Example usage for java.util LinkedList isEmpty

Introduction

In this page you can find the example usage for java.util LinkedList isEmpty.

Prototype

boolean isEmpty();

Source Link

Document

Returns true if this list contains no elements.

Usage

From source file:io.druid.firehose.s3.StaticS3FirehoseFactory.java

@Override
public Firehose connect(StringInputRowParser firehoseParser) throws IOException {
    Preconditions.checkNotNull(s3Client, "null s3Client");

    final LinkedList<URI> objectQueue = Lists.newLinkedList(uris);

    return new FileIteratingFirehose(new Iterator<LineIterator>() {
        @Override//ww  w  . j a  v  a  2  s. c om
        public boolean hasNext() {
            return !objectQueue.isEmpty();
        }

        @Override
        public LineIterator next() {
            final URI nextURI = objectQueue.poll();

            final String s3Bucket = nextURI.getAuthority();
            final S3Object s3Object = new S3Object(
                    nextURI.getPath().startsWith("/") ? nextURI.getPath().substring(1) : nextURI.getPath());

            log.info("Reading from bucket[%s] object[%s] (%s)", s3Bucket, s3Object.getKey(), nextURI);

            try {
                final InputStream innerInputStream = s3Client
                        .getObject(new S3Bucket(s3Bucket), s3Object.getKey()).getDataInputStream();

                final InputStream outerInputStream = s3Object.getKey().endsWith(".gz")
                        ? CompressionUtils.gzipInputStream(innerInputStream)
                        : innerInputStream;

                return IOUtils.lineIterator(
                        new BufferedReader(new InputStreamReader(outerInputStream, Charsets.UTF_8)));
            } catch (Exception e) {
                log.error(e, "Exception reading from bucket[%s] object[%s]", s3Bucket, s3Object.getKey());

                throw Throwables.propagate(e);
            }
        }

        @Override
        public void remove() {
            throw new UnsupportedOperationException();
        }
    }, firehoseParser);
}

---

From source file:io.druid.firehose.oss.StaticOSSFirehoseFactory.java

@Override
public Firehose connect(StringInputRowParser firehoseParser) throws IOException {

    Preconditions.checkNotNull(ossClient, "null ossClient");

    final LinkedList<URI> objectQueue = Lists.newLinkedList(uris);

    return new FileIteratingFirehose(new Iterator<LineIterator>() {
        @Override//from   w w  w. j  a v  a  2s.  c om
        public boolean hasNext() {
            return !objectQueue.isEmpty();
        }

        @Override
        public LineIterator next() {
            final URI nextURI = objectQueue.poll();

            final String bucket = nextURI.getAuthority();
            final String key = nextURI.getPath().startsWith("/") ? nextURI.getPath().substring(1)
                    : nextURI.getPath();

            log.info("reading from bucket[%s] object[%s] (%s)", bucket, key, nextURI);

            try {
                final InputStream innerInputStream = ossClient.getObject(bucket, key).getObjectContent();

                final InputStream outerInputStream = key.endsWith(".gz")
                        ? CompressionUtils.gzipInputStream(innerInputStream)
                        : innerInputStream;

                return IOUtils.lineIterator(
                        new BufferedReader(new InputStreamReader(outerInputStream, Charsets.UTF_8)));
            } catch (Exception e) {
                log.error(e, "exception reading from bucket[%s] object[%s]", bucket, key);

                throw Throwables.propagate(e);
            }
        }

        @Override
        public void remove() {
            throw new UnsupportedOperationException();
        }
    }, firehoseParser);
}

---

From source file:fr.aliasource.webmail.pool.impl.KeepAliveTask.java

@Override
public void run() {
    LinkedList<T> dead = new LinkedList<T>();

    for (T t : availableObjects) {
        boolean isAlive = t.keepAlive();
        if (!isAlive) {
            logger.warn("Dead poolable item (" + t + "). will recycle.");
            dead.add(t);/*  w ww  . j av a 2s  .c o  m*/
        }
    }

    if (!dead.isEmpty()) {
        logger.warn("pool usage report: " + pool.getUsageReport());
    }

    for (T t : dead) {
        availableObjects.remove(t);
        recycle();
    }

    if (availableObjects.remainingCapacity() - pool.getUsageCount() > 0) {
        logger.error("Pool refilling failed this time: " + pool.getUsageReport());
    }
}

