Examples of DBCursor

com.massivecraft.mcore.xlib.mongodb.DBCursor
An iterator over database results. Doing a find() query on a collection returns a DBCursor thus
```
 DBCursor cursor = collection.find( query ); if( cursor.hasNext() ) DBObject obj = cursor.next(); 
```
Warning: Calling toArray or length on a DBCursor will irrevocably turn it into an array. This means that, if the cursor was iterating over ten million results (which it was lazily fetching from the database), suddenly there will be a ten-million element array in memory. Before converting to an array, make sure that there are a reasonable number of results using skip() and limit().
For example, to get an array of the 1000-1100th elements of a cursor, use
```
 List obj = collection.find( query ).skip( 1000 ).limit( 100 ).toArray(); 
```
@dochub cursors
com.mongodb.DBCursor
An iterator over database results. Doing a find() query on a collection returns a DBCursor thus
```
 DBCursor cursor = collection.find( query ); if( cursor.hasNext() ) DBObject obj = cursor.next(); 
```
Warning: Calling toArray or length on a DBCursor will irrevocably turn it into an array. This means that, if the cursor was iterating over ten million results (which it was lazily fetching from the database), suddenly there will be a ten-million element array in memory. Before converting to an array, make sure that there are a reasonable number of results using skip() and limit().
For example, to get an array of the 1000-1100th elements of a cursor, use
```
 List obj = collection.find( query ).skip( 1000 ).limit( 100 ).toArray(); 
```
@dochub cursors
com.sun.sgs.service.store.db.DbCursor
The interface to a cursor for iterating over the contents of a database. A newly created cursor has no current key or value. Cursors are associated with a single transaction, and must be created and closed within that single transaction. Cursors must not be used after the {@link #close close} methodis called. Cursor implementations are not required to be synchronized.

Examples of com.mongodb.DBCursor

                } else if (association.isOneToOneAssociation()) {
                    query.put(association.getIdentifier().getMemberName(), field.getOid());
                }
            }
        }
        final DBCursor cursor = instances.find(query);
        LOG.info("searching for instances of: " + objectSpecId);
        return new Iterator<StateReader>() {
            @Override
            public boolean hasNext() {
                return cursor.hasNext();
            }


            @Override
            public StateReader next() {
                return new MongoStateReader(cursor.next());
            }


            @Override
            public void remove() {
                throw new NoSqlStoreException("Can't remove elements");

View Full Code Here

Examples of com.mongodb.DBCursor

                if (input.containsKey("$select")) {
                    select = buildDBObject((MongoRecord)input.get("$select"));
                    input.remove("$select");
                }
                DBObject object = buildDBObject(input);
                DBCursor cursor = collection.find(object, select);
                if (sort != null) {
                    cursor.sort(sort);
                }
                try {
                    if (mongoSpec.getSkip() > 0) {
                        cursor.skip(mongoSpec.getSkip());
                    }
                    if (mongoSpec.getLimit() != 0) {
                        cursor.limit(mongoSpec.getLimit());
                    }
                    if (mongoSpec.getBatchSize() != 0) {
                        cursor.batchSize(mongoSpec.getBatchSize());
                    }
                    if (!cursor.hasNext()) {
                        return null;
                    }
                    MongoListRecord results = new MongoListRecord();
                    while (cursor.hasNext()) {
                        DBObject result = cursor.next();
                        results.add(buildRecordFromDBObject(result));
                    }
                    return results;
                } finally {
                    cursor.close();
                }


            } else {
                throw new ResourceException("Invalid operation: " + operation);                
            }

View Full Code Here

Examples of com.mongodb.DBCursor

    }
  }


  private ClosableIterator<Tuple> doFind(MongoDBQueryDescriptor query, QueryParameters queryParameters, DBCollection collection,
      EntityKeyMetadata entityKeyMetadata) {
    DBCursor cursor = collection.find( query.getCriteria(), query.getProjection() );


    if ( query.getOrderBy() != null ) {
      cursor.sort( query.getOrderBy() );
    }


    // apply firstRow/maxRows if present
    if ( queryParameters.getRowSelection().getFirstRow() != null ) {
      cursor.skip( queryParameters.getRowSelection().getFirstRow() );
    }


    if ( queryParameters.getRowSelection().getMaxRows() != null ) {
      cursor.limit( queryParameters.getRowSelection().getMaxRows() );
    }


    return new MongoDBResultsCursor( cursor, entityKeyMetadata );
  }

View Full Code Here

Examples of com.mongodb.DBCursor

        queryBuilder.and("_id").greaterThan(parent + "/");
        queryBuilder.and("_id").lessThanEquals(parent + "0");
        DBObject query = queryBuilder.get();
        BasicDBObject keys = new BasicDBObject();
        keys.put("_id", 1);
        DBCursor cursor = nodes.find(query, keys);
        int count = 0;
        log("Query plan: " + cursor.explain());
        long time = System.currentTimeMillis();
        while (cursor.hasNext()) {
            DBObject obj = cursor.next();
            // dummy read operation (to ensure we did get the data)
            obj.get("_id");
            count++;
            // log(" read " + obj);
        }

