Merge pull request EMCECS#9 from EMCECS/feature-zero-byte-speedup

Feature zero byte speedup

Author: DavidASeibert

readingTools/build.gradle

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2017 EMC Corporation. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0.txt
+ *
+ * or in the "license" file accompanying this file. This file 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.
+ */
+description = 'nfsclient readingTools jar - provides utility commands to test reading performance.'
+
+ext.mainClass = 'com.emc.ecs.nfsclient.nfs.io.FileReadingTest'
+
+buildscript {
+    apply from: "$commonBuildDir/ecs-tool.buildscript.gradle", to: buildscript
+}
+
+apply from: "$commonBuildDir/ecs-tool.subproject.gradle"
+
+dependencies {
+    compile project(':')
+    testRuntime "org.slf4j:slf4j-simple:1.7.5"
+    testCompile project(':').sourceSets.test.output,
+                "junit:junit:4.11"
+}

readingTools/src/main/java/com/emc/ecs/nfsclient/nfs/io/FileReadingTest.java

@@ -0,0 +1,99 @@
+/**
+ * Copyright 2017 EMC Corporation. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License").
+ * You may not use this file except in compliance with the License.
+ * A copy of the License is located at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0.txt
+ *
+ * or in the "license" file accompanying this file. This file 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 com.emc.ecs.nfsclient.nfs.io;
+
+import java.io.IOException;
+
+import com.emc.ecs.nfsclient.nfs.NfsReadResponse;
+import com.emc.ecs.nfsclient.nfs.nfs3.Nfs3;
+import com.emc.ecs.nfsclient.rpc.CredentialUnix;
+
+/**
+ * @author seibed
+ *
+ */
+public class FileReadingTest {
+
+    public static void main(String[] args) {
+        String export = args[0];
+        String fileName = args[1];
+        boolean useStream = Boolean.valueOf(args[2]);
+        try {
+            if (useStream) {
+                testStreamReading(export, fileName);
+            } else {
+                testReading(export, fileName);
+            }
+        } catch (Exception e) {
+            System.out.println(e.getMessage());
+            e.printStackTrace();
+        }
+    }
+
+    public static void testStreamReading(String export, String fileName)
+            throws Exception {
+        Nfs3 nfs3 = new Nfs3(export, new CredentialUnix(0, 0, null), 3);
+        NfsFileInputStream inputStream = null;
+        try {
+            NfsFile nfsFile = new Nfs3File(nfs3, fileName);
+            int fileLength = (int) nfsFile.length();
+            inputStream = new NfsFileInputStream(nfsFile);
+            byte[] buffer = new byte[fileLength];
+            System.out.println("Testing stream reading");
+            int bytesRead = inputStream.read(buffer);
+            if (NfsFileInputStream.EOF != inputStream.read()) {
+                throw new Exception("Reading error - should have been at the end of the file");
+            }
+            if (fileLength != bytesRead) {
+                throw new Exception("Reading error - read " + bytesRead
+                        + " bytes, should have been " + fileLength);
+            }
+            System.out.println("Success!");
+        } catch (Exception e) {
+            System.out.println(e.getMessage());
+        } finally {
+            if (inputStream != null) {
+                try {
+                    inputStream.close();
+                } catch (IOException e) {
+                    // e.printStackTrace();
+                }
+            }
+        }
+    }
+
+    public static void testReading(String export, String fileName)
+            throws Exception {
+        Nfs3 nfs3 = new Nfs3(export, new CredentialUnix(0, 0, null), 3);
+        try {
+            NfsFile nfsFile = new Nfs3File(nfs3, fileName);
+            int fileLength = (int) nfsFile.length();
+            byte[] buffer = new byte[fileLength];
+            System.out.println("Testing with plain read");
+            NfsReadResponse response = nfsFile.read(0, buffer.length, buffer, 0);
+            if (!response.isEof()) {
+                throw new Exception("Reading error - should have been at the end of the file");
+            }
+            if (fileLength != response.getBytesRead()) {
+                throw new Exception("Reading error - read " + response.getBytesRead()
+                        + " bytes, should have been " + fileLength);
+            }
+            System.out.println("Success!");
+        } catch (Exception e) {
+            System.out.println(e.getMessage());
+        }
+    }
+
+}

settings.gradle

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 EMC Corporation. All Rights Reserved.
+ * Copyright 2016-2017 EMC Corporation. All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License").
  * You may not use this file except in compliance with the License.
@@ -14,3 +14,4 @@
  */
 rootProject.name = 'nfs-client'
 include 'tools'
+include 'readingTools'

src/main/java/com/emc/ecs/nfsclient/nfs/io/NfsFileInputStream.java

@@ -166,6 +166,9 @@ public NfsFileInputStream(NfsFile<?, ?> nfsFile) throws IOException {
      */
     private byte[] makeBytes(int maximumBufferSize) throws IOException {
         int bufferSize = Math.min((int) Math.min(_file.length() - _offset, Integer.MAX_VALUE), maximumBufferSize);
+        if (bufferSize == 0) {
+            _isEof = true;
+        }
         return new byte[bufferSize];
     }
 
@@ -322,11 +325,15 @@ private void checkForClosed() throws IOException {
     }
 
     /**
-     * If the buffer has no more bytes to be read, load more bytes.
+     * If the buffer has no more bytes to be read, and there are bytes available in the file, load more bytes.
      * 
      * @throws IOException
      */
     private void loadBytesAsNeeded() throws IOException {
+        if (available() <= 0) {
+            _isEof = true;
+        }
+
         while ((!_isEof) && (bytesLeftInBuffer() <= 0)) {
             _currentBufferPosition = 0;
             NfsReadResponse response = _file.read(_offset, _bytes.length, _bytes, _currentBufferPosition);