YT-21233: Introduce TErrorAttributes as an opaque type for attributes to hide dependencies on IAttributeDictionary's API

Plan:

1) Remove `IAttributedDictionary` type from the public API. \+

2) Remove `Set` method from public API in favor of `operator<<=`. \+

3) Adopt `ConvertTo<T>` (or other name) CPO with proper extension into `NYT::NYson::ConvertTo` from `yt/core`.

4) Use CPO from (3) to eliminate direct dependency on `yt/core` of `Get/Find` methods from attributes API.

5) Adopt `ConvertToYsonString` (or other name) CPO with proper extension into `yt/core` customisations.

6) Use CPO from (5) to eliminate direct dependency on `yt/core` of `TErrorAttribute` ctor.

7) Swap attributes implementation to the one which doesn’t use `IAttributeDictionary`.

8) At this point `stripped_error*` can be moved to library/cpp/yt and so can recursively dependant on THROW macro methods `Get/Find/…`.

9) Adjust CPO’s to work with `std::string` instead of `TYsonString` assuming text format to be used (maybe `TString` for now).

10) Remove dep of `library/cpp/yt/error` on `yson` entirely.

This pull request covers steps 1 and 2 laying foundation to 3-4 being implemented in the next one
commit_hash:e899bccdef4ebed321ea2eb93215282694c261ac

