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/*
* SPDX-License-Identifier: Apache-2.0
*
* The OpenSearch Contributors require contributions made to
* this file be licensed under the Apache-2.0 license or a
* compatible open source license.
*/
package org.opensearch.index.store;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.message.ParameterizedMessage;
import org.apache.lucene.index.CorruptIndexException;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.IOContext;
import org.apache.lucene.store.IndexInput;
import org.apache.lucene.store.IndexOutput;
import org.apache.lucene.store.Lock;
import org.opensearch.ExceptionsHelper;
import org.opensearch.action.LatchedActionListener;
import org.opensearch.common.blobstore.AsyncMultiStreamBlobContainer;
import org.opensearch.common.blobstore.BlobContainer;
import org.opensearch.common.blobstore.BlobMetadata;
import org.opensearch.common.blobstore.exception.CorruptFileException;
import org.opensearch.common.blobstore.stream.write.WriteContext;
import org.opensearch.common.blobstore.stream.write.WritePriority;
import org.opensearch.common.blobstore.transfer.RemoteTransferContainer;
import org.opensearch.common.blobstore.transfer.stream.OffsetRangeIndexInputStream;
import org.opensearch.common.blobstore.transfer.stream.OffsetRangeInputStream;
import org.opensearch.core.action.ActionListener;
import org.opensearch.core.common.unit.ByteSizeUnit;
import org.opensearch.index.store.exception.ChecksumCombinationException;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.NoSuchFileException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.atomic.AtomicReference;
import java.util.function.UnaryOperator;
import java.util.stream.Collectors;
import static org.opensearch.common.blobstore.transfer.RemoteTransferContainer.checksumOfChecksum;
/**
* A {@code RemoteDirectory} provides an abstraction layer for storing a list of files to a remote store.
* A remoteDirectory contains only files (no sub-folder hierarchy). This class does not support all the methods in
* the Directory interface. Currently, it contains implementation of methods which are used to copy files to/from
* the remote store. Implementation of remaining methods will be added as remote store is integrated with
* replication, peer recovery etc.
*
* @opensearch.internal
*/
public class RemoteDirectory extends Directory {
protected final BlobContainer blobContainer;
private static final Logger logger = LogManager.getLogger(RemoteDirectory.class);
private final UnaryOperator uploadRateLimiter;
private final UnaryOperator downloadRateLimiter;
/**
* Number of bytes in the segment file to store checksum
*/
private static final int SEGMENT_CHECKSUM_BYTES = 8;
public BlobContainer getBlobContainer() {
return blobContainer;
}
public RemoteDirectory(BlobContainer blobContainer) {
this(blobContainer, UnaryOperator.identity(), UnaryOperator.identity());
}
public RemoteDirectory(
BlobContainer blobContainer,
UnaryOperator uploadRateLimiter,
UnaryOperator downloadRateLimiter
) {
this.blobContainer = blobContainer;
this.uploadRateLimiter = uploadRateLimiter;
this.downloadRateLimiter = downloadRateLimiter;
}
/**
* Returns names of all files stored in this directory. The output must be in sorted (UTF-16,
* java's {@link String#compareTo}) order.
*/
@Override
public String[] listAll() throws IOException {
return blobContainer.listBlobs().keySet().stream().sorted().toArray(String[]::new);
}
/**
* Returns names of files with given prefix in this directory.
* @param filenamePrefix The prefix to match against file names in the directory
* @return A list of the matching filenames in the directory
* @throws IOException if there were any failures in reading from the blob container
*/
public Collection listFilesByPrefix(String filenamePrefix) throws IOException {
return blobContainer.listBlobsByPrefix(filenamePrefix).keySet();
}
public List listFilesByPrefixInLexicographicOrder(String filenamePrefix, int limit) throws IOException {
List sortedBlobList = new ArrayList<>();
AtomicReference exception = new AtomicReference<>();
final CountDownLatch latch = new CountDownLatch(1);
LatchedActionListener> actionListener = new LatchedActionListener<>(new ActionListener<>() {
@Override
public void onResponse(List blobMetadata) {
sortedBlobList.addAll(blobMetadata.stream().map(BlobMetadata::name).collect(Collectors.toList()));
}
@Override
public void onFailure(Exception e) {
exception.set(e);
}
}, latch);
try {
blobContainer.listBlobsByPrefixInSortedOrder(
filenamePrefix,
limit,
BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC,
actionListener
);
latch.await();
} catch (InterruptedException e) {
throw new IOException("Exception in listFilesByPrefixInLexicographicOrder with prefix: " + filenamePrefix, e);
}
if (exception.get() != null) {
throw new IOException(exception.get());
} else {
return sortedBlobList;
}
}
/**
* Returns stream emitted from by blob object. Should be used with a closeable block.
