagic.scheduler;
 
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang3.math.NumberUtils;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import us.codecraft.webmagic.Request;
 import us.codecraft.webmagic.Task;
 
@@ -23,9 +21,7 @@ import java.util.concurrent.atomic.AtomicInteger;
  * @author code4crafter@gmail.com <br>
  * @since 0.2.0
  */
-public class FileCacheQueueScheduler extends LocalDuplicatedRemoveScheduler {
-
-    private Logger logger = LoggerFactory.getLogger(getClass());
+public class FileCacheQueueScheduler extends DuplicateRemovedScheduler implements MonitorableScheduler {
 
     private String filePath = System.getProperty("java.io.tmpdir");
 
@@ -166,4 +162,9 @@ public class FileCacheQueueScheduler extends LocalDuplicatedRemoveScheduler {
     public int getLeftRequestsCount(Task task) {
         return queue.size();
     }
+
+    @Override
+    public int getTotalRequestsCount(Task task) {
+        return getDuplicateRemover().getTotalRequestsCount(task);
+    }
 }

webmagic-extension/src/main/java/us/codecraft/webmagic/scheduler/RedisScheduler.java

@@ -7,6 +7,7 @@ import redis.clients.jedis.JedisPool;
 import redis.clients.jedis.JedisPoolConfig;
 import us.codecraft.webmagic.Request;
 import us.codecraft.webmagic.Task;
+import us.codecraft.webmagic.scheduler.component.DuplicateRemover;
 
 /**
  * Use Redis as url scheduler for distributed crawlers.<br>
@@ -14,7 +15,7 @@ import us.codecraft.webmagic.Task;
  * @author code4crafter@gmail.com <br>
  * @since 0.2.0
  */
-public class RedisScheduler extends DuplicatedRemoveScheduler implements MonitorableScheduler {
+public class RedisScheduler extends DuplicateRemovedScheduler implements MonitorableScheduler, DuplicateRemover {
 
     private JedisPool pool;
 
@@ -43,7 +44,7 @@ public class RedisScheduler extends DuplicatedRemoveScheduler implements Monitor
     }
 
     @Override
-    protected boolean isDuplicate(Request request, Task task) {
+    public boolean isDuplicate(Request request, Task task) {
         Jedis jedis = pool.getResource();
         try {
             boolean isDuplicate = jedis.sismember(getSetKey(task), request.getUrl());