Fix slow processes list update (#130)

* Fix slow processes list update After fix update time 20-60ms fix #129 Co-authored-by: Nathaniel van Diepen <[email protected]>
Eeems-Org · Jan 6, 2021 · 6f3d9a9 · 6f3d9a9
1 parent 59074e4
commit 6f3d9a9
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Showing 3 changed files with 56 additions and 6 deletions.
diff --git a/applications/process-manager/controller.cpp b/applications/process-manager/controller.cpp
@@ -1,5 +1,6 @@
 #include "controller.h"
 #include "taskitem.h"
+
 #include <QIODevice>
 #include <QFile>
 #include <QTextStream>
@@ -8,6 +9,8 @@
 #include <QDir>
 #include <QSet>
 #include <QDebug>
+#include <QMutableListIterator>
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
@@ -30,14 +33,16 @@ void Controller::sortBy(QString key){
 }
 
 QList<QObject*> Controller::getTasks(){
-    tasks.clear();
     QDir directory("/proc");
     if (!directory.exists() || directory.isEmpty()){
+        tasks.clear();
         qCritical() << "Unable to access /proc";
         return tasks;
     }
     directory.setFilter( QDir::Dirs | QDir::NoDot | QDir::NoDotDot);
     auto processes = directory.entryInfoList(QDir::NoFilter, QDir::SortFlag::Name);
+    // Get all pids we care about
+    QList<int> pids;
     for(QFileInfo fi : processes){
         std::string pid = fi.baseName().toStdString();
         if(!is_uint(pid)){
@@ -55,6 +60,22 @@ QList<QObject*> Controller::getTasks(){
         if(content == "0 0 0 0 0 0 0"){
             continue;
         }
+        pids.append(stoi(pid));
+    }
+    // Remove any pids that we've already got cached,
+    // and remove any cached items that no longer exist
+    QMutableListIterator<QObject*> i(tasks);
+    while(i.hasNext()){
+        auto taskItem = reinterpret_cast<TaskItem*>(i.next());
+        const auto pid = taskItem->pid();
+        if(!pids.contains(pid)){
+            i.remove();
+        }else{
+            pids.removeAll(pid);
+        }
+    }
+    // Create TaskItem instances for all new tasks
+    for(auto pid : pids){
         auto taskItem = new TaskItem(pid);
         auto taskPid = taskItem->pid();
         taskItem->setKillable(taskPid != getpid() && taskPid != getppid() && taskPid != protectPid);

diff --git a/applications/process-manager/taskitem.cpp b/applications/process-manager/taskitem.cpp
@@ -25,13 +25,37 @@ string exec(const char* cmd) {
     return result;
 }
 
-TaskItem::TaskItem(const std::string& pid) : QObject(nullptr), _pid(stoi(pid)){
-    std::string path = "/proc/" + to_string(_pid) + "/status";
-    _name = QString::fromStdString(exec(("cat " + path + " | grep Name: | awk '{print$2}'").c_str())).trimmed();
-    _ppid = stoi(exec(("cat " + path + " | grep PPid: | awk '{print$2}'").c_str()));
+TaskItem::TaskItem(int pid) : QObject(nullptr), _pid(pid){
+    QString file_content=readFile(QString::fromStdString("/proc/" + to_string(_pid) + "/status"));
+    _name = parseRegex(file_content,QRegularExpression("^Name:\\t+(\\w+)"));
+    _ppid = parseRegex(file_content,QRegularExpression("^PPid:\\t+(\\d+)",QRegularExpression::MultilineOption)).toInt();
     _killable = _ppid;
 }
 
 bool TaskItem::signal(int signal){
     return kill(_pid, signal);
 }
+
+QString TaskItem::parseRegex(QString &file_content, const QRegularExpression &reg){
+    QRegularExpressionMatchIterator i = reg.globalMatch(file_content);
+    if (!i.isValid()){
+         return "";
+    }
+    QString result="";
+    while (i.hasNext()){
+          QRegularExpressionMatch match = i.next();
+          result=match.captured(1);
+    }
+    return result;
+}
+
+QString TaskItem::readFile(const QString &path){
+    QFile file(path);
+    if(!file.open(QIODevice::ReadOnly)){
+        qDebug()<<"Error reading file: " + path;
+        return "";
+    }
+    auto data = file.readAll();
+    file.close();
+    return data;
+}
diff --git a/applications/process-manager/taskitem.h b/applications/process-manager/taskitem.h
@@ -4,11 +4,14 @@
 #include <QObject>
 #include <QFileInfo>
 #include <string>
+#include <QFile>
+#include <QDebug>
+#include <QRegularExpression>
 
 class TaskItem : public QObject {
     Q_OBJECT
 public:
-    explicit TaskItem(const std::string& pid);
+    explicit TaskItem(int pid);
     Q_PROPERTY(QString name MEMBER _name NOTIFY nameChanged);
     Q_PROPERTY(int pid MEMBER _pid READ pid NOTIFY pidChanged);
     Q_PROPERTY(int ppid MEMBER _ppid NOTIFY ppidChanged);
@@ -33,6 +36,8 @@ class TaskItem : public QObject {
     int _pid;
     int _ppid;
     bool _killable;
+    QString readFile(const QString &path);
+    QString parseRegex(QString &file_content, const QRegularExpression &reg);
 };
 
 #endif // TASKITEM_H