Added support for file share reliable download

sdk/storage/azure-storage-blob/src/test/java/com/azure/storage/blob/APISpec.groovy

@@ -671,20 +671,6 @@ class APISpec extends StorageSpec {
         }
     }
 
-    class MockRetryRangeResponsePolicy implements HttpPipelinePolicy {
-        @Override
-        Mono<HttpResponse> process(HttpPipelineCallContext context, HttpPipelineNextPolicy next) {
-            return next.process().flatMap { HttpResponse response ->
-                if (response.getRequest().getHeaders().getValue("x-ms-range") != "bytes=2-6") {
-                    return Mono.<HttpResponse> error(new IllegalArgumentException("The range header was not set correctly on retry."))
-                } else {
-                    // ETag can be a dummy value. It's not validated, but DownloadResponse requires one
-                    return Mono.<HttpResponse> just(new MockDownloadHttpResponse(response, 206, Flux.error(new IOException())))
-                }
-            }
-        }
-    }
-
     /**
      * Injects one retry-able IOException failure per url.
      */

sdk/storage/azure-storage-blob/src/test/java/com/azure/storage/blob/BlobAPITest.groovy

@@ -50,6 +50,7 @@ import com.azure.storage.common.test.shared.extensions.LiveOnly
 import com.azure.storage.common.test.shared.extensions.PlaybackOnly
 import com.azure.storage.common.test.shared.extensions.RequiredServiceVersion
 import com.azure.storage.common.test.shared.policy.MockFailureResponsePolicy
+import com.azure.storage.common.test.shared.policy.MockRetryRangeResponsePolicy
 import reactor.core.Exceptions
 import reactor.core.publisher.Flux
 import reactor.core.publisher.Hooks
@@ -377,7 +378,7 @@ class BlobAPITest extends APISpec {
         constructed in BlobClient.download().
          */
         setup:
-        def bu2 = getBlobClient(env.primaryAccount.credential, bc.getBlobUrl(), new MockRetryRangeResponsePolicy())
+        def bu2 = getBlobClient(env.primaryAccount.credential, bc.getBlobUrl(), new MockRetryRangeResponsePolicy("bytes=2-6"))
 
         when:
         def range = new BlobRange(2, 5L)

sdk/storage/azure-storage-common/src/test-shared/java/com/azure/storage/common/test/shared/policy/MockRetryRangeResponsePolicy.java

@@ -0,0 +1,34 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package com.azure.storage.common.test.shared.policy;
+
+import com.azure.core.http.HttpPipelineCallContext;
+import com.azure.core.http.HttpPipelineNextPolicy;
+import com.azure.core.http.HttpResponse;
+import com.azure.core.http.policy.HttpPipelinePolicy;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import java.io.IOException;
+
+public class MockRetryRangeResponsePolicy implements HttpPipelinePolicy {
+
+    private final String rangeMatch;
+
+    public MockRetryRangeResponsePolicy(String rangeMatch) {
+        this.rangeMatch = rangeMatch;
+    }
+
+    @Override
+    public Mono<HttpResponse> process(HttpPipelineCallContext context, HttpPipelineNextPolicy next) {
+        return next.process().flatMap(response -> {
+            if (!response.getRequest().getHeaders().getValue("x-ms-range").equals(rangeMatch)) {
+                return Mono.error(new IllegalArgumentException("The range header was not set correctly on retry."));
+            } else {
+                // ETag can be a dummy value. It's not validated, but DownloadResponse requires one
+                return Mono.just(new MockDownloadHttpResponse(response, 206, Flux.error(new IOException())));
+            }
+        });
+    }
+}

sdk/storage/azure-storage-file-datalake/src/test/java/com/azure/storage/file/datalake/APISpec.groovy

