Examples with PreparedQuery com.google.appengine.api.datastore.PreparedQuery used on opensource projects

Example 6 with PreparedQuery

use of com.google.appengine.api.datastore.PreparedQuery in project qi4j-sdk by Qi4j.

the class GaeEntityStoreMixin method entityStates.

@Override
public Input<Reader, IOException> entityStates() {
    return new Input<Reader, IOException>() {

        @Override
        public <ReceiverThrowableType extends Throwable> void transferTo(Output<? super Reader, ReceiverThrowableType> output) throws IOException, ReceiverThrowableType {
            Query query = new Query();
            PreparedQuery preparedQuery = datastore.prepare(query);
            final QueryResultIterable<Entity> iterable = preparedQuery.asQueryResultIterable();
            output.receiveFrom(new Sender<Reader, IOException>() {

                @Override
                public <ReceiverThrowableType extends Throwable> void sendTo(Receiver<? super Reader, ReceiverThrowableType> receiver) throws ReceiverThrowableType, IOException {
                    for (Entity entity : iterable) {
                        Text serializedState = (Text) entity.getProperty("value");
                        receiver.receive(new StringReader(serializedState.getValue()));
                    }
                }
            });
        }
    };
}

Example 7 with PreparedQuery

use of com.google.appengine.api.datastore.PreparedQuery in project siena by mandubian.

the class GaePersistenceManager method fillAggregated.

protected <T> void fillAggregated(ClassInfo info, T ancestor, Key ancestorKey) {
    // now gets aggregated one2one (one2many are retrieved by ListQuery except with @Join)
    for (Field f : info.aggregatedFields) {
        Class<?> cClazz = f.getType();
        ClassInfo cInfo = ClassInfo.getClassInfo(cClazz);
        if (ClassInfo.isModel(cClazz)) {
            // creates a query for fieldname:child_tablename
            com.google.appengine.api.datastore.Query q = new com.google.appengine.api.datastore.Query(GaeMappingUtils.getKindWithAncestorField(cInfo, info, f));
            PreparedQuery pq = ds.prepare(q.setAncestor(ancestorKey));
            Entity cEntity = pq.asSingleEntity();
            Object cObj = Util.createObjectInstance(cClazz);
            GaeMappingUtils.fillModelAndKey(cObj, cEntity);
            Util.setField(ancestor, f, cObj);
        } else // todo manage joined one2many listquery
        if (ClassInfo.isMany(f)) {
            Many4PM<?> lq = (Many4PM<?>) Util.readField(ancestor, f);
            // sets the sync flag to false to tell that it should be fetched when the listquery is accessed!
            lq.setSync(false);
        }
    }
}

Example 8 with PreparedQuery

use of com.google.appengine.api.datastore.PreparedQuery in project siena by mandubian.

the class GaePersistenceManagerAsync method doFetchIterable.

