ProcessManager: Add a new per-proces "open files" view showing open FDs

This uses the data from /proc/PID/fds with ease now that it's JSON. :^)

Applications/ProcessManager/Makefile

@@ -8,6 +8,8 @@ OBJS = \
     ProcessStacksWidget.o \
     ProcessMemoryMapWidget.o \
     ProcessMemoryMapModel.o \
+    ProcessFileDescriptorMapWidget.o \
+    ProcessFileDescriptorMapModel.o \
     main.o
 
 APP = ProcessManager

Applications/ProcessManager/ProcessFileDescriptorMapModel.cpp

@@ -0,0 +1,74 @@
+#include "ProcessFileDescriptorMapModel.h"
+#include <AK/JsonObject.h>
+#include <AK/StringBuilder.h>
+#include <LibCore/CFile.h>
+
+void ProcessFileDescriptorMapModel::update()
+{
+    CFile file(String::format("/proc/%d/fds", m_pid));
+    if (!file.open(CIODevice::ReadOnly)) {
+        dbg() << "Unable to open " << file.filename();
+        return;
+    }
+
+    auto json = JsonValue::from_string(file.read_all());
+
+    ASSERT(json.is_array());
+    m_process_fds = json.as_array();
+
+    did_update();
+}
+
+int ProcessFileDescriptorMapModel::row_count(const GModelIndex&) const
+{
+    return m_process_fds.size();
+}
+
+String ProcessFileDescriptorMapModel::column_name(int column) const
+{
+    switch (column) {
+    case Column::FileDescriptor:
+        return "FD";
+    case Column::Path:
+        return "Path";
+    default:
+        ASSERT_NOT_REACHED();
+    }
+}
+
+GModel::ColumnMetadata ProcessFileDescriptorMapModel::column_metadata(int column) const
+{
+    switch (column) {
+    case Column::FileDescriptor:
+        return { 32, TextAlignment::CenterRight };
+    case Column::Path:
+        return { 300, TextAlignment::CenterLeft };
+    default:
+        ASSERT_NOT_REACHED();
+    }
+    return {};
+}
+
+GVariant ProcessFileDescriptorMapModel::data(const GModelIndex& index, Role role) const
+{
+    auto& fd_object = m_process_fds.at(index.row()).as_object();
+    if (role == GModel::Role::Display) {
+        switch (index.column()) {
+        case Column::FileDescriptor:
+            return fd_object.get("fd").to_int();
+        case Column::Path:
+            return fd_object.get("absolute_path").to_string();
+        default:
+            ASSERT_NOT_REACHED();
+        }
+    }
+    return {};
+}
+
+void ProcessFileDescriptorMapModel::set_pid(pid_t pid)
+{
+    if (m_pid == pid)
+        return;
+    m_pid = pid;
+    update();
+}

Applications/ProcessManager/ProcessFileDescriptorMapModel.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <AK/JsonArray.h>
+#include <LibGUI/GModel.h>
+
+class ProcessFileDescriptorMapModel final : public GModel {
+public:
+    enum Column {
+        FileDescriptor,
+        Path,
+        __Count
+    };
+
+    ProcessFileDescriptorMapModel() {}
+    virtual ~ProcessFileDescriptorMapModel() override {}
+
+    virtual int row_count(const GModelIndex& = GModelIndex()) const override;
+    virtual int column_count(const GModelIndex& = GModelIndex()) const override { return Column::__Count; }
+    virtual String column_name(int) const override;
+    virtual ColumnMetadata column_metadata(int) const override;
+    virtual GVariant data(const GModelIndex&, Role = Role::Display) const override;
+    virtual void update() override;
+
+    void set_pid(pid_t);
+
+private:
+    JsonArray m_process_fds;
+    int m_pid { -1 };
+};

Applications/ProcessManager/ProcessFileDescriptorMapWidget.cpp

@@ -0,0 +1,25 @@
+#include "ProcessFileDescriptorMapWidget.h"
+#include "ProcessFileDescriptorMapModel.h"
+#include <LibGUI/GBoxLayout.h>
+#include <LibGUI/GTableView.h>
+
+ProcessFileDescriptorMapWidget::ProcessFileDescriptorMapWidget(GWidget* parent)
+    : GWidget(parent)
+{
+    set_layout(make<GBoxLayout>(Orientation::Vertical));
+    layout()->set_margins({ 4, 4, 4, 4 });
+    m_table_view = new GTableView(this);
+    m_table_view->set_model(adopt(*new ProcessFileDescriptorMapModel));
+}
+
+ProcessFileDescriptorMapWidget::~ProcessFileDescriptorMapWidget()
+{
+}
+
+void ProcessFileDescriptorMapWidget::set_pid(pid_t pid)
+{
+    if (m_pid == pid)
+        return;
+    m_pid = pid;
+    static_cast<ProcessFileDescriptorMapModel*>(m_table_view->model())->set_pid(pid);
+}

Applications/ProcessManager/ProcessFileDescriptorMapWidget.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include <LibGUI/GWidget.h>
+
+class GTableView;
+
+class ProcessFileDescriptorMapWidget final : public GWidget {
+    C_OBJECT(ProcessFileDescriptorMapWidget);
+public:
+    explicit ProcessFileDescriptorMapWidget(GWidget* parent);
+    virtual ~ProcessFileDescriptorMapWidget() override;
+
+    void set_pid(pid_t);
+
+private:
+    GTableView* m_table_view { nullptr };
+    pid_t m_pid { -1 };
+};

Applications/ProcessManager/main.cpp

@@ -1,5 +1,6 @@
 #include "GraphWidget.h"
 #include "MemoryStatsWidget.h"
+#include "ProcessFileDescriptorMapWidget.h"
 #include "ProcessMemoryMapWidget.h"
 #include "ProcessStacksWidget.h"
 #include "ProcessTableView.h"
@@ -157,6 +158,9 @@ int main(int argc, char** argv)
 
     auto* process_tab_widget = new GTabWidget(process_container_splitter);
 
+    auto* open_files_widget = new ProcessFileDescriptorMapWidget(nullptr);
+    process_tab_widget->add_widget("Open files", open_files_widget);
+
     auto* memory_map_widget = new ProcessMemoryMapWidget(nullptr);
     process_tab_widget->add_widget("Memory map", memory_map_widget);
 
@@ -164,6 +168,7 @@ int main(int argc, char** argv)
     process_tab_widget->add_widget("Stacks", stacks_widget);
 
     process_table_view->on_process_selected = [&](pid_t pid) {
+        open_files_widget->set_pid(pid);
         stacks_widget->set_pid(pid);
         memory_map_widget->set_pid(pid);
     };