@@ -485,20 +485,6 @@ class APISpec extends StorageSpec {
         }
     }
 
-    class MockRetryRangeResponsePolicy implements HttpPipelinePolicy {
-        @Override
-        Mono<HttpResponse> process(HttpPipelineCallContext context, HttpPipelineNextPolicy next) {
-            return next.process().flatMap { HttpResponse response ->
-                if (response.getRequest().getHeaders().getValue("x-ms-range") != "bytes=2-6") {
-                    return Mono.<HttpResponse> error(new IllegalArgumentException("The range header was not set correctly on retry."))
-                } else {
-                    // ETag can be a dummy value. It's not validated, but DownloadResponse requires one
-                    return Mono.<HttpResponse> just(new MockDownloadHttpResponse(response, 206, Flux.error(new IOException())))
-                }
-            }
-        }
-    }
-
     def getMockRequest() {
         HttpHeaders headers = new HttpHeaders()
         headers.put(Constants.HeaderConstants.CONTENT_ENCODING, "en-US")

sdk/storage/azure-storage-file-datalake/src/test/java/com/azure/storage/file/datalake/FileAPITest.groovy

@@ -15,6 +15,7 @@ import com.azure.storage.blob.models.BlockListType
 import com.azure.storage.common.test.shared.extensions.LiveOnly
 import com.azure.storage.common.test.shared.extensions.RequiredServiceVersion
 import com.azure.storage.common.test.shared.policy.MockFailureResponsePolicy
+import com.azure.storage.common.test.shared.policy.MockRetryRangeResponsePolicy
 import com.azure.storage.file.datalake.models.DownloadRetryOptions
 import com.azure.storage.file.datalake.models.AccessTier
 import com.azure.storage.file.datalake.models.DataLakeRequestConditions
@@ -979,7 +980,7 @@ class FileAPITest extends APISpec {
         constructed in BlobClient.download().
          */
         setup:
-        def fileClient = getFileClient(env.dataLakeAccount.credential, fc.getPathUrl(), new MockRetryRangeResponsePolicy())
+        def fileClient = getFileClient(env.dataLakeAccount.credential, fc.getPathUrl(), new MockRetryRangeResponsePolicy("bytes=2-6"))
 
         fc.append(new ByteArrayInputStream(data.defaultBytes), 0, data.defaultDataSize)
         fc.flush(data.defaultDataSize)

sdk/storage/azure-storage-file-share/CHANGELOG.md

@@ -1,6 +1,7 @@
 # Release History
 
 ## 12.11.0-beta.1 (Unreleased)
+- Added support to reliably download a file. 
 - Added support for the 2020-10-02 service version.
 
 ## 12.10.0 (2021-06-09)

sdk/storage/azure-storage-file-share/src/main/java/com/azure/storage/file/share/ShareFileAsyncClient.java

@@ -14,6 +14,7 @@
 import com.azure.core.http.rest.PagedResponseBase;
 import com.azure.core.http.rest.Response;
 import com.azure.core.http.rest.SimpleResponse;
+import com.azure.core.http.rest.StreamResponse;
 import com.azure.core.util.Context;
 import com.azure.core.util.CoreUtils;
 import com.azure.core.util.FluxUtil;
@@ -48,6 +49,7 @@
 import com.azure.storage.file.share.implementation.util.ShareSasImplUtil;
 import com.azure.storage.file.share.models.CloseHandlesInfo;
 import com.azure.storage.file.share.models.CopyStatusType;
+import com.azure.storage.file.share.models.DownloadRetryOptions;
 import com.azure.storage.file.share.models.HandleItem;
 import com.azure.storage.file.share.models.LeaseDurationType;
 import com.azure.storage.file.share.models.LeaseStateType;
@@ -58,6 +60,7 @@
 import com.azure.storage.file.share.models.ShareErrorCode;
 import com.azure.storage.file.share.models.ShareFileCopyInfo;
 import com.azure.storage.file.share.models.ShareFileDownloadAsyncResponse;
+import com.azure.storage.file.share.models.ShareFileDownloadHeaders;
 import com.azure.storage.file.share.models.ShareFileHttpHeaders;
 import com.azure.storage.file.share.models.ShareFileInfo;
 import com.azure.storage.file.share.models.ShareFileMetadataInfo;
@@ -70,6 +73,7 @@
 import com.azure.storage.file.share.models.ShareFileUploadRangeFromUrlInfo;
 import com.azure.storage.file.share.models.ShareRequestConditions;
 import com.azure.storage.file.share.models.ShareStorageException;
+import com.azure.storage.file.share.options.ShareFileDownloadOptions;
 import com.azure.storage.file.share.options.ShareFileListRangesDiffOptions;
 import com.azure.storage.file.share.sas.ShareServiceSasSignatureValues;
 import reactor.core.Exceptions;
@@ -93,6 +97,7 @@
 import java.time.OffsetDateTime;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.ConcurrentModificationException;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
@@ -134,6 +139,7 @@ public class ShareFileAsyncClient {
     static final long FILE_DEFAULT_BLOCK_SIZE = 4 * 1024 * 1024L;
     static final long FILE_MAX_PUT_RANGE_SIZE = 4 * Constants.MB;
     private static final long DOWNLOAD_UPLOAD_CHUNK_TIMEOUT = 300;
+    private static final Duration TIMEOUT_VALUE = Duration.ofSeconds(60);
 
