Implement File API

src/FileSystemJsObject.cpp

Index: src/FileSystemJsObject.cpp
===================================================================
new file mode 100644
--- /dev/null
+++ b/src/FileSystemJsObject.cpp
@@ -0,0 +1,411 @@
+#include <AdblockPlus/FileSystem.h>
+#include <stdexcept>
+#include <sstream>
+#include <vector>
+
+#include "FileSystemJsObject.h"
+#include "Utils.h"
+#include "Thread.h"
+
+using namespace AdblockPlus;
+
+namespace
+{
+  class IoThread : public Thread
+  {
+  public:
+    IoThread(FileSystem& fileSystem, v8::Persistent<v8::Function> callback)
+      : isolate(v8::Isolate::GetCurrent()),
+        context(v8::Persistent<v8::Context>::New(isolate,
+                                                 v8::Context::GetCurrent())),
+        fileSystem(fileSystem), callback(callback)
+    {
+    }
+
+    virtual ~IoThread()
+    {
+      callback.Dispose(isolate);
+      context.Dispose(isolate);
+    }
+
+  protected:
+    v8::Isolate* const isolate;
+    v8::Persistent<v8::Context> context;
+    FileSystem& fileSystem;
+    v8::Persistent<v8::Function> callback;
+  };
+
+  class ReadThread : public IoThread
+  {
+  public:
+    ReadThread(FileSystem& fileSystem, v8::Persistent<v8::Function> callback,
+               const std::string& path)
+      : IoThread(fileSystem, callback), path(path)
+    {
+    }
+
+    void Run()
+    {
+      std::string content;
+      std::string error;
+      try
+      {
+        std::auto_ptr<std::istream> stream = fileSystem.Read(path);
+        content = Utils::Slurp(*stream);
+      }
+      catch (std::exception& e)
+      {
+        error = e.what();
+      }
+      catch (...)
+      {
+        error =  "Unknown error while reading from " + path;
+      }
+
+      const v8::Locker locker(isolate);
+      const v8::HandleScope handleScope;
+      const v8::Context::Scope contextScope(context);
+      v8::Handle<v8::Object> result = v8::Object::New();
+      result->Set(v8::String::New("content"), v8::String::New(content.c_str()));
+      result->Set(v8::String::New("error"), v8::String::New(error.c_str()));
+      callback->Call(callback, 1,
+                     reinterpret_cast<v8::Handle<v8::Value>*>(&result));
+      delete this;
+    }
+
+  private:
+    std::string path;
+  };
+
+  class WriteThread : public IoThread
+  {
+  public:
+    WriteThread(FileSystem& fileSystem, v8::Persistent<v8::Function> callback,
+                const std::string& path, const std::string& content)
+      : IoThread(fileSystem, callback), path(path), content(content)
+    {
+    }
+
+    void Run()
+    {
+      std::string error;
+      try
+      {
+        fileSystem.Write(path, content);
+      }
+      catch (std::exception& e)
+      {
+        error = e.what();
+      }
+      catch (...)
+      {
+        error = "Unknown error while writing to " + path;
+      }
+
+      const v8::Locker locker(isolate);
+      const v8::HandleScope handleScope;
+      const v8::Context::Scope contextScope(context);
+      v8::Handle<v8::Value> errorValue = v8::String::New(error.c_str());
+      callback->Call(callback, 1, &errorValue);
+      delete this;
+    }
+
+  private:
+    std::string path;
+    std::string content;
+  };
+
+  class MoveThread : public IoThread
+  {
+  public:
+    MoveThread(FileSystem& fileSystem, v8::Persistent<v8::Function> callback,
+               const std::string& fromPath, const std::string& toPath)
+      : IoThread(fileSystem, callback), fromPath(fromPath), toPath(toPath)
+    {
+    }
+
+    void Run()
+    {
+      std::string error;
+      try
+      {
+        fileSystem.Move(fromPath, toPath);
+      }
+      catch (std::exception& e)
+      {
+        error = e.what();
+      }
+      catch (...)
+      {
+        error = "Unknown error while moving " + fromPath + " to " + toPath;
+      }
+
+      const v8::Locker locker(isolate);
+      const v8::HandleScope handleScope;
+      const v8::Context::Scope contextScope(context);
+      v8::Handle<v8::Value> errorValue = v8::String::New(error.c_str());
+      callback->Call(callback, 1, &errorValue);
+      delete this;
+    }
+
+  private:
+    std::string fromPath;
+    std::string toPath;
+  };
+
+  class RemoveThread : public IoThread
+  {
+  public:
+    RemoveThread(FileSystem& fileSystem, v8::Persistent<v8::Function> callback,
+                 const std::string& path)
+      : IoThread(fileSystem, callback), path(path)
+    {
+    }
+
+    void Run()
+    {
+      std::string error;
+      try
+      {
+        fileSystem.Remove(path);
+      }
+      catch (std::exception& e)
+      {
+        error = e.what();
+      }
+      catch (...)
