org.apache.hadoop.fs.s3a.statistics.S3AInputStreamStatistics 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.s3a.statistics;
import org.apache.hadoop.fs.statistics.DurationTracker;
/**
* Statistics updated by a
* {@link org.apache.hadoop.fs.s3a.S3AInputStream} during its use.
* It also contains getters for tests.
*/
public interface S3AInputStreamStatistics extends AutoCloseable,
S3AStatisticInterface {
/**
* Seek backwards, incrementing the seek and backward seek counters.
* @param negativeOffset how far was the seek?
* This is expected to be negative.
*/
void seekBackwards(long negativeOffset);
/**
* Record a forward seek, adding a seek operation, a forward
* seek operation, and any bytes skipped.
* @param skipped bytes moved forward in stream
* @param bytesReadInSeek number of bytes skipped by reading from the stream.
* If the seek was implemented by a close + reopen, set this to zero.
*/
void seekForwards(long skipped, long bytesReadInSeek);
/**
* The inner stream was opened.
* The return value is used in the input stream to decide whether it is
* the initial vs later count.
* @return the previous count or zero if this is the first opening.
*/
long streamOpened();
/**
* The inner stream was closed.
* @param abortedConnection flag to indicate the stream was aborted,
* rather than closed cleanly
* @param remainingInCurrentRequest the number of bytes remaining in
* the current request.
*/
void streamClose(boolean abortedConnection,
long remainingInCurrentRequest);
/**
* An ignored stream read exception was received.
*/
void readException();
/**
* Increment the bytes read counter by the number of bytes;
* no-op if the argument is negative.
* @param bytes number of bytes read
*/
void bytesRead(long bytes);
/**
* A {@code read(byte[] buf, int off, int len)} operation has started.
* @param pos starting position of the read
* @param len length of bytes to read
*/
void readOperationStarted(long pos, long len);
/**
* A {@code PositionedRead.read(position, buffer, offset, length)}
* operation has just started.
* @param pos starting position of the read
* @param len length of bytes to read
*/
void readFullyOperationStarted(long pos, long len);
/**
* A read operation has completed.
* @param requested number of requested bytes
* @param actual the actual number of bytes
*/
void readOperationCompleted(int requested, int actual);
@Override
void close();
/**
* The input policy has been switched.
* @param updatedPolicy enum value of new policy.
*/
void inputPolicySet(int updatedPolicy);
/**
* Get a reference to the change tracker statistics for this
* stream.
* @return a reference to the change tracker statistics
*/
ChangeTrackerStatistics getChangeTrackerStatistics();
/**
* A stream {@code unbuffer()} call has been made.
*/
void unbuffered();
long getCloseOperations();
long getClosed();
long getAborted();
long getForwardSeekOperations();
long getBackwardSeekOperations();
/**
* The bytes read in read() operations.
* @return the number of bytes returned to the caller.
*/
long getBytesRead();
/**
* The total number of bytes read, including
* all read and discarded when closing streams
* or skipped during seek calls.
* @return the total number of bytes read from
* S3.
*/
long getTotalBytesRead();
long getBytesSkippedOnSeek();
long getBytesBackwardsOnSeek();
long getBytesReadInClose();
long getBytesDiscardedInAbort();
long getOpenOperations();
long getSeekOperations();
long getReadExceptions();
long getReadOperations();
long getReadFullyOperations();
long getReadsIncomplete();
long getPolicySetCount();
long getVersionMismatches();
long getInputPolicy();
/**
* Get the value of a counter.
* @param name counter name
* @return the value or null if no matching counter was found.
*/
Long lookupCounterValue(String name);
/**
* Get the value of a gauge.
* @param name gauge name
* @return the value or null if no matching gauge was found.
*/
Long lookupGaugeValue(String name);
/**
* Initiate a GET request.
* @return duration tracker;
*/
DurationTracker initiateGetRequest();
}