private <T> SienaFuture<Iterable<T>> doFetchIterable(QueryAsync<T> query, int limit, int offset) {
    QueryOptionGaeContext gaeCtx = (QueryOptionGaeContext) query.option(QueryOptionGaeContext.ID);
    QueryOptionState state = (QueryOptionState) query.option(QueryOptionState.ID);
    QueryOptionFetchType fetchType = (QueryOptionFetchType) query.option(QueryOptionFetchType.ID);
    if (gaeCtx == null) {
        gaeCtx = new QueryOptionGaeContext();
        query.customize(gaeCtx);
    }
    FetchOptions fetchOptions = FetchOptions.Builder.withDefaults();
    QueryOptionPage pag = (QueryOptionPage) query.option(QueryOptionPage.ID);
    if (!pag.isPaginating()) {
        // no pagination but pageOption active
        if (pag.isActive()) {
            // if local limit is set, it overrides the pageOption.pageSize
            if (limit != Integer.MAX_VALUE) {
                gaeCtx.realPageSize = limit;
                fetchOptions.limit(gaeCtx.realPageSize);
                // pageOption is passivated to be sure it is not reused
                pag.passivate();
            } else // using pageOption.pageSize
            {
                gaeCtx.realPageSize = pag.pageSize;
                fetchOptions.limit(gaeCtx.realPageSize);
                // passivates the pageOption in stateless mode not to keep anything between 2 requests
                if (state.isStateless()) {
                    pag.passivate();
                }
            }
        } else {
            if (limit != Integer.MAX_VALUE) {
                gaeCtx.realPageSize = limit;
                fetchOptions.limit(gaeCtx.realPageSize);
            }
        }
    } else {
        // paginating so use the pagesize and don't passivate pageOption
        // local limit is not taken into account
        gaeCtx.realPageSize = pag.pageSize;
        fetchOptions.limit(gaeCtx.realPageSize);
    }
    QueryOptionOffset off = (QueryOptionOffset) query.option(QueryOptionOffset.ID);
    // if local offset has been set, uses it
    if (offset != 0) {
        off.activate();
        off.offset = offset;
    }
    // if previousPage has detected there is no more data, simply returns an empty list
    if (gaeCtx.noMoreDataBefore) {
        return new SienaFutureMock<Iterable<T>>(new ArrayList<T>());
    }
    if (state.isStateless()) {
        if (pag.isPaginating()) {
            if (off.isActive()) {
                gaeCtx.realOffset += off.offset;
                fetchOptions.offset(gaeCtx.realOffset);
                off.passivate();
            } else {
                fetchOptions.offset(gaeCtx.realOffset);
            }
        } else {
            // if stateless and not paginating, resets the realoffset to 0
            gaeCtx.realOffset = off.offset;
            if (off.isActive()) {
                fetchOptions.offset(gaeCtx.realOffset);
                off.passivate();
            }
        }
        switch(fetchType.fetchType) {
            case ITER:
            default:
                {
                    // uses iterable as it is the only async request for prepared query for the time being
                    Iterable<Entity> entities = prepare(query).asIterable(fetchOptions);
                    return new GaeSienaFutureIterableMapper<T>(this, entities, query);
                }
        }
    } else {
        if (off.isActive()) {
            // by default, we add the offset but it can be added with the realoffset 
            // in case of cursor desactivated
            fetchOptions.offset(off.offset);
            gaeCtx.realOffset += off.offset;
            off.passivate();
        }
        // manages cursor limitations for IN and != operators		
        if (!gaeCtx.isActive()) {
            // cursor not yet created
            switch(fetchType.fetchType) {
                case ITER:
                default:
                    {
                        PreparedQuery pq = prepare(query);
                        if (pag.isPaginating()) {
                            // in case of pagination, we need to allow asynchronous calls such as:
                            // QueryAsync<MyClass> query = pm.createQuery(MyClass).paginate(5).stateful().order("name");
                            // SienaFuture<Iterable<MyClass>> future1 = query.iter();
                            // SienaFuture<Iterable<MyClass>> future2 = query.nextPage().iter();
                            // Iterable<MyClass> it = future1.get().iterator();
                            // while(it.hasNext()) { // do it }
                            // it = future2.get().iterator();
                            // while(it.hasNext()) { // do it }
                            // so we can't use the asQueryResultIterable as the cursor is not moved to the end of the current page
                            // but moved at each call of iterable.iterator().next()
                            // thus we use the List in this case to be able to move directly to the next page with cursors
                            QueryResultList<Entity> entities = pq.asQueryResultList(fetchOptions);
                            // activates the GaeCtx now that it is initialised
                            gaeCtx.activate();
                            // sets the current cursor (in stateful mode, cursor is always kept for further use)
                            //if(gaeCtx.useCursor){
                            Cursor cursor = entities.getCursor();
                            if (cursor != null) {
                                gaeCtx.addCursor(cursor.toWebSafeString());
                            }
                            return new GaeSienaFutureIterableMapper<T>(this, entities, query);
                        } else {
                            // if not paginating, we simply use the queryresultiterable and moves the current cursor
                            // while iterating
                            QueryResultIterable<Entity> entities = pq.asQueryResultIterable(fetchOptions);
                            // activates the GaeCtx now that it is initialised
                            gaeCtx.activate();
                            return new GaeSienaFutureIterableMapperWithCursor<T>(this, entities, query);
                        }
                    }
            }
        } else {
            switch(fetchType.fetchType) {
                case ITER:
                default:
                    {
                        PreparedQuery pq = prepare(query);
                        if (pag.isPaginating()) {
                            // in case of pagination, we need to allow asynchronous calls such as:
                            // QueryAsync<MyClass> query = pm.createQuery(MyClass).paginate(5).stateful().order("name");
                            // SienaFuture<Iterable<MyClass>> future1 = query.iter();
                            // SienaFuture<Iterable<MyClass>> future2 = query.nextPage().iter();
                            // Iterable<MyClass> it = future1.get().iterator();
                            // while(it.hasNext()) { // do it }
                            // it = future2.get().iterator();
                            // while(it.hasNext()) { // do it }
                            // so we can't use the asQueryResultIterable as the cursor is not moved to the end of the current page
                            // but moved at each call of iterable.iterator().next()
                            // thus we use the List in this case to be able to move directly to the next page with cursors
                            QueryResultList<Entity> entities;
                            if (!gaeCtx.useCursor) {
                                // then uses offset (in case of IN or != operators)
                                //if(offset.isActive()){
                                //	fetchOptions.offset(offset.offset);
                                //}
                                fetchOptions.offset(gaeCtx.realOffset);
                                entities = pq.asQueryResultList(fetchOptions);
                            } else {
                                String cursor = gaeCtx.currentCursor();
                                if (cursor != null) {
                                    entities = pq.asQueryResultList(fetchOptions.startCursor(Cursor.fromWebSafeString(cursor)));
                                } else {
                                    entities = pq.asQueryResultList(fetchOptions);
                                }
                                // sets the current cursor (in stateful mode, cursor is always kept for further use)
                                //if(gaeCtx.useCursor){
                                gaeCtx.addCursor(entities.getCursor().toWebSafeString());
                            //}
                            }
                            return new GaeSienaFutureIterableMapper<T>(this, entities, query);
                        } else {
                            // if not paginating, we simply use the queryresultiterable and moves the current cursor
                            // while iterating
                            QueryResultIterable<Entity> entities;
                            if (!gaeCtx.useCursor) {
                                // then uses offset (in case of IN or != operators)
                                //if(offset.isActive()){
                                //	fetchOptions.offset(offset.offset);
                                //}
                                fetchOptions.offset(gaeCtx.realOffset);
                                entities = pq.asQueryResultIterable(fetchOptions);
                            } else {
                                String cursor = gaeCtx.currentCursor();
                                if (cursor != null) {
                                    entities = pq.asQueryResultIterable(fetchOptions.startCursor(Cursor.fromWebSafeString(gaeCtx.currentCursor())));
                                } else {
                                    entities = pq.asQueryResultIterable(fetchOptions);
                                }
                            }
                            return new GaeSienaFutureIterableMapperWithCursor<T>(this, entities, query);
                        }
                    }
            }
        }
    }
}