[calc:1.4] Threadsafe and aborting calculations

* libcalculate does not mention any thread safety. lock it.
* Use async calculate(…) function and poll query validity to abort
  unnecessary calculations. This does not only save resources, but is
  also required such that the locks above dont introduce stuttering.

Author: ManuelSchneid3r

calculator_qalculate/CMakeLists.txt

@@ -1,4 +1,4 @@
-project(calculator_qalculate VERSION 1.3)
+project(calculator_qalculate VERSION 1.4)
 albert_plugin(
     NAME Calculator
     DESCRIPTION "Evaluate math expressions using Qalculate"

calculator_qalculate/src/plugin.cpp

@@ -6,6 +6,7 @@
 #include "plugin.h"
 #include "ui_configwidget.h"
 #include <QSettings>
+#include <QThread>
 ALBERT_LOGGING_CATEGORY("qalculate")
 using namespace albert;
 using namespace std;
@@ -18,6 +19,8 @@ const char* CFG_PARSINGMODE = "parsing_mode";
 const uint  DEF_PARSINGMODE = (int)PARSING_MODE_CONVENTIONAL;
 const char* CFG_PRECISION = "precision";
 const uint  DEF_PRECISION = 16;
+const QStringList icon_urls = {"xdg:calc", ":qalculate"};
+std::mutex qalculate_mutex;
 }
 
 Plugin::Plugin()
@@ -65,6 +68,7 @@ QWidget *Plugin::buildConfigWidget()
             static_cast<void(QComboBox::*)(int)>(&QComboBox::currentIndexChanged),
             this, [this](int index){
         settings()->setValue(CFG_ANGLEUNIT, index);
+        std::lock_guard locker(qalculate_mutex);
         eo.parse_options.angle_unit = static_cast<AngleUnit>(index);
     });
 
@@ -74,6 +78,7 @@ QWidget *Plugin::buildConfigWidget()
             static_cast<void(QComboBox::*)(int)>(&QComboBox::currentIndexChanged),
             this, [this](int index){
         settings()->setValue(CFG_PARSINGMODE, index);
+        std::lock_guard locker(qalculate_mutex);
         eo.parse_options.parsing_mode = static_cast<ParsingMode>(index);
     });
 
@@ -83,6 +88,7 @@ QWidget *Plugin::buildConfigWidget()
             static_cast<void(QSpinBox::*)(int)>(&QSpinBox::valueChanged),
             this, [this](int value){
         settings()->setValue(CFG_PRECISION, value);
+        std::lock_guard locker(qalculate_mutex);
         qalc->setPrecision(value);
     });
 
@@ -97,10 +103,24 @@ vector<RankItem> Plugin::handleGlobalQuery(const GlobalQuery *query) const
     if (trimmed.isEmpty())
         return results;
 
+    std::lock_guard locker(qalculate_mutex);
+
     auto expression = qalc->unlocalizeExpression(query->string().toStdString(), eo.parse_options);
-    auto mstruct = qalc->calculate(expression, eo);
+
+    qalc->startControl();
+    MathStructure mstruct;
+    qalc->calculate(&mstruct, expression, 0, eo);
+    for (; qalc->busy(); QThread::msleep(10))
+        if (!query->isValid())
+            qalc->abort();
+    qalc->stopControl();
+
+    if (!query->isValid())
+        return results;
+
     if (qalc->message()){
-        qalc->clearMessages();
+        for (auto msg = qalc->message(); msg; msg = qalc->nextMessage())
+            DEBG << QString::fromUtf8(qalc->message()->c_message());
         return results;
     }
 
@@ -113,7 +133,7 @@ vector<RankItem> Plugin::handleGlobalQuery(const GlobalQuery *query) const
             result,
             QString("%1esult of %2").arg(mstruct.isApproximate()?"Approximate r":"R", trimmed),
             result,   // TODO if handler finally knows its trigger change this to fire a triggered query
-            {"xdg:calc", ":qalculate"},
+            icon_urls,
             {
                 {
                     "cpr", "Copy result to clipboard",
@@ -129,35 +149,46 @@ vector<RankItem> Plugin::handleGlobalQuery(const GlobalQuery *query) const
     return results;
 }
 
-
-
 void Plugin::handleTriggerQuery(TriggerQuery *query) const
 {
     auto trimmed = query->string().trimmed();
     if (trimmed.isEmpty())
         return;
 
+    std::lock_guard locker(qalculate_mutex);
+
     auto eo_ = eo;
     eo_.parse_options.functions_enabled = true;
     eo_.parse_options.units_enabled = true;
     eo_.parse_options.unknowns_enabled = true;
 
     auto expression = qalc->unlocalizeExpression(query->string().toStdString(), eo_.parse_options);
-    auto mstruct = qalc->calculate(expression, eo_);
+
+    qalc->startControl();
+    MathStructure mstruct;
+    qalc->calculate(&mstruct, expression, 0, eo_);
+    for (; qalc->busy(); QThread::msleep(10))
+        if (!query->isValid())
+            qalc->abort();
+    qalc->stopControl();
+
+    if (!query->isValid())
+        return;
+
     QStringList errors;
     for (auto msg = qalc->message(); msg; msg = qalc->nextMessage())
         errors << QString::fromUtf8(qalc->message()->c_message());
-    mstruct.format(po);
 
     if (errors.empty()){
+        mstruct.format(po);
         auto result = QString::fromStdString(mstruct.print(po));
         query->add(
             StandardItem::make(
                 "qalc-res",
                 result,
                 QString("%1esult of %2").arg(mstruct.isApproximate()?"Approximate r":"R", trimmed),
                 QString("%1%2").arg(query->trigger(), result),
-                {"xdg:calc", ":qalculate"},
+                icon_urls,
                 {
                     {
                         "cpr", "Copy result to clipboard",
@@ -176,7 +207,7 @@ void Plugin::handleTriggerQuery(TriggerQuery *query) const
                 "qalc-err",
                 "Evaluation error.",
                 errors.join(" "),
-                {"xdg:calc", ":qalculate"},
+                icon_urls,
                 {{"manual", "Visit documentation", [=](){ openUrl(URL_MANUAL); }}}
             )
         );

calculator_qalculate/src/plugin.h

@@ -1,8 +1,8 @@
 // Copyright (C) 2023 Manuel Schneider
 
 #pragma once
-#include "albert/plugin.h"
 #include "albert/extension/queryhandler/globalqueryhandler.h"
+#include "albert/plugin.h"
 #include <QObject>
 #include <libqalculate/Calculator.h>
 #include <memory>
@@ -25,8 +25,3 @@ class Plugin : public albert::plugin::ExtensionPlugin<albert::GlobalQueryHandler
     EvaluationOptions eo;
     PrintOptions po;
 };
-
-
-
-//    void setGroupSeparatorEnabled(bool enabled);
-//    void setIParserEnabled(bool enabled);