Add BaseEmulatorHelper class and tests, refactor helper classes

google-cloud-core/src/main/java/com/google/cloud/testing/BlockingProcessStreamReader.java

@@ -0,0 +1,158 @@
+/*
+ * Copyright 2016 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.cloud.testing;
+
+import static com.google.common.base.MoreObjects.firstNonNull;
+
+import com.google.common.base.Strings;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * This class allows to read a process output stream, block until a provided string appears on the
+ * stream and redirect pertinent error logs to a provided logger.
+ */
+class BlockingProcessStreamReader extends Thread {
+
+  private static final int STREAM_READER_SLEEP_INTERVAL_IN_MS = 200;
+  private static final int LOG_LENGTH_LIMIT = 50000;
+
+  private final BufferedReader errorReader;
+  private final Logger logger;
+  private StringBuilder currentLog;
+  private Level currentLogLevel;
+  private boolean collectionMode;
+  private volatile boolean terminated;
+  private final String emulatorTag;
+  private final Pattern logLinePattern;
+
+  private BlockingProcessStreamReader(String emulator, InputStream stream, String blockUntil,
+      Logger logger) throws IOException {
+    super("blocking-process-stream-reader");
+    setDaemon(true);
+    errorReader = new BufferedReader(new InputStreamReader(stream));
+    this.logger = logger;
+    this.emulatorTag = "[" + emulator + "]";
+    this.logLinePattern = Pattern.compile("(\\[" + emulator + "\\]\\s)?(\\w+):.*");
+    if (!Strings.isNullOrEmpty(blockUntil)) {
+      String line;
+      do {
+        line = errorReader.readLine();
+      } while (line != null && !line.contains(blockUntil));
+    }
+  }
+
+  void terminate() throws IOException {
+    terminated = true;
+    errorReader.close();
+    interrupt();
+  }
+
+  @Override
+  public void run() {
+    String previousLine = "";
+    String nextLine = "";
+    while (!terminated) {
+      try {
+        if (errorReader.ready()) {
+          previousLine = nextLine;
+          nextLine = errorReader.readLine();
+          if (nextLine == null) {
+            terminated = true;
+          } else {
+            processLogLine(previousLine, nextLine);
+          }
+        } else {
+          sleep(STREAM_READER_SLEEP_INTERVAL_IN_MS);
+        }
+      } catch (IOException e) {
+        e.printStackTrace(System.err);
+      } catch (InterruptedException e) {
+        previousLine = nextLine;
+        nextLine = null;
+        break;
+      }
+    }
+    processLogLine(previousLine, firstNonNull(nextLine, ""));
+    writeLog();
+  }
+
+  private void processLogLine(String previousLine, String nextLine) {
+    // Each log is two lines with the following format:
+    //     [Emulator]? [Date] [Time] [LoggingClass] [method]
+    //     [Emulator]? [LEVEL]: error message
+    //     [Emulator]? more data
+    // Exceptions and stack traces are included in error stream, separated by a newline
+    Level nextLogLevel = getLevel(nextLine);
+    if (nextLogLevel != null) {
+      writeLog();
+      currentLog = new StringBuilder();
+      currentLogLevel = nextLogLevel;
+      collectionMode = true;
+    } else if (collectionMode) {
+      if (currentLog.length() > LOG_LENGTH_LIMIT) {
+        collectionMode = false;
+      } else if (currentLog.length() == 0) {
+        // strip level out of the line
+        currentLog.append(emulatorTag);
+        currentLog.append(previousLine.split(":", 2)[1]);
+        currentLog.append(System.getProperty("line.separator"));
+      } else {
+        if (!previousLine.startsWith(emulatorTag)) {
+          currentLog.append(emulatorTag);
+          currentLog.append(' ');
+        }
+        currentLog.append(previousLine);
+        currentLog.append(System.getProperty("line.separator"));
+      }
+    }
+  }
+
+  private void writeLog() {
+    if (currentLogLevel != null && currentLog != null && currentLog.length() != 0) {
+      logger.log(currentLogLevel, currentLog.toString().trim());
+    }
+  }
+
+  private Level getLevel(String line) {
+    try {
+      Matcher matcher = logLinePattern.matcher(line);
+      if (matcher.matches()) {
+        return Level.parse(matcher.group(2));
+      } else {
+        return null;
+      }
+    } catch (IllegalArgumentException e) {
+      return null; // level wasn't supplied in this log line
+    }
+  }
+
+  static BlockingProcessStreamReader start(String emulator, InputStream stream, String blockUntil,
+      Logger logger) throws IOException {
+    BlockingProcessStreamReader thread =
+        new BlockingProcessStreamReader(emulator, stream, blockUntil, logger);
+    thread.start();
+    return thread;
+  }
+}