6 files changed, 315 insertions, 0 deletions

diff --git a/library/cpp/yt/error/error_attributes-inl.h b/library/cpp/yt/error/error_attributes-inl.h
new file mode 100644
index 0000000000..a05e62d0e9
--- /dev/null
+++ b/library/cpp/yt/error/error_attributes-inl.h
@@ -0,0 +1,72 @@
+#ifndef ERROR_ATTRIBUTES_INL_H_
+#error "Direct inclusion of this file is not allowed, include error_attributes.h"
+// For the sake of sane code completion.
+#include "error_attributes.h"
+#endif
+
+namespace NYT {
+
+////////////////////////////////////////////////////////////////////////////////
+
+template <class T>
+T TErrorAttributes::GetAndRemove(const TString& key)
+{
+    auto result = Get<T>(key);
+    Remove(key);
+    return result;
+}
+
+template <class T>
+T TErrorAttributes::Get(TStringBuf key, const T& defaultValue) const
+{
+    return Find<T>(key).value_or(defaultValue);
+}
+
+template <class T>
+T TErrorAttributes::GetAndRemove(const TString& key, const T& defaultValue)
+{
+    auto result = Find<T>(key);
+    if (result) {
+        Remove(key);
+        return *result;
+    } else {
+        return defaultValue;
+    }
+}
+
+template <class T>
+typename TOptionalTraits<T>::TOptional TErrorAttributes::FindAndRemove(const TString& key)
+{
+    auto result = Find<T>(key);
+    if (result) {
+        Remove(key);
+    }
+    return result;
+}
+
+template <CMergeableDictionary TDictionary>
+void TErrorAttributes::MergeFrom(const TDictionary& dict)
+{
+    using TTraits = TMergeDictionariesTraits<TDictionary>;
+
+    for (const auto& [key, value] : TTraits::MakeIterableView(dict)) {
+        SetYson(key, value);
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+template <>
+struct TMergeDictionariesTraits<TErrorAttributes>
+{
+    static auto MakeIterableView(const TErrorAttributes& attributes)
+    {
+        return attributes.ListPairs();
+    }
+};
+
+static_assert(CMergeableDictionary<TErrorAttributes>);
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NYT
diff --git a/library/cpp/yt/error/error_attributes.cpp b/library/cpp/yt/error/error_attributes.cpp
new file mode 100644
index 0000000000..2c1b542314
--- /dev/null
+++ b/library/cpp/yt/error/error_attributes.cpp
@@ -0,0 +1,62 @@
+#include "error_attributes.h"
+
+namespace NYT {
+
+////////////////////////////////////////////////////////////////////////////////
+
+TErrorAttributes::TErrorAttributes(void* attributes)
+    : Attributes_(attributes)
+{ }
+
+void TErrorAttributes::Clear()
+{
+    for (const auto& key : ListKeys()) {
+        Remove(key);
+    }
+}
+
+NYson::TYsonString TErrorAttributes::GetYsonAndRemove(const TString& key)
+{
+    auto result = GetYson(key);
+    Remove(key);
+    return result;
+}
+
+bool TErrorAttributes::Contains(TStringBuf key) const
+{
+    return FindYson(key).operator bool();
+}
+
+bool operator == (const TErrorAttributes& lhs, const TErrorAttributes& rhs)
+{
+    auto lhsPairs = lhs.ListPairs();
+    auto rhsPairs = rhs.ListPairs();
+    if (lhsPairs.size() != rhsPairs.size()) {
+        return false;
+    }
+
+    std::sort(lhsPairs.begin(), lhsPairs.end(), [] (const auto& lhs, const auto& rhs) {
+        return lhs.first < rhs.first;
+    });
+    std::sort(rhsPairs.begin(), rhsPairs.end(), [] (const auto& lhs, const auto& rhs) {
+        return lhs.first < rhs.first;
+    });
+
+    for (auto index = 0; index < std::ssize(lhsPairs); ++index) {
+        if (lhsPairs[index].first != rhsPairs[index].first) {
+            return false;
+        }
+    }
+
+    for (auto index = 0; index < std::ssize(lhsPairs); ++index) {
+        if (lhsPairs[index].second != rhsPairs[index].second) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NYT
diff --git a/library/cpp/yt/error/error_attributes.h b/library/cpp/yt/error/error_attributes.h
new file mode 100644
index 0000000000..88771f8360
--- /dev/null
+++ b/library/cpp/yt/error/error_attributes.h
@@ -0,0 +1,105 @@
+#pragma once
+
+#include "mergeable_dictionary.h"
+
+#include <library/cpp/yt/misc/optional.h>
+
+namespace NYT {
+
+////////////////////////////////////////////////////////////////////////////////
+
+// For now this is just an opaque handle to error attributes
+// used to remove dependency on IAttributeDictionary in public API.
+// Eventually it would be a simple hash map.
+// NB(arkady-e1ppa): For now most methods are defined in yt/yt/core/misc/stripped_error.cpp
+// eventually they will be moved here.
+class TErrorAttributes
+{
+public:
+    using TKey = TString;
+    using TValue = NYson::TYsonString;
+    using TKeyValuePair = std::pair<TKey, TValue>;
+
+    //! Returns the list of all keys in the dictionary.
+    std::vector<TString> ListKeys() const;
+
+    //! Returns the list of all key-value pairs in the dictionary.
+    std::vector<TKeyValuePair> ListPairs() const;
+
+    //! Returns the value of the attribute (null indicates that the attribute is not found).
+    NYson::TYsonString FindYson(TStringBuf key) const;
+
+    //! Sets the value of the attribute.
+    void SetYson(const TString& key, const NYson::TYsonString& value);
+
+    //! Removes the attribute.
+    //! Returns |true| if the attribute was removed or |false| if there is no attribute with this key.
+    bool Remove(const TString& key);
+
+    //! Removes all attributes.
