Examples with Queue com.google.cloud.tasks.v2.Queue used on opensource projects

Example 21 with Queue

use of com.google.cloud.tasks.v2.Queue in project algorithms-sedgewick-wayne by reneargento.

the class Exercise26_CriticalEdges method findCriticalEdges.

/**
 * An edge e is critical if and only if it is a bridge in the subgraph containing all edges with weights
 * less than or equal to the weight of edge e.
 *
 * Proof:
 * 1st part: If an edge e is critical then it is a bridge in the subgraph containing all edges with weights
 * less than or equal to the weight of edge e.
 * Consider by contradiction that edge e is not a bridge in such subgraph. If it is not a bridge, then there is another
 * edge f that connects the same components as e in the subgraph and it has weight less than or equal to e.
 * In this case, edge e could be replaced by edge f in an MST and the MST weight would not increase.
 * However, since e is critical and cannot be replaced by an edge with weight less than or equal to it,
 * it must be a bridge in the subgraph.
 *
 * 2nd part: If an edge e is a bridge in the subgraph containing all edges with weights less than or equal to its
 * weight then e is critical.
 * Consider by contradiction that e is not critical. If e is not critical, then there must be another edge that
 * could replace it in an MST and would not cause the MST weight to increase.
 * However, if this edge existed, it would be part of the subgraph containing all edges with weights
 * less than or equal to the weight of edge e. It would also connect both components C1 and C2 that are connected
 * by edge e. However, e is a bridge and its removal would split components C1 and C2. So no such edge exists.
 * Therefore, edge e is critical.
 */
// O(E lg E)
public Queue<Edge> findCriticalEdges(EdgeWeightedGraph edgeWeightedGraph) {
    Queue<Edge> criticalEdges = new Queue<>();
    // Modified Kruskal's algorithm
    Queue<Edge> minimumSpanningTree = new Queue<>();
    PriorityQueueResize<Edge> priorityQueue = new PriorityQueueResize<>(PriorityQueueResize.Orientation.MIN);
    for (Edge edge : edgeWeightedGraph.edges()) {
        priorityQueue.insert(edge);
    }
    UnionFind unionFind = new UnionFind(edgeWeightedGraph.vertices());
    // Subgraph with components
    EdgeWeightedGraphWithDelete componentsSubGraph = new EdgeWeightedGraphWithDelete(unionFind.count());
    while (!priorityQueue.isEmpty() && minimumSpanningTree.size() < edgeWeightedGraph.vertices() - 1) {
        Edge edge = priorityQueue.deleteTop();
        int vertex1 = edge.either();
        int vertex2 = edge.other(vertex1);
        // Ineligible edges are never critical edges
        if (unionFind.connected(vertex1, vertex2)) {
            continue;
        }
        // Get next equal-weight edge block
        double currentWeight = edge.weight();
        HashSet<Edge> equalWeightEdges = new HashSet<>();
        equalWeightEdges.add(edge);
        while (!priorityQueue.isEmpty() && priorityQueue.peek().weight() == currentWeight) {
            equalWeightEdges.add(priorityQueue.deleteTop());
        }
        if (equalWeightEdges.size() == 1) {
            // There is no cycle, so this is a critical edge
            criticalEdges.enqueue(edge);
            unionFind.union(vertex1, vertex2);
            minimumSpanningTree.enqueue(edge);
            continue;
        }
        List<Edge> edgesToAddToComponentsSubGraph = new ArrayList<>();
        // Map to make the mapping between edges in the components subgraph and the original graph
        int averageMapListSize = Math.max(2, equalWeightEdges.size() / 20);
        SeparateChainingHashTable<Edge, Edge> subGraphToGraphEdgeMap = new SeparateChainingHashTable<>(equalWeightEdges.size(), averageMapListSize);
        HashSet<Integer> verticesInSubGraph = new HashSet<>();
        // Generate subgraph with the current components
        for (Edge edgeInCurrentBlock : equalWeightEdges.keys()) {
            vertex1 = edgeInCurrentBlock.either();
            vertex2 = edgeInCurrentBlock.other(vertex1);
            int component1 = unionFind.find(vertex1);
            int component2 = unionFind.find(vertex2);
            Edge subGraphEdge = new Edge(component1, component2, currentWeight);
            edgesToAddToComponentsSubGraph.add(subGraphEdge);
            subGraphToGraphEdgeMap.put(subGraphEdge, edgeInCurrentBlock);
            verticesInSubGraph.add(component1);
            verticesInSubGraph.add(component2);
        }
        for (Edge edgeToAddToComponentSubGraph : edgesToAddToComponentsSubGraph) {
            componentsSubGraph.addEdge(edgeToAddToComponentSubGraph);
        }
        // Run DFS to check if there is a cycle. Any edges in the cycle are non-critical.
        // Every edge in the original graph will be visited by a DFS at most once.
        HashSet<Edge> nonCriticalEdges = new HashSet<>();
        // Use a different constructor for EdgeWeightedCycle to avoid O(E * V) runtime
        EdgeWeightedCycle edgeWeightedCycle = new EdgeWeightedCycle(componentsSubGraph, verticesInSubGraph);
        if (edgeWeightedCycle.hasCycle()) {
            for (Edge edgeInCycle : edgeWeightedCycle.cycle()) {
                Edge edgeInGraph = subGraphToGraphEdgeMap.get(edgeInCycle);
                nonCriticalEdges.add(edgeInGraph);
            }
        }
        // Clear components subgraph edges
        for (Edge edgeToAddToComponentSubGraph : edgesToAddToComponentsSubGraph) {
            componentsSubGraph.deleteEdge(edgeToAddToComponentSubGraph);
        }
        // Add all edges that belong to an MST to the MST
        for (Edge edgeInCurrentBlock : equalWeightEdges.keys()) {
            if (!nonCriticalEdges.contains(edgeInCurrentBlock)) {
                criticalEdges.enqueue(edgeInCurrentBlock);
            }
            vertex1 = edgeInCurrentBlock.either();
            vertex2 = edgeInCurrentBlock.other(vertex1);
            if (!unionFind.connected(vertex1, vertex2)) {
                unionFind.union(vertex1, vertex2);
                // Add edge to the minimum spanning tree
                minimumSpanningTree.enqueue(edge);
            }
        }
    }
    return criticalEdges;
}

