| // Copyright 2012 the V8 project authors. All rights reserved. |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following |
| // disclaimer in the documentation and/or other materials provided |
| // with the distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived |
| // from this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #include <v8.h> |
| |
| #include <string> |
| #include <map> |
| |
| #ifdef COMPRESS_STARTUP_DATA_BZ2 |
| #error Using compressed startup data is not supported for this sample |
| #endif |
| |
| using namespace std; |
| using namespace v8; |
| |
| // These interfaces represent an existing request processing interface. |
| // The idea is to imagine a real application that uses these interfaces |
| // and then add scripting capabilities that allow you to interact with |
| // the objects through JavaScript. |
| |
| /** |
| * A simplified http request. |
| */ |
| class HttpRequest { |
| public: |
| virtual ~HttpRequest() { } |
| virtual const string& Path() = 0; |
| virtual const string& Referrer() = 0; |
| virtual const string& Host() = 0; |
| virtual const string& UserAgent() = 0; |
| }; |
| |
| /** |
| * The abstract superclass of http request processors. |
| */ |
| class HttpRequestProcessor { |
| public: |
| virtual ~HttpRequestProcessor() { } |
| |
| // Initialize this processor. The map contains options that control |
| // how requests should be processed. |
| virtual bool Initialize(map<string, string>* options, |
| map<string, string>* output) = 0; |
| |
| // Process a single request. |
| virtual bool Process(HttpRequest* req) = 0; |
| |
| static void Log(const char* event); |
| }; |
| |
| /** |
| * An http request processor that is scriptable using JavaScript. |
| */ |
| class JsHttpRequestProcessor : public HttpRequestProcessor { |
| public: |
| // Creates a new processor that processes requests by invoking the |
| // Process function of the JavaScript script given as an argument. |
| explicit JsHttpRequestProcessor(Handle<String> script) : script_(script) { } |
| virtual ~JsHttpRequestProcessor(); |
| |
| virtual bool Initialize(map<string, string>* opts, |
| map<string, string>* output); |
| virtual bool Process(HttpRequest* req); |
| |
| private: |
| // Execute the script associated with this processor and extract the |
| // Process function. Returns true if this succeeded, otherwise false. |
| bool ExecuteScript(Handle<String> script); |
| |
| // Wrap the options and output map in a JavaScript objects and |
| // install it in the global namespace as 'options' and 'output'. |
| bool InstallMaps(map<string, string>* opts, map<string, string>* output); |
| |
| // Constructs the template that describes the JavaScript wrapper |
| // type for requests. |
| static Handle<ObjectTemplate> MakeRequestTemplate(); |
| static Handle<ObjectTemplate> MakeMapTemplate(); |
| |
| // Callbacks that access the individual fields of request objects. |
| static Handle<Value> GetPath(Local<String> name, const AccessorInfo& info); |
| static Handle<Value> GetReferrer(Local<String> name, |
| const AccessorInfo& info); |
| static Handle<Value> GetHost(Local<String> name, const AccessorInfo& info); |
| static Handle<Value> GetUserAgent(Local<String> name, |
| const AccessorInfo& info); |
| |
| // Callbacks that access maps |
| static Handle<Value> MapGet(Local<String> name, const AccessorInfo& info); |
| static Handle<Value> MapSet(Local<String> name, |
| Local<Value> value, |
| const AccessorInfo& info); |
| |
| // Utility methods for wrapping C++ objects as JavaScript objects, |
| // and going back again. |
| Handle<Object> WrapMap(map<string, string>* obj); |
| static map<string, string>* UnwrapMap(Handle<Object> obj); |
| Handle<Object> WrapRequest(HttpRequest* obj); |
| static HttpRequest* UnwrapRequest(Handle<Object> obj); |
| |
| Isolate* GetIsolate() { return context_->GetIsolate(); } |
| |
| Handle<String> script_; |
| Persistent<Context> context_; |
| Persistent<Function> process_; |
| static Persistent<ObjectTemplate> request_template_; |