---

From source file:org.apache.hadoop.fs.shell.Count.java

@Override
protected void processOptions(LinkedList<String> args) {
    CommandFormat cf = new CommandFormat(1, Integer.MAX_VALUE, OPTION_QUOTA, OPTION_HUMAN, OPTION_HEADER);
    cf.addOptionWithValue(OPTION_TYPE);//w w  w.j ava2s .  co  m
    cf.parse(args);
    if (args.isEmpty()) { // default path is the current working directory
        args.add(".");
    }
    showQuotas = cf.getOpt(OPTION_QUOTA);
    humanReadable = cf.getOpt(OPTION_HUMAN);

    if (showQuotas) {
        String types = cf.getOptValue(OPTION_TYPE);

        if (null != types) {
            showQuotabyType = true;
            storageTypes = getAndCheckStorageTypes(types);
        } else {
            showQuotabyType = false;
        }
    }

    if (cf.getOpt(OPTION_HEADER)) {
        if (showQuotabyType) {
            out.println(ContentSummary.getStorageTypeHeader(storageTypes) + "PATHNAME");
        } else {
            out.println(ContentSummary.getHeader(showQuotas) + "PATHNAME");
        }
    }
}

---

From source file:org.apache.impala.infra.tableflattener.SchemaFlattener.java

private void createChildDataset(String name, Schema srcSchema, LinkedList<Field> parentFields,
        FlattenedSchema parentDataset) {
    // Ensure that the parent schema has an id field so the child can reference the
    // parent. A single id field is sufficient.
    if (parentFields.isEmpty() || !parentFields.getFirst().name().equals(parentDataset.getIdFieldName())) {
        parentFields.addFirst(SchemaUtil.createField(parentDataset.getIdFieldName(), Type.LONG));
    }/*from ww  w  .  j  a v a2 s  .c  o  m*/
    FlattenedSchema childDataset = new FlattenedSchema(name, parentDataset);
    LinkedList<Field> fields = Lists.newLinkedList();
    String parentIdFieldName = parentDataset.getName() + childDataset.getNameSeparator()
            + childDataset.getIdFieldName();
    Field parentIdField = SchemaUtil.createField(parentIdFieldName, Type.LONG);
    childDataset.setParentIdField(parentIdField);
    fields.add(parentIdField);
    Schema valueSchema;
    if (srcSchema.getType() == Type.ARRAY) {
        fields.add(SchemaUtil.createField(childDataset.getArrayIdxFieldName(), Type.LONG));
        valueSchema = srcSchema.getElementType();
    } else {
        Preconditions.checkState(srcSchema.getType() == Type.MAP);
        fields.add(SchemaUtil.createField(childDataset.getMapKeyFieldName(), Type.STRING));
        valueSchema = srcSchema.getValueType();
    }

    if (SchemaUtil.isSimpleType(valueSchema)) {
        fields.add(SchemaUtil.createField(childDataset.getCollectionValueFieldName(), valueSchema));
    } else {
        if (SchemaUtil.isNullable(valueSchema)) {
            fields.add(SchemaUtil.createField(
                    childDataset.getIsNullFieldName(childDataset.getCollectionValueFieldName()), Type.BOOLEAN));
            valueSchema = SchemaUtil.reduceUnionToNonNull(valueSchema);
        }
        if (SchemaUtil.requiresChildDataset(valueSchema)) {
            createChildDataset(childDataset.getChildOfCollectionName(), valueSchema, fields, childDataset);
        } else {
            addRecordFields(valueSchema, childDataset, fields,
                    childDataset.getCollectionValueFieldName() + childDataset.getNameSeparator());
        }
    }

