Add Part::delete method

This commit introduces the Part::delete method, that deletes its
underlying storage.

Closes gh-27612

Author: poutsma

spring-web/src/main/java/org/springframework/http/codec/multipart/Content.java

@@ -0,0 +1,129 @@
+/*
+ * Copyright 2002-2021 the original author or authors.
+ *
+ * Licensed 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
+ *
+ *      https://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.springframework.http.codec.multipart;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import reactor.core.scheduler.Scheduler;
+
+import org.springframework.core.io.buffer.DataBuffer;
+import org.springframework.core.io.buffer.DataBufferUtils;
+import org.springframework.core.io.buffer.DefaultDataBufferFactory;
+
+/**
+ * Part content abstraction used by {@link DefaultParts}.
+ *
+ * @author Arjen Poutsma
+ * @since 5.3.13
+ */
+abstract class Content {
+
+
+	protected Content() {
+	}
+
+	/**
+	 * Return the content.
+	 */
+	public abstract Flux<DataBuffer> content();
+
+	/**
+	 * Delete this content. Default implementation does nothing.
+	 */
+	public Mono<Void> delete() {
+		return Mono.empty();
+	}
+
+	/**
+	 * Returns a new {@code Content} based on the given flux of data buffers.
+	 */
+	public static Content fromFlux(Flux<DataBuffer> content) {
+		return new FluxContent(content);
+	}
+
+	/**
+	 * Return a new {@code Content} based on the given file path.
+	 */
+	public static Content fromFile(Path file, Scheduler scheduler) {
+		return new FileContent(file, scheduler);
+	}
+
+
+	/**
+	 * {@code Content} implementation based on a flux of data buffers.
+	 */
+	private static final class FluxContent extends Content {
+
+		private final Flux<DataBuffer> content;
+
+
+		public FluxContent(Flux<DataBuffer> content) {
+			this.content = content;
+		}
+
+
+		@Override
+		public Flux<DataBuffer> content() {
+			return this.content;
+		}
+	}
+
+
+	/**
+	 * {@code Content} implementation based on a file.
+	 */
+	private static final class FileContent extends Content {
+
+		private final Path file;
+
+		private final Scheduler scheduler;
+
+
+		public FileContent(Path file, Scheduler scheduler) {
+			this.file = file;
+			this.scheduler = scheduler;
+		}
+
+
+		@Override
+		public Flux<DataBuffer> content() {
+			return DataBufferUtils.readByteChannel(
+					() -> Files.newByteChannel(this.file, StandardOpenOption.READ),
+							DefaultDataBufferFactory.sharedInstance, 1024)
+					.subscribeOn(this.scheduler);
+		}
+
+		@Override
+		public Mono<Void> delete() {
+			return Mono.<Void>fromRunnable(() -> {
+						try {
+							Files.delete(this.file);
+						}
+						catch (IOException ex) {
+							throw new UncheckedIOException(ex);
+						}
+					})
+					.subscribeOn(this.scheduler);
+		}
+	}
+}

spring-web/src/main/java/org/springframework/http/codec/multipart/DefaultParts.java

@@ -57,7 +57,7 @@ public static FormFieldPart formFieldPart(HttpHeaders headers, String value) {
 	 * @param content the content of the part
 	 * @return {@link Part} or {@link FilePart}, depending on {@link HttpHeaders#getContentDisposition()}
 	 */
-	public static Part part(HttpHeaders headers, Flux<DataBuffer> content) {
+	public static Part part(HttpHeaders headers, Content content) {
 		Assert.notNull(headers, "Headers must not be null");
 		Assert.notNull(content, "Content must not be null");
 
@@ -142,16 +142,21 @@ public String toString() {
 	 */
 	private static class DefaultPart extends AbstractPart {
 
-		private final Flux<DataBuffer> content;
+		private final Content content;
 
-		public DefaultPart(HttpHeaders headers, Flux<DataBuffer> content) {
+		public DefaultPart(HttpHeaders headers, Content content) {
 			super(headers);
 			this.content = content;
 		}
 
 		@Override
 		public Flux<DataBuffer> content() {
-			return this.content;
+			return this.content.content();
+		}
+
+		@Override
+		public Mono<Void> delete() {
+			return this.content.delete();
 		}
 
 		@Override
@@ -171,9 +176,9 @@ public String toString() {
 	/**
 	 * Default implementation of {@link FilePart}.
 	 */
-	private static class DefaultFilePart extends DefaultPart implements FilePart {
+	private static final class DefaultFilePart extends DefaultPart implements FilePart {
 
