Add cache warm-up utility

New SSH command to trigger the warm-up of Gerrit caches.
First cache implemented is project lists and entries.

Change-Id: I1972191a55a7bb03ee338cf8db96e40808f82736

admin/README.md

diff --git a/admin/README.md b/admin/README.md
index 8674119..d59d3eb 100644
--- a/admin/README.md
+++ b/admin/README.md
@@ -8,3 +8,4 @@
 Index
 -----
 [reindexer-1.0.groovy](/admin/reindexer-1.0.groovy) - Allows to recreate the Lucene index using the on-line reindex
+[warm-cache-1.0.groovy](/admin/warm-cache-1.0.groovy) - Controls the Gerrit cache warm-up via command-line

admin/warm-cache-1.0.groovy

diff --git a/admin/warm-cache-1.0.groovy b/admin/warm-cache-1.0.groovy
new file mode 100644
index 0000000..e3eb87c
--- /dev/null
+++ b/admin/warm-cache-1.0.groovy
@@ -0,0 +1,49 @@
+// Copyright (C) 2016 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.
+
+import com.google.gerrit.sshd.*
+import com.google.gerrit.extensions.annotations.*
+import com.google.gerrit.server.project.*
+import com.google.inject.*
+import org.kohsuke.args4j.*
+
+@Export("projects")
+class WarmProjectsCache extends SshCommand {
+
+  @Inject
+  ProjectCache cache
+
+  public void run() {
+    stdout.println "Loading project list ..."
+    def start = System.currentTimeMillis()
+    stdout.flush()
+    def allProjects = cache.all()
+    def totProjects = allProjects.size()
+    def loaded = 0
+
+    for ( project in allProjects ) {
+      cache.get(project.get())
+      loaded++
+      if (loaded%1000==0) {
+        stdout.println "$loaded of $totProjects projects"
+        stdout.flush()
+      }
+    }
+
+    def elapsed = (System.currentTimeMillis()-start)/1000
+
+    stdout.println "$loaded projects loaded in $elapsed secs"
+  }
+}
+