com.google.common.collect.Maps.newHashMapWithExpectedSize()方法的使用及代码示例

x33g5p2x  于2022-01-24 转载在 其他  
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本文整理了Java中com.google.common.collect.Maps.newHashMapWithExpectedSize()方法的一些代码示例，展示了Maps.newHashMapWithExpectedSize()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。Maps.newHashMapWithExpectedSize()方法的具体详情如下：
包路径：com.google.common.collect.Maps
类名称：Maps
方法名：newHashMapWithExpectedSize

Maps.newHashMapWithExpectedSize介绍

[英]Creates a HashMap instance, with a high enough "initial capacity" that it should hold expectedSize elements without growth. This behavior cannot be broadly guaranteed, but it is observed to be true for OpenJDK 1.6. It also can't be guaranteed that the method isn't inadvertently oversizing the returned map.
[中]创建一个HashMap实例，该实例具有足够高的“初始容量”，可以容纳expectedSize元素而不会增长。这种行为不能得到广泛的保证，但OpenJDK1.6的情况确实如此。也不能保证该方法不会无意中过度调整返回的映射。

代码示例

代码示例来源：origin: Graylog2/graylog2-server

public LenientExplicitOrdering(List<T> order) {
  this.idxMap = Maps.newHashMapWithExpectedSize(order.size());
  int idx = 0;
  for (T s : order) {
    idxMap.put(s, idx);
    idx++;
  }
}

代码示例来源：origin: voldemort/voldemort

public Map<Integer, Long> asMap() {
  Map<Integer, Long> map = Maps.newHashMapWithExpectedSize(values.size());
  for(Map.Entry<Integer, AtomicLong> entry: values.entrySet())
    map.put(entry.getKey(), entry.getValue().get());
  return Collections.unmodifiableMap(map);
}

代码示例来源：origin: alibaba/jstorm

public static Map<Integer, MetricSnapshot> toThriftGaugeSnapshots(Map<Integer, AsmSnapshot> snapshots) {
  Map<Integer, MetricSnapshot> ret = Maps.newHashMapWithExpectedSize(snapshots.size());
  for (Map.Entry<Integer, AsmSnapshot> entry : snapshots.entrySet()) {
    ret.put(entry.getKey(), convert((AsmGaugeSnapshot) entry.getValue()));
  }
  return ret;
}

代码示例来源：origin: voldemort/voldemort

@Override
public Map<K, List<Versioned<V>>> getAll(Iterable<K> keys, Map<K, T> transforms)
    throws VoldemortException {
  StoreUtils.assertValidKeys(keys);
  Map<ByteArray, K> byteKeyToKey = keysToBytes(keys);
  Map<ByteArray, List<Versioned<byte[]>>> storeResult = store.getAll(byteKeyToKey.keySet(),
                                    transformsToBytes(transforms));
  Map<K, List<Versioned<V>>> result = Maps.newHashMapWithExpectedSize(storeResult.size());
  for(Map.Entry<ByteArray, List<Versioned<byte[]>>> mapEntry: storeResult.entrySet()) {
    List<Versioned<V>> values = Lists.newArrayListWithExpectedSize(mapEntry.getValue()
                                        .size());
    for(Versioned<byte[]> versioned: mapEntry.getValue())
      values.add(new Versioned<V>(valueSerializer.toObject(versioned.getValue()),
                    versioned.getVersion()));
    result.put(byteKeyToKey.get(mapEntry.getKey()), values);
  }
  return result;
}

代码示例来源：origin: apache/incubator-gobblin

this.avgMillisPerRecord = Maps.newHashMapWithExpectedSize(this.partitions.size());
this.avgRecordSizes = Maps.newHashMapWithExpectedSize(this.partitions.size());
this.elapsedTime = Maps.newHashMapWithExpectedSize(this.partitions.size());
this.processedRecordCount = Maps.newHashMapWithExpectedSize(this.partitions.size());
this.partitionTotalSize = Maps.newHashMapWithExpectedSize(this.partitions.size());
this.decodeRecordTime = Maps.newHashMapWithExpectedSize(this.partitions.size());
this.fetchMessageBufferTime = Maps.newHashMapWithExpectedSize(this.partitions.size());
this.readRecordTime = Maps.newHashMapWithExpectedSize(this.partitions.size());
this.startFetchEpochTime = Maps.newHashMapWithExpectedSize(this.partitions.size());
this.stopFetchEpochTime= Maps.newHashMapWithExpectedSize(this.partitions.size());