    finishCreatingDataset(fields, childDataset);
}

---

From source file:com.act.reachables.CladeTraversal.java

/**
 * This function traverses the reachables tree from the given start point using BFS, adds all the chemical's derivatives
 * to a file based on if they pass the mechanistic validator, and the derivatives' reaction pathway from the target
 * is also logged. Finally, for all the reactions that did not pass the mechanistic validator, we render those reactions
 * for furthur analysis into a directory.
 *
 * @param startPointId            - The start point node id to traverse from
 * @param validatedInchisFileName - The file containing all the derivative inchis that pass the validator.
 * @param reactionPathwayFileName - The file containing the reaction pathway information from source to target.
 * @param renderedReactionDirName - The directory containing all the rendered chemical reactions that failed the
 *                                mechanistic validator.
 * @throws IOException//from   w  w w. j ava  2 s . c om
 */
private void traverseTreeFromStartPoint(Long startPointId, String validatedInchisFileName,
        String reactionPathwayFileName, String renderedReactionDirName) throws IOException {
    ReactionRenderer render = new ReactionRenderer();
    PrintWriter validatedInchisWriter = new PrintWriter(validatedInchisFileName, "UTF-8");
    PrintWriter reactionPathwayWriter = new PrintWriter(reactionPathwayFileName, "UTF-8");

    LinkedList<Long> queue = new LinkedList<>();
    queue.addAll(this.parentToChildren.get(startPointId));

    while (!queue.isEmpty()) {
        Long candidateId = queue.pop();
        validatedInchisWriter.println(db.readChemicalFromInKnowledgeGraph(candidateId).getInChI());
        reactionPathwayWriter.println(formatPathFromSrcToDerivativeOfSrc(startPointId, candidateId));

        Set<Long> children = this.parentToChildren.get(candidateId);
        if (children != null) {
            for (Long child : children) {
                for (Long rxnId : rxnIdsForEdge(candidateId, child)) {
                    // In the case of a negative rxn id, this signifies the reaction is happening in reverse to what is
                    // referenced in the DB. In order to get the correct db index, one has to transform this negative reaction
                    // into its actual id.
                    if (rxnId < 0) {
                        rxnId = Reaction.reverseNegativeId(rxnId);
                    }

                    // Validate the reaction and only add its children to the queue if the reaction makes sense to our internal
                    // ros and the child is not in the queue already.
                    Map<Integer, List<Ero>> validatorResults = this.validator.validateOneReaction(rxnId);
                    if (validatorResults != null && validatorResults.size() > 0 && !queue.contains(child)) {
                        queue.add(child);
                    } else {
                        try {
                            render.drawReaction(db.getReadDB(), rxnId, renderedReactionDirName, true);
                        } catch (Exception e) {
                            LOGGER.error(
                                    "Error caught when trying to draw and save reaction %d with error message: %s",
                                    rxnId, e.getMessage());
                        }
                    }
                }
            }
        }
    }

    reactionPathwayWriter.close();
    validatedInchisWriter.close();
}

---

From source file:org.apache.camel.component.pdf.text.DefaultLineBuilderStrategy.java

/**
 * Builds lines from words. Utilizes the same behaviour as office software:
 * <ul>//from w  ww  .j av a 2s .c  o m
 *     <li>If word doesn't fit in current line, and current lines contains other words, then
 *     it will be moved to new line.</td>
 *     <li>Word doesn't fit in the line and line does not contain other words, then word will be
 *     slitted, and split index will be on max amount of characters that fits in the line </li>
 * </ul>
 */
@Override
public Collection<String> buildLines(Collection<String> splittedText) throws IOException {
    LinkedList<String> wordsList = new LinkedList<String>(splittedText);
    Collection<String> lines = new ArrayList<String>();
    LineBuilder currentLine = new LineBuilder();
    float allowedLineWidth = getAllowedLineWidth();
    while (!wordsList.isEmpty()) {
        String word = wordsList.removeFirst();
        if (isWordFitInCurrentLine(currentLine, word, allowedLineWidth)) {
            currentLine.appendWord(word);
            if (wordsList.isEmpty()) {
                lines.add(currentLine.buildLine());
            }
        } else if (currentLine.getWordsCount() != 0) {
            lines.add(currentLine.buildLine());
            wordsList.addFirst(word);
        } else {
            int splitIndex = findSplitIndex(word, allowedLineWidth);
            currentLine.appendWord(word.substring(0, splitIndex));
            lines.add(currentLine.buildLine());
            wordsList.addFirst(word.substring(splitIndex));
        }
    }
    return lines;
}