| static Persistent<ObjectTemplate> map_template_; |
| }; |
| |
| // ------------------------- |
| // --- P r o c e s s o r --- |
| // ------------------------- |
| |
| |
| static Handle<Value> LogCallback(const Arguments& args) { |
| if (args.Length() < 1) return v8::Undefined(); |
| HandleScope scope; |
| Handle<Value> arg = args[0]; |
| String::Utf8Value value(arg); |
| HttpRequestProcessor::Log(*value); |
| return v8::Undefined(); |
| } |
| |
| |
| // Execute the script and fetch the Process method. |
| bool JsHttpRequestProcessor::Initialize(map<string, string>* opts, |
| map<string, string>* output) { |
| // Create a handle scope to hold the temporary references. |
| HandleScope handle_scope; |
| |
| // Create a template for the global object where we set the |
| // built-in global functions. |
| Handle<ObjectTemplate> global = ObjectTemplate::New(); |
| global->Set(String::New("log"), FunctionTemplate::New(LogCallback)); |
| |
| // Each processor gets its own context so different processors don't |
| // affect each other. Context::New returns a persistent handle which |
| // is what we need for the reference to remain after we return from |
| // this method. That persistent handle has to be disposed in the |
| // destructor. |
| context_ = Context::New(NULL, global); |
| |
| // Enter the new context so all the following operations take place |
| // within it. |
| Context::Scope context_scope(context_); |
| |
| // Make the options mapping available within the context |
| if (!InstallMaps(opts, output)) |
| return false; |
| |
| // Compile and run the script |
| if (!ExecuteScript(script_)) |
| return false; |
| |
| // The script compiled and ran correctly. Now we fetch out the |
| // Process function from the global object. |
| Handle<String> process_name = String::New("Process"); |
| Handle<Value> process_val = context_->Global()->Get(process_name); |
| |
| // If there is no Process function, or if it is not a function, |
| // bail out |
| if (!process_val->IsFunction()) return false; |
| |
| // It is a function; cast it to a Function |
| Handle<Function> process_fun = Handle<Function>::Cast(process_val); |
| |
| // Store the function in a Persistent handle, since we also want |
| // that to remain after this call returns |
| process_ = Persistent<Function>::New(GetIsolate(), process_fun); |
| |
| // All done; all went well |
| return true; |
| } |
| |
| |
| bool JsHttpRequestProcessor::ExecuteScript(Handle<String> script) { |
| HandleScope handle_scope; |
| |
| // We're just about to compile the script; set up an error handler to |
| // catch any exceptions the script might throw. |
| TryCatch try_catch; |
| |
| // Compile the script and check for errors. |
| Handle<Script> compiled_script = Script::Compile(script); |
| if (compiled_script.IsEmpty()) { |
| String::Utf8Value error(try_catch.Exception()); |
| Log(*error); |
| // The script failed to compile; bail out. |
| return false; |
| } |
| |
| // Run the script! |
| Handle<Value> result = compiled_script->Run(); |
| if (result.IsEmpty()) { |
| // The TryCatch above is still in effect and will have caught the error. |
| String::Utf8Value error(try_catch.Exception()); |
| Log(*error); |
| // Running the script failed; bail out. |
| return false; |
| } |
| return true; |
| } |
| |
| |
| bool JsHttpRequestProcessor::InstallMaps(map<string, string>* opts, |
| map<string, string>* output) { |
| HandleScope handle_scope; |
| |
| // Wrap the map object in a JavaScript wrapper |
| Handle<Object> opts_obj = WrapMap(opts); |
| |
| // Set the options object as a property on the global object. |
| context_->Global()->Set(String::New("options"), opts_obj); |
| |
| Handle<Object> output_obj = WrapMap(output); |
| context_->Global()->Set(String::New("output"), output_obj); |
| |
| return true; |
| } |
| |
| |
| bool JsHttpRequestProcessor::Process(HttpRequest* request) { |
| // Create a handle scope to keep the temporary object references. |
| HandleScope handle_scope; |
| |
| // Enter this processor's context so all the remaining operations |
| // take place there |
