Merge pull request facebook#3 from pikiwidb/feature/user_define_uploa…

…d_function

add parameter to specify user defined cloudmanifest upload function

cloud/cloud_file_system_impl.cc

@@ -2077,6 +2077,18 @@ IOStatus CloudFileSystemImpl::UploadCloudManifest(
   if (!cloud_fs_options.is_master) {
     return IOStatus::OK();
   }
+
+  if (cloud_fs_options.upload_meta_func) {
+    bool success = cloud_fs_options.upload_meta_func(MakeCloudManifestFile(local_dbname, cookie),
+        GetDestBucketName(), MakeCloudManifestFile(GetDestObjectPath(), cookie));
+    if (!success) {
+      Log(InfoLogLevel::WARN_LEVEL, info_log_,
+          "[%s] UploadCloudManifest, user-defined upload failed", Name());
+      return IOStatus::IOError("user defined upload failed");
+    }
+    return IOStatus::OK();
+  }
+
   // upload the cloud manifest file corresponds to cookie (i.e.,
   // CLOUDMANIFEST-cookie)
   auto st = GetStorageProvider()->PutCloudObject(

include/rocksdb/cloud/cloud_file_system.h

@@ -301,6 +301,12 @@ class CloudFileSystemOptions {
   // if rocksdb works in master process
   bool is_master;
 
+  // user defined meta upload function
+  // used to garantee only one server to update remote meta
+  std::function<bool(const std::string& local_path,
+      const std::string& bucket_name,
+      const std::string& object_path)> upload_meta_func;
+
   // Experimental option!
   // This option only affects how resync_on_open works. If resync_on_open is true,
   // and resync_manifest_on_open is true, besides fetching CLOUDMANFIEST from s3,