     private final AzureFileStorageImpl azureFileStorageClient;
     private final String shareName;
@@ -734,7 +740,8 @@ private Mono<Response<ShareFileProperties>> downloadResponseInChunk(Response<Sha
                 }
                 return chunks;
             }).flatMapMany(Flux::fromIterable).flatMap(chunk ->
-                downloadWithResponse(chunk, false, requestConditions, context)
+                downloadWithResponse(new ShareFileDownloadOptions().setRange(chunk).setRangeContentMd5(false)
+                    .setRequestConditions(requestConditions), context)
                 .map(ShareFileDownloadAsyncResponse::getValue)
                 .subscribeOn(Schedulers.elastic())
                 .flatMap(fbb -> FluxUtil
@@ -778,8 +785,7 @@ private void channelCleanUp(AsynchronousFileChannel channel) {
      */
     public Flux<ByteBuffer> download() {
         try {
-            return downloadWithResponse(null, null).flatMapMany(
-                ShareFileDownloadAsyncResponse::getValue);
+            return downloadWithResponse(null).flatMapMany(ShareFileDownloadAsyncResponse::getValue);
         } catch (RuntimeException ex) {
             return fluxError(logger, ex);
         }
@@ -826,25 +832,111 @@ public Mono<ShareFileDownloadAsyncResponse> downloadWithResponse(ShareFileRange
      */
     public Mono<ShareFileDownloadAsyncResponse> downloadWithResponse(ShareFileRange range, Boolean rangeGetContentMD5,
         ShareRequestConditions requestConditions) {
+        return downloadWithResponse(new ShareFileDownloadOptions().setRange(range)
+            .setRangeContentMd5(rangeGetContentMD5).setRequestConditions(requestConditions));
+    }
+
+    /**
+     * Downloads a file from the system, including its metadata and properties
+     *
+     * <p><strong>Code Samples</strong></p>
+     *
+     * <p>Download the file from 1024 to 2048 bytes with its metadata and properties and without the contentMD5. </p>
+     *
+     * {@codesnippet com.azure.storage.file.share.ShareFileAsyncClient.downloadWithResponse#ShareFileDownloadOptions}
+     *
+     * <p>For more information, see the
+     * <a href="https://docs.microsoft.com/rest/api/storageservices/get-file">Azure Docs</a>.</p>
+     *
+     * @param options {@link ShareFileDownloadOptions}
+     * true, as long as the range is less than or equal to 4 MB in size.
+     * @return A reactive response containing response data and the file data.
+     */
+    public Mono<ShareFileDownloadAsyncResponse> downloadWithResponse(ShareFileDownloadOptions options) {
         try {
-            return withContext(context -> downloadWithResponse(range, rangeGetContentMD5,
-                requestConditions, context));
+            return withContext(context -> downloadWithResponse(options, context));
         } catch (RuntimeException ex) {
             return monoError(logger, ex);
         }
     }
 
