// 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 <include/v8.h>
#include <include/libplatform/libplatform.h>
#include <stdlib.h>
#include <string.h>
#include <map>
#include <string>
using std::map;
using std::pair;
using std::string;
using v8::Context;
using v8::EscapableHandleScope;
using v8::External;
using v8::Function;
using v8::FunctionTemplate;
using v8::Global;
using v8::HandleScope;
using v8::Isolate;
using v8::Local;
using v8::MaybeLocal;
using v8::Name;
using v8::NamedPropertyHandlerConfiguration;
using v8::NewStringType;
using v8::Object;
using v8::ObjectTemplate;
using v8::PropertyCallbackInfo;
using v8::Script;
using v8::String;
using v8::TryCatch;
using v8::Value;
// 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.
JsHttpRequestProcessor(Isolate* isolate, Local<String> script)
: isolate_(isolate), 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(Local<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 Local<ObjectTemplate> MakeRequestTemplate(Isolate* isolate);
static Local<ObjectTemplate> MakeMapTemplate(Isolate* isolate);
// Callbacks that access the individual fields of request objects.
static void GetPath(Local<String> name,
const PropertyCallbackInfo<Value>& info);
static void GetReferrer(Local<String> name,
const PropertyCallbackInfo<Value>& info);
static void GetHost(Local<String> name,
const PropertyCallbackInfo<Value>& info);
static void GetUserAgent(Local<String> name,
const PropertyCallbackInfo<Value>& info);
// Callbacks that access maps
static void MapGet(Local<Name> name, const PropertyCallbackInfo<Value>& info);
static void MapSet(Local<Name> name, Local<Value> value,
const PropertyCallbackInfo<Value>& info);
// Utility methods for wrapping C++ objects as JavaScript objects,
// and going back again.
Local<Object> WrapMap(map<string, string>* obj);
static map<string, string>* UnwrapMap(Local<Object> obj);
Local<Object> WrapRequest(HttpRequest* obj);
static HttpRequest* UnwrapRequest(Local<Object> obj);
Isolate* GetIsolate() { return isolate_; }
Isolate* isolate_;
Local<String> script_;
Global<Context> context_;
Global<Function> process_;
static Global<ObjectTemplate> request_template_;
static Global<ObjectTemplate> map_template_;
};
// -------------------------
// --- P r o c e s s o r ---
// -------------------------
static void LogCallback(const v8::FunctionCallbackInfo<v8::Value>& args) {
if (args.Length() < 1) return;
Isolate* isolate = args.GetIsolate();
HandleScope scope(isolate);
Local<Value> arg = args[0];
String::Utf8Value value(isolate, arg);
HttpRequestProcessor::Log(*value);
}
// 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(GetIsolate());
// Create a template for the global object where we set the
// built-in global functions.
Local<ObjectTemplate> global = ObjectTemplate::New(GetIsolate());
global->Set(String::NewFromUtf8(GetIsolate(), "log", NewStringType::kNormal)
.ToLocalChecked(),
FunctionTemplate::New(GetIsolate(), 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.
v8::Local<v8::Context> context = Context::New(GetIsolate(), NULL, global);
context_.Reset(GetIsolate(), context);
// 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.
Local<String> process_name =
String::NewFromUtf8(GetIsolate(), "Process", NewStringType::kNormal)
.ToLocalChecked();
Local<Value> process_val;
// If there is no Process function, or if it is not a function,
// bail out
if (!context->Global()->Get(context, process_name).ToLocal(&process_val) ||
!process_val->IsFunction()) {
return false;
}
// It is a function; cast it to a Function
Local<Function> process_fun = Local<Function>::Cast(process_val);
// Store the function in a Global handle, since we also want
// that to remain after this call returns
process_.Reset(GetIsolate(), process_fun);
// All done; all went well
return true;
}
bool JsHttpRequestProcessor::ExecuteScript(Local<String> script) {
HandleScope handle_scope(GetIsolate());
// We're just about to compile the script; set up an error handler to
// catch any exceptions the script might throw.
TryCatch try_catch(GetIsolate());
Local<Context> context(GetIsolate()->GetCurrentContext());
// Compile the script and check for errors.
Local<Script> compiled_script;
if (!Script::Compile(context, script).ToLocal(&compiled_script)) {
String::Utf8Value error(GetIsolate(), try_catch.Exception());
Log(*error);
// The script failed to compile; bail out.
return false;
}
// Run the script!
Local<Value> result;
if (!compiled_script->Run(context).ToLocal(&result)) {
// The TryCatch above is still in effect and will have caught the error.
String::Utf8Value error(GetIsolate(), 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(GetIsolate());
// Wrap the map object in a JavaScript wrapper
Local<Object> opts_obj = WrapMap(opts);
v8::Local<v8::Context> context =
v8::Local<v8::Context>::New(GetIsolate(), context_);
// Set the options object as a property on the global object.
context->Global()
->Set(context,
String::NewFromUtf8(GetIsolate(), "options", NewStringType::kNormal)
.ToLocalChecked(),
opts_obj)
.FromJust();
Local<Object> output_obj = WrapMap(output);
context->Global()
->Set(context,
String::NewFromUtf8(GetIsolate(), "output", NewStringType::kNormal)
.ToLocalChecked(),
output_obj)
.FromJust();
return true;
}
bool JsHttpRequestProcessor::Process(HttpRequest* request) {
// Create a handle scope to keep the temporary object references.
