LibCore: Use `Core::Stream` for `ProcessStatisticsReader`

Userland/Applications/SystemMonitor/ProcessModel.cpp

@@ -433,16 +433,16 @@ void ProcessModel::update()
 
     HashTable<int> live_tids;
     u64 total_time_scheduled_diff = 0;
-    if (all_processes.has_value()) {
+    if (!all_processes.is_error()) {
         if (m_has_total_scheduled_time)
-            total_time_scheduled_diff = all_processes->total_time_scheduled - m_total_time_scheduled;
+            total_time_scheduled_diff = all_processes.value().total_time_scheduled - m_total_time_scheduled;
 
-        m_total_time_scheduled = all_processes->total_time_scheduled;
-        m_total_time_scheduled_kernel = all_processes->total_time_scheduled_kernel;
+        m_total_time_scheduled = all_processes.value().total_time_scheduled;
+        m_total_time_scheduled_kernel = all_processes.value().total_time_scheduled_kernel;
         m_has_total_scheduled_time = true;
 
-        for (size_t i = 0; i < all_processes->processes.size(); ++i) {
-            auto const& process = all_processes->processes[i];
+        for (size_t i = 0; i < all_processes.value().processes.size(); ++i) {
+            auto const& process = all_processes.value().processes[i];
             NonnullOwnPtr<Process>* process_state = nullptr;
             for (size_t i = 0; i < m_processes.size(); ++i) {
                 auto* other_process = &m_processes.ptr_at(i);
@@ -549,7 +549,7 @@ void ProcessModel::update()
         on_cpu_info_change(m_cpus);
 
     if (on_state_update)
-        on_state_update(all_processes.has_value() ? all_processes->processes.size() : 0, m_threads.size());
+        on_state_update(!all_processes.is_error() ? all_processes.value().processes.size() : 0, m_threads.size());
 
     // FIXME: This is a rather hackish way of invalidating indices.
     //        It would be good if GUI::Model had a way to orchestrate removal/insertion while preserving indices.

Userland/Demos/CatDog/CatDog.cpp

@@ -12,8 +12,8 @@
 
 void CatDog::timer_event(Core::TimerEvent&)
 {
-    auto maybe_proc_info = Core::ProcessStatisticsReader::get_all(m_proc_all);
-    if (maybe_proc_info.has_value()) {
+    auto maybe_proc_info = Core::ProcessStatisticsReader::get_all(*m_proc_all);
+    if (!maybe_proc_info.is_error()) {
         auto proc_info = maybe_proc_info.release_value();
 
         auto maybe_paint_program = proc_info.processes.first_matching([](auto& process) {

Userland/Demos/CatDog/CatDog.h

@@ -11,6 +11,7 @@
 #include <AK/RefPtr.h>
 #include <LibCore/ElapsedTimer.h>
 #include <LibCore/File.h>
+#include <LibCore/Stream.h>
 #include <LibGUI/Menu.h>
 #include <LibGUI/MouseTracker.h>
 #include <LibGUI/Widget.h>
@@ -72,7 +73,7 @@ private:
     bool m_up, m_down, m_left, m_right;
     bool m_roaming { true };
 
-    RefPtr<Core::File> m_proc_all;
+    NonnullOwnPtr<Core::Stream::File> m_proc_all;
 
     NonnullRefPtr<Gfx::Bitmap> m_alert = *Gfx::Bitmap::try_load_from_file("/res/icons/catdog/alert.png"sv).release_value_but_fixme_should_propagate_errors();
     NonnullRefPtr<Gfx::Bitmap> m_artist = *Gfx::Bitmap::try_load_from_file("/res/icons/catdog/artist.png"sv).release_value_but_fixme_should_propagate_errors();
@@ -126,7 +127,7 @@ private:
 
     CatDog()
         : m_temp_pos { 0, 0 }
-        , m_proc_all(MUST(Core::File::open("/sys/kernel/processes", Core::OpenMode::ReadOnly)))
+        , m_proc_all(MUST(Core::Stream::File::open("/sys/kernel/processes"sv, Core::Stream::OpenMode::Read)))
     {
         set_image_by_main_state();
     }

Userland/DevTools/Profiler/main.cpp

@@ -352,8 +352,8 @@ bool generate_profile(pid_t& pid)
     DeprecatedString process_name;
 
     auto all_processes = Core::ProcessStatisticsReader::get_all();
-    if (all_processes.has_value()) {
-        auto& processes = all_processes->processes;
+    if (!all_processes.is_error()) {
+        auto& processes = all_processes.value().processes;
         if (auto it = processes.find_if([&](auto& entry) { return entry.pid == pid; }); it != processes.end())
             process_name = it->name;
         else

