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* 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.io.wrappedio;
import java.io.Serializable;
import java.io.UncheckedIOException;
import java.util.HashMap;
import java.util.Map;
import javax.annotation.Nullable;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.statistics.IOStatistics;
import org.apache.hadoop.fs.statistics.IOStatisticsContext;
import org.apache.hadoop.fs.statistics.IOStatisticsSnapshot;
import org.apache.hadoop.fs.statistics.IOStatisticsSource;
import org.apache.hadoop.util.functional.FunctionRaisingIOE;
import org.apache.hadoop.util.functional.Tuples;
import static org.apache.hadoop.fs.statistics.IOStatisticsContext.getCurrentIOStatisticsContext;
import static org.apache.hadoop.fs.statistics.IOStatisticsContext.setThreadIOStatisticsContext;
import static org.apache.hadoop.fs.statistics.IOStatisticsLogging.ioStatisticsToPrettyString;
import static org.apache.hadoop.fs.statistics.IOStatisticsSupport.retrieveIOStatistics;
import static org.apache.hadoop.util.Preconditions.checkArgument;
import static org.apache.hadoop.util.functional.FunctionalIO.uncheckIOExceptions;
/**
* Reflection-friendly access to IOStatistics APIs.
* All {@code Serializable} arguments/return values are actually
* {@code IOStatisticsSource} instances; passing in the wrong value
* will raise IllegalArgumentExceptions.
*/
@InterfaceAudience.Public
@InterfaceStability.Unstable
public final class WrappedStatistics {
private WrappedStatistics() {
}
/**
* Probe for an object being an instance of {@code IOStatisticsSource}.
* @param object object to probe
* @return true if the object is the right type.
*/
public static boolean isIOStatisticsSource(Object object) {
return object instanceof IOStatisticsSource;
}
/**
* Probe for an object being an instance of {@code IOStatistics}.
* @param object object to probe
* @return true if the object is the right type.
*/
public static boolean isIOStatistics(Object object) {
return object instanceof IOStatistics;
}
/**
* Probe for an object being an instance of {@code IOStatisticsSnapshot}.
* @param object object to probe
* @return true if the object is the right type.
*/
public static boolean isIOStatisticsSnapshot(Serializable object) {
return object instanceof IOStatisticsSnapshot;
}
/**
* Aggregate an existing {@link IOStatisticsSnapshot} with
* the supplied statistics.
* @param snapshot snapshot to update
* @param statistics IOStatistics to add
* @return true if the snapshot was updated.
* @throws IllegalArgumentException if the {@code statistics} argument is not
* null but not an instance of IOStatistics, or if {@code snapshot} is invalid.
*/
public static boolean iostatisticsSnapshot_aggregate(
Serializable snapshot, @Nullable Object statistics) {
requireIOStatisticsSnapshot(snapshot);
if (statistics == null) {
return false;
}
checkArgument(statistics instanceof IOStatistics,
"Not an IOStatistics instance: %s", statistics);
final IOStatistics sourceStats = (IOStatistics) statistics;
return applyToIOStatisticsSnapshot(snapshot, s ->
s.aggregate(sourceStats));
}
/**
* Create a new {@link IOStatisticsSnapshot} instance.
* @return an empty IOStatisticsSnapshot.
*/
public static Serializable iostatisticsSnapshot_create() {
return iostatisticsSnapshot_create(null);
}
/**
* Create a new {@link IOStatisticsSnapshot} instance.
* @param source optional source statistics
* @return an IOStatisticsSnapshot.
* @throws ClassCastException if the {@code source} is not null and not an IOStatistics instance
*/
public static Serializable iostatisticsSnapshot_create(@Nullable Object source) {
return new IOStatisticsSnapshot((IOStatistics) source);
}
/**
* Load IOStatisticsSnapshot from a Hadoop filesystem.
* @param fs filesystem
* @param path path
* @return the loaded snapshot
* @throws UncheckedIOException Any IO exception.
*/
public static Serializable iostatisticsSnapshot_load(
FileSystem fs,
Path path) {
return uncheckIOExceptions(() ->
IOStatisticsSnapshot.serializer().load(fs, path));
}
/**
* Extract the IOStatistics from an object in a serializable form.
* @param source source object, may be null/not a statistics source/instance
* @return {@link IOStatisticsSnapshot} or null if the object is null/doesn't have statistics
*/
public static Serializable iostatisticsSnapshot_retrieve(@Nullable Object source) {
IOStatistics stats = retrieveIOStatistics(source);
if (stats == null) {
return null;
}
return iostatisticsSnapshot_create(stats);
}
/**
* Save IOStatisticsSnapshot to a Hadoop filesystem as a JSON file.
* @param snapshot statistics
* @param fs filesystem
* @param path path
* @param overwrite should any existing file be overwritten?
* @throws UncheckedIOException Any IO exception.
*/
public static void iostatisticsSnapshot_save(
@Nullable Serializable snapshot,
FileSystem fs,
Path path,
boolean overwrite) {
applyToIOStatisticsSnapshot(snapshot, s -> {
IOStatisticsSnapshot.serializer().save(fs, path, s, overwrite);
return null;
});
}
/**
* Save IOStatisticsSnapshot to a JSON string.
* @param snapshot statistics; may be null or of an incompatible type
* @return JSON string value
* @throws UncheckedIOException Any IO/jackson exception.
