Support to list child projects recursively via REST

Change-Id: I046e4d546ca1f0a971382816de4ea76aef035f3f
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>

Documentation/rest-api-projects.txt

@@ -535,6 +535,63 @@ returned that describe the child projects.
   ]
 ----
 
+To resolve the child projects of a project recursively the parameter
+`recursive` can be set.
+
+Child projects that are not visible to the calling user are ignored and
+are not resolved further.
+
+.Request
+----
+  GET /projects/Public-Projects/children/?recursive HTTP/1.0
+----
+
+.Response
+----
+  HTTP/1.1 200 OK
+  Content-Disposition: attachment
+  Content-Type: application/json;charset=UTF-8
+
+  )]}'
+  [
+    {
+      "kind": "gerritcodereview#project",
+      "id": "gerrit",
+      "name": "gerrit",
+      "parent": "Public-Projects",
+      "description": "Gerrit Code Review"
+    },
+    {
+      "kind": "gerritcodereview#project",
+      "id": "plugins%2Freplication",
+      "name": "plugins/replication",
+      "parent": "Public-Plugins",
+      "description": "Copies to other servers using the Git protocol"
+    },
+    {
+      "kind": "gerritcodereview#project",
+      "id": "plugins%2Freviewnotes",
+      "name": "plugins/reviewnotes",
+      "parent": "Public-Plugins",
+      "description": "Annotates merged commits using notes on refs/notes/review."
+    },
+    {
+      "kind": "gerritcodereview#project",
+      "id": "plugins%2Fsingleusergroup",
+      "name": "plugins/singleusergroup",
+      "parent": "Public-Plugins",
+      "description": "GroupBackend enabling users to be directly added to access rules"
+    },
+    {
+      "kind": "gerritcodereview#project",
+      "id": "Public-Plugins",
+      "name": "Public-Plugins",
+      "parent": "Public-Projects",
+      "description": "Parent project for plugins/*"
+    }
+  ]
+----
+
 [[get-child-project]]
 Get Child Project
 ~~~~~~~~~~~~~~~~~

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/rest/project/ListChildProjectsIT.java

@@ -93,6 +93,29 @@ public class ListChildProjectsIT extends AbstractDaemonTest {
     assertProjects(Arrays.asList(child1, child2), children);
   }
 
+  @Test
+  public void listChildrenRecursively() throws IOException, JSchException {
+    SshSession sshSession = new SshSession(admin);
+    Project.NameKey child1 = new Project.NameKey("p1");
+    createProject(sshSession, child1.get());
+    createProject(sshSession, "p2");
+    Project.NameKey child1_1 = new Project.NameKey("p1.1");
+    createProject(sshSession, child1_1.get(), child1);
+    Project.NameKey child1_2 = new Project.NameKey("p1.2");
+    createProject(sshSession, child1_2.get(), child1);
+    Project.NameKey child1_1_1 = new Project.NameKey("p1.1.1");
+    createProject(sshSession, child1_1_1.get(), child1_1);
+    Project.NameKey child1_1_1_1 = new Project.NameKey("p1.1.1.1");
+    createProject(sshSession, child1_1_1_1.get(), child1_1_1);
+
+    RestResponse r = GET("/projects/" + child1.get() + "/children/?recursive");
+    assertEquals(HttpStatus.SC_OK, r.getStatusCode());
+    List<ProjectInfo> children =
+        (new Gson()).fromJson(r.getReader(),
+            new TypeToken<List<ProjectInfo>>() {}.getType());
+    assertProjects(Arrays.asList(child1_1, child1_2, child1_1_1, child1_1_1_1), children);
+  }
+
   private RestResponse GET(String endpoint) throws IOException {
     return session.get(endpoint);
   }

gerrit-server/src/main/java/com/google/gerrit/server/project/ListChildProjects.java

@@ -15,30 +15,49 @@
 package com.google.gerrit.server.project;
 
 import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
 import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.reviewdb.client.Project;
