RATIS-1900. Do not use FileInputStream/FileOutputStream.

pom.xml

@@ -184,6 +184,7 @@
     <build-helper-maven-plugin.version>3.3.0</build-helper-maven-plugin.version>
     <exec-maven-plugin.version>3.1.0</exec-maven-plugin.version>
     <extra-enforcer-rules.version>1.6.1</extra-enforcer-rules.version>
+    <restrict-imports-enforcer-rules.version>2.4.0</restrict-imports-enforcer-rules.version>
     <license-maven-plugin.version>2.2.0</license-maven-plugin.version>
 
     <protobuf-maven-plugin.version>0.6.1</protobuf-maven-plugin.version>
@@ -529,7 +530,36 @@
               </requireJavaVersion>
             </rules>
           </configuration>
+          <dependencies>
+            <dependency>
+              <groupId>de.skuzzle.enforcer</groupId>
+              <artifactId>restrict-imports-enforcer-rule</artifactId>
+              <version>${restrict-imports-enforcer-rules.version}</version>
+            </dependency>
+          </dependencies>
+          <executions>
+            <execution>
+              <id>bannedImports-finalizers</id>
+              <phase>process-sources</phase>
+              <goals>
+                <goal>enforce</goal>
+              </goals>
+              <configuration>
+                <rules>
+                  <restrictImports>
+                    <includeTestCode>false</includeTestCode>
+                    <reason>Classes (e.g. FileInputStream, FileOutputStream) overriding the Object.finalize() method will cause gc to run a much longer time. As stated in Effective Java, there is a severe performance penalty for using finalizers.</reason>
+                    <bannedImports>
+                      <bannedImport>java.io.FileInputStream</bannedImport>
+                      <bannedImport>java.io.FileOutputStream</bannedImport>
+                    </bannedImports>
+                  </restrictImports>
+                </rules>
+              </configuration>
+            </execution>
+          </executions>
         </plugin>
+
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-assembly-plugin</artifactId>

ratis-common/src/main/java/org/apache/ratis/protocol/RaftId.java

@@ -20,7 +20,7 @@
 import org.apache.ratis.thirdparty.com.google.common.cache.Cache;
 import org.apache.ratis.thirdparty.com.google.common.cache.CacheBuilder;
 import org.apache.ratis.thirdparty.com.google.protobuf.ByteString;
-import org.apache.ratis.thirdparty.com.google.protobuf.ByteStringUtils;
+import org.apache.ratis.thirdparty.com.google.protobuf.UnsafeByteOperations;
 import org.apache.ratis.util.JavaUtils;
 import org.apache.ratis.util.Preconditions;
 
@@ -49,7 +49,7 @@ static ByteString toByteString(UUID uuid) {
     ByteBuffer.wrap(array)
         .putLong(uuid.getMostSignificantBits())
         .putLong(uuid.getLeastSignificantBits());
-    return ByteStringUtils.unsafeWrap(array);
+    return UnsafeByteOperations.unsafeWrap(array);
   }
 
   abstract static class Factory<ID extends RaftId> {

ratis-examples/src/main/java/org/apache/ratis/examples/arithmetic/ArithmeticStateMachine.java

@@ -34,14 +34,13 @@
 import org.apache.ratis.statemachine.impl.SimpleStateMachineStorage;
 import org.apache.ratis.statemachine.impl.SingleFileSnapshotInfo;
 import org.apache.ratis.util.AutoCloseableLock;
+import org.apache.ratis.util.FileUtils;
 import org.apache.ratis.util.JavaUtils;
 import org.apache.ratis.util.MD5FileUtil;
 
 import java.io.BufferedInputStream;
 import java.io.BufferedOutputStream;
 import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
@@ -97,8 +96,8 @@ public long takeSnapshot() {
     final File snapshotFile =  storage.getSnapshotFile(last.getTerm(), last.getIndex());
     LOG.info("Taking a snapshot to file {}", snapshotFile);
 
-    try(ObjectOutputStream out = new ObjectOutputStream(
-        new BufferedOutputStream(new FileOutputStream(snapshotFile)))) {
+    try(ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(
+        FileUtils.newOutputStream(snapshotFile)))) {
       out.writeObject(copy);
     } catch(IOException ioe) {
       LOG.warn("Failed to write snapshot file \"" + snapshotFile
@@ -130,8 +129,8 @@ public long loadSnapshot(SingleFileSnapshotInfo snapshot) throws IOException {
 
     final TermIndex last = SimpleStateMachineStorage.getTermIndexFromSnapshotFile(snapshotFile);
     try(AutoCloseableLock writeLock = writeLock();
-        ObjectInputStream in = new ObjectInputStream(
-            new BufferedInputStream(new FileInputStream(snapshotFile)))) {
+        ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(
+            FileUtils.newInputStream(snapshotFile)))) {
       reset();
       setLastAppliedTermIndex(last);
       variables.putAll(JavaUtils.cast(in.readObject()));

