org.apache.hadoop.fs.StorageStatistics Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.fs;
import org.apache.hadoop.classification.InterfaceAudience;
import java.util.Iterator;
/**
* StorageStatistics contains statistics data for a FileSystem or FileContext
* instance.
*/
@InterfaceAudience.Public
public abstract class StorageStatistics {
/**
* These are common statistic names.
*
* The following names are considered general and preserved across different
* StorageStatistics classes. When implementing a new StorageStatistics, it is
* highly recommended to use the common statistic names.
*
* When adding new common statistic name constants, please make them unique.
* By convention, they are implicitly unique:
* - the name of the constants are uppercase, words separated by underscores.
* - the value of the constants are lowercase of the constant names.
*/
public interface CommonStatisticNames {
// The following names are for file system operation invocations
String OP_APPEND = "op_append";
String OP_COPY_FROM_LOCAL_FILE = "op_copy_from_local_file";
String OP_CREATE = "op_create";
String OP_CREATE_NON_RECURSIVE = "op_create_non_recursive";
String OP_DELETE = "op_delete";
String OP_EXISTS = "op_exists";
String OP_GET_CONTENT_SUMMARY = "op_get_content_summary";
String OP_GET_FILE_CHECKSUM = "op_get_file_checksum";
String OP_GET_FILE_STATUS = "op_get_file_status";
String OP_GET_STATUS = "op_get_status";
String OP_GLOB_STATUS = "op_glob_status";
String OP_IS_FILE = "op_is_file";
String OP_IS_DIRECTORY = "op_is_directory";
String OP_LIST_FILES = "op_list_files";
String OP_LIST_LOCATED_STATUS = "op_list_located_status";
String OP_LIST_STATUS = "op_list_status";
String OP_MKDIRS = "op_mkdirs";
String OP_MODIFY_ACL_ENTRIES = "op_modify_acl_entries";
String OP_OPEN = "op_open";
String OP_REMOVE_ACL = "op_remove_acl";
String OP_REMOVE_ACL_ENTRIES = "op_remove_acl_entries";
String OP_REMOVE_DEFAULT_ACL = "op_remove_default_acl";
String OP_RENAME = "op_rename";
String OP_SET_ACL = "op_set_acl";
String OP_SET_OWNER = "op_set_owner";
String OP_SET_PERMISSION = "op_set_permission";
String OP_SET_TIMES = "op_set_times";
String OP_TRUNCATE = "op_truncate";
}
/**
* A 64-bit storage statistic.
*/
public static class LongStatistic {
private final String name;
private final long value;
public LongStatistic(String name, long value) {
this.name = name;
this.value = value;
}
/**
* @return The name of this statistic.
*/
public String getName() {
return name;
}
/**
* @return The value of this statistic.
*/
public long getValue() {
return value;
}
@Override
public String toString() {
return name + " = " + value;
}
}
private final String name;
public StorageStatistics(String name) {
this.name = name;
}
/**
* Get the name of this StorageStatistics object.
*/
public String getName() {
return name;
}
/**
* @return the associated file system scheme if this is scheme specific,
* else return null.
*/
public String getScheme() {
return null;
}
/**
* Get an iterator over all the currently tracked long statistics.
*
* The values returned will depend on the type of FileSystem or FileContext
* object. The values do not necessarily reflect a snapshot in time.
*/
public abstract Iterator getLongStatistics();
/**
* Get the value of a statistic.
*
* @return null if the statistic is not being tracked or is not a
* long statistic. The value of the statistic, otherwise.
*/
public abstract Long getLong(String key);
/**
* Return true if a statistic is being tracked.
*
* @return True only if the statistic is being tracked.
*/
public abstract boolean isTracked(String key);
/**
* Reset all the statistic data.
*/
public abstract void reset();
}