HADOOP-16193. Add extra S3A MPU test to see what happens if a file is created during the MPU. Contributed by Steve Loughran

hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/contract/s3a/ITestS3AContractMultipartUploader.java

@@ -17,20 +17,31 @@
  */
 package org.apache.hadoop.fs.contract.s3a;
 
+import java.io.ByteArrayInputStream;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.junit.Test;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.MultipartUploader;
+import org.apache.hadoop.fs.PartHandle;
 import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.UploadHandle;
 import org.apache.hadoop.fs.contract.AbstractFSContract;
 import org.apache.hadoop.fs.contract.AbstractContractMultipartUploaderTest;
 import org.apache.hadoop.fs.contract.ContractTestUtils;
 import org.apache.hadoop.fs.s3a.S3AFileSystem;
 import org.apache.hadoop.fs.s3a.WriteOperationHelper;
 
+import static org.apache.hadoop.fs.contract.ContractTestUtils.dataset;
 import static org.apache.hadoop.fs.s3a.S3ATestConstants.*;
 import static org.apache.hadoop.fs.s3a.S3ATestUtils.*;
 import static org.apache.hadoop.fs.s3a.scale.AbstractSTestS3AHugeFiles.DEFAULT_HUGE_PARTITION_SIZE;
+import static org.apache.hadoop.test.LambdaTestUtils.eventually;
 
 /**
  * Test MultipartUploader with S3A.
@@ -159,4 +170,47 @@ public class ITestS3AContractMultipartUploader extends
   public void testMultipartUploadReverseOrder() throws Exception {
     ContractTestUtils.skip("skipped for speed");
   }
+
+  /**
+   * This creates and then deletes a zero-byte file while an upload
+   * is in progress, and verifies that the uploaded file is ultimately
+   * visible.
+   */
+  @Test
+  public void testMultipartOverlapWithTransientFile() throws Throwable {
+    // until there's a way to explicitly ask for a multipart uploader from a
+    // specific FS, explicitly create one bonded to the raw FS.
+    describe("testMultipartOverlapWithTransientFile");
+    S3AFileSystem fs = getFileSystem();
+    Path path = path("testMultipartOverlapWithTransientFile");
+    fs.delete(path, true);
+    MultipartUploader mpu = mpu(1);
+    UploadHandle upload1 = mpu.initialize(path);
+    byte[] dataset = dataset(1024, '0', 10);
+    final Map<Integer, PartHandle> handles = new HashMap<>();
+    LOG.info("Uploading multipart entry");
+    PartHandle value = mpu.putPart(path, new ByteArrayInputStream(dataset), 1,
+        upload1,
+        dataset.length);
+    // upload 1K
+    handles.put(1, value);
+    // confirm the path is absent
+    ContractTestUtils.assertPathDoesNotExist(fs,
+        "path being uploaded", path);
+    // now create an empty file
+    ContractTestUtils.touch(fs, path);
+    final FileStatus touchStatus = fs.getFileStatus(path);
+    LOG.info("0-byte file has been created: {}", touchStatus);
+    fs.delete(path, false);
+    // now complete the upload
+    mpu.complete(path, handles, upload1);
+
+    // wait for the data to arrive
+    eventually(timeToBecomeConsistentMillis(), 500, () -> {
+      FileStatus mpuStatus = fs.getFileStatus(path);
+      assertTrue("File is empty in " + mpuStatus, mpuStatus.getLen() > 0);
+      return mpuStatus;
+    });
+
+  }
 }