ratis-examples/src/main/java/org/apache/ratis/examples/common/Constants.java

@@ -21,14 +21,12 @@
 import org.apache.ratis.protocol.RaftGroup;
 import org.apache.ratis.protocol.RaftGroupId;
 import org.apache.ratis.protocol.RaftPeer;
+import org.apache.ratis.util.FileUtils;
 import org.apache.ratis.util.TimeDuration;
 
 import java.io.BufferedReader;
-import java.io.FileInputStream;
 import java.io.IOException;
-import java.io.InputStream;
 import java.io.InputStreamReader;
-import java.io.Reader;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -52,10 +50,9 @@ public final class Constants {
   static {
     final Properties properties = new Properties();
     final String conf = "ratis-examples/src/main/resources/conf.properties";
-    try(InputStream inputStream = new FileInputStream(conf);
-        Reader reader = new InputStreamReader(inputStream, StandardCharsets.UTF_8);
-        BufferedReader bufferedReader = new BufferedReader(reader)) {
-      properties.load(bufferedReader);
+    try(BufferedReader in = new BufferedReader(new InputStreamReader(
+        FileUtils.newInputStream(conf), StandardCharsets.UTF_8))) {
+      properties.load(in);
     } catch (IOException e) {
       throw new IllegalStateException("Failed to load " + conf, e);
     }

ratis-examples/src/main/java/org/apache/ratis/examples/filestore/cli/DataStream.java

@@ -1,4 +1,4 @@
-/**
+/*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
@@ -26,14 +26,15 @@
 import org.apache.ratis.protocol.RoutingTable;
 import org.apache.ratis.thirdparty.io.netty.buffer.ByteBuf;
 import org.apache.ratis.thirdparty.io.netty.buffer.PooledByteBufAllocator;
+import org.apache.ratis.util.FileUtils;
 import org.apache.ratis.util.JavaUtils;
 import org.apache.ratis.util.Preconditions;
 
 import java.io.File;
-import java.io.FileInputStream;
 import java.io.IOException;
 import java.nio.MappedByteBuffer;
 import java.nio.channels.FileChannel;
+import java.nio.file.StandardOpenOption;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -238,8 +239,7 @@ List<CompletableFuture<DataStreamReply>> transfer(
 
       final List<CompletableFuture<DataStreamReply>> futures = new ArrayList<>();
       final DataStreamOutput out = client.getStreamOutput(file.getName(), fileSize, routingTable);
-      try (FileInputStream fis = new FileInputStream(file)) {
-        final FileChannel in = fis.getChannel();
+      try (FileChannel in = FileUtils.newFileChannel(file, StandardOpenOption.READ)) {
         for (long offset = 0L; offset < fileSize; ) {
           offset += write(in, out, offset, futures);
         }

ratis-examples/src/main/java/org/apache/ratis/examples/filestore/cli/LoadGen.java

@@ -1,4 +1,4 @@
-/**
+/*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
@@ -22,11 +22,12 @@
 import org.apache.ratis.examples.filestore.FileStoreClient;
 import org.apache.ratis.thirdparty.io.netty.buffer.ByteBuf;
 import org.apache.ratis.thirdparty.io.netty.buffer.PooledByteBufAllocator;
+import org.apache.ratis.util.FileUtils;
 
 import java.io.File;
-import java.io.FileInputStream;
 import java.io.IOException;
 import java.nio.channels.FileChannel;
+import java.nio.file.StandardOpenOption;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
@@ -97,8 +98,7 @@ private Map<String, CompletableFuture<List<CompletableFuture<Long>>>> writeByHea
       CompletableFuture.supplyAsync(() -> {
         List<CompletableFuture<Long>> futures = new ArrayList<>();
         File file = new File(path);
-        try (FileInputStream fis = new FileInputStream(file)) {
-          final FileChannel in = fis.getChannel();
+        try (FileChannel in = FileUtils.newFileChannel(file, StandardOpenOption.READ)) {
           for (long offset = 0L; offset < getFileSizeInBytes(); ) {
             offset += write(in, offset, client, file.getName(), futures);
           }

ratis-server/src/main/java/org/apache/ratis/server/raftlog/segmented/SegmentedRaftLogReader.java

@@ -19,12 +19,13 @@
 
 import org.apache.ratis.io.CorruptedFileException;
 import org.apache.ratis.metrics.Timekeeper;
+import org.apache.ratis.proto.RaftProtos.LogEntryProto;
 import org.apache.ratis.protocol.exceptions.ChecksumException;
 import org.apache.ratis.server.metrics.SegmentedRaftLogMetrics;
 import org.apache.ratis.server.raftlog.RaftLog;
 import org.apache.ratis.thirdparty.com.google.protobuf.CodedInputStream;
 import org.apache.ratis.thirdparty.com.google.protobuf.CodedOutputStream;
-import org.apache.ratis.proto.RaftProtos.LogEntryProto;
+import org.apache.ratis.util.FileUtils;
 import org.apache.ratis.util.IOUtils;
 import org.apache.ratis.util.Preconditions;
 import org.apache.ratis.util.PureJavaCrc32C;
@@ -33,15 +34,22 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.io.*;
+import java.io.BufferedInputStream;
+import java.io.Closeable;
+import java.io.DataInputStream;
+import java.io.EOFException;
+import java.io.File;
+import java.io.FilterInputStream;
+import java.io.IOException;
+import java.io.InputStream;
 import java.util.Optional;
 import java.util.zip.Checksum;
 
