Merge pull request #16 from zhuangxm/inject-request-parameters

using the idea of the web_func to inject params to function

README.md

@@ -105,6 +105,35 @@ and if we invoke function like (+ 1 3) with token1,
 
 then we will get a correct answer 4.
 
+## inject invoke parameter
+
+Sometime, some parameters that method need (like client-ip) that the
+web client can not get. we can dynamic inject this kind of parameters
+(from ring request) into method.
+
+the export-commands support options like 
+{:params-inject [ [:remote-addr] [:header "host]]}
+
+and clj-rpc will (get-in request [:remote-addr]) and (get-in request
+[:header "host"]) as the first and second parameter of the method that
+client invokes.
+
+Example: 
+```clojure
+(defn fn-do-someting [client-ip username]
+      ... )
+
+(export-commands 'mynamespace ["fn-do-something"]
+                 {:params-inject [ [:remote-addr] ]})
+```
+
+Then the client will invoke function like (fn-do-something usernmae)
+and the clj-rpc will dynamic invoke like (fn-do-something "127.0.0.1"
+username)
+
+Notice: Now, clj-rpc only supprots to inject params into the front of the
+parameters that client supplied .
+
 ## user data
 
 Sometime , we need to access data (like session) related the connection.

project.clj

@@ -1,4 +1,4 @@
-(defproject clj-rpc "0.2.1"
+(defproject clj-rpc "0.2.2-SNAPSHOT"
             :description "simple rpc using clojure"
             :dependencies [[org.clojure/clojure "1.3.0"]
                            [org.clojure/tools.logging "0.2.3"]

src/clj_rpc/context.clj

@@ -2,6 +2,17 @@
   (:require [ring.middleware.cookies :as cookies]
             [clj-rpc.user-data :as data]))
 
+(defn wrap-client-ip
+  "let :remote-addr represents the real client ip even though
+   the client connects through a proxy server"
+  [handler]
+  (fn [request]
+    (let [ip-from-proxy (get-in request [:headers "X-Forwarded-For"])
+          request (if ip-from-proxy
+                    (assoc request :remote-addr ip-from-proxy)
+                    request)]
+      (handler request))))
+
 (defn wrap-context
   "accoding to the token
      (come from cookie in the http request or the token parameters)
@@ -22,52 +33,97 @@
 
 (defn add-context
   "add context to specific command
-   options is a map include several keys
+   options is a collection include several keys
+   like [ [:requre-context true] [:params-checks ...] [... ...] ]
+   
+   the meaning of option:
    :require-context (true or false default false)
       whether this command must have context
    :params-checks
      check parameters of the method be invoked statisfy the sepcific requirements
      example :
        {0 [:username]} -->
-       the first parameter must equals (get-in context [:username])"
+       the first parameter must equals (get-in context [:username])
+   :params-inject
+      inject parameters from request into the function
+      example :
+       [ [:remote-addr] [:server-name] ] -->
+       client-ip and server-name as the first and second parameter of the function
+       if client invoke (fun param1 param2) then the acutally invoke will be like
+       (fun client-ip server-name param1 param2)"
   [command options]
-  (merge command options))
+  (assoc command :options options))
 
 (defn add-context-to-command-map
   "add context options to all the command in the command-map
    options : same as add-context"
   [command-map options]
-  (into {} (map (fn [[k v]] [k (merge v options)]) command-map)))
+  (into {} (map (fn [[k v]] [k (add-context v options)]) command-map)))
+
+(defn error-method-request?
+  "return true if method-reqeust error
+  else false"
+  [method-request]
+  (boolean (:error method-request)))
+
+(defmulti render-method-request
+  "adjust method request by option
+   return new method-request"
+  (fn [option-key option-value request method-request]
+    option-key))
 
-(defn- check-authorization
-  "return nil if the command don't need authrization or
-   the context include the authorization information
-   else return {:code :unauthorized}"
-  [context command]
-  (when (and (get command :require-context)
-             (not (seq context)))
-    {:code :unauthorized}))
+;;render method-request :require-context option
+;;return method-request with error or original method-request
+(defmethod render-method-request :require-context
+  [_ option-value request method-request]
+  (if (and option-value
+             (not (seq (get request :context) )))
+    (assoc method-request :error {:code :unauthorized})
+    method-request))
 
