com.google.common.collect.Iterables#limit ( )源码实例Demo

@Override
public SoyValue applyForJava(SoyValue value, List<SoyValue> args) {
  final String spacer = Strings.repeat(" ", args.get(0).integerValue());
  Iterable<String> pre;
  Iterable<String> toBeIndented;
  if (getIndentFirstArg(args)) {
    pre = ImmutableList.of();
    toBeIndented = SPLITTER.split(value.coerceToString());
  } else {
    List<String> lines = SPLITTER.splitToList(value.coerceToString());
    pre = Iterables.limit(lines, 1);
    toBeIndented = Iterables.skip(lines, 1);
  }
  Iterable<String> indented = Iterables.transform(toBeIndented, new Function<String, String>() {
    @Override
    public String apply(String s) {
      if (s.trim().isEmpty()) {
        // Don't indent lines with only spaces.
        return s;
      }
      return spacer + s;
    }
  });
  return StringData.forValue(JOINER.join(Iterables.concat(pre, indented)));
}
 

/**
 * Apply the sorting options to the given facet results.
 *
 * @param facetResults to apply sorting options to
 * @return the sorted results
 */
@SuppressWarnings({"unchecked", "rawtypes"})
protected Iterable<FacetBucket> applyOptions(List<FacetBucket> facetResults) {
  // Sorting the buckets if a sort specification is provided
  if (sort == null || facetResults.isEmpty()) {
    return facetResults;
  }
  Comparator comp = sort.getComparator();
  Collections.sort(facetResults, comp);

  Iterable<FacetBucket> facetResultsIter = facetResults;
  // apply the limit
  if (sort.getLimit() > 0) {
    if (sort.getOffset() > 0) {
      facetResultsIter = Iterables.skip(facetResultsIter, sort.getOffset());
    }
    facetResultsIter = Iterables.limit(facetResultsIter, sort.getLimit());
  } else if (sort.getLimit() == 0) {
    return new LinkedList<FacetBucket>();
  }
  return facetResultsIter;
}
 

/** Output JSON for a list of hosts. */
private NameserverSearchResponse makeSearchResults(
    List<HostResource> hosts,
    IncompletenessWarningType incompletenessWarningType,
    int numHostsRetrieved,
    CursorType cursorType) {
  metricInformationBuilder.setNumHostsRetrieved(numHostsRetrieved);
  OutputDataType outputDataType =
      (hosts.size() > 1) ? OutputDataType.SUMMARY : OutputDataType.FULL;
  NameserverSearchResponse.Builder builder =
      NameserverSearchResponse.builder().setIncompletenessWarningType(incompletenessWarningType);
  Optional<String> newCursor = Optional.empty();
  for (HostResource host : Iterables.limit(hosts, rdapResultSetMaxSize)) {
    newCursor =
        Optional.of((cursorType == CursorType.NAME) ? host.getHostName() : host.getRepoId());
    builder
        .nameserverSearchResultsBuilder()
        .add(rdapJsonFormatter.createRdapNameserver(host, outputDataType));
  }
  if (rdapResultSetMaxSize < hosts.size()) {
    builder.setNextPageUri(createNavigationUri(newCursor.get()));
    builder.setIncompletenessWarningType(IncompletenessWarningType.TRUNCATED);
  }
  return builder.build();
}
 