| Context::Scope context_scope(context_); |
| |
| // Wrap the C++ request object in a JavaScript wrapper |
| Handle<Object> request_obj = WrapRequest(request); |
| |
| // Set up an exception handler before calling the Process function |
| TryCatch try_catch; |
| |
| // Invoke the process function, giving the global object as 'this' |
| // and one argument, the request. |
| const int argc = 1; |
| Handle<Value> argv[argc] = { request_obj }; |
| Handle<Value> result = process_->Call(context_->Global(), argc, argv); |
| if (result.IsEmpty()) { |
| String::Utf8Value error(try_catch.Exception()); |
| Log(*error); |
| return false; |
| } else { |
| return true; |
| } |
| } |
| |
| |
| JsHttpRequestProcessor::~JsHttpRequestProcessor() { |
| // Dispose the persistent handles. When noone else has any |
| // references to the objects stored in the handles they will be |
| // automatically reclaimed. |
| v8::Isolate* isolate = GetIsolate(); |
| context_.Dispose(isolate); |
| process_.Dispose(isolate); |
| } |
| |
| |
| Persistent<ObjectTemplate> JsHttpRequestProcessor::request_template_; |
| Persistent<ObjectTemplate> JsHttpRequestProcessor::map_template_; |
| |
| |
| // ----------------------------------- |
| // --- A c c e s s i n g M a p s --- |
| // ----------------------------------- |
| |
| // Utility function that wraps a C++ http request object in a |
| // JavaScript object. |
| Handle<Object> JsHttpRequestProcessor::WrapMap(map<string, string>* obj) { |
| // Handle scope for temporary handles. |
| HandleScope handle_scope; |
| |
| // Fetch the template for creating JavaScript map wrappers. |
| // It only has to be created once, which we do on demand. |
| if (map_template_.IsEmpty()) { |
| Handle<ObjectTemplate> raw_template = MakeMapTemplate(); |
| map_template_ = Persistent<ObjectTemplate>::New(GetIsolate(), raw_template); |
| } |
| Handle<ObjectTemplate> templ = map_template_; |
| |
| // Create an empty map wrapper. |
| Handle<Object> result = templ->NewInstance(); |
| |
| // Wrap the raw C++ pointer in an External so it can be referenced |
| // from within JavaScript. |
| Handle<External> map_ptr = External::New(obj); |
| |
| // Store the map pointer in the JavaScript wrapper. |
| result->SetInternalField(0, map_ptr); |
| |
| // Return the result through the current handle scope. Since each |
| // of these handles will go away when the handle scope is deleted |
| // we need to call Close to let one, the result, escape into the |
| // outer handle scope. |
| return handle_scope.Close(result); |
| } |
| |
| |
| // Utility function that extracts the C++ map pointer from a wrapper |
| // object. |
| map<string, string>* JsHttpRequestProcessor::UnwrapMap(Handle<Object> obj) { |
| Handle<External> field = Handle<External>::Cast(obj->GetInternalField(0)); |
| void* ptr = field->Value(); |
| return static_cast<map<string, string>*>(ptr); |
| } |
| |
| |
| // Convert a JavaScript string to a std::string. To not bother too |
| // much with string encodings we just use ascii. |
| string ObjectToString(Local<Value> value) { |
| String::Utf8Value utf8_value(value); |
| return string(*utf8_value); |
| } |
| |
| |
| Handle<Value> JsHttpRequestProcessor::MapGet(Local<String> name, |
| const AccessorInfo& info) { |
| // Fetch the map wrapped by this object. |
| map<string, string>* obj = UnwrapMap(info.Holder()); |
| |
| // Convert the JavaScript string to a std::string. |
| string key = ObjectToString(name); |
| |
| // Look up the value if it exists using the standard STL ideom. |
| map<string, string>::iterator iter = obj->find(key); |
| |
| // If the key is not present return an empty handle as signal |
| if (iter == obj->end()) return Handle<Value>(); |
| |
| // Otherwise fetch the value and wrap it in a JavaScript string |
| const string& value = (*iter).second; |
| return String::New(value.c_str(), static_cast<int>(value.length())); |
| } |
| |
| |
| Handle<Value> JsHttpRequestProcessor::MapSet(Local<String> name, |
| Local<Value> value_obj, |
| const AccessorInfo& info) { |
| // Fetch the map wrapped by this object. |