-(defn- check-params
-  "return nil
-      if the params of the command satisfy the requirement of the command
-      provided specific context
-   else return {:code invalid-params :message error-message}"
-  [context command command-params]
-  (letfn [(fn-check [[k v]]
-            (if (not= (nth command-params k) (get-in context v))
+;;render method-request :params-check option
+;;return method-request with params error or original method-request
+(defmethod render-method-request :params-check
+  [_ option-value request method-request]
+  (let [{context :context} request
+        {params :params} method-request
+        fn-check
+        (fn [[k v]]
+            (if (not= (nth params k) (get-in context v))
               {:code :invalid-params
-               :message (str "the " k "th param must be " (get-in context v ))} ))]
-    (->> (:params-checks command)
-         (map fn-check )
-         (filter identity)
-         first)))
+               :message (str "the " k "th param must be "
+                             (get-in context v))}))]
+    (if-let [error (->> option-value
+                (map fn-check )
+                (filter identity)
+                first)]
+      (assoc method-request :error error)
+      method-request)))
+
+;;render method-request :params-inject option
+;;inject the params from request needed by the command
+;;into the actual params
+;;return the new method-request
+(defmethod render-method-request :params-inject
+  [_ option-value request method-request]
+  (if option-value
+    (update-in method-request [:params]
+               #(concat (map (partial get-in request) option-value) %))
+    method-request))
+
+;;default throw RuntimeException
+(defmethod render-method-request :default
+  [option-key option-value request method-request]
+  (throw (RuntimeException. (str "Unknown command option: " option-key
+                                 "method-request: " method-request )  )) )
 
-(defn check-context
-  "check whether the command and params statisfy the requirement
-   if success return nil
-   else return {:code error-code :message error-message}
-   error-code refer to clj-rpc.rpc.clj"
-  [command context params]
-  (or (check-authorization context command)
-      (check-params context command params)))
+(defn adjust-method-request
+  "return new method-request (possible with error message)"
+  [cmd request method-request]
+  (loop [options (:options cmd)
+         m-r method-request]
+    (let [[option-key option-value] (first options)]
+      (if (or (nil? option-key) (error-method-request? m-r))
+        m-r
+        (recur (rest options)
+               (render-method-request option-key option-value request m-r))))))

src/clj_rpc/rpc.clj

@@ -43,10 +43,12 @@
   "execute a function f  with params
    return rpc response
    id : used for generate the response"
-  [f params id]
+  [f {:keys [params id error]}]
   (try
-    (if f 
-      (mk-response (apply f params) id)
-      (mk-error :method-not-found id))
+    (if error
+      (mk-error (:code error) id (:message error))
+      (if f 
+        (mk-response (apply f params) id)
+        (mk-error :method-not-found id)))
     (catch ArityException e (mk-error :invalid-params id (.getMessage e)) )
     (catch Exception e (mk-error :internal-error id (.getMessage e)))))

src/clj_rpc/server.clj

@@ -37,8 +37,11 @@
 (defn export-commands
   "export all functions (fn-names is null or empty)
    or specify functions in the namespace ns
+   invoker of this method must notice the order of the options
+  options:    options is a collection include several keys
+    like [ [:requre-context true] [:params-checks ...] [... ...] ]
 
-  options:  is a map include several keys
+  the meaning of option:
    :require-context (true or false default false)
       whether this command must have context
    :params-checks
@@ -52,7 +55,7 @@
    (export-commands \"clojure.core\" nil)
    (export-commands 'clojure.core ['+])
    (export-commands 'clojure.core [\"+\"]
-                    {:require-context true :params-check {0 [:id]}})"
+                    [ [:require-context true] [:params-check {0 [:id]}] ])"
   [ns fn-names & [options]]
   (let [ns (symbol ns)]
     (require ns)
@@ -66,15 +69,13 @@
   "get the function from the command-map according the method-name and
    execute this function with args
    return the execute result"
-  [command-map context {:keys [method params id]}]
-  (logging/debug "execute-command == method-name: "
-                 method " params: " params " id: " id)
-  (let [cmd (command-map method)
+  [command-map request method-request]
+  (logging/debug "execute-command == " method-request)
+  (let [cmd (command-map (:method method-request))
         f (and cmd (command/.func cmd))
-        check-result (context/check-context cmd context params)]
-    (if check-result
-      (rpc/mk-error (:code check-result) id (:message check-result))
-      (rpc/execute-method f params id))))
+        new-method-request (context/adjust-method-request
+                            cmd request method-request)]
+    (rpc/execute-method f new-method-request)))
 
 (defn help-commands
   "return the command list"
@@ -90,9 +91,9 @@
 (defn rpc-invoke
   "invoke rpc method
    rpc-request can a map (one invoke) or a collection of map (multi invokes)"
-  [command-map context rpc-request]
+  [command-map request rpc-request]
   (letfn [(fn-execute [r]
-             (execute-command command-map context
+             (execute-command command-map request
                               (change-str->keyword r)))]
     (if (map? rpc-request)
       (fn-execute rpc-request)
@@ -102,11 +103,11 @@
   (ANY "/:s-method/help" [s-method]
        (when-let [[f-encode] (protocol/serialization s-method)]
          (f-encode (help-commands @commands))))
-  (POST "/:s-method/invoke" [s-method :as {context :context body :body}]
-        (let [rpc-request (slurp body)]
+  (POST "/:s-method/invoke" [s-method :as reqeust]
+        (let [rpc-request (slurp (:body reqeust))]
           (logging/debug "invoking (" s-method ") request: " rpc-request)
           (let [[f-encode f-decode] (protocol/serialization s-method)]
-            (f-encode (rpc-invoke @commands context (f-decode rpc-request))))))
+            (f-encode (rpc-invoke @commands reqeust (f-decode rpc-request))))))
   (route/not-found "invalid url"))
 