* @throws IllegalArgumentException if the supplied class is not a snapshot
*/
public static String iostatisticsSnapshot_toJsonString(@Nullable Serializable snapshot) {
return applyToIOStatisticsSnapshot(snapshot,
IOStatisticsSnapshot.serializer()::toJson);
}
/**
* Load IOStatisticsSnapshot from a JSON string.
* @param json JSON string value.
* @return deserialized snapshot.
* @throws UncheckedIOException Any IO/jackson exception.
*/
public static Serializable iostatisticsSnapshot_fromJsonString(
final String json) {
return uncheckIOExceptions(() ->
IOStatisticsSnapshot.serializer().fromJson(json));
}
/**
* Get the counters of an IOStatisticsSnapshot.
* @param source source of statistics.
* @return the map of counters.
*/
public static Map iostatistics_counters(
Serializable source) {
return applyToIOStatisticsSnapshot(source, IOStatisticsSnapshot::counters);
}
/**
* Get the gauges of an IOStatisticsSnapshot.
* @param source source of statistics.
* @return the map of gauges.
*/
public static Map iostatistics_gauges(
Serializable source) {
return applyToIOStatisticsSnapshot(source, IOStatisticsSnapshot::gauges);
}
/**
* Get the minimums of an IOStatisticsSnapshot.
* @param source source of statistics.
* @return the map of minimums.
*/
public static Map iostatistics_minimums(
Serializable source) {
return applyToIOStatisticsSnapshot(source, IOStatisticsSnapshot::minimums);
}
/**
* Get the maximums of an IOStatisticsSnapshot.
* @param source source of statistics.
* @return the map of maximums.
*/
public static Map iostatistics_maximums(
Serializable source) {
return applyToIOStatisticsSnapshot(source, IOStatisticsSnapshot::maximums);
}
/**
* Get the means of an IOStatisticsSnapshot.
* Each value in the map is the (sample, sum) tuple of the values;
* the mean is then calculated by dividing sum/sample wherever sample count is non-zero.
* @param source source of statistics.
* @return a map of mean key to (sample, sum) tuples.
*/
public static Map> iostatistics_means(
Serializable source) {
return applyToIOStatisticsSnapshot(source, stats -> {
Map> map = new HashMap<>();
stats.meanStatistics().forEach((k, v) ->
map.put(k, Tuples.pair(v.getSamples(), v.getSum())));
return map;
});
}
/**
* Get the context's {@link IOStatisticsContext} which
* implements {@link IOStatisticsSource}.
* This is either a thread-local value or a global empty context.
* @return instance of {@link IOStatisticsContext}.
*/
public static Object iostatisticsContext_getCurrent() {
return getCurrentIOStatisticsContext();
}
/**
* Set the IOStatisticsContext for the current thread.
* @param statisticsContext IOStatistics context instance for the
* current thread. If null, the context is reset.
*/
public static void iostatisticsContext_setThreadIOStatisticsContext(
@Nullable Object statisticsContext) {
setThreadIOStatisticsContext((IOStatisticsContext) statisticsContext);
}
/**
* Static probe to check if the thread-level IO statistics enabled.
* @return true if the thread-level IO statistics are enabled.
*/
public static boolean iostatisticsContext_enabled() {
return IOStatisticsContext.enabled();
}
/**
* Reset the context's IOStatistics.
* {@link IOStatisticsContext#reset()}
*/
public static void iostatisticsContext_reset() {
getCurrentIOStatisticsContext().reset();
}
/**
* Take a snapshot of the context IOStatistics.
* {@link IOStatisticsContext#snapshot()}
* @return an instance of {@link IOStatisticsSnapshot}.
*/
public static Serializable iostatisticsContext_snapshot() {
return getCurrentIOStatisticsContext().snapshot();
}
/**
* Aggregate into the IOStatistics context the statistics passed in via
* IOStatistics/source parameter.
*
* Returns false if the source is null or does not contain any statistics.
* @param source implementation of {@link IOStatisticsSource} or {@link IOStatistics}
* @return true if the the source object was aggregated.
*/
public static boolean iostatisticsContext_aggregate(Object source) {
IOStatistics stats = retrieveIOStatistics(source);
if (stats != null) {
getCurrentIOStatisticsContext().getAggregator().aggregate(stats);
return true;
} else {
return false;
}
}
/**
* Convert IOStatistics to a string form, with all the metrics sorted
* and empty value stripped.
* @param statistics A statistics instance; may be null
* @return string value or the empty string if null
*/
public static String iostatistics_toPrettyString(@Nullable Object statistics) {
return statistics == null
? ""
: ioStatisticsToPrettyString((IOStatistics) statistics);
}
/**
* Apply a function to an object which may be an IOStatisticsSnapshot.
* @param return type
* @param source statistics snapshot
* @param fun function to invoke if {@code source} is valid.
* @return the applied value
* @throws UncheckedIOException Any IO exception.
* @throws IllegalArgumentException if the supplied class is not a snapshot
*/
public static T applyToIOStatisticsSnapshot(
Serializable source,
FunctionRaisingIOE fun) {
return fun.unchecked(requireIOStatisticsSnapshot(source));
}
/**
* Require the parameter to be an instance of {@link IOStatisticsSnapshot}.
* @param snapshot object to validate
* @return cast value
* @throws IllegalArgumentException if the supplied class is not a snapshot
*/
private static IOStatisticsSnapshot requireIOStatisticsSnapshot(final Serializable snapshot) {
checkArgument(snapshot instanceof IOStatisticsSnapshot,
"Not an IOStatisticsSnapshot %s", snapshot);
return (IOStatisticsSnapshot) snapshot;
}
}
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