Optimize LinkedList getAt(), don't use it if possible

source/backend/engine/CarlaEngineClient.cpp

@@ -144,7 +144,7 @@ const char* CarlaEngineClient::getAudioPortName(const bool isInput, const uint i
     CarlaStringList& portList(isInput ? pData->audioInList : pData->audioOutList);
     CARLA_SAFE_ASSERT_RETURN(index < portList.count(), nullptr);
 
-    return portList.getAt(index, nullptr);
+    return portList.getAt(index);
 }
 
 const char* CarlaEngineClient::getCVPortName(const bool isInput, const uint index) const noexcept
@@ -152,7 +152,7 @@ const char* CarlaEngineClient::getCVPortName(const bool isInput, const uint inde
     CarlaStringList& portList(isInput ? pData->cvInList : pData->cvOutList);
     CARLA_SAFE_ASSERT_RETURN(index < portList.count(), nullptr);
 
-    return portList.getAt(index, nullptr);
+    return portList.getAt(index);
 }
 
 const char* CarlaEngineClient::getEventPortName(const bool isInput, const uint index) const noexcept
@@ -160,7 +160,7 @@ const char* CarlaEngineClient::getEventPortName(const bool isInput, const uint i
     CarlaStringList& portList(isInput ? pData->eventInList : pData->eventOutList);
     CARLA_SAFE_ASSERT_RETURN(index < portList.count(), nullptr);
 
-    return portList.getAt(index, nullptr);
+    return portList.getAt(index);
 }
 
 void CarlaEngineClient::_addAudioPortName(const bool isInput, const char* const name)

source/backend/plugin/CarlaPlugin.cpp

@@ -263,7 +263,6 @@ const MidiProgramData& CarlaPlugin::getMidiProgramData(const uint32_t index) con
 
 const CustomData& CarlaPlugin::getCustomData(const uint32_t index) const noexcept
 {
-    CARLA_SAFE_ASSERT_RETURN(index < pData->custom.count(), kCustomDataNull);
     return pData->custom.getAt(index, kCustomDataFallback);
 }
 

source/native-plugins/zynaddsubfx-synth.cpp

@@ -49,20 +49,18 @@ public:
 #ifdef CARLA_PROPER_CPP11_SUPPORT
           fRetProgram({0, 0, nullptr}),
 #endif
-          fPrograms() {}
+          fProgramCount(0),
+          fPrograms(nullptr) {}
 
     ~ZynAddSubFxPrograms() noexcept
     {
         if (! fInitiated)
             return;
 
-        for (LinkedList<const ProgramInfo*>::Itenerator it = fPrograms.begin2(); it.valid(); it.next())
-        {
-            const ProgramInfo* const& pInfo(it.getValue(nullptr));
-            delete pInfo;
-        }
+        for (uint32_t i=0; i<fProgramCount; ++i)
+            delete fPrograms[i];
 
-        fPrograms.clear();
+        delete[] fPrograms;
     }
 
     void initIfNeeded()
@@ -71,7 +69,8 @@ public:
             return;
         fInitiated = true;
 
-        fPrograms.append(new ProgramInfo(0, 0, "default", ""));
+        std::vector<const ProgramInfo*> programs;
+        programs.push_back(new ProgramInfo(0, 0, "default", ""));
 
         Config config;
         config.init();
@@ -98,22 +97,27 @@ public:
                 if (instrument.name.empty() || instrument.name[0] == ' ')
                     continue;
 
-                fPrograms.append(new ProgramInfo(i+1, ninstrument, instrument.name.c_str(), instrument.filename.c_str()));
+                programs.push_back(new ProgramInfo(i+1, ninstrument, instrument.name.c_str(), instrument.filename.c_str()));
             }
         }
+
+        fPrograms = new const ProgramInfo*[programs.size()];
+
+        for (const ProgramInfo* p : programs)
+            fPrograms[fProgramCount++] = p;
     }
 
     uint32_t getNativeMidiProgramCount() const noexcept
     {
-        return static_cast<uint32_t>(fPrograms.count());
+        return fProgramCount;
     }
 
     const NativeMidiProgram* getNativeMidiProgramInfo(const uint32_t index) const noexcept
     {
-        if (index >= fPrograms.count())
+        if (index >= fProgramCount)
             return nullptr;
 
