Support to emit multiple streams for a file content each responsible …

…for processing a specific part of the file

Signed-off-by: Raghuvansh Raj <raghraaj@amazon.com>

CHANGELOG.md

@@ -96,6 +96,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Add new cluster settings to ignore weighted round-robin routing and fallback to default behaviour. ([#6834](https://github.com/opensearch-project/OpenSearch/pull/6834))
 - Add experimental support for ZSTD compression. ([#3577](https://github.com/opensearch-project/OpenSearch/pull/3577))
 - [Segment Replication] Add point in time and scroll query compatibility. ([#6644](https://github.com/opensearch-project/OpenSearch/pull/6644))
+- [Remote Store] Support to emit multiple streams for a file content each responsible for processing a specific part of the file ([#6977](https://github.com/opensearch-project/OpenSearch/pull/6977))
 
 ### Dependencies
 - Bump `org.apache.logging.log4j:log4j-core` from 2.18.0 to 2.20.0 ([#6490](https://github.com/opensearch-project/OpenSearch/pull/6490))
@@ -133,4 +134,4 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ### Security
 
 [Unreleased 3.0]: https://github.com/opensearch-project/OpenSearch/compare/2.x...HEAD
-[Unreleased 2.x]: https://github.com/opensearch-project/OpenSearch/compare/2.5...2.x
+[Unreleased 2.x]: https://github.com/opensearch-project/OpenSearch/compare/2.5...2.x

server/src/main/java/org/opensearch/common/Stream.java

@@ -0,0 +1,55 @@
+/*
+ * 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.common;
+
+import java.io.InputStream;
+
+/**
+ * Model composed of an input stream, the total content length and offset
+ */
+public class Stream {
+
+    private final InputStream inputStream;
+    private final long contentLength;
+    private final long offset;
+
+    /**
+     * Construct a new stream object
+     *
+     * @param inputStream The input stream that is to be encapsulated
+     * @param contentLength The total content length that is to be read from the stream
+     * @param offset The offset pointer that this stream reads from in the file
+     */
+    public Stream(InputStream inputStream, long contentLength, long offset) {
+        this.inputStream = inputStream;
+        this.contentLength = contentLength;
+        this.offset = offset;
+    }
+
+    /**
+     * @return The input stream this object is reading from
+     */
+    public InputStream getInputStream() {
+        return inputStream;
+    }
+
+    /**
+     * @return The total length of the content that has to be read from this stream
+     */
+    public long getContentLength() {
+        return contentLength;
+    }
+
+    /**
+     * @return The offset pointer in the file that this stream is reading from
+     */
+    public long getOffset() {
+        return offset;
+    }
+}

server/src/main/java/org/opensearch/common/StreamProvider.java

@@ -0,0 +1,47 @@
+/*
+ * 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.common;
+
+import java.io.IOException;
+
+/**
+ * StreamProvider is used to supply streams to vendor plugins using <code>StreamProvider#provideStream</code>
+ */
+public class StreamProvider {
+
+    private final TransferPartStreamSupplier streamSupplier;
+    private final long partSize;
+    private final long lastPartSize;
+    private final int numOfParts;
+
+    /**
+     * Construct a new StreamProvider object
+     *
+     * @param streamSupplier An implementation of TransferPartStreamSupplier which will be called when provideStreams is called
+     * @param partSize Size of all parts apart from the last one
+     * @param lastPartSize Size of the last part
+     * @param numOfParts Total number of parts
+     */
+    public StreamProvider(TransferPartStreamSupplier streamSupplier, long partSize, long lastPartSize, int numOfParts) {
+        this.streamSupplier = streamSupplier;
+        this.partSize = partSize;
+        this.lastPartSize = lastPartSize;
+        this.numOfParts = numOfParts;
+    }
+
+    /**
+     * @param partNumber The index of the part
+     * @return A stream reference to the part requested
+     */
+    public Stream provideStream(int partNumber) throws IOException {
+        long position = partSize * partNumber;
+        long size = (partNumber == numOfParts - 1) ? lastPartSize : partSize;
+        return streamSupplier.supply(partNumber, size, position);
+    }
+}

server/src/main/java/org/opensearch/common/TransferPartStreamSupplier.java

@@ -0,0 +1,19 @@
+/*
+ * 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.common;
+
+import java.io.IOException;
+
+/**
+ * TransferPartStreamSupplier is used to supply streams to specific parts of a file based on
+ * the partNo, size and position (the offset in the file)
+ */
+public interface TransferPartStreamSupplier {
+    Stream supply(int partNo, long size, long position) throws IOException;
+}

