Example usage for java.util Queue poll

List of usage examples for java.util Queue poll

  1. HOME
  2. Java
  3. java
  4. java.util.*
  5. Queue
  6. poll

Introduction

In this page you can find the example usage for java.util Queue poll.

Prototype

E poll();

Source Link

Document

Retrieves and removes the head of this queue, or returns null if this queue is empty.

Usage

From source file:org.apache.hadoop.hbase.replication.regionserver.DumpReplicationQueues.java

static DumpOptions parseOpts(Queue<String> args) {
    DumpOptions opts = new DumpOptions();

    String cmd = null;// ww  w  . ja  va2s. c om
    while ((cmd = args.poll()) != null) {
        if (cmd.equals("-h") || cmd.equals("--h") || cmd.equals("--help")) {
            // place item back onto queue so that caller knows parsing was incomplete
            args.add(cmd);
            break;
        }
        final String hdfs = "--hdfs";
        if (cmd.equals(hdfs)) {
            opts.setHdfs(true);
            continue;
        }
        final String distributed = "--distributed";
        if (cmd.equals(distributed)) {
            opts.setDistributed(true);
            continue;
        } else {
            printUsageAndExit("ERROR: Unrecognized option/command: " + cmd, -1);
        }
        // check that --distributed is present when --hdfs is in the arguments
        if (!opts.isDistributed() && opts.isHdfs()) {
            printUsageAndExit("ERROR: --hdfs option can only be used with --distributed: " + cmd, -1);
        }
    }
    return opts;
}

From source file:com.wrmsr.wava.basic.BasicLoopInfo.java

public static Set<Name> getLoopContents(Name loop, Multimap<Name, Name> inputs,
        Multimap<Name, Name> backEdges) {
    Set<Name> seen = new HashSet<>();
    seen.add(loop);/*from   ww  w  . j  a v a  2 s.c  o m*/
    Queue<Name> queue = new LinkedList<>();
    inputs.get(loop).stream().filter(n -> !n.equals(loop) && backEdges.containsEntry(loop, n))
            .forEach(queue::add);
    queue.forEach(seen::add);
    while (!queue.isEmpty()) {
        Name cur = queue.poll();
        inputs.get(cur).stream().filter(input -> !seen.contains(input)).forEach(input -> {
            seen.add(input);
            queue.add(input);
        });
    }
    return seen;
}

From source file:org.xwiki.xdomviz.Main.java

/**
 * <p>//from w ww .j  av a  2 s.co m
 * This method performs a normalization of the tree by removing all the multi-edges (due to a node having multiple
 * parents). This happens often with SpaceBlocks, which are reused all over the XDOM. The algorithm performs a
 * breadth first visit. For each visited node, it checks how many times a child occurs in its children list. If a
 * child occurs more than once, then we create new nodes, one for each occurrence.
 * </p>
 * <p>
 * The node tree corresponding to the XDOM of "this is a test" is:
 * </p>
 * <ul>
 * <li>XDOM -> P</li>
 * <li>P -> "This"</li>
 * <li>P -> S (3 edges, each one representing a space)</li>
 * <li>P -> "is"</li>
 * <li>P -> "a"</li>
 * <li>P -> "test"</li>
 * </ul>
 * <p>
 * The normalized tree will be:
 * </p>
 * <ul>
 * <li>XDOM -> P</li>
 * <li>P -> "This"</li>
 * <li>P -> S</li>
 * <li>P -> "is"</li>
 * <li>P -> S</li>
 * <li>P -> "a"</li>
 * <li>P -> S</li>
 * <li>P -> "test"</li>
 * </ul>
 * <p>
 * In a normalized tree, each node has one and only one parent.
 * </p>
 * 
 * @param root The root node of the tree.
 * @return The root node of the normalized tree.
 */
private static Node normalize(Node root) {
    // Breadth first visit of the XDOM to assign simple ids to nodes.
    Queue<Node> nodesQueue = new ArrayDeque<Node>();
    nodesQueue.add(root);
    while (!nodesQueue.isEmpty()) {
        Node node = nodesQueue.poll();