/**
 * Output JSON for a list of domains.
 *
 * <p>The incompletenessWarningType should be set to TRUNCATED if the search found more results
 * than are in the list, or MIGHT_BE_INCOMPLETE if a search for domains by nameserver returned the
 * maximum number of nameservers in the first stage query.
 */
private DomainSearchResponse makeSearchResults(
    List<DomainBase> domains,
    IncompletenessWarningType incompletenessWarningType,
    Optional<Long> numDomainsRetrieved) {
  numDomainsRetrieved.ifPresent(metricInformationBuilder::setNumDomainsRetrieved);
  OutputDataType outputDataType =
      (domains.size() > 1) ? OutputDataType.SUMMARY : OutputDataType.FULL;
  DomainSearchResponse.Builder builder =
      DomainSearchResponse.builder()
          .setIncompletenessWarningType(incompletenessWarningType);
  Optional<String> newCursor = Optional.empty();
  for (DomainBase domain : Iterables.limit(domains, rdapResultSetMaxSize)) {
    newCursor = Optional.of(domain.getDomainName());
    builder
        .domainSearchResultsBuilder()
        .add(rdapJsonFormatter.createRdapDomain(domain, outputDataType));
  }
  if (rdapResultSetMaxSize < domains.size()) {
    builder.setNextPageUri(createNavigationUri(newCursor.get()));
    builder.setIncompletenessWarningType(IncompletenessWarningType.TRUNCATED);
  }
  return builder.build();
}
 

private static void printWorkingSet(BlazeContext context, WorkingSet workingSet) {
  List<String> messages = Lists.newArrayList();
  messages.addAll(
      workingSet.addedFiles.stream()
          .map(file -> file.relativePath() + " (added)")
          .collect(Collectors.toList()));
  messages.addAll(
      workingSet.modifiedFiles.stream()
          .map(file -> file.relativePath() + " (modified)")
          .collect(Collectors.toList()));
  Collections.sort(messages);

  if (messages.isEmpty()) {
    context.output(PrintOutput.log("Your working set is empty"));
    return;
  }
  int maxFiles = 20;
  for (String message : Iterables.limit(messages, maxFiles)) {
    context.output(PrintOutput.log("  " + message));
  }
  if (messages.size() > maxFiles) {
    context.output(PrintOutput.log(String.format("  (and %d more)", messages.size() - maxFiles)));
  }
  context.output(PrintOutput.output(""));
}
 

/**
 * Returns an iterable that skips forward to a given notification ID then only returns count more
 * notifications. If the given notification ID is not found
 *
 * @param notifications Iterable of notifications
 * @param startId notification ID to start at
 * @param inclusive Whether to include the startId notification or not
 * @param limitSize Number of notifications to return
 * @return Iterable containing the subset of the original notifications
 */
public Iterable<Notification> skip(
    final Iterable<Notification> notifications,
    final String startId,
    final boolean inclusive,
    final int limitSize) {

  Objects.requireNonNull(notifications, "notifications == null");

  final int position = indexOf(notifications, startId);
  if (position == -1) {
    return Iterables.limit(notifications, limitSize);
  }
  if (inclusive) {
    return Iterables.limit(Iterables.skip(notifications, position), limitSize);
  }
  return Iterables.limit(Iterables.skip(notifications, position + 1), limitSize);
}
 

private static void deepDumpInternal(Object o, Predicate<Field> fieldPredicate, PrintStream out, int indentSize, String prefix, List<Object> visited) throws IllegalArgumentException, IllegalAccessException {
    String indent = com.google.common.base.Strings.repeat(" ", indentSize*2);
    Class<?> clazz = (o != null) ? o.getClass() : null;
    
    if (o == null) {
        out.println(indent+prefix+"null");
    } else if (isClassUntraversable(clazz)) {
        out.println(indent+prefix+"(untraversable) type="+clazz+"; val="+o.toString());
    } else if (containsSame(visited, o)) {
        out.println(indent+prefix+"duplicate (type="+clazz+"; val="+o.toString()+")");
    } else {
        visited.add(o);
        out.println(indent+prefix+"type="+clazz+"; val="+o.toString());
        Map<String, Object> members = findMembers(o, fieldPredicate);
        for (Map.Entry<String, Object> entry : Iterables.limit(members.entrySet(), MAX_MEMBERS)) {
            deepDumpInternal(entry.getValue(), fieldPredicate, out, indentSize+1, ""+entry.getKey()+": ", visited);
        }
        if (members.size() > MAX_MEMBERS) {
            out.println(indent+prefix+"TRUNCATED ("+members.size()+" members in total)");
        }
    }
}
 

private List<ScheduledTask> getTasks(TaskQuery query) {
  requireNonNull(query);

