SERVER-9444 Remove context-awareness from Accumulators to prep $group for Sorter

1 files changed, 18 insertions, 14 deletions

diff --git a/src/mongo/db/pipeline/accumulator_min_max.cpp b/src/mongo/db/pipeline/accumulator_min_max.cpp
index c3c5a9790f0..ace2cb34af5 100644
--- a/src/mongo/db/pipeline/accumulator_min_max.cpp
+++ b/src/mongo/db/pipeline/accumulator_min_max.cpp
@@ -21,36 +21,40 @@
 
 namespace mongo {
 
-    void AccumulatorMinMax::processInternal(const Value& input) {
+    void AccumulatorMinMax::processInternal(const Value& input, bool merging) {
         // nullish values should have no impact on result
         if (!input.nullish()) {
             /* compare with the current value; swap if appropriate */
             int cmp = Value::compare(_val, input) * _sense;
-            if (cmp > 0 || _val.missing()) // missing is lower than all other values
+            if (cmp > 0 || _val.missing()) { // missing is lower than all other values
                 _val = input;
+                _memUsageBytes = sizeof(*this) + input.getApproximateSize() - sizeof(Value);
+            }
         }
     }
 
-    Value AccumulatorMinMax::getValue() const {
+    Value AccumulatorMinMax::getValue(bool toBeMerged) const {
         return _val;
     }
 
     AccumulatorMinMax::AccumulatorMinMax(int theSense)
         :_sense(theSense)
-    { verify((_sense == 1) || (_sense == -1)); }
+    {
+        verify((_sense == 1) || (_sense == -1));
+        _memUsageBytes = sizeof(*this);
+    }
+
+    void AccumulatorMinMax::reset() {
+        _val = Value();
+        _memUsageBytes = sizeof(*this);
+    }
 
-    intrusive_ptr<Accumulator> AccumulatorMinMax::createMin(
-        const intrusive_ptr<ExpressionContext> &pCtx) {
-        intrusive_ptr<AccumulatorMinMax> pAccumulator(
-            new AccumulatorMinMax(1));
-        return pAccumulator;
+    intrusive_ptr<Accumulator> AccumulatorMinMax::createMin() {
+        return new AccumulatorMinMax(1);
     }
 
-    intrusive_ptr<Accumulator> AccumulatorMinMax::createMax(
-        const intrusive_ptr<ExpressionContext> &pCtx) {
-        intrusive_ptr<AccumulatorMinMax> pAccumulator(
-            new AccumulatorMinMax(-1));
-        return pAccumulator;
+    intrusive_ptr<Accumulator> AccumulatorMinMax::createMax() {
+        return new AccumulatorMinMax(-1);
     }
 
     const char *AccumulatorMinMax::getOpName() const {