[7.x][ML] Always use Boost unordered maps/sets (elastic#1652)

The memory instrumentation in core::CMemory exists for
boost::unordered_set and boost::unordered_map, but not
the std equivalents.  It is better that we switch all
uses in the codebase at the same time (or even switch
to completely different hash container implementations).

This change switches the few cases of std::unordered_map
and std::unordered_set to the boost versions.  This may
cause some increases in reported memory usage, where these
containers are in memory instrumented classes.  It won't
increase actual memory usage (at least not significantly),
just make the reporting more accurate.

Backport of elastic#1647

include/api/CBoostedTreeInferenceModelBuilder.h

@@ -14,6 +14,8 @@
 
 #include <rapidjson/document.h>
 
+#include <boost/unordered_map.hpp>
+
 #include <string>
 
 namespace ml {
@@ -25,7 +27,7 @@ class API_EXPORT CBoostedTreeInferenceModelBuilder : public maths::CBoostedTree:
     using TDoubleVec = std::vector<double>;
     using TStrVec = std::vector<std::string>;
     using TStrVecVec = std::vector<TStrVec>;
-    using TSizeStringUMap = std::unordered_map<std::size_t, std::string>;
+    using TSizeStringUMap = boost::unordered_map<std::size_t, std::string>;
     using TSizeStringUMapVec = std::vector<TSizeStringUMap>;
     using TVector = maths::CBoostedTreeNode::TVector;
     using TApiCustomEncodingUPtr = std::unique_ptr<api::CCustomEncoding>;
@@ -59,8 +61,8 @@ class API_EXPORT CBoostedTreeInferenceModelBuilder : public maths::CBoostedTree:
 
 private:
     using TOneHotEncodingUPtr = std::unique_ptr<COneHotEncoding>;
-    using TOneHotEncodingUMap = std::unordered_map<std::string, TOneHotEncodingUPtr>;
-    using TStringDoubleUMap = std::unordered_map<std::string, double>;
+    using TOneHotEncodingUMap = boost::unordered_map<std::string, TOneHotEncodingUPtr>;
+    using TStringDoubleUMap = boost::unordered_map<std::string, double>;
 
 private:
     virtual void setTargetType() = 0;

include/api/CDataFrameAnalysisInstrumentation.h

@@ -21,7 +21,6 @@
 #include <cstdint>
 #include <memory>
 #include <mutex>
-#include <unordered_map>
 
 namespace ml {
 namespace api {

include/api/CInferenceModelDefinition.h

@@ -16,10 +16,10 @@
 #include <rapidjson/ostreamwrapper.h>
 
 #include <boost/optional.hpp>
+#include <boost/unordered_map.hpp>
 
 #include <sstream>
 #include <string>
-#include <unordered_map>
 #include <vector>
 
 namespace ml {
@@ -354,7 +354,7 @@ class API_EXPORT CFrequencyEncoding final : public CEncoding {
     private:
         const CFrequencyEncoding& m_Encoding;
     };
-    using TStringDoubleUMap = const std::unordered_map<std::string, double>;
+    using TStringDoubleUMap = const boost::unordered_map<std::string, double>;
 
 public:
     ~CFrequencyEncoding() override = default;
@@ -417,7 +417,7 @@ class API_EXPORT CTargetMeanEncoding final : public CEncoding {
     private:
         const CTargetMeanEncoding& m_Encoding;
     };
-    using TStringDoubleUMap = std::unordered_map<std::string, double>;
+    using TStringDoubleUMap = boost::unordered_map<std::string, double>;
 
 public:
     ~CTargetMeanEncoding() override = default;
@@ -462,9 +462,9 @@ class API_EXPORT CInferenceModelDefinition : public CSerializableToJsonStream {
     using TApiCustomEncodingUPtr = std::unique_ptr<api::CCustomEncoding>;
     using TApiCustomEncodingUPtrVec = std::vector<TApiCustomEncodingUPtr>;
     using TRapidJsonWriter = core::CRapidJsonConcurrentLineWriter;
-    using TSizeStringUMap = std::unordered_map<std::size_t, std::string>;
+    using TSizeStringUMap = boost::unordered_map<std::size_t, std::string>;
     using TSizeStringUMapVec = std::vector<TSizeStringUMap>;
-    using TStringSizeUMap = std::unordered_map<std::string, std::size_t>;
+    using TStringSizeUMap = boost::unordered_map<std::string, std::size_t>;
     using TStringSizeUMapVec = std::vector<TStringSizeUMap>;
     using TStringVec = std::vector<std::string>;
     using TTrainedModelUPtr = CEnsemble::TTrainedModelUPtr;

include/api/CInferenceModelMetadata.h

@@ -13,6 +13,8 @@
 #include <api/CInferenceModelDefinition.h>
 #include <api/ImportExport.h>
 