  Iterable<IScheduledTask> tasks = Storage.Util.fetchTasks(storage, Query.arbitrary(query));
  if (query.getOffset() > 0) {
    tasks = Iterables.skip(tasks, query.getOffset());
  }
  if (query.getLimit() > 0) {
    tasks = Iterables.limit(tasks, query.getLimit());
  }

  return IScheduledTask.toBuildersList(tasks);
}
 

public String getResultsComparison(int precision)
{
    List<List<Object>> controlResults = controlResult.getResults();
    List<List<Object>> testResults = testResult.getResults();

    if (valid() || (controlResults == null) || (testResults == null)) {
        return "";
    }

    Multiset<List<Object>> control = ImmutableSortedMultiset.copyOf(rowComparator(precision), controlResults);
    Multiset<List<Object>> test = ImmutableSortedMultiset.copyOf(rowComparator(precision), testResults);

    try {
        Iterable<ChangedRow> diff = ImmutableSortedMultiset.<ChangedRow>naturalOrder()
                .addAll(Iterables.transform(Multisets.difference(control, test), row -> new ChangedRow(Changed.REMOVED, row, precision)))
                .addAll(Iterables.transform(Multisets.difference(test, control), row -> new ChangedRow(Changed.ADDED, row, precision)))
                .build();
        diff = Iterables.limit(diff, 100);

        StringBuilder sb = new StringBuilder();

        sb.append(format("Control %s rows, Test %s rows%n", control.size(), test.size()));
        if (verboseResultsComparison) {
            Joiner.on("\n").appendTo(sb, diff);
        }
        else {
            sb.append("RESULTS DO NOT MATCH\n");
        }

        return sb.toString();
    }
    catch (TypesDoNotMatchException e) {
        return e.getMessage();
    }
}
 

@Override
public List<Contingency> getContingencies(Network network) {
    List<Contingency> contingencies = new ArrayList<>(lineContigencyCount);
    for (Line l : Iterables.limit(network.getLines(), lineContigencyCount)) {
        contingencies.add(new Contingency(l.getId(), Arrays.<ContingencyElement>asList(new BranchContingency(l.getId()))));
    }
    return contingencies;
}
 

@Override
public Response pruneTasks(TaskQuery query) throws TException {
  if (query.isSetStatuses() && query.getStatuses().stream().anyMatch(ACTIVE_STATES::contains)) {
    return error("Tasks in non-terminal state cannot be pruned.");
  } else if (!query.isSetStatuses()) {
    query.setStatuses(TERMINAL_STATES);
  }

  Iterable<IScheduledTask> tasks = storage.read(storeProvider ->
      storeProvider.getTaskStore().fetchTasks(Query.arbitrary(query)));
  // For some reason fetchTasks ignores the offset/limit options of a TaskQuery. So we have to
  // manually apply the limit here. To be fixed in AURORA-1892.
  if (query.isSetLimit()) {
    tasks = Iterables.limit(tasks, query.getLimit());
  }

  Iterable<String> taskIds = Iterables.transform(
      tasks,
      task -> task.getAssignedTask().getTaskId());

  return storage.write(storeProvider -> {
    Set<String> taskIdsSet = Sets.newHashSet(taskIds);
    stateManager.deleteTasks(storeProvider, taskIdsSet);
    pruneTasksCounter.addAndGet(taskIdsSet.size());
    return ok();
  });
}
 

private static Iterable<Map.Entry<byte[], byte[]>> readPcaps(Path pcapFile, boolean withHeaders) throws IOException {
  SequenceFile.Reader reader = new SequenceFile.Reader(new Configuration(),
      SequenceFile.Reader.file(pcapFile)
  );
  List<Map.Entry<byte[], byte[]> > ret = new ArrayList<>();
  IntWritable key = new IntWritable();
  BytesWritable value = new BytesWritable();
  while (reader.next(key, value)) {
    byte[] pcapWithHeader = value.copyBytes();
    //if you are debugging and want the hex dump of the packets, uncomment the following:

