Adds SingleThreadedLogger to be able to keep a footer for where progress indication will go.

jib-plugins-common/src/main/java/com/google/cloud/tools/jib/plugins/common/AnsiLoggerWithFooter.java

@@ -0,0 +1,141 @@
+/*
+ * Copyright 2018 Google LLC.
+ *
+ * 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.tools.jib.plugins.common;
+
+import com.google.common.util.concurrent.Futures;
+import java.time.Duration;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+import java.util.function.Consumer;
+
+/**
+ * Keeps all log messages in a sequential, deterministic order along with an additional footer that
+ * always appears below log messages. This is intended to log both the messages and the footer to
+ * the same console.
+ *
+ * <p>Make sure to call {@link #shutDown} when finished.
+ */
+class AnsiLoggerWithFooter {
+
+  /** ANSI escape sequence for moving the cursor up one line. */
+  private static final String CURSOR_UP_SEQUENCE = "\033[1A";
+
+  /** ANSI escape sequence for erasing to end of display. */
+  private static final String ERASE_DISPLAY_BELOW = "\033[0J";
+
+  /** ANSI escape sequence for setting all further characters to bold. */
+  private static final String BOLD = "\033[1m";
+
+  /** ANSI escape sequence for setting all further characters to not bold. */
+  private static final String UNBOLD = "\033[0m";
+
+  private static final Duration EXECUTOR_SHUTDOWN_WAIT = Duration.ofSeconds(1);
+
+  private final ExecutorService executorService = Executors.newSingleThreadExecutor();
+
+  private final Consumer<String> plainLogger;
+
+  private List<String> footerLines = Collections.emptyList();
+
+  AnsiLoggerWithFooter(Consumer<String> plainLogger) {
+    this.plainLogger = plainLogger;
+  }
+
+  /** Shuts down the {@link #executorService}. */
+  public void shutDown() {
+    executorService.shutdown();
+  }
+
+  /** Waits for the {@link #executorService} to terminate. */
+  public void awaitTermination() {
+    try {
+      if (!executorService.awaitTermination(
+          EXECUTOR_SHUTDOWN_WAIT.getSeconds(), TimeUnit.SECONDS)) {
+        executorService.shutdownNow();
+      }
+    } catch (InterruptedException ex) {
+      Thread.currentThread().interrupt();
+    }
+  }
+
+  /**
+   * Runs {@code messageLogger} asynchronously.
+   *
+   * @param messageLogger the {@link Runnable} intended to synchronously log a message to the
+   *     console
+   * @return a {@link Future} to track completion
+   */
+  public Future<Void> log(Runnable messageLogger) {
+    return log(messageLogger, footerLines);
+  }
+
+  /**
+   * Sets the footer asynchronously. This will replace the previously-printed footer with the new
+   * {@code footerLines}.
+   *
+   * <p>The footer is printed in <strong>bold</strong>.
+   *
+   * @param footerLines the footer, with each line as an element (no newline at end)
+   * @return a {@link Future} to track completion
+   */
+  public Future<Void> setFooter(List<String> footerLines) {
+    if (footerLines.equals(this.footerLines)) {
+      return Futures.immediateFuture(null);
+    }
+
+    return log(() -> {}, footerLines);
+  }
+
+  private Future<Void> log(Runnable messageLogger, List<String> newFooterLines) {
+    return executorService.submit(
+        () -> {
+          StringBuilder plainLogBuilder = new StringBuilder();
+
+          // Moves the cursor up to the start of the footer.
+          // TODO: Optimize to single init.
+          for (int i = 0; i < this.footerLines.size(); i++) {
+            // Moves cursor up.
+            plainLogBuilder.append(CURSOR_UP_SEQUENCE);
+          }
+
+          // Erases everything below cursor.
+          plainLogBuilder.append(ERASE_DISPLAY_BELOW);
+
+          // Writes out logMessage and footer.
+          plainLogger.accept(plainLogBuilder.toString());
+          messageLogger.run();
+
+          if (newFooterLines.size() > 0) {
+            StringBuilder footerBuilder = new StringBuilder();
+            for (String newFooterLine : newFooterLines) {
+              footerBuilder.append(BOLD).append(newFooterLine).append(UNBOLD).append('\n');
+            }
+            // Removes last newline.
+            footerBuilder.setLength(footerBuilder.length() - 1);
+            plainLogger.accept(footerBuilder.toString());
+          }
+
+          this.footerLines = newFooterLines;
+
+          return null;
+        });
+  }
+}

jib-plugins-common/src/test/java/com/google/cloud/tools/jib/plugins/common/AnsiLoggerWithFooterTest.java