| map<string, string>* obj = UnwrapMap(info.Holder()); |
| |
| // Convert the key and value to std::strings. |
| string key = ObjectToString(name); |
| string value = ObjectToString(value_obj); |
| |
| // Update the map. |
| (*obj)[key] = value; |
| |
| // Return the value; any non-empty handle will work. |
| return value_obj; |
| } |
| |
| |
| Handle<ObjectTemplate> JsHttpRequestProcessor::MakeMapTemplate() { |
| HandleScope handle_scope; |
| |
| Handle<ObjectTemplate> result = ObjectTemplate::New(); |
| result->SetInternalFieldCount(1); |
| result->SetNamedPropertyHandler(MapGet, MapSet); |
| |
| // Again, return the result through the current handle scope. |
| return handle_scope.Close(result); |
| } |
| |
| |
| // ------------------------------------------- |
| // --- A c c e s s i n g R e q u e s t s --- |
| // ------------------------------------------- |
| |
| /** |
| * Utility function that wraps a C++ http request object in a |
| * JavaScript object. |
| */ |
| Handle<Object> JsHttpRequestProcessor::WrapRequest(HttpRequest* request) { |
| // Handle scope for temporary handles. |
| HandleScope handle_scope; |
| |
| // Fetch the template for creating JavaScript http request wrappers. |
| // It only has to be created once, which we do on demand. |
| if (request_template_.IsEmpty()) { |
| Handle<ObjectTemplate> raw_template = MakeRequestTemplate(); |
| request_template_ = |
| Persistent<ObjectTemplate>::New(GetIsolate(), raw_template); |
| } |
| Handle<ObjectTemplate> templ = request_template_; |
| |
| // Create an empty http request wrapper. |
| Handle<Object> result = templ->NewInstance(); |
| |
| // Wrap the raw C++ pointer in an External so it can be referenced |
| // from within JavaScript. |
| Handle<External> request_ptr = External::New(request); |
| |
| // Store the request pointer in the JavaScript wrapper. |
| result->SetInternalField(0, request_ptr); |
| |
| // Return the result through the current handle scope. Since each |
| // of these handles will go away when the handle scope is deleted |
| // we need to call Close to let one, the result, escape into the |
| // outer handle scope. |
| return handle_scope.Close(result); |
| } |
| |
| |
| /** |
| * Utility function that extracts the C++ http request object from a |
| * wrapper object. |
| */ |
| HttpRequest* JsHttpRequestProcessor::UnwrapRequest(Handle<Object> obj) { |
| Handle<External> field = Handle<External>::Cast(obj->GetInternalField(0)); |
| void* ptr = field->Value(); |
| return static_cast<HttpRequest*>(ptr); |
| } |
| |
| |
| Handle<Value> JsHttpRequestProcessor::GetPath(Local<String> name, |
| const AccessorInfo& info) { |
| // Extract the C++ request object from the JavaScript wrapper. |
| HttpRequest* request = UnwrapRequest(info.Holder()); |
| |
| // Fetch the path. |
| const string& path = request->Path(); |
| |
| // Wrap the result in a JavaScript string and return it. |
| return String::New(path.c_str(), static_cast<int>(path.length())); |
| } |
| |
| |
| Handle<Value> JsHttpRequestProcessor::GetReferrer(Local<String> name, |
| const AccessorInfo& info) { |
| HttpRequest* request = UnwrapRequest(info.Holder()); |
| const string& path = request->Referrer(); |
| return String::New(path.c_str(), static_cast<int>(path.length())); |
| } |
| |
| |
| Handle<Value> JsHttpRequestProcessor::GetHost(Local<String> name, |
| const AccessorInfo& info) { |
| HttpRequest* request = UnwrapRequest(info.Holder()); |
| const string& path = request->Host(); |
| return String::New(path.c_str(), static_cast<int>(path.length())); |
| } |
| |
| |
| Handle<Value> JsHttpRequestProcessor::GetUserAgent(Local<String> name, |
| const AccessorInfo& info) { |
| HttpRequest* request = UnwrapRequest(info.Holder()); |
| const string& path = request->UserAgent(); |
| return String::New(path.c_str(), static_cast<int>(path.length())); |
| } |
| |
| |
| Handle<ObjectTemplate> JsHttpRequestProcessor::MakeRequestTemplate() { |
| HandleScope handle_scope; |
| |
| Handle<ObjectTemplate> result = ObjectTemplate::New(); |
| result->SetInternalFieldCount(1); |
