Github user nkalmar commented on a diff in the pull request:
https://github.com/apache/zookeeper/pull/690#discussion_r232325666
--- Diff:
zookeeper-server/src/main/java/org/apache/zookeeper/server/persistence/SnapStream.java
---
@@ -0,0 +1,336 @@
+/**
+ * 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
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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
+ *
+ * http://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.apache.zookeeper.server.persistence;
+
+import java.io.BufferedInputStream;
+import java.io.BufferedOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.RandomAccessFile;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.zip.Adler32;
+import java.util.zip.CheckedInputStream;
+import java.util.zip.CheckedOutputStream;
+import java.util.zip.GZIPInputStream;
+import java.util.zip.GZIPOutputStream;
+
+import org.apache.jute.InputArchive;
+import org.apache.jute.OutputArchive;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.xerial.snappy.SnappyCodec;
+import org.xerial.snappy.SnappyInputStream;
+import org.xerial.snappy.SnappyOutputStream;
+
+/**
+ * Represent the Stream used in serialize and deserialize the Snapshot.
+ */
+public class SnapStream {
+
+ private static final Logger LOG =
LoggerFactory.getLogger(SnapStream.class);
+
+ public static final String ZOOKEEPER_SHAPSHOT_STREAM_MODE =
+ "zookeeper.snapshot.compression.method";
+
+ private static StreamMode streamMode =
+ StreamMode.fromString(
+ System.getProperty(ZOOKEEPER_SHAPSHOT_STREAM_MODE,
+ StreamMode.DEFAULT_MODE.getName()));
+
+ static {
+ LOG.info(ZOOKEEPER_SHAPSHOT_STREAM_MODE + "=" + streamMode);
+ }
+
+ public static enum StreamMode {
+ GZIP("gz"),
+ SNAPPY("snappy"),
+ CHECKED("");
+
+ public static final StreamMode DEFAULT_MODE = CHECKED;
+
+ private String name;
+
+ StreamMode(String name) {
+ this.name = name;
+ }
+
+ public String getName() {
+ return name;
+ }
+
+ public String getFileExtension() {
+ return name.isEmpty() ? "" : "." + name;
+ }
+
+ public static StreamMode fromString(String name) {
+ for (StreamMode c : values()) {
+ if (c.getName().compareToIgnoreCase(name) == 0) {
+ return c;
+ }
+ }
+ return DEFAULT_MODE;
+ }
+ }
+
+ /**
+ * Return the CheckedInputStream based on the extension of the
fileName.
+ *
+ * @param fileName the file the InputStream read from
+ * @return the specific InputStream
+ * @throws IOException
+ */
+ public static CheckedInputStream getInputStream(File file) throws
IOException {
+ FileInputStream fis = new FileInputStream(file);
+ InputStream is;
+ switch (getStreamMode(file.getName())) {
+ case GZIP:
+ is = new GZIPInputStream(fis);
+ break;
+ case SNAPPY:
+ is = new SnappyInputStream(fis);
+ break;
+ case CHECKED:
+ default:
+ is = new BufferedInputStream(fis);
+ }
+ return new CheckedInputStream(is, new Adler32());
+ }
+
+ /**
+ * Return the OutputStream based on predefined stream mode.
+ *
+ * @param fileName the file the OutputStream writes to
+ * @return the specific OutputStream
+ * @throws IOException
+ */
+ public static CheckedOutputStream getOutputStream(File file) throws
IOException {
+ FileOutputStream fos = new FileOutputStream(file);
+ OutputStream os;
+ switch (streamMode) {
+ case GZIP:
+ os = new GZIPOutputStream(fos);
+ break;
+ case SNAPPY:
+ os = new SnappyOutputStream(fos);
+ break;
+ case CHECKED:
+ default:
+ os = new BufferedOutputStream(fos);
+ }
+ return new CheckedOutputStream(os, new Adler32());
+ }
+
+ /**
+ * Write specific seal to the OutputArchive and close the OutputStream.
+ * Currently, only CheckedOutputStream will write it's checkSum to the
+ * end of the stream.
+ *
+ */
+ public static void sealStream(CheckedOutputStream os, OutputArchive oa)
+ throws IOException {
+ long val = os.getChecksum().getValue();
+ oa.writeLong(val, "val");
+ oa.writeString("/", "path");
+ }
+
+ /**
+ * Verify the integrity of the seal, only CheckedInputStream will
verify
+ * the checkSum of the content.
+ *
+ */
+ static void checkSealIntegrity(CheckedInputStream is, InputArchive ia)
+ throws IOException {
+ long checkSum = is.getChecksum().getValue();
+ long val = ia.readLong("val");
+ if (val != checkSum) {
+ throw new IOException("CRC corruption");
+ }
+ }
+
+ /**
+ * Verifies that the file is a valid snapshot. Snapshot may be invalid
if
+ * it's incomplete as in a situation when the server dies while in the
+ * process of storing a snapshot. Any files that are improperly
formated
+ * or corrupted are invalid. Any file that is not a snapshot is also an
+ * invalid snapshot.
+ *
+ * @param file file to verify
+ * @return true if the snapshot is valid
+ * @throws IOException
+ */
+ public static boolean isValidSnapshot(File file) throws IOException {
+ if (file == null || Util.getZxidFromName(file.getName(),
FileSnap.SNAPSHOT_FILE_PREFIX) == -1) {
+ return false;
+ }
+
+ String fileName = file.getName();
+ if (Util.getZxidFromName(fileName, "snapshot") == -1) {
+ return false;
+ }
+
+ boolean isValid = false;
+ switch (getStreamMode(fileName)) {
+ case GZIP:
+ isValid = isValidGZipStream(file);
+ break;
+ case SNAPPY:
+ isValid = isValidSnappyStream(file);
+ break;
+ case CHECKED:
+ default:
+ isValid = isValidCheckedStream(file);
+ }
+ return isValid;
+ }
+
+ public static void setStreamMode(StreamMode mode) {
+ streamMode = mode;
+ }
+
+ public static StreamMode getStreamMode() {
+ return streamMode;
+ }
+
+ /**
+ * Detect the stream mode from file name extension
+ *
+ * @param fileName
+ * @return
+ */
+ public static StreamMode getStreamMode(String fileName) {
+ String[] splitSnapName = fileName.split("\\.");
+
+ // Use file extension to detect format
+ if (splitSnapName.length > 1) {
+ String mode = splitSnapName[splitSnapName.length - 1];
+ return StreamMode.fromString(mode);
+ }
+
+ return StreamMode.CHECKED;
+ }
+
+ /**
+ * Certify the GZip stream integrity by checking the header
+ * for the GZip magic string
+ *
+ * @param f file to verify
+ * @return true if it has the correct GZip magic string
+ * @throws IOException
+ */
+ private static boolean isValidGZipStream(File f) throws IOException {
+ FileInputStream fis = null;
+ byte[] byteArray = new byte[2];
+
+ try {
+ fis = new FileInputStream(f);
+ fis.read(byteArray, 0, 2);
--- End diff --
Findbugs reports this, as you ignore the result of read().
Please add it to findbugsExcludeFile.xml to ignore it (or you can use
return value to check if the read was successful here, not necessary though).
---