+      {
+        error = "Unknown error while removing " + path;
+      }
+
+      const v8::Locker locker(isolate);
+      const v8::HandleScope handleScope;
+      const v8::Context::Scope contextScope(context);
+      v8::Handle<v8::Value> errorValue = v8::String::New(error.c_str());
+      callback->Call(callback, 1, &errorValue);
+      delete this;
+    }
+
+  private:
+    std::string path;
+  };
+
+  class StatThread : public IoThread
+  {
+  public:
+    StatThread(FileSystem& fileSystem, v8::Persistent<v8::Function> callback,
+               const std::string& path)
+      : IoThread(fileSystem, callback), path(path)
+    {
+    }
+
+    void Run()
+    {
+      std::string error;
+      FileSystem::StatResult statResult;
+      try
+      {
+        statResult = fileSystem.Stat(path);
+      }
+      catch (std::exception& e)
+      {
+        error = e.what();
+      }
+      catch (...)
+      {
+        error = "Unknown error while calling stat on " + path;
+      }
+
+      const v8::Locker locker(isolate);
+      const v8::HandleScope handleScope;
+      const v8::Context::Scope contextScope(context);
+      v8::Handle<v8::Object> result = v8::Object::New();
+      result->Set(v8::String::New("exists"),
+                  v8::Boolean::New(statResult.exists));
+      result->Set(v8::String::New("isFile"),
+                  v8::Boolean::New(statResult.isFile));
+      result->Set(v8::String::New("isDirectory"),
+                  v8::Boolean::New(statResult.isDirectory));
+      result->Set(v8::String::New("lastModified"),
+                  v8::Number::New(statResult.lastModified));
+      result->Set(v8::String::New("error"), v8::String::New(error.c_str()));
+      callback->Call(callback, 1,
+                     reinterpret_cast<v8::Handle<v8::Value>*>(&result));
+      delete this;
+    }
+
+  private:
+    std::string path;
+  };
+
+  std::string CheckArguments(const v8::Arguments& arguments,
+                             const std::string& functionName,
+                             const std::vector<std::string> requiredTypes)
+  {
+    const int requiredCount = requiredTypes.size();
+    if (arguments.Length() != requiredCount)
+    {
+      std::stringstream stream;
+      stream << functionName << " requires " << requiredCount
+             << (requiredCount == 1 ? " parameter" : " parameters");
+      return stream.str();
+    }
+
+    for (int i = 0; i < requiredCount; i++)
+    {
+      const v8::Handle<v8::Value> argument = arguments[i];
+      const std::string requiredType = requiredTypes[i];
+      if ((requiredType == "string" && !argument->IsString())
+          || (requiredType == "number" && !argument->IsNumber())
+          || (requiredType == "function" && !argument->IsFunction()))
+      {
+        std::vector<std::string> countWords;
+        countWords.push_back("First");
+        countWords.push_back("Second");
+        countWords.push_back("Third");
+        std::stringstream stream;
+        if (i < countWords.size())
+          stream << countWords[i] << " argument";
+        else
+          stream << "Argument " << i;
+        stream << " to " << functionName << " must be a " << requiredType;
+        return stream.str();
+      }
+    }
+
+    return "";
+  }
+
+  v8::Handle<v8::Value> ReadCallback(const v8::Arguments& arguments)
+  {
+    std::vector<std::string> requiredTypes;
+    requiredTypes.push_back("string");
+    requiredTypes.push_back("function");
+    const std::string error = CheckArguments(arguments, "_fileSystem.read",
+                                             requiredTypes);
+    if (error.length())
+      return v8::ThrowException(v8::String::New(error.c_str()));
+
+    const v8::Handle<const v8::External> external =
+      v8::Handle<const v8::External>::Cast(arguments.Data());
+    FileSystem* const fileSystem = static_cast<FileSystem*>(external->Value());
+    const std::string path = *v8::String::Utf8Value(arguments[0]->ToString());
+    v8::Persistent<v8::Function> callback = v8::Persistent<v8::Function>::New(
+      v8::Isolate::GetCurrent(), v8::Handle<v8::Function>::Cast(arguments[1]));
+    ReadThread* const readThread = new ReadThread(*fileSystem, callback, path);
+    readThread->Start();
+    return v8::Undefined();
+  }
+
+  v8::Handle<v8::Value> WriteCallback(const v8::Arguments& arguments)
+  {
+    std::vector<std::string> requiredTypes;
+    requiredTypes.push_back("string");
+    requiredTypes.push_back("string");
+    requiredTypes.push_back("function");
+    const std::string error = CheckArguments(arguments, "_fileSystem.write",
+                                             requiredTypes);
+    if (error.length())
+      return v8::ThrowException(v8::String::New(error.c_str()));
+
+    const v8::Handle<const v8::External> external =