@@ -0,0 +1,102 @@
+/*
+ * Copyright 2018 Google LLC.
+ *
+ * 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.tools.jib.plugins.common;
+
+import java.time.Duration;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import org.junit.Assert;
+import org.junit.Test;
+
+/** Tests for {@link AnsiLoggerWithFooter}. */
+public class AnsiLoggerWithFooterTest {
+
+  private static final Duration FUTURE_TIMEOUT = Duration.ofSeconds(1);
+
+  private final StringBuilder logBuilder = new StringBuilder();
+  private final AnsiLoggerWithFooter testAnsiLoggerWithFooter =
+      new AnsiLoggerWithFooter(logBuilder::append);
+
+  @Test
+  public void testLog_noFooter() throws InterruptedException, ExecutionException, TimeoutException {
+    testAnsiLoggerWithFooter
+        .log(() -> logBuilder.append("message\n"))
+        .get(FUTURE_TIMEOUT.getSeconds(), TimeUnit.SECONDS);
+
+    Assert.assertEquals("\033[0Jmessage\n", logBuilder.toString());
+  }
+
+  @Test
+  public void testLog_sameFooter()
+      throws InterruptedException, ExecutionException, TimeoutException {
+    testAnsiLoggerWithFooter
+        .setFooter(Collections.singletonList("footer"))
+        .get(FUTURE_TIMEOUT.getSeconds(), TimeUnit.SECONDS);
+    testAnsiLoggerWithFooter
+        .log(() -> logBuilder.append("message\n"))
+        .get(FUTURE_TIMEOUT.getSeconds(), TimeUnit.SECONDS);
+    testAnsiLoggerWithFooter
+        .log(() -> logBuilder.append("another message\n"))
+        .get(FUTURE_TIMEOUT.getSeconds(), TimeUnit.SECONDS);
+
+    Assert.assertEquals(
+        "\033[0J"
+            + "\033[1mfooter\033[0m"
+            + "\033[1A\033[0J"
+            + "message\n"
+            + "\033[1mfooter\033[0m"
+            + "\033[1A\033[0J"
+            + "another message\n"
+            + "\033[1mfooter\033[0m",
+        logBuilder.toString());
+  }
+
+  @Test
+  public void testLog_changingFooter()
+      throws InterruptedException, ExecutionException, TimeoutException {
+    testAnsiLoggerWithFooter
+        .setFooter(Collections.singletonList("footer"))
+        .get(FUTURE_TIMEOUT.getSeconds(), TimeUnit.SECONDS);
+    testAnsiLoggerWithFooter
+        .log(() -> logBuilder.append("message\n"))
+        .get(FUTURE_TIMEOUT.getSeconds(), TimeUnit.SECONDS);
+    testAnsiLoggerWithFooter
+        .setFooter(Arrays.asList("two line", "footer"))
+        .get(FUTURE_TIMEOUT.getSeconds(), TimeUnit.SECONDS);
+    testAnsiLoggerWithFooter
+        .log(() -> logBuilder.append("another message\n"))
+        .get(FUTURE_TIMEOUT.getSeconds(), TimeUnit.SECONDS);
+
+    Assert.assertEquals(
+        "\033[0J"
+            + "\033[1mfooter\033[0m"
+            + "\033[1A\033[0J"
+            + "message\n"
+            + "\033[1mfooter\033[0m"
+            + "\033[1A\033[0J"
+            + "\033[1mtwo line\033[0m\n"
+            + "\033[1mfooter\033[0m"
+            + "\033[1A\033[1A\033[0J"
+            + "another message\n"
+            + "\033[1mtwo line\033[0m\n"
+            + "\033[1mfooter\033[0m",
+        logBuilder.toString());
+  }
+}