Adds ProgressDisplayGenerator.

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

@@ -0,0 +1,125 @@
+/*
+ * 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.cloud.tools.jib.event.progress.Allocation;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+
+/**
+ * Generates a display of progress and unfinished tasks.
+ *
+ * <p>Example:
+ *
+ * <p>Executing tasks... [================= ] 72.5% complete > task 1 running > task 3 running
+ */
+class ProgressDisplayGenerator {
+
+  /** Line above progress bar. */
+  private static final String HEADER = "Executing tasks:";
+
+  /** Maximum number of bars in the progress display. */
+  private static final int PROGRESS_BAR_COUNT = 50;
+
+  /**
+   * Generates a progress display.
+   *
+   * @param progress the overall progress, with {@code 1.0} meaning fully complete
+   * @param unfinishedAllocations the unfinished {@link Allocation}s
+   * @return the progress display as a list of lines
+   */
+  static List<String> generateProgressDisplay(
+      double progress, List<Allocation> unfinishedAllocations) {
+    List<String> lines = new ArrayList<>();
+
+    lines.add(HEADER);
+    lines.add(generateProgressBar(progress));
+    lines.addAll(generateUnfinishedTasks(unfinishedAllocations));
+
+    return lines;
+  }
+
+  /**
+   * Generates the progress bar line.
+   *
+   * @param progress the overall progress, with {@code 1.0} meaning fully complete
+   * @return the progress bar line
+   */
+  private static String generateProgressBar(double progress) {
+    StringBuilder progressBar = new StringBuilder();
+    progressBar.append('[');
+
+    int barsToDisplay = (int) Math.round(PROGRESS_BAR_COUNT * progress);
+    for (int barIndex = 0; barIndex < PROGRESS_BAR_COUNT; barIndex++) {
+      progressBar.append(barIndex < barsToDisplay ? '=' : ' ');
+    }
+
+    return progressBar
+        .append(']')
+        .append(String.format(" %.1f", progress * 100))
+        .append("% complete")
+        .toString();
+  }
+
+  /**
+   * Generates the display of the unfinished tasks from a list of unfinished {@link Allocation}s
+   *
+   * @param unfinishedAllocations the list of unfinished {@link Allocation}s
+   * @return the display of the unfinished {@link Allocation}s
+   */
+  private static List<String> generateUnfinishedTasks(List<Allocation> unfinishedAllocations) {
+    List<String> lines = new ArrayList<>();
+    for (Allocation unfinishedAllocation : getLeafAllocations(unfinishedAllocations)) {
+      lines.add("> " + unfinishedAllocation.getDescription());
+    }
+    return lines;
+  }
+
+  /**
+   * Gets a list of just the leaf {@link Allocation}s in {@code unfinishedAllocations} in the same
+   * order as they appear in {@code unfinishedAllocations}.
+   *
+   * @param unfinishedAllocations the list of unfinished {@link Allocation}s
+   * @return the list of unfinished {@link Allocation}s
+   */
+  private static List<Allocation> getLeafAllocations(List<Allocation> unfinishedAllocations) {
+    // Prunes the set of all unfinished Allocations to leave just the leaves.
+    Set<Allocation> leafAllocationSet = new HashSet<>(unfinishedAllocations);
+    for (Allocation allocation : unfinishedAllocations) {
+      Optional<Allocation> parent = allocation.getParent();
+
+      while (parent.isPresent()) {
+        leafAllocationSet.remove(parent.get());
+        parent = parent.get().getParent();
+      }
+    }
+
+    // Makes a list of leaf allocations in the same order as the unfinishedAllocations.
+    List<Allocation> leafAllocations = new ArrayList<>();
+    for (Allocation allocation : unfinishedAllocations) {
+      if (leafAllocationSet.contains(allocation)) {
+        leafAllocations.add(allocation);
+      }
+    }
+    return leafAllocations;
+  }
+
+  private ProgressDisplayGenerator() {}
+}

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

@@ -0,0 +1,71 @@
+/*
+ * 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.cloud.tools.jib.event.progress.Allocation;
+import java.util.Arrays;
+import java.util.Collections;
+import org.junit.Assert;
+import org.junit.Test;
+
+/** Tests for {@link ProgressDisplayGenerator}. */
+public class ProgressDisplayGeneratorTest {
+
+  @Test
+  public void testGenerateProgressDisplay_progressBar_0() {
+    Assert.assertEquals(
+        Arrays.asList(
+            "Executing tasks:",
+            "[                                                  ] 0.0% complete"),
+        ProgressDisplayGenerator.generateProgressDisplay(0, Collections.emptyList()));
+  }
+
+  @Test
+  public void testGenerateProgressDisplay_progressBar_50() {
+    Assert.assertEquals(
+        Arrays.asList(
+            "Executing tasks:",
+            "[=========================                         ] 50.0% complete"),
+        ProgressDisplayGenerator.generateProgressDisplay(0.5, Collections.emptyList()));
+  }
+
+  @Test
+  public void testGenerateProgressDisplay_progressBar_100() {
+    Assert.assertEquals(
+        Arrays.asList(
+            "Executing tasks:",
+            "[==================================================] 100.0% complete"),
+        ProgressDisplayGenerator.generateProgressDisplay(1, Collections.emptyList()));
+  }
+
+  @Test
+  public void testGenerateProgressDisplay_unfinishedTasks() {
+    Allocation root = Allocation.newRoot("does not display", 2);
+    Allocation childLeft = root.newChild("does not display", 2);
+    Allocation childLeftDown = childLeft.newChild("childLeftDown", 2);
+    Allocation childRight = root.newChild("childRight", 2);
+
+    Assert.assertEquals(
+        Arrays.asList(
+            "Executing tasks:",
+            "[=========================                         ] 50.0% complete",
+            "> childLeftDown",
+            "> childRight"),
+        ProgressDisplayGenerator.generateProgressDisplay(
+            0.5, Arrays.asList(root, childLeft, childLeftDown, childRight)));
+  }
+}