*
* @param fileName Name of file
* @return Stream from the blob object
* @throws IOException if fetch of stream fails with IO error
*/
public InputStream getBlobStream(String fileName) throws IOException {
return blobContainer.readBlob(fileName);
}
/**
* Removes an existing file in the directory.
*
* This method will not throw an exception when the file doesn't exist and simply ignores this case.
* This is a deviation from the {@code Directory} interface where it is expected to throw either
* {@link NoSuchFileException} or {@link FileNotFoundException} if {@code name} points to a non-existing file.
*
* @param name the name of an existing file.
* @throws IOException if the file exists but could not be deleted.
*/
@Override
public void deleteFile(String name) throws IOException {
// ToDo: Add a check for file existence
blobContainer.deleteBlobsIgnoringIfNotExists(Collections.singletonList(name));
}
/**
* Creates and returns a new instance of {@link RemoteIndexOutput} which will be used to copy files to the remote
* store.
*
*
In the {@link Directory} interface, it is expected to throw {@link java.nio.file.FileAlreadyExistsException}
* if the file already exists in the remote store. As this method does not open a file, it does not throw the
* exception.
*
* @param name the name of the file to copy to remote store.
*/
@Override
public IndexOutput createOutput(String name, IOContext context) {
return new RemoteIndexOutput(name, blobContainer);
}
/**
* Opens a stream for reading an existing file and returns {@link RemoteIndexInput} enclosing the stream.
*
* @param name the name of an existing file.
* @throws IOException in case of I/O error
* @throws NoSuchFileException if the file does not exist
*/
@Override
public IndexInput openInput(String name, IOContext context) throws IOException {
return openInput(name, fileLength(name), context);
}
public IndexInput openInput(String name, long fileLength, IOContext context) throws IOException {
InputStream inputStream = null;
try {
inputStream = blobContainer.readBlob(name);
return new RemoteIndexInput(name, downloadRateLimiter.apply(inputStream), fileLength);
} catch (Exception e) {
// Incase the RemoteIndexInput creation fails, close the input stream to avoid file handler leak.
if (inputStream != null) {
try {
inputStream.close();
} catch (Exception closeEx) {
e.addSuppressed(closeEx);
}
}
logger.error("Exception while reading blob for file: " + name + " for path " + blobContainer.path());
throw e;
}
}
/**
* Closes the remote directory. Currently, it is a no-op.
* If remote directory maintains a state in future, we need to clean it before closing the directory
*/
@Override
public void close() throws IOException {
// Do nothing
}
/**
* Returns the byte length of a file in the directory.
*
* @param name the name of an existing file.
* @throws IOException in case of I/O error
* @throws NoSuchFileException if the file does not exist
*/
@Override
public long fileLength(String name) throws IOException {
// ToDo: Instead of calling remote store each time, keep a cache with segment metadata
List metadata = blobContainer.listBlobsByPrefixInSortedOrder(name, 1, BlobContainer.BlobNameSortOrder.LEXICOGRAPHIC);
if (metadata.size() == 1 && metadata.get(0).name().equals(name)) {
return metadata.get(0).length();
}
throw new NoSuchFileException(name);
}
/**
* Guaranteed to throw an exception and leave the directory unmodified.
* Once soft deleting is supported segment files in the remote store, this method will provide details of
* number of files marked as deleted but not actually deleted from the remote store.
*
* @throws UnsupportedOperationException always
*/
@Override
public Set getPendingDeletions() throws IOException {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the directory unmodified.
* Temporary IndexOutput is not required while working with Remote store.
*
* @throws UnsupportedOperationException always
*/
@Override
public IndexOutput createTempOutput(String prefix, String suffix, IOContext context) {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the directory unmodified.
* Segment upload to the remote store will be permanent and does not require a separate sync API.
* This may change in the future if segment upload to remote store happens via cache and we need sync API to write
* the cache contents to the store permanently.
*
* @throws UnsupportedOperationException always
*/
@Override
public void sync(Collection names) throws IOException {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the directory unmodified.
