private long aggregateForEntries(Aggregate aggr) {
    AvlNode<E> root = rootReference.get();
    long total = aggr.treeAggregate(root);
    if (range.hasLowerBound()) {
      total -= aggregateBelowRange(aggr, root);
    }
    if (range.hasUpperBound()) {
      total -= aggregateAboveRange(aggr, root);
    }
    return total;
  }

  private long aggregateBelowRange(Aggregate aggr, @Nullable AvlNode<E> node) {

    // GET /api/admin/backup/files
    @Execute
    public JsonResponse<ApiResult> files() {
        final List<Map<String, String>> list = getBackupItems();
        return asJson(new ApiBackupFilesResponse().files(list).total(list.size()).status(ApiResult.Status.OK).result());
    }

    /**
     * Downloads a specific backup file by ID.
     * Supports various backup formats including system properties, bulk data, and NDJSON logs.
     *

    // We are going to take the project packaging and find all plugin in the default lifecycle and create
    // fully populated Plugin objects, including executions with goals and default configuration taken
    // from the plugin.xml inside a plugin.
    //
    // TODO This whole method could probably removed by injecting lifeCyclePluginAnalyzer straight into client site.

   * c}}.
   *
   * @param arrays zero or more {@code float} arrays
   * @return a single array containing all the values from the source arrays, in order
   * @throws IllegalArgumentException if the total number of elements in {@code arrays} does not fit
   *     in an {@code int}
   */
  public static float[] concat(float[]... arrays) {
    long length = 0;
    for (float[] array : arrays) {

    }

    int readFsFullSizeInformationWireFormat(final byte[] buffer, int bufferIndex) {
        final int start = bufferIndex;

        final SmbInfoAllocation info = new SmbInfoAllocation();

        // Read total allocation units.
        info.alloc = readInt8(buffer, bufferIndex);
        bufferIndex += 8;

        // read caller available allocation units
        info.free = readInt8(buffer, bufferIndex);

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.cling.invoker.mvnup.goals;

import java.nio.file.Files;
import java.nio.file.Path;

import org.apache.maven.cling.invoker.mvnup.UpgradeContext;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;

			Status: ps.Info.Status.String(),
			Used:   float64(diskStats[i].TotalSpace-diskStats[i].AvailableSpace) / float64(diskStats[i].TotalSpace),
		}
		if !ps.Participating {
			continue
		}
		// for participating pools, total bytes to be rebalanced by this pool is given by,
		// pf_c = (f_i + x)/c_i,
		// pf_c - percentage free space across pools, f_i - ith pool's free space, c_i - ith pool's capacity
		// i.e. x = c_i*pfc -f_i

            assertArrayEquals(testFileId, actualFileId);

            // Verify that info.encode was called
            verify(mockInfo, times(1)).encode(any(byte[].class), anyInt());

            // Verify total bytes written
            assertTrue(bytesWritten > 32); // At least the fixed part plus some info
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

API 应用调用外部 API 时的流程叫做**回调**。因为外部开发者编写的软件发送请求至您的 API，然后您的 API 要进行回调，并把请求发送至外部 API。

此时，我们需要存档外部 API 的*信息*，比如应该有哪些*路径操作*，返回什么样的请求体，应该返回哪种响应等。

## 使用回调的应用

示例如下。

假设要开发一个创建发票的应用。

发票包括 `id`、`title`（可选）、`customer`、`total` 等属性。

API 的用户 （外部开发者）要在您的 API 内使用 POST 请求创建一条发票记录。

（假设）您的 API 将：

* 把发票发送至外部开发者的消费者
* 归集现金
* 把通知发送至 API 的用户（外部开发者）
    * 通过（从您的 API）发送 POST 请求至外部 API （即**回调**）来完成

## 常规 **FastAPI** 应用

// disk usage per path.
// The above means that any added/deleted fields are incompatible.
//
// The above means that any added/deleted fields are incompatible.
//
//msgp:tuple DiskInfo
type DiskInfo struct {
	Total      uint64
	Free       uint64
	Used       uint64
	UsedInodes uint64
	FreeInodes uint64
	Major      uint32
	Minor      uint32
	NRRequests uint64
	FSType     string
	RootDisk   bool
	Healing    bool