Support paging in Resource Manager

gcloud-java-resourcemanager/src/main/java/com/google/gcloud/resourcemanager/ResourceManager.java

@@ -147,8 +147,6 @@ public static ProjectListOption pageToken(String pageToken) {
      *
      * <p>The server can return fewer projects than requested. When there are more results than the
      * page size, the server will return a page token that can be used to fetch other results.
-     * Note: pagination is not yet supported; the server currently ignores this field and returns
-     * all results.
      */
     public static ProjectListOption pageSize(int pageSize) {
       return new ProjectListOption(ResourceManagerRpc.Option.PAGE_SIZE, pageSize);
@@ -228,8 +226,7 @@ public static ProjectListOption fields(ProjectField... fields) {
    *
    * <p>This method returns projects in an unspecified order. New projects do not necessarily appear
    * at the end of the list. Use {@link ProjectListOption} to filter this list, set page size, and
-   * set page tokens. Note that pagination is currently not implemented by the Cloud Resource
-   * Manager API.
+   * set page tokens.
    *
    * @see <a
    * href="https://cloud.google.com/resource-manager/reference/rest/v1beta1/projects/list">Cloud

gcloud-java-resourcemanager/src/main/java/com/google/gcloud/resourcemanager/testing/LocalResourceManagerHelper.java

@@ -34,7 +34,7 @@
 import java.util.Map;
 import java.util.Random;
 import java.util.Set;
-import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentSkipListMap;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import java.util.zip.GZIPInputStream;
@@ -71,7 +71,7 @@ public class LocalResourceManagerHelper {
       ImmutableSet.of('-', '\'', '"', ' ', '!');
 
   private final HttpServer server;
-  private final ConcurrentHashMap<String, Project> projects = new ConcurrentHashMap<>();
+  private final ConcurrentSkipListMap<String, Project> projects = new ConcurrentSkipListMap<>();
   private final int port;
 
   private static class Response {
@@ -228,7 +228,7 @@ private static String[] parseFields(String query) {
     return null;
   }
 
-  private static Map<String, Object> parseListOptions(String query) {
+  private static Map<String, Object> parseListOptions(String query) throws IOException {
     Map<String, Object> options = new HashMap<>();
     if (query != null) {
       String[] args = query.split("&");
@@ -245,10 +245,14 @@ private static Map<String, Object> parseListOptions(String query) {
             options.put("filter", argEntry[1].split(" "));
             break;
           case "pageToken":
-            // support pageToken when Cloud Resource Manager supports this (#421)
+            options.put("pageToken", argEntry[1]);
             break;
           case "pageSize":
-            // support pageSize when Cloud Resource Manager supports this (#421)
+            int pageSize = Integer.valueOf(argEntry[1]);
+            if (pageSize < 1) {
+              throw new IOException("Page size must be greater than 0.");
+            }
+            options.put("pageSize", pageSize);
             break;
         }
       }
@@ -353,16 +357,28 @@ Response get(String projectId, String[] fields) {
   }
 
   Response list(Map<String, Object> options) {
-    // Use pageSize and pageToken options when Cloud Resource Manager does so (#421)
     List<String> projectsSerialized = new ArrayList<>();
     String[] filters = (String[]) options.get("filter");
     if (filters != null && !isValidFilter(filters)) {
       return Error.INVALID_ARGUMENT.response("Could not parse the filter.");
     }
     String[] fields = (String[]) options.get("fields");
-    for (Project p : projects.values()) {
+    int count = 0;
+    String pageToken = (String) options.get("pageToken");
+    Integer pageSize = (Integer) options.get("pageSize");
+    String nextPageToken = null;
+    Map<String, Project> projectsToScan = projects;
+    if (pageToken != null) {
+      projectsToScan = projects.tailMap(pageToken);
+    }
+    for (Project p : projectsToScan.values()) {
+      if (pageSize != null && count >= pageSize) {
+        nextPageToken = p.getProjectId();
+        break;
+      }
       boolean includeProject = includeProject(p, filters);
       if (includeProject) {
+        count++;
         try {
           projectsSerialized.add(jsonFactory.toString(extractFields(p, fields)));
         } catch (IOException e) {
@@ -374,7 +390,13 @@ Response list(Map<String, Object> options) {
     StringBuilder responseBody = new StringBuilder();
     responseBody.append("{\"projects\": [");
     Joiner.on(",").appendTo(responseBody, projectsSerialized);
-    responseBody.append("]}");
+    responseBody.append(']');
+    if (nextPageToken != null) {
+      responseBody.append(", \"nextPageToken\": \"");
+      responseBody.append(nextPageToken);
+      responseBody.append('"');
+    }
+    responseBody.append('}');
     return new Response(HTTP_OK, responseBody.toString());
   }
 

gcloud-java-resourcemanager/src/test/java/com/google/gcloud/resourcemanager/LocalResourceManagerHelperTest.java