+      v8::Handle<const v8::External>::Cast(arguments.Data());
+    FileSystem* const fileSystem = static_cast<FileSystem*>(external->Value());
+    const std::string path = *v8::String::Utf8Value(arguments[0]->ToString());
+    const std::string content =
+      *v8::String::Utf8Value(arguments[1]->ToString());
+    v8::Persistent<v8::Function> callback = v8::Persistent<v8::Function>::New(
+      v8::Isolate::GetCurrent(), v8::Handle<v8::Function>::Cast(arguments[2]));
+    WriteThread* const writeThread = new WriteThread(*fileSystem, callback,
+                                                     path, content);
+    writeThread->Start();
+    return v8::Undefined();
+  }
+
+  v8::Handle<v8::Value> MoveCallback(const v8::Arguments& arguments)
+  {
+    std::vector<std::string> requiredTypes;
+    requiredTypes.push_back("string");
+    requiredTypes.push_back("string");
+    requiredTypes.push_back("function");
+    const std::string error = CheckArguments(arguments, "_fileSystem.move",
+                                             requiredTypes);
+    if (error.length())
+      return v8::ThrowException(v8::String::New(error.c_str()));
+
+    const v8::Handle<const v8::External> external =
+      v8::Handle<const v8::External>::Cast(arguments.Data());
+    FileSystem* const fileSystem = static_cast<FileSystem*>(external->Value());
+    const std::string fromPath =
+      *v8::String::Utf8Value(arguments[0]->ToString());
+    const std::string toPath = *v8::String::Utf8Value(arguments[1]->ToString());
+    v8::Persistent<v8::Function> callback = v8::Persistent<v8::Function>::New(
+      v8::Isolate::GetCurrent(), v8::Handle<v8::Function>::Cast(arguments[2]));
+    MoveThread* const moveThread = new MoveThread(*fileSystem, callback,
+                                                  fromPath, toPath);
+    moveThread->Start();
+    return v8::Undefined();
+  }
+
+  v8::Handle<v8::Value> RemoveCallback(const v8::Arguments& arguments)
+  {
+    std::vector<std::string> requiredTypes;
+    requiredTypes.push_back("string");
+    requiredTypes.push_back("function");
+    const std::string error = CheckArguments(arguments, "_fileSystem.remove",
+                                             requiredTypes);
+    if (error.length())
+      return v8::ThrowException(v8::String::New(error.c_str()));
+
+    const v8::Handle<const v8::External> external =
+      v8::Handle<const v8::External>::Cast(arguments.Data());
+    FileSystem* const fileSystem = static_cast<FileSystem*>(external->Value());
+    const std::string path = *v8::String::Utf8Value(arguments[0]->ToString());
+    v8::Persistent<v8::Function> callback = v8::Persistent<v8::Function>::New(
+      v8::Isolate::GetCurrent(), v8::Handle<v8::Function>::Cast(arguments[1]));
+    RemoveThread* const removeThread = new RemoveThread(*fileSystem, callback,
+                                                        path);
+    removeThread->Start();
+    return v8::Undefined();
+  }
+
+  v8::Handle<v8::Value> StatCallback(const v8::Arguments& arguments)
+  {
+    std::vector<std::string> requiredTypes;
+    requiredTypes.push_back("string");
+    requiredTypes.push_back("function");
+    const std::string error = CheckArguments(arguments, "_fileSystem.stat",
+                                             requiredTypes);
+    if (error.length())
+      return v8::ThrowException(v8::String::New(error.c_str()));
+
+    const v8::Handle<const v8::External> external =
+      v8::Handle<const v8::External>::Cast(arguments.Data());
+    FileSystem* const fileSystem = static_cast<FileSystem*>(external->Value());
+    const std::string path = *v8::String::Utf8Value(arguments[0]->ToString());
+    v8::Persistent<v8::Function> callback = v8::Persistent<v8::Function>::New(
+      v8::Isolate::GetCurrent(), v8::Handle<v8::Function>::Cast(arguments[1]));
+    StatThread* const statThread = new StatThread(*fileSystem, callback, path);
+    statThread->Start();
+    return v8::Undefined();
+  }
+}
+
+v8::Handle<v8::ObjectTemplate>
+FileSystemJsObject::Create(FileSystem& fileSystem)
+{
+  const v8::Locker locker(v8::Isolate::GetCurrent());
+  v8::HandleScope handleScope;
+  const v8::Handle<v8::ObjectTemplate> file = v8::ObjectTemplate::New();
+  file->Set(v8::String::New("read"),
+    v8::FunctionTemplate::New(ReadCallback, v8::External::New(&fileSystem)));
+  file->Set(v8::String::New("write"),
+    v8::FunctionTemplate::New(WriteCallback, v8::External::New(&fileSystem)));
+  file->Set(v8::String::New("move"),
+    v8::FunctionTemplate::New(MoveCallback, v8::External::New(&fileSystem)));
+  file->Set(v8::String::New("remove"),
+    v8::FunctionTemplate::New(RemoveCallback, v8::External::New(&fileSystem)));
+  file->Set(v8::String::New("stat"),
+    v8::FunctionTemplate::New(StatCallback, v8::External::New(&fileSystem)));
+  return handleScope.Close(file);
+}