Project index: Add parent predicate

Enabling the search by parent enables the rewrite
of the ListChildProjects REST-API that extracts the children
of a project. Using the Lucene index avoids the full scan
of the ProjectCache and thus speedup the extraction and
reduce the JVM heap consumption.

Bug: Issue 10401
Change-Id: I568d6ba0e5a0bff391f57e2357de6d059d77fe5d

Documentation/user-search-projects.txt

@@ -12,6 +12,11 @@ name:'NAME'::
 +
 Matches projects that have exactly the name 'NAME'.
 
+[[parent]]
+parent:'PARENT'::
++
+Matches projects that have 'PARENT' as parent project.
+
 [[inname]]
 inname:'NAME'::
 +

java/com/google/gerrit/server/query/project/ProjectPredicates.java

@@ -27,6 +27,10 @@ public class ProjectPredicates {
     return new ProjectPredicate(ProjectField.NAME, nameKey.get());
   }
 
+  public static Predicate<ProjectData> parent(Project.NameKey parentNameKey) {
+    return new ProjectPredicate(ProjectField.PARENT_NAME, parentNameKey.get());
+  }
+
   public static Predicate<ProjectData> inname(String name) {
     return new ProjectPredicate(ProjectField.NAME_PART, name.toLowerCase(Locale.US));
   }

java/com/google/gerrit/server/query/project/ProjectQueryBuilder.java

@@ -44,6 +44,11 @@ public class ProjectQueryBuilder extends QueryBuilder<ProjectData> {
     return ProjectPredicates.name(new Project.NameKey(name));
   }
 
+  @Operator
+  public Predicate<ProjectData> parent(String parentName) {
+    return ProjectPredicates.parent(new Project.NameKey(parentName));
+  }
+
   @Operator
   public Predicate<ProjectData> inname(String namePart) {
     if (namePart.isEmpty()) {

javatests/com/google/gerrit/server/query/project/AbstractQueryProjectsTest.java

@@ -20,6 +20,7 @@ import static java.util.stream.Collectors.toList;
 
 import com.google.common.base.CharMatcher;
 import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
 import com.google.gerrit.extensions.api.GerritApi;
 import com.google.gerrit.extensions.api.access.AccessSectionInfo;
 import com.google.gerrit.extensions.api.access.PermissionInfo;
@@ -49,6 +50,7 @@ import com.google.gerrit.server.account.Accounts;
 import com.google.gerrit.server.account.AccountsUpdate;
 import com.google.gerrit.server.account.AuthRequest;
 import com.google.gerrit.server.config.AllProjectsName;
+import com.google.gerrit.server.config.AllUsersName;
 import com.google.gerrit.server.group.SystemGroupBackend;
 import com.google.gerrit.server.schema.SchemaCreator;
 import com.google.gerrit.server.util.ManualRequestContext;
@@ -65,6 +67,7 @@ import java.util.Arrays;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Locale;
+import java.util.Set;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Ignore;
@@ -98,6 +101,8 @@ public abstract class AbstractQueryProjectsTest extends GerritServerTests {
 
   @Inject protected AllProjectsName allProjects;
 
+  @Inject protected AllUsersName allUsers;
+
   protected LifecycleManager lifecycle;
   protected Injector injector;
   protected ReviewDb db;
@@ -192,6 +197,28 @@ public abstract class AbstractQueryProjectsTest extends GerritServerTests {
     assertQuery("name:" + projectWithHyphen.name, projectWithHyphen);
   }
 
+  @Test
+  public void byParent() throws Exception {
+    assertQuery("parent:project");
+    ProjectInfo parent = createProject(name("parent"));
+    assertQuery("parent:" + parent.name);
+    ProjectInfo child = createProject(name("child"), parent.name);
+    assertQuery("parent:" + parent.name, child);
+  }
+
+  @Test
+  public void byParentOfAllProjects() throws Exception {
+    Set<String> excludedProjects = ImmutableSet.of(allProjects.get(), allUsers.get());
+    ProjectInfo[] projects =
+        gApi.projects()
+            .list()
+            .get()
+            .stream()
+            .filter(p -> !excludedProjects.contains(p.name))
+            .toArray(s -> new ProjectInfo[s]);
+    assertQuery("parent:" + allProjects.get(), projects);
+  }
+
   @Test
   public void byInname() throws Exception {
     String namePart = getSanitizedMethodName();
@@ -329,6 +356,13 @@ public abstract class AbstractQueryProjectsTest extends GerritServerTests {
     return gApi.projects().create(in).get();
   }
 
+  protected ProjectInfo createProject(String name, String parent) throws Exception {
+    ProjectInput in = new ProjectInput();
+    in.name = name;
+    in.parent = parent;
+    return gApi.projects().create(in).get();
+  }
+
   protected ProjectInfo createProjectWithDescription(String name, String description)
       throws Exception {
     ProjectInput in = new ProjectInput();