Userland/Libraries/LibCore/ProcessStatisticsReader.cpp

@@ -8,7 +8,6 @@
 #include <AK/JsonArray.h>
 #include <AK/JsonObject.h>
 #include <AK/JsonValue.h>
-#include <LibCore/File.h>
 #include <LibCore/ProcessStatisticsReader.h>
 #include <pwd.h>
 
@@ -16,29 +15,14 @@ namespace Core {
 
 HashMap<uid_t, DeprecatedString> ProcessStatisticsReader::s_usernames;
 
-Optional<AllProcessesStatistics> ProcessStatisticsReader::get_all(RefPtr<Core::File>& proc_all_file, bool include_usernames)
+ErrorOr<AllProcessesStatistics> ProcessStatisticsReader::get_all(Core::Stream::SeekableStream& proc_all_file, bool include_usernames)
 {
-    if (proc_all_file) {
-        if (!proc_all_file->seek(0, Core::SeekMode::SetPosition)) {
-            warnln("ProcessStatisticsReader: Failed to refresh /sys/kernel/processes: {}", proc_all_file->error_string());
-            return {};
-        }
-    } else {
-        proc_all_file = Core::File::construct("/sys/kernel/processes");
-        if (!proc_all_file->open(Core::OpenMode::ReadOnly)) {
-            warnln("ProcessStatisticsReader: Failed to open /sys/kernel/processes: {}", proc_all_file->error_string());
-            return {};
-        }
-    }
+    TRY(proc_all_file.seek(0, Core::Stream::SeekMode::SetPosition));
 
     AllProcessesStatistics all_processes_statistics;
 
-    auto file_contents = proc_all_file->read_all();
-    auto json = JsonValue::from_string(file_contents);
-    if (json.is_error())
-        return {};
-
-    auto& json_obj = json.value().as_object();
+    auto file_contents = TRY(proc_all_file.read_all());
+    auto json_obj = TRY(JsonValue::from_string(file_contents)).as_object();
     json_obj.get("processes"sv).as_array().for_each([&](auto& value) {
         const JsonObject& process_object = value.as_object();
         Core::ProcessStatistics process;
@@ -104,10 +88,10 @@ Optional<AllProcessesStatistics> ProcessStatisticsReader::get_all(RefPtr<Core::F
     return all_processes_statistics;
 }
 
-Optional<AllProcessesStatistics> ProcessStatisticsReader::get_all(bool include_usernames)
+ErrorOr<AllProcessesStatistics> ProcessStatisticsReader::get_all(bool include_usernames)
 {
-    RefPtr<Core::File> proc_all_file;
-    return get_all(proc_all_file, include_usernames);
+    auto proc_all_file = TRY(Core::Stream::File::open("/sys/kernel/processes"sv, Core::Stream::OpenMode::Read));
+    return get_all(*proc_all_file, include_usernames);
 }
 
 DeprecatedString ProcessStatisticsReader::username_from_uid(uid_t uid)

Userland/Libraries/LibCore/ProcessStatisticsReader.h

@@ -7,7 +7,7 @@
 #pragma once
 
 #include <AK/DeprecatedString.h>
-#include <LibCore/File.h>
+#include <LibCore/Stream.h>
 #include <unistd.h>
 
 namespace Core {
@@ -72,8 +72,8 @@ struct AllProcessesStatistics {
 
 class ProcessStatisticsReader {
 public:
-    static Optional<AllProcessesStatistics> get_all(RefPtr<Core::File>&, bool include_usernames = true);
-    static Optional<AllProcessesStatistics> get_all(bool include_usernames = true);
+    static ErrorOr<AllProcessesStatistics> get_all(Core::Stream::SeekableStream&, bool include_usernames = true);
+    static ErrorOr<AllProcessesStatistics> get_all(bool include_usernames = true);
 
 private:
     static DeprecatedString username_from_uid(uid_t);

Userland/Libraries/LibCore/SessionManagement.cpp

@@ -22,14 +22,12 @@ static ErrorOr<Core::ProcessStatistics const*> get_proc(Core::AllProcessesStatis
 
 ErrorOr<pid_t> root_session_id(Optional<pid_t> force_sid)
 {
-    auto stats = Core::ProcessStatisticsReader::get_all(false);
-    if (!stats.has_value())
-        return Error::from_string_literal("Failed to get all process statistics");
+    auto stats = TRY(Core::ProcessStatisticsReader::get_all(false));
 
     pid_t sid = (force_sid.has_value()) ? force_sid.value() : TRY(System::getsid());
     while (true) {
-        pid_t parent = TRY(get_proc(stats.value(), sid))->ppid;
-        pid_t parent_sid = TRY(get_proc(stats.value(), parent))->sid;
+        pid_t parent = TRY(get_proc(stats, sid))->ppid;
+        pid_t parent_sid = TRY(get_proc(stats, parent))->sid;
 
         if (parent_sid == 0)
             break;

