Merge pull request googleapis#15 from shinfan/master

Port LocalServiceHelper into GAX

src/main/java/com/google/api/gax/testing/CommandWrapper.java

@@ -0,0 +1,103 @@
+/*
+ * Copyright 2015 Google Inc. 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.
+ * 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 com.google.api.gax.testing;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Locale;
+
+/* Utility class that executes system commands on both Windows and Unix */
+public class CommandWrapper {
+  private final List<String> prefix;
+  private List<String> command;
+  private String nullFilename;
+  private boolean redirectOutputToNull;
+  private boolean redirectErrorStream;
+  private boolean redirectErrorInherit;
+  private Path directory;
+
+  private CommandWrapper() {
+    this.prefix = new ArrayList<>();
+    if (isWindows()) {
+      this.prefix.add("cmd");
+      this.prefix.add("/C");
+      this.nullFilename = "NUL:";
+    } else {
+      this.prefix.add("bash");
+      this.nullFilename = "/dev/null";
+    }
+  }
+
+  public CommandWrapper command(List<String> command) {
+    this.command = new ArrayList<>(command.size() + this.prefix.size());
+    this.command.addAll(prefix);
+    this.command.addAll(command);
+    return this;
+  }
+
+  public CommandWrapper redirectOutputToNull() {
+    this.redirectOutputToNull = true;
+    return this;
+  }
+
+  public CommandWrapper redirectErrorStream() {
+    this.redirectErrorStream = true;
+    return this;
+  }
+
+  public CommandWrapper redirectErrorInherit() {
+    this.redirectErrorInherit = true;
+    return this;
+  }
+
+  public CommandWrapper directory(Path directory) {
+    this.directory = directory;
+    return this;
+  }
+
+  public ProcessBuilder builder() {
+    ProcessBuilder builder = new ProcessBuilder(command);
+    if (redirectOutputToNull) {
+      builder.redirectOutput(new File(nullFilename));
+    }
+    if (directory != null) {
+      builder.directory(directory.toFile());
+    }
+    if (redirectErrorStream) {
+      builder.redirectErrorStream(true);
+    }
+    if (redirectErrorInherit) {
+      builder.redirectError(ProcessBuilder.Redirect.INHERIT);
+    }
+    return builder;
+  }
+
+  public Process start() throws IOException {
+    return builder().start();
+  }
+
+  public static CommandWrapper create() {
+    return new CommandWrapper();
+  }
+
+  public static boolean isWindows() {
+    return System.getProperty("os.name").toLowerCase(Locale.ENGLISH).contains("windows");
+  }
+}