-		public DefaultFilePart(HttpHeaders headers, Flux<DataBuffer> content) {
+		public DefaultFilePart(HttpHeaders headers, Content content) {
 			super(headers, content);
 		}
 

spring-web/src/main/java/org/springframework/http/codec/multipart/Part.java

@@ -17,6 +17,7 @@
 package org.springframework.http.codec.multipart;
 
 import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
 
 import org.springframework.core.io.buffer.DataBuffer;
 import org.springframework.http.HttpHeaders;
@@ -57,4 +58,13 @@ public interface Part {
 	 */
 	Flux<DataBuffer> content();
 
+	/**
+	 * Return a mono that, when subscribed to, deletes the underlying storage
+	 * for this part.
+	 * @since 5.3.13
+	 */
+	default Mono<Void> delete() {
+		return Mono.empty();
+	}
+
 }

spring-web/src/main/java/org/springframework/http/codec/multipart/PartGenerator.java

@@ -160,7 +160,7 @@ else if (!this.streaming) {
 					requestToken();
 				}
 			});
-			emitPart(DefaultParts.part(headers, streamingContent));
+			emitPart(DefaultParts.part(headers, Content.fromFlux(streamingContent)));
 		}
 	}
 
@@ -518,7 +518,7 @@ private void emitMemoryPart() {
 			}
 			this.content.clear();
 			Flux<DataBuffer> content = Flux.just(DefaultDataBufferFactory.sharedInstance.wrap(bytes));
-			emitPart(DefaultParts.part(this.headers, content));
+			emitPart(DefaultParts.part(this.headers, Content.fromFlux(content)));
 		}
 
 		@Override
@@ -674,21 +674,13 @@ public void body(DataBuffer dataBuffer) {
 		@Override
 		public void partComplete(boolean finalPart) {
 			MultipartUtils.closeChannel(this.channel);
-			Flux<DataBuffer> content = partContent();
-			emitPart(DefaultParts.part(this.headers, content));
+			emitPart(DefaultParts.part(this.headers,
+					Content.fromFile(this.file, PartGenerator.this.blockingOperationScheduler)));
 			if (finalPart) {
 				emitComplete();
 			}
 		}
 
-		private Flux<DataBuffer> partContent() {
-			return DataBufferUtils
-					.readByteChannel(
-							() -> Files.newByteChannel(this.file, StandardOpenOption.READ),
-							DefaultDataBufferFactory.sharedInstance, 1024)
-					.subscribeOn(PartGenerator.this.blockingOperationScheduler);
-		}
-
 		@Override
 		public void dispose() {
 			if (this.closeOnDispose) {

spring-web/src/main/java/org/springframework/http/codec/multipart/SynchronossPartHttpMessageReader.java

@@ -16,7 +16,9 @@
 
 package org.springframework.http.codec.multipart;
 
+import java.io.File;
 import java.io.IOException;
+import java.io.InputStream;
 import java.nio.channels.Channels;
 import java.nio.channels.FileChannel;
 import java.nio.channels.ReadableByteChannel;
@@ -40,6 +42,7 @@
 import org.synchronoss.cloud.nio.multipart.NioMultipartParser;
 import org.synchronoss.cloud.nio.multipart.NioMultipartParserListener;
 import org.synchronoss.cloud.nio.multipart.PartBodyStreamStorageFactory;
+import org.synchronoss.cloud.nio.stream.storage.NameAwarePurgableFileInputStream;
 import org.synchronoss.cloud.nio.stream.storage.StreamStorage;
 import reactor.core.publisher.BaseSubscriber;
 import reactor.core.publisher.Flux;
@@ -497,6 +500,38 @@ public Flux<DataBuffer> content() {
 		protected StreamStorage getStorage() {
 			return this.storage;
 		}
+
+		@Override
+		public Mono<Void> delete() {
+			return Mono.fromRunnable(() -> {
+				File file = getFile();
+				if (file != null) {
+					file.delete();
+				}
+			});
+		}
+
+		@Nullable
+		private File getFile() {
+			InputStream inputStream = null;
+			try {
+				inputStream = getStorage().getInputStream();
+				if (inputStream instanceof NameAwarePurgableFileInputStream) {
+					NameAwarePurgableFileInputStream stream = (NameAwarePurgableFileInputStream) inputStream;
+					return stream.getFile();
+				}
+			}
+			finally {
+				if (inputStream != null) {
+					try {
+						inputStream.close();
+					}
+					catch (IOException ignore) {
+					}
+				}
+			}
+			return null;
+		}
 	}