    //for(byte b : pcapWithHeader) {
    //  System.out.print(String.format("%02x", b));
    //}
    //System.out.println("");

    long calculatedTs = PcapHelper.getTimestamp(pcapWithHeader);
    {
      List<PacketInfo> info = PcapHelper.toPacketInfo(pcapWithHeader);
      for (PacketInfo pi : info) {
        assertEquals(calculatedTs, pi.getPacketTimeInNanos());
        //IF you are debugging and want to see the packets, uncomment the following.
        //System.out.println( Long.toUnsignedString(calculatedTs) + " => " + pi.getJsonDoc());
      }
    }
    if (withHeaders) {
      ret.add(new AbstractMap.SimpleImmutableEntry<>(Bytes.toBytes(calculatedTs), pcapWithHeader));
    } else {
      byte[] pcapRaw = new byte[pcapWithHeader.length - PcapHelper.GLOBAL_HEADER_SIZE - PcapHelper.PACKET_HEADER_SIZE];
      System.arraycopy(pcapWithHeader, PcapHelper.GLOBAL_HEADER_SIZE + PcapHelper.PACKET_HEADER_SIZE, pcapRaw, 0, pcapRaw.length);
      ret.add(new AbstractMap.SimpleImmutableEntry<>(Bytes.toBytes(calculatedTs), pcapRaw));
    }
  }
  return Iterables.limit(ret, 2 * (ret.size() / 2));
}
 

@Override
public Iterator<MailboxMessage> findInMailbox(Mailbox mailbox, MessageRange set,
                                                      org.apache.james.mailbox.store.mail.MessageMapper.FetchType type, int limit)
        throws MailboxException {
    
    List<MailboxMessage> messages = new ArrayList<>();
    for (MessageUid uid: Iterables.limit(set, limit)) {
        if (messageRange.includes(uid)) {
            messages.add(createMessage(uid));
        }    
    }
    return messages.iterator();
}
 

protected void runUsesInitialLocationsForExistingChildren(int numChildren) throws Exception {
    List<TestEntity> existingChildren = Lists.newArrayList();
    for (int i = 0; i < numChildren; i++) {
        existingChildren.add(fabric.addChild(EntitySpec.create(TestEntity.class)));
    }
    app.start(ImmutableList.of(loc1, loc2));

    int expectedNumChildren = Math.max(numChildren, 2);
    Iterable<Location> expectedChildLocations = Iterables.limit(Iterables.cycle(ImmutableList.of(loc1, loc2)), expectedNumChildren);
    
    assertFabricChildren(fabric, expectedNumChildren, ImmutableList.copyOf(expectedChildLocations));
    assertTrue(fabric.getChildren().containsAll(existingChildren));
}
 

@Override
public Iterable<Experiment> find(Filter filter, Experiment.BuilderFactory factory) {
    final List<Experiment> result = Lists.newArrayList();

    for (final Experiment experiment : db.values()) {
        if (filterMatches(
            filter.getFilter(),
            experiment.getName(),
            experiment.getDescription())) {
            result.add(Experiment.copyOf(experiment));
        }
    }

    if (filter.getOrdering() != null && !filter.getOrdering().isEmpty()) {
        final Comparator<Experiment> comparator = new OrderingComparator(filter.getOrdering());
        Collections.sort(result, comparator);
    }