| |
| // Add accessors for each of the fields of the request. |
| result->SetAccessor(String::NewSymbol("path"), GetPath); |
| result->SetAccessor(String::NewSymbol("referrer"), GetReferrer); |
| result->SetAccessor(String::NewSymbol("host"), GetHost); |
| result->SetAccessor(String::NewSymbol("userAgent"), GetUserAgent); |
| |
| // Again, return the result through the current handle scope. |
| return handle_scope.Close(result); |
| } |
| |
| |
| // --- Test --- |
| |
| |
| void HttpRequestProcessor::Log(const char* event) { |
| printf("Logged: %s\n", event); |
| } |
| |
| |
| /** |
| * A simplified http request. |
| */ |
| class StringHttpRequest : public HttpRequest { |
| public: |
| StringHttpRequest(const string& path, |
| const string& referrer, |
| const string& host, |
| const string& user_agent); |
| virtual const string& Path() { return path_; } |
| virtual const string& Referrer() { return referrer_; } |
| virtual const string& Host() { return host_; } |
| virtual const string& UserAgent() { return user_agent_; } |
| private: |
| string path_; |
| string referrer_; |
| string host_; |
| string user_agent_; |
| }; |
| |
| |
| StringHttpRequest::StringHttpRequest(const string& path, |
| const string& referrer, |
| const string& host, |
| const string& user_agent) |
| : path_(path), |
| referrer_(referrer), |
| host_(host), |
| user_agent_(user_agent) { } |
| |
| |
| void ParseOptions(int argc, |
| char* argv[], |
| map<string, string>& options, |
| string* file) { |
| for (int i = 1; i < argc; i++) { |
| string arg = argv[i]; |
| size_t index = arg.find('=', 0); |
| if (index == string::npos) { |
| *file = arg; |
| } else { |
| string key = arg.substr(0, index); |
| string value = arg.substr(index+1); |
| options[key] = value; |
| } |
| } |
| } |
| |
| |
| // Reads a file into a v8 string. |
| Handle<String> ReadFile(const string& name) { |
| FILE* file = fopen(name.c_str(), "rb"); |
| if (file == NULL) return Handle<String>(); |
| |
| fseek(file, 0, SEEK_END); |
| int size = ftell(file); |
| rewind(file); |
| |
| char* chars = new char[size + 1]; |
| chars[size] = '\0'; |
| for (int i = 0; i < size;) { |
| int read = static_cast<int>(fread(&chars[i], 1, size - i, file)); |
| i += read; |
| } |
| fclose(file); |
| Handle<String> result = String::New(chars, size); |
| delete[] chars; |
| return result; |
| } |
| |
| |
| const int kSampleSize = 6; |
| StringHttpRequest kSampleRequests[kSampleSize] = { |
| StringHttpRequest("/process.cc", "localhost", "google.com", "firefox"), |
| StringHttpRequest("/", "localhost", "google.net", "firefox"), |
| StringHttpRequest("/", "localhost", "google.org", "safari"), |
| StringHttpRequest("/", "localhost", "yahoo.com", "ie"), |
| StringHttpRequest("/", "localhost", "yahoo.com", "safari"), |
| StringHttpRequest("/", "localhost", "yahoo.com", "firefox") |
| }; |
| |
| |
| bool ProcessEntries(HttpRequestProcessor* processor, int count, |
| StringHttpRequest* reqs) { |
| for (int i = 0; i < count; i++) { |
| if (!processor->Process(&reqs[i])) |
| return false; |
| } |
| return true; |
| } |
| |
| |
| void PrintMap(map<string, string>* m) { |
| for (map<string, string>::iterator i = m->begin(); i != m->end(); i++) { |
| pair<string, string> entry = *i; |
| printf("%s: %s\n", entry.first.c_str(), entry.second.c_str()); |
| } |
| } |
| |
| |
| int main(int argc, char* argv[]) { |
| map<string, string> options; |
| string file; |
| ParseOptions(argc, argv, options, &file); |
| if (file.empty()) { |
| fprintf(stderr, "No script was specified.\n"); |
| return 1; |
| } |
| HandleScope scope; |
| Handle<String> source = ReadFile(file); |
| if (source.IsEmpty()) { |
| fprintf(stderr, "Error reading '%s'.\n", file.c_str()); |
| return 1; |
| } |
| JsHttpRequestProcessor processor(source); |
| map<string, string> output; |
| if (!processor.Initialize(&options, &output)) { |
| fprintf(stderr, "Error initializing processor.\n"); |
| return 1; |
| } |
| if (!ProcessEntries(&processor, kSampleSize, kSampleRequests)) |
| return 1; |
| PrintMap(&output); |
| } |