---

From source file:com.icantrap.collections.dawg.DawgBuilder.java

private void compress() {
    LinkedList<Node> stack = new LinkedList<Node>();
    int index = 0;

    stack.addLast(root);//from ww  w  .ja v  a 2  s. com
    while (!stack.isEmpty()) {
        Node ptr = stack.removeFirst();

        ptr.index = index++;
        if (root != ptr)
            ptr.siblings = ptr.parent.nextChildren.size() - 1 + (null == ptr.parent.child ? 0 : 1);
        nodeList.add(ptr);

        for (Node nextChild : ptr.nextChildren)
            stack.add(nextChild);
        if (null != ptr.child)
            stack.add(ptr.child);
    }

    // assign child depths to all nodes
    for (Node node : nodeList)
        if (node.terminal) {
            node.childDepth = 0;

            Node ptr = node;
            int depth = 0;
            while (root != ptr) {
                ptr = ptr.parent;
                ++depth;
                if (depth > ptr.childDepth)
                    ptr.childDepth = depth;
                else
                    break;
            }
        }

    // bin nodes by child depth
    for (Node node : nodeList) {
        LinkedList<Node> nodes = childDepths.get(node.childDepth);
        if (null == nodes) {
            nodes = new LinkedList<Node>();
            nodes.add(node);
            childDepths.put(node.childDepth, nodes);
        } else
            nodes.add(node);
    }

    int maxDepth = -1;
    for (int depth : childDepths.keySet())
        if (depth > maxDepth)
            maxDepth = depth;

    for (int depth = 0; depth <= maxDepth; ++depth) {
        LinkedList<Node> nodes = childDepths.get(depth);
        if (null == nodes)
            continue;

        for (ListIterator<Node> pickNodeIter = nodes.listIterator(); pickNodeIter.hasNext();) {
            Node pickNode = pickNodeIter.next();

            if ((null == pickNode.replaceMeWith) && pickNode.isChild && (0 == pickNode.siblings))
                for (ListIterator<Node> searchNodeIter = nodes
                        .listIterator(pickNodeIter.nextIndex()); searchNodeIter.hasNext();) {
                    Node searchNode = searchNodeIter.next();
                    if ((null == searchNode.replaceMeWith) && searchNode.isChild && (0 == searchNode.siblings)
                            && pickNode.equals(searchNode)) {
                        searchNode.parent.child = pickNode;
                        searchNode.replaceMeWith = pickNode;
                    }
                }
        }
    }
}

---

From source file:com.mongodb.hadoop.splitter.ShardChunkMongoSplitter.java

@Override
public List<InputSplit> calculateSplits() throws SplitFailedException {
    this.init();/*from  w  ww.j  a v a 2s  . c  om*/
    boolean targetShards = MongoConfigUtil.canReadSplitsFromShards(conf);
    DB configDB = this.mongo.getDB("config");
    DBCollection chunksCollection = configDB.getCollection("chunks");

    MongoClientURI inputURI = MongoConfigUtil.getInputURI(conf);
    String inputNS = inputURI.getDatabase() + "." + inputURI.getCollection();

    DBCursor cur = chunksCollection.find(new BasicDBObject("ns", inputNS));

    int numChunks = 0;