        // This map contains, for the current node, where are the occurrences in the children list of each child.
        Map<Node, List<Integer>> nodeToIndexesMap = new HashMap<Node, List<Integer>>();

        int i = 0;
        // For each child calculate store the its position in the indexes list.
        for (Node child : node.getChildren()) {
            List<Integer> indexes = nodeToIndexesMap.get(child);
            if (indexes == null) {
                indexes = new ArrayList<Integer>();
                nodeToIndexesMap.put(child, indexes);
            }
            indexes.add(i);
            i++;
        }

        for (Node child : nodeToIndexesMap.keySet()) {
            List<Integer> indexes = nodeToIndexesMap.get(child);
            // If the indexes size is > 1 then a child occurs multiple times in a
            if (indexes.size() > 1) {
                for (Integer index : indexes) {
                    Node newNode = new Node(child.getBlock());
                    newNode.getParents().add(node);
                    newNode.getChildren().addAll(child.getChildren());
                    node.getChildren().set(index, newNode);
                }
            }
        }

        for (Node child : node.getChildren()) {
            nodesQueue.add(child);
        }
    }

    return root;
}

From source file:org.xwiki.xdomviz.Main.java

/**
 * <p>/*from w w w. ja v  a  2 s.c o  m*/
 * This method creates an isomorphic tree using node structures instead of blocks. This is necessary because a
 * single XDOM's block can be a child of multiple parents but the getParent() method is able to return only a single
 * parent. Using this alternative representation, full parent information is correctly stored in each node.
 * </p>
 * <p>
 * The node tree representation allows also the manipulation of the tree structure because all the attributes of a
 * node are mutable.
 * </p>
 * 
 * @param xdom
 * @return The root node of the new tree.
 */
private static Node createNodeTree(XDOM xdom) {
    // The list of the nodes created from the visited XDOM's blocks.
    List<Node> nodes = new ArrayList<Node>();

    // Breadth first visit of the XDOM.
    Queue<Block> blocksQueue = new ArrayDeque<Block>();
    blocksQueue.add(xdom.getRoot());
    while (!blocksQueue.isEmpty()) {
        Block block = blocksQueue.poll();

        // If there isn't a node corresponding to this block, create it!
        Node parentNode = findNode(nodes, block);
        if (parentNode == null) {
            parentNode = new Node(block);
            nodes.add(parentNode);
        }

        for (Block child : block.getChildren()) {
            blocksQueue.add(child);

            // If there isn't a node corresponding to this child-block, create it!
            Node childNode = findNode(nodes, child);
            if (childNode == null) {
                childNode = new Node(child);
                nodes.add(childNode);
            }

            // Link parent and child child.
            parentNode.getChildren().add(childNode);
            childNode.getParents().add(parentNode);
        }
    }

    return findNode(nodes, xdom.getRoot());
}

From source file:org.janusgraph.util.system.ConfigurationFileFilter.java

public static int filter(String inputContextDirPath, String outputContextDirPath) throws IOException {

    // Read args[0] as a dirname and iterate recursively over its file contents
    File inputContextDir = new File(inputContextDirPath);
    File outputContextDir = new File(outputContextDirPath);

    log.info("Input context dir:  {}", inputContextDir);
    log.info("Output context dir: {}", outputContextDir);
    Preconditions.checkArgument(inputContextDir.isDirectory(), "Input context dir %s is not a directory",
            inputContextDir);/*from  w  ww  . j  ava 2  s. c  o  m*/
    Preconditions.checkArgument(inputContextDir.canRead(), "Input context dir %s is not readable",
            inputContextDir);

    if (!outputContextDir.exists()) {
        outputContextDir.mkdirs(); // may fail if path exists as a file
    }

