Userland+LibCore: Use CProcessStatisticsReader to implement top.

Also tweaked CProcessStatisticsReader a bit to simplify the API.

Libraries/LibCore/CProcessStatisticsReader.cpp

@@ -6,27 +6,16 @@
 #include <pwd.h>
 #include <stdio.h>
 
-CProcessStatisticsReader::CProcessStatisticsReader()
-{
-    setpwent();
-    while (auto* passwd = getpwent())
-        m_usernames.set(passwd->pw_uid, passwd->pw_name);
-    endpwent();
-}
+HashMap<uid_t, String> CProcessStatisticsReader::s_usernames;
 
-HashMap<pid_t, CProcessStatistics> CProcessStatisticsReader::get_map()
+HashMap<pid_t, CProcessStatistics> CProcessStatisticsReader::get_all()
 {
-    HashMap<pid_t, CProcessStatistics> res;
-    update_map(res);
-    return res;
-}
+    HashMap<pid_t, CProcessStatistics> map;
 
-void CProcessStatisticsReader::update_map(HashMap<pid_t, CProcessStatistics>& map)
-{
     CFile file("/proc/all");
     if (!file.open(CIODevice::ReadOnly)) {
         fprintf(stderr, "CProcessHelper : failed to open /proc/all: %s\n", file.error_string());
-        return;
+        return {};
     }
 
     auto file_contents = file.read_all();
@@ -37,7 +26,7 @@ void CProcessStatisticsReader::update_map(HashMap<pid_t, CProcessStatistics>& ma
         process.pid = process_object.get("pid").to_u32();
         process.nsched = process_object.get("times_scheduled").to_u32();
         process.uid = process_object.get("uid").to_u32();
-        process.username = get_username_from_uid(process.uid);
+        process.username = username_from_uid(process.uid);
         process.priority = process_object.get("priority").to_string();
         process.syscalls = process_object.get("syscall_count").to_u32();
         process.state = process_object.get("state").to_string();
@@ -46,13 +35,22 @@ void CProcessStatisticsReader::update_map(HashMap<pid_t, CProcessStatistics>& ma
         process.physical_size = process_object.get("amount_resident").to_u32();
         map.set(process.pid, process);
     });
+
+    return map;
 }
 
-String CProcessStatisticsReader::get_username_from_uid(const uid_t uid)
+String CProcessStatisticsReader::username_from_uid(uid_t uid)
 {
-    auto it = m_usernames.find(uid);
-    if (it != m_usernames.end())
+    if (s_usernames.is_empty()) {
+        setpwent();
+        while (auto* passwd = getpwent())
+            s_usernames.set(passwd->pw_uid, passwd->pw_name);
+        endpwent();
+    }
+
+    auto it = s_usernames.find(uid);
+    if (it != s_usernames.end())
         return (*it).value;
-    else
-        return String::number(uid);
+    return String::number(uid);
 }
+

Libraries/LibCore/CProcessStatisticsReader.h

@@ -18,12 +18,9 @@ struct CProcessStatistics {
 
 class CProcessStatisticsReader {
 public:
-    CProcessStatisticsReader();
-    HashMap<pid_t, CProcessStatistics> get_map();
+    static HashMap<pid_t, CProcessStatistics> get_all();
 
 private:
-    void update_map(HashMap<pid_t, CProcessStatistics>& map);
-    String get_username_from_uid(const uid_t uid);
-
-    HashMap<uid_t, String> m_usernames;
+    static String username_from_uid(uid_t);
+    static HashMap<uid_t, String> s_usernames;
 };

Userland/killall.cpp

@@ -13,7 +13,7 @@ static void print_usage_and_exit()
 
 static int kill_all(const String& process_name, const unsigned signum)
 {
-    HashMap<pid_t, CProcessStatistics> processes = CProcessStatisticsReader().get_map();
+    auto processes = CProcessStatisticsReader().get_all();
 
     for (auto& it : processes) {
         if (it.value.name == process_name) {

Userland/pidof.cpp

@@ -12,7 +12,7 @@ static int pid_of(const String& process_name, bool single_shot, bool omit_pid, p
 {
     bool displayed_at_least_one = false;
 