+    void Clear();
+
+    //! Returns the value of the attribute (throws an exception if the attribute is not found).
+    NYson::TYsonString GetYson(TStringBuf key) const;
+
+    //! Same as #GetYson but removes the value.
+    NYson::TYsonString GetYsonAndRemove(const TString& key);
+
+    //! Returns |true| iff the given key is present.
+    bool Contains(TStringBuf key) const;
+
+    // TODO(arkady-e1ppa): By default deserialization is located at yt/core
+    // consider using deserialization of some default types (guid, string, int, double)
+    // to be supported and everything else not supported without inclusion of yt/core.
+    //! Finds the attribute and deserializes its value.
+    //! Throws if no such value is found.
+    template <class T>
+    T Get(TStringBuf key) const;
+
+    //! Same as #Get but removes the value.
+    template <class T>
+    T GetAndRemove(const TString& key);
+
+    //! Finds the attribute and deserializes its value.
+    //! Uses default value if no such attribute is found.
+    template <class T>
+    T Get(TStringBuf key, const T& defaultValue) const;
+
+    //! Same as #Get but removes the value if it exists.
+    template <class T>
+    T GetAndRemove(const TString& key, const T& defaultValue);
+
+    //! Finds the attribute and deserializes its value.
+    //! Returns null if no such attribute is found.
+    template <class T>
+    typename TOptionalTraits<T>::TOptional Find(TStringBuf key) const;
+
+    //! Same as #Find but removes the value if it exists.
+    template <class T>
+    typename TOptionalTraits<T>::TOptional FindAndRemove(const TString& key);
+
+    template <CMergeableDictionary TDictionary>
+    void MergeFrom(const TDictionary& dict);
+
+private:
+    void* Attributes_; // IAttributesDictionary*
+
+    friend class TErrorOr<void>;
+    explicit TErrorAttributes(void* attributes);
+
+    TErrorAttributes(const TErrorAttributes& other) = default;
+    TErrorAttributes& operator= (const TErrorAttributes& other) = default;
+
+    TErrorAttributes(TErrorAttributes&& other) = default;
+    TErrorAttributes& operator= (TErrorAttributes&& other) = default;
+};
+
+bool operator == (const TErrorAttributes& lhs, const TErrorAttributes& rhs);
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NYT
+
+#define ERROR_ATTRIBUTES_INL_H_
+#include "error_attributes-inl.h"
+#undef ERROR_ATTRIBUTES_INL_H_
diff --git a/library/cpp/yt/error/mergeable_dictionary.h b/library/cpp/yt/error/mergeable_dictionary.h
new file mode 100644
index 0000000000..90597059e4
--- /dev/null
+++ b/library/cpp/yt/error/mergeable_dictionary.h
@@ -0,0 +1,57 @@
+#pragma once
+
+#include "public.h"
+
+#include <ranges>
+
+namespace NYT {
+
+////////////////////////////////////////////////////////////////////////////////
+
+// Can be specialized to make your dictionary satisfy CMergeableDictionary.
+template <class TDictionary>
+struct TMergeDictionariesTraits
+{
+    static auto MakeIterableView(const TDictionary& dict)
+        requires false;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+namespace NDetail {
+
+template <class T>
+struct TMergeableDictionaryImpl
+{
+    using TView = std::invoke_result_t<decltype(&TMergeDictionariesTraits<T>::MakeIterableView), const T&>;
+    using TIterator = std::ranges::iterator_t<TView>;
+    using TValue = typename std::iterator_traits<TIterator>::value_type;
+
+    static constexpr bool ValidSize = requires {
+        { std::tuple_size<TValue>::value } -> std::same_as<const size_t&>;
+    } && (std::tuple_size<TValue>::value == 2);
+
+    static constexpr bool CorrectTupleElements = requires {
+        typename std::tuple_element<0, TValue>::type;
+        std::same_as<typename std::tuple_element<0, TValue>::type, TString>;
+
+        typename std::tuple_element<1, TValue>::type;
+        std::same_as<typename std::tuple_element<1, TValue>::type, NYson::TYsonString>;
+    };
+};
+
+} // namespace NDetail
+
+////////////////////////////////////////////////////////////////////////////////
+
+template <class T>
+concept CMergeableDictionary =
+    requires (const T& dict) {
+        TMergeDictionariesTraits<T>::MakeIterableView(dict);
+    } &&
+    NDetail::TMergeableDictionaryImpl<T>::ValidSize &&
+    NDetail::TMergeableDictionaryImpl<T>::CorrectTupleElements;
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NYT
diff --git a/library/cpp/yt/error/public.h b/library/cpp/yt/error/public.h
new file mode 100644
index 0000000000..63b95497c7
--- /dev/null
+++ b/library/cpp/yt/error/public.h
@@ -0,0 +1,17 @@
+#pragma once
+
+#include <library/cpp/yt/yson_string/string.h>
+
+namespace NYT {
+
+////////////////////////////////////////////////////////////////////////////////
+
+template <class T>
+class TErrorOr;
+
+class TErrorAttributes;
+struct TOriginAttributes;
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NYT
diff --git a/library/cpp/yt/error/ya.make b/library/cpp/yt/error/ya.make
index f5bd946199..60d3e9a92f 100644
--- a/library/cpp/yt/error/ya.make
+++ b/library/cpp/yt/error/ya.make
@@ -9,9 +9,11 @@ PEERDIR(
     library/cpp/yt/misc
     library/cpp/yt/threading
     library/cpp/yt/string
+    library/cpp/yt/yson_string # TODO(arkady-e1ppa): eliminate
 )
 
 SRCS(
+    error_attributes.cpp
     origin_attributes.cpp
 )