added tree to request router (#38)

Author: johnpatek

include/webframe.hpp

@@ -74,6 +74,16 @@ namespace webframe
     class request
     {
     public:
+        /**
+         * @brief URL variables extracted from the request path
+         * @details If the request path matches a route with variables, the variables will be extracted
+         * and stored in this vector. The order of the variables corresponds to the order of the placeholders
+         * in the route definition.
+         *
+         * TODO: find a cleaner way to do this.
+         */
+        std::vector<std::string> path_variables;
+
         /**
          * @brief get the HTTP method of the request
          * @return the HTTP method of the request
@@ -86,30 +96,30 @@ namespace webframe
         virtual std::string get_path() const = 0;
 
         virtual std::string get_uri() const = 0;
-        
+
         /**
          * @brief get the value of a specific header
          * @param key the header key
          * @param value reference to the header value
-         * @return true if the header exists, false otherwise. The string reference will only 
+         * @return true if the header exists, false otherwise. The string reference will only
          * be set if the header exists.
          */
         virtual bool get_header(const std::string &key, std::string &value) const = 0;
 
         /**
          * @brief get the body of the request as a pointer and size
          * @return a pair containing a pointer to the body data and the size of the body
-         * @details The body data is not guaranteed to be null-terminated. The pointer and size are only 
-         * valid for the duration of the request handling. If the request does not have a body, the pointer 
+         * @details The body data is not guaranteed to be null-terminated. The pointer and size are only
+         * valid for the duration of the request handling. If the request does not have a body, the pointer
          * will be null and the size will be zero.
          */
         virtual std::pair<const uint8_t *, size_t> get_body() const = 0;
 
         /**
          * @brief read the body of the request using a callback
          * @param callback a function to be called with the body data and size
-         * @details The callback will be called with chunks of the body data. None of the runtimes are 
-         * currently capable of streaming request bodies, so the callback will be called at most once with the 
+         * @details The callback will be called with chunks of the body data. None of the runtimes are
+         * currently capable of streaming request bodies, so the callback will be called at most once with the
          * entire body. If there is no request body, the callback will not be called.
          */
         virtual void read_body(const std::function<void(const uint8_t *, size_t)> &callback) const = 0;
@@ -126,34 +136,34 @@ namespace webframe
         /**
          * @brief set the HTTP status code of the response
          * @param status_code the HTTP status code
-         * @details The status code is not checked against valid HTTP status codes. It can be set to 
+         * @details The status code is not checked against valid HTTP status codes. It can be set to
          * any integer value, but there is no guarantee that the runtime implementation will accept it.
          */
         virtual void set_status(int status_code) = 0;
-        
+
         /**
          * @brief set a header of the response
          * @param key the header key
          * @param value the header value
          * @details The headers are not validated, and there is no standard way to handle duplicate entries.
          */
         virtual void set_header(const std::string &key, const std::string &value) = 0;
-        
+
         /**
          * @brief set the body of the response
          * @param data pointer to the body data
          * @param size the size of the body data
-         * @details This must be called once after the status and headers have been set. If it is called 
-         * before, the status will be 200 and the headers will be empty. There is no standard way to handle 
+         * @details This must be called once after the status and headers have been set. If it is called
+         * before, the status will be 200 and the headers will be empty. There is no standard way to handle
          * multiple calls.
          */
         virtual void set_body(const uint8_t *data, size_t size) = 0;
 
         /**
          * @brief write the body of the response using a callback
          * @param callback a function to be called with a chunk to set the body data and size.
-         * @details The callback will be called with chunks of the body data until it returns false to indicate 
-         * end-of-stream. The callback will always be called at least once, and will only populate the chunk if 
+         * @details The callback will be called with chunks of the body data until it returns false to indicate
+         * end-of-stream. The callback will always be called at least once, and will only populate the chunk if
          * the data is not null and the size is greater than zero.
          */
         virtual void write_body(const std::function<bool(std::pair<const uint8_t *, size_t> &)> &callback) = 0;
@@ -162,7 +172,7 @@ namespace webframe
     /**
      * @class runtime
      * @brief abstract interface for WebFrame runtimes
-     * @details Given an application and a router, the runtime is responsible for abstracting HTTP traffic from the 
+     * @details Given an application and a router, the runtime is responsible for abstracting HTTP traffic from the
      * underlying platform. The user will rarely, if ever, interact with this interface directly.
      */
     class runtime
@@ -178,7 +188,7 @@ namespace webframe
          * @param a the application to dispatch
          * @param r the router to use for dispatching requests
          * @return the exit code of the application
-         * @details This is only used for the Win32 desktop runtime. You should not call this directly. Use the WEBFRAME_MAIN macro 
+         * @details This is only used for the Win32 desktop runtime. You should not call this directly. Use the WEBFRAME_MAIN macro
          * to define the entry point of your application, and it will call this function for you.
          */
         virtual int dispatch(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow, application *a, router *r) = 0;
@@ -190,7 +200,7 @@ namespace webframe
          * @param a the application to dispatch
          * @param r the router to use for dispatching requests
          * @return the exit code of the application
-         * @details This is used for all non-Win32 runtimes, including Windows servers. Like the other dispatch function, it 
+         * @details This is used for all non-Win32 runtimes, including Windows servers. Like the other dispatch function, it
          * should not be called directly.
          */
         virtual int dispatch(int argc, const char **argv, application *a, router *r) = 0;