-    Mono<ShareFileDownloadAsyncResponse> downloadWithResponse(ShareFileRange range, Boolean rangeGetContentMD5,
+    Mono<ShareFileDownloadAsyncResponse> downloadWithResponse(ShareFileDownloadOptions options, Context context) {
+        options = options == null ? new ShareFileDownloadOptions() : options;
+        ShareFileRange range = options.getRange() == null ? new ShareFileRange(0) : options.getRange();
+        ShareRequestConditions requestConditions = options.getRequestConditions() == null
+            ? new ShareRequestConditions() : options.getRequestConditions();
+        DownloadRetryOptions retryOptions = options.getRetryOptions() == null ? new DownloadRetryOptions()
+            : options.getRetryOptions();
+        Boolean getRangeContentMd5 = options.getRangeContentMd5();
+
+        return downloadRange(range, getRangeContentMd5, requestConditions, context)
+            .map(response -> {
+                String eTag = ModelHelper.getETag(response.getHeaders());
+                ShareFileDownloadHeaders headers = ModelHelper.transformFileDownloadHeaders(response.getHeaders());
+
+                long finalEnd;
+                if (range.getEnd() == null) {
+                    finalEnd = headers.getContentRange() == null ? headers.getContentLength()
+                        : Long.parseLong(headers.getContentRange().split("/")[1]);
+                } else {
+                    finalEnd = range.getEnd();
+                }
+
+                Flux<ByteBuffer> bufferFlux  = FluxUtil.createRetriableDownloadFlux(
+                    () -> response.getValue().timeout(TIMEOUT_VALUE),
+                    (throwable, offset) -> {
+                        if (!(throwable instanceof IOException || throwable instanceof TimeoutException)) {
+                            return Flux.error(throwable);
+                        }
+
+                        long newCount = finalEnd - (offset - range.getStart());
+
+                        /*
+                         It is possible that the network stream will throw an error after emitting all data but before
+                         completing. Issuing a retry at this stage would leave the download in a bad state with incorrect count
+                         and offset values. Because we have read the intended amount of data, we can ignore the error at the end
+                         of the stream.
+                         */
+                        if (newCount == 0) {
+                            logger.warning("Exception encountered in ReliableDownload after all data read from the network but "
+                                + "but before stream signaled completion. Returning success as all data was downloaded. "
+                                + "Exception message: " + throwable.getMessage());
+                            return Flux.empty();
+                        }
+
+                        try {
+                            return downloadRange(
+                                new ShareFileRange(offset, range.getEnd()), getRangeContentMd5,
+                                requestConditions, context).flatMapMany(r -> {
+                                    String receivedETag = ModelHelper.getETag(r.getHeaders());
+                                    if ((eTag == null && receivedETag == null)
+                                        || (eTag != null && eTag.equals(receivedETag))) {
+                                        return r.getValue().timeout(TIMEOUT_VALUE);
+                                    } else {
+                                        return Flux.<ByteBuffer>error(
+                                            new ConcurrentModificationException(String.format("File has been modified "
+                                                + "concurrently. Expected eTag: %s, Received eTag: %s", eTag,
+                                                receivedETag)));
+                                    }
+                                });
+                        } catch (Exception e) {
+                            return Flux.error(e);
+                        }
+                    },
+                    retryOptions.getMaxRetryRequests(),
+                    range.getStart()
+                ).switchIfEmpty(Flux.just(ByteBuffer.wrap(new byte[0])));
+
+                return new ShareFileDownloadAsyncResponse(response.getRequest(), response.getStatusCode(),
+                    response.getHeaders(), bufferFlux, headers);
+            });
+    }
+
+    private Mono<StreamResponse> downloadRange(ShareFileRange range, Boolean rangeGetContentMD5,
         ShareRequestConditions requestConditions, Context context) {
-        requestConditions = requestConditions == null ? new ShareRequestConditions() : requestConditions;
         String rangeString = range == null ? null : range.toString();
-
-        return azureFileStorageClient.getFiles()
-            .downloadWithResponseAsync(shareName, filePath, null, rangeString, rangeGetContentMD5,
-                requestConditions.getLeaseId(), context)
-            .map(response -> new ShareFileDownloadAsyncResponse(response.getRequest(), response.getStatusCode(),
-                response.getHeaders(), response.getValue(),
-                ModelHelper.transformFileDownloadHeaders(response.getHeaders())));
+        return azureFileStorageClient.getFiles().downloadWithResponseAsync(shareName, filePath, null,
+            rangeString, rangeGetContentMD5, requestConditions.getLeaseId(),  context);
     }
 
