From d23dc6f6af0515ccf2e0696c95c2ff2a414f72cd Mon Sep 17 00:00:00 2001
From: Nikolay Kim <fafhrd91@gmail.com>
Date: Thu, 14 Mar 2019 20:09:34 -0700
Subject: [PATCH] Allow to run future before server service initialization

---
 actix-server/CHANGES.md                       |  7 ++++
 actix-server/src/builder.rs                   |  2 +-
 .../src/{service_config.rs => config.rs}      | 36 +++++++++++++++++--
 actix-server/src/lib.rs                       |  4 +--
 4 files changed, 43 insertions(+), 6 deletions(-)
 rename actix-server/src/{service_config.rs => config.rs} (84%)

diff --git a/actix-server/CHANGES.md b/actix-server/CHANGES.md
index 92a9a31f..968d905e 100644
--- a/actix-server/CHANGES.md
+++ b/actix-server/CHANGES.md
@@ -1,5 +1,12 @@
 # Changes
 
+## [0.4.1] - 2019-03-13
+
+### Added
+
+* Allow to run future before server service initialization
+
+
 ## [0.4.0] - 2019-03-12
 
 ### Changed
diff --git a/actix-server/src/builder.rs b/actix-server/src/builder.rs
index 99f2754f..aac8064a 100644
--- a/actix-server/src/builder.rs
+++ b/actix-server/src/builder.rs
@@ -12,8 +12,8 @@ use num_cpus;
 use tokio_timer::sleep;
 
 use crate::accept::{AcceptLoop, AcceptNotify, Command};
+use crate::config::{ConfiguredService, ServiceConfig};
 use crate::server::{Server, ServerCommand};
-use crate::service_config::{ConfiguredService, ServiceConfig};
 use crate::services::{InternalServiceFactory, ServiceFactory, StreamNewService};
 use crate::signals::{Signal, Signals};
 use crate::worker::{self, Worker, WorkerAvailability, WorkerClient};
diff --git a/actix-server/src/service_config.rs b/actix-server/src/config.rs
similarity index 84%
rename from actix-server/src/service_config.rs
rename to actix-server/src/config.rs
index 20e7adc6..8f360e14 100644
--- a/actix-server/src/service_config.rs
+++ b/actix-server/src/config.rs
@@ -121,9 +121,25 @@ impl InternalServiceFactory for ConfiguredService {
             fut.push(ns.new_service(&config).map(move |service| (token, service)));
         }
 
-        Box::new(join_all(fut).map_err(|e| {
-            error!("Can not construct service: {:?}", e);
-        }))
+        // on start futures
+        if rt.onstart.is_empty() {
+            Box::new(join_all(fut).map_err(|e| {
+                error!("Can not construct service: {:?}", e);
+            }))
+        } else {
+            // run onstart future and then construct services
+            Box::new(
+                join_all(rt.onstart)
+                    .map_err(|e| {
+                        error!("Can not construct service: {:?}", e);
+                    })
+                    .and_then(move |_| {
+                        join_all(fut).map_err(|e| {
+                            error!("Can not construct service: {:?}", e);
+                        })
+                    }),
+            )
+        }
     }
 }
 
@@ -153,6 +169,7 @@ fn not_configured(_: &mut ServiceRuntime) {
 pub struct ServiceRuntime {
     names: HashMap<String, Token>,
     services: HashMap<Token, BoxedNewService>,
+    onstart: Vec<Box<Future<Item = (), Error = ()>>>,
 }
 
 impl ServiceRuntime {
@@ -160,6 +177,7 @@ impl ServiceRuntime {
         ServiceRuntime {
             names,
             services: HashMap::new(),
+            onstart: Vec::new(),
         }
     }
 
@@ -171,6 +189,10 @@ impl ServiceRuntime {
         }
     }
 
+    /// Register service.
+    ///
+    /// Name of the service must be registered during configuration stage with
+    /// *ServiceConfig::bind()* or *ServiceConfig::listen()* methods.
     pub fn service<T, F>(&mut self, name: &str, service: F)
     where
         F: IntoNewService<T, ServerConfig>,
@@ -191,6 +213,14 @@ impl ServiceRuntime {
             panic!("Unknown service: {:?}", name);
         }
     }
+
+    /// Execute future before services initialization.
+    pub fn spawn<F>(&mut self, fut: F)
+    where
+        F: Future<Item = (), Error = ()> + 'static,
+    {
+        self.onstart.push(Box::new(fut))
+    }
 }
 
 type BoxedNewService = Box<
diff --git a/actix-server/src/lib.rs b/actix-server/src/lib.rs
index 2b0beb49..f9eb5721 100644
--- a/actix-server/src/lib.rs
+++ b/actix-server/src/lib.rs
@@ -2,9 +2,9 @@
 
 mod accept;
 mod builder;
+mod config;
 mod counter;
 mod server;
-mod service_config;
 mod services;
 mod signals;
 pub mod ssl;
@@ -13,8 +13,8 @@ mod worker;
 pub use actix_server_config::{Io, Protocol, ServerConfig};
 
 pub use self::builder::ServerBuilder;
+pub use self::config::{ServiceConfig, ServiceRuntime};
 pub use self::server::Server;
-pub use self::service_config::{ServiceConfig, ServiceRuntime};
 pub use self::services::ServiceFactory;
 
 #[doc(hidden)]