* Once metadata to be stored with each shard is finalized, syncMetaData method will be used to sync the directory
* metadata to the remote store.
*
* @throws UnsupportedOperationException always
*/
@Override
public void syncMetaData() {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the directory unmodified.
* As this method is used by IndexWriter to publish commits, the implementation of this method is required when
* IndexWriter is backed by RemoteDirectory.
*
* @throws UnsupportedOperationException always
*/
@Override
public void rename(String source, String dest) throws IOException {
throw new UnsupportedOperationException();
}
/**
* Guaranteed to throw an exception and leave the directory unmodified.
* Once locking segment files in remote store is supported, implementation of this method is required with
* remote store specific LockFactory.
*
* @throws UnsupportedOperationException always
*/
@Override
public Lock obtainLock(String name) throws IOException {
throw new UnsupportedOperationException();
}
public void delete() throws IOException {
blobContainer.delete();
}
public boolean copyFrom(
Directory from,
String src,
String remoteFileName,
IOContext context,
Runnable postUploadRunner,
ActionListener listener,
boolean lowPriorityUpload
) {
if (blobContainer instanceof AsyncMultiStreamBlobContainer) {
try {
uploadBlob(from, src, remoteFileName, context, postUploadRunner, listener, lowPriorityUpload);
} catch (Exception e) {
listener.onFailure(e);
}
return true;
}
return false;
}
private void uploadBlob(
Directory from,
String src,
String remoteFileName,
IOContext ioContext,
Runnable postUploadRunner,
ActionListener listener,
boolean lowPriorityUpload
) throws Exception {
long expectedChecksum = calculateChecksumOfChecksum(from, src);
long contentLength;
try (IndexInput indexInput = from.openInput(src, ioContext)) {
contentLength = indexInput.length();
}
boolean remoteIntegrityEnabled = false;
if (getBlobContainer() instanceof AsyncMultiStreamBlobContainer) {
remoteIntegrityEnabled = ((AsyncMultiStreamBlobContainer) getBlobContainer()).remoteIntegrityCheckSupported();
}
lowPriorityUpload = lowPriorityUpload || contentLength > ByteSizeUnit.GB.toBytes(15);
RemoteTransferContainer remoteTransferContainer = new RemoteTransferContainer(
src,
remoteFileName,
contentLength,
true,
lowPriorityUpload ? WritePriority.LOW : WritePriority.NORMAL,
(size, position) -> uploadRateLimiter.apply(new OffsetRangeIndexInputStream(from.openInput(src, ioContext), size, position)),
expectedChecksum,
remoteIntegrityEnabled
);
ActionListener completionListener = ActionListener.wrap(resp -> {
try {
postUploadRunner.run();
listener.onResponse(null);
} catch (Exception e) {
logger.error(() -> new ParameterizedMessage("Exception in segment postUpload for file [{}]", src), e);
listener.onFailure(e);
}
}, ex -> {
logger.error(() -> new ParameterizedMessage("Failed to upload blob {}", src), ex);
IOException corruptIndexException = ExceptionsHelper.unwrapCorruption(ex);
if (corruptIndexException != null) {
listener.onFailure(corruptIndexException);
return;
}
Throwable throwable = ExceptionsHelper.unwrap(ex, CorruptFileException.class);
if (throwable != null) {
CorruptFileException corruptFileException = (CorruptFileException) throwable;
listener.onFailure(new CorruptIndexException(corruptFileException.getMessage(), corruptFileException.getFileName()));
return;
}
listener.onFailure(ex);
});
completionListener = ActionListener.runBefore(completionListener, () -> {
try {
remoteTransferContainer.close();
} catch (Exception e) {
logger.warn("Error occurred while closing streams", e);
}
});
WriteContext writeContext = remoteTransferContainer.createWriteContext();
((AsyncMultiStreamBlobContainer) blobContainer).asyncBlobUpload(writeContext, completionListener);
}
private long calculateChecksumOfChecksum(Directory directory, String file) throws IOException {
try (IndexInput indexInput = directory.openInput(file, IOContext.DEFAULT)) {
try {
return checksumOfChecksum(indexInput, SEGMENT_CHECKSUM_BYTES);
} catch (Exception e) {
throw new ChecksumCombinationException(
"Potentially corrupted file: Checksum combination failed while combining stored checksum "
+ "and calculated checksum of stored checksum in segment file: "
+ file
+ ", directory: "
+ directory,
file,
e
);
}
}
}
}