代码示例来源：origin: alibaba/jstorm

public static Map<Integer, MetricSnapshot> toThriftHistoSnapshots(MetaType metaType, Map<Integer, AsmSnapshot> snapshots) {
  Map<Integer, MetricSnapshot> ret = Maps.newHashMapWithExpectedSize(snapshots.size());
  for (Map.Entry<Integer, AsmSnapshot> entry : snapshots.entrySet()) {
    MetricSnapshot histogramSnapshot = convert(metaType, (AsmHistogramSnapshot) entry.getValue());
    if (histogramSnapshot != null) {
      ret.put(entry.getKey(), histogramSnapshot);
    }
  }
  return ret;
}

代码示例来源：origin: voldemort/voldemort

public RebalancerState(List<RebalanceTaskInfo> stealInfoList) {
  stealInfoMap = Maps.newHashMapWithExpectedSize(stealInfoList.size());
  for(RebalanceTaskInfo rebalanceTaskInfo: stealInfoList)
    stealInfoMap.put(rebalanceTaskInfo.getDonorId(), rebalanceTaskInfo);
}

代码示例来源：origin: googleapis/google-cloud-java

private static List<Entity> compileEntities(Key[] keys, Iterator<Entity> entities) {
  Map<Key, Entity> map = Maps.newHashMapWithExpectedSize(keys.length);
  while (entities.hasNext()) {
   Entity entity = entities.next();
   map.put(entity.getKey(), entity);
  }
  List<Entity> list = new ArrayList<>(keys.length);
  for (Key key : keys) {
   // this will include nulls for nonexistent keys
   list.add(map.get(key));
  }
  return list;
 }
}

代码示例来源：origin: apache/kylin

List<RexNode> newExpList = Lists.newLinkedList();
Map<Integer, Pair<RelDataTypeField, RexNode>> replaceFieldMap = Maps
    .newHashMapWithExpectedSize(this.context.dynamicFields.size());
int paramIndex = this.rowType.getFieldList().size();
for (Map.Entry<String, RelDataType> rewriteField : this.context.rewriteFields.entrySet()) {
  String rewriteFieldName = rewriteField.getKey();
  int rowIndex = this.columnRowType.getIndexByName(rewriteFieldName);
      RexInputRef newFieldRef = new RexInputRef(inputField.getIndex(), inputField.getType());
      replaceFieldMap.put(rowIndex, new Pair<RelDataTypeField, RexNode>(newField, newFieldRef));

代码示例来源：origin: alibaba/jstorm

public static Map<Integer, MetricSnapshot> toThriftCounterSnapshots(Map<Integer, AsmSnapshot> snapshots) {
  Map<Integer, MetricSnapshot> ret = Maps.newHashMapWithExpectedSize(snapshots.size());
  for (Map.Entry<Integer, AsmSnapshot> entry : snapshots.entrySet()) {
    ret.put(entry.getKey(), convert((AsmCounterSnapshot) entry.getValue()));
  }
  return ret;
}

代码示例来源：origin: immutables/immutables

DictionaryAidedDepluralizer(String[] exceptions) {
 Map<String, String> map = Maps.newHashMapWithExpectedSize(exceptions.length);
 Splitter splitter = Splitter.on(':');
 for (String s : exceptions) {
  List<String> parts = splitter.splitToList(s.toLowerCase());
  if (parts.size() == 1) {
   // simple no-depluratization exception
   map.put(parts.get(0), parts.get(0));
  } else if (parts.size() == 2) {
   // singular, then plural, so mapping plural->singular
   map.put(parts.get(1), parts.get(0));
  }
 }
 this.dictionary = ImmutableMap.copyOf(map);
}

代码示例来源：origin: Graylog2/graylog2-server

public Map<String, String> getQueryParams() {
  if (queryMap == null) {
    final Map<String, String> queryMap = Maps.newHashMapWithExpectedSize(url.querySize());
    for(String name : url.queryParameterNames()) {
      final List<String> values = url.queryParameterValues(name);
      final String valueString = Joiner.on(',').join(values);
      queryMap.put(name, valueString);
    }
    this.queryMap = queryMap;
  }
  return queryMap;
}

代码示例来源：origin: alibaba/jstorm

public static Map<Integer, MetricSnapshot> toThriftMeterSnapshots(Map<Integer, AsmSnapshot> snapshots) {
  Map<Integer, MetricSnapshot> ret = Maps.newHashMapWithExpectedSize(snapshots.size());
  for (Map.Entry<Integer, AsmSnapshot> entry : snapshots.entrySet()) {
    ret.put(entry.getKey(), convert((AsmMeterSnapshot) entry.getValue()));
  }
  return ret;
}

代码示例来源：origin: qunarcorp/qmq

public BrokerClusterInfo(List<BrokerGroupInfo> groupList) {
  this.groupList = groupList;
  this.groupMap = Maps.newHashMapWithExpectedSize(groupList.size());
  for (BrokerGroupInfo group : groupList) {
    groupMap.put(group.getGroupName(), group);
  }
}