    Queue<InputRecord> dirQueue = new LinkedList<InputRecord>();
    dirQueue.add(new InputRecord(inputContextDir, File.separator));
    int parseErrors = 0;
    int visitedDirs = 0;
    int processedFiles = 0;
    InputRecord rec;
    while (null != (rec = dirQueue.poll())) {
        File curDir = rec.getDirectory();
        String contextPath = rec.getContextPath();

        Preconditions.checkState(curDir.exists());
        Preconditions.checkState(curDir.isDirectory());
        Preconditions.checkState(curDir.canRead());

        visitedDirs++;

        for (File f : curDir.listFiles()) {
            if (f.isDirectory()) {
                if (!f.canRead()) {
                    log.warn("Skipping unreadable directory {} in input basedir", f);
                    continue;
                }

                dirQueue.add(new InputRecord(f, contextPath + f.getName() + File.separator));
            } else {
                if (!f.canRead()) {
                    log.warn("Skipping unreadable file {} in input basedir", f);
                    continue;
                }

                File outputDir = new File(outputContextDir.getPath() + contextPath);

                if (!outputDir.exists()) {
                    outputDir.mkdirs();
                }

                parseErrors += processFile(f, new File(outputContextDir.getPath() + contextPath + f.getName()));

                processedFiles++;
            }
        }
    }

    String summaryTemplate = "Summary: visited {} dir(s) and processed {} file(s) with {} parse error(s).";

    if (0 == parseErrors) {
        log.info(summaryTemplate, visitedDirs, processedFiles, parseErrors);
    } else {
        log.error(summaryTemplate, visitedDirs, processedFiles, parseErrors);
    }

    return parseErrors;
}

From source file:eu.stratosphere.nephele.jobmanager.scheduler.RecoveryLogic.java

private static void findVerticesToRestart(final ExecutionVertex failedVertex,
        final Set<ExecutionVertex> verticesToBeCanceled) {

    final Queue<ExecutionVertex> verticesToTest = new ArrayDeque<ExecutionVertex>();
    final Set<ExecutionVertex> visited = new HashSet<ExecutionVertex>();
    verticesToTest.add(failedVertex);/*ww  w  . j a v a2s . co m*/

    while (!verticesToTest.isEmpty()) {

        final ExecutionVertex vertex = verticesToTest.poll();

        // Predecessors must be either checkpoints or need to be restarted, too
        for (int j = 0; j < vertex.getNumberOfPredecessors(); j++) {
            final ExecutionVertex predecessor = vertex.getPredecessor(j);

            if (hasInstanceAssigned(predecessor)) {
                verticesToBeCanceled.add(predecessor);
            }

            if (!visited.contains(predecessor)) {
                verticesToTest.add(predecessor);
            }
        }
        visited.add(vertex);
    }
}

From source file:com.demandware.vulnapp.util.Helpers.java

/**
 * Given a root dir and a file name, search all subdirectories for the file. 
 * /*w w w  .  j  ava  2  s .  c  o  m*/
 * @return null if root or name is null, or if the file is not found. the found file otherwise 
 */
public static File findFile(File root, String name) {
    if (root == null || name == null) {
        return null;
    }
    File foundFile = null;
    Queue<File> filesAndDirs = new LinkedList<File>();
    filesAndDirs.add(root);
    while (!filesAndDirs.isEmpty() && foundFile == null) {
        File file = filesAndDirs.poll();
        if (file.isDirectory()) {
            File[] files = file.listFiles();
            if (files != null) {
                for (File f : files) {
                    filesAndDirs.add(f);
                }
            }
        } else {
            if (file.getName().equals(name)) {
                foundFile = file;
            }
        }
    }
    return foundFile;
}