    Map<String, String> shardsMap = null;
    if (targetShards) {
        try {
            shardsMap = this.getShardsMap();
        } catch (Exception e) {
            //Something went wrong when trying to
            //read the shards data from the config server,
            //so abort the splitting
            throw new SplitFailedException("Couldn't get shards information from config server", e);
        }
    }

    List<String> mongosHostNames = MongoConfigUtil.getInputMongosHosts(this.conf);
    if (targetShards && mongosHostNames.size() > 0) {
        throw new SplitFailedException(
                "Setting both mongo.input.split.read_from_shards and mongo.input.mongos_hosts"
                        + " does not make sense. ");
    }

    if (mongosHostNames.size() > 0) {
        LOG.info("Using multiple mongos instances (round robin) for reading input.");
    }

    Map<String, LinkedList<InputSplit>> shardToSplits = new HashMap<String, LinkedList<InputSplit>>();

    while (cur.hasNext()) {
        final BasicDBObject row = (BasicDBObject) cur.next();
        BasicDBObject chunkLowerBound = (BasicDBObject) row.get("min");
        BasicDBObject chunkUpperBound = (BasicDBObject) row.get("max");
        MongoInputSplit chunkSplit = createSplitFromBounds(chunkLowerBound, chunkUpperBound);
        chunkSplit.setInputURI(inputURI);
        String shard = (String) row.get("shard");
        if (targetShards) {
            //The job is configured to target shards, so replace the
            //mongos hostname with the host of the shard's servers
            String shardHosts = shardsMap.get(shard);
            if (shardHosts == null) {
                throw new SplitFailedException("Couldn't find shard ID: " + shard + " in config.shards.");
            }

            MongoClientURI newURI = rewriteURI(inputURI, shardHosts);
            chunkSplit.setInputURI(newURI);
        } else if (mongosHostNames.size() > 0) {
            //Multiple mongos hosts are specified, so
            //choose a host name in round-robin fashion
            //and rewrite the URI using that hostname.
            //This evenly distributes the load to avoid
            //pegging a single mongos instance.
            String roundRobinHost = mongosHostNames.get(numChunks % mongosHostNames.size());
            MongoClientURI newURI = rewriteURI(inputURI, roundRobinHost);
            chunkSplit.setInputURI(newURI);
        }
        LinkedList<InputSplit> shardList = shardToSplits.get(shard);
        if (shardList == null) {
            shardList = new LinkedList<InputSplit>();
            shardToSplits.put(shard, shardList);
        }
        shardList.add(chunkSplit);
        numChunks++;
    }

    final List<InputSplit> splits = new ArrayList<InputSplit>(numChunks);
    int splitIndex = 0;
    while (splitIndex < numChunks) {
        Set<String> shardSplitsToRemove = new HashSet<String>();
        for (Map.Entry<String, LinkedList<InputSplit>> shardSplits : shardToSplits.entrySet()) {
            LinkedList<InputSplit> shardSplitsList = shardSplits.getValue();
            InputSplit split = shardSplitsList.pop();
            splits.add(splitIndex, split);
            splitIndex++;
            if (shardSplitsList.isEmpty()) {
                shardSplitsToRemove.add(shardSplits.getKey());
            }
        }
        for (String shardName : shardSplitsToRemove) {
            shardToSplits.remove(shardName);
        }
    }

    return splits;
}

---

From source file:com.asakusafw.runtime.directio.DirectDataSourceRepository.java

/**
 * Returns all {@link DirectDataSource}s registered in this repository.
 * @return all {@link DirectDataSource}s
 * @throws IOException if failed to initialize data sources
 * @throws InterruptedException if interrupted
 *///from w  w  w  .  j a va  2 s. c om
public Collection<String> getContainerPaths() throws IOException, InterruptedException {
    Collection<String> results = new ArrayList<>();
    LinkedList<Node> work = new LinkedList<>();
    work.add(root);
    while (work.isEmpty() == false) {
        Node node = work.removeFirst();
        if (node.hasContent()) {
            results.add(node.path.getPathString());
        }
        work.addAll(node.children.values());
    }
    return results;
}

---

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