server/src/main/java/org/opensearch/common/blobstore/stream/StreamContext.java

@@ -0,0 +1,45 @@
+/*
+ * 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.common.blobstore.stream;
+
+import org.opensearch.common.StreamProvider;
+
+/**
+ * StreamContext encapsulates all the data required for uploading multiple streams
+ */
+public class StreamContext {
+
+    private final StreamProvider streamProvider;
+    private final int numberOfParts;
+
+    /**
+     * Construct a new StreamContext object
+     *
+     * @param streamProvider A stream provider to provide a stream for a given part number.
+     * @param numberOfParts Number of parts of the content referenced by equivalent number of streams.
+     */
+    public StreamContext(StreamProvider streamProvider, int numberOfParts) {
+        this.streamProvider = streamProvider;
+        this.numberOfParts = numberOfParts;
+    }
+
+    /**
+     * @return The stream iterable for the current upload
+     */
+    public StreamProvider getStreamProvider() {
+        return streamProvider;
+    }
+
+    /**
+     * @return The number of parts in current upload
+     */
+    public int getNumberOfParts() {
+        return numberOfParts;
+    }
+}

server/src/main/java/org/opensearch/common/blobstore/stream/package-info.java

@@ -0,0 +1,10 @@
+/*
+ * 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.
+ */
+
+/** Abstractions for stream based file transfers */
+package org.opensearch.common.blobstore.stream;

server/src/main/java/org/opensearch/common/blobstore/stream/write/StreamContextSupplier.java

@@ -0,0 +1,23 @@
+/*
+ * 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.common.blobstore.stream.write;
+
+import org.opensearch.common.blobstore.stream.StreamContext;
+
+/**
+ * Will return the <code>StreamContext</code> to the caller given the part size
+ */
+public interface StreamContextSupplier {
+
+    /**
+     * @param partSize The size of a single part to be uploaded
+     * @return The <code>StreamContext</code> based on the part size provided
+     */
+    StreamContext supplyStreamContext(long partSize);
+}

server/src/main/java/org/opensearch/common/blobstore/stream/write/WriteContext.java

@@ -0,0 +1,90 @@
+/*
+ * 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.common.blobstore.stream.write;
+
+import org.opensearch.common.blobstore.stream.StreamContext;
+import org.opensearch.common.blobstore.transfer.UploadFinalizer;
+
+/**
+ * WriteContext is used to encapsulate all data needed by <code>BlobContainer#writeStreams</code>
+ */
+public class WriteContext {
+
+    private final String fileName;
+    private final StreamContextSupplier streamContextSupplier;
+    private final long fileSize;
+    private final boolean failIfAlreadyExists;
+    private final WritePriority writePriority;
+    private final UploadFinalizer uploadFinalizer;
+
+    /**
+     * Construct a new WriteContext object
+     *
+     * @param fileName The name of the file being uploaded
+     * @param streamContextSupplier A supplier that will provide StreamContext to the plugin
+     * @param fileSize The total size of the file being uploaded
+     * @param failIfAlreadyExists A boolean to fail the upload is the file exists
+     * @param writePriority The <code>WritePriority</code> of this upload
+     */
+    public WriteContext(
+        String fileName,
+        StreamContextSupplier streamContextSupplier,
+        long fileSize,
+        boolean failIfAlreadyExists,
+        WritePriority writePriority,
+        UploadFinalizer uploadFinalizer
+    ) {
+        this.fileName = fileName;
+        this.streamContextSupplier = streamContextSupplier;
+        this.fileSize = fileSize;
+        this.failIfAlreadyExists = failIfAlreadyExists;
+        this.writePriority = writePriority;
+        this.uploadFinalizer = uploadFinalizer;
+    }
+
+    /**
+     * @return The file name
+     */
+    public String getFileName() {
+        return fileName;
+    }
+
+    /**
+     * @return The boolean representing whether to fail the file upload if it exists
+     */
+    public boolean isFailIfAlreadyExists() {
+        return failIfAlreadyExists;
+    }
+
+    /**
+     * @param partSize The size of a single part to be uploaded
+     * @return The stream context which will be used by the plugin to initialize streams from the file
+     */
+    public StreamContext getStreamContext(long partSize) {
+        return streamContextSupplier.supplyStreamContext(partSize);
+    }
+
+    /**
+     * @return The total size of the file
+     */
+    public long getFileSize() {
+        return fileSize;
+    }
+
+    /**
+     * @return The <code>WritePriority</code> of the upload
+     */
+    public WritePriority getWritePriority() {
+        return writePriority;
+    }
+
+    public UploadFinalizer getUploadFinalizer() {
+        return uploadFinalizer;
+    }
+}

server/src/main/java/org/opensearch/common/blobstore/stream/write/WritePriority.java

@@ -0,0 +1,17 @@
+/*
+ * 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.common.blobstore.stream.write;
+
+/**
+ * WritePriority for upload
+ */
+public enum WritePriority {
+    NORMAL,
+    HIGH
+}

server/src/main/java/org/opensearch/common/blobstore/stream/write/package-info.java

@@ -0,0 +1,10 @@
+/*
+ * 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.
+ */
+
+/** Abstractions for stream based file writes */
+package org.opensearch.common.blobstore.stream.write;