Example 22 with Queue

use of com.google.cloud.tasks.v2.Queue in project algorithms-sedgewick-wayne by reneargento.

the class Exercise44_WebCrawler method crawlWeb.

public void crawlWeb(String sourceWebPage) {
    // timeout connection after 500 milliseconds
    System.setProperty("sun.net.client.defaultConnectTimeout", "500");
    System.setProperty("sun.net.client.defaultReadTimeout", "1000");
    Queue<String> webPagesQueue = new Queue<>();
    webPagesQueue.enqueue(sourceWebPage);
    HashSet<String> visited = new HashSet<>();
    visited.add(sourceWebPage);
    while (!webPagesQueue.isEmpty()) {
        String currentWebPage = webPagesQueue.dequeue();
        String webPageContent;
        try {
            In in = new In(currentWebPage);
            webPageContent = in.readAll();
        } catch (IllegalArgumentException exception) {
            StdOut.println("Could not open " + currentWebPage);
            continue;
        }
        StdOut.println(currentWebPage + " crawled");
        /**
         ***********************************************************
         *  Find links of the form: http://xxx.yyy.zzz or https://xxx.yyy.zzz
         *  s? for either http or https
         *  \\w+ for one or more alpha-numeric characters
         *  \\. for dot
         ************************************************************
         */
        String regexp = "http(s?)://(\\w+\\.)+(\\w+)";
        Pattern pattern = Pattern.compile(regexp);
        Matcher matcher = pattern.matcher(webPageContent);
        // Find all matches
        while (matcher.find()) {
            String webPage = matcher.group();
            if (!visited.contains(webPage)) {
                webPagesQueue.enqueue(webPage);
                visited.add(webPage);
            }
        }
    }
}

Example 23 with Queue

use of com.google.cloud.tasks.v2.Queue in project java-docs-samples by GoogleCloudPlatform.

the class PurgeQueue method purgeQueue.

public static void purgeQueue(String projectId, String locationId, String queueId) throws Exception {
    try (CloudTasksClient client = CloudTasksClient.create()) {
        // TODO(developer): Uncomment these lines and replace with your values.
        // String projectId = "your-project-id";
        // String locationId = "us-central1";
        // String queueId = "foo";
        // Construct the fully qualified queue name.
        String queueName = QueueName.of(projectId, locationId, queueId).toString();
        client.purgeQueue(queueName);
        System.out.println("Queue Purged.");
    }
}

Example 24 with Queue

use of com.google.cloud.tasks.v2.Queue in project java-docs-samples by GoogleCloudPlatform.

the class CreateTask method main.