@@ -19,6 +19,7 @@
 import org.junit.Test;
 
 import java.util.HashMap;
+import java.util.Iterator;
 import java.util.Map;
 
 public class LocalResourceManagerHelperTest {
@@ -278,7 +279,7 @@ public void testGetWithOptions() {
   public void testList() {
     Tuple<String, Iterable<com.google.api.services.cloudresourcemanager.model.Project>> projects =
         rpc.list(EMPTY_RPC_OPTIONS);
-    assertNull(projects.x()); // change this when #421 is resolved
+    assertNull(projects.x());
     assertFalse(projects.y().iterator().hasNext());
     rpc.create(COMPLETE_PROJECT);
     RESOURCE_MANAGER_HELPER.changeLifecycleState(
@@ -296,12 +297,43 @@ public void testList() {
     }
   }
 
+  @Test
+  public void testInvalidListPaging() {
+    Map<ResourceManagerRpc.Option, Object> rpcOptions = new HashMap<>();
+    rpcOptions.put(ResourceManagerRpc.Option.PAGE_SIZE, -1);
+    try {
+      rpc.list(rpcOptions);
+    } catch (ResourceManagerException e) {
+      assertEquals("Page size must be greater than 0.", e.getMessage());
+    }
+  }
+
+  @Test
+  public void testListPaging() {
+    Map<ResourceManagerRpc.Option, Object> rpcOptions = new HashMap<>();
+    rpcOptions.put(ResourceManagerRpc.Option.PAGE_SIZE, 1);
+    rpc.create(PARTIAL_PROJECT);
+    rpc.create(COMPLETE_PROJECT);
+    Tuple<String, Iterable<com.google.api.services.cloudresourcemanager.model.Project>> projects =
+        rpc.list(rpcOptions);
+    assertNotNull(projects.x());
+    Iterator<com.google.api.services.cloudresourcemanager.model.Project> iterator =
+        projects.y().iterator();
+    compareReadWriteFields(COMPLETE_PROJECT, iterator.next());
+    assertFalse(iterator.hasNext());
+    rpcOptions = new HashMap<>();
+    rpcOptions.put(ResourceManagerRpc.Option.PAGE_TOKEN, projects.x());
+    projects = rpc.list(rpcOptions);
+    iterator = projects.y().iterator();
+    compareReadWriteFields(PARTIAL_PROJECT, iterator.next());
+    assertFalse(iterator.hasNext());
+    assertNull(projects.x());
+  }
+
   @Test
   public void testListFieldOptions() {
     Map<ResourceManagerRpc.Option, Object> rpcOptions = new HashMap<>();
     rpcOptions.put(ResourceManagerRpc.Option.FIELDS, "projects(projectId,name,labels)");
-    rpcOptions.put(ResourceManagerRpc.Option.PAGE_TOKEN, "somePageToken");
-    rpcOptions.put(ResourceManagerRpc.Option.PAGE_SIZE, 1);
     rpc.create(PROJECT_WITH_PARENT);
     Tuple<String, Iterable<com.google.api.services.cloudresourcemanager.model.Project>> projects =
         rpc.list(rpcOptions);

gcloud-java-resourcemanager/src/test/java/com/google/gcloud/resourcemanager/ResourceManagerImplTest.java

@@ -42,6 +42,7 @@
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
+import java.util.Iterator;
 import java.util.Map;
 
 public class ResourceManagerImplTest {
@@ -166,7 +167,7 @@ public void testGetWithOptions() {
   @Test
   public void testList() {
     Page<Project> projects = RESOURCE_MANAGER.list();
-    assertFalse(projects.values().iterator().hasNext()); // TODO: change this when #421 is resolved
+    assertFalse(projects.values().iterator().hasNext());
     RESOURCE_MANAGER.create(PARTIAL_PROJECT);
     RESOURCE_MANAGER.create(COMPLETE_PROJECT);
     for (Project p : RESOURCE_MANAGER.list().values()) {
@@ -181,6 +182,22 @@ public void testList() {
     }
   }
 
+  @Test
+  public void testListPaging() {
+    RESOURCE_MANAGER.create(PARTIAL_PROJECT);
+    RESOURCE_MANAGER.create(COMPLETE_PROJECT);
+    Page<Project> page = RESOURCE_MANAGER.list(ProjectListOption.pageSize(1));
+    assertNotNull(page.nextPageCursor());
+    Iterator<Project> iterator = page.values().iterator();
+    compareReadWriteFields(COMPLETE_PROJECT, iterator.next());
+    assertFalse(iterator.hasNext());
+    page = page.nextPage();
+    iterator = page.values().iterator();
+    compareReadWriteFields(PARTIAL_PROJECT, iterator.next());
+    assertFalse(iterator.hasNext());
+    assertNull(page.nextPageCursor());
+  }
+
   @Test
   public void testListFieldOptions() {
     RESOURCE_MANAGER.create(COMPLETE_PROJECT);