 class SegmentedRaftLogReader implements Closeable {
   static final Logger LOG = LoggerFactory.getLogger(SegmentedRaftLogReader.class);
   /**
    * InputStream wrapper that keeps track of the current stream position.
-   *
+   * <p>
    * This stream also allows us to set a limit on how many bytes we can read
    * without getting an exception.
    */
@@ -141,11 +149,9 @@ public long skip(long amt) throws IOException {
   private final SegmentedRaftLogMetrics raftLogMetrics;
   private final SizeInBytes maxOpSize;
 
-  SegmentedRaftLogReader(File file, SizeInBytes maxOpSize, SegmentedRaftLogMetrics raftLogMetrics)
-      throws FileNotFoundException {
+  SegmentedRaftLogReader(File file, SizeInBytes maxOpSize, SegmentedRaftLogMetrics raftLogMetrics) throws IOException {
     this.file = file;
-    this.limiter = new LimitedInputStream(
-        new BufferedInputStream(new FileInputStream(file)));
+    this.limiter = new LimitedInputStream(new BufferedInputStream(FileUtils.newInputStream(file)));
     in = new DataInputStream(limiter);
     checksum = new PureJavaCrc32C();
     this.maxOpSize = maxOpSize;
@@ -154,13 +160,10 @@ public long skip(long amt) throws IOException {
 
   /**
    * Read header from the log file:
-   *
    * (1) The header in file is verified successfully.
    *     Then, return true.
-   *
    * (2) The header in file is partially written.
    *     Then, return false.
-   *
    * (3) The header in file is corrupted or there is some other {@link IOException}.
    *     Then, throw an exception.
    */
@@ -197,7 +200,7 @@ LogEntryProto readEntry() throws IOException {
     final Timekeeper timekeeper = Optional.ofNullable(raftLogMetrics)
         .map(SegmentedRaftLogMetrics::getReadEntryTimer)
         .orElse(null);
-    try(AutoCloseable readEntryContext = Timekeeper.start(timekeeper)) {
+    try(AutoCloseable ignored = Timekeeper.start(timekeeper)) {
       return decodeEntry();
     } catch (EOFException eof) {
       in.reset();

ratis-server/src/main/java/org/apache/ratis/server/storage/FileChunkReader.java

@@ -21,12 +21,12 @@
 import org.apache.ratis.proto.RaftProtos.FileChunkProto;
 import org.apache.ratis.thirdparty.com.google.protobuf.ByteString;
 import org.apache.ratis.thirdparty.com.google.protobuf.UnsafeByteOperations;
+import org.apache.ratis.util.FileUtils;
 import org.apache.ratis.util.IOUtils;
 import org.apache.ratis.util.JavaUtils;
 
 import java.io.Closeable;
 import java.io.File;
-import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.file.Path;
@@ -57,13 +57,19 @@ public FileChunkReader(FileInfo info, Path relativePath) throws IOException {
     final File f = info.getPath().toFile();
     if (info.getFileDigest() == null) {
       digester = MD5Hash.getDigester();
-      this.in = new DigestInputStream(new FileInputStream(f), digester);
+      this.in = new DigestInputStream(FileUtils.newInputStream(f), digester);
     } else {
       digester = null;
-      this.in = new FileInputStream(f);
+      this.in = FileUtils.newInputStream(f);
     }
   }
 
+  static ByteString readFileChunk(int chunkLength, InputStream in) throws IOException {
+    final byte[] chunkBuffer = new byte[chunkLength];
+    IOUtils.readFully(in, chunkBuffer, 0, chunkBuffer.length);
+    return UnsafeByteOperations.unsafeWrap(chunkBuffer);
+  }
+
   /**
    * Read the next chunk.
    *
@@ -74,9 +80,7 @@ public FileChunkReader(FileInfo info, Path relativePath) throws IOException {
   public FileChunkProto readFileChunk(int chunkMaxSize) throws IOException {
     final long remaining = info.getFileSize() - offset;
     final int chunkLength = remaining < chunkMaxSize ? (int) remaining : chunkMaxSize;
-    final byte[] chunkBuffer = new byte[chunkLength];
-    IOUtils.readFully(in, chunkBuffer, 0, chunkBuffer.length);
-    final ByteString data = UnsafeByteOperations.unsafeWrap(chunkBuffer);
+    final ByteString data = readFileChunk(chunkLength, in);
     // whether this chunk is the last chunk of current file
     final boolean isDone = offset + chunkLength == info.getFileSize();
     final ByteString fileDigest;