examples/*: rewrite to use future chaining

camallo · Oct 24, 2018 · 64255ef · 64255ef
1 parent d1bdb2a
commit 64255ef
Showing 1 changed file with 50 additions and 30 deletions.
diff --git a/examples/tags.rs b/examples/tags.rs
@@ -2,7 +2,7 @@ extern crate dkregistry;
 extern crate futures;
 extern crate tokio_core;
 
-use futures::stream::Stream;
+use futures::prelude::*;
 use std::{boxed, error};
 use tokio_core::reactor::Core;
 
@@ -38,36 +38,56 @@ fn main() {
 }
 
 fn run(host: &str, user: Option<String>, passwd: Option<String>, image: &str) -> Result<()> {
-    let mut tcore = try!(Core::new());
-    let mut dclient = try!(
-        dkregistry::v2::Client::configure(&tcore.handle())
-            .registry(host)
-            .insecure_registry(false)
-            .username(user)
-            .password(passwd)
-            .build()
-    );
+    let mut tcore = Core::new()?;
+    let client = dkregistry::v2::Client::configure(&tcore.handle())
+        .registry(host)
+        .insecure_registry(false)
+        .username(user)
+        .password(passwd)
+        .build()?;
 
-    let futcheck = dclient.is_v2_supported();
-    let supported = try!(tcore.run(futcheck));
-    if !supported {
-        return Err("API v2 not supported".into());
-    }
-
-    let fut_token = dclient.login(&[&format!("repository:{}:pull", image)]);
-    let token_auth = try!(tcore.run(fut_token));
+    let futures = futures::future::ok::<_, dkregistry::errors::Error>(client)
+        .and_then(|dclient| {
+            dclient.is_v2_supported().and_then(|v2_supported| {
+                if !v2_supported {
+                    Err("API v2 not supported".into())
+                } else {
+                    Ok(dclient)
+                }
+            })
+        }).and_then(|dclient| {
+            dclient.is_auth(None).and_then(|is_auth| {
+                if is_auth {
+                    Err("no login performed, but already authenticated".into())
+                } else {
+                    Ok(dclient)
+                }
+            })
+        }).and_then(|dclient| {
+            dclient.login(&[]).and_then(|token| {
+                dclient
+                    .is_auth(Some(token.token()))
+                    .and_then(move |is_auth| {
+                        if !is_auth {
+                            Err("login failed".into())
+                        } else {
+                            println!("logged in!");
+                            Ok(dclient
+                                .clone()
+                                .set_token(Some(token.token()))
+                                .get_tags(&image, Some(7))
+                                .collect())
+                        }
+                    })
+            })
+        }).and_then(|tags_collect| tags_collect);
 
-    let futauth = dclient.is_auth(Some(token_auth.token()));
-    if !try!(tcore.run(futauth)) {
-        return Err("login failed".into());
+    match tcore.run(futures) {
+        Ok(tags) => {
+            println!("{:?}", tags);
+            Ok(())
+        }
+        Err(e) => Err(Box::new(e)),
+        _ => Err("Login unsucessful".into()),
     }
-
-    dclient.set_token(Some(token_auth.token()));
-
-    let fut_tags = dclient.get_tags(image, Some(7));
-    let tags = tcore.run(fut_tags.collect());
-
-    println!("{:?}", tags);
-
-    return Ok(());
 }