Add ReadableAttributeVector accessor to IAttributeManager

Provides a unified interface for fetching both regular as well as
imported attributes. Exposing `ReadableAttributeVector` instead of
raw `AttributeVector` instances enforces that all access is done via
appropriate acquired read guards.

Refactor document selection processing code to use the new interface
in order to prepare for imported field support in selections.

1 files changed, 4 insertions, 0 deletions

diff --git a/searchsummary/src/tests/docsummary/positionsdfw_test.cpp b/searchsummary/src/tests/docsummary/positionsdfw_test.cpp
index b161958fc43..4cad98a8e01 100644
--- a/searchsummary/src/tests/docsummary/positionsdfw_test.cpp
+++ b/searchsummary/src/tests/docsummary/positionsdfw_test.cpp
@@ -100,6 +100,10 @@ public:
     IAttributeContext::UP createContext() const override {
         return IAttributeContext::UP(new MyAttributeContext(_attr));
     }
+
+    std::shared_ptr<attribute::ReadableAttributeVector> readable_attribute_vector(const string&) const override {
+        LOG_ABORT("should not be reached");
+    }
 };
 
 struct MyGetDocsumsStateCallback : GetDocsumsStateCallback {