Closes #222: full reindexing scalable + concurrent Lucene merges

docs-core/src/main/java/com/sismics/docs/core/dao/DocumentDao.java

@@ -46,12 +46,16 @@ public class DocumentDao {
     /**
      * Returns the list of all active documents.
      *
+     * @param offset Offset
+     * @param limit Limit
      * @return List of documents
      */
     @SuppressWarnings("unchecked")
-    public List<Document> findAll() {
+    public List<Document> findAll(int offset, int limit) {
         EntityManager em = ThreadLocalContext.get().getEntityManager();
         Query q = em.createQuery("select d from Document d where d.deleteDate is null");
+        q.setFirstResult(offset);
+        q.setMaxResults(limit);
         return q.getResultList();
     }
 

docs-core/src/main/java/com/sismics/docs/core/dao/FileDao.java

@@ -43,12 +43,16 @@ public class FileDao {
     /**
      * Returns the list of all files.
      *
+     * @param offset Offset
+     * @param limit Limit
      * @return List of files
      */
     @SuppressWarnings("unchecked")
-    public List<File> findAll() {
+    public List<File> findAll(int offset, int limit) {
         EntityManager em = ThreadLocalContext.get().getEntityManager();
         Query q = em.createQuery("select f from File f where f.deleteDate is null");
+        q.setFirstResult(offset);
+        q.setMaxResults(limit);
         return q.getResultList();
     }
     

docs-core/src/main/java/com/sismics/docs/core/listener/async/RebuildIndexAsyncListener.java

@@ -37,18 +37,31 @@ public class RebuildIndexAsyncListener {
             log.info("Rebuild index event: " + event.toString());
         }
 
-        // Fetch all documents and files
+        // Clear the index
+        AppContext.getInstance().getIndexingHandler().clearIndex();
+
+        // Index all documents
         TransactionUtil.handle(() -> {
-            // Fetch all documents
+            int offset = 0;
             DocumentDao documentDao = new DocumentDao();
-            List<Document> documentList = documentDao.findAll();
+            List<Document> documentList;
+            do {
+                documentList = documentDao.findAll(offset, 100);
+                AppContext.getInstance().getIndexingHandler().createDocuments(documentList);
+                offset += 100;
+            } while (documentList.size() > 0);
+        });
 
-            // Fetch all files
+        // Index all files
+        TransactionUtil.handle(() -> {
+            int offset = 0;
             FileDao fileDao = new FileDao();
-            List<File> fileList = fileDao.findAll();
+            List<File> fileList;
-
+            do {
-            // Rebuild index
+                fileList = fileDao.findAll(offset, 100);
-            AppContext.getInstance().getIndexingHandler().rebuildIndex(documentList, fileList);
+                AppContext.getInstance().getIndexingHandler().createFiles(fileList);
+                offset += 100;
+            } while (fileList.size() > 0);
         });
     }
 }

docs-core/src/main/java/com/sismics/docs/core/util/indexing/IndexingHandler.java

@@ -36,12 +36,23 @@ public interface IndexingHandler {
     void shutDown();
 
     /**
-     * Fully rebuild the index.
+     * Clear the index.
+     */
+    void clearIndex();
+
+    /**
+     * Index a list of documents.
      *
      * @param documentList All documents
+     */
+    void createDocuments(List<Document> documentList);
+
+    /**
+     * Index a list of files.
+     *
      * @param fileList All files
      */
-    void rebuildIndex(List<Document> documentList, List<File> fileList);
+    void createFiles(List<File> fileList);
 
     /**
      * Index a new document.

docs-core/src/main/java/com/sismics/docs/core/util/indexing/LuceneIndexingHandler.java

@@ -101,7 +101,7 @@ public class LuceneIndexingHandler implements IndexingHandler {
         // Create an index writer
         IndexWriterConfig config = new IndexWriterConfig(new StandardAnalyzer());
         config.setCommitOnClose(true);
-        config.setMergeScheduler(new SerialMergeScheduler());
+        config.setMergeScheduler(new ConcurrentMergeScheduler());
         indexWriter = new IndexWriter(directory, config);
 
         // Check index version and rebuild it if necessary
@@ -142,18 +142,23 @@ public class LuceneIndexingHandler implements IndexingHandler {
     }
 
     @Override
-    public void rebuildIndex(final List<Document> documentList, final List<File> fileList) {
+    public void clearIndex() {
-        handle(indexWriter -> {
+        handle(IndexWriter::deleteAll);
-            // Empty index
+    }
-            indexWriter.deleteAll();
 
-            // Add all documents
+    @Override
+    public void createDocuments(List<Document> documentList) {
+        handle(indexWriter -> {
             for (Document document : documentList) {
                 org.apache.lucene.document.Document luceneDocument = getDocumentFromDocument(document);
                 indexWriter.addDocument(luceneDocument);
             }
+        });
+    }
 
-            // Add all files
+    @Override
+    public void createFiles(List<File> fileList) {
+        handle(indexWriter -> {
             for (File file : fileList) {
                 org.apache.lucene.document.Document luceneDocument = getDocumentFromFile(file);
                 indexWriter.addDocument(luceneDocument);

docs-core/src/main/java/com/sismics/docs/core/util/jpa/PaginatedLists.java

@@ -36,7 +36,7 @@ public class PaginatedLists {
         if (pageSize > MAX_PAGE_SIZE) {
             pageSize = MAX_PAGE_SIZE;
         }
-        return new PaginatedList<E>(pageSize, offset);
+        return new PaginatedList<>(pageSize, offset);
     }
     
     /**
@@ -54,7 +54,7 @@ public class PaginatedLists {
      * @param paginatedList Paginated list object containing parameters, and into which results are added by side effects
      * @param queryParam Query parameters
      */
-    public static <E> void executeCountQuery(PaginatedList<E> paginatedList, QueryParam queryParam) {
+    private static <E> void executeCountQuery(PaginatedList<E> paginatedList, QueryParam queryParam) {
         StringBuilder sb = new StringBuilder("select count(*) as result_count from (");
         sb.append(queryParam.getQueryString());
         sb.append(") as t1");
@@ -70,7 +70,6 @@ public class PaginatedLists {
     /**
      * Executes a query and returns the data of the currunt page.
      * 
-     * @param em EntityManager
      * @param paginatedList Paginated list object containing parameters, and into which results are added by side effects
      * @param queryParam Query parameters
      * @return List of results

docs-web/src/main/java/com/sismics/docs/rest/resource/AppResource.java

@@ -595,7 +595,7 @@ public class AppResource extends BaseResource {
         
         // Get all files
         FileDao fileDao = new FileDao();
-        List<File> fileList = fileDao.findAll();
+        List<File> fileList = fileDao.findAll(0, Integer.MAX_VALUE);
         Map<String, File> fileMap = new HashMap<>();
         for (File file : fileList) {
             fileMap.put(file.getId(), file);