-    HashMap<pid_t, CProcessStatistics> processes = CProcessStatisticsReader().get_map();
+    auto processes = CProcessStatisticsReader().get_all();
 
     for (auto& it : processes) {
         if (it.value.name == process_name) {

Userland/top.cpp

@@ -6,6 +6,7 @@
 #include <AK/QuickSort.h>
 #include <AK/Vector.h>
 #include <LibCore/CFile.h>
+#include <LibCore/CProcessStatisticsReader.h>
 #include <fcntl.h>
 #include <pwd.h>
 #include <stdio.h>
@@ -14,22 +15,15 @@
 
 static HashMap<unsigned, String>* s_usernames;
 
-struct Process {
-    pid_t pid;
-    unsigned nsched;
-    String name;
-    String state;
-    String user;
-    String priority;
-    unsigned virtual_size;
-    unsigned physical_size;
-    unsigned nsched_since_prev;
-    unsigned cpu_percent;
-    unsigned cpu_percent_decimal;
+struct ProcessData {
+    CProcessStatistics stats;
+    unsigned nsched_since_prev { 0 };
+    unsigned cpu_percent { 0 };
+    unsigned cpu_percent_decimal { 0 };
 };
 
 struct Snapshot {
-    HashMap<unsigned, Process> map;
+    HashMap<unsigned, ProcessData> map;
     u32 sum_nsched { 0 };
 };
 
@@ -43,25 +37,16 @@ static Snapshot get_snapshot()
 
     Snapshot snapshot;
 
-    auto file_contents = file.read_all();
-    auto json = JsonValue::from_string({ file_contents.data(), file_contents.size() });
-    json.as_array().for_each([&](auto& value) {
-        const JsonObject& process_object = value.as_object();
-        pid_t pid = process_object.get("pid").to_u32();
-        unsigned nsched = process_object.get("times_scheduled").to_u32();
-        snapshot.sum_nsched += nsched;
-        Process process;
-        process.pid = pid;
-        process.nsched = nsched;
-        unsigned uid = process_object.get("uid").to_u32();
-        process.user = s_usernames->get(uid);
-        process.priority = process_object.get("priority").to_string();
-        process.state = process_object.get("state").to_string();
-        process.name = process_object.get("name").to_string();
-        process.virtual_size = process_object.get("amount_virtual").to_u32();
-        process.physical_size = process_object.get("amount_resident").to_u32();
-        snapshot.map.set(pid, move(process));
-    });
+    auto all_processes = CProcessStatisticsReader::get_all();
+
+    for (auto& it : all_processes) {
+        auto& stats = it.value;
+        snapshot.sum_nsched += stats.nsched;
+        ProcessData process_data;
+        process_data.stats = stats;
+        snapshot.map.set(stats.pid, move(process_data));
+    }
+
     return snapshot;
 }
 
@@ -73,7 +58,7 @@ int main(int, char**)
         s_usernames->set(passwd->pw_uid, passwd->pw_name);
     endpwent();
 
-    Vector<Process*> processes;
+    Vector<ProcessData*> processes;
     auto prev = get_snapshot();
     usleep(10000);
     for (;;) {
@@ -94,11 +79,11 @@ int main(int, char**)
             pid_t pid = it.key;
             if (pid == 0)
                 continue;
-            u32 nsched_now = it.value.nsched;
+            u32 nsched_now = it.value.stats.nsched;
             auto jt = prev.map.find(pid);
             if (jt == prev.map.end())
                 continue;
-            u32 nsched_before = (*jt).value.nsched;
+            u32 nsched_before = (*jt).value.stats.nsched;
             u32 nsched_diff = nsched_now - nsched_before;
             it.value.nsched_since_prev = nsched_diff;
             it.value.cpu_percent = ((nsched_diff * 100) / sum_diff);
@@ -111,16 +96,16 @@ int main(int, char**)
         });
 
         for (auto* process : processes) {
-            printf("%6d  %c    %-8s  %-8s  %6u  %6u  %2u.%1u  %s\n",
-                process->pid,
-                process->priority[0],
-                process->user.characters(),
-                process->state.characters(),
-                process->virtual_size / 1024,
-                process->physical_size / 1024,
+            printf("%6d  %c    %-8s  %-8s  %6zu  %6zu  %2u.%1u  %s\n",
+                process->stats.pid,
+                process->stats.priority[0],
+                process->stats.username.characters(),
+                process->stats.state.characters(),
+                process->stats.virtual_size / 1024,
+                process->stats.physical_size / 1024,
                 process->cpu_percent,
                 process->cpu_percent_decimal,
-                process->name.characters());
+                process->stats.name.characters());
         }
         processes.clear_with_capacity();
         prev = move(current);