Support GetFilters() in core::Filter (#10401)

Author: cherylEnkidu

Firestore/core/src/core/composite_filter.h

@@ -138,6 +138,10 @@ class CompositeFilter : public Filter {
 
     const model::FieldPath* GetFirstInequalityField() const override;
 
+    std::vector<Filter> GetFilters() const override {
+      return filters();
+    }
+
     /**
      * Performs a depth-first search to find and return the first FieldFilter in
      * the composite filter that satisfies the condition. Returns nullptr if

Firestore/core/src/core/field_filter.cc

@@ -131,6 +131,12 @@ const std::vector<FieldFilter>& FieldFilter::Rep::GetFlattenedFilters() const {
   return Filter::Rep::memoized_flattened_filters_;
 }
 
+std::vector<Filter> FieldFilter::Rep::GetFilters() const {
+  // This is the only filter within this object, so we return a list of size
+  // one.
+  return std::vector<Filter>{FieldFilter(std::make_shared<const Rep>(*this))};
+}
+
 FieldFilter::Rep::Rep(FieldPath field,
                       Operator op,
                       SharedMessage<google_firestore_v1_Value> value_rhs)

Firestore/core/src/core/field_filter.h

@@ -121,6 +121,8 @@ class FieldFilter : public Filter {
 
     const std::vector<FieldFilter>& GetFlattenedFilters() const override;
 
+    std::vector<Filter> GetFilters() const override;
+
    protected:
     /**
      * Creates a new filter that compares fields and values. Only intended to be

Firestore/core/src/core/filter.h

@@ -110,6 +110,13 @@ class Filter {
     return rep_->GetFlattenedFilters();
   }
 
+  /**
+   * Returns a list of all filters that are contained within this filter
+   */
+  std::vector<Filter> GetFilters() const {
+    return rep_->GetFilters();
+  }
+
   friend bool operator==(const Filter& lhs, const Filter& rhs);
 
  protected:
@@ -150,6 +157,8 @@ class Filter {
 
     virtual const std::vector<FieldFilter>& GetFlattenedFilters() const = 0;
 
+    virtual std::vector<Filter> GetFilters() const = 0;
+
     /**
      * Memoized list of all field filters that can be found by
      * traversing the tree of filters contained in this composite filter.

Firestore/core/src/local/leveldb_index_manager.cc

@@ -957,18 +957,9 @@ std::vector<Target> LevelDbIndexManager::GetSubTargets(const Target& target) {
     std::vector<Filter> dnf = LogicUtils::GetDnfTerms(CompositeFilter::Create(
         std::move(filters), CompositeFilter::Operator::And));
 
-    // TODO(orquery): Add getFilters() in Filter class.
     for (const Filter& term : dnf) {
-      std::vector<Filter> subfilters;
-      if (term.IsAFieldFilter()) {
-        subfilters.push_back(term);
-      } else if (term.IsACompositeFilter()) {
-        for (const auto& filter : (CompositeFilter(term)).filters()) {
-          subfilters.push_back(filter);
-        }
-      }
       subtargets.push_back({target.path(), target.collection_group(),
-                            std::move(subfilters), target.order_bys(),
+                            term.GetFilters(), target.order_bys(),
                             target.limit(), target.start_at(),
                             target.end_at()});
     }

Firestore/core/src/remote/serializer.cc

@@ -908,7 +908,7 @@ google_firestore_v1_StructuredQuery_Filter Serializer::EncodeUnaryOrFieldFilter(
 google_firestore_v1_StructuredQuery_Filter Serializer::EncodeCompositeFilter(
     const core::CompositeFilter& filter) const {
   // If there's only one filter in the composite filter, use it directly.
-  if (filter.filters().size() == 1u) {
+  if (filter.filters().size() == 1U) {
     return EncodeFilter(filter.filters()[0]);
   }
 

Firestore/core/src/util/logic_utils.cc

@@ -270,8 +270,7 @@ std::vector<core::Filter> LogicUtils::GetDnfTerms(
     return {std::move(result)};
   }
 
-  const CompositeFilter composite_filter(result);
-  return composite_filter.filters();
+  return result.GetFilters();
 }
 
 }  // namespace util