    Iterable<Experiment> filteredResult = result;

    if (filter.getOffset() != null) {
        filteredResult = Iterables.skip(filteredResult, filter.getOffset());
    }

    if (filter.getLimit() != null) {
        filteredResult = Iterables.limit(filteredResult, filter.getLimit());
    }

    return Lists.newArrayList(filteredResult);
}
 

private static void logDiffInfo(
    Iterable<Root> pathEntries,
    Iterable<SkyKey> changedWithoutNewValue,
    int numWithoutNewValues,
    Map<SkyKey, ? extends SkyValue> changedWithNewValue) {
  int numModified = changedWithNewValue.size() + numWithoutNewValues;
  StringBuilder result = new StringBuilder("DiffAwareness found ")
      .append(numModified)
      .append(" modified source files and directory listings");
  if (!Iterables.isEmpty(pathEntries)) {
    result.append(" for ");
    result.append(Joiner.on(", ").join(pathEntries));
  }

  if (numModified > 0) {
    Iterable<SkyKey> allModifiedKeys = Iterables.concat(changedWithoutNewValue,
        changedWithNewValue.keySet());
    Iterable<SkyKey> trimmed =
        Iterables.limit(allModifiedKeys, MAX_NUMBER_OF_CHANGED_KEYS_TO_LOG);

    result.append(": ")
        .append(Joiner.on(", ").join(trimmed));

    if (numModified > MAX_NUMBER_OF_CHANGED_KEYS_TO_LOG) {
      result.append(", ...");
    }
  }

  logger.atInfo().log(result.toString());
}
 

private String makeErrorMessageForNotHavingASingleTarget(
    String targetPatternString, Iterable<String> expandedTargetNames) {
  final int maxNumExpandedTargetsToIncludeInErrorMessage = 5;
  boolean truncateTargetNameList = Iterables.size(expandedTargetNames) > 5;
  Iterable<String> targetNamesToIncludeInErrorMessage =
      truncateTargetNameList
          ? Iterables.limit(expandedTargetNames, maxNumExpandedTargetsToIncludeInErrorMessage)
          : expandedTargetNames;
  return String.format(
      "Only a single target can be run. Your target pattern %s expanded to the targets %s%s",
      targetPatternString,
      Joiner.on(", ").join(ImmutableSortedSet.copyOf(targetNamesToIncludeInErrorMessage)),
      truncateTargetNameList ? "[TRUNCATED]" : "");
}
 

private String getConditionsGraphLabel(
    Iterable<Node<Target>> lhs, Iterable<Node<Target>> rhs, ConditionalEdges conditionalEdges) {
  StringBuilder buf = new StringBuilder();

  if (this.graphConditionalEdgesLimit == 0) {
    return buf.toString();
  }

  Set<Label> annotatedLabels = new HashSet<>();
  for (Node<Target> src : lhs) {
    Label srcLabel = src.getLabel().getLabel();
    for (Node<Target> dest : rhs) {
      Label destLabel = dest.getLabel().getLabel();
      Optional<Set<Label>> conditions = conditionalEdges.get(srcLabel, destLabel);
      if (conditions.isPresent()) {
        boolean firstItem = true;

        int limit =
            (this.graphConditionalEdgesLimit == -1)
                ? conditions.get().size()
                : (this.graphConditionalEdgesLimit - 1);

        for (Label conditionLabel : Iterables.limit(conditions.get(), limit)) {
          if (!annotatedLabels.add(conditionLabel)) {
            // duplicate label; skip.
            continue;
          }

          if (!firstItem) {
            buf.append("\\n");
          }

          buf.append(conditionLabel.getCanonicalForm());
          firstItem = false;
        }
        if (conditions.get().size() > limit) {
          buf.append("...");
        }
      }
    }
  }
  return buf.toString();
}
 

@Override
protected List<Map<String, AttributeValue>> getFinalItemList() {
    final Iterable<Map<String, AttributeValue>> limitedIter = Iterables.limit(super.getFinalItemList(), limit);
    return Lists.newArrayList(limitedIter);
}
 

/** Pretty print action diffs (at most {@code MAX_DIFF_ARTIFACTS_TO_REPORT} lines). */
private static void prettyPrintArtifactDiffs(StringBuilder sb, Set<Artifact> diff) {
  for (Artifact artifact : Iterables.limit(diff, MAX_DIFF_ARTIFACTS_TO_REPORT)) {
    sb.append("\t" + artifact.prettyPrint() + "\n");
  }
}