From 26e030a6bc56ccdb7e5a539017022738fe2cb85f Mon Sep 17 00:00:00 2001
From: Adam Schroder <adamschroder@gmail.com>
Date: Wed, 23 Nov 2016 17:23:13 +1100
Subject: [PATCH] Use GetValues once per row rather than GetValue each per
 field.

---
 src/NPoco/RowMappers/PropertyMapper.cs   | 24 +++++++++++++-----------
 test/NPoco.Tests/NewMapper/FakeReader.cs | 10 ++++++++--
 2 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/src/NPoco/RowMappers/PropertyMapper.cs b/src/NPoco/RowMappers/PropertyMapper.cs
index 139feb98..39b50176 100644
--- a/src/NPoco/RowMappers/PropertyMapper.cs
+++ b/src/NPoco/RowMappers/PropertyMapper.cs
@@ -42,7 +42,9 @@ public override object Map(DbDataReader dataReader, RowMapperContext context)
                 _mappingOntoExistingInstance = true;
             }
 
-            _mapPlan(dataReader, context.Instance);
+            object[] values = new object[dataReader.FieldCount];
+            dataReader.GetValues(values);
+            _mapPlan(dataReader, values, context.Instance);
 
             var result = context.Instance as IOnLoaded;
             if (result != null)
@@ -53,16 +55,16 @@ public override object Map(DbDataReader dataReader, RowMapperContext context)
             return context.Instance;
         }
 
-        public delegate bool MapPlan(DbDataReader reader, object instance);
+        public delegate bool MapPlan(DbDataReader dataReader, object[] reader, object instance);
 
         private MapPlan BuildMapPlan(DbDataReader dataReader, PocoData pocoData)
         {
             var plans = _groupedNames.SelectMany(x => BuildMapPlans(x, dataReader, pocoData, pocoData.Members)).ToArray();
-            return (reader, instance) =>
+            return (reader, values, instance) =>
             {
                 foreach (MapPlan plan in plans)
                 {
-                    plan(reader, instance);
+                    plan(reader, values, instance);
                 }
                 return true;
             };
@@ -89,14 +91,14 @@ private IEnumerable<MapPlan> BuildMapPlans(GroupResult<PosName> groupedName, DbD
 
                     var subPlans = groupedName.SubItems.SelectMany(x => BuildMapPlans(x, dataReader, pocoData, children)).ToArray();
 
-                    yield return (reader, instance) =>
+                    yield return (reader, values, instance) =>
                     {
                         var newObject = pocoMember.IsList ? pocoMember.Create(dataReader) : (pocoMember.GetValue(instance) ?? pocoMember.Create(dataReader));
 
                         var shouldSetNestedObject = false;
                         foreach (var subPlan in subPlans)
                         {
-                            shouldSetNestedObject |= subPlan(reader, newObject);
+                            shouldSetNestedObject |= subPlan(reader, values, newObject);
                         }
 
                         if (shouldSetNestedObject)
@@ -120,7 +122,7 @@ private IEnumerable<MapPlan> BuildMapPlans(GroupResult<PosName> groupedName, DbD
                 var destType = pocoMember.MemberInfoData.MemberType;
                 var defaultValue = MappingHelper.GetDefault(destType);
                 var converter = GetConverter(pocoData, pocoMember.PocoColumn, dataReader.GetFieldType(groupedName.Key.Pos), destType);
-                yield return (reader, instance) => MapValue(groupedName, reader, converter, instance, pocoMember.PocoColumn, defaultValue);
+                yield return (reader, values, instance) => MapValue(groupedName, values, converter, instance, pocoMember.PocoColumn, defaultValue);
             }
         }
 
@@ -130,12 +132,12 @@ public static bool IsEqual(string name, string value)
                 || string.Equals(value, name.Replace("_", ""), StringComparison.OrdinalIgnoreCase);
         }
 
-        private bool MapValue(GroupResult<PosName> posName, DbDataReader reader, Func<object, object> converter, object instance, PocoColumn pocoColumn, object defaultValue)
+        private bool MapValue(GroupResult<PosName> posName, object[] values, Func<object, object> converter, object instance, PocoColumn pocoColumn, object defaultValue)
         {
-            if (!reader.IsDBNull(posName.Key.Pos))
+            var value = values[posName.Key.Pos];
+            if (!Equals(value, DBNull.Value))
             {
-                var value = converter != null ? converter(reader.GetValue(posName.Key.Pos)) : reader.GetValue(posName.Key.Pos);
-                pocoColumn.SetValue(instance, value);
+                pocoColumn.SetValue(instance, converter != null ? converter(value) : value);
                 return true;
             }
 
diff --git a/test/NPoco.Tests/NewMapper/FakeReader.cs b/test/NPoco.Tests/NewMapper/FakeReader.cs
index d3507f5b..621518c6 100644
--- a/test/NPoco.Tests/NewMapper/FakeReader.cs
+++ b/test/NPoco.Tests/NewMapper/FakeReader.cs
@@ -94,7 +94,13 @@ public override string GetName(int i)
 
         public override int GetValues(object[] values)
         {
-            throw new NotImplementedException();
+            values[0] = "Name";
+            values[1] = 5;
+            values[2] = 23m;
+            values[3] = "AUD";
+            values[4] = 24m;
+            values[5] = "USD";
+            return 1;
         }
 
         public override int GetOrdinal(string name)
@@ -170,7 +176,7 @@ public override bool IsDBNull(int i)
             return false;
         }
 
-        public override int FieldCount { get { return 4; } }
+        public override int FieldCount { get { return 6; } }
 
         public override object this[int ordinal]
         {