From source file:org.apache.tajo.rpc.RpcChannelFactory.java

/**
 * This function return eventloopgroup by key. Fetcher client will have one or more eventloopgroup for its throughput.
 *
 * @param clientId//from w  w  w . jav a2 s  .  c  o m
 * @param workerNum
 * @return
 */
public static EventLoopGroup getSharedClientEventloopGroup(ClientChannelId clientId, int workerNum) {
    Queue<EventLoopGroup> eventLoopGroupQueue;
    EventLoopGroup returnEventLoopGroup;

    synchronized (lockObjectForLoopGroup) {
        eventLoopGroupQueue = eventLoopGroupPool.get(clientId);
        if (eventLoopGroupQueue == null) {
            eventLoopGroupQueue = createClientEventloopGroups(clientId, workerNum);
        }

        returnEventLoopGroup = eventLoopGroupQueue.poll();
        if (isEventLoopGroupShuttingDown(returnEventLoopGroup)) {
            returnEventLoopGroup = createClientEventloopGroup(clientId.name(), workerNum);
        }
        eventLoopGroupQueue.add(returnEventLoopGroup);
    }

    return returnEventLoopGroup;
}

From source file:com.enderville.enderinstaller.util.InstallScript.java

/**
 * Repackages all the files in the tmp directory to the new minecraft.jar
 *
 * @param tmp The temp directory where mods were installed.
 * @param mcjar The location to save the new minecraft.jar.
 * @throws IOException//from w  w  w  . ja  v  a 2 s . c  om
 */
public static void repackMCJar(File tmp, File mcjar) throws IOException {
    byte[] dat = new byte[4 * 1024];

    JarOutputStream jarout = new JarOutputStream(FileUtils.openOutputStream(mcjar));

    Queue<File> queue = new LinkedList<File>();
    for (File f : tmp.listFiles()) {
        queue.add(f);
    }

    while (!queue.isEmpty()) {
        File f = queue.poll();
        if (f.isDirectory()) {
            for (File child : f.listFiles()) {
                queue.add(child);
            }
        } else {
            //TODO need a better way to do this
            String name = f.getPath().substring(tmp.getPath().length() + 1);
            //TODO is this formatting really required for jars?
            name = name.replace("\\", "/");
            if (f.isDirectory() && !name.endsWith("/")) {
                name = name + "/";
            }
            JarEntry entry = new JarEntry(name);
            jarout.putNextEntry(entry);

            FileInputStream in = new FileInputStream(f);
            int len = -1;
            while ((len = in.read(dat)) > 0) {
                jarout.write(dat, 0, len);
            }
            in.close();
        }
        jarout.closeEntry();
    }
    jarout.close();

}

From source file:org.xwiki.xdomviz.Main.java

/**
 * <p>// ww w . j a va  2 s.c  o  m
 * This method produces the GraphViz source code corresponding to the node tree.
 * </p>
 * 
 * @param root The node tree root.
 * @return A string containing the GraphViz source code to display the node tree.
 */
private static String generateGraphViz(Node root) {
    // The rendering buffer.
    StringBuffer sb = new StringBuffer();

    // This map contains the GraphViz Ids (integers) associated to the nodes in the tree.
    Map<Node, Integer> nodeToIdMap = new HashMap<Node, Integer>();

    sb.append("digraph XDOM {\n");

    // Breadth first visit of the XDOM to assign simple ids to nodes.
    Queue<Node> nodesQueue = new ArrayDeque<Node>();
    nodesQueue.add(root);
    // Counter used to keep track of the assigned ids. It's incremented at each time a new node is found for the
    // first time.
    int i = 0;
    while (!nodesQueue.isEmpty()) {
        Node node = nodesQueue.poll();

        if (nodeToIdMap.get(node) == null) {
            nodeToIdMap.put(node, i);
            i++;
        }

        for (Node child : node.getChildren()) {
            if (nodeToIdMap.get(child) == null) {
                nodeToIdMap.put(child, i);
                i++;
            }

            nodesQueue.add(child);

            // Render the edge.
            sb.append(String.format("%d -> %d;\n", nodeToIdMap.get(node), nodeToIdMap.get(child)));
        }
    }

    // Render the label assignment.
    for (Node node : nodeToIdMap.keySet()) {
        sb.append(String.format("%d [label = \"%s\"];\n", nodeToIdMap.get(node), node));
    }

    sb.append("}\n");

    return sb.toString();
}