From 710e631137a08948fc9458f663119c5e10b90a4c 2017-09-05 16:19:19
From: Alexandre Leroux <aleroux@itlink.fr>
Date: 2017-09-05 16:19:19
Subject: [PATCH] Improves random access iterator performance

---

diff --git a/core/include/Data/ArrayData.h b/core/include/Data/ArrayData.h
index a07dc93..a1aad29 100644
--- a/core/include/Data/ArrayData.h
+++ b/core/include/Data/ArrayData.h
@@ -121,13 +121,11 @@ public:
     std::unique_ptr<ArrayDataIteratorValue::Impl> advance(int offset) const override
     {
         auto result = clone();
-        while (offset--) {
-            result->next();
-        }
+        result->next(offset);
         return result;
     }
 
-    void next() override { std::advance(m_It, m_NbComponents); }
+    void next(int offset) override { std::advance(m_It, offset * m_NbComponents); }
     void prev() override { std::advance(m_It, -m_NbComponents); }
 
     double at(int componentIndex) const override { return *(m_It + componentIndex); }
diff --git a/core/include/Data/ArrayDataIterator.h b/core/include/Data/ArrayDataIterator.h
index 040f5f1..0bca05d 100644
--- a/core/include/Data/ArrayDataIterator.h
+++ b/core/include/Data/ArrayDataIterator.h
@@ -23,7 +23,7 @@ public:
         virtual bool equals(const Impl &other) const = 0;
         virtual bool lowerThan(const Impl &other) const = 0;
         virtual std::unique_ptr<Impl> advance(int offset) const = 0;
-        virtual void next() = 0;
+        virtual void next(int offset) = 0;
         virtual void prev() = 0;
         virtual double at(int componentIndex) const = 0;
         virtual double first() const = 0;
@@ -44,7 +44,7 @@ public:
 
     ArrayDataIteratorValue advance(int offset) const;
     /// Advances to the next value
-    void next();
+    void next(int offset = 1);
     /// Moves back to the previous value
     void prev();
     /// Gets value of a specified component
diff --git a/core/include/Data/DataSeries.h b/core/include/Data/DataSeries.h
index 7e4f998..63684ea 100644
--- a/core/include/Data/DataSeries.h
+++ b/core/include/Data/DataSeries.h
@@ -81,16 +81,14 @@ public:
     std::unique_ptr<DataSeriesIteratorValue::Impl> advance(int offset) const override
     {
         auto result = clone();
-        while (offset--) {
-            result->next();
-        }
+        result->next(offset);
         return result;
     }
 
-    void next() override
+    void next(int offset) override
     {
-        ++m_XIt;
-        ++m_ValuesIt;
+        m_XIt->next(offset);
+        m_ValuesIt->next(offset);
     }
 
     void prev() override
diff --git a/core/include/Data/DataSeriesIterator.h b/core/include/Data/DataSeriesIterator.h
index ae0f7fa..a6b1f05 100644
--- a/core/include/Data/DataSeriesIterator.h
+++ b/core/include/Data/DataSeriesIterator.h
@@ -24,7 +24,7 @@ public:
         virtual bool equals(const Impl &other) const = 0;
         virtual bool lowerThan(const Impl &other) const = 0;
         virtual std::unique_ptr<Impl> advance(int offset) const = 0;
-        virtual void next() = 0;
+        virtual void next(int offset) = 0;
         virtual void prev() = 0;
         virtual double x() const = 0;
         virtual double value() const = 0;
@@ -46,7 +46,7 @@ public:
 
     DataSeriesIteratorValue advance(int offset) const;
     /// Advances to the next value
-    void next();
+    void next(int offset = 1);
     /// Moves back to the previous value
     void prev();
     /// Gets x-axis data
diff --git a/core/include/Data/SqpIterator.h b/core/include/Data/SqpIterator.h
index dcb0203..aae9315 100644
--- a/core/include/Data/SqpIterator.h
+++ b/core/include/Data/SqpIterator.h
@@ -52,9 +52,7 @@ public:
     SqpIterator &operator+=(int offset)
     {
         if (offset >= 0) {
-            while (offset--) {
-                m_CurrentValue.next();
-            }
+            m_CurrentValue.next(offset);
         }
         else {
             while (offset++) {
diff --git a/core/src/Data/ArrayDataIterator.cpp b/core/src/Data/ArrayDataIterator.cpp
index 77734f2..70b47c2 100644
--- a/core/src/Data/ArrayDataIterator.cpp
+++ b/core/src/Data/ArrayDataIterator.cpp
@@ -36,9 +36,9 @@ ArrayDataIteratorValue ArrayDataIteratorValue::advance(int offset) const
     return ArrayDataIteratorValue{m_Impl->advance(offset)};
 }
 
-void ArrayDataIteratorValue::next()
+void ArrayDataIteratorValue::next(int offset)
 {
-    m_Impl->next();
+    m_Impl->next(offset);
 }
 
 void ArrayDataIteratorValue::prev()
diff --git a/core/src/Data/DataSeriesIterator.cpp b/core/src/Data/DataSeriesIterator.cpp
index 06a300b..a02ca2d 100644
--- a/core/src/Data/DataSeriesIterator.cpp
+++ b/core/src/Data/DataSeriesIterator.cpp
@@ -38,9 +38,9 @@ DataSeriesIteratorValue DataSeriesIteratorValue::advance(int offset) const
     return DataSeriesIteratorValue{m_Impl->advance(offset)};
 }
 
-void DataSeriesIteratorValue::next()
+void DataSeriesIteratorValue::next(int offset)
 {
-    m_Impl->next();
+    m_Impl->next(offset);
 }
 
 void DataSeriesIteratorValue::prev()