include/webframe/router.hpp

@@ -19,26 +19,55 @@
 #ifndef WEBFRAME_ROUTER_HPP
 #define WEBFRAME_ROUTER_HPP
 
+#include <memory>
+#include <queue>
 #include <string>
 #include <unordered_map>
+#include <vector>
 
 namespace webframe
 {
     class request;
     class response;
     class handler;
 
+    class tree_node
+    {
+    public:
+        tree_node() = default;
+        ~tree_node() = default;
+        void add(const std::string& path, handler* h);
+        handler* find(const std::string& path, std::vector<std::string>& variables) const;
+    private:
+        enum class node_type
+        {
+            leaf,
+            token,
+            wildcard
+        };
+        static void split_path(const std::string& path, std::queue<std::string>& tokens);
+        tree_node *push_token(const std::string& token);
+        tree_node *push_wildcard();
+        tree_node *next(const std::string& token, std::vector<std::string>& variables) const;
+        tree_node *next_token(const std::string& token) const;
+        tree_node *next_wildcard(const std::string& token, std::vector<std::string>& variables) const;
+        std::unique_ptr<std::unordered_map<std::string, std::unique_ptr<tree_node>>> _token_nodes;
+        std::unique_ptr<tree_node> _wildcard_node;
+        node_type _type = node_type::leaf;
+        handler *_handler = nullptr;
+    };
+
     class router
     {
     public:
         router() = default;
         ~router() = default;
         void add_route(const std::string& path, handler* h);
-        handler *find_route(const std::string& path);
+        handler *find_route(const std::string& path, std::vector<std::string>& variables) const;
         void set_default(handler* h);
-        handler* get_default();
+        handler* get_default() const;
     private:        
-        std::unordered_map<std::string, handler*> _handlers;
+        tree_node _root;
         handler* _default_handler = nullptr;
     };
 }

src/router.cpp

@@ -21,22 +21,22 @@
 class global_default_handler : public webframe::handler
 {
 protected:
-    void handle_get(const webframe::request* req, webframe::response* res) override
+    void handle_get(const webframe::request *req, webframe::response *res) override
     {
         throw webframe::exception::not_found;
     }
 
-    void handle_post(const webframe::request* req, webframe::response* res) override
+    void handle_post(const webframe::request *req, webframe::response *res) override
     {
         throw webframe::exception::not_found;
     }
 
-    void handle_put(const webframe::request* req, webframe::response* res) override
+    void handle_put(const webframe::request *req, webframe::response *res) override
     {
         throw webframe::exception::not_found;
     }
 
-    void handle_delete(const webframe::request* req, webframe::response* res) override
+    void handle_delete(const webframe::request *req, webframe::response *res) override
     {
         throw webframe::exception::not_found;
     }
@@ -46,27 +46,146 @@ static global_default_handler g_default_handler;
 
 namespace webframe
 {
-    void router::add_route(const std::string& path, handler* h)
+    void tree_node::add(const std::string &path, handler *h)
     {
-        _handlers[path] = h;
+        std::queue<std::string> tokens;
+        split_path(path, tokens);
+        tree_node *current = this;
+        while (!tokens.empty())
+        {
+            const std::string &token = tokens.front();
+            if (token == "*")
+            {
+                current = current->push_wildcard();
+            }
+            else
+            {
+                current = current->push_token(token);
+            }
+            tokens.pop();
+        }
+        current->_handler = h;
     }
 
