Browser+LibWeb+WebContent: Allow Browser to load local files

To achieve this goal:
 - The Browser unveils "/tmp/portal/filesystemaccess"
 - Pass the page through LoadRequest => ResourceLoader
 - ResourceLoader requests a file to the FileSystemAccessServer via IPC
 - OutOfProcessWebView handles it and sends a file descriptor back to
 the Page.

Userland/Libraries/LibWeb/CMakeLists.txt

@@ -274,6 +274,7 @@ set(SOURCES
     Layout/TextNode.cpp
     Layout/TreeBuilder.cpp
     Loader/ContentFilter.cpp
+    Loader/FileRequest.cpp
     Loader/FrameLoader.cpp
     Loader/ImageLoader.cpp
     Loader/ImageResource.cpp

Userland/Libraries/LibWeb/Loader/FileRequest.cpp

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2022, Lucas Chollet <lucas.chollet@free.fr>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "FileRequest.h"
+
+namespace Web {
+
+FileRequest::FileRequest(String path)
+    : m_path(move(path))
+{
+}
+
+String FileRequest::path() const
+{
+    return m_path;
+}
+
+}

Userland/Libraries/LibWeb/Loader/FileRequest.h

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2022, Lucas Chollet <lucas.chollet@free.fr>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Error.h>
+#include <AK/Function.h>
+#include <AK/RefCounted.h>
+#include <AK/String.h>
+
+namespace Web {
+
+class FileRequest : public RefCounted<FileRequest> {
+public:
+    explicit FileRequest(String path);
+
+    String path() const;
+
+    Function<void(ErrorOr<i32>)> on_file_request_finish;
+
+private:
+    String m_path {};
+};
+
+}

Userland/Libraries/LibWeb/Loader/LoadRequest.cpp

@@ -19,6 +19,7 @@ LoadRequest LoadRequest::create_for_url_on_page(const AK::URL& url, Page* page)
         String cookie = page->client().page_did_request_cookie(url, Cookie::Source::Http);
         if (!cookie.is_empty())
             request.set_header("Cookie", cookie);
+        request.set_page(*page);
     }
 
     return request;

Userland/Libraries/LibWeb/Loader/LoadRequest.h

@@ -12,6 +12,7 @@
 #include <AK/URL.h>
 #include <LibCore/ElapsedTimer.h>
 #include <LibWeb/Forward.h>
+#include <LibWeb/Page/Page.h>
 
 namespace Web {
 
@@ -37,6 +38,9 @@ public:
     void start_timer() { m_load_timer.start(); };
     Time load_time() const { return m_load_timer.elapsed_time(); }
 
+    Optional<Page&>& page() { return m_page; };
+    void set_page(Page& page) { m_page = page; }
+
     unsigned hash() const
     {
         auto body_hash = string_hash((char const*)m_body.data(), m_body.size());
@@ -70,6 +74,7 @@ private:
     HashMap<String, String> m_headers;
     ByteBuffer m_body;
     Core::ElapsedTimer m_load_timer;
+    Optional<Page&> m_page;
 };
 
 }

Userland/Libraries/LibWeb/Loader/ResourceLoader.cpp

@@ -213,21 +213,51 @@ void ResourceLoader::load(LoadRequest& request, Function<void(ReadonlyBytes, Has
     }
 
     if (url.protocol() == "file") {
-        auto file_result = Core::File::open(url.path(), Core::OpenMode::ReadOnly);
-        if (file_result.is_error()) {
-            auto& error = file_result.error();
-            log_failure(request, error);
-            if (error_callback)
-                error_callback(String::formatted("{}", error), error.code());
-            return;
-        }
+        if (request.page().has_value())
+            m_page = request.page().value();
 
-        auto file = file_result.release_value();
-        auto data = file->read_all();
-        log_success(request);
-        deferred_invoke([data = move(data), success_callback = move(success_callback)] {
+        VERIFY(m_page.has_value());
+        auto file_ref = make_ref_counted<FileRequest>(url.path());
+        file_ref->on_file_request_finish = [this, success_callback = move(success_callback), error_callback = move(error_callback), log_success, log_failure, request, file_ref](ErrorOr<i32> file_or_error) {
+            --m_pending_loads;
+            if (on_load_counter_change)
+                on_load_counter_change();
+
+            if (file_or_error.is_error()) {
+                log_failure(request, file_or_error.error());
+                if (error_callback)
+                    error_callback(String::formatted("{}", file_or_error.error()), file_or_error.error().code());
+                return;
+            }
+
+            auto const fd = file_or_error.value();
+
+            auto maybe_file = Core::Stream::File::adopt_fd(fd, Core::Stream::OpenMode::Read);
+            if (maybe_file.is_error()) {
+                log_failure(request, maybe_file.error());
+                if (error_callback)
+                    error_callback(String::formatted("{}", maybe_file.error()), maybe_file.error().code());
+                return;
+            }
+
+            auto file = maybe_file.release_value();
+            auto maybe_data = file->read_all();
+            if (maybe_data.is_error()) {
+                log_failure(request, maybe_data.error());
+                if (error_callback)
+                    error_callback(String::formatted("{}", maybe_data.error()), maybe_data.error().code());
+                return;
+            }
+            auto data = maybe_data.release_value();
+            log_success(request);
             success_callback(data, {}, {});
-        });
+        };
+        m_page->client().request_file(file_ref);
+
+        ++m_pending_loads;
+        if (on_load_counter_change)
+            on_load_counter_change();
+
         return;
     }
 

Userland/Libraries/LibWeb/Loader/ResourceLoader.h

@@ -14,6 +14,7 @@
 #include <LibCore/Object.h>
 #include <LibCore/Proxy.h>
 #include <LibWeb/Loader/Resource.h>
+#include <LibWeb/Page/Page.h>
 
 namespace Web {
 
@@ -98,6 +99,7 @@ private:
     HashTable<NonnullRefPtr<ResourceLoaderConnectorRequest>> m_active_requests;
     NonnullRefPtr<ResourceLoaderConnector> m_connector;
     String m_user_agent;
+    Optional<Page&> m_page {};
 };
 
 }

Userland/Libraries/LibWeb/Page/Page.h

@@ -18,6 +18,7 @@
 #include <LibGfx/StandardCursor.h>
 #include <LibWeb/CSS/PreferredColorScheme.h>
 #include <LibWeb/Forward.h>
+#include <LibWeb/Loader/FileRequest.h>
 
 namespace Web {
 
@@ -111,6 +112,8 @@ public:
     virtual void page_did_set_cookie(const AK::URL&, Cookie::ParsedCookie const&, Cookie::Source) { }
     virtual void page_did_update_resource_count(i32) { }
 
+    virtual void request_file(NonnullRefPtr<FileRequest>&) = 0;
+
 protected:
     virtual ~PageClient() = default;
 };