Update to modern KV Store API.

Author: kpfleming

Diff for: src/main.rs

@@ -1,4 +1,5 @@
 use fastly::KVStore;
+use fastly::kv_store::KVStoreError;
 use fastly::{Error, Request, Response};
 
 #[fastly::main]
@@ -10,21 +11,21 @@ fn main(req: Request) -> Result<Response, Error> {
     }
 
     /*
-        Construct an KVStore instance which is connected to the KV Store named `my-store`
+        Construct a KVStore instance which is connected to the KV Store named `my-store`
 
         [Documentation for the KVStore open method can be found here](https://docs.rs/fastly/latest/fastly/struct.KVStore.html#method.open)
     */
-    let mut store = KVStore::open("my-store").map(|store| store.expect("KVStore exists"))?;
+    let store = KVStore::open("my-store").map(|store| store.expect("KVStore exists"))?;
 
     let path = req.get_path();
     if path == "/readme" {
-        let entry = store.lookup("readme")?;
+        let mut lookup = match store.lookup("readme") {
+	    Ok(l) => l,
+	    Err(KVStoreError::ItemNotFound) => return Ok(Response::from_body("Not Found").with_status(404)),
+	    Err(_e) => return Ok(Response::from_body("Lookup Error").with_status(503)),
+	};
 
-        return match entry {
-            // Stream the value back to the user-agent.
-            Some(entry) => Ok(Response::from_body(entry)),
-            None => Ok(Response::from_body("Not Found").with_status(404)),
-        };
+	return Ok(Response::from_body(lookup.take_body()));
     } else {
         /*
         Adds or updates the key `hello` in the KV Store with the value `world`.
@@ -44,12 +45,12 @@ fn main(req: Request) -> Result<Response, Error> {
 
         [Documentation for the lookup method can be found here](https://docs.rs/fastly/latest/fastly/struct.KVStore.html#method.lookup)
         */
-        let entry = store.lookup("hello")?;
+        let mut lookup = match store.lookup("hello") {
+	    Ok(l) => l,
+	    Err(KVStoreError::ItemNotFound) => return Ok(Response::from_body("Not Found").with_status(404)),
+	    Err(_e) => return Ok(Response::from_body("Lookup Error").with_status(503)),
+	};
 
-        return match entry {
-            // Stream the value back to the user-agent.
-            Some(entry) => Ok(Response::from_body(entry)),
-            None => Ok(Response::from_body("Not Found").with_status(404)),
-        };
+	return Ok(Response::from_body(lookup.take_body()));
     }
 }