process.cc.svn-base

Google浏览器V8内核代码

  // 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(), 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(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(), 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(), 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(), 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(), 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];
    int 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 = 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);
}