Userland/Libraries/LibGUI/RunningProcessesModel.cpp

@@ -21,7 +21,7 @@ void RunningProcessesModel::update()
     m_processes.clear();
 
     auto all_processes = Core::ProcessStatisticsReader::get_all();
-    if (all_processes.has_value()) {
+    if (!all_processes.is_error()) {
         for (auto& it : all_processes.value().processes) {
             Process process;
             process.pid = it.pid;

Userland/Services/WindowServer/Window.cpp

@@ -1073,15 +1073,13 @@ ErrorOr<Optional<DeprecatedString>> Window::compute_title_username(ConnectionFro
 {
     if (!client)
         return Error::from_string_literal("Tried to compute title username without a client");
-    auto stats = Core::ProcessStatisticsReader::get_all(true);
-    if (!stats.has_value())
-        return Error::from_string_literal("Failed to get all process statistics");
+    auto stats = TRY(Core::ProcessStatisticsReader::get_all(true));
     pid_t client_pid = TRY(client->socket().peer_pid());
-    auto client_stat = stats.value().processes.first_matching([&](auto& stat) { return stat.pid == client_pid; });
+    auto client_stat = stats.processes.first_matching([&](auto& stat) { return stat.pid == client_pid; });
     if (!client_stat.has_value())
         return Error::from_string_literal("Failed to find client process stat");
     pid_t login_session_pid = TRY(Core::SessionManagement::root_session_id(client_pid));
-    auto login_session_stat = stats.value().processes.first_matching([&](auto& stat) { return stat.pid == login_session_pid; });
+    auto login_session_stat = stats.processes.first_matching([&](auto& stat) { return stat.pid == login_session_pid; });
     if (!login_session_stat.has_value())
         return Error::from_string_literal("Failed to find login process stat");
     if (login_session_stat.value().uid == client_stat.value().uid)

Userland/Utilities/killall.cpp

@@ -21,11 +21,9 @@ static void print_usage_and_exit()
 
 static ErrorOr<int> kill_all(DeprecatedString const& process_name, unsigned const signum)
 {
-    auto all_processes = Core::ProcessStatisticsReader::get_all();
-    if (!all_processes.has_value())
-        return 1;
+    auto all_processes = TRY(Core::ProcessStatisticsReader::get_all());
 
-    for (auto& process : all_processes.value().processes) {
+    for (auto& process : all_processes.processes) {
         if (process.name == process_name) {
             TRY(Core::System::kill(process.pid, signum));
         }

Userland/Utilities/lsof.cpp

@@ -141,11 +141,9 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
     }
 
     outln("{:28} {:>4} {:>4} {:10} {:>4} {}", "COMMAND", "PID", "PGID", "USER", "FD", "NAME");
-    auto all_processes = Core::ProcessStatisticsReader::get_all();
-    if (!all_processes.has_value())
-        return 1;
+    auto all_processes = TRY(Core::ProcessStatisticsReader::get_all());
     if (arg_pid == -1) {
-        for (auto& process : all_processes.value().processes) {
+        for (auto& process : all_processes.processes) {
             if (process.pid == 0)
                 continue;
             auto open_files = get_open_files_by_pid(process.pid);
@@ -170,7 +168,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
             return 0;
 
         for (auto& file : open_files) {
-            display_entry(file, *all_processes->processes.find_if([&](auto& entry) { return entry.pid == arg_pid; }));
+            display_entry(file, *all_processes.processes.find_if([&](auto& entry) { return entry.pid == arg_pid; }));
         }
     }
 

Userland/Utilities/netstat.cpp

@@ -58,11 +58,9 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
     HashMap<pid_t, DeprecatedString> programs;
 
     if (flag_program) {
-        auto processes = Core::ProcessStatisticsReader::get_all();
-        if (!processes.has_value())
-            return 1;
+        auto processes = TRY(Core::ProcessStatisticsReader::get_all());
 
-        for (auto& proc : processes.value().processes) {
+        for (auto& proc : processes.processes) {
             programs.set(proc.pid, proc.name);
         }
     }

Userland/Utilities/pgrep.cpp

@@ -38,12 +38,10 @@ ErrorOr<int> serenity_main(Main::Arguments args)
         return 1;
     }
 
-    auto all_processes = Core::ProcessStatisticsReader::get_all();
-    if (!all_processes.has_value())
-        return 1;
+    auto all_processes = TRY(Core::ProcessStatisticsReader::get_all());
 
     Vector<pid_t> matches;
-    for (auto& it : all_processes.value().processes) {
+    for (auto& it : all_processes.processes) {
         auto result = re.match(it.name, PosixFlags::Global);
         if (result.success ^ invert_match) {
             matches.append(it.pid);