-        const ProgramInfo* const pInfo(fPrograms.getAt(index, nullptr));
+        const ProgramInfo* const pInfo(fPrograms[index]);
         CARLA_SAFE_ASSERT_RETURN(pInfo != nullptr, nullptr);
 
         fRetProgram.bank    = pInfo->bank;
@@ -125,9 +129,9 @@ public:
 
     const char* getZynProgramFilename(const uint32_t bank, const uint32_t program) const noexcept
     {
-        for (LinkedList<const ProgramInfo*>::Itenerator it = fPrograms.begin2(); it.valid(); it.next())
+        for (uint32_t i=0; i<fProgramCount; ++i)
         {
-            const ProgramInfo* const& pInfo(it.getValue(nullptr));
+            const ProgramInfo* const pInfo(fPrograms[i]);
 
             if (pInfo->bank != bank)
                 continue;
@@ -179,7 +183,8 @@ private:
 
     bool fInitiated;
     mutable NativeMidiProgram fRetProgram;
-    LinkedList<const ProgramInfo*> fPrograms;
+    uint32_t fProgramCount;
+    const ProgramInfo** fPrograms;
 
     CARLA_PREVENT_HEAP_ALLOCATION
     CARLA_DECLARE_NON_COPY_CLASS(ZynAddSubFxPrograms)

source/plugin/carla-lv2.cpp

@@ -1753,11 +1753,15 @@ const LV2_Descriptor* lv2_descriptor(uint32_t index)
     /* extension_data */ lv2_extension_data
     };
 
-    LV2_Descriptor* const lv2Desc(new LV2_Descriptor);
+    LV2_Descriptor* lv2Desc;
+
+    try {
+        lv2Desc = new LV2_Descriptor;
+    } CARLA_SAFE_EXCEPTION_RETURN("new LV2_Descriptor", nullptr);
+
     std::memcpy(lv2Desc, &lv2DescTmp, sizeof(LV2_Descriptor));
 
     plm.lv2Descs.append(lv2Desc);
-
     return lv2Desc;
 }
 

source/utils/CarlaStringList.hpp

@@ -244,6 +244,23 @@ public:
 
     // -------------------------------------------------------------------
 
+    const char* getAt(const std::size_t index) const noexcept
+    {
+        CARLA_SAFE_ASSERT_RETURN(fCount > 0 && index < fCount, nullptr);
+
+        std::size_t i = 0;
+        ListHead* entry = fQueue.next;
+
+        for (; i++ != index; entry = entry->next) {}
+
+        const Data* const data(list_entry_const(entry, Data, siblings));
+        CARLA_SAFE_ASSERT_RETURN(data != nullptr, nullptr);
+
+        return data->value;
+    }
+
+    // -------------------------------------------------------------------
+
     void remove(Itenerator& it) noexcept
     {
         if (const char* const string = it.getValue(nullptr))

source/utils/LinkedList.hpp

@@ -252,55 +252,17 @@ public:
         return _add(value, false, it.fEntry->prev);
     }
 
-    T getAt(const std::size_t index, T& fallback, const bool removeObj) noexcept
-    {
-        CARLA_SAFE_ASSERT_RETURN(fCount > 0 && index < fCount, fallback);
-
-        std::size_t i = 0;
-
-        for (ListHead *entry = fQueue.next, *entry2 = entry->next; entry != &fQueue; entry = entry2, entry2 = entry->next)
-        {
-            if (index != i++)
-                continue;
-
-            return _get(entry, fallback, removeObj);
-        }
-
-        return fallback;
-    }
-
-    T& getAt(const std::size_t index, T& fallback) const noexcept
-    {
-        CARLA_SAFE_ASSERT_RETURN(fCount > 0 && index < fCount, fallback);
-
-        std::size_t i = 0;
-
-        for (ListHead *entry = fQueue.next, *entry2 = entry->next; entry != &fQueue; entry = entry2, entry2 = entry->next)
-        {
-            if (index != i++)
-                continue;
-
-            return _get(entry, fallback);
-        }
-
-        return fallback;
-    }
-
+    // NOTE: do not use this function unless strictly needed. it can be very expensive if the list is big
     const T& getAt(const std::size_t index, const T& fallback) const noexcept
     {
         CARLA_SAFE_ASSERT_RETURN(fCount > 0 && index < fCount, fallback);
 
         std::size_t i = 0;
+        ListHead* entry = fQueue.next;
 
-        for (ListHead *entry = fQueue.next, *entry2 = entry->next; entry != &fQueue; entry = entry2, entry2 = entry->next)
-        {
-            if (index != i++)
-                continue;
-
-            return _get(entry, fallback);
-        }
+        for (; i++ != index; entry = entry->next) {}
 
-        return fallback;
+        return _get(entry, fallback);
     }
 
     T getFirst(T& fallback, const bool removeObj) noexcept
@@ -502,7 +464,7 @@ private:
         return data->value;
     }
 
-    const T& _get(ListHead* const entry, const T& fallback) const noexcept
+    const T& _get(const ListHead* const entry, const T& fallback) const noexcept
     {
         const Data* const data(list_entry_const(entry, Data, siblings));
         CARLA_SAFE_ASSERT_RETURN(data != nullptr, fallback);