+#include <boost/unordered_map.hpp>
+
 #include <string>
 #include <tuple>
 
@@ -83,8 +85,8 @@ class API_EXPORT CInferenceModelMetadata {
     using TMeanAccumulator =
         std::vector<maths::CBasicStatistics::SSampleMean<double>::TAccumulator>;
     using TMinMaxAccumulator = std::vector<maths::CBasicStatistics::CMinMax<double>>;
-    using TSizeMeanAccumulatorUMap = std::unordered_map<std::size_t, TMeanAccumulator>;
-    using TSizeMinMaxAccumulatorUMap = std::unordered_map<std::size_t, TMinMaxAccumulator>;
+    using TSizeMeanAccumulatorUMap = boost::unordered_map<std::size_t, TMeanAccumulator>;
+    using TSizeMinMaxAccumulatorUMap = boost::unordered_map<std::size_t, TMinMaxAccumulator>;
     using TOptionalVector = boost::optional<TVector>;
     using THyperparametersVec = std::vector<SHyperparameterImportance>;
 

lib/api/CInferenceModelDefinition.cc

@@ -12,13 +12,13 @@
 
 #include <boost/iostreams/filter/gzip.hpp>
 #include <boost/iostreams/filtering_stream.hpp>
+#include <boost/unordered_map.hpp>
+#include <boost/unordered_set.hpp>
 
 #include <cmath>
 #include <iterator>
 #include <memory>
 #include <ostream>
-#include <unordered_map>
-#include <unordered_set>
 
 namespace ml {
 namespace api {
@@ -280,7 +280,7 @@ void CEnsemble::targetType(ETargetType targetType) {
 }
 
 CTrainedModel::TStringVec CEnsemble::removeUnusedFeatures() {
-    std::unordered_set<std::string> set;
+    boost::unordered_set<std::string> set;
     for (auto& trainedModel : this->trainedModels()) {
         TStringVec vec(trainedModel->removeUnusedFeatures());
         set.insert(vec.begin(), vec.end());
@@ -380,7 +380,7 @@ CTree::TTreeNodeVec& CTree::treeStructure() {
 }
 
 CTrainedModel::TStringVec CTree::removeUnusedFeatures() {
-    std::unordered_map<std::size_t, std::size_t> selectedFeatureIndices;
+    boost::unordered_map<std::size_t, std::size_t> selectedFeatureIndices;
     for (auto& treeNode : m_TreeStructure) {
         if (treeNode.leaf() == false) {
             std::size_t adjustedIndex{selectedFeatureIndices

lib/model/unittest/CEventRatePopulationModelTest.cc

@@ -39,13 +39,13 @@
 #include <boost/test/unit_test.hpp>
 #include <boost/tuple/tuple.hpp>
 #include <boost/tuple/tuple_comparison.hpp>
+#include <boost/unordered_map.hpp>
 
 #include <algorithm>
 #include <cstddef>
 #include <map>
 #include <set>
 #include <string>
-#include <unordered_map>
 #include <utility>
 #include <vector>
 
@@ -279,15 +279,15 @@ BOOST_FIXTURE_TEST_CASE(testFeatures, CTestFixture) {
         }
 
     private:
-        using TDoubleSizeUMap = std::unordered_map<double, std::size_t>;
+        using TDoubleSizeUMap = boost::unordered_map<double, std::size_t>;
 
     private:
         TDoubleSizeUMap m_Uniques;
         TDouble2VecVec m_Values;
         TDouble2VecWeightsAryVec m_TrendWeights;
         TDouble2VecWeightsAryVec m_ResidualWeights;
     };
-    using TSizeUniqueValuesUMap = std::unordered_map<std::size_t, CUniqueValues>;
+    using TSizeUniqueValuesUMap = boost::unordered_map<std::size_t, CUniqueValues>;
 
     core_t::TTime startTime = 1367280000;
     const core_t::TTime bucketLength = 3600;