代码示例来源：origin: apache/kylin

/**
 * adjust cuboid row count, make sure parent not less than child
 */
public static Map<Long, Long> adjustCuboidStats(Map<Long, Long> statistics) {
  Map<Long, Long> ret = Maps.newHashMapWithExpectedSize(statistics.size());
  List<Long> cuboids = Lists.newArrayList(statistics.keySet());
  Collections.sort(cuboids);
  for (Long cuboid : cuboids) {
    Long rowCount = statistics.get(cuboid);
    for (Long childCuboid : ret.keySet()) {
      if (isDescendant(childCuboid, cuboid)) {
        Long childRowCount = ret.get(childCuboid);
        if (rowCount < childRowCount) {
          rowCount = childRowCount;
        }
      }
    }
    ret.put(cuboid, rowCount);
  }
  return ret;
}

代码示例来源：origin: alibaba/jstorm

public static Map<Integer, MetricSnapshot> toThriftHistoSnapshots(Map<Integer, AsmSnapshot> snapshots) {
  Map<Integer, MetricSnapshot> ret = Maps.newHashMapWithExpectedSize(snapshots.size());
  for (Map.Entry<Integer, AsmSnapshot> entry : snapshots.entrySet()) {
    MetricSnapshot histogramSnapshot = convert((AsmHistogramSnapshot) entry.getValue());
    if (histogramSnapshot != null) {
      ret.put(entry.getKey(), histogramSnapshot);
    }
  }
  return ret;
}

代码示例来源：origin: voldemort/voldemort

/**
 * Returns the 'current' version of RO store
 * 
 * @param nodeId The id of the node on which the store is present
 * @param storeNames List of all the stores
 * @return Returns a map of store name to the respective max version
 *         number
 */
public Map<String, Long> getROCurrentVersion(int nodeId, List<String> storeNames) {
  Map<String, Long> returnMap = Maps.newHashMapWithExpectedSize(storeNames.size());
  Map<String, String> versionDirs = getROCurrentVersionDir(nodeId, storeNames);
  for(String storeName: versionDirs.keySet()) {
    returnMap.put(storeName,
           ReadOnlyUtils.getVersionId(new File(versionDirs.get(storeName))));
  }
  return returnMap;
}

代码示例来源：origin: google/guava

static <E> ImmutableMultiset<E> create(Collection<? extends Entry<? extends E>> entries) {
 @SuppressWarnings("unchecked")
 Entry<E>[] entriesArray = entries.toArray(new Entry[0]);
 Map<E, Integer> delegateMap = Maps.newHashMapWithExpectedSize(entriesArray.length);
 long size = 0;
 for (int i = 0; i < entriesArray.length; i++) {
  Entry<E> entry = entriesArray[i];
  int count = entry.getCount();
  size += count;
  E element = checkNotNull(entry.getElement());
  delegateMap.put(element, count);
  if (!(entry instanceof Multisets.ImmutableEntry)) {
   entriesArray[i] = Multisets.immutableEntry(element, count);
  }
 }
 return new JdkBackedImmutableMultiset<>(
   delegateMap, ImmutableList.asImmutableList(entriesArray), size);
}

代码示例来源：origin: voldemort/voldemort

@Override
public Map<K, Versioned<V>> getAll(Iterable<K> keys, Map<K, Object> transforms) {
  Map<K, List<Versioned<V>>> items = null;
  items = this.clientStore.getAll(keys, null);
  Map<K, Versioned<V>> result = Maps.newHashMapWithExpectedSize(items.size());
  for(Entry<K, List<Versioned<V>>> mapEntry: items.entrySet()) {
    Versioned<V> value = getItemOrThrow(mapEntry.getKey(), null, mapEntry.getValue());
    result.put(mapEntry.getKey(), value);
  }
  return result;
}

代码示例来源：origin: voldemort/voldemort

/**
 * Returns the max version of push currently being used by read-only
 * store. Important to remember that this may not be the 'current'
 * version since multiple pushes (with greater version numbers) may be
 * in progress currently
 * 
 * @param nodeId The id of the node on which the store is present
 * @param storeNames List of all the stores
 * @return Returns a map of store name to the respective max version
 *         number
 */
public Map<String, Long> getROMaxVersion(int nodeId, List<String> storeNames) {
  Map<String, Long> returnMap = Maps.newHashMapWithExpectedSize(storeNames.size());
  Map<String, String> versionDirs = getROMaxVersionDir(nodeId, storeNames);
  for(String storeName: versionDirs.keySet()) {
    returnMap.put(storeName,
           ReadOnlyUtils.getVersionId(new File(versionDirs.get(storeName))));
  }
  return returnMap;
}

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