google-cloud-core/src/main/java/com/google/cloud/testing/CommandWrapper.java

@@ -0,0 +1,101 @@
+/*
+ * Copyright 2016 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.cloud.testing;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Utility class that executes system commands on both Windows and Unix.
+ */
+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 (BaseEmulatorHelper.isWindows()) {
+      this.prefix.add("cmd");
+      this.prefix.add("/C");
+      this.nullFilename = "NUL:";
+    } else {
+      this.prefix.add("bash");
+      this.nullFilename = "/dev/null";
+    }
+  }
+
+  CommandWrapper setCommand(List<String> command) {
+    this.command = new ArrayList<>(command.size() + this.prefix.size());
+    this.command.addAll(prefix);
+    this.command.addAll(command);
+    return this;
+  }
+
+  CommandWrapper setRedirectOutputToNull() {
+    this.redirectOutputToNull = true;
+    return this;
+  }
+
+  CommandWrapper setRedirectErrorStream() {
+    this.redirectErrorStream = true;
+    return this;
+  }
+
+  CommandWrapper setRedirectErrorInherit() {
+    this.redirectErrorInherit = true;
+    return this;
+  }
+
+  CommandWrapper setDirectory(Path directory) {
+    this.directory = directory;
+    return this;
+  }
+
+  ProcessBuilder getBuilder() {
+    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 getBuilder().start();
+  }
+
+  static CommandWrapper create() {
+    return new CommandWrapper();
+  }
+}

google-cloud-core/src/main/java/com/google/cloud/testing/Version.java

@@ -0,0 +1,92 @@
+/*
+ * Copyright 2016 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.cloud.testing;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Objects;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * Simplified wrapper for emulator's versions.
+ */
+class Version implements Comparable<Version> {
+
+  private static final Pattern VERSION_PATTERN = Pattern.compile("^(\\d+)\\.(\\d+)\\.(\\d+)$");
+
+  private final int major;
+  private final int minor;
+  private final int patch;
+
+  private Version(int major, int minor, int patch) {
+    this.major = major;
+    this.minor = minor;
+    this.patch = patch;
+  }
+
+  @Override
+  public int compareTo(Version version) {
+    int result = major - version.major;
+    if (result == 0) {
+      result = minor - version.minor;
+      if (result == 0) {
+        result = patch - version.patch;
+      }
+    }
+    return result;
+  }
+
+  @Override
+  public String toString() {
+    return String.format("%d.%d.%d", major, minor, patch);
+  }
+
+  @Override
+  public boolean equals(Object other) {
+    return this == other || other instanceof Version && compareTo((Version) other) == 0;
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(major, minor, patch);
+  }
+
+  int getMajor() {
+    return major;
+  }
+
+  int getMinor() {
+    return minor;
+  }
+
+  int getPatch() {
+    return patch;
+  }
+
+  static Version fromString(String version) {
+    Matcher matcher = VERSION_PATTERN.matcher(checkNotNull(version));
+    if (matcher.matches()) {
+      return new Version(
+          Integer.valueOf(matcher.group(1)),
+          Integer.valueOf(matcher.group(2)),
+          Integer.valueOf(matcher.group(3)));
+    }
+    throw new IllegalArgumentException("Invalid version format");
+  }
+}