-    void router::set_default(handler* h)
+    handler *tree_node::find(const std::string &path, std::vector<std::string> &variables) const
     {
-        _default_handler = h;
+        std::queue<std::string> tokens;
+        split_path(path, tokens);
+        const tree_node *current = this;
+        while (!tokens.empty() && current)
+        {
+            const std::string &token = tokens.front();
+            current = current->next(token, variables);
+            tokens.pop();
+        }
+        return current ? current->_handler : nullptr;
+    }
+
+    void tree_node::split_path(const std::string &path, std::queue<std::string> &tokens)
+    {
+        size_t start, end;
+        if (!path.empty() && path != "/")
+        {
+            start = 0;
+            while (start < path.size())
+            {
+                size_t end = path.find('/', start);
+                if (end == std::string::npos)
+                {
+                    end = path.size();
+                }
+                if (end > start)
+                {
+                    tokens.push(path.substr(start, end - start));
+                }
+                start = end + 1;
+            }
+        }
+    }
+
+    tree_node *tree_node::push_token(const std::string &token)
+    {
+        _type = node_type::token;
+        if (!_token_nodes)
+        {
+            _token_nodes = std::make_unique<std::unordered_map<std::string, std::unique_ptr<tree_node>>>();
+        }
+        auto &node_ptr = (*_token_nodes)[token];
+        if (!node_ptr)
+        {
+            node_ptr = std::make_unique<tree_node>();
+        }
+        return node_ptr.get();
+    }
+
+    tree_node *tree_node::push_wildcard()
+    {
+        _type = node_type::wildcard;
+        if (!_wildcard_node)
+        {
+            _wildcard_node = std::make_unique<tree_node>();
+        }
+        return _wildcard_node.get();
+    }
+
+    tree_node *tree_node::next(const std::string &token, std::vector<std::string> &variables) const
+    {
+        tree_node *node(nullptr);
+        switch(_type)
+        {
+            case node_type::token:
+                node = next_token(token);
+                break;
+            case node_type::wildcard:
+                node = next_wildcard(token, variables);
+                break;
+            default:
+                break;
+        }
+        return node;
     }
 
-    handler* router::find_route(const std::string& path)
+    tree_node *tree_node::next_token(const std::string &token) const
     {
-        auto it = _handlers.find(path);
-        if (it != _handlers.end()) {
-            return it->second;
+        tree_node *node(nullptr);
+        if (_token_nodes)
+        {
+            auto it = _token_nodes->find(token);
+            if (it != _token_nodes->end())
+            {
+                node = it->second.get();
+            }
         }
-        return get_default();
+        return node;
+    }
+
+    tree_node *tree_node::next_wildcard(const std::string& token, std::vector<std::string> &variables) const
+    {
+        if (_wildcard_node)
+        {
+            variables.push_back(token);
+        }
+        return _wildcard_node ? _wildcard_node.get() : nullptr;
+    }
+
+    void router::add_route(const std::string &path, handler *h)
+    {
+        _root.add(path, h);
+    }
+
+    void router::set_default(handler *h)
+    {
+        _default_handler = h;
+    }
+
+    handler *router::find_route(const std::string &path, std::vector<std::string> &variables) const
+    {
+        handler *h = _root.find(path, variables);
+        return h ? h : get_default();
     }
 
-    handler* router::get_default()
+    handler *router::get_default() const
     {
-        return _default_handler ? _default_handler : &g_default_handler;      
+        return _default_handler ? _default_handler : &g_default_handler;
     }
 }

src/runtimes/desktop/webview.cpp

@@ -18,7 +18,7 @@ namespace webframe
             bool sent(false);
             webframe::desktop::request req(&request);
             webframe::desktop::response res(response.get(), sent);
-            webframe::handler *handler = _router->find_route(req.get_path());
+            webframe::handler *handler = _router->find_route(req.get_path(), req.path_variables);
             handler->handle_request(&req, &res);
             if (!sent)
             {

src/runtimes/server/runtime.cpp

@@ -39,7 +39,7 @@ static void evhttp_callback(struct evhttp_request *req, void *arg)
     webframe::router *runtime = static_cast<webframe::router *>(arg);
     webframe::server::request request(req);
     webframe::server::response response(req, sent_response, status);
-    webframe::handler *handler = runtime->find_route(request.get_path());
+    webframe::handler *handler = runtime->find_route(request.get_path(), request.path_variables);
     handler->handle_request(&request, &response);
     if (!sent_response)
     {

tests/src/client.cpp

@@ -26,7 +26,8 @@ namespace webframe::test
 
     void client::run(const webframe::request *request, webframe::response *response)
     {
-        webframe::handler *handler = _router->find_route(request->get_path());
+        std::vector<std::string> variables;
+        webframe::handler *handler = _router->find_route(request->get_path(), variables);
         handler->handle_request(request, response);
     }
 }