HandleScope handle_scope(GetIsolate());
v8::Local<v8::Context> context =
v8::Local<v8::Context>::New(GetIsolate(), context_);
// 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
Local<Object> request_obj = WrapRequest(request);
// Set up an exception handler before calling the Process function
TryCatch try_catch(GetIsolate());
// Invoke the process function, giving the global object as 'this'
// and one argument, the request.
const int argc = 1;
Local<Value> argv[argc] = {request_obj};
v8::Local<v8::Function> process =
v8::Local<v8::Function>::New(GetIsolate(), process_);
Local<Value> result;
if (!process->Call(context, context->Global(), argc, argv).ToLocal(&result)) {
String::Utf8Value error(GetIsolate(), try_catch.Exception());
Log(*error);
return false;
}
return true;
}
JsHttpRequestProcessor::~JsHttpRequestProcessor() {
// Dispose the persistent handles. When no one else has any
// references to the objects stored in the handles they will be
// automatically reclaimed.
context_.Reset();
process_.Reset();
}
Global<ObjectTemplate> JsHttpRequestProcessor::request_template_;
Global<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.
Local<Object> JsHttpRequestProcessor::WrapMap(map<string, string>* obj) {
// Local scope for temporary handles.
EscapableHandleScope handle_scope(GetIsolate());
// Fetch the template for creating JavaScript map wrappers.
// It only has to be created once, which we do on demand.
if (map_template_.IsEmpty()) {
Local<ObjectTemplate> raw_template = MakeMapTemplate(GetIsolate());
map_template_.Reset(GetIsolate(), raw_template);
}
Local<ObjectTemplate> templ =
Local<ObjectTemplate>::New(GetIsolate(), map_template_);
// Create an empty map wrapper.
Local<Object> result =
templ->NewInstance(GetIsolate()->GetCurrentContext()).ToLocalChecked();
// Wrap the raw C++ pointer in an External so it can be referenced
// from within JavaScript.
Local<External> map_ptr = External::New(GetIsolate(), 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.Escape(result);
}
// Utility function that extracts the C++ map pointer from a wrapper
// object.
map<string, string>* JsHttpRequestProcessor::UnwrapMap(Local<Object> obj) {
Local<External> field = Local<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(v8::Isolate* isolate, Local<Value> value) {
String::Utf8Value utf8_value(isolate, value);
return string(*utf8_value);
}
void JsHttpRequestProcessor::MapGet(Local<Name> name,
const PropertyCallbackInfo<Value>& info) {
if (name->IsSymbol()) return;
// 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(info.GetIsolate(), Local<String>::Cast(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;
// Otherwise fetch the value and wrap it in a JavaScript string
const string& value = (*iter).second;
info.GetReturnValue().Set(
String::NewFromUtf8(info.GetIsolate(), value.c_str(),
NewStringType::kNormal,
static_cast<int>(value.length())).ToLocalChecked());
}
void JsHttpRequestProcessor::MapSet(Local<Name> name, Local<Value> value_obj,
const PropertyCallbackInfo<Value>& info) {
if (name->IsSymbol()) return;
// 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(info.GetIsolate(), Local<String>::Cast(name));
string value = ObjectToString(info.GetIsolate(), value_obj);
// Update the map.
(*obj)[key] = value;
// Return the value; any non-empty handle will work.
info.GetReturnValue().Set(value_obj);
}
Local<ObjectTemplate> JsHttpRequestProcessor::MakeMapTemplate(
Isolate* isolate) {
EscapableHandleScope handle_scope(isolate);
Local<ObjectTemplate> result = ObjectTemplate::New(isolate);
result->SetInternalFieldCount(1);
result->SetHandler(NamedPropertyHandlerConfiguration(MapGet, MapSet));
// Again, return the result through the current handle scope.
return handle_scope.Escape(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.
*/
Local<Object> JsHttpRequestProcessor::WrapRequest(HttpRequest* request) {
// Local scope for temporary handles.
EscapableHandleScope handle_scope(GetIsolate());
// 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()) {
Local<ObjectTemplate> raw_template = MakeRequestTemplate(GetIsolate());
request_template_.Reset(GetIsolate(), raw_template);
}
Local<ObjectTemplate> templ =
Local<ObjectTemplate>::New(GetIsolate(), request_template_);
// Create an empty http request wrapper.
Local<Object> result =
templ->NewInstance(GetIsolate()->GetCurrentContext()).ToLocalChecked();
// Wrap the raw C++ pointer in an External so it can be referenced
// from within JavaScript.
Local<External> request_ptr = External::New(GetIsolate(), 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.Escape(result);
}
/**
* Utility function that extracts the C++ http request object from a
* wrapper object.