+import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.config.AllProjectsName;
 import com.google.gerrit.server.project.ProjectJson.ProjectInfo;
 import com.google.inject.Inject;
 
+import org.kohsuke.args4j.Option;
+
 import java.util.List;
+import java.util.Map;
 
 public class ListChildProjects implements RestReadView<ProjectResource> {
 
+  @Option(name = "--recursive", usage = "to list child projects recursively")
+  private boolean recursive;
+
   private final ProjectCache projectCache;
   private final AllProjectsName allProjects;
   private final ProjectJson json;
+  private final ProjectNode.Factory projectNodeFactory;
 
   @Inject
   ListChildProjects(ProjectCache projectCache, AllProjectsName allProjects,
-      ProjectJson json) {
+      ProjectJson json, ProjectNode.Factory projectNodeFactory) {
     this.projectCache = projectCache;
     this.allProjects = allProjects;
     this.json = json;
+    this.projectNodeFactory = projectNodeFactory;
   }
 
   @Override
   public List<ProjectInfo> apply(ProjectResource rsrc) {
+    if (recursive) {
+      return getChildProjectsRecursively(rsrc.getNameKey(),
+          rsrc.getControl().getCurrentUser());
+    } else {
+      return getDirectChildProjects(rsrc.getNameKey());
+    }
+  }
+
+  private List<ProjectInfo> getDirectChildProjects(Project.NameKey parent) {
     List<ProjectInfo> childProjects = Lists.newArrayList();
     for (Project.NameKey projectName : projectCache.all()) {
       ProjectState e = projectCache.get(projectName);
@@ -46,10 +65,42 @@ public class ListChildProjects implements RestReadView<ProjectResource> {
         // If we can't get it from the cache, pretend it's not present.
         continue;
       }
-      if (rsrc.getNameKey().equals(e.getProject().getParent(allProjects))) {
+      if (parent.equals(e.getProject().getParent(allProjects))) {
         childProjects.add(json.format(e.getProject()));
       }
     }
     return childProjects;
   }
+
+  private List<ProjectInfo> getChildProjectsRecursively(Project.NameKey parent,
+      CurrentUser user) {
+    Map<Project.NameKey, ProjectNode> projects = Maps.newHashMap();
+    for (Project.NameKey name : projectCache.all()) {
+      ProjectState p = projectCache.get(name);
+      if (p == null) {
+        // If we can't get it from the cache, pretend it's not present.
+        continue;
+      }
+      projects.put(name, projectNodeFactory.create(p.getProject(),
+          p.controlFor(user).isVisible()));
+    }
+    for (ProjectNode key : projects.values()) {
+      ProjectNode node = projects.get(key.getParentName());
+      if (node != null) {
+        node.addChild(key);
+      }
+    }
+    return getChildProjectsRecursively(projects.get(parent));
+  }
+
+  private List<ProjectInfo> getChildProjectsRecursively(ProjectNode p) {
+    List<ProjectInfo> allChildren = Lists.newArrayList();
+    for (ProjectNode c : p.getChildren()) {
+      if (c.isVisible()) {
+        allChildren.add(json.format(c.getProject()));
+        allChildren.addAll(getChildProjectsRecursively(c));
+      }
+    }
+    return allChildren;
+  }
 }

gerrit-server/src/main/java/com/google/gerrit/server/project/ProjectNode.java

@@ -57,6 +57,10 @@ public class ProjectNode implements TreeNode, Comparable<ProjectNode> {
     return allProjectsName.equals(project.getNameKey());
   }
 
+  public Project getProject() {
+    return project;
+  }
+
   @Override
   public String getDisplayName() {
     return project.getName();
@@ -68,7 +72,7 @@ public class ProjectNode implements TreeNode, Comparable<ProjectNode> {
   }
 
   @Override
-  public SortedSet<? extends TreeNode> getChildren() {
+  public SortedSet<? extends ProjectNode> getChildren() {
     return children;
   }