     /**

sdk/storage/azure-storage-file-share/src/main/java/com/azure/storage/file/share/ShareFileClient.java

@@ -33,6 +33,7 @@
 import com.azure.storage.file.share.models.ShareFileUploadRangeOptions;
 import com.azure.storage.file.share.models.ShareRequestConditions;
 import com.azure.storage.file.share.models.ShareStorageException;
+import com.azure.storage.file.share.options.ShareFileDownloadOptions;
 import com.azure.storage.file.share.options.ShareFileListRangesDiffOptions;
 import com.azure.storage.file.share.sas.ShareServiceSasSignatureValues;
 import reactor.core.Exceptions;
@@ -561,10 +562,36 @@ public ShareFileDownloadResponse downloadWithResponse(OutputStream stream, Share
      */
     public ShareFileDownloadResponse downloadWithResponse(OutputStream stream, ShareFileRange range,
         Boolean rangeGetContentMD5, ShareRequestConditions requestConditions, Duration timeout, Context context) {
+        return downloadWithResponse(stream, new ShareFileDownloadOptions().setRange(range)
+            .setRangeContentMd5(rangeGetContentMD5).setRequestConditions(requestConditions), timeout, context);
+    }
+
+    /**
+     * Downloads a file from the system, including its metadata and properties
+     *
+     * <p><strong>Code Samples</strong></p>
+     *
+     * <p>Download the file from 1024 to 2048 bytes with its metadata and properties and without the contentMD5. </p>
+     *
+     * {@codesnippet com.azure.storage.file.share.ShareFileClient.downloadWithResponse#OutputStream-ShareFileDownloadOptions-Duration-Context}
+     *
+     * <p>For more information, see the
+     * <a href="https://docs.microsoft.com/rest/api/storageservices/get-file">Azure Docs</a>.</p>
+     *
+     * @param stream A non-null {@link OutputStream} where the downloaded data will be written.
+     * @param options {@link ShareFileDownloadOptions}
+     * @param timeout An optional timeout applied to the operation. If a response is not returned before the timeout
+     * concludes a {@link RuntimeException} will be thrown.
+     * @param context Additional context that is passed through the Http pipeline during the service call.
+     * @return A response containing the headers and response status code
+     * @throws NullPointerException If {@code stream} is {@code null}.
+     * @throws RuntimeException if the operation doesn't complete before the timeout concludes.
+     */
+    public ShareFileDownloadResponse downloadWithResponse(OutputStream stream, ShareFileDownloadOptions options,
+        Duration timeout, Context context) {
         Objects.requireNonNull(stream, "'stream' cannot be null.");
 
-        Mono<ShareFileDownloadResponse> download = shareFileAsyncClient.downloadWithResponse(range, rangeGetContentMD5,
-            requestConditions, context)
+        Mono<ShareFileDownloadResponse> download = shareFileAsyncClient.downloadWithResponse(options, context)
             .flatMap(response -> response.getValue().reduce(stream, (outputStream, buffer) -> {
                 try {
                     outputStream.write(FluxUtil.byteBufferToArray(buffer));

sdk/storage/azure-storage-file-share/src/main/java/com/azure/storage/file/share/implementation/util/ModelHelper.java

@@ -191,6 +191,13 @@ public static ShareFileDownloadHeaders transformFileDownloadHeaders(HttpHeaders
         }
     }
 
+    public static String getETag(HttpHeaders headers) {
+        if (headers == null) {
+            return null;
+        }
+        return headers.getValue("ETag");
+    }
+
     public static ShareFileItemProperties transformFileProperty(FileProperty property) {
         if (property == null) {
             return null;