src/main/java/com/google/api/gax/testing/DownloadableEmulatorRunner.java

@@ -0,0 +1,166 @@
+/*
+ * Copyright 2015 Google Inc. 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.
+ * 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 com.google.api.gax.testing;
+
+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.InputStream;
+import java.math.BigInteger;
+import java.net.URL;
+import java.nio.channels.Channels;
+import java.nio.channels.ReadableByteChannel;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
+
+/**
+ * Utility class to start and run an emulator from a download URL.
+ */
+public class DownloadableEmulatorRunner implements EmulatorRunner {
+  private final List<String> commandText;
+  private final String md5CheckSum;
+  private final URL downloadUrl;
+  private final String fileName;
+  private Process process;
+  private static final Logger log = Logger.getLogger(DownloadableEmulatorRunner.class.getName());
+
+  public DownloadableEmulatorRunner(List<String> commandText, URL downloadUrl, String md5CheckSum) {
+    this.commandText = commandText;
+    this.md5CheckSum = md5CheckSum;
+    this.downloadUrl = downloadUrl;
+    String[] splitUrl = downloadUrl.toString().split("/");
+    this.fileName = splitUrl[splitUrl.length - 1];
+  }
+
+  @Override
+  public boolean isAvailable() {
+    try {
+      downloadZipFile();
+      return true;
+    } catch (IOException e) {
+      return false;
+    }
+  }
+
+  @Override
+  public void start() throws IOException {
+    Path emulatorPath = downloadEmulator();
+    process = CommandWrapper.create()
+        .command(commandText)
+        .directory(emulatorPath)
+        .start();
+  }
+
+  @Override
+  public void stop() throws InterruptedException {
+    if (process != null) {
+      process.destroy();
+      process.waitFor();
+    }
+  }
+
+  @Override
+  public Process getProcess() {
+    return process;
+  }
+
+  private Path downloadEmulator() throws IOException {
+    // Retrieve the file name from the download link
+    String[] splittedUrl = downloadUrl.toString().split("/");
+    String fileName = splittedUrl[splittedUrl.length - 1];
+
+    // Each run is associated with its own folder that is deleted once test completes.
+    Path emulatorPath = Files.createTempDirectory(fileName.split("\\.")[0]);
+    File emulatorFolder = emulatorPath.toFile();
+    emulatorFolder.deleteOnExit();
+
+    File zipFile = downloadZipFile();
+    // Unzip the emulator
+    try (ZipInputStream zipIn = new ZipInputStream(new FileInputStream(zipFile))) {
+      if (log.isLoggable(Level.FINE)) {
+        log.fine("Unzipping emulator");
+      }
+      ZipEntry entry = zipIn.getNextEntry();
+      while (entry != null) {
+        File filePath = new File(emulatorPath.toFile(), entry.getName());
+        if (!entry.isDirectory()) {
+          extractFile(zipIn, filePath);
+        } else {
+          filePath.mkdir();
+        }
+        zipIn.closeEntry();
+        entry = zipIn.getNextEntry();
+      }
+    }
+    return emulatorPath;
+  }
+
+  private File downloadZipFile() throws IOException {
+    // Check if we already have a local copy of the emulator and download it if not.
+    File zipFile = new File(System.getProperty("java.io.tmpdir"), fileName);
+    if (!zipFile.exists() || (md5CheckSum != null && !md5CheckSum.equals(md5(zipFile)))) {
+      if (log.isLoggable(Level.FINE)) {
+        log.fine("Fetching emulator");
+      }
+      ReadableByteChannel rbc = Channels.newChannel(downloadUrl.openStream());
+      try (FileOutputStream fos = new FileOutputStream(zipFile)) {
+        fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+      }
+    } else {
+      if (log.isLoggable(Level.FINE)) {
+        log.fine("Using cached emulator");
+      }
+    }
+    return zipFile;
+  }
+
+  private void extractFile(ZipInputStream zipIn, File filePath) throws IOException {
+    try (BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(filePath))) {
+      byte[] bytesIn = new byte[1024];
+      int read;
+      while ((read = zipIn.read(bytesIn)) != -1) {
+        bos.write(bytesIn, 0, read);
+      }
+    }
+  }
+
+  private static String md5(File zipFile) throws IOException {
+    try {
+      MessageDigest md5 = MessageDigest.getInstance("MD5");
+      try (InputStream is = new BufferedInputStream(new FileInputStream(zipFile))) {
+        byte[] bytes = new byte[4 * 1024 * 1024];
+        int len;
+        while ((len = is.read(bytes)) >= 0) {
+          md5.update(bytes, 0, len);
+        }
+      }
+      return String.format("%032x", new BigInteger(1, md5.digest()));
+    } catch (NoSuchAlgorithmException e) {
+      throw new IOException(e);
+    }
+  }
+}

src/main/java/com/google/api/gax/testing/EmulatorRunner.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2015 Google Inc. 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.
+ * 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 com.google.api.gax.testing;
+
+import java.io.IOException;
+
+/**
+ * Utility interface to start and run an emulator.
+ */
+public interface EmulatorRunner {
+  public boolean isAvailable();
+  public void start() throws IOException;
+  public void stop() throws InterruptedException;
+  public Process getProcess();
+}