public static void main(String... args) throws Exception {
    Options options = new Options();
    options.addOption(PROJECT_ID_OPTION);
    options.addOption(QUEUE_OPTION);
    options.addOption(LOCATION_OPTION);
    options.addOption(PAYLOAD_OPTION);
    options.addOption(IN_SECONDS_OPTION);
    if (args.length == 0) {
        printUsage(options);
        return;
    }
    CommandLineParser parser = new DefaultParser();
    CommandLine params = null;
    try {
        params = parser.parse(options, args);
    } catch (ParseException e) {
        System.err.println("Invalid command line: " + e.getMessage());
        printUsage(options);
        return;
    }
    String projectId;
    if (params.hasOption("project-id")) {
        projectId = params.getOptionValue("project-id");
    } else {
        projectId = System.getenv(GOOGLE_CLOUD_PROJECT_KEY);
    }
    if (Strings.isNullOrEmpty(projectId)) {
        printUsage(options);
        return;
    }
    String queueName = params.getOptionValue(QUEUE_OPTION.getOpt());
    String location = params.getOptionValue(LOCATION_OPTION.getOpt());
    String payload = params.getOptionValue(PAYLOAD_OPTION.getOpt(), "default payload");
    // Instantiates a client.
    try (CloudTasksClient client = CloudTasksClient.create()) {
        // Variables provided by the CLI.
        // projectId = "my-project-id";
        // queueName = "my-appengine-queue";
        // location = "us-central1";
        // payload = "hello";
        // Construct the fully qualified queue name.
        String queuePath = QueueName.of(projectId, location, queueName).toString();
        // Construct the task body.
        Task.Builder taskBuilder = Task.newBuilder().setAppEngineHttpRequest(AppEngineHttpRequest.newBuilder().setBody(ByteString.copyFrom(payload, Charset.defaultCharset())).setRelativeUri("/tasks/create").setHttpMethod(HttpMethod.POST).build());
        if (params.hasOption(IN_SECONDS_OPTION.getOpt())) {
            // Add the scheduled time to the request.
            int seconds = Integer.parseInt(params.getOptionValue(IN_SECONDS_OPTION.getOpt()));
            taskBuilder.setScheduleTime(Timestamp.newBuilder().setSeconds(Instant.now(Clock.systemUTC()).plusSeconds(seconds).getEpochSecond()));
        }
        // Send create task request.
        Task task = client.createTask(queuePath, taskBuilder.build());
        System.out.println("Task created: " + task.getName());
    }
// [END cloud_tasks_appengine_create_task]
}

Example 25 with Queue

use of com.google.cloud.tasks.v2.Queue in project nomulus by google.

the class TldFanoutAction method run.

@Override
public void run() {
    checkArgument(!(runInEmpty && (forEachTestTld || forEachRealTld)), "runInEmpty and forEach*Tld are mutually exclusive");
    checkArgument(runInEmpty || forEachTestTld || forEachRealTld, "At least one of runInEmpty, forEachTestTld, forEachRealTld must be given");
    checkArgument(!(runInEmpty && !excludes.isEmpty()), "Can't specify 'exclude' with 'runInEmpty'");
    ImmutableSet<String> tlds = runInEmpty ? ImmutableSet.of("") : Streams.concat(forEachRealTld ? getTldsOfType(REAL).stream() : Stream.of(), forEachTestTld ? getTldsOfType(TEST).stream() : Stream.of()).filter(not(in(excludes))).collect(toImmutableSet());
    Multimap<String, String> flowThruParams = filterKeys(params, not(in(CONTROL_PARAMS)));
    StringBuilder outputPayload = new StringBuilder(String.format("OK: Launched the following %d tasks in queue %s\n", tlds.size(), queue));
    logger.atInfo().log("Launching %d tasks in queue %s.", tlds.size(), queue);
    if (tlds.isEmpty()) {
        logger.atWarning().log("No TLDs to fan-out!");
    }
    for (String tld : tlds) {
        Task task = createTask(tld, flowThruParams);
        Task createdTask = cloudTasksUtils.enqueue(queue, task);
        outputPayload.append(String.format("- Task: '%s', tld: '%s', endpoint: '%s'\n", createdTask.getName(), tld, createdTask.getAppEngineHttpRequest().getRelativeUri()));
        logger.atInfo().log("Task: '%s', tld: '%s', endpoint: '%s'.", createdTask.getName(), tld, createdTask.getAppEngineHttpRequest().getRelativeUri());
    }
    response.setContentType(PLAIN_TEXT_UTF_8);
    response.setPayload(outputPayload.toString());
}