Implement Overlap queries

Summary:
Notes:

- Introduces the concept of queries on multiple properties (which meant changing query's internals a bit)
- Dates are stored as well as the "reference" in the index to allow quick filtering without fetching the whole entity
- Buckets are weeks starting on Monday (guaranteed by the use of the Julian calendar)
- Some size improvements are definitely possible (dates are padded numbers again, not using integer databases, Julian calendar starts at a very old date, etc.)

Test Plan: Tested in querytest

Reviewers: cmollekopf

Reviewed By: cmollekopf

Tags: #sink

Differential Revision: https://phabricator.kde.org/D13477

2 files changed, 22 insertions, 1 deletions

diff --git a/common/domain/typeimplementations.cpp b/common/domain/typeimplementations.cpp
index a8f4baf..2b2d2ac 100644
--- a/common/domain/typeimplementations.cpp
+++ b/common/domain/typeimplementations.cpp
@@ -65,7 +65,8 @@ typedef IndexConfig<Addressbook,
 
 typedef IndexConfig<Event,
         ValueIndex<Event::Uid>,
-        SortedIndex<Event::StartTime>
+        SortedIndex<Event::StartTime>,
+        SampledPeriodIndex<Event::StartTime, Event::EndTime>
     > EventIndexConfig;
 
 typedef IndexConfig<Todo,
diff --git a/common/domain/typeimplementations_p.h b/common/domain/typeimplementations_p.h
index fc08048..51af113 100644
--- a/common/domain/typeimplementations_p.h
+++ b/common/domain/typeimplementations_p.h
@@ -126,6 +126,26 @@ public:
     }
 };
 
+template <typename RangeBeginProperty, typename RangeEndProperty>
+class SampledPeriodIndex
+{
+    static_assert(std::is_same<typename RangeBeginProperty::Type, QDateTime>::value &&
+                      std::is_same<typename RangeEndProperty::Type, QDateTime>::value,
+        "Date range index is not supported for types other than 'QDateTime's");
+
+public:
+    static void configure(TypeIndex &index)
+    {
+        index.addSampledPeriodIndex<RangeBeginProperty, RangeEndProperty>();
+    }
+
+    template <typename EntityType>
+    static QMap<QByteArray, int> databases()
+    {
+        return {{QByteArray{EntityType::name} +".index." + RangeBeginProperty::name + ".range." + RangeEndProperty::name, 1}};
+    }
+};
+
 template <typename EntityType, typename ... Indexes>
 class IndexConfig
 {