From 30a93ab6b522538904bfafd1a5f16c5c517f4df4 Mon Sep 17 00:00:00 2001
From: Haavard <havardpe@yahoo-inc.com>
Date: Thu, 1 Sep 2016 12:45:45 +0000
Subject: SimpleConstantValue template replacing various wrappers

---
 .../eval/value_cache/constant_tensor_loader.cpp    | 29 ++++++----------------
 .../vespalib/eval/value_cache/constant_value.h     | 15 +++++++++++
 2 files changed, 23 insertions(+), 21 deletions(-)

(limited to 'vespalib/src')

diff --git a/vespalib/src/vespa/vespalib/eval/value_cache/constant_tensor_loader.cpp b/vespalib/src/vespa/vespalib/eval/value_cache/constant_tensor_loader.cpp
index a44a1e0ea53..501171083b4 100644
--- a/vespalib/src/vespa/vespalib/eval/value_cache/constant_tensor_loader.cpp
+++ b/vespalib/src/vespa/vespalib/eval/value_cache/constant_tensor_loader.cpp
@@ -66,42 +66,28 @@ struct AddressExtractor : ObjectTraverser {
     }
 };
 
-struct LoadError : ConstantValue {
-    ValueType my_type;
-    ErrorValue my_value;
-    LoadError() : my_type(ValueType::error_type()), my_value() {}
-    const ValueType &type() const override { return my_type; }
-    const Value &value() const override { return my_value; }
-};
-
-struct TensorConstant : ConstantValue {
-    ValueType my_type;
-    TensorValue my_value;
-    TensorConstant(std::unique_ptr<Tensor> tensor)
-        : my_type(tensor->engine().type_of(*tensor)), my_value(std::move(tensor)) {}
-    const ValueType &type() const override { return my_type; }
-    const Value &value() const override { return my_value; }
-};
-
 } // namespace vespalib::eval::<unnamed>
 
+using ErrorConstant = SimpleConstantValue<ErrorValue>;
+using TensorConstant = SimpleConstantValue<TensorValue>;
+
 ConstantValue::UP
 ConstantTensorLoader::create(const vespalib::string &path, const vespalib::string &type) const
 {
     ValueType value_type = ValueType::from_spec(type);
     if (value_type.is_error()) {
         LOG(warning, "invalid type specification: %s", type.c_str());
-        return std::make_unique<LoadError>();
+        return std::make_unique<ErrorConstant>(ValueType::error_type());
     }
     File file(path);
     if (!file.valid()) {
         LOG(warning, "could not read file: %s", path.c_str());
-        return std::make_unique<LoadError>();
+        return std::make_unique<ErrorConstant>(ValueType::error_type());
     }
     Slime slime;
     if (slime::JsonFormat::decode(Memory(file.data, file.size), slime) == 0) {
         LOG(warning, "file contains invalid json: %s", path.c_str());
-        return std::make_unique<LoadError>();
+        return std::make_unique<ErrorConstant>(ValueType::error_type());
     }
     std::set<vespalib::string> indexed;
     for (const auto &dimension: value_type.dimensions()) {
@@ -117,7 +103,8 @@ ConstantTensorLoader::create(const vespalib::string &path, const vespalib::strin
         cells[i]["address"].traverse(extractor);
         spec.add(address, cells[i]["value"].asDouble());
     }
-    return std::make_unique<TensorConstant>(_engine.create(spec));
+    auto tensor = _engine.create(spec);
+    return std::make_unique<TensorConstant>(_engine.type_of(*tensor), std::move(tensor));
 }
 
 } // namespace vespalib::eval
diff --git a/vespalib/src/vespa/vespalib/eval/value_cache/constant_value.h b/vespalib/src/vespa/vespalib/eval/value_cache/constant_value.h
index fbdb32ede88..570276a50ab 100644
--- a/vespalib/src/vespa/vespalib/eval/value_cache/constant_value.h
+++ b/vespalib/src/vespa/vespalib/eval/value_cache/constant_value.h
@@ -21,6 +21,21 @@ struct ConstantValue {
     virtual ~ConstantValue() {}
 };
 
+/**
+ * A simple implementation of a constant value that bundles together a
+ * ValueType instance with a specific Value subclass instance.
+ **/
+template <typename VALUE>
+struct SimpleConstantValue : ConstantValue {
+    ValueType my_type;
+    VALUE my_value;
+    template <typename... Args>
+    SimpleConstantValue(const ValueType &type_in, Args &&...args)
+        : my_type(type_in), my_value(std::forward<Args>(args)...) {}
+    const ValueType &type() const override { return my_type; }
+    const Value &value() const override { return my_value; }
+};
+
 /**
  * An abstract factory of constant values. The typical use-case for
  * this will be to load constant values from file with a cache on top
-- 
cgit v1.2.3