 ;;define a jetty-instance used to start or stop
@@ -120,11 +121,12 @@
   (reset! jetty-instance nil))
 
 (defn build-hander [options]
-  (handler/site
-   (context/wrap-context  main-routes
-                          (:fn-get-context options)
-                          (:cookie-attrs options)
-                          (:token-cookie-key options))))
+  (-> main-routes
+      (context/wrap-context (:fn-get-context options)
+                            (:cookie-attrs options)
+                            (:token-cookie-key options))
+      (context/wrap-client-ip)
+      handler/site))
 
 (defn start
   "start jetty server

src/clj_rpc/user_data.clj

@@ -25,16 +25,19 @@
   "存储用户数据，如果原来没有token，那么创建一个新的token
    返回 data"
   [data]
-  (do (if (not @*atom-token*) (reset! *atom-token* (uuid)) )
-      (swap! atom-user-datas assoc @*atom-token* data )
-      data))
+  (do
+    ;;treat @atom-token* "" as nil
+    (if (not (seq @*atom-token*)) (reset! *atom-token* (uuid)) )
+    (swap! atom-user-datas assoc @*atom-token* data )
+    data))
 
 (defn delete-user-data!
   "删除用户相关数据,
   纯粹副作用，返回nil"
   []
   (do
     (swap! atom-user-datas dissoc @*atom-token*)
+    (reset! *atom-token* "")
     nil))
 
 ;;TODO 增加用户数据定期清理

test/clj_rpc/test/context.clj

@@ -1,33 +1,45 @@
 (ns clj-rpc.test.context
   (:use [clj-rpc.context :reload true]
-        [clojure.test])
+        [clojure.test]
+        [midje.sweet])
   (:require [clj-rpc.command :as command]))
 
-
 (deftest check-add-context-to-command-map
   (let [command-map {"str" (command/mk-command "str" #'str)
                      "concat" (command/mk-command "concat" #'concat)}
-        options {:require-context true :params-check {0 1}}
+        options [ [:require-context true] [:params-check {0 1}]]
         new-map (add-context-to-command-map command-map options)
         vs (vals new-map)]
-    (is (= (get-in (first vs) [:params-check]) {0 1}))
-    (is (= (get-in (second vs) [:params-check]) {0 1}))))
+    (is (= (get (first vs) :options) options))
+    (is (= (get (second vs) :options) options))))
 
-(deftest test-check-context
+(facts 
   "check whether or not the command and params statifies context requirement"
   (let [cmd (->  (command/mk-command "concat" #'concat)
-                 (add-context {:require-context true
-                               :params-checks {0 [:p1] 1 [:p2]}}))
-        cmd-not-require (command/mk-command "str" #'str)]
-    (is (nil? (check-context cmd {:p1 [1 2] :p2 [3 4]}
-                             [ [1 2] [3 4] [5 6]]))
-        "stastify authorized and params requirement")
-    (is (= :unauthorized (:code (check-context cmd nil [ [1 2] [3 4] [5 6]])))
-        "do not statify authorization requirement")
-    (is (= :unauthorized (:code (check-context cmd {} [ [1 2] [3 4] [5 6]])))
-        "do not statify authorization requirement")
-    (is (= :invalid-params (:code (check-context cmd {:p1 [1 2]}
-                                                 [ [1 2] [3 4] [5 6]])))
-        "do not statify params check requirement")
-    (is (nil? (check-context cmd-not-require nil ["str1" "str2"]))
-        "do not require context check")))
+                 (add-context [ [:require-context true]
+                                [:params-check {0 [:p1] 1 [:p2]}]]))
+        cmd-not-require (command/mk-command "str" #'str)
+        method-request {:method "method" :params [ [1 2] [3 4] [5 6]]}]
+    ;;stastify authorized and params requirement
+    (adjust-method-request cmd {:context {:p1 [1 2] :p2 [3 4]}}
+                   method-request) => method-request
+
+    ;;do not statify authorization requirement
+    (adjust-method-request cmd nil method-request) => (contains {:error {:code :unauthorized}})
+    (adjust-method-request cmd {} method-request) => (contains {:error {:code :unauthorized}})
+
+    ;;do not statify params check requirement
+    (get-in (adjust-method-request cmd {:context {:p1 [1 2] }} method-request)
+            [:error :code]) => :invalid-params
+
+    ;;do not require context check
+    (adjust-method-request cmd-not-require nil {:method "method" :params ["str1" "str2"]})
+    => {:method "method" :params ["str1" "str2"]}))
+
+;.;. The work itself praises the master. -- CPE Bach
+(facts "test inject parasm"
+  (let [cmd (->  (command/mk-command "str" #'str)
+                 (add-context {:params-inject [ [:remote-addr] [:inject]]})) ]
+    (adjust-method-request cmd {:remote-addr "192.168.1.1" :inject "inject-param2"}
+                                     {:method "method" :params ["p1" "p2"]})
+    => {:method "method" :params ["192.168.1.1" "inject-param2" "p1" "p2"]}))