Userland/Utilities/pidof.cpp

@@ -18,11 +18,9 @@ static ErrorOr<int> pid_of(DeprecatedString const& process_name, bool single_sho
 {
     bool displayed_at_least_one = false;
 
-    auto all_processes = Core::ProcessStatisticsReader::get_all();
-    if (!all_processes.has_value())
-        return 1;
+    auto all_processes = TRY(Core::ProcessStatisticsReader::get_all());
 
-    for (auto& it : all_processes.value().processes) {
+    for (auto& it : all_processes.processes) {
         if (it.name == process_name) {
             if (!omit_pid || it.pid != pid) {
                 out(displayed_at_least_one ? " {}"sv : "{}"sv, it.pid);

Userland/Utilities/pkill.cpp

@@ -34,10 +34,7 @@ ErrorOr<int> serenity_main(Main::Arguments args)
     args_parser.add_positional_argument(pattern, "Process name to search for", "process-name");
     args_parser.parse(args);
 
-    auto all_processes = Core::ProcessStatisticsReader::get_all();
-    if (!all_processes.has_value()) {
-        return 1;
-    }
+    auto all_processes = TRY(Core::ProcessStatisticsReader::get_all());
 
     PosixOptions options {};
     if (case_insensitive) {
@@ -50,7 +47,7 @@ ErrorOr<int> serenity_main(Main::Arguments args)
     }
 
     Vector<Core::ProcessStatistics> matched_processes;
-    for (auto& process : all_processes.value().processes) {
+    for (auto& process : all_processes.processes) {
         auto result = re.match(process.name, PosixFlags::Global);
         if (result.success) {
             matched_processes.append(process);

Userland/Utilities/ps.cpp

@@ -98,11 +98,9 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
         cmd_column = add_column("CMD", Alignment::Left);
     }
 
-    auto all_processes = Core::ProcessStatisticsReader::get_all();
-    if (!all_processes.has_value())
-        return 1;
+    auto all_processes = TRY(Core::ProcessStatisticsReader::get_all());
 
-    auto& processes = all_processes.value().processes;
+    auto& processes = all_processes.processes;
 
     if (!pid_list.is_empty()) {
         every_process_flag = true;

Userland/Utilities/top.cpp

@@ -89,14 +89,12 @@ struct Snapshot {
     u64 total_time_scheduled_kernel { 0 };
 };
 
-static Snapshot get_snapshot()
+static ErrorOr<Snapshot> get_snapshot()
 {
-    auto all_processes = Core::ProcessStatisticsReader::get_all();
-    if (!all_processes.has_value())
-        return {};
+    auto all_processes = TRY(Core::ProcessStatisticsReader::get_all());
 
     Snapshot snapshot;
-    for (auto& process : all_processes.value().processes) {
+    for (auto& process : all_processes.processes) {
         for (auto& thread : process.threads) {
             ThreadData thread_data;
             thread_data.tid = thread.tid;
@@ -126,8 +124,8 @@ static Snapshot get_snapshot()
         }
     }
 
-    snapshot.total_time_scheduled = all_processes->total_time_scheduled;
-    snapshot.total_time_scheduled_kernel = all_processes->total_time_scheduled_kernel;
+    snapshot.total_time_scheduled = all_processes.total_time_scheduled;
+    snapshot.total_time_scheduled_kernel = all_processes.total_time_scheduled_kernel;
 
     return snapshot;
 }
@@ -216,7 +214,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
     enable_nonblocking_stdin();
 
     Vector<ThreadData*> threads;
-    auto prev = get_snapshot();
+    auto prev = TRY(get_snapshot());
     usleep(10000);
     for (;;) {
         if (g_window_size_changed) {
@@ -224,7 +222,7 @@ ErrorOr<int> serenity_main(Main::Arguments arguments)
             g_window_size_changed = false;
         }
 
-        auto current = get_snapshot();
+        auto current = TRY(get_snapshot());
         auto total_scheduled_diff = current.total_time_scheduled - prev.total_time_scheduled;
 
         printf("\033[3J\033[H\033[2J");

Userland/Utilities/w.cpp

@@ -33,11 +33,7 @@ ErrorOr<int> serenity_main(Main::Arguments)
         return 1;
     }
 
-    auto process_statistics = Core::ProcessStatisticsReader::get_all();
-    if (!process_statistics.has_value()) {
-        warnln("Error: Could not get process statistics");
-        return 1;
-    }
+    auto process_statistics = TRY(Core::ProcessStatisticsReader::get_all());
 
     auto now = time(nullptr);
 
@@ -70,7 +66,7 @@ ErrorOr<int> serenity_main(Main::Arguments)
 
         DeprecatedString what = "n/a";
 
-        for (auto& process : process_statistics.value().processes) {
+        for (auto& process : process_statistics.processes) {
             if (process.tty == tty && process.pid == process.pgid)
                 what = process.name;
         }