View Full Code Here

Examples of com.mongodb.DBCursor

            queryBuilder.greaterThanEquals(startValue);
        }
        DBObject query = queryBuilder.get();
        long start = start();
        try {
            DBCursor cursor = dbCollection.find(query).sort(BY_ID_ASC);
            List<T> list = new ArrayList<T>();
            for (int i = 0; i < limit && cursor.hasNext(); i++) {
                DBObject o = cursor.next();
                T doc = convertFromDBObject(collection, o);
                if (collection == Collection.NODES && doc != null) {
                    doc.seal();
                    String id = doc.getId();
                    Lock lock = getAndLock(id);

View Full Code Here

Examples of com.mongodb.DBCursor

            // Fetch only the lastRev map and id
            final BasicDBObject keys = new BasicDBObject(Document.ID, 1);
            keys.put(Document.MOD_COUNT, 1);


            // Fetch lastRev for each such node
            DBCursor cursor = nodes.find(query.get(), keys);
            result.queryCount++;


            for (DBObject obj : cursor) {
                result.cacheEntriesProcessedCount++;
                String id = (String) obj.get(Document.ID);

View Full Code Here

Examples of com.mongodb.DBCursor


                    QueryBuilder query = QueryBuilder.start(Document.ID)
                            .in(sameLevelNodes.keySet());


                    // Fetch lastRev and modCount for each such nodes
                    DBCursor cursor = nodes.find(query.get(), keys);
                    LOG.debug(
                            "Checking for changed nodes at level {} with {} paths",
                            tn.level(), sameLevelNodes.size());
                    result.queryCount++;
                    for (DBObject obj : cursor) {

View Full Code Here

Examples of com.mongodb.DBCursor

        QueryBuilder builder = new QueryBuilder();
        if (maxLastModifiedTime != 0 && maxLastModifiedTime != -1) {
            builder.and(MongoBlob.KEY_LAST_MOD).lessThanEquals(maxLastModifiedTime);
        }


        final DBCursor cur =
                collection.find(builder.get(), fields).hint(fields)
                        .addOption(Bytes.QUERYOPTION_SLAVEOK);


        return new AbstractIterator<String>() {
            protected String computeNext() {
                if (cur.hasNext()) {
                    MongoBlob blob = (MongoBlob) cur.next();
                    if (blob != null) {
                        return blob.getId();
                    }
                }
                return endOfData();

View Full Code Here

Examples of com.mongodb.DBCursor

     *            the name of the collection
     * @return a table definition for mongo db.
     */
    public static SimpleTableDef detectTable(DB db, String collectionName) {
        final DBCollection collection = db.getCollection(collectionName);
        final DBCursor cursor = collection.find().limit(1000);


        final SortedMap<String, Set<Class<?>>> columnsAndTypes = new TreeMap<String, Set<Class<?>>>();
        while (cursor.hasNext()) {
            DBObject object = cursor.next();
            Set<String> keysInObject = object.keySet();
            for (String key : keysInObject) {
                Set<Class<?>> types = columnsAndTypes.get(key);
                if (types == null) {
                    types = new HashSet<Class<?>>();
                    columnsAndTypes.put(key, types);
                }
                Object value = object.get(key);
                if (value != null) {
                    types.add(value.getClass());
                }
            }
        }
        cursor.close();


        final String[] columnNames = new String[columnsAndTypes.size()];
        final ColumnType[] columnTypes = new ColumnType[columnsAndTypes.size()];


        int i = 0;

View Full Code Here

Examples of com.mongodb.DBCursor

        final DBCollection collection = _mongoDb.getCollection(table.getName());


        final DBObject query = createMongoDbQuery(table, whereItems);


        logger.info("Executing MongoDB 'find' query: {}", query);
        DBCursor cursor = collection.find(query);


        if (maxRows > 0) {
            cursor = cursor.limit(maxRows);
        }
        if (firstRow > 1) {
            final int skip = firstRow - 1;
            cursor = cursor.skip(skip);
        }


        return new MongoDbDataSet(cursor, columns, queryPostProcessed);
    }

View Full Code Here

0 1 2 3 4 5

TOP

All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.