Use std::bitset instead of hash_set as there is a fixed set of bits.

2 files changed, 20 insertions, 16 deletions

diff --git a/document/src/vespa/document/select/resultlist.cpp b/document/src/vespa/document/select/resultlist.cpp
index cd633004d26..2058e443c95 100644
--- a/document/src/vespa/document/select/resultlist.cpp
+++ b/document/src/vespa/document/select/resultlist.cpp
@@ -1,7 +1,7 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 
 #include "resultlist.h"
-#include <vespa/vespalib/stllike/hash_set.h>
+#include <bitset>
 #include <ostream>
 
 namespace document::select {
@@ -99,8 +99,7 @@ ResultList::operator&&(const ResultList& other) const
 {
     ResultList results;
 
-    // TODO: optimize
-    vespalib::hash_set<uint32_t> resultForNoVariables;
+    std::bitset<3> resultForNoVariables;
     for (const auto & it : _results) {
         for (const auto & it2 : other._results) {
             fieldvalue::VariableMap vars = it.first;
@@ -108,15 +107,17 @@ ResultList::operator&&(const ResultList& other) const
             if (combineVariables(vars, it2.first)) {
                 const Result & result = *it.second && *it2.second;
                 if (vars.empty()) {
-                    resultForNoVariables.insert(result.toEnum());
+                    resultForNoVariables.set(result.toEnum());
                 } else {
                     results.add(vars, result);
                 }
             }
         }
     }
-    for (uint32_t result : resultForNoVariables) {
-        results.add(fieldvalue::VariableMap(), Result::fromEnum(result));
+    for (uint32_t i(0); i < resultForNoVariables.size(); i++) {
+        if (resultForNoVariables[i]) {
+            results.add(fieldvalue::VariableMap(), Result::fromEnum(i));
+        }
     }
 
     return results;
@@ -127,23 +128,24 @@ ResultList::operator||(const ResultList& other) const
 {
     ResultList results;
 
-    // TODO: optimize
-    vespalib::hash_set<uint32_t> resultForNoVariables;
+    std::bitset<3> resultForNoVariables;
     for (const auto & it : _results) {
         for (const auto & it2 : other._results) {
             fieldvalue::VariableMap vars = it.first;
             if (combineVariables(vars, it2.first)) {
                 const Result & result = *it.second || *it2.second;
                 if (vars.empty()) {
-                    resultForNoVariables.insert(result.toEnum());
+                    resultForNoVariables.set(result.toEnum());
                 } else {
                     results.add(vars, result);
                 }
             }
         }
     }
-    for (uint32_t result : resultForNoVariables) {
-        results.add(fieldvalue::VariableMap(), Result::fromEnum(result));
+    for (uint32_t i(0); i < resultForNoVariables.size(); i++) {
+        if (resultForNoVariables[i]) {
+            results.add(fieldvalue::VariableMap(), Result::fromEnum(i));
+        }
     }
 
     return results;
diff --git a/document/src/vespa/document/select/value.cpp b/document/src/vespa/document/select/value.cpp
index 064598bf2d4..8ada946e702 100644
--- a/document/src/vespa/document/select/value.cpp
+++ b/document/src/vespa/document/select/value.cpp
@@ -3,7 +3,7 @@
 #include "value.h"
 #include "operator.h"
 #include <vespa/document/fieldvalue/fieldvalue.h>
-#include <vespa/vespalib/stllike/hash_set.h>
+#include <bitset>
 #include <ostream>
 
 namespace document::select {
@@ -409,18 +409,20 @@ ArrayValue::doCompare(const Value& value, const Predicate& cmp) const
     } else {
         ResultList results;
 
-        vespalib::hash_set<uint32_t> resultForNoVariables;
+        std::bitset<3> resultForNoVariables;
         // If comparing with other value, must match one.
         for (const auto & item : _values) {
             const Result & result = cmp(*item.second, value).combineResults();
             if (item.first.empty()) {
-                resultForNoVariables.insert(result.toEnum());
+                resultForNoVariables.set(result.toEnum());
             } else {
                 results.add(item.first, result);
             }
         }
-        for (uint32_t result : resultForNoVariables) {
-            results.add(fieldvalue::VariableMap(), Result::fromEnum(result));
+        for (uint32_t i(0); i < resultForNoVariables.size(); i++) {
+            if (resultForNoVariables[i]) {
+                results.add(fieldvalue::VariableMap(), Result::fromEnum(i));
+            }
         }
         return results;
     }