Split off config REST endpoints from giant server lib

Move Collections and RestViews for config into server/restapi/ They
form a new java_library which uses the server package as a client.

Resources stay put so plugins that handlers for existing resources do
not break.

Change-Id: I724cb3efe160d2f62fa1a67823999abad589e246

java/com/google/gerrit/server/restapi/config/CachesCollection.java

@@ -0,0 +1,102 @@
+// Copyright (C) 2014 The Android Open Source Project
+//
+// 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.gerrit.server.restapi.config;
+
+import static com.google.gerrit.common.data.GlobalCapability.MAINTAIN_SERVER;
+import static com.google.gerrit.common.data.GlobalCapability.VIEW_CACHES;
+
+import com.google.common.cache.Cache;
+import com.google.gerrit.extensions.annotations.RequiresAnyCapability;
+import com.google.gerrit.extensions.registration.DynamicMap;
+import com.google.gerrit.extensions.restapi.AcceptsPost;
+import com.google.gerrit.extensions.restapi.AuthException;
+import com.google.gerrit.extensions.restapi.ChildCollection;
+import com.google.gerrit.extensions.restapi.IdString;
+import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
+import com.google.gerrit.extensions.restapi.RestApiException;
+import com.google.gerrit.extensions.restapi.RestView;
+import com.google.gerrit.server.CurrentUser;
+import com.google.gerrit.server.config.CacheResource;
+import com.google.gerrit.server.config.ConfigResource;
+import com.google.gerrit.server.permissions.GlobalPermission;
+import com.google.gerrit.server.permissions.PermissionBackend;
+import com.google.gerrit.server.permissions.PermissionBackendException;
+import com.google.inject.Inject;
+import com.google.inject.Provider;
+import com.google.inject.Singleton;
+
+@RequiresAnyCapability({VIEW_CACHES, MAINTAIN_SERVER})
+@Singleton
+public class CachesCollection
+    implements ChildCollection<ConfigResource, CacheResource>, AcceptsPost<ConfigResource> {
+
+  private final DynamicMap<RestView<CacheResource>> views;
+  private final Provider<ListCaches> list;
+  private final PermissionBackend permissionBackend;
+  private final Provider<CurrentUser> self;
+  private final DynamicMap<Cache<?, ?>> cacheMap;
+  private final PostCaches postCaches;
+
+  @Inject
+  CachesCollection(
+      DynamicMap<RestView<CacheResource>> views,
+      Provider<ListCaches> list,
+      PermissionBackend permissionBackend,
+      Provider<CurrentUser> self,
+      DynamicMap<Cache<?, ?>> cacheMap,
+      PostCaches postCaches) {
+    this.views = views;
+    this.list = list;
+    this.permissionBackend = permissionBackend;
+    this.self = self;
+    this.cacheMap = cacheMap;
+    this.postCaches = postCaches;
+  }
+
+  @Override
+  public RestView<ConfigResource> list() {
+    return list.get();
+  }
+
+  @Override
+  public CacheResource parse(ConfigResource parent, IdString id)
+      throws AuthException, ResourceNotFoundException, PermissionBackendException {
+    permissionBackend.user(self).check(GlobalPermission.VIEW_CACHES);
+
+    String cacheName = id.get();
+    String pluginName = "gerrit";
+    int i = cacheName.lastIndexOf('-');
+    if (i != -1) {
+      pluginName = cacheName.substring(0, i);
+      cacheName = cacheName.length() > i + 1 ? cacheName.substring(i + 1) : "";
+    }
+
+    Provider<Cache<?, ?>> cacheProvider = cacheMap.byPlugin(pluginName).get(cacheName);
+    if (cacheProvider == null) {
+      throw new ResourceNotFoundException(id);
+    }
+    return new CacheResource(pluginName, cacheName, cacheProvider);
+  }
+
+  @Override
+  public DynamicMap<RestView<CacheResource>> views() {
+    return views;
+  }
+
+  @Override
+  public PostCaches post(ConfigResource parent) throws RestApiException {
+    return postCaches;
+  }
+}