*/
HttpRequest* JsHttpRequestProcessor::UnwrapRequest(Local<Object> obj) {
Local<External> field = Local<External>::Cast(obj->GetInternalField(0));
void* ptr = field->Value();
return static_cast<HttpRequest*>(ptr);
}
void JsHttpRequestProcessor::GetPath(Local<String> name,
const PropertyCallbackInfo<Value>& 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.
info.GetReturnValue().Set(
String::NewFromUtf8(info.GetIsolate(), path.c_str(),
NewStringType::kNormal,
static_cast<int>(path.length())).ToLocalChecked());
}
void JsHttpRequestProcessor::GetReferrer(
Local<String> name,
const PropertyCallbackInfo<Value>& info) {
HttpRequest* request = UnwrapRequest(info.Holder());
const string& path = request->Referrer();
info.GetReturnValue().Set(
String::NewFromUtf8(info.GetIsolate(), path.c_str(),
NewStringType::kNormal,
static_cast<int>(path.length())).ToLocalChecked());
}
void JsHttpRequestProcessor::GetHost(Local<String> name,
const PropertyCallbackInfo<Value>& info) {
HttpRequest* request = UnwrapRequest(info.Holder());
const string& path = request->Host();
info.GetReturnValue().Set(
String::NewFromUtf8(info.GetIsolate(), path.c_str(),
NewStringType::kNormal,
static_cast<int>(path.length())).ToLocalChecked());
}
void JsHttpRequestProcessor::GetUserAgent(
Local<String> name,
const PropertyCallbackInfo<Value>& info) {
HttpRequest* request = UnwrapRequest(info.Holder());
const string& path = request->UserAgent();
info.GetReturnValue().Set(
String::NewFromUtf8(info.GetIsolate(), path.c_str(),
NewStringType::kNormal,
static_cast<int>(path.length())).ToLocalChecked());
}
Local<ObjectTemplate> JsHttpRequestProcessor::MakeRequestTemplate(
Isolate* isolate) {
EscapableHandleScope handle_scope(isolate);
Local<ObjectTemplate> result = ObjectTemplate::New(isolate);
result->SetInternalFieldCount(1);
// Add accessors for each of the fields of the request.
result->SetAccessor(
String::NewFromUtf8(isolate, "path", NewStringType::kInternalized)
.ToLocalChecked(),
GetPath);
result->SetAccessor(
String::NewFromUtf8(isolate, "referrer", NewStringType::kInternalized)
.ToLocalChecked(),
GetReferrer);
result->SetAccessor(
String::NewFromUtf8(isolate, "host", NewStringType::kInternalized)
.ToLocalChecked(),
GetHost);
result->SetAccessor(
String::NewFromUtf8(isolate, "userAgent", NewStringType::kInternalized)
.ToLocalChecked(),
GetUserAgent);
// Again, return the result through the current handle scope.
return handle_scope.Escape(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.
MaybeLocal<String> ReadFile(Isolate* isolate, const string& name) {
FILE* file = fopen(name.c_str(), "rb");
if (file == NULL) return MaybeLocal<String>();
fseek(file, 0, SEEK_END);
size_t size = ftell(file);
rewind(file);
std::unique_ptr<char> chars(new char[size + 1]);
chars.get()[size] = '\0';
for (size_t i = 0; i < size;) {
i += fread(&chars.get()[i], 1, size - i, file);
if (ferror(file)) {
fclose(file);
return MaybeLocal<String>();
}
}
fclose(file);
MaybeLocal<String> result = String::NewFromUtf8(
isolate, chars.get(), NewStringType::kNormal, static_cast<int>(size));
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(v8::Platform* platform, HttpRequestProcessor* processor,
int count, StringHttpRequest* reqs) {
for (int i = 0; i < count; i++) {
bool result = processor->Process(&reqs[i]);
while (v8::platform::PumpMessageLoop(platform, Isolate::GetCurrent()))
continue;
if (!result) 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[]) {
v8::V8::InitializeICUDefaultLocation(argv[0]);
v8::V8::InitializeExternalStartupData(argv[0]);
std::unique_ptr<v8::Platform> platform = v8::platform::NewDefaultPlatform();
v8::V8::InitializePlatform(platform.get());
v8::V8::Initialize();
map<string, string> options;
string file;
ParseOptions(argc, argv, &options, &file);
if (file.empty()) {
fprintf(stderr, "No script was specified.\n");
return 1;
}
Isolate::CreateParams create_params;
create_params.array_buffer_allocator =
v8::ArrayBuffer::Allocator::NewDefaultAllocator();
Isolate* isolate = Isolate::New(create_params);
Isolate::Scope isolate_scope(isolate);
HandleScope scope(isolate);
Local<String> source;
if (!ReadFile(isolate, file).ToLocal(&source)) {
fprintf(stderr, "Error reading '%s'.\n", file.c_str());
return 1;
}
JsHttpRequestProcessor processor(isolate, source);
map<string, string> output;
if (!processor.Initialize(&options, &output)) {
fprintf(stderr, "Error initializing processor.\n");
return 1;
}
if (!ProcessEntries(platform.get(), &processor, kSampleSize, kSampleRequests))
return 1;
PrintMap(&output);
}